Abstract:

【Objective】 This study aimed at detecting quantitative trait loci (QTL) responsible for adult resistance against wheat yellow rust. 【Method】 In this study, a recombinant inbred line (RIL) population derived from a cross between Neixiang 188 and Yanzhan 1 was evaluated for adult-plant resistance (APR) in two years under field conditions using AUDPC (Area Under Disease Progress Curve, AUDPC) and IT (Infection Type, IT). 【Result】 Nine additive QTLs and seven pairs of epistatic QTLs were detected based on the composite interval mapping. Among them, five additive QTLs and two pairs of epistatic QTLs showed QTL×environment interactions (QEs). Two QTLs, QYr.caas-3D and QYr.caas-6A, were both detected using either AUDPC or IT data. The total QTL effects based on AUDPC data explained 62.05% phenotype variation, with 44.32% additive effects, 17.73% epistatic effects, and 0.42% QEs. Using IT data, the total QTLs explained 37.53%, with 23.94% additive effects, 10.51% epistatic effects, and 3.08% QEs. 【Conclusion】 The loci of adult plant resistance to yellow rust were identified not only in resistant parent Neixiang 188, but also in susceptible parent Yanzhan 1. QYr.caas-3B and QYr.caas-6D were two new loci responsible for the resistance to yellow rust disease. The interaction could occur between two loci without resistance.

Key words: wheat, yellow rust, QTL, epistatic interaction