Association of ISSR and ISSR-RGA Markers with Powdery Mildew Resistance Gene in Mungbean

Abstract

Background: Powdery mildew (PM) possesses a wide range of host plants, including mungbean that causes severe yield reductions. Using resistant varieties is an economically and environmentally effective approach in controlling the disease. Methods: In this study, the genetic basis of inheritance and marker loci for PM resistance were investigated using 126 F2:9 recombinant inbred lines (RILs) raised from resistant and susceptible parents, V4785 and CN72, respectively. PM reaction in these RILs was visually scored from natural infection in the field and the segregation pattern was determined by the chi-square test (x2). Result: The results revealed the segregation ration of 1:1, indicative of a dominantly inherited resistance gene controlling resistance against PM in V4785. Observation of potential polymorphism in two parents and two different bulks, each containing 10 RIL individuals showing either the highest resistance or susceptibility, identified 2 and 37 putatively linked inter-simple sequence repeat (ISSR) and ISSR-anchored resistance gene analog (ISSR-RGA) markers, respectively. Of these, 1 ISSR and 3 ISSR-RGA markers were stably inherited and linked to PM resistance (P<0.01). These linked marker systems may prove useful for facilitating the improvement of a durable resistant variety through marker-assisted selection in mungbean breeding programs.