Iswara Prasad C M

Combining Ability and Heterosis in Bittergourd - Vellayani Department of Plant Breeding and Genetics, College of Agriculture 2000



The present investigation "Combining ability and heterosis in
bittergourd (Momordica charantia L.)" was conducted in the Department of
Plant Breeding and Genetics, College of Agriculture, Vellayani, involving
seven parents, 21 hybrids without reciprocals and the check variety Preethi
with a view to assess the general and specific combining abilities, the nature
of gene action and to estimate the extent of heterosis for 13 characters in
bittergourd.
Significant differences were noticed among the 29 genotypes for all the
characters studied with respect to the mean performance. Among the parents
MC 17 (P,) and MC 40 (P6) and among the hybrids MC 18 x MC 40 (P2 ~ P6)
had the high mean performance for yield and most of the yield attributes. The
estimates of PCV and GCV for most of the traits were comparatively high
with very high estimates of heritability and genetic advance indicating the
scope of improvement through selection.
The combining ability analys.is revealed that both GCA and SCA
variances were significant for all the characters indicating the involvement of
both additive and non-additive gene action. However, the ratio of additive to
dominance variance was less than unity for most of the characters indicating the
predominance of non-additive gene action and thereby suggesting the
importance of heterosis breeding programme in crop improvement. The parent
MC 40 (P6) and the hybrid MC 18 x MC 40 (P2 x P6) were the best general and
specific combiners respectively for yield and most of the yield related components.

Several )1ybrids possessed significant relative heterosis, heterobeltiosis
and standard heterosis for all the characters except significant standard
heterosis for 100 seed weight. The hybrid MC 18 x MC 40 (P2 x P6) recorded
the maximum positive standard heterosis for yield and most of the yield
attributes. However, the hybrids MC 17 x MC 40 (PI x P6), MC 17 x MC 53
(PI x P7) and MC 18 x MC 53 (P2 x P7) also exhibited good performance with
regard to yield and related characters.



630.28 / ISW/CO
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