Preliminary report on quantitative trait loci mapping of false smut resistance using near-isogenic introgression lines in rice

Abstract

After analyzing the graphical genotypes for 266 near isogenic introgression lines (NIILs) in Teqing background using 146 molecular markers selected from the constructed linkage map of Lemont/Teqing RILs, and combined with the results of natural identification of false smut resistance in the field for two years, quantitative trait loci (QTLs) underlying false smut resistance was preliminarily mapped using graphical genotypic overlapping method. Results indicated that the total genetic distance of 146 markers was 2 227.6 cM, which covered 96.6% genome of the recurrent parent with the average distance of 15.2 cM for neighboring markers. Two QTLs, QFsr10 and QFsr12, on the chromosomes 10 and 12 were mapped through trait marker correlation analysis and graphical genotypic overlapping, whose positive alleles at the two loci were all derived from Lemont with the additive effects of 3.38 and 3.34 scale respectively. The characteristic and effect of QTL mapping using graphical genotypic overlapping method were discussed.