Cytogenetics and fiber properties were studied on the Gossypium hirsutumxG. somalense F2 hybrid and later generations. The cytological analyses of pollen mother cells (PMCs) were made at meiotic metaphase I. The resul...Cytogenetics and fiber properties were studied on the Gossypium hirsutumxG. somalense F2 hybrid and later generations. The cytological analyses of pollen mother cells (PMCs) were made at meiotic metaphase I. The results indicated that the hybrid was a new allohexaploid, its chromosome number determined as 2n=6x=78, and genome group as 2[(AD)1E2]. Chromosomal configurations of the hexaploid averaged 0.15Ⅰ+ 38.72Ⅱ + 0.1Ⅲ + 0.02Ⅳ per cell, 85.09% PMCs having 39 bivalents, and only 11.84% PMCs having 1 to 2 multivalents, indicating that heteroge-netic recombinations of chromosomes occurs between (AD)1 and E2, nevertheless, the frequency is lower. The hexaploids are self-fertile and the progenies remain the hexaploids, whose fibers are light brown and have higher strength by measurement of HVI 900 system. The fiber strength increases 42% than that of upland cotton variety. Therefore, it is possible for the hexaploid to be an important germplasm resource to improve fiber strength of cotton.展开更多
After 20 years of systematic studies,15 subfamilies,38 genus and 104 species of braconid wasp in Hunan province are recorded.According to the studies on both male and femal genitalia of Aridelus hunanensis You,Xio...After 20 years of systematic studies,15 subfamilies,38 genus and 104 species of braconid wasp in Hunan province are recorded.According to the studies on both male and femal genitalia of Aridelus hunanensis You,Xiong et Zhou and Aridelus rutilipes Papp,and on both male genitalia of Streblocera flava You et Xiong and Streblocera okadai Watanabe,it is pointed in this paper that Aridelus hunanensis You,Xiong et Zhou and Streblocera flava You et Xiong are still considered valid independent species.This disagrees with Chen X.’s and C.van Achterberg’s (1997) opinion that Aridelus hunanensis You,Xiong et Zhou is a junior synonym of Aridelus rutilipes Papp,and Streblocera flava You et Xiong is the same species of Streblocera okadai Watanabe. Key words:Braconid wasp;taxonomy;fauna;展开更多
基金the Key Project A of the Chinese Academy of Sciences (Grant No. KZ951-A1-101) the special funds for young scientists in life science (Grant No. STZ-00-32).
文摘Cytogenetics and fiber properties were studied on the Gossypium hirsutumxG. somalense F2 hybrid and later generations. The cytological analyses of pollen mother cells (PMCs) were made at meiotic metaphase I. The results indicated that the hybrid was a new allohexaploid, its chromosome number determined as 2n=6x=78, and genome group as 2[(AD)1E2]. Chromosomal configurations of the hexaploid averaged 0.15Ⅰ+ 38.72Ⅱ + 0.1Ⅲ + 0.02Ⅳ per cell, 85.09% PMCs having 39 bivalents, and only 11.84% PMCs having 1 to 2 multivalents, indicating that heteroge-netic recombinations of chromosomes occurs between (AD)1 and E2, nevertheless, the frequency is lower. The hexaploids are self-fertile and the progenies remain the hexaploids, whose fibers are light brown and have higher strength by measurement of HVI 900 system. The fiber strength increases 42% than that of upland cotton variety. Therefore, it is possible for the hexaploid to be an important germplasm resource to improve fiber strength of cotton.
文摘After 20 years of systematic studies,15 subfamilies,38 genus and 104 species of braconid wasp in Hunan province are recorded.According to the studies on both male and femal genitalia of Aridelus hunanensis You,Xiong et Zhou and Aridelus rutilipes Papp,and on both male genitalia of Streblocera flava You et Xiong and Streblocera okadai Watanabe,it is pointed in this paper that Aridelus hunanensis You,Xiong et Zhou and Streblocera flava You et Xiong are still considered valid independent species.This disagrees with Chen X.’s and C.van Achterberg’s (1997) opinion that Aridelus hunanensis You,Xiong et Zhou is a junior synonym of Aridelus rutilipes Papp,and Streblocera flava You et Xiong is the same species of Streblocera okadai Watanabe. Key words:Braconid wasp;taxonomy;fauna;
