2017 Vol. 8, No. 4
Abstract
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2017, 8(4): 377-382.
doi: 10.15886/j.cnki.rdswxb.2017.04.001
Abstract:
In order to investigate the mechanism of chondroitin sulfate synthase 1（ ChSy-1） participating in biomineralization in the pearl oyster Pinctada fucata,we performed tissue distribution experiment,shell notching experiment and RNA interference test. Results showed that ChSy-1 gene was expressed in different parts of the mantle of P. fucata,,highly in the edge of the mantle. At the different developmental stages,the expression of ChSy-1 was higher at the polar body phase,2-cell stage and 32-cell stage. The results of shell notching experiment showed that the expression of ChSy-1 gene increased significantly after 48 and 72 hours,and that the expression level of ChSy-1 also increased significantly after knockout of BMP2 gene,which is consistent with the mechanism by which ChSy-1 plays a negative regulatory role in the BMP signaling pathway. This study shows that ChSy-1 plays an important role in the biomineralization of P. fucata,which provides important information for the characterization of ChSy-1 in the biomineralization of P. fucata.
In order to investigate the mechanism of chondroitin sulfate synthase 1（ ChSy-1） participating in biomineralization in the pearl oyster Pinctada fucata,we performed tissue distribution experiment,shell notching experiment and RNA interference test. Results showed that ChSy-1 gene was expressed in different parts of the mantle of P. fucata,,highly in the edge of the mantle. At the different developmental stages,the expression of ChSy-1 was higher at the polar body phase,2-cell stage and 32-cell stage. The results of shell notching experiment showed that the expression of ChSy-1 gene increased significantly after 48 and 72 hours,and that the expression level of ChSy-1 also increased significantly after knockout of BMP2 gene,which is consistent with the mechanism by which ChSy-1 plays a negative regulatory role in the BMP signaling pathway. This study shows that ChSy-1 plays an important role in the biomineralization of P. fucata,which provides important information for the characterization of ChSy-1 in the biomineralization of P. fucata.
2017, 8(4): 383-389.
doi: 10.15886/j.cnki.rdswxb.2017.04.002
Abstract:
A new model for intermediate culture of Trachinotus ovatus fingerlings in large cage was designed,and the main technical parameters were determined by experiment. This culture model included three stages of culture:primary,secondary and tertiary,and the initial size of Trachinotus ovatus fingerlings were 2. 9-3. 2 cm. For the primary,secondary and tertiary culture the stocking densities were 280-300 ind·m-3,150-180 ind·m-3 and 120-150 ind·m-3,respectively,and the net mesh size was 2 a = 1. 2 cm,2. 0 cm and 3. 0 cm,respectively.The fingerlings were selected by sieving for the secondary culture when they were 4. 4 cm or more long and accounted for（ 40 ±2） % of the total. Likewise,the fingerlings of 5. 8 cm or more were sieved and selected for tertiary culture when they were（ 90 ±2） % of the total. The fingerlings were sieved for adult fish culture when they were7. 2 cm or more long and made up（ 90 ±2） % of the total. When cultured in this model,the fingerlings had a survival rate of more than 85%,and the number of fingerlings with the body length between 7. 2 cm and 8. 2 cm accounted for more than 85%. Compared with the traditional culture,this culture model had a higher survival rate by above 10%,reducing the production cost effectively and increasing the profit.
A new model for intermediate culture of Trachinotus ovatus fingerlings in large cage was designed,and the main technical parameters were determined by experiment. This culture model included three stages of culture:primary,secondary and tertiary,and the initial size of Trachinotus ovatus fingerlings were 2. 9-3. 2 cm. For the primary,secondary and tertiary culture the stocking densities were 280-300 ind·m-3,150-180 ind·m-3 and 120-150 ind·m-3,respectively,and the net mesh size was 2 a = 1. 2 cm,2. 0 cm and 3. 0 cm,respectively.The fingerlings were selected by sieving for the secondary culture when they were 4. 4 cm or more long and accounted for（ 40 ±2） % of the total. Likewise,the fingerlings of 5. 8 cm or more were sieved and selected for tertiary culture when they were（ 90 ±2） % of the total. The fingerlings were sieved for adult fish culture when they were7. 2 cm or more long and made up（ 90 ±2） % of the total. When cultured in this model,the fingerlings had a survival rate of more than 85%,and the number of fingerlings with the body length between 7. 2 cm and 8. 2 cm accounted for more than 85%. Compared with the traditional culture,this culture model had a higher survival rate by above 10%,reducing the production cost effectively and increasing the profit.
2017, 8(4): 390-398.
doi: 10.15886/j.cnki.rdswxb.2017.04.003
Abstract:
Zooplankton communities in the shellfish-culture area and its adjacent non-culture area in Li’an Lagoon in the south of Hainan Island were observed to analyze their short-term temporal variation in dry season,and were found to have high abundance,species richness,significant dominant species and low evenness. In the zooplankton communities were identified 104 species of zooplankton and 14 species of planktonic larvae,which were under 6 phyla and 76 genera. The total abundance ranged from 114 ind·L-1 to 735 ind·L-1,including58%-77% protozoa,18%-30% copepods,and 1%-13% tunicate. The dominant species were mainly Acrocalanus gibber,Oithona brevicornis,Oikopleura（ vexillaria） dioica Harpacticoida,Favella ehrenbergi,Strombidinopsis acuminatum,Tintinnopsis lobiancoi,Globigerina quinqueloba and Helicostomella longa. The dominant species and dominance of the zooplankton showed temporal variation. The temporal pattern of the zooplankton in the shellfish culture area was similar to that in the adjacent non-culture area,but higher average abundance was observed in the non-culture area in the early month of the observation. Analysis of relationship between zooplankton communities and environmental factors showed that temperature,salinity and chlorophyll a were highly correlated to the zooplankton communities. The results demonstrated that apparent variations occurred in the community composition and abundance of the zooplankton even within one month in Li’an Lagoon. So it should be cautious to adopt the data from one single sampling time to represent long-term data in marine environmental research and monitoring.
Zooplankton communities in the shellfish-culture area and its adjacent non-culture area in Li’an Lagoon in the south of Hainan Island were observed to analyze their short-term temporal variation in dry season,and were found to have high abundance,species richness,significant dominant species and low evenness. In the zooplankton communities were identified 104 species of zooplankton and 14 species of planktonic larvae,which were under 6 phyla and 76 genera. The total abundance ranged from 114 ind·L-1 to 735 ind·L-1,including58%-77% protozoa,18%-30% copepods,and 1%-13% tunicate. The dominant species were mainly Acrocalanus gibber,Oithona brevicornis,Oikopleura（ vexillaria） dioica Harpacticoida,Favella ehrenbergi,Strombidinopsis acuminatum,Tintinnopsis lobiancoi,Globigerina quinqueloba and Helicostomella longa. The dominant species and dominance of the zooplankton showed temporal variation. The temporal pattern of the zooplankton in the shellfish culture area was similar to that in the adjacent non-culture area,but higher average abundance was observed in the non-culture area in the early month of the observation. Analysis of relationship between zooplankton communities and environmental factors showed that temperature,salinity and chlorophyll a were highly correlated to the zooplankton communities. The results demonstrated that apparent variations occurred in the community composition and abundance of the zooplankton even within one month in Li’an Lagoon. So it should be cautious to adopt the data from one single sampling time to represent long-term data in marine environmental research and monitoring.
2017, 8(4): 399-403.
doi: 10.15886/j.cnki.rdswxb.2017.04.004
Abstract:
Corals have a very high requirement for water quality,and high contents of nitrogen and phosphorus give adverse impact on their survival and breeding. Nutrient concentrations are usually very high in culture of corals. Ethanol was used as an external carbon source and added into the water for growing corals to analyze the effect of ethanol on improvement of the water quality in the coral culture system. The analysis showed the external carbon source had prominent influence on some of the important water quality indexes. The water in culture of corals was found to decrease its nitrate and nitrite contents to a level lower than detection limits 1-2 days after added with ethanol; the ammonium salt content was decreased to lower than detection limits 4 days after ethanol addition; the phosphate content underwent a downward trend within 1-4 days after ethanol addition,the lowest（ 0. 14 μmol·L-1） at day 1 after ethanol addition,and recovering to the initial level at day 5; the contents of calcium and magnesium ions and alkalinity maintained at a certain range after the addition of ethanol,but were higher than those before ethanol addition. These results demonstrated that the external carbon source reduced evidently inorganic nitrogen content in the water for coral culture and maintained its contents of calcium and magnesium ions and alkalinity,which modulates the water quality of coral system at the optimal level.
Corals have a very high requirement for water quality,and high contents of nitrogen and phosphorus give adverse impact on their survival and breeding. Nutrient concentrations are usually very high in culture of corals. Ethanol was used as an external carbon source and added into the water for growing corals to analyze the effect of ethanol on improvement of the water quality in the coral culture system. The analysis showed the external carbon source had prominent influence on some of the important water quality indexes. The water in culture of corals was found to decrease its nitrate and nitrite contents to a level lower than detection limits 1-2 days after added with ethanol; the ammonium salt content was decreased to lower than detection limits 4 days after ethanol addition; the phosphate content underwent a downward trend within 1-4 days after ethanol addition,the lowest（ 0. 14 μmol·L-1） at day 1 after ethanol addition,and recovering to the initial level at day 5; the contents of calcium and magnesium ions and alkalinity maintained at a certain range after the addition of ethanol,but were higher than those before ethanol addition. These results demonstrated that the external carbon source reduced evidently inorganic nitrogen content in the water for coral culture and maintained its contents of calcium and magnesium ions and alkalinity,which modulates the water quality of coral system at the optimal level.
2017, 8(4): 404-408,423.
doi: 10.15886/j.cnki.rdswxb.2017.04.005
Abstract:
An experiment was carried out to reduce the number of the coliform group and the total colony count in Crassostrea rivularis cultured in sea water to ensure food safety. Sea water used for culture of C. rivularis was disinfected with ozone at concentrations of 0. 4,0. 8 and 1. 2 mg·L-1 to select an appropriate ozone concentration for a combinedozone-ultraviolet system used for depuration of the seawater. The seawater was disinfected under the combined ozone-ultraviolet system for 24 hrs at different temperatures,seawater exchange rate,and ratio of shellfish to water,and used to rear C. rivularis to find out a seawater depuration method for C. rivularis. The results indicated that the sea water when depurated for 24 hrs with ozone at a concentration of 0. 8 mg·L-1,a temperature at 25 ℃,a ratio of shellfish to water at 1∶ 15,salinity at 8 and an water exchange rate at 4 times/h,had a better depuration rate against the coliform group of bacteria in Crassostrea rivularis. This indicates that the combined ozone-ultraviolet system is effective to disinfect the coliform group in Crassostrea rivularis.
An experiment was carried out to reduce the number of the coliform group and the total colony count in Crassostrea rivularis cultured in sea water to ensure food safety. Sea water used for culture of C. rivularis was disinfected with ozone at concentrations of 0. 4,0. 8 and 1. 2 mg·L-1 to select an appropriate ozone concentration for a combinedozone-ultraviolet system used for depuration of the seawater. The seawater was disinfected under the combined ozone-ultraviolet system for 24 hrs at different temperatures,seawater exchange rate,and ratio of shellfish to water,and used to rear C. rivularis to find out a seawater depuration method for C. rivularis. The results indicated that the sea water when depurated for 24 hrs with ozone at a concentration of 0. 8 mg·L-1,a temperature at 25 ℃,a ratio of shellfish to water at 1∶ 15,salinity at 8 and an water exchange rate at 4 times/h,had a better depuration rate against the coliform group of bacteria in Crassostrea rivularis. This indicates that the combined ozone-ultraviolet system is effective to disinfect the coliform group in Crassostrea rivularis.
2017, 8(4): 409-414.
doi: 10.15886/j.cnki.rdswxb.2017.04.006
Abstract:
The gene MeHDS09 was cloned from cassava to analyze its structure and functions in tissue cultured plants under different abiotic stresses. MeHDS09 was isolated from cassava plant using RT-PCR and had 2 151 bp open reading frame encoding 716 amino acids according to the transcriptome data and genome-wide public sequences on cassava. The MeHDS09 encoded protein was 81. 2 k D in molecular weight,and did not contain the signal peptide site. Subcellular localization prediction showed that MeHDS09 contained mitochondrial targeting peptide and was mainly localized in mitochondrion. Comparison of sequences similarity with reported genes sequences in Genbank showed that MeHDS09 might have higher homology with Protein 2 in soybean,which was related to enhancement of plant disease resistance. The promoter sequence analysis showed that the upstream promoter sequence of the MeHDS09 contained not only promoter core elements but also hormone responsive elements in response to disease resistance and hormones. This indicated that the expression of MeHDS09 might be influenced by the external environment factors. Further analysis with qRP-PCR showed that the MeHDS09 was not sensitive in response to GA/IAA,and that the cold,ABA and JA treatments induced significant expression of MeHDS09 in cassava,while the hot and SA treatments inhibited obviously expression of the MeHDS09. The results revealed that MeHDS09 might play a role in resistance to abiotic stresses in cassava,such as low temperature.
The gene MeHDS09 was cloned from cassava to analyze its structure and functions in tissue cultured plants under different abiotic stresses. MeHDS09 was isolated from cassava plant using RT-PCR and had 2 151 bp open reading frame encoding 716 amino acids according to the transcriptome data and genome-wide public sequences on cassava. The MeHDS09 encoded protein was 81. 2 k D in molecular weight,and did not contain the signal peptide site. Subcellular localization prediction showed that MeHDS09 contained mitochondrial targeting peptide and was mainly localized in mitochondrion. Comparison of sequences similarity with reported genes sequences in Genbank showed that MeHDS09 might have higher homology with Protein 2 in soybean,which was related to enhancement of plant disease resistance. The promoter sequence analysis showed that the upstream promoter sequence of the MeHDS09 contained not only promoter core elements but also hormone responsive elements in response to disease resistance and hormones. This indicated that the expression of MeHDS09 might be influenced by the external environment factors. Further analysis with qRP-PCR showed that the MeHDS09 was not sensitive in response to GA/IAA,and that the cold,ABA and JA treatments induced significant expression of MeHDS09 in cassava,while the hot and SA treatments inhibited obviously expression of the MeHDS09. The results revealed that MeHDS09 might play a role in resistance to abiotic stresses in cassava,such as low temperature.
2017, 8(4): 415-418.
doi: 10.15886/j.cnki.rdswxb.2017.04.007
Abstract:
Eukaryotic translation initiation factor 4 e（ eIF4E） is a necessary factor for many viruses infecting plants. The plant expression vectors of Cp-eIF4E and Cp-eIFiso4E were constructed,fused with green fluorescent protein（ GFP）,and transformed into the protoplasts of tobacco leaf to study the subcellular localization of papaya eIF4E family. The results showed that Cp-eIF4E and Cp-e IFiso4 E were expressed in the cytoplasm and nucleus. This study would lay a foundation for further study of the interactions between the papaya eIF4E family proteins and viruses,and their functions in virus infection.
Eukaryotic translation initiation factor 4 e（ eIF4E） is a necessary factor for many viruses infecting plants. The plant expression vectors of Cp-eIF4E and Cp-eIFiso4E were constructed,fused with green fluorescent protein（ GFP）,and transformed into the protoplasts of tobacco leaf to study the subcellular localization of papaya eIF4E family. The results showed that Cp-eIF4E and Cp-e IFiso4 E were expressed in the cytoplasm and nucleus. This study would lay a foundation for further study of the interactions between the papaya eIF4E family proteins and viruses,and their functions in virus infection.
2017, 8(4): 419-423.
doi: 10.15886/j.cnki.rdswxb.2017.04.008
Abstract:
Young shoots of the stem of Bitter Leaf（ Vernonia amygdalina Del） were used as explants and cultured in the 1/2 MS with supplements of combinations of three plant hormones,ie. NAA,6-BA and 2,4-D,at different concentrations to screen the optimum hormone combinations for tissue culture. An orthogonal experimental design was arranged for the 3 plant hormones at 5 levels of concentration,and 25 optimal treatments were selected with 3 replicates each treatment for the experiment. The 1/2 MS with the combinations of the plant hormones was added with 50 g·L-1 sucrose and 1. 0 g·L-1 Hyponex in each petri dish to induce calli from the explants. The results showed that in the combinations of NAA and 6-BA the callus inducing rate was the highest,upto 97. 8%,in the medium supplemented with 2 mg·L-1 NAA and 0. 5 mg·L-16-BA,and that in the combinations of NAA and 2,4-D the callus inducing was the highest in the medium supplemented with 1. 5 mg·L-1 NAA and 1. 0 mg·L-12,4-D. No calli were induced in the medium supplemented only with NAA.
Young shoots of the stem of Bitter Leaf（ Vernonia amygdalina Del） were used as explants and cultured in the 1/2 MS with supplements of combinations of three plant hormones,ie. NAA,6-BA and 2,4-D,at different concentrations to screen the optimum hormone combinations for tissue culture. An orthogonal experimental design was arranged for the 3 plant hormones at 5 levels of concentration,and 25 optimal treatments were selected with 3 replicates each treatment for the experiment. The 1/2 MS with the combinations of the plant hormones was added with 50 g·L-1 sucrose and 1. 0 g·L-1 Hyponex in each petri dish to induce calli from the explants. The results showed that in the combinations of NAA and 6-BA the callus inducing rate was the highest,upto 97. 8%,in the medium supplemented with 2 mg·L-1 NAA and 0. 5 mg·L-16-BA,and that in the combinations of NAA and 2,4-D the callus inducing was the highest in the medium supplemented with 1. 5 mg·L-1 NAA and 1. 0 mg·L-12,4-D. No calli were induced in the medium supplemented only with NAA.
2017, 8(4): 424-430.
doi: 10.15886/j.cnki.rdswxb.2017.04.09
Abstract:
Fruits and leaves of noni（ Morinda citrifolia Linn.） were collected in Wanning,Danzhou,Qionghai,Sanya,Lingao and Haikou,Hainan Province,from which 32 strains of endophytic fungi were isolated,cultured at 25 ℃ and then identified by using 26 S r DNA D1/D2 and ITS r DNA sequencing. The results showed that these 32 strains belonged to the phylum Basidiomycota and the phylum Ascomycota. Of the 32 strains 13 belonged to 3 genera,i. e. Aureobasidium,Rhodotorula and Cryptococcus,and 5 species,and 19 belonged to 7 genera,i. e. Colletotrichum,Diaporthe,Hypoxylon,Cladosporium,Fusarium,Phyllosticta and Gibberella,and 10 species. The secondary metabolites were extracted with ethyl acetate as solvent from 15 fermented solutions of noni endophytic fungi,and their antioxidant activity was evaluated with ABTS+ ·-free radical scavenging assay.The total polyphenols content（ TPC） and total flavonoid content（ TFC） of the secondary metabolites were determined by using Folin-reagent method and Al Cl3 colorimetric method. The antioxidant assay showed that ethyl acetate extract from 15 solutions of endophytic fungi was full of antioxidant activity,and that the antioxidant activity of M48 and J22 was significantly different. Noni endophytic fungi had abundant diversity and the potential to produce antioxidant substances which have important application value and broad prospect in healthcare and medical sector.
Fruits and leaves of noni（ Morinda citrifolia Linn.） were collected in Wanning,Danzhou,Qionghai,Sanya,Lingao and Haikou,Hainan Province,from which 32 strains of endophytic fungi were isolated,cultured at 25 ℃ and then identified by using 26 S r DNA D1/D2 and ITS r DNA sequencing. The results showed that these 32 strains belonged to the phylum Basidiomycota and the phylum Ascomycota. Of the 32 strains 13 belonged to 3 genera,i. e. Aureobasidium,Rhodotorula and Cryptococcus,and 5 species,and 19 belonged to 7 genera,i. e. Colletotrichum,Diaporthe,Hypoxylon,Cladosporium,Fusarium,Phyllosticta and Gibberella,and 10 species. The secondary metabolites were extracted with ethyl acetate as solvent from 15 fermented solutions of noni endophytic fungi,and their antioxidant activity was evaluated with ABTS+ ·-free radical scavenging assay.The total polyphenols content（ TPC） and total flavonoid content（ TFC） of the secondary metabolites were determined by using Folin-reagent method and Al Cl3 colorimetric method. The antioxidant assay showed that ethyl acetate extract from 15 solutions of endophytic fungi was full of antioxidant activity,and that the antioxidant activity of M48 and J22 was significantly different. Noni endophytic fungi had abundant diversity and the potential to produce antioxidant substances which have important application value and broad prospect in healthcare and medical sector.
2017, 8(4): 431-435,458.
doi: 10.15886/j.cnki.rdswxb.2017.04.010
Abstract:
To evaluate the biological value of fouling organism,sea squirt,in marine aquaculture,Styela plicata,a dominant sea squirt species in the South China Sea,was collected fresh to prepare polypeptides from their tunic by extraction,and the extracted polypeptides were used to evaluate their capacities to scavenge free radicals DPPH and O2- for analysis of the in-vitro antioxidative activity of the polypeptides of different molecular weights.Tunic polypeptides of four molecular weights were prepared by extraction and ultrafiltration,and their antioxidative activities were compared in scavenging of the free radicals DPPH and O2-.The results showed that the ＜ 3 KD polypeptides had the highest antioxidative activity,of which the free radical scavenging rates of the polypeptides at the concentration of 2. 5 g·L-1 were（ 42. 97 ±1. 05） % for DPPH and（ 33. 50 ±0. 28） % for O2-.The3-10 KD polypeptides had a very similar antioxidative activity to the 10-30 KD polypeptides,and their scavenging rates for the free radicals DPPH and O2- were between 22% and 24%. The ＞ 30 KD polypeptides had the lowest free radical scavenging rates: 18. 34% for DPPH and 17. 88% for O2-.These results indicated that the polypeptides of four molecular weights extracted from Styela plicata tunic manifested good antioxidative activity when their concentrations ranged from 0. 5 to 2. 5 g·L-1,which suggests a potential to use these polypeptides to further develop ingredients for cosmetics and anti-aging health products.
To evaluate the biological value of fouling organism,sea squirt,in marine aquaculture,Styela plicata,a dominant sea squirt species in the South China Sea,was collected fresh to prepare polypeptides from their tunic by extraction,and the extracted polypeptides were used to evaluate their capacities to scavenge free radicals DPPH and O2- for analysis of the in-vitro antioxidative activity of the polypeptides of different molecular weights.Tunic polypeptides of four molecular weights were prepared by extraction and ultrafiltration,and their antioxidative activities were compared in scavenging of the free radicals DPPH and O2-.The results showed that the ＜ 3 KD polypeptides had the highest antioxidative activity,of which the free radical scavenging rates of the polypeptides at the concentration of 2. 5 g·L-1 were（ 42. 97 ±1. 05） % for DPPH and（ 33. 50 ±0. 28） % for O2-.The3-10 KD polypeptides had a very similar antioxidative activity to the 10-30 KD polypeptides,and their scavenging rates for the free radicals DPPH and O2- were between 22% and 24%. The ＞ 30 KD polypeptides had the lowest free radical scavenging rates: 18. 34% for DPPH and 17. 88% for O2-.These results indicated that the polypeptides of four molecular weights extracted from Styela plicata tunic manifested good antioxidative activity when their concentrations ranged from 0. 5 to 2. 5 g·L-1,which suggests a potential to use these polypeptides to further develop ingredients for cosmetics and anti-aging health products.
2017, 8(4): 436-443.
doi: 10.15886/j.cnki.rdswxb.2017.04.011
Abstract:
In order to study the effects of slope and altitude on species diversity of tropical rain forest communities,two quadrats with 2 500 m2 each were set up in lowland rain forest,ravine rainforest and mountain rain forest on the northern and southern slopes,respectively,in Wuzhishan Mountain,totaling 12 quadrats. The dominant species composition and species diversity of tree plant communities on northern and southern slopes were compared. The results showed that on the northern slopes the dominant species were Diospyros hainanensis,Spondias lakonensis and Dysoxylum gotadhora in the lowland rainforest; Schefflera heptaphylla,Spondias lakonensis and Litsea variabilis in the ravine rainforest; and,Castanopsis tonkinensis,Syzygium araiocladum and Syzygium hancei in the mountain rainforest. On the southern slopes the dominant species were Schefflera heptaphylla,Liquidambar formosana and Eurya nitida in the lowland rainforest; Heritiera parvifolia,Diospyros hainanensis and Wrightia laevis in the ravine rainforest; and,Diospyros hainanensis,Dacrycarpus imbricatus var.patulus and Heritiera parvifolia in the mountain rainforest. The species richness,Shannon-Weiner index,Simpson index and Pielou index were higher in the lowland rainforest than in the ravine rainforest and the mountain rain forest on the northern slopes. The species diversity on the southern slope was lower in the lowland rainforest than in the other two plant communities. The species diversity was higher in the ravine rainforests and the mountain rainforests at a relatively high altitude than in the lowland rainforest at a low altitude. The species diversity in the lowland rainforest,the ravine rainforest and the mountain rainforest were lower on the southern than on the northern slopes. The species similarity index in the lowland rainforest and the ravine rainforest was the highest on the southern and northern slopes,while the species similarity was low between the mountain rainforest at a high altitude and the lowland rainforest or the ravine rainforest.
In order to study the effects of slope and altitude on species diversity of tropical rain forest communities,two quadrats with 2 500 m2 each were set up in lowland rain forest,ravine rainforest and mountain rain forest on the northern and southern slopes,respectively,in Wuzhishan Mountain,totaling 12 quadrats. The dominant species composition and species diversity of tree plant communities on northern and southern slopes were compared. The results showed that on the northern slopes the dominant species were Diospyros hainanensis,Spondias lakonensis and Dysoxylum gotadhora in the lowland rainforest; Schefflera heptaphylla,Spondias lakonensis and Litsea variabilis in the ravine rainforest; and,Castanopsis tonkinensis,Syzygium araiocladum and Syzygium hancei in the mountain rainforest. On the southern slopes the dominant species were Schefflera heptaphylla,Liquidambar formosana and Eurya nitida in the lowland rainforest; Heritiera parvifolia,Diospyros hainanensis and Wrightia laevis in the ravine rainforest; and,Diospyros hainanensis,Dacrycarpus imbricatus var.patulus and Heritiera parvifolia in the mountain rainforest. The species richness,Shannon-Weiner index,Simpson index and Pielou index were higher in the lowland rainforest than in the ravine rainforest and the mountain rain forest on the northern slopes. The species diversity on the southern slope was lower in the lowland rainforest than in the other two plant communities. The species diversity was higher in the ravine rainforests and the mountain rainforests at a relatively high altitude than in the lowland rainforest at a low altitude. The species diversity in the lowland rainforest,the ravine rainforest and the mountain rainforest were lower on the southern than on the northern slopes. The species similarity index in the lowland rainforest and the ravine rainforest was the highest on the southern and northern slopes,while the species similarity was low between the mountain rainforest at a high altitude and the lowland rainforest or the ravine rainforest.
2017, 8(4): 444-452.
doi: 10.15886/j.cnki.rdswxb.2017.04.012
Abstract:
Pinus kwangtungensis is a special species of conifers in China,mainly distributed from the north tropics to the north pan-tropics. As P. kwangtungensis was distributed in the southernmost area in China it is of a great scientific value and practical significance to analyze the coexistence mechanism of community species,the community structure and stability of P. kwangtungensis forest. Four sample plots or quadrats were established:three from the Yingge Mountains and one from the Jiaxi Mountains,with a total land area of 144 00 square meters,6 060 m each plot,to make a comparative study in dominant population niche and inter-specific associations. The results showed that the niche breadth of P. kwangtungensis population in the four plots was in the order of Plot 4（ 2. 101 4） ＞ Plot 1（ 1. 601 6） ＞ Plot 2（ 1. 444 1） ＞ Plot 3（ 1. 170 1）,indicating P. kwangtungensis in Plot 4 had the highest adaptation and competition but the lowest in Plot 3. The niche overlap of P. kwangtungensis and other dominant populations in the four plots was similar to the niche breadth in the order of Plot 4 ＞Plot 1 ＞ Plot 2 ＞ Plot 3. In Plot 4 the P. kwangtungensis population had the highest niche overlap with other dominant populations and hence competed and excluded most seriously with other dominant populations. The pairs of the species with high niche overlap in each plot contributed 85%,84%,71% and 84% to the total pairs of the species,and the species in the community had a very high niche overlap in their use of the resource and living space. The results showed that the P. kwangtungensis community had a high interspecific similarity in requirements of the species for habitat and resource in Hainan,and that the species in the community did not have a high niche differentiation and had a high competition in use of the resources,indicating that this community was still an instable and transitional community from the needle and broad-leaved mixed forest to the evergreen broad-leaved forest.
Pinus kwangtungensis is a special species of conifers in China,mainly distributed from the north tropics to the north pan-tropics. As P. kwangtungensis was distributed in the southernmost area in China it is of a great scientific value and practical significance to analyze the coexistence mechanism of community species,the community structure and stability of P. kwangtungensis forest. Four sample plots or quadrats were established:three from the Yingge Mountains and one from the Jiaxi Mountains,with a total land area of 144 00 square meters,6 060 m each plot,to make a comparative study in dominant population niche and inter-specific associations. The results showed that the niche breadth of P. kwangtungensis population in the four plots was in the order of Plot 4（ 2. 101 4） ＞ Plot 1（ 1. 601 6） ＞ Plot 2（ 1. 444 1） ＞ Plot 3（ 1. 170 1）,indicating P. kwangtungensis in Plot 4 had the highest adaptation and competition but the lowest in Plot 3. The niche overlap of P. kwangtungensis and other dominant populations in the four plots was similar to the niche breadth in the order of Plot 4 ＞Plot 1 ＞ Plot 2 ＞ Plot 3. In Plot 4 the P. kwangtungensis population had the highest niche overlap with other dominant populations and hence competed and excluded most seriously with other dominant populations. The pairs of the species with high niche overlap in each plot contributed 85%,84%,71% and 84% to the total pairs of the species,and the species in the community had a very high niche overlap in their use of the resource and living space. The results showed that the P. kwangtungensis community had a high interspecific similarity in requirements of the species for habitat and resource in Hainan,and that the species in the community did not have a high niche differentiation and had a high competition in use of the resources,indicating that this community was still an instable and transitional community from the needle and broad-leaved mixed forest to the evergreen broad-leaved forest.
2017, 8(4): 453-458.
doi: 10.15886/j.cnki.rdswxb.2017.04.013
Abstract:
The structure and dynamic properties of the starch xanthate/carbon black/natural rubber composites were analyzed by using scanning electronic microscopy（ SEM）,rubber process analyzer（ RPA） and dynamic mechanical analyzer（ DMA）. The results showed that the interface bonding force of the composites when loaded with starch xanthates was improved effectively between filler or rubber ingredients and rubber matrix. The DMA results showed that the composites increased slightly their glass transition temperature,wet skid resistance,and rolling resistance and decreased their heat build-up and relaxation activation energy. Under strain,the compounds with different parts of starch xanthates increased slightly their Payne effect and dielectric power factor（ tanδ） but had opposite results as frequency decreased,and the G’ of the compound was best when the compound was filled with 6 parts of the starch xanthates.
The structure and dynamic properties of the starch xanthate/carbon black/natural rubber composites were analyzed by using scanning electronic microscopy（ SEM）,rubber process analyzer（ RPA） and dynamic mechanical analyzer（ DMA）. The results showed that the interface bonding force of the composites when loaded with starch xanthates was improved effectively between filler or rubber ingredients and rubber matrix. The DMA results showed that the composites increased slightly their glass transition temperature,wet skid resistance,and rolling resistance and decreased their heat build-up and relaxation activation energy. Under strain,the compounds with different parts of starch xanthates increased slightly their Payne effect and dielectric power factor（ tanδ） but had opposite results as frequency decreased,and the G’ of the compound was best when the compound was filled with 6 parts of the starch xanthates.
2017, 8(4): 459-465.
doi: 10.15886/j.cnki.rdswxb.2017.04.014
Abstract:
The two adjacent parts of the tree of Aquilaria sinensis had been induced to produce agarwood due to insect infestation and chopping for two years,and the compounds of the argarwood induced were analyzed by using the GC-MS. The GC-MS analysis indicated that the chemical compositions of the agarwood by the two methods were similar,but also had some differences between them. The relative contents of sesquiterpenes and chromones of the agarwood induced by insects were higher than those of the agarwood by chopping. This result shows that the chemical composition of the agarwood is affected by both the genetic factors of the tree and the external factors. In the two agarwood samples tested the quality of the agarwood caused by insects is better than that of the agarwood by chopping.
The two adjacent parts of the tree of Aquilaria sinensis had been induced to produce agarwood due to insect infestation and chopping for two years,and the compounds of the argarwood induced were analyzed by using the GC-MS. The GC-MS analysis indicated that the chemical compositions of the agarwood by the two methods were similar,but also had some differences between them. The relative contents of sesquiterpenes and chromones of the agarwood induced by insects were higher than those of the agarwood by chopping. This result shows that the chemical composition of the agarwood is affected by both the genetic factors of the tree and the external factors. In the two agarwood samples tested the quality of the agarwood caused by insects is better than that of the agarwood by chopping.
2017, 8(4): 466-473.
doi: 10.15886/j.cnki.rdswxb.2017.04.015
Abstract:
Chemical constituents were isolated from Retiboletus kauffmanii by repeated column chromatography and preparative HPLC,and their chemical structures were identified by spectral data and references. At the same time their acetylcholinesterase inhibitory activity,α-glucosidase inhibitory activity and anti-oxidative ability were tested. The analysis showed that 19 compounds were isolated from R. kauffmanii and identified as: ergosterol（ 1）,β-sitosterol（ 2）,methyl p-hydroxybenzen epropanoate（ 3）,P-hydroxyacetophenone（ 4）,methyl phydroxybenzoate（ 5）,caffeic acid methyl ester（ 6）,p-hydroxybenzoic acid（ 7）,p-methylphenol（ 8）,Nacetyltyramine（ 9）,3,4-dihydroxy-acetophenone（ 10）,Bis（ 2-ethylhexyl） phthalate（ 11）,vanillic acid（ 12）,protocatechuic acid（ 13）,5,6-dihydroxybenzofuran-2,3-dicarboxylic acid dimethyl ester（ 14）,phydroxycinnamate methyl（ 15）,ergosterol 5α,8α-peroxide（ 16）,isomaltose（ 17）,2-hydroxy-4-methylbenzoate（ 18）,and p-methoxyphenylpropionic acid（ 19）. The compounds 1,3,4,6,7,10,and 13 had a certain activity in DPPH free radical scavenging. The compound 1 showed acetylcholinesterase inhibitory activity and the compounds 6,8,10,13 had a certain inhibitory activity against α-glucosidase. All these compounds were obtained from R. kauffmanii for the first time,among which some showed DPPH free radical scavenging activity and inhibitory activity against α-glucosidase and acetylcholinesterase.
Chemical constituents were isolated from Retiboletus kauffmanii by repeated column chromatography and preparative HPLC,and their chemical structures were identified by spectral data and references. At the same time their acetylcholinesterase inhibitory activity,α-glucosidase inhibitory activity and anti-oxidative ability were tested. The analysis showed that 19 compounds were isolated from R. kauffmanii and identified as: ergosterol（ 1）,β-sitosterol（ 2）,methyl p-hydroxybenzen epropanoate（ 3）,P-hydroxyacetophenone（ 4）,methyl phydroxybenzoate（ 5）,caffeic acid methyl ester（ 6）,p-hydroxybenzoic acid（ 7）,p-methylphenol（ 8）,Nacetyltyramine（ 9）,3,4-dihydroxy-acetophenone（ 10）,Bis（ 2-ethylhexyl） phthalate（ 11）,vanillic acid（ 12）,protocatechuic acid（ 13）,5,6-dihydroxybenzofuran-2,3-dicarboxylic acid dimethyl ester（ 14）,phydroxycinnamate methyl（ 15）,ergosterol 5α,8α-peroxide（ 16）,isomaltose（ 17）,2-hydroxy-4-methylbenzoate（ 18）,and p-methoxyphenylpropionic acid（ 19）. The compounds 1,3,4,6,7,10,and 13 had a certain activity in DPPH free radical scavenging. The compound 1 showed acetylcholinesterase inhibitory activity and the compounds 6,8,10,13 had a certain inhibitory activity against α-glucosidase. All these compounds were obtained from R. kauffmanii for the first time,among which some showed DPPH free radical scavenging activity and inhibitory activity against α-glucosidase and acetylcholinesterase.
2017, 8(4): 474-481.
doi: 10.15886/j.cnki.rdswxb.2017.04.016
Abstract:
Eighty five diseases which occur in Citrus production in China mainland were listed. Their distribution and the organs of Citrus plants by which the diseases mainly attack were also described. Of the listed diseases there were 61 infectious diseases and 24 non-infectious diseases. The infectious diseases were caused by 79 pathogens including fungi,viruses（ viroids）,bacteria（ pseudo bacteria）,phytoplasma,nematodes and parasitic higher plants. Citrus yellow vein clearing virus,Citrus chlorotic dwarf-associated virus,Citrus leaf blotch virus,Citrus bark cracking viroid,Citrus viroid V,and Citrus viroid V（ CVd-VI） are new diseases identified in China.
Eighty five diseases which occur in Citrus production in China mainland were listed. Their distribution and the organs of Citrus plants by which the diseases mainly attack were also described. Of the listed diseases there were 61 infectious diseases and 24 non-infectious diseases. The infectious diseases were caused by 79 pathogens including fungi,viruses（ viroids）,bacteria（ pseudo bacteria）,phytoplasma,nematodes and parasitic higher plants. Citrus yellow vein clearing virus,Citrus chlorotic dwarf-associated virus,Citrus leaf blotch virus,Citrus bark cracking viroid,Citrus viroid V,and Citrus viroid V（ CVd-VI） are new diseases identified in China.
2017, 8(4): 482-487,494.
doi: 10.15886/j.cnki.rdswxb.2017.04.017
Abstract:
Insect immunity is a defense response against attack of exogenouspathogens or other adverse stimulation. The insect immune system is comprised of humoral immunity and cellular immunity. Both of the immunities act co-operatively in response to attack of exogenous pathogens such as bacteria,nematodes,virus,parasitic wasp eggs,etc. These immunity responses can be e influenced obviously by sublethal exposure to insecticides.The effect of sub-lethal dosage of insecticides on insect immune response was reviewed to have a good understanding of sublethal effect of insecticides,and the synergistic effects of combined application of sublethal dose of insecticides and mycopathogenes on pest insects. This review may provide a reference for combined application of chemical insecticides and bio-insecticides in integrated pest management.
Insect immunity is a defense response against attack of exogenouspathogens or other adverse stimulation. The insect immune system is comprised of humoral immunity and cellular immunity. Both of the immunities act co-operatively in response to attack of exogenous pathogens such as bacteria,nematodes,virus,parasitic wasp eggs,etc. These immunity responses can be e influenced obviously by sublethal exposure to insecticides.The effect of sub-lethal dosage of insecticides on insect immune response was reviewed to have a good understanding of sublethal effect of insecticides,and the synergistic effects of combined application of sublethal dose of insecticides and mycopathogenes on pest insects. This review may provide a reference for combined application of chemical insecticides and bio-insecticides in integrated pest management.
2017, 8(4): 488-494.
doi: 10.15886/j.cnki.rdswxb.2017.04.018
Abstract:
Chemical constituents isolated from Phellinus spp. mainly included terpenes,steroids,flavonoids,phenols,oxole and polysaccharides,and these constituents possessed comprehensive biological activity such as anti-tumor,immune regulation,blood sugar-lowering,anti-inflammatory effect,hepatoprotective effect and antioxidation. The chemical constituents and biological activity of Phellinus spp. were reviewed to provide a reference for the development of high-value products and innovative use of Phellinus resources.
Chemical constituents isolated from Phellinus spp. mainly included terpenes,steroids,flavonoids,phenols,oxole and polysaccharides,and these constituents possessed comprehensive biological activity such as anti-tumor,immune regulation,blood sugar-lowering,anti-inflammatory effect,hepatoprotective effect and antioxidation. The chemical constituents and biological activity of Phellinus spp. were reviewed to provide a reference for the development of high-value products and innovative use of Phellinus resources.
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