High-Throughput Screening of Chickpea Genotypes for Dry Root Rot Resistance using a Blotting Paper Method and Image Analysis

AbstractDry root rot (DRR), caused by the necrotrophic fungus Macrophomina phaseolina, is an emerging threat to chickpea (Cicer arietinum L.) cultivation, particularly under drought and high temperature stress. This study employed a high-throughput blotting paper method to screen five chickpea genotypes, alongside one resistant (ICC-4958) and one susceptible (BG 212) check, for DRR resistance. Seven days postinoculation with M. phaseolina, root morphology was assessed using a root scanner, DSLR camera, and stereo microscope. Disease incidence, root necrosis, and microsclerotia presence were quantified. Out of the five genotypes studied, three (ICC 348528, ICC 552241, and ICC 83325) exhibited significant resistance, with minimal root necrosis and low microsclerotia counts whereas, two genotypes viz. ICC 305467 and ICC 95167 suggested partial resistance or susceptibility. ICC 348528, ICC 552241, and ICC 83325 emerge as promising candidates for breeding programs. This rapid, cost-effective screening method offers a robust tool for identifying DRR-resistant chickpea genotypes, facilitating breeding programs for improved disease resistance.