INTEGRATED PHENOTYPIC, BIOCHEMICAL AND MOLECULAR CHARACTERIZATION OF MUSTARD APHID (LIPAPHIS ERYSIMI) RESISTANCE IN RAPESEED-MUSTARD GENOTYPES

Abstract

Rapeseed-mustard is one of the significant oil seed crops of India but the productivity is limited due to mustard aphid (Lipaphis erysimi). Resistant plants are one of the measures towards sustainable management of aphid. The present study was carryout at Dholi, Bihar on 40 advanced rapeseed–mustard genotypes with two susceptible and resistant checks under natural field infestation during rabi 2022-2023. Aphid population and responses to aphid damage were measured at the flowering and pod formation stages of development and aphid resistance categories were assigned by aphid populations, damage and resistance indices. In addition, selected genotypes were screened for the total phenol and soluble sugar content. In addition, mitochondrial cytochrome c oxidase subunit I (mtCOI) sequencing was used to support the identification of collected aphid specimens. The lowest population of the aphid (41.82) was observed on KMR(E) 21-1 which was considered as Resistant which had almost equivalent value with the resistant check Kranti (43.98). There were 11 moderately resistant genotypes, 25 susceptible and four highly susceptible genotypes. Biochemical estimation showed high negative correlation between total phenol content and aphid infestation index (r = -0.972, p < 0.01), while soluble sugars did not show significant positive correlation. The molecular analysis revealed 98.00-98.04% sequence similarity with Lipaphis erysimi pseudobrassicae. These resultants are useful in testing materials for resistance and integrated mustard aphid management programs.