Basic HTML Version
Heterosis Studies Performance Intra Hirsutum Hybrids (
G.hirsutum
x
G.hirsutum
) Kapas Yield Its Components
77
over RCH2
Bt
. However, 19 hybrids exhibited
positive non significant heterosis (Table 11), of which
the hybrid RAH 97 x SC 7, RAH 97 x RGR 58 and
RAH 97 x RGR 37 (16.22%), RAH 97 x SC 18
(13.51%) and RAH128 x RGR 37, RAH 97 x SC 14,
RAH 97 x RGR 32, RAH 124 x SC 18 and RAH 124
x SC 7 (10.81) exhibited heterosis of more than 10 per
cent. On the other hand, as many as nine hybrids
exhibited significant positive heterosis over RAHH 95
check. The hybrid RAH 97 x RGR 24 (35.29%)
recorded high heterosis. Mehta et al. (1986), Gupta
and Singh (1987), Katageri and Kadapa (1989),
Krishnadas and Kadambavanasundaram (1997)
reported similar results.
1.3.10 Lint index (g)
Twenty six out of 48 hybrids exhibited positive
heterosis over RAHH 95 check, one hybrid RAH 97 x
RGR 24 (59.47%) recorded high significant positive
heterosis (Table 12) over RAHH 95 check and as
many as seven hybrids recorded more than 15%
heterosis. On the other hand, the hybrids RAH 97 x
RGR 32 (51.32 %), RAH 97 x RGR 58 (50.72%) and
RAH 97 x RGR 37 (48.68%) exhibited positive
significant heterosis over RCH2
Bt
, but the hybrid
RAH 97 x RGR 24 (85.20%) showed high positive
significant heterosis over RCH2
Bt
check. Marani
(1963), Mehta et al. (1986), Gupta and Singh (1987)
and Singh et al. (1988) also reported high heterosis for
this trait.
2 Conclusion
The enhancement of yield or economic product of any
crop species is the ultimate aim of the plant breeder in
the concerned crop improvement programme. The
yield and its attributing characters are polygenic in
nature and as such are complex in their mode of
inheritance. An understanding of the genetic nature
and inheritance of such complex traits and extent of
their association with yield is very much essential to
help and guide the plant breeder in selection
experiments. It also helps in systematic handling of
breeding material to achieve maximum improvement
by adopting highly sophisticated statistical techniques.
The performance of three top hybrids viz., RAH 97 x
SC 18, RAH 146 x RGR 37 and RAH 146 x RGR 58
in respect of kapas yield needs to be verified for their
performance on large scale basis. Two hybrids RAH
97 x SC 18 and RAH 146 x RGR 37 were superior
over standard commercial check hybrid RAHH 95 for
kapas yield per plant, number of sympodia per plant,
number of monopodia per plant, number of bolls per
plant and ginning outturn and the hybrid RAH 146 x
RGR 58 which exceeded best
Bt
check hybrid (RCH2
Bt
) for kapas yield per plant.
3 Materials and Method
The plant materials used in the present study were
obtained by line x tester crossing. According to this
method, RAH 318, RAH 243, RAH 128, RAH 146,
RAH 97 and RAH 124 were crossed as the lines with
SC 14, SC 18, SC 7, SC 68, RGR 32, RGR 24, RGR
58 and RGR 37 as the testers. The six hirsutum lines
representing Robust plant type classes but differing in
efficiency of physiological processes like photosynthesis,
were selected and crossed to a set of eight testers
representing compact types and faster growth rate.
The seeds of the hybrids were supplied by Dr.
S.S.Patil, Senior Cotton Breeder, Agricultural
Research Station, Dharwad Farm, Karnataka, India, in
2008. The experiment comprising of 48 experimental
hybrids along with 3 checks (BUNNY
Bt
, RCH2
Bt
,
RAHH 95) (one repeated two times) was laid out in
Randomized Complete Block Design (RCBD) with
two replications. Each entry was sown in 3 row plots
of 6 m length spaced at 90 cm with recommended
dose of fertilizer and treatment of seeds with
imidochloprid were sown on 10-7-2008, 2~3 seeds
were dibbled per spot in each row and thinning was
attended to retain one healthy plant per hill at 25 days
after sowing. All the recommended package of
practices were followed to rise healthy crop.
Samples containing 20 bolls were hand-harvested
from each plot prior to picking. The days to 50 per
cent flowering recorded by the number of days taken
from the date of sowing to the date when the first
flower opens in 50 per cent of the plants. The number
of monopodia per plant are the number of branches on
main stem which were lateral and axillary in position
with vertical growth in acropetal succession was
counted at maturity stage, avoiding small sprouts, but
the number of sympodia per plant are branches which
are extra-axillary in position and normally horizontal
with zig -zag pattern of fruiting points were taken as
sympodia. The number of such sympodia on main
stem were counted at maturity stage. The boll samples
Cotton Genomics and Genetics