香蕉A基因组品种间遗传关系的SSR检测

应用SSR技术,对32个香蕉A基因组类型品种(系)的遗传关系进行了检测。40对SSR引物在32个品种(系)中分别扩增带数在3～15个,平均每个SSR座位可检测2.99个多态性带;引物的多态信息量(PIC)在0.00～0.88,平均0.62。依据SSR数据计算的品种间遗传距离在0.00%～34.27%,平均12.45%,大多数品种间的遗传变异非常有限,但也存在着遗传差异突出的品种:FHIA25、Yangambi KM5、Pisang Jari Buaya、Rose和皇帝蕉。依据26%的遗传距离,除了FHIA25和Pisang Jari Buaya单独化成1组外,其它30个品种可以分为2组:品种间遗传差异相对较高的组I和品种间遗传差异相对较低的组Ⅱ。Williams与引进的洪都拉斯3号、M931之间,洪都拉斯1号和洪都拉斯2号之间,高脚青芽蕉和高脚顿地雷分别没有区分开来,这可能是同物异名,也可能是同一品种未能分辨的突变体。

Analysis of genetic diversity of A genome among banana cultivars using SSR markers

The total of 40 SSR markers was used to assess the genetic diversity among 32 banana cultivars with A genome. All microsatellite loci were polymorphic among cultivars. 3 to 5 polymorphic bands were amplified respectively from 32 cultivars with 40 pairs of SSR primers,with an averaged 2.99 polymorphic bands per locus. The polymorphism information content (PIC) ranged from 0.00 to 0.88 and averaged 0.62. The averaged pair wise genetic distances among cultivars were estimated from 0.00% to 34.27% with an average of 12.45%,which revealed a narrow range of variability among cultivars,except for FHIA 25,Yangambi KM 5,Pisang Jari Buaya,Rose and Huangdijiao. Based on the genetic distance of 26% by SSR data,the cluster analysis with un-weighted pair-group method using arithmetic averages produced 2 major clusters: cluster I of higher degrees of genetic differentiation and Cluster Ⅱ of lower degrees of genetic differentiation relatively,which are composed of 30 cultivars,and another cluster of much higher degrees of genetic differentiation,which is only composed of the cultivars of FHIA 25 and Pisang Jari Buaya. SSR analysis failed to distinguish among Williams,Honduras 3 and M 931,between Honduras 1 and Honduras 2,and between Gaojiaoqingyajiao and Gaojiaodundilei,which may be caused by synonyms or the little-differentiated variants to one identical cultivar.