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Cotton Genomics and Genetics
6
straight away be utilized as varieties for producing
ELS cottons. Hence, 53 F
5
barbadense lines were
evaluated for productivity traits and fiber quality traits
and compared with Suvin known to be standard
barbadense variety in international market.
Among 53 barbadense lines (included Suvin variety as
check), thirteen lines recorded higher
per se
performance for seed cotton yield than Suvin. These
lines also recorded high values for other characters
like number of bolls per plant, mean boll weight, seed
index, ginning outturn, lint index, photosynthetic rate
and stomatal conductance. These parents exhibited
good fiber quality traits like, 2.5% S/L, fiber
micronaire value, fiber tenacity and S/L ratio. The
per
se
performance of these potential barbadense lines
showed higher values than suvin for seed cotton yield
and fiber strength.
The potential barbadense line DB 533×DB 534 F5 IPS
18 (Figure 1) showed superiority over Suvin line for
seed cotton yield, mean boll weight, seed index,
ginning outturn, lint index, fiber micronaire value,
fiber strength and S/L ratio and can be used for
developing separate trait based populations with other
barbadense lines for yield components and fiber
quality. Confirmation of their superiority will enable
release of these new lines as an alternative for Suvin
variety of barbadense.
Figure 1 Most productive barbadense line showed superior than
Suvin line
3 Materials and Methods
To create recombinational variability for combining
ability, the elite barbadense lines DB 533 and DB 534
were crossed during 2007-2008. During two seasons
2008-2009 and 2009-2010 these barbadense
crosses
were advanced to F
2
and F
3
generations, respectively.
The F
3
lines were evaluated for productivity and fiber
quality parameters realizing the emphasis laid on
developing ELS (Extra Long Stable) cotton hybrids
out of 171 F
3
lines, only 53 F
3
lines with acceptable
fiber strength were utilized in this study. The crossing
programme was taken up during 2010. The 28 out of
53 F
4
barbadense lines were crossed with four
common hirsutum testers to obtain derived F
1
crosses
seeds. The
barbadense population of F
4
lines was
selfed and material was advanced to F
5
generation
during the same year.
The entire experimental material was planted on a
medium black soil at College of Agriculture, Dharwad
under irrigated condition. All the 53 F
5
(included
Suvin variety as check) lines, four hirsutum
testers
and derived F
1
crosses along with the straight crosses
(Bench Mark Crosses (BMC)) and ruling commercial
checks (MRC 6918
Bt
check and DCH 32 non
Bt
check) were sown during
kharif
2011 in a
Randomized Block Design with two replications and a
spacing of 90 cm between rows and 60 cm between
the plants within a row. Recommended fertilizer doses
were applied and other cultural practices were carried
out at regular interval. Plant protection measures were
taken at appropriate time to control pests and diseases.
To estimate fiber quality parameters, one sample was
taken from pool of kapas derived from all the
replications. Hence, these characters were not
subjected to RBD analysis.
Correlation coefficient of each character (fiber quality
characters) between F
3
and F
5
generation was found
out by calculating the phenotypic correlation
coefficient. Intergeneration correlation coefficient
analysis was done for entire populations of selected F
3
and F
5
progenies for all the fiber quality characters.
Narrow sense heritability estimates were made based
on the regression of F
5
on F
3
using the following
(Cahaner and Hillet, 1980).
Covariance of F
3
F
5
for the character
b (F
5
F
3
) = --------------------------------------------
Variance of F
3
Regression of each character between F
5
and F
3
was
found out by calculating the regression coefficient
taking the same character in both the generations.
Cotton Genomics and Genetics