崖城系列甘蔗亲本遗传多样性的AFLP标记分析

AFLP Analysis of Genetic Diversity in Series Sugarcane Parents Developed at HSBS

采用15对多态性较好的AFLP引物对52份崖城系列甘蔗亲本品系的遗传多样性进行分析,结果表明,每对引物的多态性位点平均为61.40,多态性位点率为77.30%。52份材料的遗传相似系数在0.4832-0.9614之间,平均为0.6806,遗传多样性属中等水平。来自同一组"合CP72-1210×崖城82-108"品系的遗传相似性系数很高,在0.7836-0.8398范围内,平均是0.8117。以遗传相似系数阈值约为0.6700划分,聚类分析把52份材料分为5大类,系谱记录中亲缘关系密切的品系,大多数都能归为同一类。不同年代品系的遗传多样性指数差异明显,最高是20世纪90年代,为0.3155,最低是20世纪的50-70年代,为0.2654;来自相一组合的后代品系遗传多样性指数较低。建议在亲本创新过程中,同一亲本不宜过多重复使用。

Genetic diversity in 52 sugarcane parent materials developed at Hainan Sugarcane Breeding Station was studied using 15 pairs of AFLP primers. The results showed that the average polymorphic loci each primer pairs were 61.40, and the percentage of polymorphism loci was 77.30%. The genetic similarity indexes （GSI） of 52 parents varied from 0.483 2 to 0.961 4, with an average of 0.680 6, which implied that the genetic diversity among the parents bred by HSBS was at a middle level. Among the clones from the same cross of ＂CP72-1210× YC82-108＂ there were high GSI values ranged from 0.783 6 to 0.839 8, with an average of0.S11 7. The 52 parents were clustered into five groups at the GSI value of 0.670 0. Most of the clones with close relationship in family-trees could be classified into same sub-groups. The parents bred in different periods showed remarkable differences in genetic diversity indexes （GDI）. The ones selected in 1990s were found to be the most diverse （GDI=0.315 5） and the 1950-1970s the least （GDI=0.265 4）. GDI of the clones from the same cross was low. It is suggested that the same clone should not be overused as parents in breeding new parental materials.