家蚕茧层练减率的遗传和育种学的研究

本试验对家蚕茧层练减率进行了遗传及育种学的研究,结果表明,不同化性间、不同系统间,不同品种间以及品种内雌雄性间的茧层练减率均有很显著差异,茧层练减率与全茧量,茧层量,茧层率的相关关系没有一致倾向,按海曼(Hayman)模型估算出茧层练减率的遗传参数为: D=1.8341、H_1=0.2793、H_2=0.2690、F=-0.0798;在茧层练减率的遗传成分中,以加性成分为主,茧层练减率显性效应由一个或一组不完全显性的主效基因控制;茧层练减率的广义遗传力为91.16％狭义遗传力为82.21％。茧层练减率的一般配合力间以及特殊配合力间差异很显著。茧层练减率一般情况下表现为负向杂种优势,通过用系统育种法和杂交育种法对茧层练减率进行选择试验,表明选择有效,但以杂交育种法更为理想。

STUDIES ON THE HEREDITY AND BREEDING OF THE DEGUMMING IOSS OF COCOON SHELL OF BOMBYX MORI

This experiment deals With the Studies on degummibng loes of cocoon shell of Boabyx mari in terms of heredity and breeding ,and the results showed that there were differences between the various voltines,varieties and male and female silkworms among the same variety.There was no uniform tendency for the cotelation between the degumming loss of cocoon shell and whole cocoon weight,cocoon shell weight and cocoon shell ratio According to the estimation by Heymen model,the pararameters of degumming lossS of cocoon shell were D=1.8344.H1=0.2793,H2=0.2690.F=0.0798;in the besedicery cemponents of degumming loss of cocoon shell.additive componeat was the major one;ist derminant effect was controled by an iacomplese dorminat,major gene or by a group of them;its generalized heretability was 91.16%.while its special one was 82.21%.There was a significant difference between its general combining ability and apecial conbinging ability.Generally,it appeared to be negative to heterosis.Through the systemic hreeding and hybridisation in the selection test of degumming loss of cocoon,it was known that selection was effective,And the more idealistic method was to use the latter oae