A 8 x 8 half diallel study carried out in six environments over two seasons indicated
that both gca and sea were influenced by environment and observed higher sensitiveness
of non additive gene effects to the environmental changes. The ratio of additive to
total genotype variance revealed the preponderance of additive gene effects for the
inheritance of effective and total length of primary raceme, capsules on primary raceme,
nodes upto primary raceme, 100 seed weight and capsules per spike, while spikes per
plant and seed yield per plant were mainly governed by non-additive gene effects.
Pistillate parent MCP-2 and monoecious male parent RG184 were identified as the
best combiners for seed yield and some other traits. Among mostly male parent RG-299
was good combiner for spikes/plant and RG 125 was good combiner for seed weight
and nodes upto primary raceme (earliness). Crosses involving mostly male parent
could also exhibit high per se and desirable sea effects for seed yield and other traits.
It may be concluded that male parent possessing 50% length of primary raceme covered
with capsules could be utilized for breeding purpose. Seed yield in castor is governed
by multiple path ways, important yield contributing characters at 120 days after sowing
(DAS) were capsules on primary raceme, effective length of primary raceme, nodes
upto primary raceme ar:l 100 seed weight while capsules per spike, spikes per plant
and 100 seed weight were decisive components for seed yield at 240 DAS. These
pathways could be combined together or optimized through selection however,
considering negative relationship between some traits, use of biparental mating is
suggested. To achieve quantum jump in heterosis breeding development of heterotic
pool would be useful.
Keywords: Castor, G x E interaction, gene effects, combining ability, biparental mating, heterotic pool.
Year: 2000
Volume: 60
Issue: 2
Article DOI: NA
Print ISSN: 0019-5200
Online ISSN: 0975-6906
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