[Objective] The study aimed to understand the mutagenic effects of space flight on alfalfa seeds.[Method] Seeds of three lines of alfalfa were carried into orbit by the satellite 'Shijian-8' for space fight,th...[Objective] The study aimed to understand the mutagenic effects of space flight on alfalfa seeds.[Method] Seeds of three lines of alfalfa were carried into orbit by the satellite 'Shijian-8' for space fight,the indices including seed germination rate,plant height and growth rate,were measured after the seeds been retrieved.[Result] Remarkable mutagenic effects occurred on the flight seeds,which were mainly presented by abnormal cotyledon,extended variation range of plant height and growth rate.Nineteen plants with increased plant height were preliminarily screened from the T0 progenies,but whether the mutated trait could inherit should be confirmed in further study.Three flight lines of alfalfa are different in the percentages of abnormal cotyledon(10%-18%),variation range of plant height(increased 30%-150% compared to control),selected plant number with increased plant height(5-7 plants),suggesting that differences exits between the three lines in mutation efficiency.[Conclusion] Valuable mutated materials could be obtained by space flight and applied in modern agriculture.展开更多
In this paper, we prove that （L^X,5） is T0,T1, T2, regular （T3）, normal （T4） and completely regular spaces if and only if （R（L）^X, ω（δ）） is T0, T1, T2, regular （T3）, normal （T4） and completely regula...In this paper, we prove that （L^X,5） is T0,T1, T2, regular （T3）, normal （T4） and completely regular spaces if and only if （R（L）^X, ω（δ）） is T0, T1, T2, regular （T3）, normal （T4） and completely regular spaces, respectively, and （L^X,δ） is N-compact if and only if （R（L）^X, ω（δ）） is N-compact.展开更多
基金Supported by Special Fund on Fundamental Scientific Research as Operating Expenses among Commonweal Scientific Research Institutions at Na-tional Level(Grassland Research Institute,Chinese Academy of Agricultur-al Sciences)National Key Project of Scientific and Technical Supporting Programs Funded by Ministry of Science & Technology of China(2008BADB3B04)~~
文摘[Objective] The study aimed to understand the mutagenic effects of space flight on alfalfa seeds.[Method] Seeds of three lines of alfalfa were carried into orbit by the satellite 'Shijian-8' for space fight,the indices including seed germination rate,plant height and growth rate,were measured after the seeds been retrieved.[Result] Remarkable mutagenic effects occurred on the flight seeds,which were mainly presented by abnormal cotyledon,extended variation range of plant height and growth rate.Nineteen plants with increased plant height were preliminarily screened from the T0 progenies,but whether the mutated trait could inherit should be confirmed in further study.Three flight lines of alfalfa are different in the percentages of abnormal cotyledon(10%-18%),variation range of plant height(increased 30%-150% compared to control),selected plant number with increased plant height(5-7 plants),suggesting that differences exits between the three lines in mutation efficiency.[Conclusion] Valuable mutated materials could be obtained by space flight and applied in modern agriculture.
基金Foundation item： the National Natural Science Foundation of China （No. 10471083） the Natural Science Foundation of Zhejiang Education Committee （No. 20060500）.
文摘In this paper, we prove that （L^X,5） is T0,T1, T2, regular （T3）, normal （T4） and completely regular spaces if and only if （R（L）^X, ω（δ）） is T0, T1, T2, regular （T3）, normal （T4） and completely regular spaces, respectively, and （L^X,δ） is N-compact if and only if （R（L）^X, ω（δ）） is N-compact.
