关键词: 甘蓝, 结球甘蓝, SSR标记, 杂种优势, 遗传距离, 聚类分析, 预测

Abstract:

SSR markers were used to analyze the genetic diversity of 23 spring cabbage and 29 autumn cabbage inbred lines. The results showed that the 23 spring cabbage inbred lines were classified into two major groups,namely the extremely early maturing group and the early maturing group at the genetic similarity coefficient of 0.61. Meanwhile,twenty-nine inbred lines of autumn cabbage were classified into three groups,namely middle-late maturing,middle-early maturing,and middle maturing group. Fifteen inbred lines were selected to make 105 hybrid combinations with complete diallel method to analyze their heterosis and explore the relationship between genetic distance and heterosis by SSR markers. At the genetic similarity coefficient of 0.58,the heterosis analysis of 105 hybrid combinations obtained from 15 parental materials meant that the offspring produced by crosses among different groups or between different subgroups of the same group had stronger heterosis. Coefficient among genetic distance based on polymorphism of SSR markers and gross weight mid-parental heterosis was significant at 0.01 level. Thus,the classification based on SSR markers had a certain value for heterosis prediction. In addition,this study also found that among 105 hybrid combinations,the 10 combinations with the strongest mid-parental heterosis among gross weight was spring cabbage × autumn cabbage,indicating that the combination of spring cabbage × autumn cabbage had a potential utilization on heterosis breeding.

Key words: cabbage, SSR marker, heterosis, genetic distance, cluster analysis, prediction