基于SSR标记构建甜玉米群体的核心种质

Construction of a Core Collection of Sweet Corn Populations Based on SSR Markers

利用40对SSR引物分别分析56份超甜玉米和88份普甜玉米群体材料,基于非加权算术平均配对法（UPGMA）聚类分析和位点优先取样法,分别筛选出14个超甜玉米核心材料和19个普甜玉米材料作为两个亚群体种质。t测验表明,两个亚核心种质与原始群体的等位变异无显著差异（P〉0.05）,等位变异保留率分别为87.81%和89.13%,有效地保留了原始材料群体的遗传变异。两个亚群核心种质与原始材料群体13个表型性状的均值、标准差、极差、变异系数和Shannon-Weaver多样性指数（H’）的平均符合率都在80%以上,并且均值差异百分率（MD）和方差差异百分率（VD）均小于20%,极差符合率（CR）和变异系数变化率（VR）均大于80%,符合核心种质的质量评价标准。构建的甜玉米核心种质最大程度地保留了原始群体的遗传多样性和表型变异,能够有效地代表原始甜玉米材料群体。

Fifty-six super sweet corn populations and eighty-eight sweet corn populations were clusteredbased on 40 SSR primers, respectively. According to allele preferred sampling strategy, two sub-core collectionswere constructed. One was super sweet core collection with 14 materials, another one was sweet corn collection with19 materials. The comparison of allelic variation, two sub-core collection showed no significant difference to its ini-tial collection（P0.05） with reserving ratio of SSR alleles 87.81% and 89.13%, respectively. The average coinci-dence rates of the mean, standard deviation, variation coefficient（CV）, range and Shannon-Weaver diversity index（H＇） between each sub-core collection and its initial collection were all more than 80%. Furthermore, the mean dif-ference percentage（MD） and variance difference percentage（VD） between each-core collection and its initial collec-tion were all less than 20%, and the coincidence rate of range（CR） and the variable rate of coefficient of variation（VR） were all more than 80%. Totally, the core collection including 33 sweet corns retained most genetic diversity ofthe initial collection, which can effectively representing the initial sweet corn collection.