籽用美洲南瓜种质遗传多样性分析及SSR指纹图谱构建

Genetic diversity analysis and SSR fingerprinting of seed-use pumpkin(Cucurbita pepo L.)germplasm

利用20对SSR引物分析48份籽用美洲南瓜种质的遗传多样性并建立指纹图谱,为籽用美洲南瓜种质的亲本选配、保护和鉴定提供依据。结果显示,这20对引物在48份籽用美洲南瓜种质中扩增出115条具有多态性的等位基因,位点的Shannon信息指数(I)均值为1.36、遗传多样性指数(H)均值为0.69、多态性信息指数(PIC)均值为0.63。聚类分析显示,20对SSR引物可将48份种质从0.659相似系数水平上分成两大类。其中,第Ⅰ类包含46份种质,在遗传相似系数为0.679处又将其分为3个亚类。第一亚类包含来自内蒙古巴彦淖尔市的15份种质和来自甘肃的18份种质,第二亚类包含来自新疆的10份种质,第三亚类包含来自山西的3份种质。第Ⅱ类包含了来自内蒙古呼伦贝尔市的2份种质。综合各项指标筛选出5对SSR核心引物将48份籽用美洲南瓜种质完全区分并构建了指纹图谱。

Twenty pairs of SSR polymorphic primers with good polymorphism and clear bands were used to analyze genetic diversity of 48 seed-use pumpkin(Cucurbita pepo L.)germplasm by fingerprinting for the purpose of parent selection,protection and identification.115 polymorphic bands were amplified from the 48 pumpkin germplasm.The average Shannon’s information index(I)was 1.36,the average genetic diversity index(H)was 0.69,the average polymorphism information content(PIC)was 0.63.Cluster analysis showed that 48 accessions could be divided into two categories from the level of 0.659 similarity coefficient.The first category includes 46 accessions under three subclasses at the genetic similarity coefficient of 0.679.The first subclass has 15 accessions from Bayannur City,Inner Mongolia and 18 accessions from Gansu,the second subclass has 10 accessions from Xinjiang and the third subclass has 3 germplasms from Shanxi.The second category includes two accessions from Hulunbuir,Inner Mongolia.Five pairs of core SSR primers were selected based on diversity indexes.Forty-eight pumpkin germplasm were completely distinguished using fingerprinting based on the five core SSR primer pairs.