RAPD Marker Analysis of Continuous Divergent Selection in Cross-Bred Population of Wheat (Triticum aestivum L.)
小麦异交群体连续歧化选择的RAPD分析 RAPD Marker Analysis of Continuous Divergent Selection in Cross-Bred Population of Wheat (Triticum aestivum L.)

A base population was established through multi-parent random crossing by using Taigu dominant male-sterile wheat, and then five cycles of 2-way selection for four quantitative characters were conducted.The dynamic changes of genetic structures in the open-pollinated wheat population were examined by RAPD technique.Seven primers in RAPD analysis amplified 116 sites. The results of gene frequencies and phenotypic bands showed abundant genetic variations existed in the population. The percentage of polymorphic loci was 88.79, and the average heterozygosity was 0.3143 in the whole population. The genetic distance of RAPD showed as follows: (1) The genetic distance within a subpopulation was lower than that between every two subpopulations. (2) Each subpopulation had considerable divergence compared with unselected population. (3) The genetic distances between the subpopulations which were selected for plant height gradually increased accompanied with the selection. (4) The genetic distance between subpopulations which were selected for the same character was lower than that were selected for different characters both in the same generation and among different generations.The cluster results of RAPD genetic distance demonstrated that the subpopulations selected for the same character going to one cluster. It also showed that the selective effect of increasing plant height was obvious.