Mapping Of QTLs For Silk Quality And Non-lepis Wing Gene, Nlw, In Silkworm (bombyx Mori)

Molecular makers are powerful tool in the analysis of genome, which are comprehensively applied in mapping functional genes and molecular breeding of silkworm (Bombyx mori). SSR(Simple sequence repeats)and STS (Sequence-tagged sites) were adopted in this project to map QTLs (Quantitative trait locus) for silk quality and non-lepis wing gene, nlw. Meanwhile, SNP (Single Nucleotide Polymorphisms) makers were employed in mapping analysis of the eighteenth chromosome in the silkworm. The main results as follows:The significant divergence exists in the silk quality of silkworm strains Js and L10. A backcross population (BC1) was bred using Js and L10 as parents. Base on the former experimental data of Zhan et al (2009), there was a QTL located at the first chromosome. A linkage map containing seventeen polymorphic makers was constructed and the QTLs relation to silk characters were mapped.The reciprocal backcrossed F1 (BC1) progenies were constructed using the wild type (+nlw/+nlw) silkworm strain P50 and U06 with scaleless wing (nlw/nlw). The gene of interest was linked to eight SSR markers and one STS marker.A linkage map of 125.7 cM was constructed using a reciprocal BC1M population, and the distance between nlw and the nearest marker cash2p was 11.4 cM.SNP makers were analysed using backcross population (BC1) derived from L10 and Js, and the economical detection platform for SNP were established, which lay the foundation for the mass application of SNP.