Division of Genetics, Indian Agricultural Research Institute, Delhi-12
*Present address: Plant Introduction Division, I.A.R.I., Delhi-12.
An analysis of genetic divergence as measured by D2 statistic in 55 populations consisting of ten parents and all possible F1 hybrid combinations was attempted.
The analysis of means revealed considerable variation among the parents and hybrids for all the characters studied, namely flowering time, height, height at branching, fruit bearing branches and capsules per plant and excepting seeds per five capsules. Negative heterosis was observed for flowering time, height, height at branching and seeds per five capsules and positive heterosis for the remaining two characters.
Using Mahalanobis's D2 statistic, the 55 populations could be grouped into ten clusters. The analysis has revealed that the diversity amongst the parents is mostly reflected in the corresponding F1’s also. There was considerable diversity amongst the parents which is not necessarily related to their geographical diversity. One of the parents, M. 10, is Wliquely diverse from the rest of the types.
The role of adaptation and the effect of genes for rust resistance in relation to genetic diversity are discussed in the present investigation.
The data have indicated the need for the examination of morc Peninsular types, for these types appear to have higher general combining ability than the Gangetic types and hybrids involving them have essentially the same desirable features as their parents.
