胡麻种质资源遗传多样性及亲缘关系的SRAP分析

Genetic Diversity and Phylogenetic Relationship of Flax Germplasm Resources Based on SRAPs

利用SRAP分子标记,对国内外5个不同地区161份胡麻种质资源的遗传多样性及亲缘关系进行研究,为胡麻育种提供科学依据。结果表明:(1)20对引物扩增出307个条带,其中有192个多态性条带,多态比率为62.54%,平均每对引物组合有9.60个多态性位点,每对引物的多态性信息量(PIC)为0.51~0.76,平均为0.61。(2)有效等位基因数(Ne)、香浓信息指数(I)和Neis遗传相似系数(H)在物种水平上分别为1.582 0、0.521 1和0.346 5,在群体水平上分别为1.491 1、0.431 1和0.286 3。(3)各群体遗传多样性指数表现为中国西北群体>中国华北群体>美洲群体>亚洲群体>欧洲群体。(4)聚类分析结果显示,在遗传相似系数为0.335 5处,将161份胡麻资源分为2大类;在0.455 0处,分为5个亚类,与国内外5个不同地区来源吻合。研究表明,中国西北地区胡麻品种(系)的遗传多样性最为丰富;地域是影响胡麻种质资源遗传多样性的主要因素;国内、外品种(系)间的遗传差异较大,表现出较远的亲缘关系。

In order to provide the foundation for flax conventional and molecular breeding,we explored the genetic diversity level of161flax germplasm resources from five different regions of the world,using SRAP molecular marker technology.The results showed that:(1)twenty pairs of SRAP primers produced307bands,of which192polymorphism,with the polymorphic rate of62.54%,and9.60polymorphic loci for each pair of primers.The polymorphism information content(PIC)of each pair of primers ranged from0.51~0.76,with an average of0.61.(2)At the species level,effective number of alleles(Ne),Shannon's information index(I),Nei's genetic similarity coefficient(H)were1.5820,1.5211,and0.3465,respectively;but at the population level,Ne=1.4911,I=0.4311,H=0.2863,with the genetic diversity of northwestern Chinese population being the highest.(3)The order of the populations according to their diversity indices:population from the northwestern China>population from the northern China>American population>Asian population>European population.(4)The clustering analysis results showed that when the genetic similarity coefficient was0.3355and0.4550,the161flax resources could be divided into two major categories and five subgroups,respectively,coinciding with the five different origins in the world.It can be seen from the study that flax cultivars from northwestern China showed the richest genetic diversity,suggesting that growing region was the main factor that had affected the genetic diversity of flax germplasms.There were relatively large distance of genetic relationship between the Chinese varieties and those from abroad.