2017 Vol. 8, No. 3
2017, 8(3): 241-247.
doi: 10.15886/j.cnki.rdswxb.2017.03.001
Abstract
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Abstract:
Two strains of the genera Lactobacillus of bacteria,Weissella confusa（LAB041） and Lactobacillus plantarum（LAB1036）,isolated from Dross vinegar in Hainan were used to feed healthy larvae（20 days old） of Pacific white shrimp,Litopenaeus vannamei,to observe their effect on growth performance,non-specific immunity and stress resistance of the Pacific white shrimp.The results showed that the survival rate,final length,weight gain percentage and specific growth rate of the pacific white shrimp treated after 8 weeks were significantly higher in the LAB041 group than in the control group（P＜0.05）.There was significantly lower feed conversion ratio in the LAB041 and LAB1036 groups than in the control group（P＜0.05）.The results of non-specific immunity parameters showed that the Pacific white shrimp fed the diets containing W.confusa（LAB041） had significantly higher activity of total antioxidant capacity（T-AOC） and acid phosphatase（ACP） than the control group（P＜0.05）,and significantly lower superoxide dismutase（SOD） activity than the control group（P＜0.05）.The results of stress resistance experiment show that feeding the diets containing LAB1036 improved the tolerance of the Pacific white shrimp to nitrite and low level of salinity.However a single factor analysis of variance showed that there was no significant difference in mortality between the groups（P＞0.05）.Feeding the diets containing LAB041 and LAB1036 significantly reduced the tolerance of shrimp to high salinity（P＜0.05）.
Two strains of the genera Lactobacillus of bacteria,Weissella confusa（LAB041） and Lactobacillus plantarum（LAB1036）,isolated from Dross vinegar in Hainan were used to feed healthy larvae（20 days old） of Pacific white shrimp,Litopenaeus vannamei,to observe their effect on growth performance,non-specific immunity and stress resistance of the Pacific white shrimp.The results showed that the survival rate,final length,weight gain percentage and specific growth rate of the pacific white shrimp treated after 8 weeks were significantly higher in the LAB041 group than in the control group（P＜0.05）.There was significantly lower feed conversion ratio in the LAB041 and LAB1036 groups than in the control group（P＜0.05）.The results of non-specific immunity parameters showed that the Pacific white shrimp fed the diets containing W.confusa（LAB041） had significantly higher activity of total antioxidant capacity（T-AOC） and acid phosphatase（ACP） than the control group（P＜0.05）,and significantly lower superoxide dismutase（SOD） activity than the control group（P＜0.05）.The results of stress resistance experiment show that feeding the diets containing LAB1036 improved the tolerance of the Pacific white shrimp to nitrite and low level of salinity.However a single factor analysis of variance showed that there was no significant difference in mortality between the groups（P＞0.05）.Feeding the diets containing LAB041 and LAB1036 significantly reduced the tolerance of shrimp to high salinity（P＜0.05）.
2017, 8(3): 248-254.
doi: 10.15886/j.cnki.rdswxb.2017.03.002
Abstract:
A strain SCS-KFD03 of Aspergillus sp.was isolated from Sipunculus nudus collected from Haikou Bay,and fermented.Active constituents were isolated and purified from the fermentation broth and hyphae of the strain SCS-KFD03 by using various chromatographic techniques,including Silica gel,Sephadex LH-20 column and HPLC chromatography.Seven compounds（1-7） were extracted from the secondary metabolites of the strain SCS-KFD03 and identified as 3β,5α-dihydroxy-（22 E,24 R）-ergosta-7,22-dien-6-one（1）,3β,4α-dihydroxy-26-methoxyer gosta-7,24（28）-dien-6-one（2）,（22 E,24 R）-ergosta-5,7,22-trien-3β-ol（3）,leporin B（4）,astellolide G（5）,astellolide B（6） and astellolide A（7）.The bio-activity evaluation of these compounds showed that compounds 2,3,5 and 6 had a certain antioxidant activity towards DPPH free radical.The compound 2 also exhibited a weak inhibitory activity against acetyl cholinesterase,and the compound 4 had a higher inhibitory activity against α-glucosidase than the positive control acarbose.
A strain SCS-KFD03 of Aspergillus sp.was isolated from Sipunculus nudus collected from Haikou Bay,and fermented.Active constituents were isolated and purified from the fermentation broth and hyphae of the strain SCS-KFD03 by using various chromatographic techniques,including Silica gel,Sephadex LH-20 column and HPLC chromatography.Seven compounds（1-7） were extracted from the secondary metabolites of the strain SCS-KFD03 and identified as 3β,5α-dihydroxy-（22 E,24 R）-ergosta-7,22-dien-6-one（1）,3β,4α-dihydroxy-26-methoxyer gosta-7,24（28）-dien-6-one（2）,（22 E,24 R）-ergosta-5,7,22-trien-3β-ol（3）,leporin B（4）,astellolide G（5）,astellolide B（6） and astellolide A（7）.The bio-activity evaluation of these compounds showed that compounds 2,3,5 and 6 had a certain antioxidant activity towards DPPH free radical.The compound 2 also exhibited a weak inhibitory activity against acetyl cholinesterase,and the compound 4 had a higher inhibitory activity against α-glucosidase than the positive control acarbose.
2017, 8(3): 255-266.
doi: 10.15886/j.cnki.rdswxb.2017.03.003
Abstract:
Vibrio alginolyticus is one of the most important pathogens for seafood-borne infection in South China.Extracellular polysaccharides（EPSs） are a type of polysaccharides produced by bacteria with a complex structure,and affect the pathogenicity and environmental adaptability of pathogens.Genomic analysis shows that about four gene clusters related to the synthesis of exopolysaccharides exist in V.alginolyticus ZJ-51.In this study,bioinformatic analysis and verification experiment were used to find out the potential functions of two gene clusters of them,i.e.CPS1357 gene cluster and CPS4543 gene cluster.The results show that the gene cluster CPS4543 encoded three homologous proteins Wza-Wzb-Wzc forming an outer membrane transport system for polysaccharides synthesis,while CPS1357 encoded 17 proteins which were responsible for the synthesis,transportation and regulation of polysaccharides.However,the loss of these two gene clusters resulted in no change of EPSs biosynthesis,biofilm formation,colony morphology and mobility.This may be due to the fact that these two gene clusters were inhibited under the current test conditions or that some of special environmental factors were required to induce their expression.More studies of EPSs synthesis mechanism in V.alginolyticus should be taken to help better understand the adaptability of this species of bacteria in the environments.
Vibrio alginolyticus is one of the most important pathogens for seafood-borne infection in South China.Extracellular polysaccharides（EPSs） are a type of polysaccharides produced by bacteria with a complex structure,and affect the pathogenicity and environmental adaptability of pathogens.Genomic analysis shows that about four gene clusters related to the synthesis of exopolysaccharides exist in V.alginolyticus ZJ-51.In this study,bioinformatic analysis and verification experiment were used to find out the potential functions of two gene clusters of them,i.e.CPS1357 gene cluster and CPS4543 gene cluster.The results show that the gene cluster CPS4543 encoded three homologous proteins Wza-Wzb-Wzc forming an outer membrane transport system for polysaccharides synthesis,while CPS1357 encoded 17 proteins which were responsible for the synthesis,transportation and regulation of polysaccharides.However,the loss of these two gene clusters resulted in no change of EPSs biosynthesis,biofilm formation,colony morphology and mobility.This may be due to the fact that these two gene clusters were inhibited under the current test conditions or that some of special environmental factors were required to induce their expression.More studies of EPSs synthesis mechanism in V.alginolyticus should be taken to help better understand the adaptability of this species of bacteria in the environments.
2017, 8(3): 267-276.
doi: 10.15886/j.cnki.rdswxb.2017.03.004
Abstract:
In order to provide basis for construction of the genomic library of Conus vexillum（C.vexillum）,different methods were used for isolation and extraction of different size fragments of genomic DNA from C.vexillum native to Hainan.Genomic DNA was isolated from venom glands,hepatopancreas and muscle of C.vexillum using three methods of CTAB,spin column and magnetic bead respectively.The genomic DNA fragments were separated by agarose gel electrophoresis and pulsed-field gel electrophoresis,of which the size and distribution range of extracted DNA was detected.The results showed that the genomic DNA could be extracted by all the three methods.The purity and yield of DNAs isolated by CTAB and centrifugal column methods using venom gland of C.vexillum were good and high,which could meet the following experimental requirements.While the yield of the magnetic bead method is less and the purity is not good.The length of most DNA fragments isolated by the centrifugal column method was less than 9 kb,while most fragments’ sizes isolated by CTAB method were more than 20 kb.Among the three kinds of organs,hepatopancreas had highest yield of DNA,but its fragment was dispersed with degradation happened,the DNA yield of venom glands was high but less than hepatopancreas slightly,its integrity was the best;however the DNA yield of muscle was lowest and its fragments was smaller.The high quality genomic DNA fragments with different sizes were separated and prepared successfully by optimized pulsed-field gel electrophoresis.In conclusion,using CTAB method to isolate C.vexillum DNA is better than the other methods for big fragment genomic DNA library construction.Different size genomic DNA fragments recovered by pulsed-field gel electrophoresis would lay a foundation for further genomic library construction of C.vexillum using different gene library vector systems.
In order to provide basis for construction of the genomic library of Conus vexillum（C.vexillum）,different methods were used for isolation and extraction of different size fragments of genomic DNA from C.vexillum native to Hainan.Genomic DNA was isolated from venom glands,hepatopancreas and muscle of C.vexillum using three methods of CTAB,spin column and magnetic bead respectively.The genomic DNA fragments were separated by agarose gel electrophoresis and pulsed-field gel electrophoresis,of which the size and distribution range of extracted DNA was detected.The results showed that the genomic DNA could be extracted by all the three methods.The purity and yield of DNAs isolated by CTAB and centrifugal column methods using venom gland of C.vexillum were good and high,which could meet the following experimental requirements.While the yield of the magnetic bead method is less and the purity is not good.The length of most DNA fragments isolated by the centrifugal column method was less than 9 kb,while most fragments’ sizes isolated by CTAB method were more than 20 kb.Among the three kinds of organs,hepatopancreas had highest yield of DNA,but its fragment was dispersed with degradation happened,the DNA yield of venom glands was high but less than hepatopancreas slightly,its integrity was the best;however the DNA yield of muscle was lowest and its fragments was smaller.The high quality genomic DNA fragments with different sizes were separated and prepared successfully by optimized pulsed-field gel electrophoresis.In conclusion,using CTAB method to isolate C.vexillum DNA is better than the other methods for big fragment genomic DNA library construction.Different size genomic DNA fragments recovered by pulsed-field gel electrophoresis would lay a foundation for further genomic library construction of C.vexillum using different gene library vector systems.
2017, 8(3): 277-283.
doi: 10.15886/j.cnki.rdswxb.2017.03.005
Abstract:
A number of germfree materials were obtained from explants of the same field plant of Pogostemon cablin（Blanco） Benth.These germfree materials were irradiated by60Co-γ ray irradiation at a respective dose of 0,45,60,75 or 90 Gy,from which 172 pieces of 60Co-γ ray mutant material and 1 piece of germfree control material（CK;0 Gy） were produced.The genomic DNAs of 173 germfree materials were extracted and amplified by using PCR with 14 ISSR primers.A total of 297 amplified products were produced,of which there were 68 polymorphic bands,the percentage of polymorphic bands（PPB） was 43.13%,the observed number of alleles（NA）was 1.431 3,the effective number of alleles（Ne） was 1.257 3,the Nei’s gene diversity（H） was 0.146 5,and Shannon index was 0.217 5.According to the obtained genetic similarity coefficient matrix,a phylogenetic tree showing genetic relationships among the 173 materials tested was constructed by UPGMA.This phylogenetic tree diagram showed that at the genetic similarity coefficient（GS） range of 0.09＜GS＜0.42 the 173 materials could be divided into two groups:Group I and CK,that at the GS of 0.44,the Group I could be divided into two subgroups:Group II and material 90 Gy-34,and that at the range of 0.46＜GS＜0.48,the Group II could be divided into two branches:Group III and material 75 Gy-13.Although some of the mutagenic plants induced by radiation at different doses were clustered together,the mutant plants induced at the same radiation dose were generally clustered into the same group.The results showed that 60Co-γ-ray irradiation had significant mutagenic effect on the mutants of P.cablin（Blanco） Benth.Mutation with 60Co-γ ray could be used as an effective method for germplasm innovation of P.cablin（Blanco） Benth.
A number of germfree materials were obtained from explants of the same field plant of Pogostemon cablin（Blanco） Benth.These germfree materials were irradiated by60Co-γ ray irradiation at a respective dose of 0,45,60,75 or 90 Gy,from which 172 pieces of 60Co-γ ray mutant material and 1 piece of germfree control material（CK;0 Gy） were produced.The genomic DNAs of 173 germfree materials were extracted and amplified by using PCR with 14 ISSR primers.A total of 297 amplified products were produced,of which there were 68 polymorphic bands,the percentage of polymorphic bands（PPB） was 43.13%,the observed number of alleles（NA）was 1.431 3,the effective number of alleles（Ne） was 1.257 3,the Nei’s gene diversity（H） was 0.146 5,and Shannon index was 0.217 5.According to the obtained genetic similarity coefficient matrix,a phylogenetic tree showing genetic relationships among the 173 materials tested was constructed by UPGMA.This phylogenetic tree diagram showed that at the genetic similarity coefficient（GS） range of 0.09＜GS＜0.42 the 173 materials could be divided into two groups:Group I and CK,that at the GS of 0.44,the Group I could be divided into two subgroups:Group II and material 90 Gy-34,and that at the range of 0.46＜GS＜0.48,the Group II could be divided into two branches:Group III and material 75 Gy-13.Although some of the mutagenic plants induced by radiation at different doses were clustered together,the mutant plants induced at the same radiation dose were generally clustered into the same group.The results showed that 60Co-γ-ray irradiation had significant mutagenic effect on the mutants of P.cablin（Blanco） Benth.Mutation with 60Co-γ ray could be used as an effective method for germplasm innovation of P.cablin（Blanco） Benth.
2017, 8(3): 284-291.
doi: 10.15886/j.cnki.rdswxb.2017.03.006
Abstract:
Alkaline or neutral invertase（N/A-lnv） is a key enzyme for starch synthesis process in cassava.Chromosome specimens were prepared from the bronze-coloured tender leaves of cassava variety SC6,and 11 members of the cassava neutral or alkaline invertase gene family were physically localized by fluorescence in situ hybridization（FISH） and in situ PCR.The results showed that genes MeNINV5,MeNINV9 and MeNINV10 were located on the chromosome 4.MeNINV9 and MeNINV10 had percentage distances of 68.52 and 95.35 from the signal locus to the centromere on the short arm,respectively,and MeNINV5 had a percentage distance of 22.71 from the signal locus to the centromere on the long arm.MeNINV4 and nINV1 genes were located on the long arm of chromosome 6,and their percentage distances from the signal locus to the centromere are 43.16 and 80.71,respectively;MeNINV6 and MeNINV7 genes were located on the long arms of chromosome 7 and 17,respectively,and their percentage distances from the signal locus to the centromere are 15.38 and 57.97,respectively;MeNINV1,MeNINV2,MeNINV3 and MeNINV8 genes were located on the short arms of chromosome 11,9,5 and 16,respectively,and their percentage distances from the signal locus to the centromere were 40.10,51.88,91.75 and 76.33,respectively.The linkage relationship was discussed between the N/A-lnv gene family and other genes located on cassava chromosomes.
Alkaline or neutral invertase（N/A-lnv） is a key enzyme for starch synthesis process in cassava.Chromosome specimens were prepared from the bronze-coloured tender leaves of cassava variety SC6,and 11 members of the cassava neutral or alkaline invertase gene family were physically localized by fluorescence in situ hybridization（FISH） and in situ PCR.The results showed that genes MeNINV5,MeNINV9 and MeNINV10 were located on the chromosome 4.MeNINV9 and MeNINV10 had percentage distances of 68.52 and 95.35 from the signal locus to the centromere on the short arm,respectively,and MeNINV5 had a percentage distance of 22.71 from the signal locus to the centromere on the long arm.MeNINV4 and nINV1 genes were located on the long arm of chromosome 6,and their percentage distances from the signal locus to the centromere are 43.16 and 80.71,respectively;MeNINV6 and MeNINV7 genes were located on the long arms of chromosome 7 and 17,respectively,and their percentage distances from the signal locus to the centromere are 15.38 and 57.97,respectively;MeNINV1,MeNINV2,MeNINV3 and MeNINV8 genes were located on the short arms of chromosome 11,9,5 and 16,respectively,and their percentage distances from the signal locus to the centromere were 40.10,51.88,91.75 and 76.33,respectively.The linkage relationship was discussed between the N/A-lnv gene family and other genes located on cassava chromosomes.
2017, 8(3): 292-300.
doi: 10.15886/j.cnki.rdswxb.2017.03.007
Abstract:
Seedlings of six cassava cultivars with high resistance,medium resistance or high susceptibility to bacterial blight were selected to observe their leaf anatomical structure characteristics by using microscope.The seedlings were then inoculated with a strain（Xam HN04） of the pathogen of cassava bacterial blight [Xanthomonas axonopodis pv.malvacearum（Xam） ] to determine the change of peroxidase（POD） and polyphenoloxidase（PPO） activities and soluble protein content in the leaves.The results showed that the stoma density and wax content in the leaves were significantly higher in the resistant cassava varieties than in the susceptible ones,indicating that they were positively correlated with the resistance of cassava varieties.The palisade and spongy tissues of the resistant varieties were more compact and tight than those of the susceptible ones.In addition,the spongy tissues of medium resistant and highly susceptible varieties were relatively loose in structure with lots of spaces.The activities of POD and PPO in the leaves inoculated with the pathogen strain Xam HN04 were determined to be positively correlated with the resistance to the bacterial blight,and the content of soluble protein had significant change in the leaves after inoculation.These results implied that the leaf anatomical structure and physiological characteristics could be the markers for cassava resistance to bacterial blight.
Seedlings of six cassava cultivars with high resistance,medium resistance or high susceptibility to bacterial blight were selected to observe their leaf anatomical structure characteristics by using microscope.The seedlings were then inoculated with a strain（Xam HN04） of the pathogen of cassava bacterial blight [Xanthomonas axonopodis pv.malvacearum（Xam） ] to determine the change of peroxidase（POD） and polyphenoloxidase（PPO） activities and soluble protein content in the leaves.The results showed that the stoma density and wax content in the leaves were significantly higher in the resistant cassava varieties than in the susceptible ones,indicating that they were positively correlated with the resistance of cassava varieties.The palisade and spongy tissues of the resistant varieties were more compact and tight than those of the susceptible ones.In addition,the spongy tissues of medium resistant and highly susceptible varieties were relatively loose in structure with lots of spaces.The activities of POD and PPO in the leaves inoculated with the pathogen strain Xam HN04 were determined to be positively correlated with the resistance to the bacterial blight,and the content of soluble protein had significant change in the leaves after inoculation.These results implied that the leaf anatomical structure and physiological characteristics could be the markers for cassava resistance to bacterial blight.
2017, 8(3): 301-306.
doi: 10.15886/j.cnki.rdswxb.2017.03.008
Abstract:
In order to explore the relationship between leaf structure and drought resistance of rubber trees,leaves rubber trees collected from 5 rubber clones（Hevea brasiliensis） were treated by using paraffin section technique to observe their anatomical structures such as palisade tissue thickness,leaf thickness,main vein thickness,etc.under optical microscope.The data were subjected to multiple comparison and subordinate function analysis to analyze the drought tolerance of the leaves of the 5 rubber clones.The results showed that there were significant difference among the 5 rubber clones in leaf cuticle thickness,palisade tissue thickness,thickness and main vein thickness.Multiple comparison and subordinate function analysis showed the drought resistance of these 5 clones was in the order of Baoting 933＞Reken 525＞RRIM 513＞Haiken 1＞Reyan 106.
In order to explore the relationship between leaf structure and drought resistance of rubber trees,leaves rubber trees collected from 5 rubber clones（Hevea brasiliensis） were treated by using paraffin section technique to observe their anatomical structures such as palisade tissue thickness,leaf thickness,main vein thickness,etc.under optical microscope.The data were subjected to multiple comparison and subordinate function analysis to analyze the drought tolerance of the leaves of the 5 rubber clones.The results showed that there were significant difference among the 5 rubber clones in leaf cuticle thickness,palisade tissue thickness,thickness and main vein thickness.Multiple comparison and subordinate function analysis showed the drought resistance of these 5 clones was in the order of Baoting 933＞Reken 525＞RRIM 513＞Haiken 1＞Reyan 106.
2017, 8(3): 307-312.
doi: 10.15886/j.cnki.rdswxb.2017.03.009
Abstract:
T Trees of seedless litchi A4（Litchi chinensis Sonn.） of 10 years old were used as the experimental material to regularly observe their physiological fruit drops during the fruit growth and development after blossom fall.During the whole process of fruit development,the seedless litchi A4 showed four fruit-dropping peaks which appeared at 9 to 12 days,21 to 27 days,39 to 42 days and 51 to 60 days（before harvest）,respectively,after blossom fall.Among the four stages of physiological fruit drop,the number of dropped fruits was significantly higher at the first time stage than at the other three stages.However,the rate of fruit drop at the pre-harvest stage was up to 69.84%,which was significantly higher than that at the other fruit drop stages.The abscission site of physiological fruit drop at the four stages was consistent,and the fruits all fell from the union between the flower axis and the subaxis at the end of the fruit stem.The numbert of single fruit drop was 20% higher than that of paired fruit drop,and the yellow fruit（fruit peel color turned yellow） was dropped 3.65 times higher than that the red fruit.Moreover,the yellow fruits were lower in transverse diameter,longitudinal diameter and single fruit weight than the red fruits.In this context,the pre-harvest fruit drop was the main factor of the yield loss for the seedless litchi A4.The small fruit was readier to drop when the fruit skin just turned yellow.In the future,attention should be focused on the regulation of the last two stages of fruit drop in cultivation,especially the pre-harvest fruit drop.
T Trees of seedless litchi A4（Litchi chinensis Sonn.） of 10 years old were used as the experimental material to regularly observe their physiological fruit drops during the fruit growth and development after blossom fall.During the whole process of fruit development,the seedless litchi A4 showed four fruit-dropping peaks which appeared at 9 to 12 days,21 to 27 days,39 to 42 days and 51 to 60 days（before harvest）,respectively,after blossom fall.Among the four stages of physiological fruit drop,the number of dropped fruits was significantly higher at the first time stage than at the other three stages.However,the rate of fruit drop at the pre-harvest stage was up to 69.84%,which was significantly higher than that at the other fruit drop stages.The abscission site of physiological fruit drop at the four stages was consistent,and the fruits all fell from the union between the flower axis and the subaxis at the end of the fruit stem.The numbert of single fruit drop was 20% higher than that of paired fruit drop,and the yellow fruit（fruit peel color turned yellow） was dropped 3.65 times higher than that the red fruit.Moreover,the yellow fruits were lower in transverse diameter,longitudinal diameter and single fruit weight than the red fruits.In this context,the pre-harvest fruit drop was the main factor of the yield loss for the seedless litchi A4.The small fruit was readier to drop when the fruit skin just turned yellow.In the future,attention should be focused on the regulation of the last two stages of fruit drop in cultivation,especially the pre-harvest fruit drop.
2017, 8(3): 313-317,377.
doi: 10.15886/j.cnki.rdswxb.2017.03.010
Abstract:
Dendrobium sinense is a perennial epiphytic orchid,which belongs to the genus of Dendrobium and the family of Orchidaceae.Under nature conditions,D.sinense has a low seed setting rate and the environmental requirements for seed germination is very stringent.Besides sexual propagation,asexual ways like clonal propagation is also found in D.sinense.In this study,five transects were set up in Bawang Ridge of Hainan Province to monitor the dynamic change of D.sinense population and study the reproductive allocation rules of D.sinense plants at different age,in order to supply scientific evidence for the conservation of epiphytic orchids.The results showed that during the whole life history of D.sinense,individuals with at least four pseudobulbs could have sexual reproduction,and the investment paid into sexual reproduction increased year by year.Whereas,the clonal propagation of D.sinense was not limited by individual size.According to the ratio of reproductive organ biomass to total biomass,the proportion of resources devoted to reproductive activities was maintained at about 27% through the whole life history.Clonal reproduction was found always being the dominant ones between the two reproduction methods.
Dendrobium sinense is a perennial epiphytic orchid,which belongs to the genus of Dendrobium and the family of Orchidaceae.Under nature conditions,D.sinense has a low seed setting rate and the environmental requirements for seed germination is very stringent.Besides sexual propagation,asexual ways like clonal propagation is also found in D.sinense.In this study,five transects were set up in Bawang Ridge of Hainan Province to monitor the dynamic change of D.sinense population and study the reproductive allocation rules of D.sinense plants at different age,in order to supply scientific evidence for the conservation of epiphytic orchids.The results showed that during the whole life history of D.sinense,individuals with at least four pseudobulbs could have sexual reproduction,and the investment paid into sexual reproduction increased year by year.Whereas,the clonal propagation of D.sinense was not limited by individual size.According to the ratio of reproductive organ biomass to total biomass,the proportion of resources devoted to reproductive activities was maintained at about 27% through the whole life history.Clonal reproduction was found always being the dominant ones between the two reproduction methods.
2017, 8(3): 318-323.
doi: 10.15886/j.cnki.rdswxb.2017.03.011
Abstract:
Shanlan upland rice was cultivated under three patterns:paddy,rice-straw mulching and upland to determine their drought-tolerant physiological parameters,agronomic traits and yield components in the field trial.The results showed that the paddy cultivation alleviated drought stress on Shanlan upland rice,reduced the contents of POD,MDA and soluble protein and increased the chlorophyll content of the flag leaves.Rice straw mulching had similar,although less,effect to the paddy cultivation.Compared with the conventional upland cultivation,the paddy and rice straw mulching cultivation increased the plant height of Shanlan upland rice by 30.62% and 16.69%,the flag leaf length by 14.32% and 6.62%,the available? tillers by 64.7% and 26.47% and the yield by 267.44% and 91.04%,and shortened the growth stage by 12 and 5 days,respectively.Under paddy field conditions Shanlan upland rice has many advantages such as lower drought stress,optimal agronomic traits and higher yield.This study may provide a scientific basis for further research on cultivation pattern of Shanlan upland rice shifting from traditional upland to paddy field.
Shanlan upland rice was cultivated under three patterns:paddy,rice-straw mulching and upland to determine their drought-tolerant physiological parameters,agronomic traits and yield components in the field trial.The results showed that the paddy cultivation alleviated drought stress on Shanlan upland rice,reduced the contents of POD,MDA and soluble protein and increased the chlorophyll content of the flag leaves.Rice straw mulching had similar,although less,effect to the paddy cultivation.Compared with the conventional upland cultivation,the paddy and rice straw mulching cultivation increased the plant height of Shanlan upland rice by 30.62% and 16.69%,the flag leaf length by 14.32% and 6.62%,the available? tillers by 64.7% and 26.47% and the yield by 267.44% and 91.04%,and shortened the growth stage by 12 and 5 days,respectively.Under paddy field conditions Shanlan upland rice has many advantages such as lower drought stress,optimal agronomic traits and higher yield.This study may provide a scientific basis for further research on cultivation pattern of Shanlan upland rice shifting from traditional upland to paddy field.
2017, 8(3): 324-329.
doi: 10.15886/j.cnki.rdswxb.2017.03.012
Abstract:
Leguminous plant was an important resource of green manures in the tropics and subtropics.Seven accessions of wild Sesbania plant germplasm under legume family were collected from various localities in Hainan,Guangdong and Fujian provinces and were applied as green manure in the soil at different time to observe their dynamic effects on the organic matter content in the acid soil.The results indicated that different Sesbania green manures after application had different effect on the soil organic matter content,which changed with the time of application,but the Sesbania green manures all could increase significantly（P＜0.05） the soil organic matter content after one year of application.The soil organic content continuously decreased with the time of application of the Sesbania green manures.
Leguminous plant was an important resource of green manures in the tropics and subtropics.Seven accessions of wild Sesbania plant germplasm under legume family were collected from various localities in Hainan,Guangdong and Fujian provinces and were applied as green manure in the soil at different time to observe their dynamic effects on the organic matter content in the acid soil.The results indicated that different Sesbania green manures after application had different effect on the soil organic matter content,which changed with the time of application,but the Sesbania green manures all could increase significantly（P＜0.05） the soil organic matter content after one year of application.The soil organic content continuously decreased with the time of application of the Sesbania green manures.
2017, 8(3): 330-334.
doi: 10.15886/j.cnki.rdswxb.2017.03.013
Abstract:
Liriomyza leafminers are common pests infesting cowpea Vigna sesquipedalis in Hainan Island,and their associated parasitoids are important natural enemies.For further conservation and promotion of the natural enemies for the control of leafminers,field surveys of the associated parasitoids and parasitism as well as the leafminers were conducted in the field of cowpea planted in winter in Haikou,Qionghai,Danzhou and Sanya,Hainan Province.Two species of leafminers and five species of their parasitoids were collected from the surveys.The relative abundances of the two species of leafminers,Liromyza trifolii（Burgess） and L.sativae Blanchard,were79.5% and 20.5%,respectively.Both L.trifolii and L.sativae were found at the four sampling sites,while L.trifolii was dominant in Haikou and Sanya,and L.sativave dominant in Qionghai and Danzhou.Of the five species of their parasitoids,Opius dimidiatus（Ashmead） belongs to the family of Braconidae,while Chrysocharis pentheus（Walker）,Hemiptarsenus varicornis（Girault）,Neochrysocharis formosa（Westwood） and N.punctiventris（Crawford） to the family of Eulophidae.O.dimidiatus and H.varicornis were relatively abundant with their high relative abundances being up to 51.8% and 29.2%,respectively.The parasitoids had different percentages of parasitism over the leaminers from site to site in a descending order:51.4% in Qionghai,45.4% in Sanya,17.0% in Danzhou and 10.5% in Haikou.They had a high diversity and parasitism percentage,and should,hence,be well conserved and utilized to control the two species of leafminers infesting cowpea planted in winter in the Island.
Liriomyza leafminers are common pests infesting cowpea Vigna sesquipedalis in Hainan Island,and their associated parasitoids are important natural enemies.For further conservation and promotion of the natural enemies for the control of leafminers,field surveys of the associated parasitoids and parasitism as well as the leafminers were conducted in the field of cowpea planted in winter in Haikou,Qionghai,Danzhou and Sanya,Hainan Province.Two species of leafminers and five species of their parasitoids were collected from the surveys.The relative abundances of the two species of leafminers,Liromyza trifolii（Burgess） and L.sativae Blanchard,were79.5% and 20.5%,respectively.Both L.trifolii and L.sativae were found at the four sampling sites,while L.trifolii was dominant in Haikou and Sanya,and L.sativave dominant in Qionghai and Danzhou.Of the five species of their parasitoids,Opius dimidiatus（Ashmead） belongs to the family of Braconidae,while Chrysocharis pentheus（Walker）,Hemiptarsenus varicornis（Girault）,Neochrysocharis formosa（Westwood） and N.punctiventris（Crawford） to the family of Eulophidae.O.dimidiatus and H.varicornis were relatively abundant with their high relative abundances being up to 51.8% and 29.2%,respectively.The parasitoids had different percentages of parasitism over the leaminers from site to site in a descending order:51.4% in Qionghai,45.4% in Sanya,17.0% in Danzhou and 10.5% in Haikou.They had a high diversity and parasitism percentage,and should,hence,be well conserved and utilized to control the two species of leafminers infesting cowpea planted in winter in the Island.
2017, 8(3): 335-340.
doi: 10.15886/j.cnki.rdswxb.2017.03.014
Abstract:
Konjac glucomannan（KGM） was blended with tara gum（TG） at a given ratio.The blends were determined in terms of rheological properties by using a rotational rheometer,and the molecular interaction between KGM and TG was analyzed based on molecular dynamics and topological analysis to explore the effect of tara gum on the network topological structure of the KGM molecular chain.The results revealed a synergistic effect in molecules between TG and KGM with hydrogen bonding playing the main role in molecular chain.Adding of TG into KGM resulted in the enhancement of strength and density of the topological entanglement.The mechanical properties of the blends were obviously strengthened,which successfully verified the experimental results of the theological property test between the KGM and TG.
Konjac glucomannan（KGM） was blended with tara gum（TG） at a given ratio.The blends were determined in terms of rheological properties by using a rotational rheometer,and the molecular interaction between KGM and TG was analyzed based on molecular dynamics and topological analysis to explore the effect of tara gum on the network topological structure of the KGM molecular chain.The results revealed a synergistic effect in molecules between TG and KGM with hydrogen bonding playing the main role in molecular chain.Adding of TG into KGM resulted in the enhancement of strength and density of the topological entanglement.The mechanical properties of the blends were obviously strengthened,which successfully verified the experimental results of the theological property test between the KGM and TG.
2017, 8(3): 341-347.
doi: 10.15886/j.cnki.rdswxb.2017.03.015
Abstract:
A survey was made of diversity of butterflies in Nanlihu National Wetland Park of Hainan Province from May to October 2016,and recorded were 45 species,32 genera and 7 families including Papi Iionidae,Danaidae,Nymphalidae,Satyridae,Lycaenidae,Pieridae and Hesperiidae.Family Papilionidae has 11 species and is the most diverse group,followed by Nymphalidae,and Hesperiidae is the last with only one species.Fauna analysis showed that numerous species of butterflies were cosmopolitan in the Nanlihu National Wetland Park,dominated by the species of East Palaearctic realm + Oriental realms in the world zoogeographic regions.Among the 45 species,32 species were distributed both in the East Palaearctic region and the Oriental region,accounting for 71.11%,and there were 8 different distribution patterns in the zoogeographic regions of China,dominated by the species distributed in the Jianghuai-Central China-Eastern China-Southern China regions（33.3%）and in the Central China-Eastern China-Southern China regions（24.44%）.
A survey was made of diversity of butterflies in Nanlihu National Wetland Park of Hainan Province from May to October 2016,and recorded were 45 species,32 genera and 7 families including Papi Iionidae,Danaidae,Nymphalidae,Satyridae,Lycaenidae,Pieridae and Hesperiidae.Family Papilionidae has 11 species and is the most diverse group,followed by Nymphalidae,and Hesperiidae is the last with only one species.Fauna analysis showed that numerous species of butterflies were cosmopolitan in the Nanlihu National Wetland Park,dominated by the species of East Palaearctic realm + Oriental realms in the world zoogeographic regions.Among the 45 species,32 species were distributed both in the East Palaearctic region and the Oriental region,accounting for 71.11%,and there were 8 different distribution patterns in the zoogeographic regions of China,dominated by the species distributed in the Jianghuai-Central China-Eastern China-Southern China regions（33.3%）and in the Central China-Eastern China-Southern China regions（24.44%）.
2017, 8(3): 348-352.
doi: 10.15886/j.cnki.rdswxb.2017.03.016
Abstract:
Soil samples collected were treated by microwave digestion of nitric acid hydrochloric acid and hydrofluoric acid system to determine arsenic and mercury in soil simultaneously by using double channel atomic fluorescence spectrometry.The experimental conditions for treating and analyzing samples were optimized;the accuracy of the method was validated by determination of the certified reference materials,and spike recovery test.The results showed that the concentration curve was linear within the range of 0-50.0 μg·L-1 of arsenic and 0-10.0 μg·L-1 of mercury,the detection limits were 0.012 μg·L-1 and 0.049 μg·L-1 for arsenic and mercury,respectively.This method was used to determine arsenic and mercury in different soil reference materials,and the results fell within the allowable range.The relative standard deviations（RSD） were in the range of1.2%-3.5% and 1.8%-4.2%,and the recoveries of the soil samples collected were 96%-112% and 90%-117% for arsenic and mercury,respectively.This method was proved to be good in stability,high in precision,easy in operation and low in cost,and can be applied to determine arsenic and mercury simultaneously in a large number of soil samples.
Soil samples collected were treated by microwave digestion of nitric acid hydrochloric acid and hydrofluoric acid system to determine arsenic and mercury in soil simultaneously by using double channel atomic fluorescence spectrometry.The experimental conditions for treating and analyzing samples were optimized;the accuracy of the method was validated by determination of the certified reference materials,and spike recovery test.The results showed that the concentration curve was linear within the range of 0-50.0 μg·L-1 of arsenic and 0-10.0 μg·L-1 of mercury,the detection limits were 0.012 μg·L-1 and 0.049 μg·L-1 for arsenic and mercury,respectively.This method was used to determine arsenic and mercury in different soil reference materials,and the results fell within the allowable range.The relative standard deviations（RSD） were in the range of1.2%-3.5% and 1.8%-4.2%,and the recoveries of the soil samples collected were 96%-112% and 90%-117% for arsenic and mercury,respectively.This method was proved to be good in stability,high in precision,easy in operation and low in cost,and can be applied to determine arsenic and mercury simultaneously in a large number of soil samples.
2017, 8(3): 353-358,370.
doi: 10.15886/j.cnki.rdswxb.2017.03.017
Abstract:
Experimental conditions for reduction method and activated carbon adsorption method were optimized to remove Cr（VI） in water,and both methods were combined to observe their effect on removal of Cr（VI）.The orthogonal experiments and double-check test were used to optimize the reduction method for removal of Cr（VI）,resulting in optimum conditions for the reduction method with sodium metabisulfite,sodium bisulfite,sodium sulfite,sodium hydrosulfite and sodium thiosulfate as reducing agents.Under these optimal conditions,the reducing agents had a Cr（VI） removal rate of 96.59 %-99.48% in the water body.Activated carbon modified with manganese nitrate at different concentrations produced different effects on Cr（VI） removal and had the highest removal rate when modified with manganese nitrate at the concentration of 0.03 mol/L.The modified activated carbon had better removal effect than the unmodified one.The removal rate was affected by pH,initial concentration of Cr（VI） and treatment time.When the pH was 3,the removal rate was the highest（94.6%）.The modified activated carbon had better removal effect when the contaminated water contained lower initial concentration of Cr（VI）,and the Cr（VI） removal rates increased fast at the early and middle stage of absorption.The combined reduction and modified activated carbon absorption method had better effect on removal of Cr（VI）than the reduction method or the modified activated carbon absorption method alone.The simulated water samples collected from Haidian Stream,Haikou,Hainan,China were treated by using the combined reduction and modified activated carbon adsorption method,and the results showed a satisfactory treatment of the actual sample matrix by using the combined method.
Experimental conditions for reduction method and activated carbon adsorption method were optimized to remove Cr（VI） in water,and both methods were combined to observe their effect on removal of Cr（VI）.The orthogonal experiments and double-check test were used to optimize the reduction method for removal of Cr（VI）,resulting in optimum conditions for the reduction method with sodium metabisulfite,sodium bisulfite,sodium sulfite,sodium hydrosulfite and sodium thiosulfate as reducing agents.Under these optimal conditions,the reducing agents had a Cr（VI） removal rate of 96.59 %-99.48% in the water body.Activated carbon modified with manganese nitrate at different concentrations produced different effects on Cr（VI） removal and had the highest removal rate when modified with manganese nitrate at the concentration of 0.03 mol/L.The modified activated carbon had better removal effect than the unmodified one.The removal rate was affected by pH,initial concentration of Cr（VI） and treatment time.When the pH was 3,the removal rate was the highest（94.6%）.The modified activated carbon had better removal effect when the contaminated water contained lower initial concentration of Cr（VI）,and the Cr（VI） removal rates increased fast at the early and middle stage of absorption.The combined reduction and modified activated carbon absorption method had better effect on removal of Cr（VI）than the reduction method or the modified activated carbon absorption method alone.The simulated water samples collected from Haidian Stream,Haikou,Hainan,China were treated by using the combined reduction and modified activated carbon adsorption method,and the results showed a satisfactory treatment of the actual sample matrix by using the combined method.
2017, 8(3): 359-363,377.
doi: 10.15886/j.cnki.rdswxb.2017.03.018
Abstract:
The reducing sugar and total sugar contents of the leaves of vegetable sweet potato（Dioscorea esculenta（Lour.） Burkill） were determined by using the 3’5’-dinitrosalicylic acid（DNS） method to indirectly determine the leaf content of polysaccharides of three vegetable sweet potato varieties.The optimum conditions for the determination of reducing sugar and total contents were as follows:Optimum wavelength 493 nm,DNS reagent 2.0 mL,coloring reaction10 min,and setting time 10 min.For the reducing sugar and total sugar,the best extraction conditions would be boiling water bath for 30 min.The total sugar was hydrolyzed with hydrochloric acid at a rate of 2.0 mL,and extracted in boiling water bath for 20 min.With this method the polysaccharide contents of the leaves of the three vegetable sweet potato varieties were 12.63,13.49 and 18.51 mg·g-1 FW respectively.The repeatability and recovery of this method meet the test requirements.It is concluded that this method can be used for the determination of polysaccharide content in vegetable sweet potato leaves,and can also be used for the determination of reducing sugar and total sugar.
The reducing sugar and total sugar contents of the leaves of vegetable sweet potato（Dioscorea esculenta（Lour.） Burkill） were determined by using the 3’5’-dinitrosalicylic acid（DNS） method to indirectly determine the leaf content of polysaccharides of three vegetable sweet potato varieties.The optimum conditions for the determination of reducing sugar and total contents were as follows:Optimum wavelength 493 nm,DNS reagent 2.0 mL,coloring reaction10 min,and setting time 10 min.For the reducing sugar and total sugar,the best extraction conditions would be boiling water bath for 30 min.The total sugar was hydrolyzed with hydrochloric acid at a rate of 2.0 mL,and extracted in boiling water bath for 20 min.With this method the polysaccharide contents of the leaves of the three vegetable sweet potato varieties were 12.63,13.49 and 18.51 mg·g-1 FW respectively.The repeatability and recovery of this method meet the test requirements.It is concluded that this method can be used for the determination of polysaccharide content in vegetable sweet potato leaves,and can also be used for the determination of reducing sugar and total sugar.
2017, 8(3): 364-370.
doi: 10.15886/j.cnki.rdswxb.2017.03.019
Abstract:
Bean flower thrips,Megalurothrips usitatus（Bagnall）,is one of the major pests in cowpeas grown in Hainan,China,affecting the quality of cowpeas.From different geographical populations of M.usitatus collected,the total DNA of M.usitatus was extracted by using TIANamp Genmmic DNA Kit,and the mt DNA COI gene sequence was sequenced,based on which a phylogenetic tree was constructed.The enzyme activity was determined by using spectrophotometer.The results showed that the genetic distance between the different geographical populations was very small,and that there was no significant genetic differentiation with the change of geographical location.Determination of antioxidant enzyme activity showed significant difference in glutathione-STransferase（GST） activity between different geographic populations.There was no significant difference in SOD activity between different geographic populations.There was significant difference in CAT activity between individual populations and other geographic populations.
Bean flower thrips,Megalurothrips usitatus（Bagnall）,is one of the major pests in cowpeas grown in Hainan,China,affecting the quality of cowpeas.From different geographical populations of M.usitatus collected,the total DNA of M.usitatus was extracted by using TIANamp Genmmic DNA Kit,and the mt DNA COI gene sequence was sequenced,based on which a phylogenetic tree was constructed.The enzyme activity was determined by using spectrophotometer.The results showed that the genetic distance between the different geographical populations was very small,and that there was no significant genetic differentiation with the change of geographical location.Determination of antioxidant enzyme activity showed significant difference in glutathione-STransferase（GST） activity between different geographic populations.There was no significant difference in SOD activity between different geographic populations.There was significant difference in CAT activity between individual populations and other geographic populations.
2017, 8(3): 371-376.
doi: 10.15886/j.cnki.rdswxb.2017.03.020
Abstract:
An attempt was made to develop airway inflammation murine model induced by the recombinant Blo t21 allergen.The Blo t 21 gene sequences were obtained from NCBI Gen Bank,then optimized,synthesized and inserted into the prokaryotic expression vector PQE80 L.The recombinant Blo t 21 was expressed in E.coli bacteria,and purified by NI-NTA agarose.Twelve BALB/c mice were divided randomly into control group（PBS group,n=6） and rBlo t 21-induced group（rBlo t 21 group,n=6）.After sensitization by intraperitoneal injection（i.p） and challenged by intratracheal instillation of rBlo t 21,the total serum IgE levels were measured by ELISA;the lungs were fixed and stained with haematoxylin and eosin（H＆E）.The recombinant Blo t 21 allergen was expressed successfully in E.coli and purified by Ni-NTA affinity chromatography.Furthermore,the airway inflammation murine model were induced by the recombinant Blo t 21 allergen.Compared with the control group（PBS group）,the total serum IgE levels rose obviously in the rBlo t 21 group（p＜0.005）.Mice in the rBlo t 21 group showed inflammatory cell infiltration in airway by haematoxylin and eosin（H＆E）.The airway inflammation murine model was induced successfully by the recombinant Blo t 21 allergen.
An attempt was made to develop airway inflammation murine model induced by the recombinant Blo t21 allergen.The Blo t 21 gene sequences were obtained from NCBI Gen Bank,then optimized,synthesized and inserted into the prokaryotic expression vector PQE80 L.The recombinant Blo t 21 was expressed in E.coli bacteria,and purified by NI-NTA agarose.Twelve BALB/c mice were divided randomly into control group（PBS group,n=6） and rBlo t 21-induced group（rBlo t 21 group,n=6）.After sensitization by intraperitoneal injection（i.p） and challenged by intratracheal instillation of rBlo t 21,the total serum IgE levels were measured by ELISA;the lungs were fixed and stained with haematoxylin and eosin（H＆E）.The recombinant Blo t 21 allergen was expressed successfully in E.coli and purified by Ni-NTA affinity chromatography.Furthermore,the airway inflammation murine model were induced by the recombinant Blo t 21 allergen.Compared with the control group（PBS group）,the total serum IgE levels rose obviously in the rBlo t 21 group（p＜0.005）.Mice in the rBlo t 21 group showed inflammatory cell infiltration in airway by haematoxylin and eosin（H＆E）.The airway inflammation murine model was induced successfully by the recombinant Blo t 21 allergen.
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