Genotypic reaction and biochemical basis of resistance in sunflower against leafhopper

Field experiment was conducted during Rabi 2024-2025 to screen 23 sunflower genotypes along with susceptible check, Morden to evaluate their reaction against sunflower leafhopper at the field of Oilseeds Research Unit, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola. Field screening of 23 sunflower genotypes revealed that, three genotypes AKSFI-6R, LH/AR/PM-7-8 and CFSI 5082-2 were categorized as ‘Resistant’ genotypes with Mean Scale Index ranging from 0.8 to 1.0. Fifteen genotype GPN 219-2, ID-1079, GMU-490, AKSFI-148, LH-23-41, AKSFI 21-13, AKSFI-218, AKSFI-214, RHF 138-2R, 6-D-1R, 189/1R, RB -9-1, LH/AR/PM-1, RB-7-1and LH/AR/PM-2, were found as ‘Moderately Resistant’ with Mean Scale Index ranging from 1.2 to 2.4 and two genotypes GP6442 and RB-4-2 were found susceptible with Mean Scale Index ranging from 2.6 to 3.5. The biochemical constituents phenol (r=- 0.744) and tannin (r=-0.871) showed negative significant correlation with leafhopper infestation, suggesting their defensive role. In contrast, chlorophyll (r=0.836), nitrogen (r=0.808) and protein (r=0.807) showed a positive significant correlation with leafhopper infestation, implying a possible susceptibility factor, therefore, phenolic, tannin, chlorophyll and nitrogen compounds could serve as key biochemical markers for identifying leafhopper resistance sunflower genotypes.