GENETICS OF FIBRE CHARACTERS, YIELD AND ITS COMPONENTS IN INTRA AND INTERSPECIFIC HYBRIDS OF ALLO-TETRAPLOID COTTONS (Gossypium Spp. Linn.)
KrishiKosh
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Title |
GENETICS OF FIBRE CHARACTERS, YIELD AND ITS COMPONENTS IN INTRA AND INTERSPECIFIC HYBRIDS OF ALLO-TETRAPLOID COTTONS (Gossypium Spp. Linn.)
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Creator |
ESWARI B KANCHERLA
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Contributor |
BRAHMESWARA RAO, M.V
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Subject |
cotton, crossing over, yields, planting, heterosis, genetics, biological phenomena, sowing, additives, hybrids
Gossypium Spp. Linn |
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Description |
The present investigation on “Genetics of fibre characters, yield and its components in intra and inter specific hybrids of allo-tetraploid cottons (Gossypium spp. Linn.)” was carried out at College Farm, College of Agriculture, Rajendranagar, Hyderabad during kharif, 2007-08 and 2008-09 to study the combining ability and heterosis for quality and yield characters. Further, an attempt was made to trace out best parents and crosses for future breeding programmes and also to know the gene action controlling the traits through generation mean analysis for designing appropriate breeding strategy. In this direction, seven lines and four testers were crossed in L x T design to generate 28 hybrids and evaluated with check NHH 44 to know the combining ability of parents and crosses. Since L x T design does not provide comprehensive picture on gene action governing the traits, the generation mean analysis through joint scaling test was done in four crosses for eleven characters. High PCV and GCV were recorded for number of monopodia per plant and seed cotton yield per plant and moderate estimates were observed for number of bolls per plant, boll weight. High heritability estimates coupled with high genetic advance were observed for number of bolls per plant, boll weight and seed cotton yield per plant. Estimates of components of variance and their ratios (σ2 gca / σ2 sca) indicated the preponderance of non-additive gene action for days to 50 % flowering, number of monopodia per plant, number of sympodia per plant, number of bolls per plant, boll weight and seed cotton yield per plant, whereas additive gene action was observed for the fiber quality traits viz., 2.5 % span length, uniformity ratio, micronaire value and bundle strength. Based on gca effects the lines, CPD 420 and among the testers, HAG 1055 were identified as best general combiners for yield which were also observed to be good combiners for one or other fibre quality characters. The crosses involving the lines L 604, LK 861 and MCU 17 among the testers were identified as best combiners for earliness. Based on sca effects, the intraspecific crosses, Galama x MCU 17 (G.hirsutum x G.hirsutum) and CPD 420 x HAG 1055 (G.hirsutum x G.hirsutum) were identified as best specific combiners for yield. For fiber quality traits, both inter and intra specific cross combinations ie, CPD 420 x HAG 1055 (G.hirsutum x G.hirsutum) and Galama X Suvin (G.hirsutum x G.babadense) exhibited positive sca effects for bundle strength. Correlation studies revealed significant association in desired direction with yield for bollweight and bundle strength under study (except for ginning percentage, uniformity ratio). Bundle strength was noticed as highly significant contributor to the yield. Path matrix revealed that number of bolls, boll weight and 2.5 % span length was found to have maximum direct positive effect on seed cotton yield. Generation mean analysis through joint scaling tests deciphered that simple additive dominance model exhibited lack of good fit for all the traits in four crosses studied, indicating the role of non-allelic interactions. Dominance and epistatic interactions played a major role in the inheritance of yield and fibre quality characters in cotton. It can be categorically stated that reciprocal recurrent selection or diallel selective mating system are the need of the hour to modify the genetic architecture of cotton for attaining higher yields with desirable fibre properties. In the present study, it is concluded that intraspecific cross CPD 420 x HAG 1055 were identified as promising heterotic hybrid for seed cotton yield and boll number. An interspecific cross Galama x Suvin were identified as early maturing along with high bundle strength and seed cotton yield. Hence, reciprocal recurrent selection or diallel mating systems are the breeding strategies for the improvement of yield and fiber quality traits in cotton. |
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Date |
2016-06-09T12:10:05Z
2016-06-09T12:10:05Z 2011 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/67095
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Language |
en
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Relation |
D8866;
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Format |
application/pdf
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Publisher |
ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY
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