刺梨杂种F_1代田间抗白粉病的遗传分析初探

A Preliminary Study on Inheritance Tendency of the Resistance to Powdery Mildew Using F_1 Progenies of Chestnut Rose(Rosa roxburghii Tratt)

采用刺梨‘贵农6号’(抗)ב贵农5号’(感)正反交获得的F1代群体,对刺梨白粉病抗性的遗传倾向进行研究。结果表明,F1代杂种的抗病性呈正态分布,正反交群体病情指数的遗传传递力(Ta)明显高于亲中值,广义遗传力(H2)分别为61.0%和60.4%;按病情指数的大小,F1代群体可明显聚为高抗、中抗和感病等3类,经X2检测符合1∶2∶1分离比率,推测抗病性受2对主效基因控制,且非等位基因间存在积加效应,还受多个修饰基因的调控作用。

F_1 progenies of‘Guinong 6’(resistant)בGuinong 5’(susceptible) and their reciprocal cross were used to investigate the inheritance tendency of resistance to powdery mildew disease of chestnut rose(Rosa roxburghii Tratt). The result showed that the disease index of F_1 progenies showed normal distribution.Hereditaries(T_a)of F_1 progenies disease index were significantly higher than mid-parent value, and the broad-sense heretabilities of Guinong 6×Guinong 5 and the reciprocal cross were 61.0% and 60.4% respectively. Based on the disease index, the F_1 progenies of Guinong 6×Guinong 5 could be grouped into three subclusters using UPGMA method, which revealed high resistance, moderate resistance , and susceptibility respectively, and their segregation ratios were 1∶2∶1 by X2 test. These results suggest that the resistance appears to be co-dominated by two types of genetic models:1)Two alleles which show additive effect between them; 2)Multiple genes which contribute to the continued values of disease index in same subcluster.