Molecular mapping of locus controlling resistance to Helicoverpa armigera (Hubner) in Cajanus cajan L. (Millspaugh) using interspecific F2 mapping population

Abstract

Pod borer, caused by Helicoverpa armigera (Hubner), is an important agronomic pest of pigeonpea. Genetic analysis for resistance to H. armigera in an interspecific F2 population and a set of F3 families both derived from a cross between Cajanus cajan cv. ICP-26 (Susceptible) and C. scarabaeoides acc. ICPW-94 (Resistant) revealed that the resistance is controlled by a dominant allele at a single locus. Pod borer resistance is associated with non glandular short trichomes, which is also governed by a dominant allele at a single locus. The resistance locus (PPB1) was mapped by linkage analysis with 32 random amplified polymorphic DNA (RAPD) loci, and six inter simple sequence repeat (ISSR) loci segregating among the F2 population. The PPB1 locus was mapped to the linkage group 2 (LG-2) and was flanked by ISSR marker loci UBC8731270 (15.9 cM), and the non glandular short trichome (NGST) locus (12.0 cM) and OPA18565 (26.3 cM). The presence of only few double recombinants between UBC8731270 and NGST (4.31 %) and PPB1 and OPA18565 (10.34 %) in the F2 population indicated that the simultaneous use of both the markers along with morphological trait NGST would be useful in introgression of pod borer resistance gene into C. cajan background and pigeonpea breeding programme.