Advances in Breeding for Oil Quality Enhancement in Indian Mustard (Brassica spp. L.): Achievements, Challenges, and Research Opportunities

Major objectives in oil crop improvement are enhancement of seed and oil yield, quality of oil according to its use, i.e. edible or industrial uses, breeding of varieties that fit in different cropping systems and breeding biotic and abiotic stress resistant/tolerant varieties. Despite traditional breeding approaches, including pure line breeding, yielding only modest gains in productivity, recent advancements in mustard breeding have led to significant breakthroughs in both productivity and oil quality. This review discusses the innovative breeding strategies that have contributed to these advancements, with a focus on hybrid development, oil quality enhancement, and biotechnological approaches. To enhance productivity, researchers at the University of Delhi have developed hybrid seed production techniques using transgenic Barnase-barstar systems and cytoplasmic male sterility (CMS) systems. These systems enable large-scale hybrid seed production, with field trials demonstrating significant yield heterosis ranging from 31% to 55% compared to national check varieties. In addition to productivity, improving oil and meal quality has been a key objective. By integrating genes from canola-quality mustard lines, breeders have achieved reductions in erucic acid and glucosinolates, enhancing the health profile and industrial applicability of mustard oil. A high-density linkage map developed using an F1 double haploid mapping population has facilitated the marker-assisted backcross breeding of desirable traits, enabling precise transfer of key quality traits. Transgenic approaches, such as antisense RNA technology, have led to the development of high-oleic, low-linoleic mustard lines with improved fatty acid profiles. These advancements reflect a strategic combination of conventional and biotechnological methods, demonstrating a clear pathway for boosting mustard yields while enhancing oil quality. Molecular markers reported for genetic diversity assessment, mapping and tagging genes/QTLs for different qualitative and quantitative traits and their use in marker-assisted selection have been presented. This progress not only addresses current challenges but also sets the stage for future research aimed at further optimizing productivity, oil quality, and resistance to pests and diseases in mustard cultivation.