玉米温-热种质杂交后代选系遗传结构的SSR标记分析

Analysis of Genetic Structure of Selected Lines from Temperate Zone×Tropical Zone Maize by SSR Marker

利用SSR标记技术,对温热种质5003×A19杂交F6、F7后代性状基本稳定的22个选系遗传结构进行了初步研究。从88对SSR引物中,筛选出48对表现多态性丰富、带型清晰明显且稳定的引物,分析了22个选系的遗传多样性及遗传结构,并对其应用前景进行了探讨。根据SSR标记结果,用UPG-MA法进行聚类分析表明,双亲及其杂交后代全部选系与标准测验种478、B73属于同一个杂种优势群-PA群,玉米温热种质杂交后代选系虽然出现了丰富的遗传变异,但在类群划分上仍然保持双亲的基本类群特征。从基于SSR分子标记的各选系遗传组成分析,温带种质(5003)遗传背景明显高于热带种质(A19),在各选系中温带种质5003遗传背景平均含量为64.03%、A19遗传背景平均含量为30.03%、非双亲遗传背景平均含量为5.94%;SSR标记分析显示,在温-热带种质杂交后代的多数选系中均出现新的等位基因,且通过多代选择仍是有效的,说明温热种质杂交群体有广泛的遗传变异基础,是玉米种质扩增、改良的有效途径。

Using SSR-PCR molecular technique,the genetic structure of 22 selected lines from F6 and F7 generations from 5003 × A19 were analyzed.In this study,48 out of 88 pairs of SSR primers were selected,which gave stable and polymorphic amplification profiles in focus.The UPGMA analysis classified 22 selected lines and their parentes into the same cluster-PA,which included standard-testers 478 and B73.The average genetic background of 22 selected lines had 64.03% from temperate zone maize 5003,30.03% from tropical zone maize A19,and 5.94% not from parentes.The result showed,some new alleles were tested in some lines.This is a availably approach of maize germplasm enhancement improvement.