QTL Aanalysis Of Resistance To Storage Pest Sitophilus Zeamais In Wheat And The Expression Assay Of Its Digest Genes

Quantitative trait loci (QTLs) associated with Sitophilus zeamais resistance were identified using a population (127recombined inbred lines) from wheat cross Chuannong16×Chuanmai42. In a stimulated storage environment, adult, larva, and egg of S. zeamais were artificially fed with wheat seeds harvested in2008and2009, respectively. Five QTLs located on chromosomes3B,2D,3D, and4B were detected with phenotypic contributions of10.2%,8.5%,8.3%,8.5%, and11.3%, respectively. The QTLs located between Xbarc6and Xgwm112on chromosome3D were identified in seeds from both growing years, which explained8.3-8.5%of the phenotypic variance. The positive allele on this locus was originated from Chuannong16. Digestive gene sequences of S. zeamais including Asp, Cys, a-Amy were cloned and their sequences contain189bp,223bp and204bp, respectively. EF-la and PRPG were considered as housekeeping genes to assay the expression levels of those genes. Three wheat lines (NO.1-23,1-31,1-46) with resistance to S. zeamais and3lines (NO.1-100,1-105,1-110) with susceptible to S. zeamais were screened out to inoculation with ovum of S. zeamais. After S. zeamais ate the seeds of6wheat strains were screened out above, digestive genes of S. zeamais were analyzed in different time period and wheat strains. The result showed that digestive genes of S. zeamais were different between three resistance lines and three susceptible lines, indicating that three resistance lines (NO.1-23,1-31,1-46) had some inhibiting factors of digestive enzyme with resistance to S. zeamais, while three susceptible lines (NO.1-100,1-105,1-110) had little inhibiting factors of digestive enzyme with susceptible to S. zeamais.