Characterization of Molecular Markers Linked to White Rust Resistance and Quality Traits QTL in Indian Mustard (Brassica juncea) for Marker-Assisted Selection.

Indian mustard (Brassica juncea) is one of the largest oilseed crop in the world. High amount of erucic acid and glucosinolate in mustard seeds limit utilization for its oil and cake. Therefore, breeding for low glucosinolate, low erucic acid, and white rust resistance are important for crop improvement in Indian mustard. The objective of this study was to validate the molecular markers linked to major gene(s)/QTL controlling white rust resistance and quality traits in seven genotypes including donor and recipients. For glucosinolate trait, five molecular markers GER1, GER5, At5g67, At5g41, and Myb28 were assayed and all these markers were validated in RLC3 and PDZ1 genotypes for low glucosinolates and in PBR357, PBR422 and PBR91 for high glucosinolates. Two markers, At2g36360 and At5g41560, were assayed for white rust resistance and both were validated in RLC3 and EC59725, whereas At2g36360 was validated only in Donskaza and At5g41560 in PDZ1. For erucic acid, two CAPS markers, FAEII and FAEIII, were assayed. For low erucic acid, both markers were validated in RLC3, EC58325, Donskaza, and PDZ1 genotypes, whereas for high erucic acid, both were validated in PBR357, PBR422 and PBR91. Phenotypic data of these genotypes were also estimated for these traits to confirm with results of molecular markers. For the introgression of genomic regions associated with white rust resistance, two set of backcrosses were made using Donskaza as donor and PBR357/PBR422 as recipient parent. Similarly, for low glucosinolates and low erucic acid, RLC3 used as donor and PBR357 and PBR422 as recipient parent. Further research is needed to validate these markers in backcross population and these markers will enhance the breeding for white rust resistance and quality traits in Brassica juncea.