This paper has analyzed allelopathic effects ofNerium indicum on Oncomelania hupensis through triterpene sapogenins, a potential molluscicide. The snails were treated under six various concentrations （0, 20, 40, 60, ...This paper has analyzed allelopathic effects ofNerium indicum on Oncomelania hupensis through triterpene sapogenins, a potential molluscicide. The snails were treated under six various concentrations （0, 20, 40, 60, 80, 100 mg/L） of triterpene sapogenins and five periods （1, 2, 3, 4, 5 days）. The mortality of snails was positively correlated with the concentration of triterpene sapogenins and exposure time. The results ofprobit analysis showed that the LD50 （Lethal Dose, 50%） oftriterpenoid saponins from N. indicum by immersion for 2, 3, 4, 5 days were 78.31, 30.26, 20.50, 14.19 mg/L, respectively. And the corresponding 95% confidence intervals were 63.60-108.19, 9.49-44.42, 2.86-30.90, 0.23-22.79 mg/L, respectively. The observations of both scanning electron microscope and transmission electron microscope proved that 40 mg/L triterpene sapogenins could cause apparent damage to the structure of soft tissue, liver and intestine of O. hupensis. The esterase （EST） isozyme electrophoresis in liver of O. hupensis treated by 40 mg/L of the concentrations lixivium of the triterpene sapogenins from N. indicum was analyzed for 24, 48, 72, 96, 120 h, respectively. The activity of enzyme was higher than control water group after been treated up to 24-48 h, and then lowered and disappeared after 72 h. It was implicated that the extracted triterpene sapogenin from N. indicum were promising for controlling the snail, which were also providing the foundation for constructing plant community of oleander to control O. hupensis.展开更多
Currently, China is home to more than four million hectares of oil plants nationwide, and 154 kinds of energy trees could produce seeds containing more than 40 percent of oil, with total production of the seeds totali...Currently, China is home to more than four million hectares of oil plants nationwide, and 154 kinds of energy trees could produce seeds containing more than 40 percent of oil, with total production of the seeds totaling five million tons. Another 57 million hectares of waste land are available and suitable for planting trees for the production of forest-based bioenergy, of which there is 630,000 hm2 beach land in the middle and lower reaches of Yangtze River where is suited for poplar growing. In order to approach the potential of poplar biomass production, the test was conducted in the paper. The result indicated that in the poplar forest ecosystem the herbaceous biomass production was 15.554 t/hm2. While biomass production for trees was 43.164 t/hm2, totally in the poplar plantation ecosystem biomass production reached 58.718 t/hm2. As well, poplars growing added incomes for local farmers.展开更多
基金Acknowledgments The authors would like to thank the National Natural Science Foundation of China （grant No. 30471506, 30570322, 39670654, 30671818） and the Science and Technology Foundation of Forest （No. 2006BAD03AI 5） for providing funds to the research.
文摘This paper has analyzed allelopathic effects ofNerium indicum on Oncomelania hupensis through triterpene sapogenins, a potential molluscicide. The snails were treated under six various concentrations （0, 20, 40, 60, 80, 100 mg/L） of triterpene sapogenins and five periods （1, 2, 3, 4, 5 days）. The mortality of snails was positively correlated with the concentration of triterpene sapogenins and exposure time. The results ofprobit analysis showed that the LD50 （Lethal Dose, 50%） oftriterpenoid saponins from N. indicum by immersion for 2, 3, 4, 5 days were 78.31, 30.26, 20.50, 14.19 mg/L, respectively. And the corresponding 95% confidence intervals were 63.60-108.19, 9.49-44.42, 2.86-30.90, 0.23-22.79 mg/L, respectively. The observations of both scanning electron microscope and transmission electron microscope proved that 40 mg/L triterpene sapogenins could cause apparent damage to the structure of soft tissue, liver and intestine of O. hupensis. The esterase （EST） isozyme electrophoresis in liver of O. hupensis treated by 40 mg/L of the concentrations lixivium of the triterpene sapogenins from N. indicum was analyzed for 24, 48, 72, 96, 120 h, respectively. The activity of enzyme was higher than control water group after been treated up to 24-48 h, and then lowered and disappeared after 72 h. It was implicated that the extracted triterpene sapogenin from N. indicum were promising for controlling the snail, which were also providing the foundation for constructing plant community of oleander to control O. hupensis.
文摘Currently, China is home to more than four million hectares of oil plants nationwide, and 154 kinds of energy trees could produce seeds containing more than 40 percent of oil, with total production of the seeds totaling five million tons. Another 57 million hectares of waste land are available and suitable for planting trees for the production of forest-based bioenergy, of which there is 630,000 hm2 beach land in the middle and lower reaches of Yangtze River where is suited for poplar growing. In order to approach the potential of poplar biomass production, the test was conducted in the paper. The result indicated that in the poplar forest ecosystem the herbaceous biomass production was 15.554 t/hm2. While biomass production for trees was 43.164 t/hm2, totally in the poplar plantation ecosystem biomass production reached 58.718 t/hm2. As well, poplars growing added incomes for local farmers.
