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Title of Thesis  
GENETIC ANALYSIS COMBINING ABILITY AND HETEROTIC STUDIES FOR YIELD, ITS COMPONENTS, AND FIBRE QUALITY TRAITS IN UPLAND COTTON  
Author(s)  
NAQIB ULLAH KHAN MARWAT  
Institute/University/Department Details  
University of Sindh, Jamshoro / PLANT BREEDING AND GENETICS  
Status (Published/ Not Published/ In Press etc)  
Published  
Date of Publishing  
2002  
Subject  
Crop Production  
Number of Pages  
398  
   
Keywords (Extracted from title, table of contents and abstract of thesis)  
Genetic Analysis, Combining ability, Heterotic studies, Gossypium Hirsutum L, CIM-109, CIM-240, CIM-1100, FH-682, BH-36, CRIS-9, F1 and F2 generation, F3 and F4 generation, General Combining Ability, Specific Combining Ability, CLCuV, Fibre Quality  

 

 
Abstract  

This thesis embodies genetic analysis, combining ability, heritability, genetic advance and heterotic effects for different productive and quality traits of complete diallel cross of six cotton (Gossypium hirsutum L.) cultivars viz; CIM-109, CIM-240, CIM-1100, FH-682, BH-36 and CRIS-9 having diverse genetic origin. The detailed studies were based on data for F1 and F2 generations. The single plant selections made in F2 generation were also studied in F3 and F4 generations through plant progeny row method. Hayman's diallel analysis for genetic components of variation and Griffing's approach were employed to study the general combining ability (GCA), specific combining ability (SCA), the nature of gene action and their interactions for exploring possibilities of isolating useful recombination’s for genetic improvement in cotton. The adequacy of Additive-Dominance Model was tested through regression analysis, arrays analysis and "t2". The model was found adequate for 12 traits and partially adequate for 8 traits in F1 generation. In F2, it showed adequacy for 9 and partial adequacy for 11 traits. In F1, the additive (D) and dominance (H1, H2) components were significant for all the traits, except seed cotton yield and oil content for which additive value was non-significant, whereas micronaire value and short fibre index showed non significant values for dominance components (H1, H2). In F2 generation, the additive component (D) was significant for all the traits with the exception of bolls per plant, seed cotton yield and short fibre index. The dominance components (H1, H2) were non significant for all the traits except monopodia for which only H1 value was significant. It indicated that in F1 the additive gene action was somewhat partial, while in F2 the majority of the traits 2 were controlled by additive gene action manifested on account of segregation and recombination in the segregating generation. Further study of average degree of dominance also confirmed additive gene action in F2 as its values ranging from 0.16 to 2.76 were lower than the F1 values ranging from 0.32 to 3.98. The estimates of heritability, in broad and narrow sense, for the traits as well as of individual F2, crosses were moderate to high with appreciable genetic advance indicating possibilities of improvement through selection. Mean squares due to GCA and SCA were highly significant for all the traits in F1 and F2 generations with the exception of SCA for micronaire and short fibre index in F1; GCA for sympodia per plant in F2; and SCA for seeds per boll, uniformity ratio, short fibre index and oil content in F2 generation. In F1 generation, 12 traits were additive in nature and 8 were pre-dominantly controlled by non-additive type of gene action. In F2, 6 traits showed over-dominance, while additive genes were effective in 14 traits. The combining ability analyses also revealed that majority of traits were controlled by partial dominance with additive gene action. Cultivar CIM-11 00 was the best general combiner by having maximum and desirable GCA for more than half of the traits in F1 and F2 generations. In both generations, the hybrids of the parent CIM-1100 i.e. CIM-109 x CIM-11 00; CIM-11 00 x CRIS-9; CIM-1100 x BH-36; CIM-240 x CIM-1100; CIM-1100 x FH-682 and 2 other hybrids CIM-109 x CIM- 240 and FH-682 x BH-36 manifested the highest SCA effects. Heterosis of varying magnitude was found in F1 and F2 generations. Yield and its components showed maximum heterosis, while fibre and oil quality traits showed low to moderate heterosis. This indicates the higher performance of F1 hybrids for life related traits which is normal from physiological point of view. For CLCuV incidence, cultivar CIM-1100 was resistant, while CIM-109, FH-682 and CRIS-9 were tolerant and CIM-240 and B H-36 were susceptible under D.I.Khan, NWFP conditions. The 10 hybrids and reciprocals of CIM-1100 besides being resistant to CLCuV gave high yield with desirable fibre and oil-quality traits at F1 level. However, on segregation in F2, the hybrids showed varying degree of resistance but were high yielders than all the other cross combinations. On the basis of heritability, genetic advance, GCA, SCA, heterosis and CLCuV incidence, the hybrids of CIM-1100 were found promising and single plant selections made in F2 generation also displayed better performance in F3 and F4 generations. The single plant progenies of four promising crosses superseded the standard cultivars (CIM-109 and CIM-446) in yield and fibre quality traits in F3 and F4 generations. The competitive breeding lines of CIM-109 x CIM-1100, CIM-1100 x CIM-109, CIM-240 x CIM-11 00 and CIM-11 00 x I CIM-240 have potential to become candidate variety/ies, with high yield, better fibre quality and CLCuV resistance, for general cultivation in CRBC command area of Dera Ismail Khan, NWFP.

 
   
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Sr.No Chapter Table of Contents
 
ii 180.kbs
173.Kbps
1 1

INTRODUCTION

1
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2 2 REVIEW OF LITERATURE 4
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3 3 MATERIALS AND METHODS 50
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3.1 Field Experiments 53
3.2 Statistical Analysis (ANOVA) 61
3.3 Genetic Mechanism Analysis 62
3.4 Combining Ability Analysis 68
4 4 RESULTS AND DISCUSSION 73
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4.1 Genetic Analysis 74
4.2 Combining Ability Studies 252
4.3 Heterosis and Inbreeding Depression 287
4.4 CLCuV Studies in F1 and F2 Generations 338
4.5 Performance of F2, F3, and F4 Cross Families 344
5 5 SUMMARYSUMMARY, CONCLUSIONS AND RECOMMENDATIONS 350
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6 6 LITERATURE CITED 358
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7 7 APPENDICES 375
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8 8 SYNOPSIS 384
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