physicochemical

Research Note
J.Res. ANGRAU 39(1&2)48-52, 2011
ASSESSMENT OF VARIABILITY AND CAUSE AND EFFECT RELATIONSHIP IN
INTERSPECIFIC CROSSES OF SORGHUM (Sorghum bicolor (L.) Moench)
C.V.SAMEER KUMAR, CH.SREELAKSHMI and D.SHIVANI
Agricultural Research Station, Tandur,
Acharya NG Ranga Agricultural University, Ranga Reddy dt-501141
In the present study, an attempt was made
to investigate genetic variability and identify the most
responsible yield components for seed yield among
interspecific crosses of sorghum. The findings of the
study would be useful for establishing selection
criteria in sorghum breeding programme for higher
seed yield. This study was conducted at Agricultural
Research Station, Tandur during 2009-10 rabi
season. The experimental material comprised of 29
segregating progenies of two interspecific crosses
in F 4
generation viz., Sorghum bicolor (cs3541) x
Sorghum usumberense (Sb x Su) and Sorghum
bicolor (cs3541) x Sorghum lewisonii (Sb x Sl) which
were sown in randomized block design with 3
replications. The progenies were grown in 2 rows
plot of 5 m length with row to row distance of 45 cm
and the distance within the row was maintained at
15 cm. Recommended agronomic practices were
followed to raise a good crop. Observations were
recorded on the characters, viz., days to 50%
flowering, days to maturity, plant height (cm), panicle
length (cm), test weight(g), seed yield per plant (g)
and fodder yield (t/ha). Data were recorded from
ten randomly selected plants from each segregating
family per replication and the average was taken
for analysis.
Standard statistical procedures were used
for the analysis of variance and genotypic and
phenotypic coefficient of variation. The association
between yield and yield component traits and among
themselves was computed based on genotypic and
phenotypic coefficient of variances and covariances
(Goulden, 1952). Path coefficient analysis was done
to partition the genotypic and phenotypic correlation
coefficient into components of direct and indirect
effects according to the method of Dewey and Lu
(1959). The statistical analysis was done by using
WINDOSTAT package.
Wide range of genetic variability was
observed among the segregating progenies for
different characters (Table 1). The relative
magnitude of PCV percent was higher than the
corresponding GCV percent for all the characters
studied, which indicated that these traits are having
interaction with environment to some extent. The
genotypic and phenotypic coefficient of variation
ranging from 3.51 to 49.01 and 3.44 to 100.31,
respectively, were highest for fodder yield and seed
yield in the cross Sb x Su and lowest for days to
maturity in both the crosses. In general, the genetic
variability was comparatively high for fodder yield
and seed yield in both the crosses whereas for
panicle length and test weight in Sb x Su only. Thus
it offers better scope for the selection of desirable
characters from the present segregating material.
Since the selection capacity of population mostly
depends on the magnitude of heritable variation, the
heritability coupled with genetic advance as
percentage of mean is more desirable. The genetic
advance as percentage of mean ranged from 3.69
to 100.43 and 3.63 to 53.38 in both the crosses,
respectively. High heritability estimates were
recorded for days to maturity, plant height, test
weight and seed yield indicating lesser influence of
environment in both the crosses. Days to 50%
flowering, panicle length and fodder yield exhibited
low heritability values and were highly influenced
by environmental conditions in both the crosses.
These results are in agreement with the earlier
findings of Narkhede et al. (2000).
The studies on correlation will be useful to
know the intensity and direction of association of a
character with yield. In the present study, seed yield
Email: rishith_sree@rediffmail.com
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