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doi: 10.15886/j.cnki.rdswxb.20250007
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To further explore the key genes regulating drought resistance in soybean, the peroxidase gene GmPOD123, which is significantly induced under drought stress, was screened based on previous transcriptomic analyses (RNA-Seq) of soybean leaves under drought stress. An expression analysis of the soybean GmPOD123 gene under drought stress was performed to identify whether GmPOD123 is involved in response to drought stress, and the results showed that GmPOD123 was significantly up-regulated after 3 h stress treatment. Moreover, phenotype identification of transgenic Arabidopsis plants of overexpressing GmPOD123 showed that overexpression of GmPOD123 in Arabidopsis could increase the drought tolerance, which was compared to wild type Arabidopsis. To further explore the drought-resistant molecular mechanism of GmPOD123, fructose-1,6-bisphosphate aldolase (GmFBA2), an interacting protein of GmPOD123, was screened from the soybean cDNA yeast library by Mating, and its interaction with GmPOD123 was identified by yeast two-hybrid system and luciferase complementation assay (LCA). In summary, GmFBA2 may influence ROS levels by interacting with GmPOD123, thereby regulating soybean drought resistance.
To further explore the key genes regulating drought resistance in soybean, the peroxidase gene GmPOD123, which is significantly induced under drought stress, was screened based on previous transcriptomic analyses (RNA-Seq) of soybean leaves under drought stress. An expression analysis of the soybean GmPOD123 gene under drought stress was performed to identify whether GmPOD123 is involved in response to drought stress, and the results showed that GmPOD123 was significantly up-regulated after 3 h stress treatment. Moreover, phenotype identification of transgenic Arabidopsis plants of overexpressing GmPOD123 showed that overexpression of GmPOD123 in Arabidopsis could increase the drought tolerance, which was compared to wild type Arabidopsis. To further explore the drought-resistant molecular mechanism of GmPOD123, fructose-1,6-bisphosphate aldolase (GmFBA2), an interacting protein of GmPOD123, was screened from the soybean cDNA yeast library by Mating, and its interaction with GmPOD123 was identified by yeast two-hybrid system and luciferase complementation assay (LCA). In summary, GmFBA2 may influence ROS levels by interacting with GmPOD123, thereby regulating soybean drought resistance.
Accepted Manuscript
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doi: 10.15886/j.cnki.rdswxb.20240161
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Torulaspora delbrueckii is one of non-Saccharomyces yeasts mostly used for research, and is widely used for brewing of various fruit wines. It is co-fermented with Saccharomyces cerevisiae for improving fruit wine flavors. In this experiment, a wild-type yeast strain was selected from the peel of cantaloupe in Fulo Town, Ledong County, Hainan Province. Through phenotypic observation of the strain and constructing a phylogenetic tree based on 18S rDNA sequencing, the strain was identified as T. delbrueckii. Under the fermentation condition of fruit wine, T. delbrueckii grew normally in the range of alcohol content 4−20%, pH value 2.8−3.6 and sulfur dioxide concentration 100−500 mg·L−1, and the growth rate was the highest under the condition of alcohol content 4%, pH value 3.6 and sulfur dioxide concentration 300 mg·L−1. The results show that T. delbrueckii did not produce hydrogen sulfide, had no killing effect on S. cerevisiae, and improved the flavor of cantaloupe fruit wine, which can be used in the production of cantaloupe fruit wine.
Torulaspora delbrueckii is one of non-Saccharomyces yeasts mostly used for research, and is widely used for brewing of various fruit wines. It is co-fermented with Saccharomyces cerevisiae for improving fruit wine flavors. In this experiment, a wild-type yeast strain was selected from the peel of cantaloupe in Fulo Town, Ledong County, Hainan Province. Through phenotypic observation of the strain and constructing a phylogenetic tree based on 18S rDNA sequencing, the strain was identified as T. delbrueckii. Under the fermentation condition of fruit wine, T. delbrueckii grew normally in the range of alcohol content 4−20%, pH value 2.8−3.6 and sulfur dioxide concentration 100−500 mg·L−1, and the growth rate was the highest under the condition of alcohol content 4%, pH value 3.6 and sulfur dioxide concentration 300 mg·L−1. The results show that T. delbrueckii did not produce hydrogen sulfide, had no killing effect on S. cerevisiae, and improved the flavor of cantaloupe fruit wine, which can be used in the production of cantaloupe fruit wine.
Accepted Manuscript
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doi: 10.15886/j.cnki.rdswxb.20240152
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The fitness cost of resistance to dimefluthrin in Aedes albopictus was analyzed by population life table comparison method using the resistant line (RR) of Ae. albopictus for experiment with the susceptible line SS as control. The results showed that the net reproduction rate (R0), mean generation time (T), intrinsic rate of increase (rm), finite rate of increase (λ), and population doubling time (D) were 41.13, 11.77 d, 0.32 d−1, 1.38 d−1, and 2.17 d, respectively, for the susceptible line population, and. 26.48, 14.27 d, 0.23 d−1, 1.26 d−1, and 3.01 d, respectively, for the resistant line. The resistant line of Ae. albopictus was longer in population doubling time than the susceptible line, indicating that its reproductive rate has slowed down. The pupation rate and emergence rate of the susceptible and resistant lines were all 100%, indicating there was no significant difference between them. The average development time from first instar larvae to pupae was 9.66±0.17 d for the susceptible line and 11.31±0.17 d for the resistant line; the average emergence time of pupae for both of the lines was 2.15±0.04 d and 2.90±0.03 d, respectively; the average survival time of female mosquitoes was 30.03±1.60 d and 21.83±1.12 d, respectively, for both of the lines, and there were all significant differences. The development time of larval and pupal stages and the life span of adult mosquitoes were prolonged, indicating that there is a certain fitness cost of resistance to dimefluthrin in Ae. albopictus.
The fitness cost of resistance to dimefluthrin in Aedes albopictus was analyzed by population life table comparison method using the resistant line (RR) of Ae. albopictus for experiment with the susceptible line SS as control. The results showed that the net reproduction rate (R0), mean generation time (T), intrinsic rate of increase (rm), finite rate of increase (λ), and population doubling time (D) were 41.13, 11.77 d, 0.32 d−1, 1.38 d−1, and 2.17 d, respectively, for the susceptible line population, and. 26.48, 14.27 d, 0.23 d−1, 1.26 d−1, and 3.01 d, respectively, for the resistant line. The resistant line of Ae. albopictus was longer in population doubling time than the susceptible line, indicating that its reproductive rate has slowed down. The pupation rate and emergence rate of the susceptible and resistant lines were all 100%, indicating there was no significant difference between them. The average development time from first instar larvae to pupae was 9.66±0.17 d for the susceptible line and 11.31±0.17 d for the resistant line; the average emergence time of pupae for both of the lines was 2.15±0.04 d and 2.90±0.03 d, respectively; the average survival time of female mosquitoes was 30.03±1.60 d and 21.83±1.12 d, respectively, for both of the lines, and there were all significant differences. The development time of larval and pupal stages and the life span of adult mosquitoes were prolonged, indicating that there is a certain fitness cost of resistance to dimefluthrin in Ae. albopictus.
Accepted Manuscript
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doi: 10.15886/j.cnki.rdswxb.20240173
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An attempt was made to make full use of the advantages of plant extracts and chemical pesticides to reduce the dosage of chemical pesticides. Syzygium infrarubiginosum was extracted with methanol, and mixed with four chemical fungicides, including ethirimol, pyraclostrobin, thifluzamide and difenoconazole to screen the synergistic ratio of their mixtures against Rhizoctonia solani, the pathogen of rice sheath blight by indoor activity determination of mycelial growth rate of R. solani. The control effects of the synergistic mixtures on rice sheath blight and cowpea powdery mildew were determined by indoor pot experiment. The indoor activity determination showed that the mixtures at 11 ratios were found to have significant synergistic effects in the indoor activity determination of rice sheath blight, including the mixture of 5% (w/w) methanol extract microemulsion with 5% (w/w) pyraclostrobin suspension at the ratios of 4:1 and 5:1 ratio (the synergistic coefficient was 2.349 and 2.987, respectively), with 5% thifluzamide suspension at the respective ratios of 1:3, 1:4 and 1:5 (the synergistic coefficient values were 2.714, 2.455 and 2.167, respectively). The pot experiment showed that the mixtures screened could effectively control the occurrence of rice sheath blight and cowpea powdery mildew.
An attempt was made to make full use of the advantages of plant extracts and chemical pesticides to reduce the dosage of chemical pesticides. Syzygium infrarubiginosum was extracted with methanol, and mixed with four chemical fungicides, including ethirimol, pyraclostrobin, thifluzamide and difenoconazole to screen the synergistic ratio of their mixtures against Rhizoctonia solani, the pathogen of rice sheath blight by indoor activity determination of mycelial growth rate of R. solani. The control effects of the synergistic mixtures on rice sheath blight and cowpea powdery mildew were determined by indoor pot experiment. The indoor activity determination showed that the mixtures at 11 ratios were found to have significant synergistic effects in the indoor activity determination of rice sheath blight, including the mixture of 5% (w/w) methanol extract microemulsion with 5% (w/w) pyraclostrobin suspension at the ratios of 4:1 and 5:1 ratio (the synergistic coefficient was 2.349 and 2.987, respectively), with 5% thifluzamide suspension at the respective ratios of 1:3, 1:4 and 1:5 (the synergistic coefficient values were 2.714, 2.455 and 2.167, respectively). The pot experiment showed that the mixtures screened could effectively control the occurrence of rice sheath blight and cowpea powdery mildew.
Accepted Manuscript
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doi: 10.15886/j.cnki.rdswxb.20240175
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To explore the evolutionary history of the Bradyrhizobium and its plastic degradation-related gene the hydroxylase gene CYP450, and to understand the mechanisms by which the genus acquires its plastic degradation potential. In this study, 28 fully assembled strains of Bradyrhizobium were collected to investigate the evolution and dissemination of Bradyrhizobium and their hydroxylase genes CYP450 through comparative genomic and phylogenetic analyses. The results revealed that, compared to the core genes, the unique and accessory genes of Bradyrhizobium exhibited an increase in functions related to plastic degradation, such as membrane transport, xenobiotic biodegradation and metabolism, lipid metabolism, and signal transduction. Bradyrhizobium has an open pan-genome, enabling it to acquire genes from other species, adapt to new environments, and evolve new functions. Analysis of the flow of the hydroxylase gene CYP450 in bacteria and archaea revealed that Bradyrhizobium likely acquired hydroxylase gene CYP450 from the Actinobacteria phylum through horizontal gene transfer, thus gaining the potential for plastic degradation.
To explore the evolutionary history of the Bradyrhizobium and its plastic degradation-related gene the hydroxylase gene CYP450, and to understand the mechanisms by which the genus acquires its plastic degradation potential. In this study, 28 fully assembled strains of Bradyrhizobium were collected to investigate the evolution and dissemination of Bradyrhizobium and their hydroxylase genes CYP450 through comparative genomic and phylogenetic analyses. The results revealed that, compared to the core genes, the unique and accessory genes of Bradyrhizobium exhibited an increase in functions related to plastic degradation, such as membrane transport, xenobiotic biodegradation and metabolism, lipid metabolism, and signal transduction. Bradyrhizobium has an open pan-genome, enabling it to acquire genes from other species, adapt to new environments, and evolve new functions. Analysis of the flow of the hydroxylase gene CYP450 in bacteria and archaea revealed that Bradyrhizobium likely acquired hydroxylase gene CYP450 from the Actinobacteria phylum through horizontal gene transfer, thus gaining the potential for plastic degradation.
Accepted Manuscript
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doi: 10.15886/j.cnki.rdswxb.20240176
Abstract:
An attempt was made to investigate the expression of lactate dehydrogenase (ptLDHA), a key enzyme in lactate metabolism, and to explore the acetylation modification sites on ptLDHA and their potential role in the interplay between lactylation and acetylation modifications in Phaeodactylum tricornutum Bohlin. The ptLDHA gene sequence was first cloned from P. tricornutum Bohlin cDNA, and then a prokaryotic expression vector, pMBP-C-LDHA, was constructed. The recombinant plasmid was then transferred into Escherichia coli BL21 (DE3) for induced expression. Under optimized conditions (16℃, 0.2 mmol·L−1 IPTG for 24 hours), ptLDHA protein was successfully expressed, predominantly in a soluble form. The fusion protein was purified using His-tag affinity chromatography and identified by Western blot with ptLDHA polyclonal antibodies. A single protein band at approximately 78 kDa was observed, confirming that the purified protein was ptLDHA. The expression and purification of ptLDHA in prokaryotic cells was successfully established, laying foundations for subsequent site-directed mutagenesis of acetylation modification sites and for investigation of the effects of modification and demodification on enzyme activity.
An attempt was made to investigate the expression of lactate dehydrogenase (ptLDHA), a key enzyme in lactate metabolism, and to explore the acetylation modification sites on ptLDHA and their potential role in the interplay between lactylation and acetylation modifications in Phaeodactylum tricornutum Bohlin. The ptLDHA gene sequence was first cloned from P. tricornutum Bohlin cDNA, and then a prokaryotic expression vector, pMBP-C-LDHA, was constructed. The recombinant plasmid was then transferred into Escherichia coli BL21 (DE3) for induced expression. Under optimized conditions (16℃, 0.2 mmol·L−1 IPTG for 24 hours), ptLDHA protein was successfully expressed, predominantly in a soluble form. The fusion protein was purified using His-tag affinity chromatography and identified by Western blot with ptLDHA polyclonal antibodies. A single protein band at approximately 78 kDa was observed, confirming that the purified protein was ptLDHA. The expression and purification of ptLDHA in prokaryotic cells was successfully established, laying foundations for subsequent site-directed mutagenesis of acetylation modification sites and for investigation of the effects of modification and demodification on enzyme activity.
Accepted Manuscript
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doi: 10.15886/j.cnki.rdswxb.20240138
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In order to fully understand the reasonable nutrients of Yunnan rubber (Hevea brasiliensis) forest, soil ecological restoration of rubber forest provides data support. Using the soil of Yunnan (Jinghong, Hekou, Ruili), the typical samples of 20 m 20 m in different rubber forests, the soil samples were stratified (0−20, 20−40, 40−60, 60−80, 80−100 cm), and the spatial distribution characteristics of the soil of the rubber forest soil with the forest age and the dynamic changes were analyzed. The result show that the soil TC, TN, and TP contents in the rubber plantations generally increased and then decreased with the plantation age and soil depth. Significant differences were observed in the soil TC, TN, and TP contents among different ages of rubber plantations in Ruili and Jinghong, while the differences in Hekou were not significant. In Jinghong, the soil C∶N ratio increased and then decreased with soil depth, reaching its highest value at (40−60 cm). The soil C∶P ratio decreased with increasing soil depth, peaking at the surface layer (0−20 cm). The N∶P ratio initially decreased and then increased with soil depth. The C∶P and N∶P ratios showed a trend of decreasing and then increasing, with the highest values at 40−60 cm. In Ruili, the C∶N and C∶P ratios decreased and then increased with soil depth, also peaking at 40−60 cm, while the N∶P ratio continuously decreased. In Hekou, the C∶P ratio decreased and then increased with soil depth, while both C∶P and N∶P ratios showed a general decreasing trend. The contents of soil nutrients (C, N, P) and their ecological stoichiometric ratios in rubber plantations generally increased and then decreased with plantation age. Significant differences were found in the soil C, N, P contents and their stoichiometric ratios among different ages and soil layers in the rubber plantations (P<0.05), with highly significant differences observed between areas (P<0.01). It is suggested that during the rapid growth stage of rubber plantations, appropriate application of nitrogen and phosphorus fertilizers should be considered, as the soil N and P affect the growth of mature rubber plantations.
In order to fully understand the reasonable nutrients of Yunnan rubber (Hevea brasiliensis) forest, soil ecological restoration of rubber forest provides data support. Using the soil of Yunnan (Jinghong, Hekou, Ruili), the typical samples of 20 m 20 m in different rubber forests, the soil samples were stratified (0−20, 20−40, 40−60, 60−80, 80−100 cm), and the spatial distribution characteristics of the soil of the rubber forest soil with the forest age and the dynamic changes were analyzed. The result show that the soil TC, TN, and TP contents in the rubber plantations generally increased and then decreased with the plantation age and soil depth. Significant differences were observed in the soil TC, TN, and TP contents among different ages of rubber plantations in Ruili and Jinghong, while the differences in Hekou were not significant. In Jinghong, the soil C∶N ratio increased and then decreased with soil depth, reaching its highest value at (40−60 cm). The soil C∶P ratio decreased with increasing soil depth, peaking at the surface layer (0−20 cm). The N∶P ratio initially decreased and then increased with soil depth. The C∶P and N∶P ratios showed a trend of decreasing and then increasing, with the highest values at 40−60 cm. In Ruili, the C∶N and C∶P ratios decreased and then increased with soil depth, also peaking at 40−60 cm, while the N∶P ratio continuously decreased. In Hekou, the C∶P ratio decreased and then increased with soil depth, while both C∶P and N∶P ratios showed a general decreasing trend. The contents of soil nutrients (C, N, P) and their ecological stoichiometric ratios in rubber plantations generally increased and then decreased with plantation age. Significant differences were found in the soil C, N, P contents and their stoichiometric ratios among different ages and soil layers in the rubber plantations (P<0.05), with highly significant differences observed between areas (P<0.01). It is suggested that during the rapid growth stage of rubber plantations, appropriate application of nitrogen and phosphorus fertilizers should be considered, as the soil N and P affect the growth of mature rubber plantations.
Accepted Manuscript
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doi: 10.15886/j.cnki.rdswxb.20240199
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To explore the role of jasmonate-induced oxygenases JOX family genes in the growth, development, and stress resistance of cassava (Manihot esculenta), MeJOXs family members were identified in cassava genome by bioinformatics methods, and their gene structure, promoter cis-acting elements, evolutionary relationships and expression patterns were analyzed. The results showed that there were four MeJOXs family genes in cassava genome, and each member had similar gene structure, conserved motifs, and protein domains. Each gene member exhibited at least 68% protein homology, with the highest similarity observed between MeJOX1 and MeJOX4, as well as between MeJOX2 and MeJOX3. Promoter cis-acting elements analysis showed that MeJOXs contained numerous light-responsive elements. Furthermore, each gene member possessed a varying number of hormone-responsive elements. Phylogenetic analysis showed that MeJOXs were more closely related to JOX genes in dicotyledonous plants. Transcriptome analysis revealed that all the genes were differentially expressed in stems, leaves, midveins, and fibrous roots, with the exception of MeJOX2 that was scarcely expressed in various cassava tissues. MeJOXs were induced by MeJA in different cassava germplasm, with MeJOX3 demonstrating the most significant expression by inducing. Upon infection by pathogen Xpm, MeJOX1/3/4 responded promptly, but their response patterns were distinctly different. MeJOX1/3 were upregulated, whereas MeJOX4 exhibited a trend of downregulation, and MeJOX2 exhibited negligible response. This study provides a theoretical foundation for further elucidating the functions of the MeJOXs gene family in cassava.
To explore the role of jasmonate-induced oxygenases JOX family genes in the growth, development, and stress resistance of cassava (Manihot esculenta), MeJOXs family members were identified in cassava genome by bioinformatics methods, and their gene structure, promoter cis-acting elements, evolutionary relationships and expression patterns were analyzed. The results showed that there were four MeJOXs family genes in cassava genome, and each member had similar gene structure, conserved motifs, and protein domains. Each gene member exhibited at least 68% protein homology, with the highest similarity observed between MeJOX1 and MeJOX4, as well as between MeJOX2 and MeJOX3. Promoter cis-acting elements analysis showed that MeJOXs contained numerous light-responsive elements. Furthermore, each gene member possessed a varying number of hormone-responsive elements. Phylogenetic analysis showed that MeJOXs were more closely related to JOX genes in dicotyledonous plants. Transcriptome analysis revealed that all the genes were differentially expressed in stems, leaves, midveins, and fibrous roots, with the exception of MeJOX2 that was scarcely expressed in various cassava tissues. MeJOXs were induced by MeJA in different cassava germplasm, with MeJOX3 demonstrating the most significant expression by inducing. Upon infection by pathogen Xpm, MeJOX1/3/4 responded promptly, but their response patterns were distinctly different. MeJOX1/3 were upregulated, whereas MeJOX4 exhibited a trend of downregulation, and MeJOX2 exhibited negligible response. This study provides a theoretical foundation for further elucidating the functions of the MeJOXs gene family in cassava.
Accepted Manuscript
, Available online ,
doi: 10.15886/j.cnki.rdswxb.20240177
Abstract:
In order to understand the anti-actinomycetes with biocontrol value isolated and screened from the soil in Hainan Island, actinomycetes were isolated from six soil samples from different regions of Hainan by using a gradient dilution method, and the actinomycete strains were screened by using the confrontation culture method and identified based on their morphology, physiological and biochemical characteristics and molecular biology methods. The potential application value of the active strains was determined by fruit soaking method and pot experiment. A total of 285 actinomycete strains were isolated from the soil samples, and the strain Q2-02 had the highest antibacterial activity. Its inhibition rates of Botryodiplodia theobromae, Colletotrichum gloeosporioides and Rhizoctonia solani were 92.8%, 90.0% and 88.2%, respectively, and the inhibition rates of the other six pathogens were also more than 60.0%. The identification of this strain showed that the strain Q2-02 was Streptomyces lunalinharesii. The pot experiments showed that the control effect of the 10-fold dilution of the fermented supernatant of the strain on mango stemend rot and rice sheath blight was significantly higher than that of the positive control 45% thiophandazim suspension diluted 800 times and 10% validacin aqueous solution diluted1000 times, indicating that the strain Q2-02 has the value of further development and application.
In order to understand the anti-actinomycetes with biocontrol value isolated and screened from the soil in Hainan Island, actinomycetes were isolated from six soil samples from different regions of Hainan by using a gradient dilution method, and the actinomycete strains were screened by using the confrontation culture method and identified based on their morphology, physiological and biochemical characteristics and molecular biology methods. The potential application value of the active strains was determined by fruit soaking method and pot experiment. A total of 285 actinomycete strains were isolated from the soil samples, and the strain Q2-02 had the highest antibacterial activity. Its inhibition rates of Botryodiplodia theobromae, Colletotrichum gloeosporioides and Rhizoctonia solani were 92.8%, 90.0% and 88.2%, respectively, and the inhibition rates of the other six pathogens were also more than 60.0%. The identification of this strain showed that the strain Q2-02 was Streptomyces lunalinharesii. The pot experiments showed that the control effect of the 10-fold dilution of the fermented supernatant of the strain on mango stemend rot and rice sheath blight was significantly higher than that of the positive control 45% thiophandazim suspension diluted 800 times and 10% validacin aqueous solution diluted
Accepted Manuscript
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doi: 10.15886/j.cnki.rdswxb.20240169
Abstract:
Cassava is an important food crop in tropical regions, but the yield of cassava is affected by salt stress, which endangers food security. JAZ (jasmonate ZIM-domain, JAZ) proteins, as essential components in the jasmonate signaling pathway, are involved in regulating the tolerance to salt stress in a variety of crops. In order to investigate response of JAZ proteins in cassava to salt stress, as well as the underlying regulatory mechanisms two homologous genes MeJAZ2.1 and MeJAZ2.2 were identified from cassava variety SC124 through bioinformatics. The evolutionary tree and conserved domain analysis indicated that they both contain two conserved domains, ZIM and Jas, which belong to the JAZ gene family. Further research discovered that the expression level of MeJAZ2.2 changed more significantly in response to salt stress in cassava. MeJAZ2.2-silenced cassava plants were more susceptibility to salt stress compared to the wild type, indicating that MeJAZ2.2 may positively regulate cassava resistance to salt stress. The pGADT7-MeJAZ2.2 bait vector was constructed and no self-activating activity was found by yeast two-hybrid experiment. Moreover, three candidate interacting proteins of MeJAZ2.2 were screened, including glutamine synthetase (GS), ubiquitin 3 (Ub3), and FRIGIDA-LIKE PROTEIN (FRI-L), which provides a preliminary framework for analyzing the function and molecular mechanism of JAZ proteins to salt stress in cassava.
Cassava is an important food crop in tropical regions, but the yield of cassava is affected by salt stress, which endangers food security. JAZ (jasmonate ZIM-domain, JAZ) proteins, as essential components in the jasmonate signaling pathway, are involved in regulating the tolerance to salt stress in a variety of crops. In order to investigate response of JAZ proteins in cassava to salt stress, as well as the underlying regulatory mechanisms two homologous genes MeJAZ2.1 and MeJAZ2.2 were identified from cassava variety SC124 through bioinformatics. The evolutionary tree and conserved domain analysis indicated that they both contain two conserved domains, ZIM and Jas, which belong to the JAZ gene family. Further research discovered that the expression level of MeJAZ2.2 changed more significantly in response to salt stress in cassava. MeJAZ2.2-silenced cassava plants were more susceptibility to salt stress compared to the wild type, indicating that MeJAZ2.2 may positively regulate cassava resistance to salt stress. The pGADT7-MeJAZ2.2 bait vector was constructed and no self-activating activity was found by yeast two-hybrid experiment. Moreover, three candidate interacting proteins of MeJAZ2.2 were screened, including glutamine synthetase (GS), ubiquitin 3 (Ub3), and FRIGIDA-LIKE PROTEIN (FRI-L), which provides a preliminary framework for analyzing the function and molecular mechanism of JAZ proteins to salt stress in cassava.
Accepted Manuscript
, Available online ,
doi: 10.15886/j.cnki.rdswxb.20240116
Abstract:
To explore the volatile components and aroma composition of the flowers of longan (Dimocarpus longan), and to investigate the antioxidant activity of their extracts, the flowers of longan were collected from Fujian and extracted with different solvents, and their volatile components and the aroma of the components were analyzed by using the GC-MS technology. Meanwhile, DPPH and ABTS free radical scavenging assays were used to detect the antioxidant activity of the longan flower extracts. The results showed that 59 components were identified from the essential oil extracted from the longan flowers, accounting for approximately 82.2% of the total volatile components. In the essential oil 4 key aroma compounds, 3 potential aroma compounds and 1 modified aroma compound were found. The DPPH and ABTS free radical scavenging assay showed that different solvent extracts of longan flowers had a certain degree of antioxidant activity. Water extract, methanol extract and ethanol extract had significant antioxidant activity, while n-butyl alcohol extract and ethyl acetate extract had low antioxidant activity. All the results show that longan flowers have a great development potential in the fields of medicine, cosmetics, health products, functional foods and so on, which provides a scientific basis for the development and utilization of longan flowers.
To explore the volatile components and aroma composition of the flowers of longan (Dimocarpus longan), and to investigate the antioxidant activity of their extracts, the flowers of longan were collected from Fujian and extracted with different solvents, and their volatile components and the aroma of the components were analyzed by using the GC-MS technology. Meanwhile, DPPH and ABTS free radical scavenging assays were used to detect the antioxidant activity of the longan flower extracts. The results showed that 59 components were identified from the essential oil extracted from the longan flowers, accounting for approximately 82.2% of the total volatile components. In the essential oil 4 key aroma compounds, 3 potential aroma compounds and 1 modified aroma compound were found. The DPPH and ABTS free radical scavenging assay showed that different solvent extracts of longan flowers had a certain degree of antioxidant activity. Water extract, methanol extract and ethanol extract had significant antioxidant activity, while n-butyl alcohol extract and ethyl acetate extract had low antioxidant activity. All the results show that longan flowers have a great development potential in the fields of medicine, cosmetics, health products, functional foods and so on, which provides a scientific basis for the development and utilization of longan flowers.
Accepted Manuscript
, Available online ,
doi: 10.15886/j.cnki.rdswxb.20240147
Abstract:
Cassava (Manihot esculenta Crantz) has important economic value. Exploring the key genes of cassava is of great significance for improving cassava quality. To mine disease-resistant genes of cassava, a specific immune receptor-related gene resistant to Xam (MeRXam2) was cloned, and its protein structure was analyzed. The analysis was found that the coding sequence (CDS) region of this gene is3561 bp, with the protein size of about 132.847 kD, Real-time fluorescent quantitative (Real-time quantitative reverse transcription PCR, qRT-PCR) analysis showed that the expression level of MeRXam2 increased with time under pathogen infection and reached the maximum at 24 h, indicating that MeRXam2 was involved in the resistance response to cassava disease. In addition, a MeRXam2-pET32a protein expression vector was constructed by homologous recombination, and the protein was induced and determined. After exogenous spraying of MeRXam2 protein on cassava leaf tissues, the number of bacteria was found significantly lower than that of the control strain, indicating that this protein could slow down bacterial infection. This founding might provide a theoretical basis and candidate protein for cassava molecular breeding.
Cassava (Manihot esculenta Crantz) has important economic value. Exploring the key genes of cassava is of great significance for improving cassava quality. To mine disease-resistant genes of cassava, a specific immune receptor-related gene resistant to Xam (MeRXam2) was cloned, and its protein structure was analyzed. The analysis was found that the coding sequence (CDS) region of this gene is
Accepted Manuscript
, Available online ,
doi: 10.15886/j.cnki.rdswxb.20240170
Abstract:
The endoplasmic reticulum (ER) serves as a crucial site for protein processing in eukaryotic cells. Sec62, an essential component of the ER translocation complex, plays a significant role in growth, development, and stress regulation. An attempt was made to examine the transcription levels of the PcSec62 gene at various growth stages and during pathogenic processes. The PcSec62 gene was knocked out by using CRISPR/Cas9 gene editing to produce knockout mutants (ΔPcsec62) and a complementary strain (ΔPcsec62-C). The results showed that the transcriptional expression of PcSec62 significantly increased during the sporangia and infection stages. The ΔPcsec62 mutants exhibited notably reduced growth and sporulation abilities, alongside stunted hyphal growth. Additionally, the ΔPcsec62 strain showed significantly low tolerance to abiotic stress and reduced pathogenicity. These findings indicate that PcSec62 is involved in regulating the growth, development, abiotic stress responses, and pathogenicity of Phytophthora capsici.
The endoplasmic reticulum (ER) serves as a crucial site for protein processing in eukaryotic cells. Sec62, an essential component of the ER translocation complex, plays a significant role in growth, development, and stress regulation. An attempt was made to examine the transcription levels of the PcSec62 gene at various growth stages and during pathogenic processes. The PcSec62 gene was knocked out by using CRISPR/Cas9 gene editing to produce knockout mutants (ΔPcsec62) and a complementary strain (ΔPcsec62-C). The results showed that the transcriptional expression of PcSec62 significantly increased during the sporangia and infection stages. The ΔPcsec62 mutants exhibited notably reduced growth and sporulation abilities, alongside stunted hyphal growth. Additionally, the ΔPcsec62 strain showed significantly low tolerance to abiotic stress and reduced pathogenicity. These findings indicate that PcSec62 is involved in regulating the growth, development, abiotic stress responses, and pathogenicity of Phytophthora capsici.
Accepted Manuscript
, Available online ,
doi: 10.15886/j.cnki.rdswxb.20240149
Abstract:
The bactericidal effects of different antibiotics on Escherichia coli were analyzed by using fluorescence photoelectric microbial detection devices. The results prove that the antimicrobial analysis using fluorescence photoelectric microbial detection devices is equivalent to the K-B disk diffusion method. Compared to the traditional methods, the fluorescence photoelectric microbial detection method can be used to quickly identify microbial resistance in clinical specimens, especially of fastidious bacteria and other slow-growing strains, providing timely reference for the clinical application of antibiotics and drug resistance analysis of pathogens. The detection of the drug resistance of E. coli to 9 antibiotics showed that E. coli had the highest resistance to nalidixic acid, with a minimal inhibitory concentration (MIC) of 100 μg/mL. E. coli had the lowest resistance to cefotaxime, with a minimal inhibitory concentration of 0.2 μg/mL. Combination of nalidixic acid with ciprofloxacin, cefotaxime, or chloramphenicol indicated that the combination of 0.5 MIC concentration of nalidixic acid with 0.5 MIC concentration of ciprofloxacin had the best bactericidal effect.
The bactericidal effects of different antibiotics on Escherichia coli were analyzed by using fluorescence photoelectric microbial detection devices. The results prove that the antimicrobial analysis using fluorescence photoelectric microbial detection devices is equivalent to the K-B disk diffusion method. Compared to the traditional methods, the fluorescence photoelectric microbial detection method can be used to quickly identify microbial resistance in clinical specimens, especially of fastidious bacteria and other slow-growing strains, providing timely reference for the clinical application of antibiotics and drug resistance analysis of pathogens. The detection of the drug resistance of E. coli to 9 antibiotics showed that E. coli had the highest resistance to nalidixic acid, with a minimal inhibitory concentration (MIC) of 100 μg/mL. E. coli had the lowest resistance to cefotaxime, with a minimal inhibitory concentration of 0.2 μg/mL. Combination of nalidixic acid with ciprofloxacin, cefotaxime, or chloramphenicol indicated that the combination of 0.5 MIC concentration of nalidixic acid with 0.5 MIC concentration of ciprofloxacin had the best bactericidal effect.
Accepted Manuscript
, Available online ,
doi: 10.15886/j.cnki.rdswxb.20240140
Abstract:
Solanum lycopersicum is a model plant for research in genetics and molecular biology. Recently selection of tomato internal reference genes has been reported but with less types of exogenous hormones used for treatment. An attempt was hence made to select internal reference genes with stable expression in different tissues of tomato and under treatment with plant hormones. DANJ, EF-1α, ACT, UBI, APT, CAC, TIP41 and RPL8 were used as candidate internal reference genes, and selected under the 8 experimental conditions: exogenous hormone treatment with auxin, gibberellin, abscisic acid, cytokinin, salicylic acid, brassinolide and ethylene and various plant parts. The stability of the candidate reference genes was comprehensively evaluated using algorithms such as geNorm, NormFinder, BestKeeper, Delta CT and RefFinder. The stability of the reference genes was validated using the auxin-responsive gene SlGH3.4. The results showed that APT is the most stable reference gene expressed in auxin, gibberellin, abscisic acid, brassinosteroid treatment and various plant parts, that UBI is the most stable reference gene expressed in all samples under cytokinin and salicylic acid treatment, and that TIP41 is the most stable reference gene expressed under ethylene treatment. Finally, when APT, which has a relatively stable comprehensive ranking, was used as an internal reference gene, it was found that the expression level of SlGH3.4 gene showed a similar trend under IAA treatment conditions, while the less stable RPL8 gene failed to accurately correct the expression level of the target gene. All these results may provide theoretical support for the analysis of gene expression networks and molecular regulatory mechanisms in the response of tomato to exogenous hormone treatment.
Solanum lycopersicum is a model plant for research in genetics and molecular biology. Recently selection of tomato internal reference genes has been reported but with less types of exogenous hormones used for treatment. An attempt was hence made to select internal reference genes with stable expression in different tissues of tomato and under treatment with plant hormones. DANJ, EF-1α, ACT, UBI, APT, CAC, TIP41 and RPL8 were used as candidate internal reference genes, and selected under the 8 experimental conditions: exogenous hormone treatment with auxin, gibberellin, abscisic acid, cytokinin, salicylic acid, brassinolide and ethylene and various plant parts. The stability of the candidate reference genes was comprehensively evaluated using algorithms such as geNorm, NormFinder, BestKeeper, Delta CT and RefFinder. The stability of the reference genes was validated using the auxin-responsive gene SlGH3.4. The results showed that APT is the most stable reference gene expressed in auxin, gibberellin, abscisic acid, brassinosteroid treatment and various plant parts, that UBI is the most stable reference gene expressed in all samples under cytokinin and salicylic acid treatment, and that TIP41 is the most stable reference gene expressed under ethylene treatment. Finally, when APT, which has a relatively stable comprehensive ranking, was used as an internal reference gene, it was found that the expression level of SlGH3.4 gene showed a similar trend under IAA treatment conditions, while the less stable RPL8 gene failed to accurately correct the expression level of the target gene. All these results may provide theoretical support for the analysis of gene expression networks and molecular regulatory mechanisms in the response of tomato to exogenous hormone treatment.
Accepted Manuscript
, Available online ,
doi: 10.15886/j.cnki.rdswxb.20240158
Abstract:
Research on the central nervous system function of pests forms the foundation for developing precise behavior control technologies. Despite the significant role of neuron-labeling techniques based on genetic manipulation in this field, such techniques remain relatively scarce for non-model insects, such as the oriental fruit fly, Bactrocera dorsalis. In this context an attempt was made to identify four pan-neuronal expression genes in B. dorsalis with a view to laying the groundwork for constructing a neuron-labeling system for this species. The genomic structures of the pan-neuronal expression genes in B. dorsalis were identified and analyzed by employing bioinformatics and molecular biology to verify their full-length sequences and peripheral expression patterns. The results indicate that, by referring to four pan-neuronal expression genes from Drosophila, four homologous genes were identified in the B. dorsalis, namely BdornSyb, BdorSyt1, Bdorelav, and BdorBrp. The full genomic lengths of these four genes are 19,337 bp (5 exons, 4 introns), 26,884 bp (8 exons, 7 introns), 1,341 bp (1 exon), and 49,692 bp (14 exons, 13 introns), respectively. The domains of BdornSyb, BdorSyt1, and Bdorelav are highly conserved among closely related species. PCR cloning results indicated that the CDS sequence lengths of these four genes are all over 500 bp, consistent with the bioinformatics analysis results. Evolutionary and genomic structure analyses demonstrated that the four genes are highly conserved among Diptera insects. Expression pattern analysis revealed that all the four genes are expressed in the peripheral sensory organs of B. dorsalis, with three genes, BdornSyb, BdorSyt1 and BdorBrp, showing higher expression levels in the primary olfactory organs, the antennae, and the maxillary palp. The four genes identified are candidate pan-neuronal expression genes in B. dorsalis, providing a foundation for constructing a pan-neuronal labeling system for this species in the future.
Research on the central nervous system function of pests forms the foundation for developing precise behavior control technologies. Despite the significant role of neuron-labeling techniques based on genetic manipulation in this field, such techniques remain relatively scarce for non-model insects, such as the oriental fruit fly, Bactrocera dorsalis. In this context an attempt was made to identify four pan-neuronal expression genes in B. dorsalis with a view to laying the groundwork for constructing a neuron-labeling system for this species. The genomic structures of the pan-neuronal expression genes in B. dorsalis were identified and analyzed by employing bioinformatics and molecular biology to verify their full-length sequences and peripheral expression patterns. The results indicate that, by referring to four pan-neuronal expression genes from Drosophila, four homologous genes were identified in the B. dorsalis, namely BdornSyb, BdorSyt1, Bdorelav, and BdorBrp. The full genomic lengths of these four genes are 19,337 bp (5 exons, 4 introns), 26,884 bp (8 exons, 7 introns), 1,341 bp (1 exon), and 49,692 bp (14 exons, 13 introns), respectively. The domains of BdornSyb, BdorSyt1, and Bdorelav are highly conserved among closely related species. PCR cloning results indicated that the CDS sequence lengths of these four genes are all over 500 bp, consistent with the bioinformatics analysis results. Evolutionary and genomic structure analyses demonstrated that the four genes are highly conserved among Diptera insects. Expression pattern analysis revealed that all the four genes are expressed in the peripheral sensory organs of B. dorsalis, with three genes, BdornSyb, BdorSyt1 and BdorBrp, showing higher expression levels in the primary olfactory organs, the antennae, and the maxillary palp. The four genes identified are candidate pan-neuronal expression genes in B. dorsalis, providing a foundation for constructing a pan-neuronal labeling system for this species in the future.
Accepted Manuscript
, Available online ,
doi: 10.15886/j.cnki.rdswxb.20240073
Abstract:
Exploring the spatial ecological niche delineation between co-distributed proximate species is crucial to understand their coexistence in the community. A survey of two species of pheasants, Red Junglefowl (Gallus gallus jabouillei) and Chinese Francolin (Francolinus pintadeanus), were made at 105 and 79 distribution sites in Datian National Nature Reserve, Hainan, from March 2023 to January 2024, respectively, using the line transect method and satellite tracking technology. A maximum entropy model was used to predict the suitable habitats for these two species of pheasants by combining 12 environmental variables, and analyze their overlap. The results showed that there are differences in the distribution patterns of suitable habitats for the two species of pheasants. The suitable habitat for the Red Junglefowl was located in the north-western and central parts of the reserve, which are dominated by deciduous broad-leaved and scrub forests, while the suitable habitat of the Chinese Francolin was located in the northern part of the reserve, and was mainly in the grass area. The potential suitable habitats of the two species of pheasants were 633.18 hm2 and 337.31 hm2, accounting for 48.61% and 25.89% of the area of the reserve, respectively. The ecological overlap indices of the Red Junglefowl and the Chinese Francolin were low, with D and I values being 0.421 and 0.711, respectively, and the overlapping area of suitable habitat was 41.31 hm2, which accounted for 17.64% and 17.22% of the area of the suitable habitats for the Red Junglefowl and the Chinese Francolin, respectively. There were similarities and differences in the selection of environmental factors by the two species. Differences lie in the fact that the variables with the greatest influence on the habitat distribution of the two species of pheasants were the distance from the ranger path and the normalized difference vegetation index (NDVI), which are mainly manifested in the fact that the Red Junglefowl preferred deciduous broad-leaved forests and scrubs near the ranger paths, whereas the Chinese Francolin was more influenced by the NDVI; similarities lie in the fact that the variable with the second highest influence on the habitat distribution of the two species of pheasants was the distance from the water source, which was manifested in the fact that the Red Junglefowl and the Chinese Francolin preferred to distribute within 400 m and 500～1000 m from water sources, respectively. This survey reveals a spatial sympatric niche relationship between the Red Junglefowl and the Chinese Francolin, and helps to further understand the interspecific competition and coexistence mechanisms of tropical pheasants.
Exploring the spatial ecological niche delineation between co-distributed proximate species is crucial to understand their coexistence in the community. A survey of two species of pheasants, Red Junglefowl (Gallus gallus jabouillei) and Chinese Francolin (Francolinus pintadeanus), were made at 105 and 79 distribution sites in Datian National Nature Reserve, Hainan, from March 2023 to January 2024, respectively, using the line transect method and satellite tracking technology. A maximum entropy model was used to predict the suitable habitats for these two species of pheasants by combining 12 environmental variables, and analyze their overlap. The results showed that there are differences in the distribution patterns of suitable habitats for the two species of pheasants. The suitable habitat for the Red Junglefowl was located in the north-western and central parts of the reserve, which are dominated by deciduous broad-leaved and scrub forests, while the suitable habitat of the Chinese Francolin was located in the northern part of the reserve, and was mainly in the grass area. The potential suitable habitats of the two species of pheasants were 633.18 hm2 and 337.31 hm2, accounting for 48.61% and 25.89% of the area of the reserve, respectively. The ecological overlap indices of the Red Junglefowl and the Chinese Francolin were low, with D and I values being 0.421 and 0.711, respectively, and the overlapping area of suitable habitat was 41.31 hm2, which accounted for 17.64% and 17.22% of the area of the suitable habitats for the Red Junglefowl and the Chinese Francolin, respectively. There were similarities and differences in the selection of environmental factors by the two species. Differences lie in the fact that the variables with the greatest influence on the habitat distribution of the two species of pheasants were the distance from the ranger path and the normalized difference vegetation index (NDVI), which are mainly manifested in the fact that the Red Junglefowl preferred deciduous broad-leaved forests and scrubs near the ranger paths, whereas the Chinese Francolin was more influenced by the NDVI; similarities lie in the fact that the variable with the second highest influence on the habitat distribution of the two species of pheasants was the distance from the water source, which was manifested in the fact that the Red Junglefowl and the Chinese Francolin preferred to distribute within 400 m and 500～
Accepted Manuscript
, Available online ,
doi: 10.15886/j.cnki.rdswxb.20230143
Abstract:
The rubber tree (Hevea brasiliensis) is an important economic crop in tropical areas of China, and its related industries play an important role in the local agricultural economy. The powdery mildew fungus Erysiphe quercicola is the most severe disease infecting H. brasiliensis. The effector proteins secreted by phytopahogenic microbes play important roles in the pathogenesis, but how effector proteins promote the infection by E. quercicola is less documented, which has limited disease resistance breeding programme and disease control strategies. The E. quercicola has 24 highly conserved candidate effector proteins, which has homologous in many other powdery mildews. It is possible that these proteins are required for the pathogenicity of powdery mildew. In order to find the important virulence factor among the 24 CSEPs, two conserved effector proteins were selected for functional analysis and found that only the effector CSEP00565 suppressed hypersensitive responses induced by Phytophthora infestans INF1 when these effectors were expressed in Nicotiana benthamiana. The effector CSEP00565 suppressed callose deposition induced by fungal chitin and bacteria flg22 when this effector was expressed in Arabidopsis thaliana, further supporting that CSEP00565 has a function to inhibit plant immunity. When CSEP00565 was further silenced by using spray-induced gene, the pathogenicity of the fungus significantly decreased. And the expression level of CSEP00565 was up-regulated at the haustorium formation stage (24 h) after inoculation with E. quercicola. Further research has discovered that the signal peptide of CSEP00565 possesses the activity of direct protein secretion. All these results indicate that CSEP00565 is a key virulence factor in promoting the infection by E. quercicola, which is conducive to understanding of the molecular mechanisms underlying H. brasiliensis-E. quercicola interaction.
The rubber tree (Hevea brasiliensis) is an important economic crop in tropical areas of China, and its related industries play an important role in the local agricultural economy. The powdery mildew fungus Erysiphe quercicola is the most severe disease infecting H. brasiliensis. The effector proteins secreted by phytopahogenic microbes play important roles in the pathogenesis, but how effector proteins promote the infection by E. quercicola is less documented, which has limited disease resistance breeding programme and disease control strategies. The E. quercicola has 24 highly conserved candidate effector proteins, which has homologous in many other powdery mildews. It is possible that these proteins are required for the pathogenicity of powdery mildew. In order to find the important virulence factor among the 24 CSEPs, two conserved effector proteins were selected for functional analysis and found that only the effector CSEP00565 suppressed hypersensitive responses induced by Phytophthora infestans INF1 when these effectors were expressed in Nicotiana benthamiana. The effector CSEP00565 suppressed callose deposition induced by fungal chitin and bacteria flg22 when this effector was expressed in Arabidopsis thaliana, further supporting that CSEP00565 has a function to inhibit plant immunity. When CSEP00565 was further silenced by using spray-induced gene, the pathogenicity of the fungus significantly decreased. And the expression level of CSEP00565 was up-regulated at the haustorium formation stage (24 h) after inoculation with E. quercicola. Further research has discovered that the signal peptide of CSEP00565 possesses the activity of direct protein secretion. All these results indicate that CSEP00565 is a key virulence factor in promoting the infection by E. quercicola, which is conducive to understanding of the molecular mechanisms underlying H. brasiliensis-E. quercicola interaction.
Accepted Manuscript
, Available online ,
doi: 10.15886/j.cnki.rdswxb.20240111
Abstract:
As an important part of Hainan's agriculture, rice industry in Hainan has unique development advantages, high-quality tropical natural conditions and abundant light and heat resources. The current situation of rice industry in Hainan was analyzed in terms of planting area, production, rice varieties and branding. The analysis showed that there are major problems in rice production in Hainan, such as high cost, low yield and no premium. In order to solve these problems and promote the green and efficient development of Hainan's rice industry, a series of countermeasures are proposed, including promoting intelligent mechanised planting to reduce costs, relying on scientific and technological innovations to improve rice yield, implementing green production modes to improve the quality and efficiency of rice, as well as strengthening brand building and market promotion. The comprehensive application of these countermeasures aims to improve the market competitiveness of Hainan rice, achieve a win-win situation in terms of ecological and economic benefits, and promote the sustainable development of rice industry in Hainan.
As an important part of Hainan's agriculture, rice industry in Hainan has unique development advantages, high-quality tropical natural conditions and abundant light and heat resources. The current situation of rice industry in Hainan was analyzed in terms of planting area, production, rice varieties and branding. The analysis showed that there are major problems in rice production in Hainan, such as high cost, low yield and no premium. In order to solve these problems and promote the green and efficient development of Hainan's rice industry, a series of countermeasures are proposed, including promoting intelligent mechanised planting to reduce costs, relying on scientific and technological innovations to improve rice yield, implementing green production modes to improve the quality and efficiency of rice, as well as strengthening brand building and market promotion. The comprehensive application of these countermeasures aims to improve the market competitiveness of Hainan rice, achieve a win-win situation in terms of ecological and economic benefits, and promote the sustainable development of rice industry in Hainan.
Articles online first have been peer-reviewed and accepted, which are not yet assigned to volumes /issues, but are citable by Digital Object Identifier (DOI).
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2024, 15(3): 259-267.
doi: 10.15886/j.cnki.rdswxb.20230031
Abstract:
Ash content and moisture content are important indexes for cassava quality evaluation. It is of great significance to establish a method for rapid detection of ash and moisture contents in cassava by using near infrared spectroscopy combined with multivariate mathematical analysis. Tubers of 137 accessions of cassava were harvested at the cassava growing site and their ash and water contents were determined by using the methods described in the standards GB5009.3—2016 and GB/T5009.4—2016 and at the same time the near-infrared spectroscopy. The NIR spectral data collected were analyzed by using the software TQ Analyst 9.0. The NIR calibration models for ash and water contents of cassava were constructed by using the partial least squares (PLS) method. The results showed that correlation coefficients (R) of the ash and water content models were 0.94 and 0.93, respectively. Root mean square error of correction (RMSEC) was 0.22 and 0.48, respectively. Root mean square error of prediction (RMSEP) was 0.21 and 1.46, respectively. Root mean square error of cross-validation (RMSECV) was 0.40 and 1.54, respectively. Twenty accessions of cassava germplasm that were not involved in the modelling were selected for external validation of the model. The results showed that there is no significant difference between the predicted value and the actual value, with the p-values (P>0.05) being 0.464 and 0.459, respectively, indicating that the model could be applied to the detection of cassava ash and water contents. The near-infrared quantitative detection models of ash and moisture established can be used for rapid detection.
Ash content and moisture content are important indexes for cassava quality evaluation. It is of great significance to establish a method for rapid detection of ash and moisture contents in cassava by using near infrared spectroscopy combined with multivariate mathematical analysis. Tubers of 137 accessions of cassava were harvested at the cassava growing site and their ash and water contents were determined by using the methods described in the standards GB5009.3—2016 and GB/T5009.4—2016 and at the same time the near-infrared spectroscopy. The NIR spectral data collected were analyzed by using the software TQ Analyst 9.0. The NIR calibration models for ash and water contents of cassava were constructed by using the partial least squares (PLS) method. The results showed that correlation coefficients (R) of the ash and water content models were 0.94 and 0.93, respectively. Root mean square error of correction (RMSEC) was 0.22 and 0.48, respectively. Root mean square error of prediction (RMSEP) was 0.21 and 1.46, respectively. Root mean square error of cross-validation (RMSECV) was 0.40 and 1.54, respectively. Twenty accessions of cassava germplasm that were not involved in the modelling were selected for external validation of the model. The results showed that there is no significant difference between the predicted value and the actual value, with the p-values (P>0.05) being 0.464 and 0.459, respectively, indicating that the model could be applied to the detection of cassava ash and water contents. The near-infrared quantitative detection models of ash and moisture established can be used for rapid detection.
2024, 15(3): 268-271.
doi: 10.15886/j.cnki.rdswxb.20230064
Abstract:
Limnophila sessiliflora var. jiulianshanensis G.L.Xu, a new variety of L. sessiliflora (Vahl) Blume from Jiangxi Jiulianshan National Nature Reserve in China was recorded based on its morphological evidence. This variety is morphologically very similar to L. sessiliflora (Vahl) Blume var. sessiliflora but its aerial stems and calyxes are glabrous, with a pair of 1-3 mm bracteoles each flower, and five raised purplish-red stripes on calyxes in flowering and fruiting periods, distinguished from the latter.
Limnophila sessiliflora var. jiulianshanensis G.L.Xu, a new variety of L. sessiliflora (Vahl) Blume from Jiangxi Jiulianshan National Nature Reserve in China was recorded based on its morphological evidence. This variety is morphologically very similar to L. sessiliflora (Vahl) Blume var. sessiliflora but its aerial stems and calyxes are glabrous, with a pair of 1-3 mm bracteoles each flower, and five raised purplish-red stripes on calyxes in flowering and fruiting periods, distinguished from the latter.
2024, 15(3): 272-280.
doi: 10.15886/j.cnki.rdswxb.20230096
Abstract:
In order to investigate the effects of short-term precipitation reduction on the changes of organic carbon mineralization rate and its carbon fractions in different soil layers, parameters such as soil organic carbon mineralization rate and organic carbon fractions under different precipitation conditions were determined by building a field isolated penetrating rain control platform and combining with indoor constant temperature incubation experiments using a typical plantation type of rubber forest soils in Hainan as the research object. The results showed that the short-term precipitation decreased the cumulative mineralization of SOC, the mineralization rate and the microbial metabolic entropy (qCO2) in the soil layer from 0 to 10 cm, and the contents of easily oxidizable organic carbon (EOC), microbial biomass carbon (MBC) and inert organic carbon (NEOC) decreased with the decrease of the soil water content, but the effect was only significant on the EOC in the soil layer from 0 to 10 cm. Correlation analysis showed that the cumulative mineralization of soil SOC and the mineralization rate of SOC were both significantly and positively correlated with soil carbon and nitrogen contents (SOC, TN), the contents of each carbon fraction (EOC, MBC, NEOC), and qCO2. In conclusion, short-term precipitation reduction inhibited the mineralization of SOC in rubber forest soils, and this change may be closely related to the effectiveness of soil substrate supply and changes in microbial metabolism under different moisture conditions.
In order to investigate the effects of short-term precipitation reduction on the changes of organic carbon mineralization rate and its carbon fractions in different soil layers, parameters such as soil organic carbon mineralization rate and organic carbon fractions under different precipitation conditions were determined by building a field isolated penetrating rain control platform and combining with indoor constant temperature incubation experiments using a typical plantation type of rubber forest soils in Hainan as the research object. The results showed that the short-term precipitation decreased the cumulative mineralization of SOC, the mineralization rate and the microbial metabolic entropy (qCO2) in the soil layer from 0 to 10 cm, and the contents of easily oxidizable organic carbon (EOC), microbial biomass carbon (MBC) and inert organic carbon (NEOC) decreased with the decrease of the soil water content, but the effect was only significant on the EOC in the soil layer from 0 to 10 cm. Correlation analysis showed that the cumulative mineralization of soil SOC and the mineralization rate of SOC were both significantly and positively correlated with soil carbon and nitrogen contents (SOC, TN), the contents of each carbon fraction (EOC, MBC, NEOC), and qCO2. In conclusion, short-term precipitation reduction inhibited the mineralization of SOC in rubber forest soils, and this change may be closely related to the effectiveness of soil substrate supply and changes in microbial metabolism under different moisture conditions.
2024, 15(3): 281-289.
doi: 10.15886/j.cnki.rdswxb.20230073
Abstract:
In recent years the rapid proliferation of Derris trifoliata populations in mangrove areas has resulted in extensive mortality of mangrove plants in certain regions, posing a serious threat to the mangrove wetland ecosystem. During field investigations it was observed that the impact of D. trifoliata on mangrove plants was more pronounced in areas with shorter flooding durations and lower salinity levels compared to those with longer flooding durations and higher salinity levels. To investigate the underlying causes of this phenomenon, an attempt was made to simulate 25 different tidal environments through controlled artificial experiments, under which D. trifoliata seedlings were raised to observe variations in antioxidant enzyme activity, osmotic regulation mechanisms, and membrane system damage levels in their leaves. The results demonstrated that under the individual influence of salinity and flood, the activities of superoxide dismutase (SOD) and catalase (CAT) in the leaves of D. trifoliata seedlings initially increased and then decreased at a salinity level of 0—40‰. The peak value was observed at a salinity level of 20‰. In D. trifoliata seedlings SOD and CAT activities in the leaves did not show significant changes during the 0 h/d-8 h/d flooding period. However, free proline (FPRO) and malondialdehyde (MDA) contents in the seedling leaves exhibited an increasing trend with salinity levels and flooding duration, and their maximum values were reached under treatment conditions of 40‰ salinity and 8 h/d flooding. When both salinity levels and flooding duration were put together, the SOD activity, CAT activity, FPRO content, and MDA content in the seedling leaves came to peak under the treatment of 20‰ salt for 6 h/d, 20‰ salt for 8 h/d, and 40‰ salt for 8 h/d, respectively. In summary, in an environment with short flooding durations and low salinity levels, D. trifoliata seedlings exhibited a heightened capacity for antioxidant enzymes to combat stress-induced damage, resulting in normal growth and consequently a relatively significant impact on mangrove plants. Conversely, in an environment with prolonged flooding duration and high salinity levels, the efficacy of antioxidant enzymes in mitigating stress damage was diminished, leading to inhibited growth and consequently a relatively less influence on the mangrove plants.
In recent years the rapid proliferation of Derris trifoliata populations in mangrove areas has resulted in extensive mortality of mangrove plants in certain regions, posing a serious threat to the mangrove wetland ecosystem. During field investigations it was observed that the impact of D. trifoliata on mangrove plants was more pronounced in areas with shorter flooding durations and lower salinity levels compared to those with longer flooding durations and higher salinity levels. To investigate the underlying causes of this phenomenon, an attempt was made to simulate 25 different tidal environments through controlled artificial experiments, under which D. trifoliata seedlings were raised to observe variations in antioxidant enzyme activity, osmotic regulation mechanisms, and membrane system damage levels in their leaves. The results demonstrated that under the individual influence of salinity and flood, the activities of superoxide dismutase (SOD) and catalase (CAT) in the leaves of D. trifoliata seedlings initially increased and then decreased at a salinity level of 0—40‰. The peak value was observed at a salinity level of 20‰. In D. trifoliata seedlings SOD and CAT activities in the leaves did not show significant changes during the 0 h/d-8 h/d flooding period. However, free proline (FPRO) and malondialdehyde (MDA) contents in the seedling leaves exhibited an increasing trend with salinity levels and flooding duration, and their maximum values were reached under treatment conditions of 40‰ salinity and 8 h/d flooding. When both salinity levels and flooding duration were put together, the SOD activity, CAT activity, FPRO content, and MDA content in the seedling leaves came to peak under the treatment of 20‰ salt for 6 h/d, 20‰ salt for 8 h/d, and 40‰ salt for 8 h/d, respectively. In summary, in an environment with short flooding durations and low salinity levels, D. trifoliata seedlings exhibited a heightened capacity for antioxidant enzymes to combat stress-induced damage, resulting in normal growth and consequently a relatively significant impact on mangrove plants. Conversely, in an environment with prolonged flooding duration and high salinity levels, the efficacy of antioxidant enzymes in mitigating stress damage was diminished, leading to inhibited growth and consequently a relatively less influence on the mangrove plants.
2024, 15(3): 290-298.
doi: 10.15886/j.cnki.rdswxb.20220110
Abstract:
Essential oil was extracted from floral buds and leaves of Michelia shiluensis (M. shiluensis) by steam distillation. After treatment, the components of the essential oil were determined by gas chromatography-mass spectrometry (GC-MS). The GC-MS analysis showed that the main components of the two essential oils were sesquiterpenes. A total of 39 chemical components were identified from the essential oil of floral buds, of which three, β-bisabolene, α-curcumene and β-elemene, were the highest in relative content. A total of 31 chemical constituents were identified from the essential oil of leaves, including guaiacol, isoguaiacol, (Z, Z, Z) -1,8,11,14-heptadecatetraene, and so on. The relative content of alc cohols and olefins is an important index to distinguish between the essential oils of the floral buds and the leaves. The components of M. shiluensis essential oil were analyzed for the first time, and the inhibitory activity of M. shiluensis essential oil on α-glucosidase was determined. When the mass concentration was 3 g·L-1, the essential oils of the leaves and floral buds had an inhibition rate of 87.13% and 72.27% against α-glucosidase activity, and their IC50 was 0.73 ± 0.04 g·L-1 and 1.77 ± 0.07 g·L-1, respectively. M. shiluensis essential oil has a strong inhibitory effect on α-glucosidase activity, and can be developed and used as a hypoglycemic efficacy factor, which provides a theoretical basis for value-added utilization of M. shiluensis resources.
Essential oil was extracted from floral buds and leaves of Michelia shiluensis (M. shiluensis) by steam distillation. After treatment, the components of the essential oil were determined by gas chromatography-mass spectrometry (GC-MS). The GC-MS analysis showed that the main components of the two essential oils were sesquiterpenes. A total of 39 chemical components were identified from the essential oil of floral buds, of which three, β-bisabolene, α-curcumene and β-elemene, were the highest in relative content. A total of 31 chemical constituents were identified from the essential oil of leaves, including guaiacol, isoguaiacol, (Z, Z, Z) -1,8,11,14-heptadecatetraene, and so on. The relative content of alc cohols and olefins is an important index to distinguish between the essential oils of the floral buds and the leaves. The components of M. shiluensis essential oil were analyzed for the first time, and the inhibitory activity of M. shiluensis essential oil on α-glucosidase was determined. When the mass concentration was 3 g·L-1, the essential oils of the leaves and floral buds had an inhibition rate of 87.13% and 72.27% against α-glucosidase activity, and their IC50 was 0.73 ± 0.04 g·L-1 and 1.77 ± 0.07 g·L-1, respectively. M. shiluensis essential oil has a strong inhibitory effect on α-glucosidase activity, and can be developed and used as a hypoglycemic efficacy factor, which provides a theoretical basis for value-added utilization of M. shiluensis resources.
2024, 15(3): 299-305.
doi: 10.15886/j.cnki.rdswxb.20230042
Abstract:
An attempt was made to analyze the effect of rhizobia on seedling growth of Falcataria falcata, which could provide scientific basis for the application of rhizobia in seedling cultivation of F. falcata. A rhizobium strain ZS530-8 isolated and purified was used as an inoculant, and an inoculation and nutrient application comparative trial was made in different culture substrates. Seedling height and ground diameter were regularly measured to analyze the differences in seedling growth dynamics and growth effects in different treatments. From planting to 30 d, the seedlings of F. falcata grew normally in different treatments, and the difference in seedling height was only observed in the different culture substrates. The growth rate of seedling height and ground diameter of the inoculated seedlings gradually increased from 30 d to 60 d, and the growth peak occurred from 60 d to 90 d, showing a trend of steady and then accelerated growth. The seedlings treated with nutrients maintained a trend of continuous growth at a certain rate, while the control failed to grow normally after 60 d. At 90 d, the height and ground diameter of inoculated seedlings were 8.18-10.10 cm and 1.67-2.14 mm, which were 3.2%-9.4% and 16.0%-33.8% higher than those of the nutrient treated seedlings in the corresponding substrates, respectively. The ground diameter of the quartz sand + rhizobia treatment was consistently better than that of the vermiculite + rhizobia treatment, and the difference reached a highly significant level (P<0.001). Rhizobia provide nitrogen-based essential nutrient elements for the growth of the seedlings of F. falcata, and have a significant effect on the growth of the seedlings, especially the growth of seedling ground diameter, and their growth-promoting effect is enhanced with the growth of the seedlings. The culture substrates with stable, loose and well-aerated texture and pH neutral acid are more conducive to growth-promoting of rhizobia.
An attempt was made to analyze the effect of rhizobia on seedling growth of Falcataria falcata, which could provide scientific basis for the application of rhizobia in seedling cultivation of F. falcata. A rhizobium strain ZS530-8 isolated and purified was used as an inoculant, and an inoculation and nutrient application comparative trial was made in different culture substrates. Seedling height and ground diameter were regularly measured to analyze the differences in seedling growth dynamics and growth effects in different treatments. From planting to 30 d, the seedlings of F. falcata grew normally in different treatments, and the difference in seedling height was only observed in the different culture substrates. The growth rate of seedling height and ground diameter of the inoculated seedlings gradually increased from 30 d to 60 d, and the growth peak occurred from 60 d to 90 d, showing a trend of steady and then accelerated growth. The seedlings treated with nutrients maintained a trend of continuous growth at a certain rate, while the control failed to grow normally after 60 d. At 90 d, the height and ground diameter of inoculated seedlings were 8.18-10.10 cm and 1.67-2.14 mm, which were 3.2%-9.4% and 16.0%-33.8% higher than those of the nutrient treated seedlings in the corresponding substrates, respectively. The ground diameter of the quartz sand + rhizobia treatment was consistently better than that of the vermiculite + rhizobia treatment, and the difference reached a highly significant level (P<0.001). Rhizobia provide nitrogen-based essential nutrient elements for the growth of the seedlings of F. falcata, and have a significant effect on the growth of the seedlings, especially the growth of seedling ground diameter, and their growth-promoting effect is enhanced with the growth of the seedlings. The culture substrates with stable, loose and well-aerated texture and pH neutral acid are more conducive to growth-promoting of rhizobia.
2024, 15(3): 306-314.
doi: 10.15886/j.cnki.rdswxb.20230118
Abstract:
In order to meet the needs of development of pitaya industry, it is necessary to develop numerous commercial varieties of pitaya with high yield and high quality through breeding and selection. The main way for pitaya breeding is to collect and evaluate pitaya germplasm resources for cross-breeding. Pitaya germplasm is diverse, and its genetic ploidy is unknown. The ploidy identification is indispensable to breeding innovation. Forty two accessions of pitaya germplasm were collected and their ploidy was identified by stem tip chromosome preparation technique and flow cytometry. When the current hypotonic time is 2 h, the dissociation time is 1.5 h, the enzymatic hydrolysis time is 1 h, and the post-hypotonic time is 30 min, the cells prepared are intact with good chromosome dispersion and clear background and without overlapping. The ploidy of the pitaya stem tip is stable, and the stem tip is the most reliable material for chromosome determination. The mature stems contain a large number of tetraploid and octaploid cells, and are hence not suitable for ploidy identification. Among the 42 accessions of pitaya germplasm there are 41 accessions diploid, 1 tetraploid and no triploid. The genome size was estimated with accession ‘Jindu No.1’ as a reference. It was found that 15 accessions of pitaya germplasm were very small in genome size with the 1C-value (1C) being ≤1.34 Gb while 27 accessions of pitaya germplasm were small in genome size with the 1C being in the range of 1.35 Gb~3.34 Gb. The identification of the ploidy of 42 accessions of pitaya germplasm might provide some reference for parent selection in pitaya cross breeding.
In order to meet the needs of development of pitaya industry, it is necessary to develop numerous commercial varieties of pitaya with high yield and high quality through breeding and selection. The main way for pitaya breeding is to collect and evaluate pitaya germplasm resources for cross-breeding. Pitaya germplasm is diverse, and its genetic ploidy is unknown. The ploidy identification is indispensable to breeding innovation. Forty two accessions of pitaya germplasm were collected and their ploidy was identified by stem tip chromosome preparation technique and flow cytometry. When the current hypotonic time is 2 h, the dissociation time is 1.5 h, the enzymatic hydrolysis time is 1 h, and the post-hypotonic time is 30 min, the cells prepared are intact with good chromosome dispersion and clear background and without overlapping. The ploidy of the pitaya stem tip is stable, and the stem tip is the most reliable material for chromosome determination. The mature stems contain a large number of tetraploid and octaploid cells, and are hence not suitable for ploidy identification. Among the 42 accessions of pitaya germplasm there are 41 accessions diploid, 1 tetraploid and no triploid. The genome size was estimated with accession ‘Jindu No.1’ as a reference. It was found that 15 accessions of pitaya germplasm were very small in genome size with the 1C-value (1C) being ≤1.34 Gb while 27 accessions of pitaya germplasm were small in genome size with the 1C being in the range of 1.35 Gb~3.34 Gb. The identification of the ploidy of 42 accessions of pitaya germplasm might provide some reference for parent selection in pitaya cross breeding.
Effects of different flower forcing methods on flowering and fruit quality of pineapple 'Tainong 16'
2024, 15(3): 315-322.
doi: 10.15886/j.cnki.rdswxb.20230091
Abstract:
Flower forcing is one of the key practices for large-scale and standardized pineapple production. In order to understand the effects of different flower forcing methods on the growth and fruit quality of pineapple, pineapple cultivar 'Tainong 16' was forced to flower by using eight flower forcing methods, and its flowering rate, morphology and fruit quality were determined and analyzed by using correlation analysis. The results showed that the pineapple treated with ethephon at different concentrations was forced to flower at a rate of more than 97%. Under the ethephon treatment in combination of uniconazole or paclobutrazol the plant height decreased, the leaf length and the number of slips increased. Under the ethephon treatment the fruit weight was higher, and the crown was longer, but the peduncle was smaller and easy to break. Fruit quality test showed that the pineapple in the ethephon treatment had higher contents of soluble sugar, soluble solid and vitamin C, and a lower content of total acid. Correlation analysis of 17 characteristics showed the sucker length and the peduncle thickness were highly correlated with yield index, such as fruit weight and longitudinal diameter, whereas the number of slips and the high water content of fruit affected the accumulation of fruit weight and soluble solid. On the whole, ethephon treatment increased the flowering rate, and improved the fruit shape and quality, and can hence be used to promote the production of pineapple 'Tainong 16' in the Pearl River Delta region.
Flower forcing is one of the key practices for large-scale and standardized pineapple production. In order to understand the effects of different flower forcing methods on the growth and fruit quality of pineapple, pineapple cultivar 'Tainong 16' was forced to flower by using eight flower forcing methods, and its flowering rate, morphology and fruit quality were determined and analyzed by using correlation analysis. The results showed that the pineapple treated with ethephon at different concentrations was forced to flower at a rate of more than 97%. Under the ethephon treatment in combination of uniconazole or paclobutrazol the plant height decreased, the leaf length and the number of slips increased. Under the ethephon treatment the fruit weight was higher, and the crown was longer, but the peduncle was smaller and easy to break. Fruit quality test showed that the pineapple in the ethephon treatment had higher contents of soluble sugar, soluble solid and vitamin C, and a lower content of total acid. Correlation analysis of 17 characteristics showed the sucker length and the peduncle thickness were highly correlated with yield index, such as fruit weight and longitudinal diameter, whereas the number of slips and the high water content of fruit affected the accumulation of fruit weight and soluble solid. On the whole, ethephon treatment increased the flowering rate, and improved the fruit shape and quality, and can hence be used to promote the production of pineapple 'Tainong 16' in the Pearl River Delta region.
Effects of flower-forcing treatment at different time on the fruit quality of pineapple ‘Tainong 17’
2024, 15(3): 323-331.
doi: 10.15886/j.cnki.rdswxb.20230124
Abstract:
In order to clarify the effects of flower-forcing treatment at different time on the yield, quality and key endogenous hormones of fruits of pineapple ‘Tainong 17’, flower-forcing treatment was carried out at different time in August and mid-September 2022. Pineapple plants were treated with 2.0% calcium carbide solution at night for 3-5 s at an interval of 1 day in the field. The normal fruit rate, plant dry matter, yield quality and endogenous hormone content of pineapple after forced flowering were determined and their differences were statistically analyzed. The results showed that the maturing time of pineapple fruits in mid-September was about 30 days longer than that in mid-August, and that the proportion of deformed fruits without crowns and multiple crowns in mid-September was 31.33% less than in mid-August. The dry matter accumulation, yield, sugar-acid ratio and soluble protein content of the fruits in the mid-September flower-forcing treatment increased by 6.63%, 25.75%, 23.73% and 50.36%, respectively, and the titratable acid decreased by 14.71%. Compared with the flower-forcing treatment in mid-August, the contents of gibberellin, abscisic acid and trans-zeatin in the fruit of the mid-September treatment were significantly reduced, and the contents of jasmonic acid in the deformed fruit without crowns were significantly increased by 120.93%, and the abscisic acid content in the normal fruits was significantly reduced. In the normal fruits the content of salicylic acid was decreased by 18.18% and 54.81%, respectively, and the content of trans-zeatin was significantly increased by 27.91%. Comprehensive analysis showed that the pineapple ‘Tainong 17’ was higher in fruit quality and yield when forced to flower in mid-September.
In order to clarify the effects of flower-forcing treatment at different time on the yield, quality and key endogenous hormones of fruits of pineapple ‘Tainong 17’, flower-forcing treatment was carried out at different time in August and mid-September 2022. Pineapple plants were treated with 2.0% calcium carbide solution at night for 3-5 s at an interval of 1 day in the field. The normal fruit rate, plant dry matter, yield quality and endogenous hormone content of pineapple after forced flowering were determined and their differences were statistically analyzed. The results showed that the maturing time of pineapple fruits in mid-September was about 30 days longer than that in mid-August, and that the proportion of deformed fruits without crowns and multiple crowns in mid-September was 31.33% less than in mid-August. The dry matter accumulation, yield, sugar-acid ratio and soluble protein content of the fruits in the mid-September flower-forcing treatment increased by 6.63%, 25.75%, 23.73% and 50.36%, respectively, and the titratable acid decreased by 14.71%. Compared with the flower-forcing treatment in mid-August, the contents of gibberellin, abscisic acid and trans-zeatin in the fruit of the mid-September treatment were significantly reduced, and the contents of jasmonic acid in the deformed fruit without crowns were significantly increased by 120.93%, and the abscisic acid content in the normal fruits was significantly reduced. In the normal fruits the content of salicylic acid was decreased by 18.18% and 54.81%, respectively, and the content of trans-zeatin was significantly increased by 27.91%. Comprehensive analysis showed that the pineapple ‘Tainong 17’ was higher in fruit quality and yield when forced to flower in mid-September.
2024, 15(3): 332-336.
doi: 10.15886/j.cnki.rdswxb.20230115
Abstract:
Pissodes castaneus is an important invasive forest pest and a phytosanitary pest in China. The insect pest is native to European countries and has been introduced into Africa and South America. There is no record of the distribution of the insect pest in China, and it was first intercepted at Yangpu Port in Hainan, China in August 2017. P. castaneus mainly infests the cambium and phloem of Pinaceae plants and form pupa chambers under the bark, and it can be spread over long distances through imported timber trade. The adults, larva and pupa of an insect were collected at Yangput Port in August 2017, and their mitochondrial COI genes were amplified by using DNA barcoding and compared with those in GenBank database and BOLD database. The phylogenetic tree of this insect was constructed by using the neighbor-joining algorithm. The results showed that the insect sample and P. castaneus were clustered into the same family and had more than 99% homology. This DNA barcoding method provides a scientific basis for rapid quarantine clearance and detection of invasive forest pests.
Pissodes castaneus is an important invasive forest pest and a phytosanitary pest in China. The insect pest is native to European countries and has been introduced into Africa and South America. There is no record of the distribution of the insect pest in China, and it was first intercepted at Yangpu Port in Hainan, China in August 2017. P. castaneus mainly infests the cambium and phloem of Pinaceae plants and form pupa chambers under the bark, and it can be spread over long distances through imported timber trade. The adults, larva and pupa of an insect were collected at Yangput Port in August 2017, and their mitochondrial COI genes were amplified by using DNA barcoding and compared with those in GenBank database and BOLD database. The phylogenetic tree of this insect was constructed by using the neighbor-joining algorithm. The results showed that the insect sample and P. castaneus were clustered into the same family and had more than 99% homology. This DNA barcoding method provides a scientific basis for rapid quarantine clearance and detection of invasive forest pests.
2024, 15(3): 337-342.
doi: 10.15886/j.cnki.rdswxb.20230053
Abstract:
In order to clarify the harmful symptoms and annual dynamics of coffee leaf rust in dry-hot regions, as well as the impact of altitude gradients on coffee leaf rust and mycoparasitic fungi, the symptoms of coffee leaf rust were observed in the field and its annual dynamics were monitored. An investigation was conducted on the occurrence of coffee leaf rust and mycoparasitic fungi in Arabica coffee plantations at 9 gradients of altitude from 700 to 1 500 m in the dry-hot region of Baoshan, Yunnan. The results show that the coffee leaf rust occurs throughout the year, with the peaks being in December, February and April, and most severe in December in the dry-hot region. The infection of coffee leaf rust is significantly correlated with altitude. The infection of coffee leaf rust at an altitude of 1 500 meters is significantly higher than that at the other eight altitude gradients from 700 m to 1 400 m. Coffee leaf rust occurs all the year round at an altitude of 1 400 m to 1 500 m, and does not occur for more than 2 months at an altitude of 700 m to 1 300 m. The mycoparasitism of coffee leaf rust was found from November to June, and had two peaks, in January with a mycoparasitization rate of (20.19±5.44)% and in March (25.70±5.72)%, respectively. The mycoparasitization increased with the altitude, and the mycoparasitization rates at 1 400 m and 1 500 m were significantly higher than those at the other seven altitude gradients ranging from 800 m to 1 300 m. All these results indicate that altitude has a significant impact on coffee leaf rust, and that the occurrence of mycoparasites and coffee leaf rust is significantly delayed in the dry-hot region. In the areas of high altitude, the mycoparasitization rate of coffee leaf rust exceeds 20%, and the mycoparasitic fungi shows promise as a biocontrol agent of the coffee leaf rust.
In order to clarify the harmful symptoms and annual dynamics of coffee leaf rust in dry-hot regions, as well as the impact of altitude gradients on coffee leaf rust and mycoparasitic fungi, the symptoms of coffee leaf rust were observed in the field and its annual dynamics were monitored. An investigation was conducted on the occurrence of coffee leaf rust and mycoparasitic fungi in Arabica coffee plantations at 9 gradients of altitude from 700 to 1 500 m in the dry-hot region of Baoshan, Yunnan. The results show that the coffee leaf rust occurs throughout the year, with the peaks being in December, February and April, and most severe in December in the dry-hot region. The infection of coffee leaf rust is significantly correlated with altitude. The infection of coffee leaf rust at an altitude of 1 500 meters is significantly higher than that at the other eight altitude gradients from 700 m to 1 400 m. Coffee leaf rust occurs all the year round at an altitude of 1 400 m to 1 500 m, and does not occur for more than 2 months at an altitude of 700 m to 1 300 m. The mycoparasitism of coffee leaf rust was found from November to June, and had two peaks, in January with a mycoparasitization rate of (20.19±5.44)% and in March (25.70±5.72)%, respectively. The mycoparasitization increased with the altitude, and the mycoparasitization rates at 1 400 m and 1 500 m were significantly higher than those at the other seven altitude gradients ranging from 800 m to 1 300 m. All these results indicate that altitude has a significant impact on coffee leaf rust, and that the occurrence of mycoparasites and coffee leaf rust is significantly delayed in the dry-hot region. In the areas of high altitude, the mycoparasitization rate of coffee leaf rust exceeds 20%, and the mycoparasitic fungi shows promise as a biocontrol agent of the coffee leaf rust.
2024, 15(3): 343-348.
doi: 10.15886/j.cnki.rdswxb.20230085
Abstract:
Natural enemy insects are important biological factors in pest control, which can not only decrease population of pests through direct predation, but also change the growth, development and reproduction of pests through non-consumptive effects, indirectly affecting the fitness of pests. Winter melons and vegetables are important crops for high-efficient development of tropical agriculture in Hainan, and an aphid, Aphis gossypii, was considered as an important pest causing great damage to cucumbers and other melons crops. For comprehensive assessment of the impact of natural enemies on aphid populations, the life table method was utilized to investigate the non-consumptive effects of a local predatory natural enemy, Cheilomenes sexmaculata, on aphids, A. gossypii. The results revealed that the non-consumptive effect of C. sexmaculata on A. gossypii varied depending on the duration of treatment. After a 24-hour treatment, the aphid offspring showed a significant decrease in the longevity, reproduction duration, total reproduction, and R0. The research findings indicate that the non-consumptive effects of C. sexmaculata significantly altered the growth, development, reproduction, and other population life table parameters of the aphids. The findings will contribute to a more thorough assessment of ladybeetles' capacity to regulate aphid populations, thus offering novel approaches for ecologically-friendly aphid management (especially resistant aphids).
Natural enemy insects are important biological factors in pest control, which can not only decrease population of pests through direct predation, but also change the growth, development and reproduction of pests through non-consumptive effects, indirectly affecting the fitness of pests. Winter melons and vegetables are important crops for high-efficient development of tropical agriculture in Hainan, and an aphid, Aphis gossypii, was considered as an important pest causing great damage to cucumbers and other melons crops. For comprehensive assessment of the impact of natural enemies on aphid populations, the life table method was utilized to investigate the non-consumptive effects of a local predatory natural enemy, Cheilomenes sexmaculata, on aphids, A. gossypii. The results revealed that the non-consumptive effect of C. sexmaculata on A. gossypii varied depending on the duration of treatment. After a 24-hour treatment, the aphid offspring showed a significant decrease in the longevity, reproduction duration, total reproduction, and R0. The research findings indicate that the non-consumptive effects of C. sexmaculata significantly altered the growth, development, reproduction, and other population life table parameters of the aphids. The findings will contribute to a more thorough assessment of ladybeetles' capacity to regulate aphid populations, thus offering novel approaches for ecologically-friendly aphid management (especially resistant aphids).
2024, 15(3): 349-353.
doi: 10.15886/j.cnki.rdswxb.20230014
Abstract:
The species diversity of the Conidae is extremely high, and has been getting extensive attention for the research of conotoxin (CTx). In China waters, conids are distributed mainly in Taiwan and the South China Sea, and there are more than 160 species so far, accounting for almost 17% of the global conids species. The common Conidae species in the South China Sea, Conus marmoreus Linnaeus, 1758 is similar to Conus bandanus Hwass in Bruguière, 1792 in shape and there is some overlap in their distribution range in China seas, so they are easy to be confused. Our comparative study between the two species is conducted on the Conus specimens deposited in Marine Biodiversity Collections of South China Sea (SCSMBC, Guangzhou). The taxonomic confusion of the two species is clarified on shell morphology and habitat: C. marmoreus has week shoulder tubercles or even absent, and both the size and the pattern of the nearly triangular white spots on the body-whorl surface are relatively uniform, without dark brown spiral bands; while C. bandanus has more pronounced spire tubercles and a less regular pattern with two distinct dark color bands. Ecological differences also favour separation at the species level: C. bandanus usually lives in deeper water. In China, C. bandanus has been found in Taiwan before; the speciesmens examinated in this work were collected from Hainan, Xisha Islands and Nansha Islands, which further improves the geographical distribution information of C. bandanus in China Seas and can also provide a reliable basis for the accurate identification of CTx-derived organisms.
The species diversity of the Conidae is extremely high, and has been getting extensive attention for the research of conotoxin (CTx). In China waters, conids are distributed mainly in Taiwan and the South China Sea, and there are more than 160 species so far, accounting for almost 17% of the global conids species. The common Conidae species in the South China Sea, Conus marmoreus Linnaeus, 1758 is similar to Conus bandanus Hwass in Bruguière, 1792 in shape and there is some overlap in their distribution range in China seas, so they are easy to be confused. Our comparative study between the two species is conducted on the Conus specimens deposited in Marine Biodiversity Collections of South China Sea (SCSMBC, Guangzhou). The taxonomic confusion of the two species is clarified on shell morphology and habitat: C. marmoreus has week shoulder tubercles or even absent, and both the size and the pattern of the nearly triangular white spots on the body-whorl surface are relatively uniform, without dark brown spiral bands; while C. bandanus has more pronounced spire tubercles and a less regular pattern with two distinct dark color bands. Ecological differences also favour separation at the species level: C. bandanus usually lives in deeper water. In China, C. bandanus has been found in Taiwan before; the speciesmens examinated in this work were collected from Hainan, Xisha Islands and Nansha Islands, which further improves the geographical distribution information of C. bandanus in China Seas and can also provide a reliable basis for the accurate identification of CTx-derived organisms.
2024, 15(3): 354-360.
doi: 10.15886/j.cnki.rdswxb.20230086
Abstract:
As one of the key techniques in fry fish rearing, feeding management affects survival, growth and development of the fry. An attempt was made to analyze the effect of the feeding management on the growth and body color change of the fry of white angelfish. The fry of white angelfish (Pterophyllum scalare) were fed with three combinations of foods, including commercial microcapsule feed (M group), microcapsule feed with Artemia sp. nauplii (MA group) and fishmeal feed with Artemia sp. nauplii (AF group). The survival, growth and body color of the white angelfish fry fed with different food combinations were analyzed and compared. The results showed that the survival rates in all the groups were more than 82%, where the MA group was significantly higher than the M and AF groups (P < 0.05). The body weight, length, weight gain rate and specific growth rate were significantly higher in the MA group than in the AF group (P < 0.05). The regularity was observed in the body color of different body position in each group with the lightness(L*) being in the order of “abdomen > operculum > lower back”, the red tonality (a*) being in the order of “operculum > abdomen > lower back” and the yellow hue (b*) in the order of “lower back > abdomen > operculum”. Feeding Artemia sp. nauplii could affect the yellow hue (b*) of P. scalare fry during rearing. The proper use of Artemia sp. nauplii to feed the white angelfish at the right stage of fish rearing helps to improve the growth performance and enhance the ornamental character of the fish body color.
As one of the key techniques in fry fish rearing, feeding management affects survival, growth and development of the fry. An attempt was made to analyze the effect of the feeding management on the growth and body color change of the fry of white angelfish. The fry of white angelfish (Pterophyllum scalare) were fed with three combinations of foods, including commercial microcapsule feed (M group), microcapsule feed with Artemia sp. nauplii (MA group) and fishmeal feed with Artemia sp. nauplii (AF group). The survival, growth and body color of the white angelfish fry fed with different food combinations were analyzed and compared. The results showed that the survival rates in all the groups were more than 82%, where the MA group was significantly higher than the M and AF groups (P < 0.05). The body weight, length, weight gain rate and specific growth rate were significantly higher in the MA group than in the AF group (P < 0.05). The regularity was observed in the body color of different body position in each group with the lightness(L*) being in the order of “abdomen > operculum > lower back”, the red tonality (a*) being in the order of “operculum > abdomen > lower back” and the yellow hue (b*) in the order of “lower back > abdomen > operculum”. Feeding Artemia sp. nauplii could affect the yellow hue (b*) of P. scalare fry during rearing. The proper use of Artemia sp. nauplii to feed the white angelfish at the right stage of fish rearing helps to improve the growth performance and enhance the ornamental character of the fish body color.
2024, 15(3): 361-367.
doi: 10.15886/j.cnki.rdswxb.20230102
Abstract:
Betaphycus gelatinae was cut into sections of different lengths from different explants and cultured at different temperatures to explore the suitable conditions for its tissue culture to determine the effects of different explants (stem tip, main branch and trunk), section lengths (5 mm, 10 mm and 15 mm) and culture temperatures (21 ℃, 24 ℃, 27 ℃, 30 ℃ and 33 ℃) on bud emergence and growth of the explants of B. gelatinae. The results showed that the survival rate and bud emergence rate of different explants and section lengths were all up to 100%. The number of buds in different explants was in the order of the trunk > the main branch > the stem tip. The stem tip mainly grew elongate, while the main branch and trunk were mainly expanded and formed buds. The buds were formed on the upper cut, not on the lower cut, showing obvious polarity. The number of the buds in the sections of different lengths was in the order of the sections 15 mm long > the sections 10 mm long > the sections 5 mm long. The number of individual buds in the sections 15 mm long was 5.90 ± 0.67 in the stem tip, 10.16 ± 1.14 in the main branch and 11.90 ± 0.88 in the trunk. The highest budding density was in the sections 5 mm long. The suitable growth temperature for tissue culture of B. gelatinae ranged from 21℃ to 27 ℃, under which the survival rate and bud emergence rate were both 100%, and the number of buds increased with the temperature. The survival rate and bud emergenc rate of the sections were decreased when the temperature was above 27 ℃. For optimal tissue culture B. gelatinae was cultured at 27 ℃ with the trunk sections 15 mm long as explants.
Betaphycus gelatinae was cut into sections of different lengths from different explants and cultured at different temperatures to explore the suitable conditions for its tissue culture to determine the effects of different explants (stem tip, main branch and trunk), section lengths (5 mm, 10 mm and 15 mm) and culture temperatures (21 ℃, 24 ℃, 27 ℃, 30 ℃ and 33 ℃) on bud emergence and growth of the explants of B. gelatinae. The results showed that the survival rate and bud emergence rate of different explants and section lengths were all up to 100%. The number of buds in different explants was in the order of the trunk > the main branch > the stem tip. The stem tip mainly grew elongate, while the main branch and trunk were mainly expanded and formed buds. The buds were formed on the upper cut, not on the lower cut, showing obvious polarity. The number of the buds in the sections of different lengths was in the order of the sections 15 mm long > the sections 10 mm long > the sections 5 mm long. The number of individual buds in the sections 15 mm long was 5.90 ± 0.67 in the stem tip, 10.16 ± 1.14 in the main branch and 11.90 ± 0.88 in the trunk. The highest budding density was in the sections 5 mm long. The suitable growth temperature for tissue culture of B. gelatinae ranged from 21℃ to 27 ℃, under which the survival rate and bud emergence rate were both 100%, and the number of buds increased with the temperature. The survival rate and bud emergenc rate of the sections were decreased when the temperature was above 27 ℃. For optimal tissue culture B. gelatinae was cultured at 27 ℃ with the trunk sections 15 mm long as explants.
2024, 15(3): 368-372.
doi: 10.15886/j.cnki.rdswxb.20230016
Abstract:
Onchidium verruculatum, a characteristic resource in the South China Sea, was extracted and isolated by using a variety of separation and purification methods, including silica gel, Sephadex LH-20, thin layer chromatography and semi-prepared HPLC. The structures of the compounds were identified by combining their biochemical characteristics, NMR data analysis and reference comparison. Twelve compounds were isolated from Onchidium verruculatum, and their structures were identified as Cyclo-(L-Pro-L-Val) ( 1 ), Cyclo-(Pro-Ile) ( 2 ), Cyclo-(L-Pro-D-Leu) ( 3 ), Tyramine ( 4 ), Cyclo-(L-Pro-L-Phe) ( 5 ), 2-Piperidone ( 6 ), Cyclo-(L-Ala-L-Pro) ( 7 ), uracil ribonucleoside ( 8 ), uracil ( 9 ), thymine ( 10 ), 2'-methoxyuracil nucleoside ( 11 ), thymidine ( 12 ). Compounds ( 1-6, 11 ) were isolated for the first time from Onchidium verruculatum.
Onchidium verruculatum, a characteristic resource in the South China Sea, was extracted and isolated by using a variety of separation and purification methods, including silica gel, Sephadex LH-20, thin layer chromatography and semi-prepared HPLC. The structures of the compounds were identified by combining their biochemical characteristics, NMR data analysis and reference comparison. Twelve compounds were isolated from Onchidium verruculatum, and their structures were identified as Cyclo-(L-Pro-L-Val) ( 1 ), Cyclo-(Pro-Ile) ( 2 ), Cyclo-(L-Pro-D-Leu) ( 3 ), Tyramine ( 4 ), Cyclo-(L-Pro-L-Phe) ( 5 ), 2-Piperidone ( 6 ), Cyclo-(L-Ala-L-Pro) ( 7 ), uracil ribonucleoside ( 8 ), uracil ( 9 ), thymine ( 10 ), 2'-methoxyuracil nucleoside ( 11 ), thymidine ( 12 ). Compounds ( 1-6, 11 ) were isolated for the first time from Onchidium verruculatum.
Supervisor: Department of education of Hainan Province
Sponsor: Hainan University
ISSN 1674-7054
CN 46-1078/S
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LI Cheng, ZHANG Yu, LUO An, JU Shuang, FU Ying, LUO Sulan - 2 ZHANG Zhuandan, XIAO Zhengpan, WU Xinli, SUN Yan, LUO Ying, WU Hao, WEI Shuangshuang, PEI Yechun, WANG Dayong
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