香蕉引进品种遗传关系的微卫星检测

应用SSR标记技术,对33个香蕉引进品种(系)和1个国内品种的遗传关系进行了检测.40对SSR引物在34个品种(系)中扩增带数在4～17个之间,平均每个SSR座位可检测3.05个多态性带;引物的多态信息量(PIC)在0.21～0.91之间,平均0.78.依据SSR数据计算的品种问遗传距离在0～45.53%之间,平均28.19%,说明引进的香蕉品种之间存在较为丰富的遗传变异.UPGMA聚类分析将34个品种分为A基因组和AB基因组为主的2大品种类群.检测出多个与我国早期引进的主栽品种巴西蕉和Williams遗传差异突出的引进品种,这为筛选鉴定出新的替代品种,以及进一步在不同类群品种之间进行杂交选育新的品种奠定了基础.洪都拉斯3号与M931之间,洪都拉斯1号和洪都拉斯2号之间没有区分开来,它们可能分别是同一克隆,或者是同一克隆的突变体.

Analysis of Genetic Diversity among Exotic Varieties of Bananas using SSR Markers

SSR markers were used to assess the genetic diversity among 33 exotic varieties and 1 indigenous variety of banana. All microsatellite loci were found polymorphic among all the varieties. The number of alleles per locus ranged from 4 to 17 when scoring was restricted to strongly amplified fragments, and an average of 3.05 polymorphic alleles per locus was detected. The average polymorphism information content(PIC) was 0.78, ranging from 0.21 to 0.91. The average pairwise genetic distances among varieties were estimated to be 0.00 %~45.53 % with an average of 28.19 %, which revealed a wide range of variability among them. In the light of the genetic distance by SSR data, the cluster analysis with unweighted pair-group method using arithemetic averages produced two major clusters that closely corresponded with the genome composition of the varieties (A genome and their hybrids between A genome and B genome). Many exotic varieties were observed to have significant genetic difference from the popular cultivars of Williams and Brazil Jiao, and will be utilized in banana production as new cultivars and banana breeding as parents. Honduras 3 and M 931 were found identical, as well as Honduras 1 and Honduras 2. They might be from a clone or a clonal mutant.