Brassica juncea (Indian mustard) is the most important oil seed crop of northern India. It is cultivated on ca. 6 million ha and contributes approximately 5.8 million tons to the oilseed pool of India. The productivity of mustard in India is low with an average yield about 1 ton/ha. Intervarietal crosses show 30-60% heterosis for yield. Hence, development and deployment of hybrids could lead to increased production and productivity. The crop is ideally suited for hybrid production as it is amenable to cross pollination by honeybees. However, the development of hybrid cultivar has not been feasible until recently due to lack of suitable genetic stocks for commercial hybrid seed production.