Sources of Resistance in Brassica Cultivars Against Aphids: A Review Article

Abstract

Aphids (Hemiptera: Aphididae) constitute one of the most destructive groups of insect pests affecting Brassica crops worldwide. Their damage results from direct phloem sap extraction, secretion of phytotoxic saliva, honeydew-mediated fungal growth, and transmission of economically important plant viruses. Increasing concern over environmental contamination, insecticide resistance, and disruption of beneficial arthropods has intensified interest in host plant resistance (HPR) as a sustainable aphid management strategy. This review presents an in-depth synthesis of resistance and susceptibility in Brassica cultivars against major aphid species, particularly Lipaphis erysimi, Brevicoryne brassicae, and Myzus persicae. Morphological, biochemical, physiological, molecular, and ecological mechanisms underlying aphid resistance are critically analyzed, with emphasis on glucosinolate-mediated defenses, phenolic compounds, oxidative enzymes, signaling pathways, and genetic regulation. Interspecific and intraspecific variability in resistance within the genus Brassica is discussed alongside advances in quantitative trait locus mapping, transcriptomics, and modern breeding approaches. The ecological implications of resistant cultivars on aphid population dynamics and multitrophic interactions are also explored. Finally, key research gaps and future prospects for developing durable aphid-resistant Brassica cultivars under changing climatic conditions are highlighted. This review aims to serve as a comprehensive reference for researchers, plant breeders, and pest management professionals.