Role of biophysical factors imparting resistance in inter-specific chickpea genotypes against Helicoverpa armigera (Hübner)

Abstract

Effect of trichome density and length on leaves and pods of seven interspecific chickpea genotypesalong with two check cultivars ICCL 86111 and L 550 were evaluated during rabi 2015-16. Two types of trichomes, glandular and non glandular, were observed on both leaves and pods. Highest non-glandular trichomedenisty was observed on leaves in GLW 8 (73.67 trichomes per mm) while lowes number of glandular trichomes on pods in GLW 32 (15.67 trichomes per mm2). The pod wall thickness in test genotypes varied from 0.32 to 0.44mm. Highest and lowest pod wall thickness was found in the susceptible check L550 (0.49 mm) and GLW 131 (0.32 mm) respactivily. Longer non-glandular trichomes on leaves were observed in genotype GLW 32 (299.00 µm) and minimum trichome length in genotype GLW 131 (169.00 µm). Glandular trichome length on leaves ranged from 187.55 to 313.09 µm in various test genotypes andlarger trichome was observed in GLW 32 (313.09 µm). The mean length of glandular trichomes on pods ranged from 286.67 to 434.00 µm. Genotypes GLW 32 (434.00 µm) had recorded longest trichome (at par with GLW 8 433.67 µm).