This study used Trichogramma japonicumto to control Chilo suppressalis （Walker） and Cnaphalocrocis medinalis（Guenée）, and tested the effects of different control methods on main rice pests, natural enemies an...This study used Trichogramma japonicumto to control Chilo suppressalis （Walker） and Cnaphalocrocis medinalis（Guenée）, and tested the effects of different control methods on main rice pests, natural enemies and rice yield. The results revealed that the parasitism of Trichogramma japonicum in the eggs of Chilo suppressalis （Walker） and Cnaphalocrocis medinalis （Guenée） reached 60.3% and 57.1%, and the control efficacy was up to 70.8 % and 91.99%, respectively. The control efficacy for Cnaphalocrocis medinalis （Guenée） was much better. This biological control method could be equivalent to chemical control method in the control effects on main pests in rice. The yield under the biological control was 26.5% higher than that of the control group, and the biological control had a signifcant increase in the number of natural enemies such as spider, up to 400 per 100 plants. Therefore, the sustainable prevention and control were achieved in the presentence with natural enemy organism.展开更多
Objective] The main biological effects of leaf rol ing of rice was studied to provide the theoretical basis for the application of RL （t） in the breeding of the rice. [Method] A rice mutant with adaxial y-rol ed lea...Objective] The main biological effects of leaf rol ing of rice was studied to provide the theoretical basis for the application of RL （t） in the breeding of the rice. [Method] A rice mutant with adaxial y-rol ed leaf was found in breeding, temporarily named as RL （t）. The differences were researched in which light interception struc-ture, light transmission photosynthetic efficiency and cel ular structure comparison between RL （t） and its sister lines that had flat leaf. [Result] Both leaf rol ing index and leaf erecting index of RL （t） were higher than those in 0731-3-1-1B. However, its basic leaf angle and leaf drooping angle were significantly lower than those in 0731-3-1-1B in upper three leaves, which caused a great raise in the photosynthetic rate on account of the light transmittance of RL （t）’s population were significantly higher than that of 0731-3-1-1B especial y the upper and middle part. The stomata conductance and the intercel ular CO2 concentration of the upper three leaves and transpiration rate of the flag and the second leaf were also significantly higher than that of 0731-3-1-1B. The bul iform cel s became smal er, leading to the rol ing up of leaves. [Conclusion] The study provided a theoretical basis for the principle of high-yielding breeding with the application of the adaxial y-rol ed leaf mutant in rice.展开更多
The impacts of transgenic Bt rice on target pests and their predators need to be clarified prior to the commercialization of Bt rice.In this study,the percentages of folded leaves of three transgenic Bt rice lines and...The impacts of transgenic Bt rice on target pests and their predators need to be clarified prior to the commercialization of Bt rice.In this study,the percentages of folded leaves of three transgenic Bt rice lines and non-transgenic parental rice line caused by Cnaphalocrocis medinalis were studied over two successive growing seasons.In addition,the population densities,relative abundance and population dynamics of C.medinalis and four species of its natural arthropod predators were investigated at three sites in China.The results showed that rice line significantly affected the percentages of folded leaves and population densities of C.medinalis larvae.Significantly higher percentages of folded leaves were observed on the non-transgenic rice compared with the three transgenic Bt rice on most sampling dates.Significantly higher densities of C.medinalis larvae and higher relative abundance of C.medinalis within phytophages were found on non-transgenic rice compared with three transgenic Bt rice at different sites across the study period.The population dynamics of C.medinalis larvae were significantly affected by rice line,rice line×sampling date,rice line×year,rice line×sampling date×year.However,there was little,if any,significant difference in the relative abundance,population density and population dynamics of the four arthropod predators between the three Bt rice lines and non-transgenic rice.The results of this study indicate that the Bt toxin in transgenic Bt rice can effectively suppress the occurrence of C.medinalis,but has no significant effects on the occurrence of the four predatory arthropod species.展开更多
文摘This study used Trichogramma japonicumto to control Chilo suppressalis （Walker） and Cnaphalocrocis medinalis（Guenée）, and tested the effects of different control methods on main rice pests, natural enemies and rice yield. The results revealed that the parasitism of Trichogramma japonicum in the eggs of Chilo suppressalis （Walker） and Cnaphalocrocis medinalis （Guenée） reached 60.3% and 57.1%, and the control efficacy was up to 70.8 % and 91.99%, respectively. The control efficacy for Cnaphalocrocis medinalis （Guenée） was much better. This biological control method could be equivalent to chemical control method in the control effects on main pests in rice. The yield under the biological control was 26.5% higher than that of the control group, and the biological control had a signifcant increase in the number of natural enemies such as spider, up to 400 per 100 plants. Therefore, the sustainable prevention and control were achieved in the presentence with natural enemy organism.
文摘Objective] The main biological effects of leaf rol ing of rice was studied to provide the theoretical basis for the application of RL （t） in the breeding of the rice. [Method] A rice mutant with adaxial y-rol ed leaf was found in breeding, temporarily named as RL （t）. The differences were researched in which light interception struc-ture, light transmission photosynthetic efficiency and cel ular structure comparison between RL （t） and its sister lines that had flat leaf. [Result] Both leaf rol ing index and leaf erecting index of RL （t） were higher than those in 0731-3-1-1B. However, its basic leaf angle and leaf drooping angle were significantly lower than those in 0731-3-1-1B in upper three leaves, which caused a great raise in the photosynthetic rate on account of the light transmittance of RL （t）’s population were significantly higher than that of 0731-3-1-1B especial y the upper and middle part. The stomata conductance and the intercel ular CO2 concentration of the upper three leaves and transpiration rate of the flag and the second leaf were also significantly higher than that of 0731-3-1-1B. The bul iform cel s became smal er, leading to the rol ing up of leaves. [Conclusion] The study provided a theoretical basis for the principle of high-yielding breeding with the application of the adaxial y-rol ed leaf mutant in rice.
基金supported by National Genetically Modified Organisms Breeding Major Project:Technology of Environmental Risk Assessment on Transgenic Rice (Grant No. 2008ZX08011-001)
文摘The impacts of transgenic Bt rice on target pests and their predators need to be clarified prior to the commercialization of Bt rice.In this study,the percentages of folded leaves of three transgenic Bt rice lines and non-transgenic parental rice line caused by Cnaphalocrocis medinalis were studied over two successive growing seasons.In addition,the population densities,relative abundance and population dynamics of C.medinalis and four species of its natural arthropod predators were investigated at three sites in China.The results showed that rice line significantly affected the percentages of folded leaves and population densities of C.medinalis larvae.Significantly higher percentages of folded leaves were observed on the non-transgenic rice compared with the three transgenic Bt rice on most sampling dates.Significantly higher densities of C.medinalis larvae and higher relative abundance of C.medinalis within phytophages were found on non-transgenic rice compared with three transgenic Bt rice at different sites across the study period.The population dynamics of C.medinalis larvae were significantly affected by rice line,rice line×sampling date,rice line×year,rice line×sampling date×year.However,there was little,if any,significant difference in the relative abundance,population density and population dynamics of the four arthropod predators between the three Bt rice lines and non-transgenic rice.The results of this study indicate that the Bt toxin in transgenic Bt rice can effectively suppress the occurrence of C.medinalis,but has no significant effects on the occurrence of the four predatory arthropod species.
