Identification of DNA markers linked to H2 locus of fusarium wilt resistance in chickpea (Cicer arietinum L.)

Abstract

Resistance to chickpea wilt caused by Fusarium oxysporum f.sp. ciceris race 1 is governed by two to three genes. The DNA marker linked to H1 locus is already available. In order to identify DNA marker linked to H2 locus of wilt resistance, the recombinant inbred lines derived from the cross K 850 (late wilting) x WR315 (resistant), segregating for only H2 locus were utilized. The recombinant inbred lines showed 1:1 segregation for late wilting and resistance. Seventynine random oligonucleotide primers of 10 to 11 base pairs were used to study the polymorphism in parents. The primer A07C amplifies an extra band of 417 bp in susceptible parent and co-segregate in susceptible bulk. The DNA marker A07C417 showed monogenic segregation ratio of 1:1 in the recombinant inbred lines. The linkage analysis indicated that the A07C417 marker is linked to H2 locus and susceptibility and were separated by 21.7 centi Morgan (eM). The RILs of another cross JG-62 x WR-315 segregate for both H1 and H2 loci; consequently the DNA markers linked to H1 and H2 also showed independent segregation in the RILs of a cross JG-62 x WR-315. The A07C417 marker was also found linked to H2 locus of wilt susceptibility in different genotypes tested. The DNA marker A07C417 showed linkage with H2 locus across genetic backgrounds.The identification of DNA markers linked to both H1 and H2 of wilt resistance will facilitate markerassisted selection and pyramiding of resistance genes to susceptible varieties.