The choice of breeding method for the genetic improvement of any crop largely
depends on understanding the genetics and inheritance patterns of the traits
involved. The knowledge pertaining to gene actions and interactions is
likely to direct and strengthen the crop breeding programmes. With this
objective the present investigation aims to elucidate the nature and
magnitude of gene action associated for various earliness and disease trait
through generation mean analysis (GMA) with six generations (P1, P2, F1, F2,
B1 and B2) of two crosses involving three diverse parents of cucumber. The
studies were undertaken at Experimental Research Farm of the Department of
Vegetable Science, Dr YSP and UH&F Nauni, Solan, HP (India) under open field
conditions. Experimental results revealed that non-allelic interactions were
present for all the traits considered in both the crosses as evident from
individual scaling and joint scaling test. In the inheritance of most of
traits except a few, both additive and non-additive gene actions contribute
significantly therefore, the breeding methods reciprocal recurrent
selection/ bi-parental mating could be exploited for the improvements of the
traits. Earliness traits viz., node number bearing first female flower and
days to first fruit set was mainly governed by dominance (h) and hence these
characters can be improved through heterosis breeding. The duplicate type of
epistasis influenced all traits in both cross-combinations; indicating the
mild selection intensity in the earlier generations while intense in later
generations.