2015 Vol. 6, No. 1
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2015, 6(1): 1-10.
doi: 10.15886/j.cnki.rdswxb.2015.01.001
Abstract
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Abstract:
Orange-spotted grouper（ Epinephelus coioides） was fed diets containing different levels of protein（ 48%,43%,38%） and lipid（ 12%,10%,8%） at different feeding regimes for 8 weeks. The grouper fed the diets containing different levels of protein or lipid in the afternoon showed no significant difference（ P ＞ 0. 05） in weight gain（ WG）,feed efficiency（ FE） condition factor,hepatosomatic index（ HSI） and viscerosomatic index（ VSI）. The grouper fed the high protein and low lipid（ HP-LL） diet in the afternoon had significantly lower protein ratio [（ 1. 39 ± 0. 23） %] than those fed the low protein and high lipid（ LP-HL） diet（（ 1. 81 ± 0.30） %）,and had significantly lower body lipid content than those fed the other diets; the grouper fed the high protein and medium lipid（ HP-ML） diet showed significantly higher body protein content [（ 170. 9 ± 1. 5） g·kg-1]and muscle protein content [（ 215. 9 ± 3. 9） g·kg-1]than those fed the other diets. The grouper fed the HP-LL diet contained evidently lower glutamate pyruvate transaminase（ GPT）,albumin and total protein than those fed the high protein and high lipid（ HP-HL） diet and the HP-ML diet but had significantly（ P ＜ 0. 05）higher liver glucose-6-phosphate dehydrogenase（ G-6-PD） activities than those fed the other diets. The grouper fed the LP-HL diet had significantly（ P ＜ 0. 05） higher liver isocitrate dehydrogenase（ IDH） activities than those fed the other diets. Number of hepatocytes did not significantly differ among the grouper fed the experimental diets. The grouper fed the LP-HL and HP-LL diets exhibited enlarged hepatocytes with apparent steatosis in hepatocyte,and their hepatocytes contained the most vacuoles among those fed the other diets. It is concluded that reducing dietary protein level（ 43% or 38%） or lipid level（ 10% or 8%） in the diet fed in the afternoon did not give any negative impact to the growth of the grouper when the grouper were fed the HP-HL diet in the morning.
Orange-spotted grouper（ Epinephelus coioides） was fed diets containing different levels of protein（ 48%,43%,38%） and lipid（ 12%,10%,8%） at different feeding regimes for 8 weeks. The grouper fed the diets containing different levels of protein or lipid in the afternoon showed no significant difference（ P ＞ 0. 05） in weight gain（ WG）,feed efficiency（ FE） condition factor,hepatosomatic index（ HSI） and viscerosomatic index（ VSI）. The grouper fed the high protein and low lipid（ HP-LL） diet in the afternoon had significantly lower protein ratio [（ 1. 39 ± 0. 23） %] than those fed the low protein and high lipid（ LP-HL） diet（（ 1. 81 ± 0.30） %）,and had significantly lower body lipid content than those fed the other diets; the grouper fed the high protein and medium lipid（ HP-ML） diet showed significantly higher body protein content [（ 170. 9 ± 1. 5） g·kg-1]and muscle protein content [（ 215. 9 ± 3. 9） g·kg-1]than those fed the other diets. The grouper fed the HP-LL diet contained evidently lower glutamate pyruvate transaminase（ GPT）,albumin and total protein than those fed the high protein and high lipid（ HP-HL） diet and the HP-ML diet but had significantly（ P ＜ 0. 05）higher liver glucose-6-phosphate dehydrogenase（ G-6-PD） activities than those fed the other diets. The grouper fed the LP-HL diet had significantly（ P ＜ 0. 05） higher liver isocitrate dehydrogenase（ IDH） activities than those fed the other diets. Number of hepatocytes did not significantly differ among the grouper fed the experimental diets. The grouper fed the LP-HL and HP-LL diets exhibited enlarged hepatocytes with apparent steatosis in hepatocyte,and their hepatocytes contained the most vacuoles among those fed the other diets. It is concluded that reducing dietary protein level（ 43% or 38%） or lipid level（ 10% or 8%） in the diet fed in the afternoon did not give any negative impact to the growth of the grouper when the grouper were fed the HP-HL diet in the morning.
2015, 6(1): 11-17.
doi: 10.15886/j.cnki.rdswxb.2015.01.002
Abstract:
Litopenaeus vannamei were infected separately or co-infected with Vibrio anguillarum and white spot syndrome virus（ WSSV） at different concentrations under three different temperature conditions（ 19 ± 1,25 ±1,31 ± 1 ℃）. The infected L. vannamei were sampled at the 0,6 12,24,48,72,96 hrs after infection to observe and record their infection rate and mortality and determine their WSSV load. The cumulative mortality and WSSV load of L. vannamei infected were found lower than 11. 1% and 1. 2 × 103 copies / g,respectively during the experiment at the temperature of（ 19 ± 1） ℃. At the temperature of（ 25 ± 1） ℃ the cumulative mortality of L. vannamei was significantly different between the single infection of WSSV and the co-infection of WSSV and V. anguillarum at 48 h-96 h（ P ＜ 0. 05）,and between the co-infection groups（ P ＜ 0. 05）,with the maximum mortality of the co-infection group at the concentration of 2. 3 × 106cfu·m L-1 being 77. 8%. At the temperature of（ 31 ± 1） ℃,the cumulative mortality of L. vannamei in each infection group began to increase at 48 h,and the virus replication and the cumulative mortality of L. vannamei was significantly higher in the co-infection group than in the WSSV infection group. Therefore,V. anguillarum and WSSV had a low pathogenicity at the lower temperature. As the temperature increased,the pathogenicity of Vibrio anguillarum and WSSV in coinfection increased with the temperature. That means temperature could significantly affect the pathogenicity of V. anguillarum and WSSV.
Litopenaeus vannamei were infected separately or co-infected with Vibrio anguillarum and white spot syndrome virus（ WSSV） at different concentrations under three different temperature conditions（ 19 ± 1,25 ±1,31 ± 1 ℃）. The infected L. vannamei were sampled at the 0,6 12,24,48,72,96 hrs after infection to observe and record their infection rate and mortality and determine their WSSV load. The cumulative mortality and WSSV load of L. vannamei infected were found lower than 11. 1% and 1. 2 × 103 copies / g,respectively during the experiment at the temperature of（ 19 ± 1） ℃. At the temperature of（ 25 ± 1） ℃ the cumulative mortality of L. vannamei was significantly different between the single infection of WSSV and the co-infection of WSSV and V. anguillarum at 48 h-96 h（ P ＜ 0. 05）,and between the co-infection groups（ P ＜ 0. 05）,with the maximum mortality of the co-infection group at the concentration of 2. 3 × 106cfu·m L-1 being 77. 8%. At the temperature of（ 31 ± 1） ℃,the cumulative mortality of L. vannamei in each infection group began to increase at 48 h,and the virus replication and the cumulative mortality of L. vannamei was significantly higher in the co-infection group than in the WSSV infection group. Therefore,V. anguillarum and WSSV had a low pathogenicity at the lower temperature. As the temperature increased,the pathogenicity of Vibrio anguillarum and WSSV in coinfection increased with the temperature. That means temperature could significantly affect the pathogenicity of V. anguillarum and WSSV.
2015, 6(1): 18-24.
doi: 10.15886/j.cnki.rdswxb.2015.01.003
Abstract:
A strain of lactic acid bacteria HN3 isolated from Litopenaeus vannamei digestive tract was used to conduct experiments to observe its antagonistic effect on two pathogenic vibrio species: Vibrio harveyi and Vibrio parahaemolyticus and its aquacultural effect on the growth of L. vannamei. The antagonism experiment showed that both the lactic acid bacteria HN3 and its extracellular fluid showed significantly different inhibitory effects against the growth of V. harveyi and V. parahaemolyticus. The aquaculture experiment showed that the daily gain rate（ DGR）,survival rate（ SR） and specific growth rate（ SGR） of the shrimps fed the diet containing probiotic HN3 were significantly higher than those of the control（ P ＜ 0. 05）. Similarly,significantly higher population density of the lactic acid bacteria and total bacteria were noted in the shrimp digestive tract and culture water compared to the control,but the number of Vibrio bacteria was reduced greatly（ P ＜ 0. 05）. The diet supplemented with 4 × 106—5 × 106cfu·g-1 probiotic HN3 was the best to farm the shrimps,and the probiotic HN3 promoted the growth and improved the survival rate of the shrimps,which indicates that HN3 is adapted to the digestive tract environment,inhibits the growth of V. harveyi and V. parahaemolyticus and plays an important role in improving the composition of flora in the farming environment.
A strain of lactic acid bacteria HN3 isolated from Litopenaeus vannamei digestive tract was used to conduct experiments to observe its antagonistic effect on two pathogenic vibrio species: Vibrio harveyi and Vibrio parahaemolyticus and its aquacultural effect on the growth of L. vannamei. The antagonism experiment showed that both the lactic acid bacteria HN3 and its extracellular fluid showed significantly different inhibitory effects against the growth of V. harveyi and V. parahaemolyticus. The aquaculture experiment showed that the daily gain rate（ DGR）,survival rate（ SR） and specific growth rate（ SGR） of the shrimps fed the diet containing probiotic HN3 were significantly higher than those of the control（ P ＜ 0. 05）. Similarly,significantly higher population density of the lactic acid bacteria and total bacteria were noted in the shrimp digestive tract and culture water compared to the control,but the number of Vibrio bacteria was reduced greatly（ P ＜ 0. 05）. The diet supplemented with 4 × 106—5 × 106cfu·g-1 probiotic HN3 was the best to farm the shrimps,and the probiotic HN3 promoted the growth and improved the survival rate of the shrimps,which indicates that HN3 is adapted to the digestive tract environment,inhibits the growth of V. harveyi and V. parahaemolyticus and plays an important role in improving the composition of flora in the farming environment.
2015, 6(1): 25-29.
doi: 10.15886/j.cnki.rdswxb.2015.01.004
Abstract:
Paphia undulata（ Born,1778） collected from Shen’ao Bay,Shenzhen,Guangdong,China were fed thrice in the polyethylene buckets of 5 L with algal diet at different rates and different time in December 2013 to observe their filtration rates and carrying capacity by using the method for experimental ecology. P. undulata were observed to increase their filtration rates with their body weight,but their filtration rates per body weight were reduced with an increase in the body size of P. undulata: FR’ = 0. 330 3W-0. 356 9（ R2= 0. 996 5）. P. undulata were fed with algae Isochrysis galbana and Platymonas subcordiformis separately to observe their filtration rates at 8 am,14 pm and 20 pm,and the filtration rates were found maximum at 8 am,followed by at 14 pm and 20 pm,and showed significant difference among these three feeding hours（ P ＜ 0. 05）. P. undulata were fed with the mixture of I. galbana and P. subcordiformis,and their filtration rates were increased with the cell density of the mixed feed in the buckets,but decreased when the cell density exceeded 3. 06 × 105cell·L-1.
Paphia undulata（ Born,1778） collected from Shen’ao Bay,Shenzhen,Guangdong,China were fed thrice in the polyethylene buckets of 5 L with algal diet at different rates and different time in December 2013 to observe their filtration rates and carrying capacity by using the method for experimental ecology. P. undulata were observed to increase their filtration rates with their body weight,but their filtration rates per body weight were reduced with an increase in the body size of P. undulata: FR’ = 0. 330 3W-0. 356 9（ R2= 0. 996 5）. P. undulata were fed with algae Isochrysis galbana and Platymonas subcordiformis separately to observe their filtration rates at 8 am,14 pm and 20 pm,and the filtration rates were found maximum at 8 am,followed by at 14 pm and 20 pm,and showed significant difference among these three feeding hours（ P ＜ 0. 05）. P. undulata were fed with the mixture of I. galbana and P. subcordiformis,and their filtration rates were increased with the cell density of the mixed feed in the buckets,but decreased when the cell density exceeded 3. 06 × 105cell·L-1.
2015, 6(1): 30-40.
doi: 10.15886/j.cnki.rdswxb.2015.01.005
Abstract:
The species,quantity and spatial distribution of plankton during the shrimp culture cycle were observed in plastic-film-lined shrimp ponds from April to July 2012 at Haikou,Hainan,China to explore the spatial and temporal differences in plankton distribution in the shrimp ponds. During the shrimp culture there were 46 species under 8 phylums of phytoplankton in the shrimp ponds,including 15 species under the phylum chlorophyta; 9 under diatoms or cyanophyta; 2 under cryptophyta,euglenophyta,or dinoflagellates; 3 under xanthophyta,4 under chrysophyta. The dominant species were mostly under chlorophyta and bacillariophyta at the early stage of shrimp cutlure but mostly under cyanobacteria and chlorophyta at the mid and late stages. Their numbers of individuals of the phytoplankton were increased spirally and to the maximum at the mid stage of the culture,ranging from 3. 01 ×107 to 1. 45 × 108 cell / L. There were 28 species under 4 types of zooplankton: 16 species under protozoa,8 under rotatoria,2 under copepods and 2 species of larvae under other types of zooplankton. The dominant species were mostly under protozoa,rotatoria and copepods at the early stage of culture but mostly under protozoa and rotaria at the late stage of culture. The density of zooplankton increased gradually over time at the range of 0. 49 1. 2 × 103cell·L-1~10. 4 1. 2 × 103 cell·L-1. Spatial distribution of plankton had no significant difference in vertical distribution（ P ＞ 0. 05） but had significant differences in horizontal distribution（ P ＜0. 05） with the total number of individuals of plankton being in the order of D（ central area of the pond） ＞ C（ near the central area） ＞ B（ near the marginal area） ＞ A（ marginal area） area. The indexes of both diversity and dominance concentration of plankton were lower in the shrimp ponds,ranging between 1. 69 ~1. 76 and 0. 36 ~0. 44 for phytoplankton,respectively and 1. 39 ~1. 46 and 0. 3 ~0. 3 for zooplankton,respectively. Spatial and temporal differences in plankton distributionindirectly reflected the change of water quality in the film-lined shrimp ponds.
The species,quantity and spatial distribution of plankton during the shrimp culture cycle were observed in plastic-film-lined shrimp ponds from April to July 2012 at Haikou,Hainan,China to explore the spatial and temporal differences in plankton distribution in the shrimp ponds. During the shrimp culture there were 46 species under 8 phylums of phytoplankton in the shrimp ponds,including 15 species under the phylum chlorophyta; 9 under diatoms or cyanophyta; 2 under cryptophyta,euglenophyta,or dinoflagellates; 3 under xanthophyta,4 under chrysophyta. The dominant species were mostly under chlorophyta and bacillariophyta at the early stage of shrimp cutlure but mostly under cyanobacteria and chlorophyta at the mid and late stages. Their numbers of individuals of the phytoplankton were increased spirally and to the maximum at the mid stage of the culture,ranging from 3. 01 ×107 to 1. 45 × 108 cell / L. There were 28 species under 4 types of zooplankton: 16 species under protozoa,8 under rotatoria,2 under copepods and 2 species of larvae under other types of zooplankton. The dominant species were mostly under protozoa,rotatoria and copepods at the early stage of culture but mostly under protozoa and rotaria at the late stage of culture. The density of zooplankton increased gradually over time at the range of 0. 49 1. 2 × 103cell·L-1~10. 4 1. 2 × 103 cell·L-1. Spatial distribution of plankton had no significant difference in vertical distribution（ P ＞ 0. 05） but had significant differences in horizontal distribution（ P ＜0. 05） with the total number of individuals of plankton being in the order of D（ central area of the pond） ＞ C（ near the central area） ＞ B（ near the marginal area） ＞ A（ marginal area） area. The indexes of both diversity and dominance concentration of plankton were lower in the shrimp ponds,ranging between 1. 69 ~1. 76 and 0. 36 ~0. 44 for phytoplankton,respectively and 1. 39 ~1. 46 and 0. 3 ~0. 3 for zooplankton,respectively. Spatial and temporal differences in plankton distributionindirectly reflected the change of water quality in the film-lined shrimp ponds.
2015, 6(1): 41-46.
doi: 10.15886/j.cnki.rdswxb.2015.01.006
Abstract:
Based on the prediction result of secreted proteome of Colletotrichum gloeosporioides infecting rubber tree（ Hevea brasiliensis）,one of the candidate genes was cloned by RT-PCR and named as Biotrophy- associated Secreted Protein 2 of C. gloeosporioides（ CgBASP2）. This gene was sequenced and found to encode 100 amino acids with a relative molecular weight of about 9. 85 1. 2 × 103. Bioinformatics analysis showed that the gene contains an 18 aa signal peptide at N terminal,but without any transmembrane domain. Alignment analysis showed that the amino acid sequence of the gene CgBASP2 from H. brasiliensis is 100%,90%,87%,87% and 67%similar to that of the CgBASP2 from Colletotrichum gloeosporioides Nara gc5,Colletotrichum orbiculare MAFF,Colletotrichum graminicola,Colletotrichum higginsiaum and Magnaporthe oryzae 70-15,respectively. The CgBASP2 gene knockout mutant strain ΔCgBASP2 was constructed by using homologous recombination to study its biological functions. This ΔCgBASP2 mutant strain inoculated onto the leaves of rubber tree was found to lose pathogenicity while the wild type strain had good pathogenicity. This result implied that the CgBASP2 gene might probably play an important role in the pathogenicity of C. gloeosporioides.
Based on the prediction result of secreted proteome of Colletotrichum gloeosporioides infecting rubber tree（ Hevea brasiliensis）,one of the candidate genes was cloned by RT-PCR and named as Biotrophy- associated Secreted Protein 2 of C. gloeosporioides（ CgBASP2）. This gene was sequenced and found to encode 100 amino acids with a relative molecular weight of about 9. 85 1. 2 × 103. Bioinformatics analysis showed that the gene contains an 18 aa signal peptide at N terminal,but without any transmembrane domain. Alignment analysis showed that the amino acid sequence of the gene CgBASP2 from H. brasiliensis is 100%,90%,87%,87% and 67%similar to that of the CgBASP2 from Colletotrichum gloeosporioides Nara gc5,Colletotrichum orbiculare MAFF,Colletotrichum graminicola,Colletotrichum higginsiaum and Magnaporthe oryzae 70-15,respectively. The CgBASP2 gene knockout mutant strain ΔCgBASP2 was constructed by using homologous recombination to study its biological functions. This ΔCgBASP2 mutant strain inoculated onto the leaves of rubber tree was found to lose pathogenicity while the wild type strain had good pathogenicity. This result implied that the CgBASP2 gene might probably play an important role in the pathogenicity of C. gloeosporioides.
2015, 6(1): 47-52.
doi: 10.15886/j.cnki.rdswxb.2015.01.007
Abstract:
A new antagonistic yeast strain（ LZ5） was isolated from a mango orchard in Hainan Province. Antagonistic activity of this yeast strain was evaluated against postharvest anthracnose of mango fruit caused by Colletotrichum gloeosporioides through in vitro and in vivo assays. In vivo inoculation assay revealed that 1 × 108cfu·m L-1 of the yeast strain had significant biocontrol activity against C. gloeosporioides. The lesion diameter of the anthracnose pathogenic fungi was 5. 80 mm in the control and 0. 33 mm in the test group after 4 days of inoculation at 25°C,and 26. 3 mm in the control and 17. 6 mm in the test group after 6 days at 25°C,respectively,and the disease incidence was 100% in the control and 20% in the test group after 4 days of inoculation. Moreover,it was observed that the yeast strain LZ5 grew rapidly on the wounds of mango fruit. The yeast cell population increased 62. 6-fold 24 h after inoculation and was then stabilized for the rest of the storage period. The yeast strain LZ5 was identified as Meyerozyma guilliermondii.
A new antagonistic yeast strain（ LZ5） was isolated from a mango orchard in Hainan Province. Antagonistic activity of this yeast strain was evaluated against postharvest anthracnose of mango fruit caused by Colletotrichum gloeosporioides through in vitro and in vivo assays. In vivo inoculation assay revealed that 1 × 108cfu·m L-1 of the yeast strain had significant biocontrol activity against C. gloeosporioides. The lesion diameter of the anthracnose pathogenic fungi was 5. 80 mm in the control and 0. 33 mm in the test group after 4 days of inoculation at 25°C,and 26. 3 mm in the control and 17. 6 mm in the test group after 6 days at 25°C,respectively,and the disease incidence was 100% in the control and 20% in the test group after 4 days of inoculation. Moreover,it was observed that the yeast strain LZ5 grew rapidly on the wounds of mango fruit. The yeast cell population increased 62. 6-fold 24 h after inoculation and was then stabilized for the rest of the storage period. The yeast strain LZ5 was identified as Meyerozyma guilliermondii.
2015, 6(1): 53-58,64.
doi: 10.15886/j.cnki.rdswxb.2015.01.008
Abstract:
Pseudomonas alcaligenes was cultured on various media to optimize fermentation conditions to produce arginine deiminase（ ADI）. The fermentation conditions for P. alcaligenes to produce ADI were found optimum when 10g·L-1 sucrose was used as the carbon source,6 g·L-1 peptone as the optimal nitrogen source,10 g·L-1 arginineas the inducer,inoculation amount was 4%,liquid volume was 30 m L per 100 m L,incubation temperature was 29 ℃,initial p H was 8. 5,shaker rotation speed was 150 r·min-1 and fermentation time was 24 h.Under these fermentation conditions the arginine deiminase produced from P. alcaligenes had the highest activities.
Pseudomonas alcaligenes was cultured on various media to optimize fermentation conditions to produce arginine deiminase（ ADI）. The fermentation conditions for P. alcaligenes to produce ADI were found optimum when 10g·L-1 sucrose was used as the carbon source,6 g·L-1 peptone as the optimal nitrogen source,10 g·L-1 arginineas the inducer,inoculation amount was 4%,liquid volume was 30 m L per 100 m L,incubation temperature was 29 ℃,initial p H was 8. 5,shaker rotation speed was 150 r·min-1 and fermentation time was 24 h.Under these fermentation conditions the arginine deiminase produced from P. alcaligenes had the highest activities.
2015, 6(1): 59-64.
doi: 10.15886/j.cnki.rdswxb.2015.01.009
Abstract:
Cassava bacterial blight（ CBB） is a destructive disease of cassava（ Manihot esculenta） and is caused by Xanthomonas axonopodis pv manihotis,Xam. This disease had invoked a serious damage to cassava industry in other countries. The pathogen of the CBB was isolated from the infected leaves collected from cassava varieties SC8 and SC5 in Qiongzhong County,Hainan,and then purified for morphological observation,pathogenecity assay and biochemical assay. This pathogen was also identified by using 16 S r DNA gene sequence analysis. The results showed that the isolated pathogen was Xanthomonas axonopodis.
Cassava bacterial blight（ CBB） is a destructive disease of cassava（ Manihot esculenta） and is caused by Xanthomonas axonopodis pv manihotis,Xam. This disease had invoked a serious damage to cassava industry in other countries. The pathogen of the CBB was isolated from the infected leaves collected from cassava varieties SC8 and SC5 in Qiongzhong County,Hainan,and then purified for morphological observation,pathogenecity assay and biochemical assay. This pathogen was also identified by using 16 S r DNA gene sequence analysis. The results showed that the isolated pathogen was Xanthomonas axonopodis.
2015, 6(1): 65-68.
doi: 10.15886/j.cnki.rdswxb.2015.01.010
Abstract:
The sucrose accumulation characteristics of sugarcane planted at different altitudes in different months were analyzed. Sugarcane cultivar Mintang 69 /421 was planted in the field at the altitudes of 400 m,600 m,800 m,1 000 m,1 200 m,1 400 m and 1 600 m,respectively,and the Brix or sugarcane sucrose content was measured in different months. The altitude was found to give different influences to the sucrose content of the sugarcane at different accumulation stages. The sucrose content of the sugarcane was affected greatly at the altitude between 400 m and 1 000 m at the early accumulation stage,and it decreased as the altitude increases. But the sugarcane sucrose content did not change much at the altitude between 1 000 m and 1 600 m. The altitude had slight influence on the sucrose accumulation at the middle and late accumulation stages. As the altitude increased the sugarcane sucrose accumulation generally tended to decrease but not considerably,and the sucrose content changed much at different altitudes. Numerous other environmental factors beside altitude gave influence to sugarcane sucrose accumulation.
The sucrose accumulation characteristics of sugarcane planted at different altitudes in different months were analyzed. Sugarcane cultivar Mintang 69 /421 was planted in the field at the altitudes of 400 m,600 m,800 m,1 000 m,1 200 m,1 400 m and 1 600 m,respectively,and the Brix or sugarcane sucrose content was measured in different months. The altitude was found to give different influences to the sucrose content of the sugarcane at different accumulation stages. The sucrose content of the sugarcane was affected greatly at the altitude between 400 m and 1 000 m at the early accumulation stage,and it decreased as the altitude increases. But the sugarcane sucrose content did not change much at the altitude between 1 000 m and 1 600 m. The altitude had slight influence on the sucrose accumulation at the middle and late accumulation stages. As the altitude increased the sugarcane sucrose accumulation generally tended to decrease but not considerably,and the sucrose content changed much at different altitudes. Numerous other environmental factors beside altitude gave influence to sugarcane sucrose accumulation.
2015, 6(1): 69-77.
doi: 10.15886/j.cnki.rdswxb.2015.01.011
Abstract:
A field experiment was conducted to decompose the leaf litters of Maclurodendron oligophlebium,a common leaf litter dominant species,and Hydnocarpus hainanensis,a community dominant species,and the mixed leaf litters of the aforesaid species and other tree species at 2 succession stages in the primary tropical evergreen monsoon rains elfin forest and the foothill shrubs regenerated naturally due to human disturbance in Hainan Tongguling National Natural Reserve to observe the relationship between the leaf litter decomposition and the forest succession,and the nutrient release patterns. One year decomposition of the leaf litters showed the leaf litter decomposition rate was significantly higher in the monsoon elfin forest than in the foothill shrubs. The N release in the leaf litters followed the pattern of "enrichment-release",and the other elements such as C,K,Ca,P and Mg in the leaf litters were all directly released. In the monsoon elfin forest,the decomposition coefficient k had significantly positive correlation with the initial N mass fraction（ P ＜ 0. 05）,and highly significantly negative correlation with the initial C/N ratio（ P ＜ 0. 01）. In the foothill shrubs,the decomposition coefficient k was significantly negatively correlated with the initial C mass fraction and C/N value（ P＜ 0.05）.
A field experiment was conducted to decompose the leaf litters of Maclurodendron oligophlebium,a common leaf litter dominant species,and Hydnocarpus hainanensis,a community dominant species,and the mixed leaf litters of the aforesaid species and other tree species at 2 succession stages in the primary tropical evergreen monsoon rains elfin forest and the foothill shrubs regenerated naturally due to human disturbance in Hainan Tongguling National Natural Reserve to observe the relationship between the leaf litter decomposition and the forest succession,and the nutrient release patterns. One year decomposition of the leaf litters showed the leaf litter decomposition rate was significantly higher in the monsoon elfin forest than in the foothill shrubs. The N release in the leaf litters followed the pattern of "enrichment-release",and the other elements such as C,K,Ca,P and Mg in the leaf litters were all directly released. In the monsoon elfin forest,the decomposition coefficient k had significantly positive correlation with the initial N mass fraction（ P ＜ 0. 05）,and highly significantly negative correlation with the initial C/N ratio（ P ＜ 0. 01）. In the foothill shrubs,the decomposition coefficient k was significantly negatively correlated with the initial C mass fraction and C/N value（ P＜ 0.05）.
2015, 6(1): 78-86.
doi: 10.15886/j.cnki.rdswxb.2015.01.012
Abstract:
Landscape design of Golf has become a specific design project with the popularization of golf sport. As an important part of Golf landscape,plants have been involved in an overall course design,making more perfect the golf landscape design and reflecting the unique content and style of the golf course. An investigation and analysis was made of 3 tropical plain golf courses in Haikou,Hainan,China in terms of landscape space layout,plant design,landscape elements and artificial plant community. The data of these 3 golf courses from field investigation and the literature consulted were used for quantitative and qualitative analysis. The space layout and plant landscape were found slightly simple since the separation feature and linear planting were the most important landscape mode. The landscape elements were better arranged with unique style and charm due to use of tropical plants and colorful plants. Common landscape plants and alien invasive plants dominated the artificial plant community but with few native plants,indicating an obvious artificial landscape in the golf courses.
Landscape design of Golf has become a specific design project with the popularization of golf sport. As an important part of Golf landscape,plants have been involved in an overall course design,making more perfect the golf landscape design and reflecting the unique content and style of the golf course. An investigation and analysis was made of 3 tropical plain golf courses in Haikou,Hainan,China in terms of landscape space layout,plant design,landscape elements and artificial plant community. The data of these 3 golf courses from field investigation and the literature consulted were used for quantitative and qualitative analysis. The space layout and plant landscape were found slightly simple since the separation feature and linear planting were the most important landscape mode. The landscape elements were better arranged with unique style and charm due to use of tropical plants and colorful plants. Common landscape plants and alien invasive plants dominated the artificial plant community but with few native plants,indicating an obvious artificial landscape in the golf courses.
2015, 6(1): 87-90.
doi: 10.15886/j.cnki.rdswxb.2015.01.013
Abstract:
Total RNA of leaves of Areca nut（ Areca catechu L） were extracted by using universal plant total RNA extraction kit and the guanidine isothiocyanate-phenol method to develop an optimum total RNA extraction protocol for Areca leaves for high-throughput sequencing. A better quality of Areca leaf total RNA was extracted by the guanidine isothiocyanate- phenol than the universal plant total RNA extraction kit. Furthermore,two methods,heat treatment and phenol-chloroform extraction,were tried to inactivate DNAase I after total RNA was digested by this enzyme. It was found that the total leaf RNA was degraded when heat treated at 70 ℃ for 10 min,whereas high-purity and high concentration of total leaf RNA was obtained through phenol-chloroform extraction. The quality of total RNA with OD260/ OD280= 1. 98,OD260/ OD230= 2. 31 and concentration more than 979 mg·L-1,met the standard requirements for high-throughput RNA sequencing.
Total RNA of leaves of Areca nut（ Areca catechu L） were extracted by using universal plant total RNA extraction kit and the guanidine isothiocyanate-phenol method to develop an optimum total RNA extraction protocol for Areca leaves for high-throughput sequencing. A better quality of Areca leaf total RNA was extracted by the guanidine isothiocyanate- phenol than the universal plant total RNA extraction kit. Furthermore,two methods,heat treatment and phenol-chloroform extraction,were tried to inactivate DNAase I after total RNA was digested by this enzyme. It was found that the total leaf RNA was degraded when heat treated at 70 ℃ for 10 min,whereas high-purity and high concentration of total leaf RNA was obtained through phenol-chloroform extraction. The quality of total RNA with OD260/ OD280= 1. 98,OD260/ OD230= 2. 31 and concentration more than 979 mg·L-1,met the standard requirements for high-throughput RNA sequencing.
2015, 6(1): 91-97.
doi: 10.15886/j.cnki.rdswxb.2015.01.014
Abstract:
Hainan Island is one of the largest areas with tropical rain forests in China. Forest biodiversity is of great significance to maintain the global ecological system stability and plays an important role in promoting the forest eco tourism. The forest biodiversity in Hainan Island is essential for the sustainable development of international tourism in Hainan Island. We analyze the relationship between the forest biodiversity and the ecological tourism development and describe the current status of forest biodiversity and the existing problems in Hainan Island. Some countermeasures are then put forward to conserve the forest biodiversity in order to provide references for the sustainable development of ecological environment and forest ecotourism in Hainan Island.
Hainan Island is one of the largest areas with tropical rain forests in China. Forest biodiversity is of great significance to maintain the global ecological system stability and plays an important role in promoting the forest eco tourism. The forest biodiversity in Hainan Island is essential for the sustainable development of international tourism in Hainan Island. We analyze the relationship between the forest biodiversity and the ecological tourism development and describe the current status of forest biodiversity and the existing problems in Hainan Island. Some countermeasures are then put forward to conserve the forest biodiversity in order to provide references for the sustainable development of ecological environment and forest ecotourism in Hainan Island.
2015, 6(1): 98-104.
doi: 10.15886/j.cnki.rdswxb.2015.01.015
Abstract:
The bio-safety of genetically modified crops has attracted a global attention. Many countries and international organizations have formulated relevant laws and regulations for safety management of the genetically modified crops. For the bio-safety of the genetically modified crops these crops need bio-safety evaluation,and detection and evaluation technologies for the transgenic crops are key to tell whether the genetically modified crops are biologically safe. The main detection technologies for safety evaluation of the genetically modified crops were reviewed,especially the untargeted "omics"technologies such as transcriptomics,proteomics and metabolomics and their use in bio-safety evaluation of unintended effects of the genetically modified crops.
The bio-safety of genetically modified crops has attracted a global attention. Many countries and international organizations have formulated relevant laws and regulations for safety management of the genetically modified crops. For the bio-safety of the genetically modified crops these crops need bio-safety evaluation,and detection and evaluation technologies for the transgenic crops are key to tell whether the genetically modified crops are biologically safe. The main detection technologies for safety evaluation of the genetically modified crops were reviewed,especially the untargeted "omics"technologies such as transcriptomics,proteomics and metabolomics and their use in bio-safety evaluation of unintended effects of the genetically modified crops.
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