The Journal of Research ANGRAU
Contents of 41(1) 2013 - acharya ng ranga agricultural university
Contents of 41(1) 2013 - acharya ng ranga agricultural university
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GENETIC VARIABILITY, HERITABILITY AND CHARACTER ASSOCIATION STUDIES<br />
Brix per cent registered has considerable<br />
environment influence. However, high heritability and<br />
moderate genetic advance expressed as per cent <strong>of</strong><br />
mean was recorded revealing the major role <strong>of</strong><br />
additive gene action in genetic control <strong>of</strong> this trait.<br />
<strong>The</strong>se results were in accordance with the reports <strong>of</strong><br />
Sankarapandian (2002), Sandeep et al. (2009a) and<br />
Rajappa (2009) for heritability and genetic advance,<br />
but contradicts with the results obtained by<br />
Sankarapandian et al. (1996) and Rajappa (2009) with<br />
respect to GCV and PCV estimates who reported<br />
relatively higher values. Higher heritability and<br />
genetic advance for this trait indicate effectiveness<br />
<strong>of</strong> simple direct selection in improvement<br />
programmes.<br />
Juice yield registered higher PCV and GCV<br />
values with negligible difference between them,<br />
indicating less influence <strong>of</strong> environment on the<br />
expression <strong>of</strong> this trait. This also recorded high broad<br />
sense heritability (98.27%) coupled with high genetic<br />
advance as per cent <strong>of</strong> mean (123.06%) indicating<br />
predominant role <strong>of</strong> additive gene action in the genetic<br />
control <strong>of</strong> this trait. Higher values for this trait was<br />
earlier reported by Rajappa (2009) for PCV and GCV<br />
values and by Sankarapandian et al. (1996),<br />
Sankarapandian (2002), Kachapur and Salimath<br />
(2009) and Rajappa (2009) for heritability and genetic<br />
advance. This trait can be considered as a potential<br />
for improvement by simple selection owing to high<br />
heritability and genetic advance.<br />
Juice extraction per cent exhibited higher<br />
values <strong>of</strong> PCV and GCV with narrow difference<br />
between them, indicating less influence <strong>of</strong><br />
environment on the expression <strong>of</strong> the trait. This is<br />
coupled with high heritability (95.03%) and genetic<br />
advance as per cent <strong>of</strong> mean (43.80%) indicating<br />
predominant role <strong>of</strong> additive gene action. Similar<br />
results with respect to heritability and genetic<br />
advance were reported earlier by Sankarapandian<br />
(2002) and Sandeep et al. (2009a).<br />
Total soluble sugars exhibited moderate<br />
value <strong>of</strong> PCV and low value <strong>of</strong> GCV with negligible<br />
differences between them indicating less influence<br />
<strong>of</strong> environment on the expression <strong>of</strong> this trait. Broad<br />
sense heritability and genetic advance estimates were<br />
also higher. Moderate variability <strong>of</strong> this trait coupled<br />
with high heritability and genetic advance indicate<br />
higher scope for further improvement through simple<br />
selection procedures.<br />
Moderate value <strong>of</strong> PCV and low value <strong>of</strong> GCV<br />
were registered by bioethanol yield coupled with high<br />
broad sense heritability and moderate genetic<br />
advance expressed as per cent <strong>of</strong> mean indicating<br />
major role <strong>of</strong> additive gene action in the genetic<br />
control <strong>of</strong> this trait.<br />
Sugar yield registered higher values <strong>of</strong> PCV<br />
and GCV compared to all other traits under study<br />
with considerable difference between them indicating<br />
substantial environmental influence on the expression<br />
<strong>of</strong> this trait, which is reflected in relatively higher broad<br />
sense heritability (95.16%) and high genetic advance<br />
expressed as per cent <strong>of</strong> mean (123.47%) indicating<br />
major role <strong>of</strong> additive gene action in the genetic<br />
control <strong>of</strong> this trait. Result <strong>of</strong> the present study is in<br />
conformity with the earlier reports <strong>of</strong> Krishnakumar<br />
et al. (2004) and Patel et al. (2006) with respect to<br />
heritability and genetic advance. Though heritability<br />
and genetic advance indicate scope for simple direct<br />
selection to be effective for this trait, actual gain would<br />
entirely depend on its intrinsic association with its<br />
attributing traits.<br />
Correlation Coefficients<br />
<strong>The</strong> correlation co-efficients among the<br />
selected characters related to fresh stalk yield and<br />
sugar yield in F 2<br />
population <strong>of</strong> ‘27 B × SSV 84’ sweet<br />
sorghum cross were estimated; results were<br />
tabulated in Table 2 and 3 and briefly described in<br />
the following paragraphs.<br />
Association <strong>of</strong> fresh stalk yield with its<br />
component characters Fresh stalk yield per plant<br />
was significantly and positively associated with total<br />
biomass per plant, grain yield per plant, plant height,<br />
nodes per plant, stem girth, days to 50% flowering<br />
and days to maturity. Similar trends were evident<br />
from the studies <strong>of</strong> Hapase and Repale (1999), Nahar<br />
et al. (2002), Krishnakumar et al., (2004), Singh and<br />
Khan (2004), Kadian and Mehta (2006), Patel et al.<br />
(2006) and Unche et al. (2008b).<br />
Among the fresh stalk yield attributing<br />
characters, positive and significant association was<br />
noticeable between days to 50% flowering with days<br />
to maturity, plant height, grain yield per plant, nodes<br />
per plant, total biomass per plant and stem girth; plant<br />
height with nodes per plant, total biomass per plant,<br />
stem girth and grain yield per plant; nodes per plant<br />
with total biomass per plant, grain yield per plant and<br />
stem girth; stem girth with total biomass per plant<br />
and grain yield per plant; total biomass per plant with<br />
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