家蚕对质型多角体病毒感染抵抗性研究——Ⅱ.家蚕对质型多角体病毒感染抵抗性的配合力及遗传力

试验以二化性品种为A组,以含多化性血统的二化性品种和多化性品种为B组,采用不完全双列杂交法配制32个组合(正、反交),估算家蚕对中肠型脓病抵抗性的配合力,遗传力.结果表明:亲本间抵抗性的一般配合力相对效应值,32个组合特殊配合力相对效应值差异达显著、极显著水准;亲本一般配合力相对效应值在含多化性血统的二化性品种及多化性品种之间的差异大于二化性品种之间的差异;组合特殊配合力相对效应值在同一品种的正反交中和同一品种与不同品种杂交中表现均不同;群体配合力方差分析,正交中一般配合力方差(Vg%)达76.63,特殊配合力方差(Vs%)为23.37.反交中一般配合力方差(Vg%)是45.12,特殊配合力方差(Vs%)为54.88.前者加性作用明显,后者非加性作用突出一些,遗传力的分析,正交广义遗传力为87.84%,狭义遗传力67.32%,反交广义遗传力97.06%,狭义遗传力43.79%,加性作用减弱,推测在抵抗性遗传中尚存在若干主效基因,彼此间有显性、上位等作用.

Studies on Resistance of Bombyx mori Larvae to CPV.——Ⅱ. Combining Ability and Heritability

With 4 bivoltine strainsas group A and 4 strains of bivoltinism, with their ancestry of multivoltinism, or of multi-voltinism as group B, 32 crosses were made according to a diallel mating design to evaluate the combining ability and heritability of resistance of silkworm larvae to CPV. The result showed that the relative effect values of the general combining ability (GCA) among parents and the special combining ability (SCA) among crosses were significantly different. The differences of the relative effects of the GCA among multivoltine strains and bivoltine strains containing multivoltine pedigrees were larger than those among bivoltine strains. The reciprocal crosses as well as the crosses of one of these strains outcrossed with other stra ins gave different values in the relative effect of SCA of the same strains. Moreover, diallel analysis showed that the variance of GCA(Vg% ) was 76.63%, the value of SCA (Vs% ) was 23.37. In the reciprocal crosses the variance for GCA ( Vg% ) was 45.12, and the variance for SCA (Vs%) was 54. 88. Therefore, the former showed an obvious additve effect and the latter gave a non-additive effect. The broad sense heritability ( BSH ) was 87.84% and the narrow sense of heritability ( NSH ) was 67.32%. But in the reciprocal crosses, BSH was 97.06%, NSH was 43.79%.