基于SCoT分子标记的61份加工型黄瓜种质资源遗传多样性分析及DNA指纹图谱构建

Genetic diversity analysis and DNA fingerprinting construction of 61 processed cucumber germplasm resources based on SCoT markers

为探明加工型黄瓜种质资源的亲缘关系及遗传多样性,为新品种选育提供理论依据,采用目标起始密码子多态性标记(SCoT)技术,以61份加工型黄瓜种质资源为试验材料,进行遗传多样性分析并构建DNA指纹图谱。结果表明,从100条SCoT引物中筛选出8条扩增条带清晰、多态性高且重复性好的引物;利用筛选出的引物对61份黄瓜种质基因组DNA进行PCR扩增,共扩增出238个位点信息,其中多态性位点227个,平均多态性位点百分比为95.38%;采用NTSYS-pc 2.1软件计算得出供试的61份材料间的遗传相似系数分布在0.588~0.920之间,遗传相似系数最小的材料分别是34号与55号,二者在瓜色、叶片形状及果实形状方面存在较大差异,说明两者亲缘关系最远。基于遗传相似系数对其进行UPGMA聚类分析和树状图绘制,在相似系数0.735处,可将其划分为7个类群,说明61份黄瓜种质材料背景存在差异,但多数地域来源相近、生境相似地区的种质被聚在同一类群。利用2对特异性较大的引物SCoT12和SCoT83构建的DNA指纹图谱可单独鉴别出61份黄瓜种质资源,该图谱可为黄瓜分类与鉴定提供科学依据。

In order to find out the genetic diversity of germplasm resources of processed cucumber and provide theoretical basis for the breeding of new varieties.the genetic diversity of 61 processed cucumber germplasm resources was analyzed and DNA fingerprinting was constructed using SCoT technique.The results showed that 8 primers with clear amplifica-tion bands,high polymorphism and good repeatability were selected from 100 SCoT primers.A total of 238 loci of 61 cu-cumber germplasm genomic DNA were amplified by PCR using the selected primers,of which 227 were polymorphic lo-ci,and the average percentage of polymorphic loci was 95.38%.NTSYS-pc 2.1 software was used to calculate the distri-bution of genetic similarity coefficients among the 61 tested materials between 0.588 and 0.920,and the material with the smallest genetic similarity coefficients was 34 and 55,respectively.There were great differences in melon color,leaf shape and fruit shape,indicating that the two were most loosely related.Based on the genetic similarity coefficient,UPG-MA cluster analysis and tree diagram were performed.At the similarity coefficient 0.735,they could be divided into 7 groups.The results indicated that 61 cucumber germplasm material backgrounds were different,but most of the germ-plasm sources were similar,and germplasm from similar habitats were grouped together in the same group.Sixty-one cu-cumber germplasm resources could be identified by DNA fingerprinting of SCoT 12 and SCoT 83,which could provide scientific basis for classification and identification of cucumber.