DEVELOPMENT OF GALL MIDGE RESISTANT HYBRIDS IN RICE (Oryza sativa L.)
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Date
2011
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ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY
Abstract
The present investigation entitled “Development of Gall midge Resistant
Hybrids in Rice (Oryza sativa L.)” was undertaken to identify the effective restorers
and maintainers among the gall midge resistant lines, based on the results parents were
selected and mated in Line x Tester mating design to study the combining ability,
magnitude of heterosis and to assess the stability of experimental hybrids for single
plant yield and yield contributing characters in Telangana region of Andhra Pradesh.
Further, an attempt was made to understand the inheritance pattern of fertility
restoration for four crosses.
Out of 120 lines screened for restorer and maintainer reaction 22 lines exhibited
very high spikelet fertility (>80%), 18 lines exhibited partial fertility (60 to 80%),
35 lines resulted low fertility (10 to 60%) and 45 lines recorded complete sterility/very
low fertility (<10%).From the above results, 13 R lines were identified as male parents
and crossed with five CMS lines in Line x Tester mating design resulting in
65 hybrids. The 18 parents ,65 hybrids and six checks viz., KRH-2, DRRH-2, PA-6201
Jaya, IR-64 and TN1 were evaluated for gall midge resistance, combining ability,
heterosis and stability of the hybrids at three locations viz., Kunaram (Karimnagar
District), Warangal and Kampasagar (Nalgonda District) of Telangana region of
Andhra Pradesh during Kharif, 2009.
The reaction of genotypes towards the gallmidge at three locations is different; the
incidence recorded was more at Warangal, followed by Kampasagar and Kunaram.
This may be due to the different biotypes existing at three locations. The R lines used
are taken from RARS, Jagtial, which may be resistant to gallmidge biotype 3, due to
existence of different biotypes of gallmidge at Warangal as well as at Kampasagar, the
incidence percentage varied. However, some hybrids exhibited resistance reaction at all
the three locations indicating the resistance of hybrids to different biotypes. Among the
gallmidge resistant hybrids based on per se performance, the top five hybrids identified
are, APMS 6A x JGL 11111, APMS 6A x JGL 8292, IR 58025A x JGL 16284, IR
68897A x JGL 16284 and APMS 6A x JGL 13515. Out of five hybrids 4 are of
medium duration and one is of short duration type.
Segregation pattern for spikelet fertility in F2 generation of four crosses were
studied, the results revealed that the F2 populations of all the four crosses viz., APMS 6A x
JGL 11110-2, APMS 6A x JGL 11110-1, APMS 6A x JGL 17211 and APMS 6A x JGL
16284 exhibited a segregating ratio of 15:1 indicating duplicate dominant epistasis.
On the whole based on the overall performance, among the testers APMS 8A and
APMS 6A, among the lines JGL 11110-2, JGL 11110-1, JGL 11111, JGL 8605 and
JGL 8292, among hybrids APMS 8A x JGL11110-1, APMS 8A x JGL 11110-2, APMS
6A X JGL 11110-1, APMS 6A x JGL 11111, APMS 6A x JGL8605 and APMS 6A X
JGL 8292 are found to be the best in the present investigation.
The overall study of sca effects of different traits, in the present investigation
reveals that sca effects of per se performance of the crosses were not closely related.
The crosses with high per se performance need not be the one with high sca effects and
vice versa. The reason ascribed is due to positive interaction between nuclear and
cytoplasmic genes appear to be important that the interaction between nuclear genes
alone. It is evident from the different studies, the predominance of non-additive gene
action over the additive component, which is ideal for exploitation through heterosis
breeding.
Out of 65 hybrids tested for single plant yield, 61 hybrids are categorized under
group (I) i.e. stable over three environments; the other 4 hybrids are included in groups
(II), which were unstable. The 100% of the parents, 94% of the crosses 100% of the
checks exhibited the stability over three environments, for the important character
single plant yield.
Keeping in view of the above facts, by considering all the factors like, per se
performance, sca effect, standard heterosis over PA 6201and KRH-2, average heterosis,
heterobeltiosis, stability, duration, grain type, LB ratio, the most promising hybrids
identified were APMS 8A x JGL 11110-2, APMS 6A x JGL 11111 and APMS 6A x
JGL 8292.
The hybrid APMS 8A x JGL 11110-2 recorded highest single plant yield of 31.22
gm/plant, high sca effect, and significant standard heterosis over check KRH-2 (23.15)
with 136 days duration. This hybrid is stable over locations for grain yield, with
medium slender grain type, with LB ratio of 3.5, but this was showing susceptibility
reaction to gallmidge at Warangal.
The hybrid APMS 6A x JGL 11111 was the most promising gallmidge resistant
hybrid identified. The duration of APMS 6A x JGL 11111 was 126 days, which
recorded the yield of 28.65 gm/plant, significant sca effect, significant standard
heterosis over KRH-2 (15.52). This hybrid was stable over three locations for grain
yield per plant, with medium slender grain type, having LB ratio of 3.19.
Another gallmidge resistant hybrid identified was APMS 6A x JGL 8292 with
128 days duration, 26.32 gm/plant grain yield and significant standard heterosis (5.42)
over check KRH-2. This hybrid is stable over three locations for grain yield, with
medium slender grain type, having LB ratio of 2.89.
Description
Keywords
hybrids, heterosis, yields, planting, rice, grain, developmental stages, animal husbandry, fertilizers, genotypes