Morphological and Biochemical Bases of Resistance of Some Groundnut Germplasms against Tobacco Caterpillar, Spodoptera litura (Fabricius) and Leaf Miner, Aproaerema modicella (Deventer)

A screening experiment of forty germplasm lines was conducted at College Farm, College of Agriculture, Rajendranagar, Hyderabad in rabi, 2019-20 and was laid in Randomized block design (RBD) having two replicates. Three germplasm lines viz., ICGV 16679 (13.71% leaf damage), ICGV 07222 (14.00% leaf damage) and ICGV 93468 (14.25% leaf damage) showed greater resistance than the resistant check, ICGV 86031 (15.04% leaf damage) against tobacco caterpillar and with respect to resistance against leaf miner, no germplasm line was found to be superior than the resistant check, ICGV 86031 (7.82% leaf damage). However, the germplasm line, ICGV 02266 (8.35% leaf damage) was next best to the resistant check. The various morphological and biochemical characters were recorded and correlated with insect pest damage and incidence to know their role in imparting resistance/susceptibility. Resistance to various insect pests in germplasm lines was due to significantly higher trichome density on leaf lamina, higher phenol and tannin content.