野生杏和栽培杏的遗传多样性和遗传结构分析

利用SSR分子标记结合荧光毛细管电泳检测技术,研究了野生杏和栽培杏的遗传多样性和遗传结构,结果显示:27个SSR位点,平均每个位点检测到17.82个等位基因(Na)和7.44个有效等位基因(Ne),平均Shannon's信息指数(I)为2.23,平均期望杂合度(He)和观察杂合度(Ho)分别为0.70和0.52。基于SSR位点,群体水平上平均等位基因数、有效等位基因数、期望杂合度、观察杂合度和Shannon's信息指数分别为6.59、4.15、0.70、0.53和1.50,说明我国杏种质资源遗传多样性丰富,其中野生杏资源遗传多样性明显高于栽培杏资源,野生杏中西伯利亚杏种质遗传多样性最高且具有较多的特异等位基因,而栽培杏中仁用杏遗传多样性最低,特有等位基因较少。聚类分析将供试159份种质分为4组。群体遗传结构分析将159份种质划分为5个类群,分类情况与传统形态指标划分基本一致。通过本研究可知,我国杏资源遗传多样性丰富,遗传结构较为复杂;西伯利亚杏与栽培杏亲缘关系较远;野生普通杏与栽培杏具有类似的遗传结构,推测野生普通杏为栽培杏原始种;仁用杏遗传多样性较低,遗传背景狭窄。本研究结果可为杏资源新品种选育及持续利用提供重要的理论依据。

Genetic Diversity and Population Structure of the wild apricot and cultivation apricot

SSR (simple sequence repeat) markers were chosen for analyzing the genetic diversity and genetic structure of wild apricot, cultivation apricot by the capillary electrophoresis with fluorescence detection. The results were obtained as follows: Seventeen point eight two alleles (Na) and 7.44 effective alleles (Ne) per locus were identified using 27 SSR molecular markers; the average Shannon''s information index (I), expected heterozygosity (He) and observed heterozygosity (Ho) were 2.23, 0.70 and 0.52, respectively. At the population levels, average number of alleles, effective number of alleles, expected heterozygosity, observed heterozygosity and Shannon''s information index were 6.59, 4.15, 0.70, 0.53, and 1.50, respectively, which indicated that a high level of genetic diversity existed in apricot resources in China. The genetic diversity of wild apricot resources were significantly higher than cultivation apricot resources, the highest genetic diversity was Siberian apricot population that had the largest number of private alleles in wild apricot resources, however, the lowest genetic diversity was kernel-using apricot population, which had a few of private alleles in the cultivation apricot resources. The clustering result showed that 159 individuas could be divided into four clusters. Genetic structure analysis showed that 159 individuas divided into five groups, this result was line with the classification of the traditional morphology. At this present study, a high level of genetic diversity and complex population structure existed in apricot resources our country, wild common apricot germplasm and cultivation apricot had a close relatives and a similar genetic structure, it speculated that the wild common apricot was the original species of the cultivation apricot; on the contrary, the kernel-using apricot had a narrow genetic base, and had a low level of genetic diversity. These results also could provide important theoretical basis for the new variety breeding and sustainable utilization of apricot resources.