?GENOTYPE X ENVIRONMENT INTERACTION IN RELATION TO DIALLEL CROSSES FLOWER CHARACTERS IN BEAN (LABLAB PURPUREUS)

Abstract

Diallel analysis includes combining ability effects and components of genetic variation. They were estimated over two
environments for flower characters from a half-diallel cross by involving six parents. Both general combining ability (gca)
and specific combining ability (sca) were important for all characters with preponderance of additive gene actions. Envi-
ronment had significant effect on all characters except flowers/inflorescence. Best general combiners were DS52, DS106,
DS112 etc. Complete dominance was observed for flowering date in environment-2, flowers/inflorescence in environ-
ment-1 and pods/inflorescence in both environments. Over dominance was found for flowering date in environment-1 and
partial dominance for flowers/inflorescence in environment-2 and for inflorescence/plant in both environments. Characters
were governed by asymmetrical distribution of positive and negative alleles. Dominant and recessive genes were equally
distributed for flowering date and inflorescence/plant whereas unequally distributed for flowers/inflorescence and pods/
inflorescence. One or two gene groups were involved in flower characters of lablab bean.