Indian Journal of Entomology

This study evaluates the biochemical basis of resistance to mustard aphid Lipaphis erysimi (Kaltenbach) in Brassica genotypes under semiarid conditions of Haryana. The study was carried out during rabi 2016-17 at the research area and laboratory of Oilseeds Section, Department of Genetics Plant Breeding, CCS Haryana Agricultural University, Hisar. Ten genotypes belonging to Brassica spp., viz., B. campestris (BSH-1), B. carinata (HC-212), B. juncea (Purple Mutant), B. tournefortii (DRMR-2205), B. napus (HNS- 9605), B. nigra (Nigra), B. rapa L. var. toria (Sangam), B. rapa L. var. yellow (YSH-401), E. sativa (T-27) and Sinapsis alba (DRMR-2183) were included. Observations on the L. erysimi at flower initiation, full flowering and full pod formation/ setting stages and aphid infestation index (AII) was computed. These data were correlated with biochemical parameters such as total phenols, sugars, proline content and leaf waxes. The genotypes viz., BSH-1, YSH-401 and HC-212 were observed with very low phenol content (1.51, 1.60 and 1.85%, respectively). The AII and total phenols were observed significantly negatively correlated (r=-0.92**). The effect of waxes in leaves had a lethal effect (AII vs leaf waxes correlation being significantly negative with r = -0.91**). AII was observed significantly positively correlated with proline content (r =0.91**) and total sugar content (r= 0.98**). Regression analysis revealed that the biochemical contents collectively accounted for 97% variability in aphid infestation.