The potato tuberworm Phthorimaea operculella Zeller, is one of the most important potato pests worldwide including China. Several reports indicate that P. operculella could be controlled biologically by the use of ben...The potato tuberworm Phthorimaea operculella Zeller, is one of the most important potato pests worldwide including China. Several reports indicate that P. operculella could be controlled biologically by the use of beneficial fungus such as Beauveria bassiana(Bals.-Criv) Vuill. However, limited information is available under growing conditions in China. Thus, this study evaluated the sub-lethal effects of B. bassiana on the offspring of P. operculella by the age-stage, two-sex life table. First instar larva of P. operculella were treated with 1×107 conidia m L–1 of the fungus, and several biological parameters were evaluated. The fecundity, duration of the egg stage, all larval stages, pre-adult stage, and total pre-oviposition period, were significantly shorter than the control treatment. Offspring of treated parents, presented a net reproductive rate and mean generation time of 17.43 per day and 24.98 days, respectively, compared to 65.79 per day and 26.51 days for the untreated ones. This study provides basic information to help understanding the potential long-term effects of entomopathogenic fungi on P. operculella.展开更多
Lethal and sub-lethal effects of transgenic rice containing cry1Ac and CpTI genes on the pink stem borer, Sesamia inferens, were studied to collect information for ecological risk assessment on insect-resistance of tr...Lethal and sub-lethal effects of transgenic rice containing cry1Ac and CpTI genes on the pink stem borer, Sesamia inferens, were studied to collect information for ecological risk assessment on insect-resistance of transgenic rice. In vitro insect-feeding bioassays were conducted to evaluate the lethal and sub-lethal effects of transgenic rice lines （II YouKF6 and KF6） containing cry1Ac＋CpTI genes on S. inferens at four different growth stages, viz., seedling, tillering and elongation, booting, and milk and maturing. Transgenic rice at seedling stage showed significantly high lethal effect on S. inferens with the shortest lethal duration for 50 and 100% individuals and the highest corrected mortalities after feeding on transgenic lines at this stage for 3 and 6 d. Followed by tillering and elongation stage, 50 and 100% S. inferens were dead after feeding on transgenic lines at this stage for 4 and 10 d, respectively. Moreover, corrected mortalities for 6 d feeding on transgenic lines at this stage were significantly higher than that at booting, and milk and maturing stages. Lethal effect of KF6 on S. inferens decreased significantly at booting stage. Lethal duration for 50% S. inferens significantly extended and its corrected mortalities for 6 d feeding also declined remarkably. However, lethal effect of II YouKF6 on S. inferens did not decrease significantly at this stage. Transgenic rice at booting, and milk and maturing stages did not show significant lethal effect to S. inferens and it showed the longest lethal duration for 50% individuals and the lowest corrected mortalities for 3 and 6 d feeding. A few larvae of S. inferens could survive, pupate and emerge on these two transgenic lines at booting, and milk and maturing stages. Sub-lethal effect of two transgenic lines on S. inferens also differed significantly between different developmental stages. Continuously feeding on transgenic rice lines at seedling, and tillering and elongation stages delayed the development of larvae and pupae and decreased pupation rate, but no effect was observed on eclosion rate. Larval development was significantly inhibited after feeding on transgenic rice at booting stage, but no obvious effect was observed in pupal stage, pupation and eclosion rate. There were no significant differences for larval and pupal development, pupation, and eclosion rates between feeding on transgenic and control rice lines at milk and maturing stage. Larval and pupal weights significantly declined, but no influence was observed on fecundity when S. inferens infested on transgenic rice at any stage. These showed that there were significant differences in lethal and sub-lethal effects of transgenic rice on S. inferens among developmental stages, and the effects gradually decreased with the increase of growth stages of rice plant.展开更多
The impact of sub-lethal concentrations(0.05,0.5,5 μmol L 1) of the heavy metals copper(Cu),chromium(Cr),zinc(Zn),cadmium(Cd) and lead(Pb) on the growth and photosynthesis of Chlorella vulgaris was studied during 96 ...The impact of sub-lethal concentrations(0.05,0.5,5 μmol L 1) of the heavy metals copper(Cu),chromium(Cr),zinc(Zn),cadmium(Cd) and lead(Pb) on the growth and photosynthesis of Chlorella vulgaris was studied during 96 h exposure experiments.The results showed that the effects of these five metals on the growth of Chlorella vulgaris were dependent on both concentration and exposure time.It was found that 5 μmol L 1 treatments of Cu,Cr,Zn,Cd and Pb significantly inhibited the growth of Chlorella vulgaris,and the effect became weaker with an increase in exposure duration.Different effects on chlorophyll fluorescence were found for different metals,with Cu and Cr having an inhibiting effect and Zn and Cd having a promoting effect.The effects of heavy metals upon the growth and photosynthesis of Chlorella vulgaris were independent of each other and not causally related.展开更多
The lethal dose LD<sub>50</sub> represents the most important experimental value for acute toxicity. The simple logarithmic calculation of -log<sub>10</sub> LD<sub>50</sub> = value ...The lethal dose LD<sub>50</sub> represents the most important experimental value for acute toxicity. The simple logarithmic calculation of -log<sub>10</sub> LD<sub>50</sub> = value leads to the possible poison power pLD. As with the pH or pK value, respectively, for acid or the scale of earthquake intensities the logarithm helps making large differences of orders of magnitude easier to understand since they are more comparable. The higher the pLD value, the higher is the power of poison. An increase of the pLD value by 1 stands for a tenfold increase in toxicity. The lethal acute dose for water, one of the most important and at the same time non-toxic substances of all, is about one tenth of the body weight. This leads to a possible pLD value for water of 1, an ideal starting value for a logarithmic poison scale.展开更多
基金supported by the External Cooperation Program of Yunnan Province,China(2014IB002)
文摘The potato tuberworm Phthorimaea operculella Zeller, is one of the most important potato pests worldwide including China. Several reports indicate that P. operculella could be controlled biologically by the use of beneficial fungus such as Beauveria bassiana(Bals.-Criv) Vuill. However, limited information is available under growing conditions in China. Thus, this study evaluated the sub-lethal effects of B. bassiana on the offspring of P. operculella by the age-stage, two-sex life table. First instar larva of P. operculella were treated with 1×107 conidia m L–1 of the fungus, and several biological parameters were evaluated. The fecundity, duration of the egg stage, all larval stages, pre-adult stage, and total pre-oviposition period, were significantly shorter than the control treatment. Offspring of treated parents, presented a net reproductive rate and mean generation time of 17.43 per day and 24.98 days, respectively, compared to 65.79 per day and 26.51 days for the untreated ones. This study provides basic information to help understanding the potential long-term effects of entomopathogenic fungi on P. operculella.
基金funded by the National 973 Program of China (2007CB109204)the Major Projects of National Genetically Modified Organisms Breeding of China (2009ZX08011-007B, 2008ZX08011-001A)
文摘Lethal and sub-lethal effects of transgenic rice containing cry1Ac and CpTI genes on the pink stem borer, Sesamia inferens, were studied to collect information for ecological risk assessment on insect-resistance of transgenic rice. In vitro insect-feeding bioassays were conducted to evaluate the lethal and sub-lethal effects of transgenic rice lines （II YouKF6 and KF6） containing cry1Ac＋CpTI genes on S. inferens at four different growth stages, viz., seedling, tillering and elongation, booting, and milk and maturing. Transgenic rice at seedling stage showed significantly high lethal effect on S. inferens with the shortest lethal duration for 50 and 100% individuals and the highest corrected mortalities after feeding on transgenic lines at this stage for 3 and 6 d. Followed by tillering and elongation stage, 50 and 100% S. inferens were dead after feeding on transgenic lines at this stage for 4 and 10 d, respectively. Moreover, corrected mortalities for 6 d feeding on transgenic lines at this stage were significantly higher than that at booting, and milk and maturing stages. Lethal effect of KF6 on S. inferens decreased significantly at booting stage. Lethal duration for 50% S. inferens significantly extended and its corrected mortalities for 6 d feeding also declined remarkably. However, lethal effect of II YouKF6 on S. inferens did not decrease significantly at this stage. Transgenic rice at booting, and milk and maturing stages did not show significant lethal effect to S. inferens and it showed the longest lethal duration for 50% individuals and the lowest corrected mortalities for 3 and 6 d feeding. A few larvae of S. inferens could survive, pupate and emerge on these two transgenic lines at booting, and milk and maturing stages. Sub-lethal effect of two transgenic lines on S. inferens also differed significantly between different developmental stages. Continuously feeding on transgenic rice lines at seedling, and tillering and elongation stages delayed the development of larvae and pupae and decreased pupation rate, but no effect was observed on eclosion rate. Larval development was significantly inhibited after feeding on transgenic rice at booting stage, but no obvious effect was observed in pupal stage, pupation and eclosion rate. There were no significant differences for larval and pupal development, pupation, and eclosion rates between feeding on transgenic and control rice lines at milk and maturing stage. Larval and pupal weights significantly declined, but no influence was observed on fecundity when S. inferens infested on transgenic rice at any stage. These showed that there were significant differences in lethal and sub-lethal effects of transgenic rice on S. inferens among developmental stages, and the effects gradually decreased with the increase of growth stages of rice plant.
基金supported by the Key Program of National Natural Science Foundation of China (41030529)the National Natural Science Founds for Distinguished Young Scholars (40725004)+2 种基金the National Project for Water Pollution Control (2008ZX07103-005-01)the Specific Scientific Research Funds for Environment Protection Commonweal Section of China(20100932)Doctoral Fund of Ministry of Education of China(20100001110035)
文摘The impact of sub-lethal concentrations(0.05,0.5,5 μmol L 1) of the heavy metals copper(Cu),chromium(Cr),zinc(Zn),cadmium(Cd) and lead(Pb) on the growth and photosynthesis of Chlorella vulgaris was studied during 96 h exposure experiments.The results showed that the effects of these five metals on the growth of Chlorella vulgaris were dependent on both concentration and exposure time.It was found that 5 μmol L 1 treatments of Cu,Cr,Zn,Cd and Pb significantly inhibited the growth of Chlorella vulgaris,and the effect became weaker with an increase in exposure duration.Different effects on chlorophyll fluorescence were found for different metals,with Cu and Cr having an inhibiting effect and Zn and Cd having a promoting effect.The effects of heavy metals upon the growth and photosynthesis of Chlorella vulgaris were independent of each other and not causally related.
文摘The lethal dose LD<sub>50</sub> represents the most important experimental value for acute toxicity. The simple logarithmic calculation of -log<sub>10</sub> LD<sub>50</sub> = value leads to the possible poison power pLD. As with the pH or pK value, respectively, for acid or the scale of earthquake intensities the logarithm helps making large differences of orders of magnitude easier to understand since they are more comparable. The higher the pLD value, the higher is the power of poison. An increase of the pLD value by 1 stands for a tenfold increase in toxicity. The lethal acute dose for water, one of the most important and at the same time non-toxic substances of all, is about one tenth of the body weight. This leads to a possible pLD value for water of 1, an ideal starting value for a logarithmic poison scale.
