Evaluation of Exotic Germplasm of Indian Mustard (Brassica juncea) for Economic Traits

Genetic diversity in Brassica crop is limited as compared to the variability within the species and its relatives including exotic germplasm. The exotic germplasm lines have been found to be reservoir of genetic diversity, especially to several agro-morphological traits and disease resistance which causes severe yield losses in the country. Therefore, one hundred exotic accessions of Indian mustard were evaluated for various agro-morphological, quality traits and disease resistance against two major diseases of this crop, i.e., Alternaria blight (Alternaria brassicae) and white rust (Albugo candida). Among the traits studied, the highest variability was observed for secondary branches per plant (CV 47.3%) followed by siliqua beak length (CV 43.6%) while the least variability was observed for oil content (CV 4.3%) followed by protein content (CV 6%). All the exotic accessions were small seeded. More than sixty percent of total accessions were late maturing. The accession EC511435 was identified as a useful donor for early flowering, more secondary branches per plant and high seed yield per plant as compared to best check. However, EC 511407 and EC511435 were identified as donors for high oil content and high seed yield. Seed yield was positively and significantly correlated with main shoot length, siliquae on main shoot, plant height and oil content. Seven aaccessions showed tolerance to Alternaria blight (percent disease severity or PDS < 10), while eleven accessions to white rust (PDS < 1). However, four accessions namely, EC 511504, EC 511507, EC 511472 and EC511513 showed combined tolerance to both the diseases.