Current Issue
2025 Vol.16 NO.2
2025,
16(2):
163-171.
doi: 10.15886/j.cnki.rdswxb.20240056
Abstract
Abstract:
Cassava is an important tropical food crop with high light efficiency and drought tolerance. Stomata is the gateway through which water and air exchange between plant leaves and the external environment. Stomata density directly affect the drought resistance of plants. However, the physiological mechanism of stomata in the formation of drought tolerance in cassava is not clear. In order to analyze the physiological regulation mechanism of cassava under drought stress, the stomatal density of 93 cassava cultivars was statistically analyzed, the changes of stomatal density of different cassava cultivars under drought stress were compared, and the physiological and biochemical indexes of their leaves were measured to analyze the relationship between stomatal density and physiological indexes of different cassava cultivars and their drought resistance. The results showed that stomatal density of cassava cultivars under drought stress was not consistent. Overall, there was a weak negative correlation between stomatal density and drought resistance（correlation coefficient was -0.15）. The soluble sugar content and transpiration rate decreased significantly in 6 cassava cultivars（3 with low stomatal density and 3 with high stomatal density） under drought stress, but the change was not very consistent in both the high and low stomatal density cultivars. It was hence concluded that drought had a greater impact on cassava growth, and that cassava might respond to drought stress quickly through the synthesis of osmoregulatory substances and antioxidant enzymes, which further affect the differentiation and development of stomata.
Cassava is an important tropical food crop with high light efficiency and drought tolerance. Stomata is the gateway through which water and air exchange between plant leaves and the external environment. Stomata density directly affect the drought resistance of plants. However, the physiological mechanism of stomata in the formation of drought tolerance in cassava is not clear. In order to analyze the physiological regulation mechanism of cassava under drought stress, the stomatal density of 93 cassava cultivars was statistically analyzed, the changes of stomatal density of different cassava cultivars under drought stress were compared, and the physiological and biochemical indexes of their leaves were measured to analyze the relationship between stomatal density and physiological indexes of different cassava cultivars and their drought resistance. The results showed that stomatal density of cassava cultivars under drought stress was not consistent. Overall, there was a weak negative correlation between stomatal density and drought resistance（correlation coefficient was -0.15）. The soluble sugar content and transpiration rate decreased significantly in 6 cassava cultivars（3 with low stomatal density and 3 with high stomatal density） under drought stress, but the change was not very consistent in both the high and low stomatal density cultivars. It was hence concluded that drought had a greater impact on cassava growth, and that cassava might respond to drought stress quickly through the synthesis of osmoregulatory substances and antioxidant enzymes, which further affect the differentiation and development of stomata.
2025,
16(2):
172-180.
doi: 10.15886/j.cnki.rdswxb.20240051
Abstract:
In order to analyze the law of starch accumulation in root tubers of cassava cultivars in different harvesting periods, 4 cassava cultivars ‘SC205’, ‘SC8’, ‘SC9’ and ‘SC6068’ were determined in terms of fresh weight and biomass of root tubers and ratio of amylose and amylopectin in starch after 6 to 10 months of planting,and the underlying mechanism was analyzed. The results showed that there were significant differences in fresh tuber weight in different cassava harvesting periods. There were significant differences in amylose ratio in different harvesting periods in the same cultivar, and the amylose ratio increased in the later growth period of cassava. The ribulose diphosphate carboxylase（Rubisco） content of high-yielding cultivars SC205 and SC8 was generally lower than that of low-yielding cultivars ‘SC6068’ and ‘SC9’ after 7 to 10 months of planting. At 7 to 10 months after planting, the content of PSⅡ oxygen releasing complex gradually increased in SC8, was relatively stable in SC205, and gradually decreased in SC9 and SC6068 at 9 to 10 months after planting. In October cassava production was the highest, and cultivars ‘SC205’, ‘SC9’ and ‘SC6068’ were the highest in the content of PSⅡoxygen releasing complex. The cultivars ‘SC205’, ‘SC8’,‘SC9’ and ‘SC6068’ showed an increasing trend in the content of sucrose phosphate synthetase（SPS） after October, whereas the activity of β-amylase increased from September to October, and decreased from November to December. The protein content of ascorbate peroxidase（APX） was relatively stable in ‘SC6068’ from September to December. The cultivars ‘SC205’, ‘SC8’ and ‘SC9’ showed an increasing trend in APX content from September to December. In conclusion, there were significant differences in yield and starch composition among different cultivars, the mechanism of which was closely related to leaf photosynthesis, antioxidant activity and root starch synthetase activity.
In order to analyze the law of starch accumulation in root tubers of cassava cultivars in different harvesting periods, 4 cassava cultivars ‘SC205’, ‘SC8’, ‘SC9’ and ‘SC6068’ were determined in terms of fresh weight and biomass of root tubers and ratio of amylose and amylopectin in starch after 6 to 10 months of planting,and the underlying mechanism was analyzed. The results showed that there were significant differences in fresh tuber weight in different cassava harvesting periods. There were significant differences in amylose ratio in different harvesting periods in the same cultivar, and the amylose ratio increased in the later growth period of cassava. The ribulose diphosphate carboxylase（Rubisco） content of high-yielding cultivars SC205 and SC8 was generally lower than that of low-yielding cultivars ‘SC6068’ and ‘SC9’ after 7 to 10 months of planting. At 7 to 10 months after planting, the content of PSⅡ oxygen releasing complex gradually increased in SC8, was relatively stable in SC205, and gradually decreased in SC9 and SC6068 at 9 to 10 months after planting. In October cassava production was the highest, and cultivars ‘SC205’, ‘SC9’ and ‘SC6068’ were the highest in the content of PSⅡoxygen releasing complex. The cultivars ‘SC205’, ‘SC8’,‘SC9’ and ‘SC6068’ showed an increasing trend in the content of sucrose phosphate synthetase（SPS） after October, whereas the activity of β-amylase increased from September to October, and decreased from November to December. The protein content of ascorbate peroxidase（APX） was relatively stable in ‘SC6068’ from September to December. The cultivars ‘SC205’, ‘SC8’ and ‘SC9’ showed an increasing trend in APX content from September to December. In conclusion, there were significant differences in yield and starch composition among different cultivars, the mechanism of which was closely related to leaf photosynthesis, antioxidant activity and root starch synthetase activity.
2025,
16(2):
181-187.
doi: 10.15886/j.cnki.rdswxb.20240066
Abstract:
Polysaccharide（MSP-2） was extracted from Millettia speciosa Champ by hydroalcohol precipitation to analyze its chemical structure. The protein was removed by enzyme digestion and Sevag method, and then further purified by using anion-exchange column chromatography and gel filtration column chromatography to obtain MSP-2 fractions. The structure of the polysaccharide was analyzed in detail by using four analytical methods,including high performance anion exchange chromatography（HPAEC-PAD）, gel permeation（GPC-RIDMALLS）, Fourier infrared spectroscopy（FT-IR）, and nuclear magnetic resonance（ NMR）. The results showed that MSP-2 is a homogeneous neutral polysaccharide composed of glucopyranose with an average molecular weight（Mw） of 12.5 kDa and that its main backbone consists of T-α-D-Glcp,（1,4）-α-D-Glcp and（1,4,6）-α-DGlcp. Toxicity evaluation by MTT assay showed that MSP-2 was not toxic to RAW264.7 cells when its concentration was lower than 400 μg·mL-1.
Polysaccharide（MSP-2） was extracted from Millettia speciosa Champ by hydroalcohol precipitation to analyze its chemical structure. The protein was removed by enzyme digestion and Sevag method, and then further purified by using anion-exchange column chromatography and gel filtration column chromatography to obtain MSP-2 fractions. The structure of the polysaccharide was analyzed in detail by using four analytical methods,including high performance anion exchange chromatography（HPAEC-PAD）, gel permeation（GPC-RIDMALLS）, Fourier infrared spectroscopy（FT-IR）, and nuclear magnetic resonance（ NMR）. The results showed that MSP-2 is a homogeneous neutral polysaccharide composed of glucopyranose with an average molecular weight（Mw） of 12.5 kDa and that its main backbone consists of T-α-D-Glcp,（1,4）-α-D-Glcp and（1,4,6）-α-DGlcp. Toxicity evaluation by MTT assay showed that MSP-2 was not toxic to RAW264.7 cells when its concentration was lower than 400 μg·mL-1.
2025,
16(2):
188-195.
doi: 10.15886/j.cnki.rdswxb.20240061
Abstract:
An attempt was made to analyze the chemical constituents of Liquidambaris Fructus, the infructescenses of Liquidambaris formosa Hance, for better development and utilization of Liquidambaris Fructus.The constituents were isolated from different polar solvent extracts of Liquidambaris Fructus and purified by column chromatography, Sephadex LH-20, and semi-preparative high-performance liquid chromatography, and the structures of the compounds purified were identified by employing spectroscopy combined with literature. A total of 17 compounds were isolated from the extracts, including 10 triterpenoids（ 1～10 ）, 1 sterol compound（ 12 ）,2 phenolic acids（ 11, 13 ）, and 3 aromatic esters（ 14, 15, 17 ）. These compounds were identified as oleanolic acid（ 1 ）, ursolic acid（ 2 ）, betulinic acid（ 3 ）, methyl 3-oxoolean-12-en-28-oate（ 4 ）, 3-oxo-11,13（18）-oleanadien-28-oic acid（ 5 ）, 3α-hydroxy-lup-20（29）-ene-28-oic acid（ 6 ）,3-oxooleanolic acid（ 7 ）, 3,30-dioxo-lup-20（29）-en-28-oic acid（ 8 ）, 3-epimaslinic acid（ 9 ）, 3, 11-dioxoolean-12-en-28-oic acid（ 10 ）, gallic acid（ 11 ）, β-sitosterol（ 12 ）, 3, 3′-dimethoxy ellagic acid-4′-O-β-D-primeveroside（ 13 ）, Dipentyl phthalate（ 14 ）, cinnamyl cinnamate（ 15 ）, cisdodeca-1,3-diene（ 16 ）, bis（2-ethyloctyl） phthalate（ 17 ）. Compounds 4, 8, 10, 13, 14, 16 and 17 were isolated for the first time from the genus Liquidambaris and compounds 4, 8, 13, and 16 were also isolated from the genus Liquidambar for the first time, which provides references for the in-depth development of these compounds.
An attempt was made to analyze the chemical constituents of Liquidambaris Fructus, the infructescenses of Liquidambaris formosa Hance, for better development and utilization of Liquidambaris Fructus.The constituents were isolated from different polar solvent extracts of Liquidambaris Fructus and purified by column chromatography, Sephadex LH-20, and semi-preparative high-performance liquid chromatography, and the structures of the compounds purified were identified by employing spectroscopy combined with literature. A total of 17 compounds were isolated from the extracts, including 10 triterpenoids（ 1～10 ）, 1 sterol compound（ 12 ）,2 phenolic acids（ 11, 13 ）, and 3 aromatic esters（ 14, 15, 17 ）. These compounds were identified as oleanolic acid（ 1 ）, ursolic acid（ 2 ）, betulinic acid（ 3 ）, methyl 3-oxoolean-12-en-28-oate（ 4 ）, 3-oxo-11,13（18）-oleanadien-28-oic acid（ 5 ）, 3α-hydroxy-lup-20（29）-ene-28-oic acid（ 6 ）,3-oxooleanolic acid（ 7 ）, 3,30-dioxo-lup-20（29）-en-28-oic acid（ 8 ）, 3-epimaslinic acid（ 9 ）, 3, 11-dioxoolean-12-en-28-oic acid（ 10 ）, gallic acid（ 11 ）, β-sitosterol（ 12 ）, 3, 3′-dimethoxy ellagic acid-4′-O-β-D-primeveroside（ 13 ）, Dipentyl phthalate（ 14 ）, cinnamyl cinnamate（ 15 ）, cisdodeca-1,3-diene（ 16 ）, bis（2-ethyloctyl） phthalate（ 17 ）. Compounds 4, 8, 10, 13, 14, 16 and 17 were isolated for the first time from the genus Liquidambaris and compounds 4, 8, 13, and 16 were also isolated from the genus Liquidambar for the first time, which provides references for the in-depth development of these compounds.
2025,
16(2):
196-205.
doi: 10.15886/j.cnki.rdswxb.20240005
Abstract:
Embryonic development is a continuous and dynamic process. The division of various stages is conducive to identifying the characteristic developmental states of the embryo at different durations of time, and a detailed description of the developmental status of the melon fly（Zeugodacus cucurbitae） at each stage is beneficial for a more comprehensive understanding of the internal development of the melon fly embryo. This holds significant applied value in insect prediction and genetic prevention and control. In this context an attempt was made to conduct a thorough observation and analysis of the embryonic development process of the melon fly,and the internal states of the melon fly embryo during different developmental stages were demonstrated by employing microscopic photography. Through this experimental operation, the embryos at different developmental stages can be accurately screened. The experimental results revealed that the melon fly embryo undergoes a series of internal activities from the time of laying, starting from the initial cytoplasmic contraction within the egg to the appearance of anterior and posterior poles, followed by nuclear migration and the emergence and migration of polar cells. Subsequently, dorsal folds and the invagination of the mouth and head occur, while the yolk sac begins to undergo constant changes and intestinal coils start to emerge. Around 24 hours, the larva begins vigorous movements within the embryo, and by the 30th hour, the tracheal bundles become filled with air. The larva hatches by tearing the yolk membrane at the micropyle with its mouth hook. Additionally, cell division,differentiation, and tissue formation during the embryonic development of the melon fly are closely related to different stages of mitosis. This study provides an important reference for understanding the molecular mechanisms of melon fly embryonic development and offers new insights for genetic prevention and control research. Currently, most prevention and control methods for the melon fly target the larval and adult stages, but the embryonic stage, due to its low motility and concentration, poses less difficulty in control. Therefore, there is an urgent and necessary need to develop novel targeted control measures based on the characteristics of the melon fly embryos at each stage. This study lays a foundation for genetic prevention and control of the melon fly at the embryonic stage and provides a new direction for future in-depth research on embryonic development and genetic prevention and control of the melon fly.
Embryonic development is a continuous and dynamic process. The division of various stages is conducive to identifying the characteristic developmental states of the embryo at different durations of time, and a detailed description of the developmental status of the melon fly（Zeugodacus cucurbitae） at each stage is beneficial for a more comprehensive understanding of the internal development of the melon fly embryo. This holds significant applied value in insect prediction and genetic prevention and control. In this context an attempt was made to conduct a thorough observation and analysis of the embryonic development process of the melon fly,and the internal states of the melon fly embryo during different developmental stages were demonstrated by employing microscopic photography. Through this experimental operation, the embryos at different developmental stages can be accurately screened. The experimental results revealed that the melon fly embryo undergoes a series of internal activities from the time of laying, starting from the initial cytoplasmic contraction within the egg to the appearance of anterior and posterior poles, followed by nuclear migration and the emergence and migration of polar cells. Subsequently, dorsal folds and the invagination of the mouth and head occur, while the yolk sac begins to undergo constant changes and intestinal coils start to emerge. Around 24 hours, the larva begins vigorous movements within the embryo, and by the 30th hour, the tracheal bundles become filled with air. The larva hatches by tearing the yolk membrane at the micropyle with its mouth hook. Additionally, cell division,differentiation, and tissue formation during the embryonic development of the melon fly are closely related to different stages of mitosis. This study provides an important reference for understanding the molecular mechanisms of melon fly embryonic development and offers new insights for genetic prevention and control research. Currently, most prevention and control methods for the melon fly target the larval and adult stages, but the embryonic stage, due to its low motility and concentration, poses less difficulty in control. Therefore, there is an urgent and necessary need to develop novel targeted control measures based on the characteristics of the melon fly embryos at each stage. This study lays a foundation for genetic prevention and control of the melon fly at the embryonic stage and provides a new direction for future in-depth research on embryonic development and genetic prevention and control of the melon fly.
2025,
16(2):
206-217.
doi: 10.15886/j.cnki.rdswxb.20240020
Abstract:
Previous studies in our laboratory have showed that a new compound N-arylpyridine-4-one class [1-（4-（tert-butyl）phenyl）-3-hydroxy-2-methylpyridin-4（1H）-one,HAINU-19] had better fungicidal activity against Botrytis cinerea.In order to further clarify the control effect of the compound on gray mold of tomato,the toxicity of mixtures of HAINU-19 and azoxystrobin against the multi-resistant strain of B.cinerea was evaluated.The toxicity of the mixtures of HAINU-19 and azoxystrobin to B.cinerea at different ratios was determined by mycelial growth rate method to select the optimal synergistic ratio,and the synergistic mechanism of the mixtures was assessed by using the inhibition rate of spore germination,the morphology of mycelium and dry mycelia mass,as well as soluble protein content,reducing sugar content,malondialdehyde content and antioxidant enzyme activity.The results showed that the EC50 values of HAINU-19 and azoxystrobin against the strain of B.cinerea were7.926 μg·mL-1 and 23.898 μg·mL-1,respectively,with the synergistic coefficient of WHAINU-19:WAzoxystrobin=4:3being 2.034,indicating the mixture at this ratio had the most significant synergies.After treatment with WHAINU-19:WAzoxytrobin=4:3 mixture,spore germination and mycelia growth were inhibited,and the cell membrane permeability was increased.Furthermore,the soluble protein and reducing sugar content were decreased,while the malondialdehyde content and antioxidant enzyme activity increased.This indicated that the synergistic combination mainly improved cell membrane permeability and electrolyte extravasation by increasing the degree of cell membrane damage,which resulted in the damage of mycelial growth.Meanwhile,the protein synthesis and glucose metabolism were inhibited,and the accumulation of intracellular reactive oxygen species was stressed,which inhibited the normal growth of B.cinerea.
Previous studies in our laboratory have showed that a new compound N-arylpyridine-4-one class [1-（4-（tert-butyl）phenyl）-3-hydroxy-2-methylpyridin-4（1H）-one,HAINU-19] had better fungicidal activity against Botrytis cinerea.In order to further clarify the control effect of the compound on gray mold of tomato,the toxicity of mixtures of HAINU-19 and azoxystrobin against the multi-resistant strain of B.cinerea was evaluated.The toxicity of the mixtures of HAINU-19 and azoxystrobin to B.cinerea at different ratios was determined by mycelial growth rate method to select the optimal synergistic ratio,and the synergistic mechanism of the mixtures was assessed by using the inhibition rate of spore germination,the morphology of mycelium and dry mycelia mass,as well as soluble protein content,reducing sugar content,malondialdehyde content and antioxidant enzyme activity.The results showed that the EC50 values of HAINU-19 and azoxystrobin against the strain of B.cinerea were7.926 μg·mL-1 and 23.898 μg·mL-1,respectively,with the synergistic coefficient of WHAINU-19:WAzoxystrobin=4:3being 2.034,indicating the mixture at this ratio had the most significant synergies.After treatment with WHAINU-19:WAzoxytrobin=4:3 mixture,spore germination and mycelia growth were inhibited,and the cell membrane permeability was increased.Furthermore,the soluble protein and reducing sugar content were decreased,while the malondialdehyde content and antioxidant enzyme activity increased.This indicated that the synergistic combination mainly improved cell membrane permeability and electrolyte extravasation by increasing the degree of cell membrane damage,which resulted in the damage of mycelial growth.Meanwhile,the protein synthesis and glucose metabolism were inhibited,and the accumulation of intracellular reactive oxygen species was stressed,which inhibited the normal growth of B.cinerea.
2025,
16(2):
218-226.
doi: 10.15886/j.cnki.rdswxb.20240045
Abstract:
An attempt was made to explore the influence of Eucalyptus spp. dieback disease on soil bacteria under Eucalyptus spp. forests and its impact on the ecological mechanism of soil bacteria, providing a theoretical basis for revealing the pathogenesis of Eucalyptus spp. dieback disease and developing ecological prevention and control techniques for this disease. The soil bacterial DNA of Eucalyptus spp. forests affected and unaffected by dieback disease were sequenced using 16S rRNA. Data were statistically analyzed using SPSS 20.0, Microsoft Excel 2019, and R4.3.2 software, and images were processed using Adobe Illustrator 2021. A total of 2 537bacterial ASVs were detected in the soil of affected forests, and 2 477 ASVs were detected in unaffected soil.There was no significant difference in alpha diversity of bacteria between the two forest soils. The dominant phyla in both affected and unaffected（healthy） forest soils were Proteobacteria, Chloroflexi, and Actinobacteria, and the dominant genera were Acidothermus, norank＿f＿norank＿o＿Elsterales, and norank f＿Xanthobacteraceae.Significant differences in bacteria between the two forest soils were observed at the phylum level for Bacteroidota and Dependentiae, and at the genus level for norank＿f＿norank＿o＿Acidobacteriales, norank＿f＿norank＿o＿norank＿c＿AD3 and norank＿f＿norank＿o＿B12-WMSP1. There were more complex connections among microbial communities in the healthy forest soils compared to the affected ones. Eucalyptus spp. dieback disease does not significantly alter the diversity of soil bacteria under forests, and the soil still retains certain ecological regulation capabilities. However, differences between some bacterial communities suggest that Eucalyptus spp. dieback disease may potentially impact soil microbiota under Eucalyptus spp. forests.
An attempt was made to explore the influence of Eucalyptus spp. dieback disease on soil bacteria under Eucalyptus spp. forests and its impact on the ecological mechanism of soil bacteria, providing a theoretical basis for revealing the pathogenesis of Eucalyptus spp. dieback disease and developing ecological prevention and control techniques for this disease. The soil bacterial DNA of Eucalyptus spp. forests affected and unaffected by dieback disease were sequenced using 16S rRNA. Data were statistically analyzed using SPSS 20.0, Microsoft Excel 2019, and R4.3.2 software, and images were processed using Adobe Illustrator 2021. A total of 2 537bacterial ASVs were detected in the soil of affected forests, and 2 477 ASVs were detected in unaffected soil.There was no significant difference in alpha diversity of bacteria between the two forest soils. The dominant phyla in both affected and unaffected（healthy） forest soils were Proteobacteria, Chloroflexi, and Actinobacteria, and the dominant genera were Acidothermus, norank＿f＿norank＿o＿Elsterales, and norank f＿Xanthobacteraceae.Significant differences in bacteria between the two forest soils were observed at the phylum level for Bacteroidota and Dependentiae, and at the genus level for norank＿f＿norank＿o＿Acidobacteriales, norank＿f＿norank＿o＿norank＿c＿AD3 and norank＿f＿norank＿o＿B12-WMSP1. There were more complex connections among microbial communities in the healthy forest soils compared to the affected ones. Eucalyptus spp. dieback disease does not significantly alter the diversity of soil bacteria under forests, and the soil still retains certain ecological regulation capabilities. However, differences between some bacterial communities suggest that Eucalyptus spp. dieback disease may potentially impact soil microbiota under Eucalyptus spp. forests.
2025,
16(2):
227-235.
doi: 10.15886/j.cnki.rdswxb.20240102
Abstract:
An attempt was made to compare and analyze the composition and structure of soil fungal communities under Eucalyptus spp. stands healthy or infected with Calonectria leaf blight based on Illumina high-throughput sequencing so as to reveal the interactions between the pathogen Calonectria and other fungi, which might provide theoretical support for the development of biocontrol agents. A total of 2 817 fungal ASVs（Amplicon Sequence Variants） were annotated from 12 tested samples, classified into 12 phyla, 421 genera, and 614 species.There was no significant difference in alpha diversity of soil fungi between the diseased and healthy Eucalyptus spp. stands, with dominant phyla being consistent. Among the top five most abundant genera, the genera with the highest abundance were unclassified＿k＿Fungi followed by Saitozyma, while the other three genera differed between the two groups. Differential analysis of fungal abundances and correlation analysis with the pathogen Calonectria showed that Thelephora ranked fifth in abundance in healthy stands and had significantly higher levels in healthy stand soils compared to the diseased stands, suggesting it could be an antagonist of Calonectria leaf blight. Temitomyces and Xyladictyochaeta both had significantly higher abundances in the diseased stands than in the healthy ones（P ＜ 0.05） and could serve as potential biocontrol agents. Calonectria had a negative correlation with Ophiocordyceps, which is commonly used as a biocontrol agent and could also be a candidate for controlling Calonectria leaf blight. The findings revealed that the Calonectria leaf blight pathogen Calonectria comprised a relatively small proportion of the fungal community in Eucalyptus spp. soils but still had the pathogenicity to cause disease in Eucalyptus spp. These results provided theoretical support for the development of biocontrol agents and antagonists against Calonectria leaf blight in Eucalyptus spp.
An attempt was made to compare and analyze the composition and structure of soil fungal communities under Eucalyptus spp. stands healthy or infected with Calonectria leaf blight based on Illumina high-throughput sequencing so as to reveal the interactions between the pathogen Calonectria and other fungi, which might provide theoretical support for the development of biocontrol agents. A total of 2 817 fungal ASVs（Amplicon Sequence Variants） were annotated from 12 tested samples, classified into 12 phyla, 421 genera, and 614 species.There was no significant difference in alpha diversity of soil fungi between the diseased and healthy Eucalyptus spp. stands, with dominant phyla being consistent. Among the top five most abundant genera, the genera with the highest abundance were unclassified＿k＿Fungi followed by Saitozyma, while the other three genera differed between the two groups. Differential analysis of fungal abundances and correlation analysis with the pathogen Calonectria showed that Thelephora ranked fifth in abundance in healthy stands and had significantly higher levels in healthy stand soils compared to the diseased stands, suggesting it could be an antagonist of Calonectria leaf blight. Temitomyces and Xyladictyochaeta both had significantly higher abundances in the diseased stands than in the healthy ones（P ＜ 0.05） and could serve as potential biocontrol agents. Calonectria had a negative correlation with Ophiocordyceps, which is commonly used as a biocontrol agent and could also be a candidate for controlling Calonectria leaf blight. The findings revealed that the Calonectria leaf blight pathogen Calonectria comprised a relatively small proportion of the fungal community in Eucalyptus spp. soils but still had the pathogenicity to cause disease in Eucalyptus spp. These results provided theoretical support for the development of biocontrol agents and antagonists against Calonectria leaf blight in Eucalyptus spp.
2025,
16(2):
236-242.
doi: 10.15886/j.cnki.rdswxb.20240129
Abstract:
Chemical spraying is he fast and effective way to control Spodoptera frugiperda infesting maize in the field, but the chemical solutions are hard to spray evenly on the leaves, which reduces the contact of the solutions by the larvae of S. frugiperda and hence the effectiveness of the control of S. frugiperda at the seedling stage in the field. In this context maize seeds were coated with chlorfenapyr to evaluate the effect of chlorfenapyr on the seed germination rate, seed germination potential and seedling emergence rate as well as the control effect of S.frugiperda in maize at the seedling stage. The results showed that there was no significant adverse effect of chlorfenapyr-coated seed treatment on seed germination, germination potential, and seedling emergence in the pot experiment. The mortality of S. frugiperda larvae fed with maize leaves from the seed coating treatment with 1 g·L-1 chlorfenapy for 7 d was 96.67%, significantly better than that of the blank control, but not significantly different from that of the chlorantraniliprole treatment. In the field experiment, the seed coating treatment with 1 g·L-1 chlorfenapyr had a lower infestation rate of maize plants（7.67%） and higher control rate（98.33%） of S.frugiperda at 14 d, which were significantly better than those of the chlorantraniliprole treatment. All these results showed that chlorfenapyr had a good control of S. frugiperda at the seedling stage of maize through seed coating treatment, which provides a new method for the subsequent seed coating treatment to control S. frugiperda.
Chemical spraying is he fast and effective way to control Spodoptera frugiperda infesting maize in the field, but the chemical solutions are hard to spray evenly on the leaves, which reduces the contact of the solutions by the larvae of S. frugiperda and hence the effectiveness of the control of S. frugiperda at the seedling stage in the field. In this context maize seeds were coated with chlorfenapyr to evaluate the effect of chlorfenapyr on the seed germination rate, seed germination potential and seedling emergence rate as well as the control effect of S.frugiperda in maize at the seedling stage. The results showed that there was no significant adverse effect of chlorfenapyr-coated seed treatment on seed germination, germination potential, and seedling emergence in the pot experiment. The mortality of S. frugiperda larvae fed with maize leaves from the seed coating treatment with 1 g·L-1 chlorfenapy for 7 d was 96.67%, significantly better than that of the blank control, but not significantly different from that of the chlorantraniliprole treatment. In the field experiment, the seed coating treatment with 1 g·L-1 chlorfenapyr had a lower infestation rate of maize plants（7.67%） and higher control rate（98.33%） of S.frugiperda at 14 d, which were significantly better than those of the chlorantraniliprole treatment. All these results showed that chlorfenapyr had a good control of S. frugiperda at the seedling stage of maize through seed coating treatment, which provides a new method for the subsequent seed coating treatment to control S. frugiperda.
2025,
16(2):
243-253.
doi: 10.15886/j.cnki.rdswxb.20240098
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Abstract:
An attempt was made to investigate the naturally occurring, difficult-to-separate combinations of mycorrhizal fungi and endophytic bacteria found in the mycorrhizae of Dendrobium nobile Lindl. Three groups of artificially cultivable and separable natural combinations of mycorrhizal fungi and endophytic bacteria were isolated,screened, and identified. Through co-cultivation experiments and functional assessments, the symbiotic relationships and mechanisms among these combinations were analyzed. The results showed that G2 and G8 are symbiotic combinations of Bacillus and Fusarium solani, while G17 is a combination of Bacillus and Diaporthe phaseolorum.There is an antagonistic relationship between the G2 and G17 combinations, leading to an increased total growth,whereas the G8 combination exhibits no antagonistic relationship, with mutual promotion between the two. The fungi in the G2 and G17 combinations possess strong cellulolytic abilities, with clear zone diameters of 27.62 mm and 21.52 mm,respectively, while the bacteria exhibit nitrogen-fixing abilities of 1.69 μg·mL-1 and 1.68 μg·mL-1, respectively. The strong cellulolytic and nitrogen-fixing abilities contribute to the antagonistic relationship between the G2 and G17combinations. In the G8 combination, the fungal solution contains the lowest hydrolyzed phosphorus, while the bacteria have the highest phosphorus-solubilizing ability, reaching 39.07 mg·kg-1, indicating a complementary functional relationship. Therefore, natural symbiotic combinations exhibit various forms of symbiotic relationships, including complementarity, promotion, and inhibition, and there is a correlation between function and symbiotic relationship.
An attempt was made to investigate the naturally occurring, difficult-to-separate combinations of mycorrhizal fungi and endophytic bacteria found in the mycorrhizae of Dendrobium nobile Lindl. Three groups of artificially cultivable and separable natural combinations of mycorrhizal fungi and endophytic bacteria were isolated,screened, and identified. Through co-cultivation experiments and functional assessments, the symbiotic relationships and mechanisms among these combinations were analyzed. The results showed that G2 and G8 are symbiotic combinations of Bacillus and Fusarium solani, while G17 is a combination of Bacillus and Diaporthe phaseolorum.There is an antagonistic relationship between the G2 and G17 combinations, leading to an increased total growth,whereas the G8 combination exhibits no antagonistic relationship, with mutual promotion between the two. The fungi in the G2 and G17 combinations possess strong cellulolytic abilities, with clear zone diameters of 27.62 mm and 21.52 mm,respectively, while the bacteria exhibit nitrogen-fixing abilities of 1.69 μg·mL-1 and 1.68 μg·mL-1, respectively. The strong cellulolytic and nitrogen-fixing abilities contribute to the antagonistic relationship between the G2 and G17combinations. In the G8 combination, the fungal solution contains the lowest hydrolyzed phosphorus, while the bacteria have the highest phosphorus-solubilizing ability, reaching 39.07 mg·kg-1, indicating a complementary functional relationship. Therefore, natural symbiotic combinations exhibit various forms of symbiotic relationships, including complementarity, promotion, and inhibition, and there is a correlation between function and symbiotic relationship.
2025,
16(2):
254-259.
doi: 10.15886/j.cnki.rdswxb.20240010
Abstract:
During the continuing investigation of the antibacterial metabolites from endophytic Aspergillus sp. HU0206,six compounds were isolated from the fermented culture of this fungus by column chromatography and high-performance liquid preparation. These compounds were elucidated as four methylcyclohexanones: ampelomin A（ 1 ）, 7-hydroxylampelomin A（ 2 ）, 7-O-ethylampelomin A（ 3 ）, 2,3-dihydroxyl-7-O-ethylampelomin A（ 4 ） and two methylphenols:2-（methoxymethyl）-1,4-benzenediol（ 5 ） and 3-chlorogentisyl alcohol（ 6 ） on the basis of NMR and ESI-MS analyses.Compounds 2-4 are new compounds. At the dose of 40 μg, compounds 1, 2 and 6 showed obvious antibacterial effects on Xanthomonas oryzae with inhibition zones of 4.0 mm. Compound 6 also exhibited inhibitory activities against Staphylococcus aureus, methicillin-resistant S. aureus, Pectobacterium atroseptica and Ralstonia solanacearum. However,compounds 3-5 showed no inhibitory activity against X. oryzae and compounds 1-5 were inactive against the other four strains mentioned above. The biosynthesis pathway of the metabolites from Aspergillus sp. HU0206 was also discussed.
During the continuing investigation of the antibacterial metabolites from endophytic Aspergillus sp. HU0206,six compounds were isolated from the fermented culture of this fungus by column chromatography and high-performance liquid preparation. These compounds were elucidated as four methylcyclohexanones: ampelomin A（ 1 ）, 7-hydroxylampelomin A（ 2 ）, 7-O-ethylampelomin A（ 3 ）, 2,3-dihydroxyl-7-O-ethylampelomin A（ 4 ） and two methylphenols:2-（methoxymethyl）-1,4-benzenediol（ 5 ） and 3-chlorogentisyl alcohol（ 6 ） on the basis of NMR and ESI-MS analyses.Compounds 2-4 are new compounds. At the dose of 40 μg, compounds 1, 2 and 6 showed obvious antibacterial effects on Xanthomonas oryzae with inhibition zones of 4.0 mm. Compound 6 also exhibited inhibitory activities against Staphylococcus aureus, methicillin-resistant S. aureus, Pectobacterium atroseptica and Ralstonia solanacearum. However,compounds 3-5 showed no inhibitory activity against X. oryzae and compounds 1-5 were inactive against the other four strains mentioned above. The biosynthesis pathway of the metabolites from Aspergillus sp. HU0206 was also discussed.
2025,
16(2):
260-269.
doi: 10.15886/j.cnki.rdswxb.20240043
Abstract:
Flowering phenology is one of the most important life cycle traits of plants and one of the most sensitive indicators of the impact of climate change on ecosystems. Previous studies on flowering phenology were.focused on temperate regions, with limited research on tropical and subtropical regions. It remains to be studied whether there are different patterns of plant phenology in the transitional zone between subtropical and warm temperate regions. In this context an attempt was made to analyze the effects of plant phylogenetic and climatic factors on the flowering patterns of plants in the Qinling Mountains region. A total of 5 084 flowering data from 1 830 species and local meteorological data from 2000 to 2020 were collected from the Chinese Field Herbarium Museum to determine the impact of these two factors on flowering phenology. The results showed that the peak of plant flowering occurred in July, the flowering pattern being mostly single peak. There are significant differences in flowering phenology among plants of different families, and there is no significant difference in phenology among plants of different genera within the same family, indicating that species with similar genetic relationships have more similar flowering times. The phenological pattern of flowering in the Qinling Mountains is influenced by the coupling mechanism of precipitation and temperature, with precipitation being the main climatic factor driving the flowering of plant communities in the Qinling Mountains. All these results showed that in the transitional zone between subtropical and temperate regions, both plant phylogenetic relationships and climatic factors may affect the phenological patterns of plant flowering.
Flowering phenology is one of the most important life cycle traits of plants and one of the most sensitive indicators of the impact of climate change on ecosystems. Previous studies on flowering phenology were.focused on temperate regions, with limited research on tropical and subtropical regions. It remains to be studied whether there are different patterns of plant phenology in the transitional zone between subtropical and warm temperate regions. In this context an attempt was made to analyze the effects of plant phylogenetic and climatic factors on the flowering patterns of plants in the Qinling Mountains region. A total of 5 084 flowering data from 1 830 species and local meteorological data from 2000 to 2020 were collected from the Chinese Field Herbarium Museum to determine the impact of these two factors on flowering phenology. The results showed that the peak of plant flowering occurred in July, the flowering pattern being mostly single peak. There are significant differences in flowering phenology among plants of different families, and there is no significant difference in phenology among plants of different genera within the same family, indicating that species with similar genetic relationships have more similar flowering times. The phenological pattern of flowering in the Qinling Mountains is influenced by the coupling mechanism of precipitation and temperature, with precipitation being the main climatic factor driving the flowering of plant communities in the Qinling Mountains. All these results showed that in the transitional zone between subtropical and temperate regions, both plant phylogenetic relationships and climatic factors may affect the phenological patterns of plant flowering.
2025,
16(2):
270-280.
doi: 10.15886/j.cnki.rdswxb.20240118
Abstract:
Soil microorganisms play an important role in agricultural ecosystem functions. However, there is still a limited understanding of the spatial distribution patterns of soil microbial communities in agroforestry systems,especially for abundant and rare taxa. Kapok-rice agroforestry system, a traditional agroforestry system, has long been practiced in tropical areas. In this context an analysis and comparison were made of the spatial distribution patterns of abundant and rare bacterial and fungal communities along distance gradients to Kapok and their relationships with soil factors in such agroforestry system located in Changjiang County, Hainan Province. The results showed that the richness of rare bacteria was significantly higher near Kapok, while the Shannon index of abundant bacteria and fungi were significantly lower near Kapok（P＜0.05）. Compositions of abundant and rare bacterial and fungal communities varied significantly with distance gradients to Kapok（ANOSIM: P=0.0001）.The α-diversity of abundant bacteria was significantly negatively correlated with available potassium, while the α-diversity of rare bacteria was significantly positively correlated with total potassium and soil organic matters. The α-diversity of abundant fungi was not significantly correlated with any soil factor, while the α-diversity of rare fungi was significantly positively correlated with soil available nitrogen and phosphorus and soil organic matters.Soil available nutrients were the dominant driving factors of the variations of abundant bacterial and fungal community structures, while both soil available nutrients and soil organic matter were the driving factors affecting the variations of rare bacterial and fungal community structures. Among these soil factors, the soil available potassium was the most important driver of the distribution patterns of both abundant and rare microorganisms.This study reveals the effect of Kapok on distribution characteristics of different soil microbial taxa in the rice field and their driving factors in the Kapok-rice agroforestry system, which might provide theoretical support for the application of the Kapok-rice agroforestry system in agricultural sustainable development.
Soil microorganisms play an important role in agricultural ecosystem functions. However, there is still a limited understanding of the spatial distribution patterns of soil microbial communities in agroforestry systems,especially for abundant and rare taxa. Kapok-rice agroforestry system, a traditional agroforestry system, has long been practiced in tropical areas. In this context an analysis and comparison were made of the spatial distribution patterns of abundant and rare bacterial and fungal communities along distance gradients to Kapok and their relationships with soil factors in such agroforestry system located in Changjiang County, Hainan Province. The results showed that the richness of rare bacteria was significantly higher near Kapok, while the Shannon index of abundant bacteria and fungi were significantly lower near Kapok（P＜0.05）. Compositions of abundant and rare bacterial and fungal communities varied significantly with distance gradients to Kapok（ANOSIM: P=0.0001）.The α-diversity of abundant bacteria was significantly negatively correlated with available potassium, while the α-diversity of rare bacteria was significantly positively correlated with total potassium and soil organic matters. The α-diversity of abundant fungi was not significantly correlated with any soil factor, while the α-diversity of rare fungi was significantly positively correlated with soil available nitrogen and phosphorus and soil organic matters.Soil available nutrients were the dominant driving factors of the variations of abundant bacterial and fungal community structures, while both soil available nutrients and soil organic matter were the driving factors affecting the variations of rare bacterial and fungal community structures. Among these soil factors, the soil available potassium was the most important driver of the distribution patterns of both abundant and rare microorganisms.This study reveals the effect of Kapok on distribution characteristics of different soil microbial taxa in the rice field and their driving factors in the Kapok-rice agroforestry system, which might provide theoretical support for the application of the Kapok-rice agroforestry system in agricultural sustainable development.
2025,
16(2):
281-289.
doi: 10.15886/j.cnki.rdswxb.20240094
Abstract:
Currently, there is a lack of emphasis on the ornamental value evaluation and germplasm collection of Coffea liberica in China, making it difficult to systematically select outstanding C. liberica clones, which also restricts the commercial cultivation and application of superior selections of C. liberica in landscapeing.. In Hainan Island 128 individual seedling trees of C. liberica germplasm were selected for survey and statistical analysis of their ornamental traits Four evaluation criteria such as C1 leaf, C2 fruit, C3 flower and C4 others, and 14 evaluation factors were selected by using the analytic hierarchy process（AHP） to establish an evaluation system for the ornamental traits of C. liberica in Hainan Island. Meanwhile, the ornamental grades of 128 Coffea liberica individual seedling trees were evaluated to provide reference for landscape application and selection of elite ornamental individuals. The results show that in the overall ranking value C2（0.534） fruit has the highest weight, followed by C1（0.240） flower, which indicates that the ornamental traits of flowers and fruits have significant impact on the ornamental evaluation of C. liberica resources. Among the 14 evaluation indicators, P4mature fruit color（28%）, P6 fruiting period（17.8%）, and P10 number of flower branches（13.8%） are the main indicators affecting the ornamental value of C. liberica. Based on the comprehensive index score, 63 superior C.liberica individual plants were selected, which can be an important resource for landscape application. In conclusion, the AHP method can be effectively used to conduct a comprehensive evaluation of C. liberica germplasm, and select the most suitable individual plants for landscape application in Hainan, laying a foundation for their widespread promotion in gardens.
Currently, there is a lack of emphasis on the ornamental value evaluation and germplasm collection of Coffea liberica in China, making it difficult to systematically select outstanding C. liberica clones, which also restricts the commercial cultivation and application of superior selections of C. liberica in landscapeing.. In Hainan Island 128 individual seedling trees of C. liberica germplasm were selected for survey and statistical analysis of their ornamental traits Four evaluation criteria such as C1 leaf, C2 fruit, C3 flower and C4 others, and 14 evaluation factors were selected by using the analytic hierarchy process（AHP） to establish an evaluation system for the ornamental traits of C. liberica in Hainan Island. Meanwhile, the ornamental grades of 128 Coffea liberica individual seedling trees were evaluated to provide reference for landscape application and selection of elite ornamental individuals. The results show that in the overall ranking value C2（0.534） fruit has the highest weight, followed by C1（0.240） flower, which indicates that the ornamental traits of flowers and fruits have significant impact on the ornamental evaluation of C. liberica resources. Among the 14 evaluation indicators, P4mature fruit color（28%）, P6 fruiting period（17.8%）, and P10 number of flower branches（13.8%） are the main indicators affecting the ornamental value of C. liberica. Based on the comprehensive index score, 63 superior C.liberica individual plants were selected, which can be an important resource for landscape application. In conclusion, the AHP method can be effectively used to conduct a comprehensive evaluation of C. liberica germplasm, and select the most suitable individual plants for landscape application in Hainan, laying a foundation for their widespread promotion in gardens.
2025,
16(2):
290-303.
doi: 10.15886/j.cnki.rdswxb.20240041
Abstract:
An attempt was made to analyze the chemical constituents of the volatile oil from the stems and leaves of Piper sarmentosum Roxb. from different habitats in Hainan, which is of guiding significance for screening of germplasm resources and product development. The volatile oil was extracted from the stems and leaves of Piper sarmentosum Roxb. by ultrasonic-assisted solvent extraction. The components of the volatile oil were analyzed by gas chromatography-mass spectrometry（GC-MS）, and the relative contents of its chemical components were determined by peak area normalization method. Ninety six compounds were identified from volatile oil samples from 9 habitats in Hainan. The volatile oil components of the stems and leaves of Piper sarmentosum Roxb. from different habitats in Hainan were comprehensively analyzed through principal component analysis. The results showed that the volatile oil components of the 9 samples from different habitats can be divided into two categories with P1（origin: Chengxi Town, Longhua District, Haikou City, Hainan Province）, P2（origin: Baodaoxincun Village, Danzhou City, Hainan Province）, P3（origin: Jianfengling, Ledong Li Autonomous County, Hainan Province）, P4（origin: Diaoluoshan, Lingshui Li Autonomous County, Hainan Province） and P5（origin: Jiaxi Village, Dongfang City, Hainan Province） being in category one, and P6（origin: Zhongyuan Town, qionghai city,Hainan Province）, P7（origin: Team 6 of Zhongjian Farm, Poxin Town, tunchang, Hainan Province）, P8（origin:Damao International Aquilaria Valley, Sanya, Hainan Province） and P9（origin: Maogan Township, Baoting Li and Miao Autonomous County, Hainan Province） being in category two. To sum up, the GC-MS analysis results of the volatile oil from nine different habitats in Hainan were systematically analyze by innovatively using the principal component analysis and other methods. Combined with the existing reports, it was found that the volatile oil components of the same species were affected by many factors such as provenance differences, geographical conditions, extraction methods and climate environment, which was consistent with the results of this study. Some new volatile components, such as Xanthium sibiricum, 1-ethylbutyl hydroperoxide, 4-methyl-2-pentanol, etc.were also found, which has certain reference value for further supplementing and refining the list of the volatile oil components of P. sarmentosum Roxb.. The results show that there are differences in chemical composition of volatile oil and species from nine different habitats in Hainan. But at the same time, there are some similarities.There are 22 volatile oil components with high content in 9 different producing areas（Table 4）. In addition, the volatile oil of P. sarmentosum Roxb. mainly contains aromatics, fatty acids, alkaloids, terpenoids and other compounds, among which the content of aromatic chemical components is high and the content of fatty acids is the lowest. After comprehensive evaluation and screening, compared with the other eight producing areas, the volatile oil from Jianfengling（P3）, Ledong Li Autonomous County, Hainan Province is the most abundant in chemical components, and its germplasm resources are superior. This research result is of great significance in the screening of germplasm resources and product development in the future.
An attempt was made to analyze the chemical constituents of the volatile oil from the stems and leaves of Piper sarmentosum Roxb. from different habitats in Hainan, which is of guiding significance for screening of germplasm resources and product development. The volatile oil was extracted from the stems and leaves of Piper sarmentosum Roxb. by ultrasonic-assisted solvent extraction. The components of the volatile oil were analyzed by gas chromatography-mass spectrometry（GC-MS）, and the relative contents of its chemical components were determined by peak area normalization method. Ninety six compounds were identified from volatile oil samples from 9 habitats in Hainan. The volatile oil components of the stems and leaves of Piper sarmentosum Roxb. from different habitats in Hainan were comprehensively analyzed through principal component analysis. The results showed that the volatile oil components of the 9 samples from different habitats can be divided into two categories with P1（origin: Chengxi Town, Longhua District, Haikou City, Hainan Province）, P2（origin: Baodaoxincun Village, Danzhou City, Hainan Province）, P3（origin: Jianfengling, Ledong Li Autonomous County, Hainan Province）, P4（origin: Diaoluoshan, Lingshui Li Autonomous County, Hainan Province） and P5（origin: Jiaxi Village, Dongfang City, Hainan Province） being in category one, and P6（origin: Zhongyuan Town, qionghai city,Hainan Province）, P7（origin: Team 6 of Zhongjian Farm, Poxin Town, tunchang, Hainan Province）, P8（origin:Damao International Aquilaria Valley, Sanya, Hainan Province） and P9（origin: Maogan Township, Baoting Li and Miao Autonomous County, Hainan Province） being in category two. To sum up, the GC-MS analysis results of the volatile oil from nine different habitats in Hainan were systematically analyze by innovatively using the principal component analysis and other methods. Combined with the existing reports, it was found that the volatile oil components of the same species were affected by many factors such as provenance differences, geographical conditions, extraction methods and climate environment, which was consistent with the results of this study. Some new volatile components, such as Xanthium sibiricum, 1-ethylbutyl hydroperoxide, 4-methyl-2-pentanol, etc.were also found, which has certain reference value for further supplementing and refining the list of the volatile oil components of P. sarmentosum Roxb.. The results show that there are differences in chemical composition of volatile oil and species from nine different habitats in Hainan. But at the same time, there are some similarities.There are 22 volatile oil components with high content in 9 different producing areas（Table 4）. In addition, the volatile oil of P. sarmentosum Roxb. mainly contains aromatics, fatty acids, alkaloids, terpenoids and other compounds, among which the content of aromatic chemical components is high and the content of fatty acids is the lowest. After comprehensive evaluation and screening, compared with the other eight producing areas, the volatile oil from Jianfengling（P3）, Ledong Li Autonomous County, Hainan Province is the most abundant in chemical components, and its germplasm resources are superior. This research result is of great significance in the screening of germplasm resources and product development in the future.
2025,
16(2):
304-311.
doi: 10.15886/j.cnki.rdswxb.20240124
Abstract:
Four culture density groups (D1:1.16 kg·m-3;D2:2.32 kg·m-3;D3:3.48 kg·m-3;D4:4.62 kg·m-3) were set up to culture Archocentrus nigrofasciatus var.× Mikrogeophagus ramirezi,and the differences of growth rate,antioxidant enzyme activity and spawning quantity among different groups were compared to reveal the effects of culture density on the growth and reproduction of A.nigrofasciatus var.× M.ramirezi.The results showed that when the culture density did not exceed 2.32 kg·m-3,A.nigrofasciatus var.× M.ramirezi was normal in mortality rate（13.06±4.59）%,number of eggs laid （133±45.00）,average initial weight of eggs （0.001 8±0.000 4） g,body mass（3.73±1.22） g,final body length （3.63±0.55） cm,specific growth rate （0.005 7±0.000 6）%,average weight gain rate （1.47±0.12）%and hatching rate （80.23±0.09）%and not high in the activities of malondialdehyde （MDA）,alanine aminotransferase （ALT）,total superoxide dismutase （SOD） and catalase （CAT）（P＜0.05）.The peak concentrations of NH4+-N and NO2--N in aquaculture water increased significantly （P＜0.05） with the culture density.All these results show that under the condition of closed recirculating water culture,the culture of A.nigrofasciatus var.× M.ramirezi at a density higher than 2.32 kg·m-3 will lead to an increase in peak concentrations of NH4+-N and NO2--N and antioxidant enzyme activities,which will inhibit the healthy growth and reproduction of A.nigrofasciatus var.×M.ramirezi.The optimum breeding density of A.nigrofasciatus var.× M.ramirezi is 2.32 kg·m-3.
Four culture density groups (D1:1.16 kg·m-3;D2:2.32 kg·m-3;D3:3.48 kg·m-3;D4:4.62 kg·m-3) were set up to culture Archocentrus nigrofasciatus var.× Mikrogeophagus ramirezi,and the differences of growth rate,antioxidant enzyme activity and spawning quantity among different groups were compared to reveal the effects of culture density on the growth and reproduction of A.nigrofasciatus var.× M.ramirezi.The results showed that when the culture density did not exceed 2.32 kg·m-3,A.nigrofasciatus var.× M.ramirezi was normal in mortality rate（13.06±4.59）%,number of eggs laid （133±45.00）,average initial weight of eggs （0.001 8±0.000 4） g,body mass（3.73±1.22） g,final body length （3.63±0.55） cm,specific growth rate （0.005 7±0.000 6）%,average weight gain rate （1.47±0.12）%and hatching rate （80.23±0.09）%and not high in the activities of malondialdehyde （MDA）,alanine aminotransferase （ALT）,total superoxide dismutase （SOD） and catalase （CAT）（P＜0.05）.The peak concentrations of NH4+-N and NO2--N in aquaculture water increased significantly （P＜0.05） with the culture density.All these results show that under the condition of closed recirculating water culture,the culture of A.nigrofasciatus var.× M.ramirezi at a density higher than 2.32 kg·m-3 will lead to an increase in peak concentrations of NH4+-N and NO2--N and antioxidant enzyme activities,which will inhibit the healthy growth and reproduction of A.nigrofasciatus var.×M.ramirezi.The optimum breeding density of A.nigrofasciatus var.× M.ramirezi is 2.32 kg·m-3.
2025,
16(2):
312-326.
doi: 10.15886/j.cnki.rdswxb.20240028
Abstract:
In order to identify the characteristics of plankton community structure and evaluate the water quality of tropical marine ranches in the sea area around Wuzhizhou Island based on the biodiversity index, sampling surveys of phytoplankton and environment factors were carried out in June（summer） and November（autumn）2020, and January（winter）, April（spring） and August（summer） 2021. A total of 217 phytoplankton species were identified in 5 phyla with the maximum species richness of diatoms（116 species） and dinoflagellates（97 species）.Arthropods（118 species） were main in 187 species of zooplankton in 8 phyla. The annual average abundances of phytoplankton and zooplankton were 2.53×106 cell·m-3 and 1.83×103 ind·m-3, respectively. The Shannon-Wiener index（H’）, Margalef index（J） and Pielou index（d） of phytoplankton and zooplankton communities were higher in spring, which indicated the ecosystem was more stable in this season. Hierarchical cluster analysis showed that seasonal variations in the compositions of phytoplankton and zooplankton communities were significant but no substantial difference was observed in different marine ranches, indicating artificial reefs started to work in the marine ranches. The frequent tourism in the northern vicinity of the island had to some extent affected the structure of plankton communities and played a latent negative role in water quality. The water quality evaluation based on the biodiversity index showed that the quality was of oligopollution or pollution free. All these results will provide useful data for evaluation of the ecosystem of marine ranching and the construction and development of the marine ranches around Wuzhizhou Island.
In order to identify the characteristics of plankton community structure and evaluate the water quality of tropical marine ranches in the sea area around Wuzhizhou Island based on the biodiversity index, sampling surveys of phytoplankton and environment factors were carried out in June（summer） and November（autumn）2020, and January（winter）, April（spring） and August（summer） 2021. A total of 217 phytoplankton species were identified in 5 phyla with the maximum species richness of diatoms（116 species） and dinoflagellates（97 species）.Arthropods（118 species） were main in 187 species of zooplankton in 8 phyla. The annual average abundances of phytoplankton and zooplankton were 2.53×106 cell·m-3 and 1.83×103 ind·m-3, respectively. The Shannon-Wiener index（H’）, Margalef index（J） and Pielou index（d） of phytoplankton and zooplankton communities were higher in spring, which indicated the ecosystem was more stable in this season. Hierarchical cluster analysis showed that seasonal variations in the compositions of phytoplankton and zooplankton communities were significant but no substantial difference was observed in different marine ranches, indicating artificial reefs started to work in the marine ranches. The frequent tourism in the northern vicinity of the island had to some extent affected the structure of plankton communities and played a latent negative role in water quality. The water quality evaluation based on the biodiversity index showed that the quality was of oligopollution or pollution free. All these results will provide useful data for evaluation of the ecosystem of marine ranching and the construction and development of the marine ranches around Wuzhizhou Island.
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