Genetic differentiation of growth parameters in Brassica species

Fourteen collections from the Brassica species, B.Juncea, B. nap us, B. carinata and B. campestris showed substantial variability for growth parameters including vegetative (VPD) and reproductive phase (RPD) duration. In general, seed yield in all maturity groups was associated with growth parameters, particularly, VPD, RPD and flowering phase duration, for example, high yielders in the early maturity group and 60-75 days of VPD and 38-40 days of RPD. In contrast, those in the late maturity group had more than 100 days of VPD and relatively short, but varying RPD of 25-50 days. In the medium maturity group, high yields were often found to be associated with relatively long RPD. The yields of B. napus and B. carinata could be improved by shortening total crop duration and increasing RPD. Selection for optimal vegetative phase durations in the progeny of inter-specific hybrids could further improve the yields In Brassica