Genetic evidence for resistance to Fusarium wilt of pollen grains in chickpea (Cicer arietinum L.)

In the present study, we have investigated the possibility that genes conferring wilt resistance in chickpea determine the resistance at both sporophyte and gametophyte phases. The wilt resistance of 16 diverse genotypes was determined using an in vitro screening technique. The presence of resistance genes in these genotypes was confirmed using molecular markers linked to resistance loci. Increased concentrations of the pathotoxin, fusaric acid, in the pollen germination medium inhibited pollen tube growth of chickpea under in vitro conditions. The inhibition was more in susceptible early wilting genotypes compared to the susceptible late wilting. The tube growth inhibition was least in resistant genotypes. The degree of pollen tube growth inhibition was influenced by the number of resistance alleles that it contained. The resistant pollen grains had resistance alleles at both h(1) and h(2) loci, while the susceptible pollen grains had none as that of sporophytic resistance. The evidence of pollen performance on the number of resistance allele(s) in the pollen indicates the potentiality of pollen selection for wilt resistance in chickpea. The study demonstrated that pollen bioassay can be used to select resistance of pollen grains, and consequently the genotype of the sporophyte producing pollen grains.