甘蓝耐热性遗传效应分析

Inheritance Effect of Heat Tolerance in Cabbage

选用2个耐热的甘蓝亲本(3A,5A)和3个不耐热的亲本(1A,11A,8A)按Griffing完全双列杂交设计方法Ⅱ,配制出15个杂交组合用于配合力分析。结果表明,在总的遗传变异中,代表加性遗传效应的一般配合力方差占绝大部分,而特殊配合力方差比例很小,仅占总变异的4％,显性效应不显著。以两组耐热和不耐热的亲本材料(5A×1A,3A×8A)分别进行杂交、回交和自交,连同双亲获得P1,P2,F1,F2,B1,B2共6个世代的试验材料进行耐热性遗传模型分析和遗传参数的估算。结果表明,该性状符合加性-显性-上位性遗传模型,以加性效应为主,兼有上位性效应,显性效应不显著,广义遗传力和狭义遗传力均较高。因此在耐热育种中单纯利用杂交优势试图获得超亲优势来显著提高耐热性是不现实的,而应该注重耐热亲本的定向选择。

Two heat tolerant cabbage parents and three sensitive ones were used to analyze the combination of heat tolerant character by the way of Griffing's Ⅱ. It suggests that GCA is superior to SCA in the whole heredity and variation. That is to say, the dominant effect of heat tolerant character in cabbage is not significant, and the additive effect is most important. Two groups of heat tolerant and intolerant materials were crossed ,back crossed, and self crossed to analyze the inherited models and parameters of this character. The results show that the character abides by the inheritance model of A- D- E, its hB2 and hN2 are also is much higher. So it is not practical to improve the heat resistance significantly in breeding by heterosis, but it is supposed to select the heat tolerant parent in breeding.