The rice water weevil, Lissorhoptrus oryzophilus Kuschel, has two generations in southern Zhejiang, China. To determine oogenesis in first-generation females (summer females) and its relations to temperature, female...The rice water weevil, Lissorhoptrus oryzophilus Kuschel, has two generations in southern Zhejiang, China. To determine oogenesis in first-generation females (summer females) and its relations to temperature, females were collected from a rice field in early and mid-July and reared on young rice plants at 28, 31 and 34 ℃ in the laboratory. Percentage of females having oocytes, number of oocytes of different stages (stage-Ⅰ, from early previtellogenesis to middle vitellogenesis; stage-Ⅱ, late vitellogenesis; and matute-oocyte stage), and length of ovarioles were determined every 10 d of feeding. At each temperature, oogenesis took place in over 40% of females after 20-40 d of feeding, but only 0.0-3.3 stage-Ⅰ, 0.0-0.8 stage-Ⅱ and 0.0-1.1 mature oocytes were observed at each observation date. Temperature had significant effect on number of stage-Ⅰ oocytes but not on number of stage-Ⅱ and mature oocytes in early July females; temperature had no significant effect on number of oocytes of either stage in mid-July females. Conclusively, in southern Zhejiang, summer L. oryzophilus females have great potential to become reproductive on rice, but their oogenesis activity is very low, with the overall procedures little affected by temperature.展开更多
The rice water weevil,Lissorhoptrus oryzophilus Kuschel(Coleoptera:Curculionidae),reproduces by sex in the Southeastern United States,but reproduces by parthenogenesis in California and other invaded regions in Asia a...The rice water weevil,Lissorhoptrus oryzophilus Kuschel(Coleoptera:Curculionidae),reproduces by sex in the Southeastern United States,but reproduces by parthenogenesis in California and other invaded regions in Asia and Europe.The objective of this study was to create a parthenogenetic gene expression profile of the rice water weevil in order to gain a better insight into the molecular mechanisms of parthenogenesis in the weevil.Suppression subtractive hybridization(SSH) technique was employed for profiling differential gene expression in the developed ovary between the parthenogenetic and bisexual female rice water weevils.A total of 70 contigs were obtained,and the BLASTX search identified putatively 28 genes with differential functions.According to the cytological process of parthenogenesis,the tubulin alpha-1 chain and signal transduction genes etc.were selected for real time quantitative RT-PCR analyses,and their possible functions related to the molecular mechanism of parthenogenesis were discussed.The tubulin alpha-1 chain and some signal transduction genes may be related to the molecular mechanisms of parthenogenesis of the rice water weevil.展开更多
基金Project supported by the National Natural Science Foundation of China (No. 30400290) and the National Basic Research Program(973) of China (No. 2002CB111403)
文摘The rice water weevil, Lissorhoptrus oryzophilus Kuschel, has two generations in southern Zhejiang, China. To determine oogenesis in first-generation females (summer females) and its relations to temperature, females were collected from a rice field in early and mid-July and reared on young rice plants at 28, 31 and 34 ℃ in the laboratory. Percentage of females having oocytes, number of oocytes of different stages (stage-Ⅰ, from early previtellogenesis to middle vitellogenesis; stage-Ⅱ, late vitellogenesis; and matute-oocyte stage), and length of ovarioles were determined every 10 d of feeding. At each temperature, oogenesis took place in over 40% of females after 20-40 d of feeding, but only 0.0-3.3 stage-Ⅰ, 0.0-0.8 stage-Ⅱ and 0.0-1.1 mature oocytes were observed at each observation date. Temperature had significant effect on number of stage-Ⅰ oocytes but not on number of stage-Ⅱ and mature oocytes in early July females; temperature had no significant effect on number of oocytes of either stage in mid-July females. Conclusively, in southern Zhejiang, summer L. oryzophilus females have great potential to become reproductive on rice, but their oogenesis activity is very low, with the overall procedures little affected by temperature.
基金Supported by the National Key Basic Research and Development Program of China (Grant No. 2009CB119200)National High Technology Research and Development Program of China (Grant No.2007AA10Z220)Key Projects in the National Science & Technology Pillar Program in the Eleventh Five-year Plan Period (Grant No.2006BAD17B06)
文摘The rice water weevil,Lissorhoptrus oryzophilus Kuschel(Coleoptera:Curculionidae),reproduces by sex in the Southeastern United States,but reproduces by parthenogenesis in California and other invaded regions in Asia and Europe.The objective of this study was to create a parthenogenetic gene expression profile of the rice water weevil in order to gain a better insight into the molecular mechanisms of parthenogenesis in the weevil.Suppression subtractive hybridization(SSH) technique was employed for profiling differential gene expression in the developed ovary between the parthenogenetic and bisexual female rice water weevils.A total of 70 contigs were obtained,and the BLASTX search identified putatively 28 genes with differential functions.According to the cytological process of parthenogenesis,the tubulin alpha-1 chain and signal transduction genes etc.were selected for real time quantitative RT-PCR analyses,and their possible functions related to the molecular mechanism of parthenogenesis were discussed.The tubulin alpha-1 chain and some signal transduction genes may be related to the molecular mechanisms of parthenogenesis of the rice water weevil.
基金The research work was supported by the State"973"Program (Grant No.TG2000016210),the Chinese Academy of Sciences (Grant No.kscx2-sw-103) and National Natural Science Foundation of China (Grant No.30170158).