Biochemical basis of Lipaphis erysimi (Kalt.) growth and development in Brassica juncea

Indian mustard, Brassica juncea holds distinction of being second most significant contributor to the production of edible oilseeds in India. This crop encounters nearly 50 distinct kinds of insect pests. Among the several pest species, Lipaphis erysimi (Kaltenbach), commonly known as the mustard aphid, is responsible for causing substantial yield losses. The behaviour, development, and reproduction of aphids can be impacted by the nutritional composition of different plant components. Genotypes, within and between different species of Brassica(s), encompass a range of diversity and, thus, exhibiting varying levels of resistance to mustard aphids. The biochemical composition of different plant parts in mustard, such as leaves, buds, and siliqua, can exert a range of effects on infestation by L. erysimi. Specific dietary components have the capacity to allure aphids and promote their population growth. On the other hand, additional elements such as glucosinolates or other defense compounds exhibit the capacity to deter aphids. Therefore, the study was planned to elucidate the intrinsic constitutive and aphid-induced biochemical defense mechanisms in B. juncea and examine the impact on L. erysimi. Among 30 genotypes, it was observed that TN 3, EC 61-9-2-2-2, NPJ 50, Rohini, IC 355399, RLC 3, and Kranti exhibited elevated levels of biochemical components, reduced preference by aphids, and a significant increase in aphid induced biochemical contents. The impact of these modifications on the behaviour and establishment of L. erysimi was also examined. Overall, the biochemical constituents identified in B. juncea and elaborated their effect on growth and development of L. erysimi are suggested to be effectively employed for breeding Indian mustard genotypes with in-built resistance to L. erysimi.