【摘要】 采用RAPD分子标记、遗传距离和聚类分析方法 ,研究建国以来我国有代表性的 16 6个棉花主栽品种 (或品系 )的遗传多样性。 4 1个RAPD标记Nei’s遗传距离 (GD)与两组不同来源实验数据的表型性状欧氏距离 (UD)间相关系数分别为 0 6 4 4 5 (n =1770 )和 0 70 78(n =714 0 ) ,表明RAPD可以揭示棉花品种间遗传差异。通过对不同棉种、不同品种类型、不同时期、不同种植区域和不同来源的棉花品种 (系 )遗传差异的比较 ,探讨我国棉花品种的遗传基础。各层次上遗传差异的比较表明 :在我国主栽棉花品种中 ,海岛棉品种遗传基础窄于陆地棉品种 ;我国自育陆地棉品种的遗传基础窄于国外引进品种 ;杂交陆地棉品种的遗传基础窄于常规品种 ;上世纪 80年代以后陆地棉品种遗传基础窄于 70年代品种 ;长江棉区品种遗传基础窄于黄淮棉区品种 ,西北内陆棉区品种窄于长江棉区品种。启示我们如何在我国棉花育种的全局和不同层面上把握和制定拓宽棉花育种遗传基础的策略和手段 ,并为进一步深入探讨建国以来我国棉花品种遗传改良规律打下基础更多还原

【Abstract】 The diversity of 166 cotton cultivars(cult.) including 159 upland( G.hirsutum L) and 7 island( G.barbadense L) ones planted mainly in China since 1949 was explored by RAPD,genetic distance(GD) and cluster analysis.The correlation coefficients between Nei’s GD of RAPDs and two groups of phenotype data’s Euclidean distances (UD) were 0 6445(n=1770) and 0 7078(n=7140),which indicated that RAPD could be used to explore genetic diversity among cotton cultivars in China.The genetic basis of cotton cultivars in China was studied by comparison among different cotton species,different cultivar types,different history periods,different growing regions and different sources.The results showed as follows:within cotton cultivars planted in China,the genetic basis of island cotton cultivars was narrower than that in upland ones;the genetic basis of cultivars released in China since 1949 was narrower than that of introduced ones from outside of China;the genetic basis of hybrids was narrower than that of conventional cultivars(Conv.Cult.);the genetic basis of upland cultivars after 1980 was narrower than that in 1970’s;the genetic basis of cultivars in Changjiang cotton region was narrower than that of Huanghuai cotton region,northwestward cotton region was the narrowest.From which some strategies for breeding,especially for the methods of widening the genetic basis of China cotton cultivars,could be understood and withdrawn.更多还原