Division of Botany, Indian Agricultural Research Institute, Delhi-12
A collection of 40 self-compatible types of Brassica campestris var. brown sarson cultivated in the Indo-Gangetic belt, was studied over two seasons for six characters related to fitness; their associations were found out and compared with the reported phenotypic and genetic associations in self-incompatible brown sarson and yellow sarson.
Positive and significant phenotypic correlations were observed between primary branches and each of the other characters studied except days to flower. The relative magnitudes of phenotypic correlations and genotypic correlations indicated the existence of strong inherent relationship between a majority of these characters. The large environmental correlations for secondary branches with primary branches, height with primary branches, and siliquae on main axis with height were found to be possible causes for limiting the simultaneous improvement of these characters.
The persistence of considerable variability in the self-compatible types could be related with the changing agro-ecological conditions under which they are grown, entomophilous nature of the crop and the strong genetic associations between some of the characters.
The behaviour of self-incompatible brown sarson and self-compatible yellow sarson are compared with that of self-compatible brown sarson.
