Abstract:
The current research programme on "Combining ability for shade
tolerance and yield in greengram (Vigna radiata (L.) Wilczek) grown
under coconuts" was carried out at the Department of Plant Breeding
and Genetics, College of Agriculture, Vellayani during 1998-2000. The
objectives were estimation of gene action, combining ability effects of
parents and hybrids and heterosis. The experimental material consisted
of five lines, three testers and their fifteen hybrids.
Analysis of variance revealed significant differences among the
genotypes for all the eleven characters subjected to statistical analysis
except height of plants and shade intensity. The genotypes L3 (MGG.
314), Ls (LGG. 460) and T3 (CO.2» were superior in mean performance
for yield and most of the yield attributes. The hybrids Ls x T 2 (LGG.
460 x Pusa baisakhii and L1 x T3 (IIPRM.3 x CO.2) were superior in
mean performance for yield, pod characters, photosynthetic efficiency
and tolerance to pod bug infestation.
Non-additive gene action predominated for all the nine characters
showing significant differences among the treatments. Ls (LGG. 460)
and T 2 (Pusa baisakhi) were the best general combiners for yield and
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length of pod while L) (IIPRM.3) was the best combiner for crop duration,
pods per plant and photosynthetic efficiency. The hybrid L) x T 3 (IIPRM. 3
x CO.2) was the best specific combiner for yield.
Significant heterosis was observed for all the characters studied.
Ls x T 2 (LGG. 460 x Pusa baisakhi) showed maximum relative heterosis
and heterobeltiosis for yield and pod length whereas L) x T 3 (IIPRM.3 x
CO.2) showed maximum heterosis over mid parent and better parent for
days to 50 per cent flowering, days to final harvest, pods per plant and
photosynthetic efficiency.
Combining the mean performance, sca effects and heterosis, Ls
x T 2 (LGG. 460 x Pusa baisakhi) and L) x T 3 (IIPRM.3 x CO.2) were
identified as superior crosses in terms of yield and yield attributes. The
hybrid L) x T 3 (IIPRM.3 x CO.2) was also superior for days to 50 per
cent flowering, days to final harvest and photosynthetic efficiency.
