杂色鲍×盘鲍杂交及亲本自繁群体的AFLP分析

AFLP Analysis on Populations of Hybrid and Pure Crosses of Haliotis diversicolor and H. discus discus

应用AFLP技术研究了杂色鲍(SS)、盘鲍(JJ)及其正反交群体(SJ和JS)的遗传关系,并比较了各群体内的遗传多样性.3对选择性引物共扩增出344个位点.双亲自繁群体SS和JJ的AFLP图谱差异很大,平均遗传距离达1.425.因此,AFLP图谱可以用于两物种及其杂交种的种质鉴别.正反交群体SJ与JS的AFLP图谱很接近于母本自繁群体,平均遗传距离分别为0.111(SJ与SS之间)和0.134(JS与JJ之间),而与父本自繁群体则有较大区别,平均遗传距离分别达1.408(SJ与JJ之间)和1.394(JS与SS之间).将4个群体分为SS/SJ和JS/JJ两组,进行三水平的AMOVA分析,结果显示:84.74%遗传变异来源于母本不同的两组之间(SS/SJ组和JS/JJ组之间),12.66%变异存在于群体内个体之间,正反交群体与母本之间的变异仅有2.60%.另一方面,正反交F1群体的多态性位点比例、Nei′s遗传多样度、香农多样性指数均低于母本自繁群体.综合群体内多样性和群体间遗传关系分析结果,杂色鲍与盘鲍正反交F1的遗传物质组成有别于同时含有双亲基因组的实质性杂交,而与母本有着高度的遗传同质性,且遗传多样性水平略低于母本自繁群体.

In this paper,genetic relationship iter-populations and genetic diversity intra-populations from reciprocal hybrid and pure crosses of Haliotis diversicolor（S） and H. discus discus（J） were investigated with AFLP. Totally,344 loci were detected with 3 pairs of selective primers. AFLP could be served as a tool to distinguish genetic materiel of Haliotis diwersicolor, H. discus discus and their hybrid, since the AFLP band patterns of SS population and JJ population were quite different. The genetic distance between SS and JJ populations were calculated as 1. 425. The AFLP band patterns of hybrid F1 were similar to those of the female parent but quite different from those of the male parent. The mean genetic distances between hybrid F1 and their female parent were 0. 111（between SJ and SS） and 0. 134 （between JS and JJ）,while those between hybrid F1 and their male parent were 1. 408 （between SJ and J J） and 1. 394 （between JS and SS） respectively. The results of AMOVA analysis showed that 84.74% of variance was between two groups （with different female parent）, 12.66% of variance was among individuals in groups,and only 2.60% of variance was between hybrid population and female population. On the other hand, all examined diversity indexes of the hybrid populations, including of the proportion of polymorphie loci, Nei＇s genetic diversity and Shannon diversity index, were lower than those of the population from pure cross of female parent. Above all,the hybrid F1 were different from true hybrid composed of genome from both parent,but shared high genetic similarity with their female parent.