Identifying QTLs for Thermo - tolerance of Amylose Content and Gel Consistency in Rice

摘要

A mapping population of 98 backcross inbred lines (BILs) derived from a backcross, Nipponbare/Kasalath//Nipponbare, was used to identify the quantitative trait loci (QTL) conferring the thermotolerance of amylose content and gel consistency in rice. The thermotolerance was evaluated with the heat tolerance index of amylose content (HTIAC) and gel consistency (HTIGC) (HTIAC = amylose content at high temperature/ amylose content at low temperature x 100, HTIGC = gel consistency at high temperature/ gel consistency at low temperature x 100). The main, epsitatic and QTL by environment interaction effects were analyzed by a mixed - linear model approach, A total of nine QTLs including three QTLs for thermotolerance of amylose content and six QTLs for thermotolerance of gel consistency were detected in Nanchang and Nanjing. Three QTLs for these two traits were common in two experimental locations and 2 of which showed significant QTL by environment interaction effect. Only one epistatic interaction with small effect was detected for thermotolerance of amylose content. While thirteen pairs of epsitatic interaction involving one main - effect QTL were identified for thermotolerance of gel consistency. The amount of variation explained by epista-sis was smaller than that explained by the main - effect QTL. No common epistatic interaction was detected in both experimental locations. The same region as Wx locus on chromosome 6 and interval of G1073 -R727 on chromosome 8 were important regions for the thermotolerance of amylose content and gel consistency respectively.