棉花开放花蕾性状的遗传及其在杂优利用中的应用

棉花开放花蕾主要来源于种间杂交的后代。我国将这一性状称作雌雄异熟系或柱头外露,为便于学术交流,本文建议应与国际上的称法相一致,即开放花蕾。开放花蕾是两对隐性重叠基因所控制,陆地棉与海岛棉均为单节隐性基因纯合体,但基因型不同,各带有一对位点不同的隐性基因。开放花蕾在棉花杂种优势利用中具有应用潜力。尤其是带有低酚标志性状的开放花蕾系“E-81”,有助于提高制种效率。开放花蕾性状的雌、雄蕊发育进度,在减数分裂前是不同步约,但减数分裂后雌配子体的发育速度加快,最舌达到雌、雄配子体同步成熟。 当花柱外露长度达6～7mm时,柱头的生理活性强,是杂交制种中授粉的有利时期。开放花蕾的天然异交率最高为100％,最低为40％,平均达80．4％。

Inheritance of Cotton's Open-Bud and its Application in Heterosis

Lines with trait of open bud was bred from the generations of interspecific hybridization mainly. Male and female parents with different maturity or open style such as the trait was proposed specially in China .In order to international academic exchange, suggestion was named that the trait of male and female parents with different maturity. would be named "open bud". The trait of open bud was due to different two pairs of duplicate recessive genes. The two sets of interspecific parents were homozygous stocks for monomeric recessive genes. Application of open bud to heterosis in cotton breeding has potential. Specially, open bud line with the trait of glandless E-81 was very useful to produce hybrid seeds .The development of pistil and stamen in cotton line with open bud was not synchronous before meiosis .The stages of development of pistil and stamen were gradually synchronous after meiosis. The physiological activity of the pollen was the highest when the length of external stigma period of pollination. This was the optimal period of pollination. Naturally crossing percentage for lines with the trait of open bud was 80.47%, ranging 40% to 100%.