2012 Vol. 3, No. 1
Abstract
PDF 425KB
2012, 3(1): 1-10.
doi: 10.15886/j.cnki.rdswxb.2012.01.016
Abstract:
In order to identify the phylogenetic relationship among two grouper hybrids（Qinglong grouper and Hulong grouper） and their parents（Epinephelus coioides♀,Epinephelus coioides♀ and E.lanceolatus♂）,their mitochondrial cytochrome oxidase subunit Ⅰ（COⅠ） gene fragments were amplified by PCR,and the 1551 base-pair nucleotide sequences of COⅠ were examined.The results show that all 15 sequences are grouped into 9 haplotypes and 249 nucleotide polymorphic loci in COⅠ gene fragments.Sequence divergences and genetic distance analysis showed all the groupers shared 88.1% to 100% similarities in nucleotide sequence,indicating there is no significant genetic difference among these groupers.The two COⅠ haplotypes of Hulong grouper showed 99% and 100% similarities with the haplotype of the female parent E.fuscoguttatus,respectively,but only 88.1% similarity with the male parent E.lanceolatus.The two COⅠ haplotypes in Qinglong grouper had similarities of 99.7% to 100% with the three haplotypes of the female parent E.coioides,and only of 89.3% and 89.4% with the male parent E.lanceolatus.The results indicated that the two grouper hybrids were inherited from their maternal parent in mitochondrial COⅠ genes.
In order to identify the phylogenetic relationship among two grouper hybrids（Qinglong grouper and Hulong grouper） and their parents（Epinephelus coioides♀,Epinephelus coioides♀ and E.lanceolatus♂）,their mitochondrial cytochrome oxidase subunit Ⅰ（COⅠ） gene fragments were amplified by PCR,and the 1551 base-pair nucleotide sequences of COⅠ were examined.The results show that all 15 sequences are grouped into 9 haplotypes and 249 nucleotide polymorphic loci in COⅠ gene fragments.Sequence divergences and genetic distance analysis showed all the groupers shared 88.1% to 100% similarities in nucleotide sequence,indicating there is no significant genetic difference among these groupers.The two COⅠ haplotypes of Hulong grouper showed 99% and 100% similarities with the haplotype of the female parent E.fuscoguttatus,respectively,but only 88.1% similarity with the male parent E.lanceolatus.The two COⅠ haplotypes in Qinglong grouper had similarities of 99.7% to 100% with the three haplotypes of the female parent E.coioides,and only of 89.3% and 89.4% with the male parent E.lanceolatus.The results indicated that the two grouper hybrids were inherited from their maternal parent in mitochondrial COⅠ genes.
2012, 3(1): 11-15.
doi: 10.15886/j.cnki.rdswxb.2012.01.017
Abstract:
Juvenile Litopenaeus vannamei were treated under different temperatures,salinities,pH levels and feeding to determine their release rates of inorganic phosphorus,nitrite,nitric nitrogen and ammonia nitrogen.The results indicate that temperature,salinity,pH value and feeding influence the metabolism of the juvenile L.vannameii.At the temperature ranging from 15 ℃ to 30 ℃ the juvenile L.vannameii increased their release rates of phosphorus,nitrite,nitric nitrogen and ammonia nitrogen with the temperature,and had the highest release rates of nitrogen and phosphorus at 30 ℃.Within the salinity range of 5—35 the juvenile L.vannameii improved their release rate of nitrogen and phosphorus with the salinity but lowered their release rates of nitrogen and phosphorus to minimum at the salinity of 30,and the salinity of 30 gave a significant effect（P＜0.01） on the release rate of ammonia nitrogen.At the pH range of 6.5—9.0 the juvenile L.vannameii decreased their release rate of phosphorus significantly（P＜0.05） and raised their release rates of nitric nitrogen and ammonia nitrogen significantly（P＜0.01） with pH value.The release rate of ammonia nitrogen came to a maximum high at a pH value of around 8.5,while the release rate of nitrite changed little.Feeding had significant impact on the metabolism of the juvenile L.vannameii.The fed juvenile L.vannameii enhanced their release rate of phosphorus,nitrite,nitric nitrogen and ammonia nitrogen by 94.7%,50.0%,60.0% and 94.7%,separately,as against those without feeding,which shows an evident increase in protein metabolism in the fed juveniles.
Juvenile Litopenaeus vannamei were treated under different temperatures,salinities,pH levels and feeding to determine their release rates of inorganic phosphorus,nitrite,nitric nitrogen and ammonia nitrogen.The results indicate that temperature,salinity,pH value and feeding influence the metabolism of the juvenile L.vannameii.At the temperature ranging from 15 ℃ to 30 ℃ the juvenile L.vannameii increased their release rates of phosphorus,nitrite,nitric nitrogen and ammonia nitrogen with the temperature,and had the highest release rates of nitrogen and phosphorus at 30 ℃.Within the salinity range of 5—35 the juvenile L.vannameii improved their release rate of nitrogen and phosphorus with the salinity but lowered their release rates of nitrogen and phosphorus to minimum at the salinity of 30,and the salinity of 30 gave a significant effect（P＜0.01） on the release rate of ammonia nitrogen.At the pH range of 6.5—9.0 the juvenile L.vannameii decreased their release rate of phosphorus significantly（P＜0.05） and raised their release rates of nitric nitrogen and ammonia nitrogen significantly（P＜0.01） with pH value.The release rate of ammonia nitrogen came to a maximum high at a pH value of around 8.5,while the release rate of nitrite changed little.Feeding had significant impact on the metabolism of the juvenile L.vannameii.The fed juvenile L.vannameii enhanced their release rate of phosphorus,nitrite,nitric nitrogen and ammonia nitrogen by 94.7%,50.0%,60.0% and 94.7%,separately,as against those without feeding,which shows an evident increase in protein metabolism in the fed juveniles.
2012, 3(1): 16-21.
doi: 10.15886/j.cnki.rdswxb.2012.01.018
Abstract:
Anaesthetics,as a means of reducing stress reaction,may have a role in the pearl seeding process.Anaesthetic chemicals were identified to facilitate the safe and effective anesthetization of wing pearl oysters（Pteria penguin（Röding）） in seeding.Two anaesthetic chemicals,2-phenoxyethanol and benzocaine,were assessed for their ability to relax the wing pearl oyster.These reagents of different concentrations were added into containers of the oysters to observe their reactions at the temperatures ranging from 21,23,25 and 27 ℃.At 25 ℃ 2-phenoxyethanol of 0.1%—0.3%（V/V） and benzocaine of 500,800,1 000 mg·L-1 appeared promising.And 2-phenoxyethanol and benzocaine were selected to determine their effects on the time to relaxation and to recovery and on survival of the oysters after 7 days of relaxation.It was found that as anesthetic concentrations of the reagents increased,the time to relaxation of the oysters decreased while the time to recovery tended to increase.Increased duration of exposure to the relaxants increased the time to recovery.When the temperature increased both the time to relaxation and to recovery of the oysters decreased.The highest proportion of the relaxed oysters（100%） within 30 min and the shortest exposure time required for anaesthesia were recorded in the treatments of the oysters with 0.2% 2-phenoxyethanol or 1 000 mg·L-1 benzocaine,and the treated oysters had no mortalities after 7 days of the treatment.
Anaesthetics,as a means of reducing stress reaction,may have a role in the pearl seeding process.Anaesthetic chemicals were identified to facilitate the safe and effective anesthetization of wing pearl oysters（Pteria penguin（Röding）） in seeding.Two anaesthetic chemicals,2-phenoxyethanol and benzocaine,were assessed for their ability to relax the wing pearl oyster.These reagents of different concentrations were added into containers of the oysters to observe their reactions at the temperatures ranging from 21,23,25 and 27 ℃.At 25 ℃ 2-phenoxyethanol of 0.1%—0.3%（V/V） and benzocaine of 500,800,1 000 mg·L-1 appeared promising.And 2-phenoxyethanol and benzocaine were selected to determine their effects on the time to relaxation and to recovery and on survival of the oysters after 7 days of relaxation.It was found that as anesthetic concentrations of the reagents increased,the time to relaxation of the oysters decreased while the time to recovery tended to increase.Increased duration of exposure to the relaxants increased the time to recovery.When the temperature increased both the time to relaxation and to recovery of the oysters decreased.The highest proportion of the relaxed oysters（100%） within 30 min and the shortest exposure time required for anaesthesia were recorded in the treatments of the oysters with 0.2% 2-phenoxyethanol or 1 000 mg·L-1 benzocaine,and the treated oysters had no mortalities after 7 days of the treatment.
2012, 3(1): 22-27,31.
doi: 10.15886/j.cnki.rdswxb.2012.01.001
Abstract:
Growth of Agrobacterium tumefaciens EHA105,the quality of the competent cells and the heat-shock temperature during transformation are the three main factors affecting the transformation efficiency of A.tumefaciens EHA105.The growth of the strain EHA105 with 48 h continuous culture was observed based on which the growth curve was plotted.At the same time,different concentrations of CaCl2 and different temperatures in heat-shocking during the transformation were tested in preparing the competent cells of EHA105.The number of positive transformants was determined and the factors affecting introduction of exogenous DNA into the strain EHA105 by using the freeze-thaw method were identified.When the OD600 value ranged from 1.0 to 1.5,the strain EHA105 was found at the logarithmic growth phase and had the highest vitality.No significant difference was observed in the transformation rates of competent cells prepared with the CaCl2 at the concentration of between 6 mmol·L-1 and 10 mmol·L-1,but the best transformation rate was 5.322×106·μg-1 at 10 mmol·L-1 CaCl2.No significant difference was found in transformation rates at the heat-shock temperatures from 20 ℃ to 37 ℃ during transformation,but the best transformation rate（5.550×106·μg-1） was achieved at 37 ℃.The results provide a reference for improving the transformation efficiency of A.tumefaciens EHA105 competent cells.
Growth of Agrobacterium tumefaciens EHA105,the quality of the competent cells and the heat-shock temperature during transformation are the three main factors affecting the transformation efficiency of A.tumefaciens EHA105.The growth of the strain EHA105 with 48 h continuous culture was observed based on which the growth curve was plotted.At the same time,different concentrations of CaCl2 and different temperatures in heat-shocking during the transformation were tested in preparing the competent cells of EHA105.The number of positive transformants was determined and the factors affecting introduction of exogenous DNA into the strain EHA105 by using the freeze-thaw method were identified.When the OD600 value ranged from 1.0 to 1.5,the strain EHA105 was found at the logarithmic growth phase and had the highest vitality.No significant difference was observed in the transformation rates of competent cells prepared with the CaCl2 at the concentration of between 6 mmol·L-1 and 10 mmol·L-1,but the best transformation rate was 5.322×106·μg-1 at 10 mmol·L-1 CaCl2.No significant difference was found in transformation rates at the heat-shock temperatures from 20 ℃ to 37 ℃ during transformation,but the best transformation rate（5.550×106·μg-1） was achieved at 37 ℃.The results provide a reference for improving the transformation efficiency of A.tumefaciens EHA105 competent cells.
2012, 3(1): 28-31.
doi: 10.15886/j.cnki.rdswxb.2012.01.002
Abstract:
Nine high producing lipase strains were isolated from rich oil soil at canteens,sea sludge and garages from Haikou in hot summer.All these strains were Gram-negative and rod-shaped single cells and investigated in terms of morphology,growth and 16S rRNA gene sequences.All colonies of these strains were blue green on the plate under light microscope,indicating that the strains might secrete pigments of such color.The optimal growth conditions for these strains were pH7.0 at the temperature of above 42 ℃.All the strains had completely the same 16S rRNA gene sequences as Pseudomonas aeruginosa,and hence are identified as P.aeruginosa.
Nine high producing lipase strains were isolated from rich oil soil at canteens,sea sludge and garages from Haikou in hot summer.All these strains were Gram-negative and rod-shaped single cells and investigated in terms of morphology,growth and 16S rRNA gene sequences.All colonies of these strains were blue green on the plate under light microscope,indicating that the strains might secrete pigments of such color.The optimal growth conditions for these strains were pH7.0 at the temperature of above 42 ℃.All the strains had completely the same 16S rRNA gene sequences as Pseudomonas aeruginosa,and hence are identified as P.aeruginosa.
2012, 3(1): 32-37,41.
doi: 10.15886/j.cnki.rdswxb.2012.01.013
Abstract:
A total of 138 root endophytic actinomycete strains were successfully isolated using 1/10ATCC 172 medium from the roots of 18 mangrove plants and 3 semi-mangrove plants in Hainan Province.Analysis of 16S rRNA gene sequences of these isolates showed that the isolates belonged to members of the genera Jishengella,Micromonospora and Streptomycetes.Bioactivity tests were carried out on all the isolated endophytic actinomycete fermentation liquids.Of all the isolates forty strains showed citotoxities to hepatocarcinoma cell line SMMC-7721 cell,and twenty seven strains were active against methicillin-resistant Staphylococcus aureus 9551（MRSA）.The strains isolated from the mangroves showed no bioactivity against Candida albicans ATCC 10231.Sodium chloride tolerance test for 88 isolates indicated that 77 isolates were halo-tolerant or halophilic,2 isolates of which exhibited the highest tolerance to ρ(NaCl）=150 g·L-1 and 54 isolates grew well on the medium containing ρ(NaCl）=33 g·L-1.
A total of 138 root endophytic actinomycete strains were successfully isolated using 1/10ATCC 172 medium from the roots of 18 mangrove plants and 3 semi-mangrove plants in Hainan Province.Analysis of 16S rRNA gene sequences of these isolates showed that the isolates belonged to members of the genera Jishengella,Micromonospora and Streptomycetes.Bioactivity tests were carried out on all the isolated endophytic actinomycete fermentation liquids.Of all the isolates forty strains showed citotoxities to hepatocarcinoma cell line SMMC-7721 cell,and twenty seven strains were active against methicillin-resistant Staphylococcus aureus 9551（MRSA）.The strains isolated from the mangroves showed no bioactivity against Candida albicans ATCC 10231.Sodium chloride tolerance test for 88 isolates indicated that 77 isolates were halo-tolerant or halophilic,2 isolates of which exhibited the highest tolerance to ρ(NaCl）=150 g·L-1 and 54 isolates grew well on the medium containing ρ(NaCl）=33 g·L-1.
2012, 3(1): 38-41.
doi: 10.15886/j.cnki.rdswxb.2012.01.010
Abstract:
Four chemical reagents,jasmonic acid（JA）,ethrel,Aspirin and tryptophan,were used as exogenous hormones to treat pot plants of Catharanthus roseus grown in green house to determine the contents of medicinal components,alkaloids,in C.roseus leaves.The pot plants at the age of 2 and 5 months were treated with the reagents at different concentrations.Two days after treatment,the contents of catharanthine,vinblastine and vindoline in leaves were determined by using HPLC.All the reagents under trial obviously improved the accumulation of indole alkaloids including catharanthine and vinblastine in the leaves of C.roseus,and the optimum treatment concentrations of these reagents were determined.These reagents apparently promote the accumulation of total indole alkoloids in the leaves of C.roseus.
Four chemical reagents,jasmonic acid（JA）,ethrel,Aspirin and tryptophan,were used as exogenous hormones to treat pot plants of Catharanthus roseus grown in green house to determine the contents of medicinal components,alkaloids,in C.roseus leaves.The pot plants at the age of 2 and 5 months were treated with the reagents at different concentrations.Two days after treatment,the contents of catharanthine,vinblastine and vindoline in leaves were determined by using HPLC.All the reagents under trial obviously improved the accumulation of indole alkaloids including catharanthine and vinblastine in the leaves of C.roseus,and the optimum treatment concentrations of these reagents were determined.These reagents apparently promote the accumulation of total indole alkoloids in the leaves of C.roseus.
2012, 3(1): 42-50.
doi: 10.15886/j.cnki.rdswxb.2012.01.014
Abstract:
In order to analyze and control the quality of the rubber plantation flux observation data,the FSAM model（Flux-source Area Model） was used to calculate flux footprint and source areas according to the continuous flux measurement with the open-path eddy covariance system on the 50 m tower of the Ministry of Agriculture Danzhou Key Field Station of Observation and Research for Tropical Agricultural Resources and Environments from Jan.1 to Dec.31,2010.The spatial representative of flux measurement of the rubber plantations in Hainan Island,the south of China,was explained.Source areas of rubber plantation were found smaller under the unstable than under the stable atmospheric stratification.The source areas were larger in the growing season than in the dormant season at the same contribution level for the stable stratification,but they were smaller under the unstable stratification.In the main wind direction of 110°—250°,the upwind range of source areas of the rubber plantation was 100—758 m,and the vertical upwind range was-251—251 m at a 80% contribution level under the unstable stratification in the growing season,whereas the upwind and vertical upwind ranges were slightly larger than those under the unstable stratification in the dormant season.The upwind and vertical upwind ranges of the source areas were 173—1858 m and-534—534 m,respectively under the stable stratification in the growing season,and they were slightly smaller than those under the stable stratification in the dormant season.In the wind directions of 0°—110° and 250°—360°,the upwind range of the source areas was larger under the stable stratification of the rubber plantation than but similar to those in the prevailing wind direction under the unstable stratification.
In order to analyze and control the quality of the rubber plantation flux observation data,the FSAM model（Flux-source Area Model） was used to calculate flux footprint and source areas according to the continuous flux measurement with the open-path eddy covariance system on the 50 m tower of the Ministry of Agriculture Danzhou Key Field Station of Observation and Research for Tropical Agricultural Resources and Environments from Jan.1 to Dec.31,2010.The spatial representative of flux measurement of the rubber plantations in Hainan Island,the south of China,was explained.Source areas of rubber plantation were found smaller under the unstable than under the stable atmospheric stratification.The source areas were larger in the growing season than in the dormant season at the same contribution level for the stable stratification,but they were smaller under the unstable stratification.In the main wind direction of 110°—250°,the upwind range of source areas of the rubber plantation was 100—758 m,and the vertical upwind range was-251—251 m at a 80% contribution level under the unstable stratification in the growing season,whereas the upwind and vertical upwind ranges were slightly larger than those under the unstable stratification in the dormant season.The upwind and vertical upwind ranges of the source areas were 173—1858 m and-534—534 m,respectively under the stable stratification in the growing season,and they were slightly smaller than those under the stable stratification in the dormant season.In the wind directions of 0°—110° and 250°—360°,the upwind range of the source areas was larger under the stable stratification of the rubber plantation than but similar to those in the prevailing wind direction under the unstable stratification.
2012, 3(1): 51-55.
doi: 10.15886/j.cnki.rdswxb.2012.01.015
Abstract:
This paper analyzes the changes in rubber tree planting density,number of growing trees per ha,number of trees available for tapping,percentage of effective tapping trees,and types of available trees in the rubber plantation based on the recent data collected from the rubber tree production in China.It also analyzes the effect of available tapping trees per unit area on the land output capacity in the rubber plantation and its reasons,and makes some suggestions on how to improve the number of available trees under tapping in rubber plantations.
This paper analyzes the changes in rubber tree planting density,number of growing trees per ha,number of trees available for tapping,percentage of effective tapping trees,and types of available trees in the rubber plantation based on the recent data collected from the rubber tree production in China.It also analyzes the effect of available tapping trees per unit area on the land output capacity in the rubber plantation and its reasons,and makes some suggestions on how to improve the number of available trees under tapping in rubber plantations.
2012, 3(1): 56-58.
doi: 10.15886/j.cnki.rdswxb.2012.01.011
Abstract:
Two-line hybrid rice parents of combination Y58S/9311 were sown by stages in the field in 2010 to observe their growth characteristics in Haikou,Hainan province.The results showed that the duration from seeding to heading（DSH） of the paternal line 9311 is 93—113 days in different sowing stage,and tends to be shortened gradually with the delay of sowing dates,and that the DSH of the maternal line Y58S is 85—98 days.Regression analysis between the cumulative temperature and the DSH showed that the DSH of the maternal line was significantly correlated with the cumulative temperature,while that of the paternal line was not significantly correlated with the cumulative temperature.
Two-line hybrid rice parents of combination Y58S/9311 were sown by stages in the field in 2010 to observe their growth characteristics in Haikou,Hainan province.The results showed that the duration from seeding to heading（DSH） of the paternal line 9311 is 93—113 days in different sowing stage,and tends to be shortened gradually with the delay of sowing dates,and that the DSH of the maternal line Y58S is 85—98 days.Regression analysis between the cumulative temperature and the DSH showed that the DSH of the maternal line was significantly correlated with the cumulative temperature,while that of the paternal line was not significantly correlated with the cumulative temperature.
2012, 3(1): 59-61.
doi: 10.15886/j.cnki.rdswxb.2012.01.012
Abstract:
Guifei mango fruit（Mangifera indica） were treated with BTH（100,200,300 mg·L-1）,carbendazim and inoculation to observe the change of total polyphenol content in mango peel.The mango fruits treated contained obviously higher total polyphenols in mango peel at 72h of treatment or the stage of yellow-ripening than those of the control.At 72h the mango fruit treated with BTH at the concentrations of 100 mg·L-1 and 200 mg·L-1 had higher total poyphenols content,1.8 and 1.7 times higher than that of the control,respectively.At the stage of yellow ripening,the mango fruit treated with carbendazim and inoculation contained higher total polyphenols than other treatments,which were 2.1 and 2.0 times higher than those of the control,respectively.
Guifei mango fruit（Mangifera indica） were treated with BTH（100,200,300 mg·L-1）,carbendazim and inoculation to observe the change of total polyphenol content in mango peel.The mango fruits treated contained obviously higher total polyphenols in mango peel at 72h of treatment or the stage of yellow-ripening than those of the control.At 72h the mango fruit treated with BTH at the concentrations of 100 mg·L-1 and 200 mg·L-1 had higher total poyphenols content,1.8 and 1.7 times higher than that of the control,respectively.At the stage of yellow ripening,the mango fruit treated with carbendazim and inoculation contained higher total polyphenols than other treatments,which were 2.1 and 2.0 times higher than those of the control,respectively.
2012, 3(1): 62-65,68.
doi: 10.15886/j.cnki.rdswxb.2012.01.007
Abstract:
Banana vitroplants of 4—5 leaves were inoculated in different ways with two biocontrol bacteria Bacillus subtilis strains A5-6 and C10-1 and the banana Fusarium wilt pathogen（Foc4） to observe their changes of polyphenol oxidase（PPO）,peroxidase（POD） and phenylalanine ammonialyase（PAL） activities in leaves,which are related to plant tolerance to the disease.The PPO,POD and PAL activities in the leaves of the banana plants were determined by using the physiological and biochemical methods.The banana plants inoculated with the strains A5-6 and C10-1 separately showed higher leaf PPO,POD and PAL activities than those inoculated with the sterile water control,and the banana plants inoculated with mixture of the biocontrol bacteria and Foc4 pathogen had higher leaf PPO,POD and PAL activities than those inoculated with Foc4 alone.
Banana vitroplants of 4—5 leaves were inoculated in different ways with two biocontrol bacteria Bacillus subtilis strains A5-6 and C10-1 and the banana Fusarium wilt pathogen（Foc4） to observe their changes of polyphenol oxidase（PPO）,peroxidase（POD） and phenylalanine ammonialyase（PAL） activities in leaves,which are related to plant tolerance to the disease.The PPO,POD and PAL activities in the leaves of the banana plants were determined by using the physiological and biochemical methods.The banana plants inoculated with the strains A5-6 and C10-1 separately showed higher leaf PPO,POD and PAL activities than those inoculated with the sterile water control,and the banana plants inoculated with mixture of the biocontrol bacteria and Foc4 pathogen had higher leaf PPO,POD and PAL activities than those inoculated with Foc4 alone.
2012, 3(1): 66-68.
doi: 10.15886/j.cnki.rdswxb.2012.01.008
Abstract:
Chelonus formosanus Sonan of Chelonus Panzer was recorded in Hainan Island,China,and its specimens with the description,distribution,host records and characteristic graph are placed available in the Institute of Agricultural Environment and Plant Protection,Hainan Academy of Agricultural Sciences.
Chelonus formosanus Sonan of Chelonus Panzer was recorded in Hainan Island,China,and its specimens with the description,distribution,host records and characteristic graph are placed available in the Institute of Agricultural Environment and Plant Protection,Hainan Academy of Agricultural Sciences.
2012, 3(1): 69-72.
doi: 10.15886/j.cnki.rdswxb.2012.01.009
Abstract:
Crude extracts from seeds of Jatropha curcas L.were obtained with ethanol,butanol,ethyl acetate,chloroform and petroleum ether by using the impregnation method,and the toxicity of each crude extract against two pest insects,Plutella xylostella and Musca domestica,was determined by the tag method and the stomach poison method,seperately.The results show that the five extracts of seeds all demonstrated high activities against these two pest insects.Of the five extracts the ethyl acetate extract showed the best insecticidal effect on P.xylostella when treated at the rate of 50 g·L-1.P.xylostella had a corrected mortality of 93.6% when treated with the ethyl acetate extract for 48 h but had the lowest corrected mortality（78.9%） when treated with petroleum ether extract.M.domestica had the highest corrected mortality（100%） when exposed to the ethanol extract（10 g·L-1） for 48h,but had the lowest corrected mortality（58.3%） when treated with the petroleum ether extract.
Crude extracts from seeds of Jatropha curcas L.were obtained with ethanol,butanol,ethyl acetate,chloroform and petroleum ether by using the impregnation method,and the toxicity of each crude extract against two pest insects,Plutella xylostella and Musca domestica,was determined by the tag method and the stomach poison method,seperately.The results show that the five extracts of seeds all demonstrated high activities against these two pest insects.Of the five extracts the ethyl acetate extract showed the best insecticidal effect on P.xylostella when treated at the rate of 50 g·L-1.P.xylostella had a corrected mortality of 93.6% when treated with the ethyl acetate extract for 48 h but had the lowest corrected mortality（78.9%） when treated with petroleum ether extract.M.domestica had the highest corrected mortality（100%） when exposed to the ethanol extract（10 g·L-1） for 48h,but had the lowest corrected mortality（58.3%） when treated with the petroleum ether extract.
2012, 3(1): 73-77.
doi: 10.15886/j.cnki.rdswxb.2012.01.003
Abstract:
Birds in the mangrove wetland at Dongzhai Harbor,Hainan were investigated,and their diversity and habitats were analyzed by using the line transect method from 2009 to 2010.The results shows that 11 orders,26 families and 65 species of birds have been spotted,numbering 24 531.The water birds are particularly plentiful and 41 species spotted,accounting for 63% of all the spotted species.The diversity and number of water birds show a significant seasonal variation,with more species and number in the wintering period than in breeding period.The species composition and diversity of birds in different habitats also differ significantly with season.
Birds in the mangrove wetland at Dongzhai Harbor,Hainan were investigated,and their diversity and habitats were analyzed by using the line transect method from 2009 to 2010.The results shows that 11 orders,26 families and 65 species of birds have been spotted,numbering 24 531.The water birds are particularly plentiful and 41 species spotted,accounting for 63% of all the spotted species.The diversity and number of water birds show a significant seasonal variation,with more species and number in the wintering period than in breeding period.The species composition and diversity of birds in different habitats also differ significantly with season.
2012, 3(1): 78-82.
doi: 10.15886/j.cnki.rdswxb.2012.01.005
Abstract:
An index system for assessment of sustainable agricultural development capacity in Hainan Province was developed according to the construction principles and selection methods of a given index system,and the index weight was defined based on the coefficient of variance.The system was run with the data from the year 2000 to 2009 to evaluate the capacity of sustainable agricultural development in Hainan Province.The results show that from the year 2000 to 2009 the agricultural systems for Hainan Province generally took on a good development trend,but the sustainability of the rural social subsystem,the agricultural resources subsystem and the environment subsystem is unstable.These vulnerable subsystems are suggested to improve with more efforts.
An index system for assessment of sustainable agricultural development capacity in Hainan Province was developed according to the construction principles and selection methods of a given index system,and the index weight was defined based on the coefficient of variance.The system was run with the data from the year 2000 to 2009 to evaluate the capacity of sustainable agricultural development in Hainan Province.The results show that from the year 2000 to 2009 the agricultural systems for Hainan Province generally took on a good development trend,but the sustainability of the rural social subsystem,the agricultural resources subsystem and the environment subsystem is unstable.These vulnerable subsystems are suggested to improve with more efforts.
2012, 3(1): 83-87.
doi: 10.15886/j.cnki.rdswxb.2012.01.019
Abstract:
Juvenile Hemifusus tuba were net cage cultured at different stocking densities（10,20,30,40,50 shells/cage） to select optimum stocking density and then cultured in suspended net cages in Yunbo bay,Yangjiang city,Guangdong Province.The juvenile H.tuba reared under different stock densities for 60 days in natural conditions showed an exponential growth in shell height and body weight.The coefficients of variance（CVs） for the growth of the juvenile H.tuba in all the treatments except D1（10 juveniles/cage） were significantly reduced.The juvenile H.tuba grew significantly different among the all the treatments,but fastest in the treatments D2（20 juveniles/cage） and D3（30 juveniles/cage）.The growth rate,specific growth rate（SGR） and daily weight growth（DWG） of the juvenile H.tuba decreased with the increase of the stocking densities.The SGR had a significant cubic polynomial regression with the stocking density（SGR=0.857 3+0.153 2D-0.005 1D2+0.000 05D3,R2=0.999 1）.Juvenile H.tuba in the treatments D2 and D3 grew the fastest in all stocking densities,but the D3（30 juveniles/cage） was the optimum stocking density and selected for net cage culture when the rearing cost and management were considered.The juvenile H.tuba were cultured in suspended net cages at the stocking density of 30 juveniles/cage in Yunbo bay.After 100 days of suspended net cage culture of the juveniles,the shell height increased by 34.7%,and body weight by 157.4%.The DWG and daily height growth（DHG） were 0.18 mm·d and 0.173 g·d,respectively.The survival rate was 98%.The suspended net cage culture is found fit for culture of juvenile H.tuba.
Juvenile Hemifusus tuba were net cage cultured at different stocking densities（10,20,30,40,50 shells/cage） to select optimum stocking density and then cultured in suspended net cages in Yunbo bay,Yangjiang city,Guangdong Province.The juvenile H.tuba reared under different stock densities for 60 days in natural conditions showed an exponential growth in shell height and body weight.The coefficients of variance（CVs） for the growth of the juvenile H.tuba in all the treatments except D1（10 juveniles/cage） were significantly reduced.The juvenile H.tuba grew significantly different among the all the treatments,but fastest in the treatments D2（20 juveniles/cage） and D3（30 juveniles/cage）.The growth rate,specific growth rate（SGR） and daily weight growth（DWG） of the juvenile H.tuba decreased with the increase of the stocking densities.The SGR had a significant cubic polynomial regression with the stocking density（SGR=0.857 3+0.153 2D-0.005 1D2+0.000 05D3,R2=0.999 1）.Juvenile H.tuba in the treatments D2 and D3 grew the fastest in all stocking densities,but the D3（30 juveniles/cage） was the optimum stocking density and selected for net cage culture when the rearing cost and management were considered.The juvenile H.tuba were cultured in suspended net cages at the stocking density of 30 juveniles/cage in Yunbo bay.After 100 days of suspended net cage culture of the juveniles,the shell height increased by 34.7%,and body weight by 157.4%.The DWG and daily height growth（DHG） were 0.18 mm·d and 0.173 g·d,respectively.The survival rate was 98%.The suspended net cage culture is found fit for culture of juvenile H.tuba.
2012, 3(1): 88-91.
doi: 10.15886/j.cnki.rdswxb.2012.01.020
Abstract:
Larval and juvenile Chlamys nobilis were reared in the suspended culture socks caged with 0.8 cm mesh polypropylene nets to develop a suspended sock culture method in Sanya,Hainan,China.The experiment group was found to have lower shell height growth rate and survival rate than the control group at the larval stage.In the artificial raft suspended culture the experiment group grew slightly lower than the control group but had a higher survival rate than the control group.Therefore,the suspended sock culture is not fit for larval C.nobilis but for the juveniles.This method can be widely used for culture of C.nobilis at the juvenile stage.
Larval and juvenile Chlamys nobilis were reared in the suspended culture socks caged with 0.8 cm mesh polypropylene nets to develop a suspended sock culture method in Sanya,Hainan,China.The experiment group was found to have lower shell height growth rate and survival rate than the control group at the larval stage.In the artificial raft suspended culture the experiment group grew slightly lower than the control group but had a higher survival rate than the control group.Therefore,the suspended sock culture is not fit for larval C.nobilis but for the juveniles.This method can be widely used for culture of C.nobilis at the juvenile stage.
2012, 3(1): 92-98.
doi: 10.15886/j.cnki.rdswxb.2012.01.004
Abstract:
This paper reviews the advances in research of synthetic genes and regulator genes involved in the anthocyanin biological synthesis process as well as in genetic engineering in regulating the anthocyanin biological synthesis.Anthocyanin biological synthesis process of plants belongs to the secondary metabolic pathway,regulates the expression of key enzymes involved in the pathway,and could hence lead to a reduced or increased yield of target compound.Genetic improvement of plants may be realized through modifying the secondary metabolic process.Anthocyanin accumulation helps the plants to act against the UV radiation,insects and fungi.Further study on the defense molecular mechanism of the anthocyanin facilitates breeding of new plant cultivars with resistance to diseases and adversities.
This paper reviews the advances in research of synthetic genes and regulator genes involved in the anthocyanin biological synthesis process as well as in genetic engineering in regulating the anthocyanin biological synthesis.Anthocyanin biological synthesis process of plants belongs to the secondary metabolic pathway,regulates the expression of key enzymes involved in the pathway,and could hence lead to a reduced or increased yield of target compound.Genetic improvement of plants may be realized through modifying the secondary metabolic process.Anthocyanin accumulation helps the plants to act against the UV radiation,insects and fungi.Further study on the defense molecular mechanism of the anthocyanin facilitates breeding of new plant cultivars with resistance to diseases and adversities.
Email alert
RSS