A Genetic Treasure Trove: Wild Relatives and Landraces in the Genomic Era of Indian Mustard (Brassica juncea)

Abstract

Indian mustard (Brassica juncea L.) holds significant agronomic value globally, particularly across South and Southeast Asia, where it is cultivated both as an oilseed and leafy vegetable crop. However, breeding efforts in B. juncea have been hindered by its relatively narrow genetic base, a consequence of repeated selection for a limited number of traits over generations. This genetic bottleneck compromises its adaptability and increases susceptibility to various biotic and abiotic stresses. Recent advancements in genomics, molecular breeding, and the strategic use of wild relatives offer promising avenues for enhancing genetic variability and improving key agronomic traits. This review highlights the crop’s domestication history, its diverse gene pool encompassing landraces and wild relatives, and recent progress in hybrid development, QTL mapping, and marker-assisted selection. Emphasis is placed on the untapped potential of wild relatives in conferring improved stress tolerance, disease resistance, and enhanced nutritional content. Integrating molecular tools with emerging pan-genomic datasets and high-throughput phenotyping platforms can accelerate the development of climate-resilient, high-yielding B. juncea cultivars. Therefore, the systematic exploration and incorporation of underutilized genetic resources hold the key to sustainable mustard improvement in the face of evolving environmental challenges.