几个家蚕性连锁平衡致死系与限性斑纹母本的配合力测定

以限性斑纹品系Y7、JS、MC为母本,性连锁平衡致死系sd2、px2、YH4、8、12和YH18为父本,采用不完全双列杂交法测试分析家蚕性连锁平衡致死系的配合力。结果表明,不同家蚕性连锁平衡致死系的配合力不同,同一家蚕性连锁平衡致死系不同性状间的配合力也存在一定的差异。其中:性连锁平衡致死系18的万蚕产茧量和万蚕茧层量的一般配合力效应值最高,分别为2.83和3.07;雄蚕杂交组合Y7×YH18的万蚕产茧量的特殊配合力效应值最高(为4.32),Y7×YH8的万蚕茧层量的特殊配合力效应值最大(为5.08);而MC×sd2在万蚕产茧量和万蚕茧层量方面的配合力总效应值均为最高(分别为9.92和8.96)。以配合力效应值为选择依据,筛选出产茧量和茧层量预期较高的雄蚕杂交组合MC×sd2,实验室饲养结果表明,该组合的综合性状优良,茧丝生产性能较好。

Determination of Combining Ability Between Several Silkworm Sex-linked Balanced Lethal Lines and Sex-limited Dapple Female Parents

The combining ability of sex-linked balanced lethal lines was tested and analyzed by means of incomplete diallel cross design using the sex-limited dapple strains Y7,JS and MS as female parents and the sex-linked balanced lethal lines sd2,px2,YH4,YH8,YH12 and YH18 as male parents.The results indicated that the combining ability among different sex-linked balanced lethal lines was different,and the combining ability between different traits of the same sex-linked balanced lethal lines also had certain difference.Among them,the cocoon yield per 10 000 larvae and the cocoon shell weight per 10 000 larvae of the sex-linked balanced lethal line YH18 had the highest effect value in general combining ability,which was as high as 2.83 and 3.07 respectively.The cocoon yield per 10 000 larvae of male silkworm hybrid combination Y7×YH18 had the highest effect value(4.32) of special combining ability.The cocoon shell weight per 10 000 larvae of male silkworm hybrid combination Y7×YH8 showed the highest effect value(5.08) of special combining ability.And the total effect values of combining ability either in cocoon yield per 10 000 or cocoon shell weight per 10 000 of MC×sd2 were the highest(9.92 and 8.96 respectively).Based on selection criteria of combining ability effect values,MC×sd2,a male silkworm hybrid combination,was found to have the expected high levels in cocoon yield and cocoon shell weight.Data of rearing practice in laboratory showed that this hybrid combination had excellent comprehensive traits and good cocoon and silk productivity.