Genotypic variation for seed size and related traits in wheat (Triticum aestivum L.)
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Date
2011
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Publisher
CCSHAU
Abstract
The present investigation entitled “Genotypic variation for seed size and related
traits in wheat (Triticum aestivum L.)” was conducted during rabi 2009-2010 under normal
and late sown environments at CCSHAU, Hisar. Ten genotypes (SG22, Raj3765, PBW550,
LOK1, K68, C306, WH283, WH542, HJP62 and HD2009) representing a wide range of
spectrum of variability for their grain size (bold, intermediate and small) were used for the
estimation of grain filling parameters, the main causal components of grain size.
Accumulated growing degree days (GDD) from anthesis was used as the time scale during
the grain development period. Field observations were recorded from five competitive plants
for days to 50% heading, days to anthesis, days to maturity, number of grains per spike, spike
length (cm) and 1000-grain weight (g). Grain development rate (GDR) and grain
development period (GDP) were calculated for each genotype replication wise fitted by non
linear regression to a logistic curve. Significant genotypic differences were present for all the
characters under normal and late sown environments. The relative ranking of the genotypes
for grain development period differed in two environments. This implied that GDP was more
sensitive to the environment. On the other hand GDR was more stable trait and least affected
by the environment and hence more genetically controlled. Highly significant and positive
association was observed between GDR and 1000-grain weight under both the conditions.
This association was stable over the environment and could account for 50% variability for
1000-grain weight. GDR exhibited highly significant negative association with GDP under
normal sown condition whereas direction of association was also negative but non-significant
under late sown condition. The characters such as 1000-grain weight, number of grain per
spike, spike length and days to maturity had higher magnitude of genetic variance as
compared to environmental variance and this was also reflected by higher magnitude of broad
sense heritability for these traits under both conditions. The expected genetic advance (% of
mean) was highest for GDR followed by 1000-grain weight, number of grains per spike and
spike length under both environments ranging (32 – 64%) whereas for GDP a medium
response ranging (17 – 22%) was expected. The results indicated that the grain size may be
genetically manipulated by improving the GDR in the wheat population.
Description
Keywords
Grain, Developmental stages, Genotypes, Wheats, Packaging, Environment, Yields, Genetics, Biological phenomena, Drying