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Cotton Genomics and Genetics
2
by barbadense parents, the performance of
interspecific hybrids declined. This popularity of
interspecific hybrids declined and the intra hirsutum
hybrids have occupied major area under hybrids. In
India research on
G. barbadense
has been neglected as
compared to other cultivated species. Therefore no
sufficient progress has been achieved in improving
yielding ability of
G. barbadense
cottons. Therefore it
is necessary to give much attention to improve the
yielding ability of the high priced
G. barbadense
cotton looking to its superior fiber quality. Based on
the factors such as changing consumption pattern,
increasing population, competition from synthetic
fibers, India needs to increase cotton production in
various quality groups.
During
Bt
era, though hybrids have occupied over 90
per cent area of cotton cultivated in India, there is a
very clear decline in diversity of cotton in terms of
fiber length classes. There is a steep rise in production
of intra
hirsutum hybrids, while production of extra
long staple and short staple cotton has come down
drastically. The situation of ELS interspecific hybrid
cultivation has worsened in
Bt
era that even though
india boasts of exporting cotton, import of ELS cotton
has become inevitable. The main reason for the
decline in realized potentiality of interspecific hybrids
has been the lack of prioritized research on improving
potentiality of barbadense cotton and developing
hybrid oriented populations based on them and
utilizing them in deriving potential interspeciific
hybrids. Genetic improvement of barbadense varietal
lines for both productivity and fiber quality has been
very limited. The standard Indian
barbadense variety
Suvin, is still regarded as a unique fiber class in
international market, but the productivity of
barbadense varieties like Suvin has reduced so much,
that it is no more remunerative to cultivate. There is
an urgent need to develop strong base material to
serve the cause of developing new variety of
barbadense and this improved barbadense varietal
base, is essential for improving performance of
interspecific hybrids.
Suvin, an ELS variety of
Gossypium barbadense
species
was developed in 1974 by cross breeding Sujatha with
St.Vincent Sea Island seeds. The release of ELS
variety Suvin with a 2.5% span length of 33~40 mm;
fiber strength of 29~33 g/tex and micronaire of 2.9 to
3.9 has been considered as a significant milestone in
Indian cotton improvement. Apart from Suvin only a
few ELS hybrids grown in India like DCH-32,
TCH-213 meet the international ELS specifications.
According to some reports, the share of India’s ELS
production has declined from 32% of world ELS
production in 1992-1993 to 10% in 2007-2008.
The main objective of this study was to identify
suitable barbadense lines for developing heterotic sub
populations against hirsutum testers to release new
lines as an alternative for Suvin variety of barbadense.
1 Results
1.1 Analysis of variance (RBD)
The preliminary RBD analysis was carried out for
fourteen characters under study for 53 barbadense
lines (included Suvin as check). Mean sum of squares
for fourteen characters are presented in Table 1. ‘F’
test indicated highly significant variation among the
brbadense lines for all the 14 characters except
number of bolls per plant. These results are in
confirmity with the studies of Vande and Thombre
(1983), Vaman et al. (1985), Mirkhmedov et al. (1987),
Mehla et al. (1988), Simongulyan and Kim (1990),
Munasov et al. (1990), Tagiev (1991), Virk et al.
(1991), Dever and Gannaway (1992) and Akumurdov
and Chapau (1992). These authors also observed
substantial amount of variability for seed cotton yield
among F
2
, F
4
and F5 generations of different cotton
crosses.
1.2 Mean
per se
performance of barbadense lines
The mean performance of 53 barbadense lines
included Suvin variety as check, are briefly presented
in Table 2.
1.2.1 Seed cotton yield (kg/ha)
The
per se
performance of 53 barbadense lines
Cotton Genomics and Genetics