应用频数分布面积法定位家蚕QTL

Mapping QTLs in Silkworm by Distribution Area of Frequencies

利用生态型差异较大的两个家蚕品种782和odl00作正反杂交，得到F1．让F1雄蚕与带双隐性标记的od100回交，得到回交子代．应用频数分布面积定位QTL方法，对家蚕的全茧量和茧层量进行QTL定位．茧层量的一个QTL即q（ω）被定位于性连锁群中标记基因od油蚕一侧的58.14.cM处；全茧量的一个QTL即q（ωc）与sch完全连锁，因此定位于sch基因处．这2种数量性状在测交子代中实际分布与理论分布的吻合表明我们在前文建立的频数分布面积定位方法是有效可行的．

Two silkworm varieties,782 and odl00,which are quite different form each other in ecotype,were positively and oppositely crossed to generate F1.Male silkworm mothes of Fl were crossed with female mothes of od100 with two recessive morphomarkers to generate backcross offspring.The frequent distributions of two quantitative traits,weight of cocoon shell and of cocoon,of backcross offspring in four morphomarker genotypes were made respectively and then the QTLs for these two quantitative traits were mapped by using method of distribution area of frequencies (DAF).The weight of cocoon shell and of cocoon were respectively controlled by a major gene on the sex-linkage group.A QTL for weight of cocoon shell at 58.14cM distance to flank of od gene,and a QTL for weight of cocoon is completely linked with sch gene.The linkage distance between the two morphomarkers,sch and od is 20.2cM.The fact that the various actual distribution patterns of frequencies of these two quantitative traits in backcross(testcross)offspring were identical with the expectant distribution of frequencies implicates that the DAF method is useful for mapping QTLs using two morphmarkers.