Ethnobotany and Evolutionary Origin of Indian Oleiferous Brassicae

The major oleiferous Brassicae grown in India are Brassica juncea and three ecotypes of B. eampestris ssp. oleifera viz. brown sarson, yellow sarson and toria. Their ethnobotany and possible origin introduction in India are discussed. It is suggested that yellow sarson, toria and self-compatible brown sarson(`tora' type)evolved in India. The former two might have been raised by farmers by selecting a mutant of brown sarson and the latter as a hybrid between yellow sarson and self-incompatible brown sarson. Yellow sarson has been established by having a special character combination, viz. yellowish seed-colour and self-compatibility, which might be brought about by its partial autogamous nature. Precise evidences in regard to B. juncea and self-incompatible brown sarson are not available. However, both these types appear to be initially introduced from north-west in prehistoric times and differentiated further. Since both the constituent parents of B. juncea were available in north-west of India, natural hybridization also occurred here leading to the origin of new combinations. This to a large extent is responsible for the present day enormous variability of B. juncea.