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
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.
