贵州70份玉米自交系的SSR标记遗传多样性及其杂种优势群分析

Genetic Diversity and Heterotic Group of 70 Maize Inbred Lines in Guizhou by SSR Marker

从251个SSR标记中筛选出均匀分布在玉米基因组上的88个SSR标记,用以分析评价贵州省2000年以来47个审定品种的70份亲本材料的遗传多样性。SSR标记检测的结果:88个标记共检测出466个等位基因,每个标记可检测等位基因2～18个,平均为5.31个;每个标记位点的多态性信息量(PIC)变化为0.213～0.965,平均为0.586,这表明贵州玉米自交系具有较为丰富的遗传多样性。POPTREE聚类分析结果:70份自交系分为Ⅰ、Ⅱ和Ⅲ类群。Ⅰ类群含8个自交系,以瑞德和兰卡斯特等温带种质为主。Ⅱ类群有11个自交系,以PN78599、瑞德和兰卡斯特等温带种质为主。Ⅲ类群拥有51个自交系,可分为A和B 2个亚群,B亚群还可再分为B1和B2 2个次亚群,A亚群中的10个系以我国地方温带种质为主,B1次亚群中的19个系以贵州地方亚热带种质为主,B2次亚群中的22个系以泰国苏湾热带种质为主。杂种优势利用分析的结果表明,贵州近些年在玉米育种中,主要是利用贵州地方亚热带种质和泰国苏湾热带种质2个杂种优势群,这与其多态位点百分率较高有关,与其群内SSR位点的平均等位数较多有关。贵州玉米育种利用的种质类型较少,有必要加强玉米种质的扩增、改良与创新研究。

Genetic diversity of 70 parental inbred lines of 47 maize hybrids authorized in Guizhou province since 2000 was analyzed by using 88 simple repeat sequence（SSR）markers equably distributed in genome and screened from 251 SSR markers through whole genome.466 alleles were detected across 88 SSR loci;5.31（2-18）per locus,averagely.The average polymorphic information content（PIC）was 0.586（0.213-0.965）per locus.All above showed that the genetic diversity of inbred lines tested was relatively plentiful.The 70 inbreds could be classified into three groups by POPTREE software（Windows version）.The 1st Group included 8 inbred lines mainly with temperate germplasm of Reid,Lancaster,etc..The 2nd Group had 11 inbreds mainly with temperate germplasm of PN78599,Reid,Lancaster,etc..The 3rd Group possessed 51 lines,and could be sorted into A and B sub-group which the latter could be divided into B1 and B2 sub-sub-groups.A Sub-group with 10 lines had chiefly temperate local germplasm.B1 Sub-sub-group with 19 lines bore basically sub-tropical local germplasm of Guizhou,and B2 Sub-sub-group with 22 lines tropical Suwan germplasm from Suwan Farm in Thailand.Analysis of hybrid vigor utilization indicated that two heterotic groups of B1 and B2 were principally applied to maize breeding in Guizhou during the recent decade,relating to high percentage of polymorphic loci and allelic mean number of SSR loci within B1 and B2.It is necessary to reinforce researches of germplasm enhancement,improvement and innovation in that the less of germplasm types used in Guizhou.