Host plant resistance mechanisms in chickpea against pod borer Helicoverpa armigera

Abstract:

Across South Asia, Helicoverpa armigera destroys 20-40% of chickpea pods each season despite heavy insecticide use. Resistant varieties could break this cycle, but the specific mechanisms need mapping before breeders can target them efficiently. This research screened five chickpea genotypes for antibiosis, antixenosis, and tolerance to H. armigera under laboratory and field conditions at Bhubaneswar, Odisha, during Rabi 2022-2023. ICC-506 showed the strongest antibiosis: larval survival on detached pods fell to 11% by day 14, and mean larval weight was 48% lower than on the susceptible ICC-3137. Trichome density on pods of ICC-506 was 8.7 per mm² versus 3.1 in ICC-3137, and oxalic acid content was 3.82 mg g^-1 compared with 1.68 mg g^-1. Pod damage under open-field conditions was 12.4% on ICC-506 versus 38.7% on ICC-3137. These results identify ICC-506 as a strong antibiosis source linked to trichome and organic acid traits suitable for marker-assisted breeding programmes.