Indian mustard (Brassica juncea L.) is a major oilseed crop known for its adaptability to diverse agroclimatic conditions in South Asia. However, productivity, oil, and meal quality are often susceptible to white rust disease and the presence of high levels of antinutritional factors. With the aim of reducing both antinutritional factors (erucic acid) in oil and (glucosinolates) meal, along with resistance to white rust, this study used a marker-assisted pyramiding approach to introgress QTLs from Heera and RLC-3 into three elite Indian mustard cultivars: DRMR150-35, NRCHB101, and NRCDR-02. Using trait-specific markers helped foreground selection, while employing SSR markers assisted background selection in respective cross-combinations. In total, 34 pyramided lines (five BC₃F₅ in DRMR150-35/RLC-3, seventeen BC₃F₆ in NRCHB101/Heera, three BC₃F₅ in NRCHB101/RLC-3, and nine BC₃F₆ in NRCDR-02/RLC-3), with >90% recurrent parent genome recovery, attained development. The resulting pyramided lines underwent evaluation for agronomic performance, disease resistance, and oil quality. The study highlights the potential of MAS in breeding programs to accelerate the development of multi-trait superior cultivars, contributing to sustainable mustard production and enhanced oil quality.

Keywords: Indian mustard (B. juncea L.), marker-assisted pyramiding, white rust resistance, oil quality, molecular markers

Key findings: The 34 selected pyramided lines of the Indian mustard (B. juncea L.) exhibited significant resistance to white rust and superior oil quality without any yield penalty. These lines have potential for general cultivation in India.