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ThesisItem Open Access GENETICS OF SEED COTTON YIELD AND ITS COMPONENT TRAITS IN COTTON (Gos^pium hirsutum L.) 1977(JAU, JUNAGADH, 2015-02) VALU MANU GOVINDBHAI; Dr. M. D. KhanparaThe present investigation was undertaken with a view to generate genetic information on gene effects, heterosis and inbreeding depression for seed cotton yield and its component traits. The experimental materials consisted of twelve generations, namely Pi, P2, Fi, F2, Bi, B2, Bn, B 12, B21, B22, Bis and B2S of four crosses of cotton viz., Deviraj x GBHV-170, G.Cot-10 x MR-786, G.Cot-12 x GTHV-95/145 and 76IH20 X GJHV-460. Experiment was laid-out in Compact Family Block Design with three replications during Kharif 2013 at Cotton Research Station, Junagadh Agricultural University, Junagadh. The observations were recorded on twelve characters on five randomly selected plants in each replication for Pi, P2 and Fi; ten plants for Bi and B2 and twenty plants for each of F2, Bn, B12, B21, B22, Bis and B2S. The analysis of variance between families revealed that the mean square due to crosses were significant for all the characters except boll weight, ginning percentage, seed index and oil content. Among the progenies within each family, the analysis of variance indicated significant differences among the generation means for all the traits studied in all the four crosses. Mean performance of F| hybrids were higher than their respective better parents for days to flowering, days to 50 % boll bursting, number of bolls per plant, seed cotton yield per plant, seed index and oil content in all the four crosses; for number of monopodia per plant in Deviraj x GBHV-170 and G.Cot-12 x GTHV-95/145; for number of sympodia per plant and lint index in G.Cot-10 x MR786 and G.Cot-12 x GTHV-95/145; for boll weight in crosses, Deviraj x GBHV-170, G.Cot-10 X MR-786 and G.Cot-12 x GTHV-95/145 and for ginning percentage in crosses G.Cot-12 x GTHV-95/145 and 76IH20 x GJHV-460. Moderate inbreeding depression was noticed for seed cotton yield and some of its component traits in four crosses of cotton. Mean performance of all the double backcrosses were higher than their respective better parents in cross G.Cot-10 x MR-786 for number of monopodia per plant and oil content; in cross G.Cot-12 x GTHV-95/145 for ginning percentage, lint index and oil content and in cross 76IH20 x GJHV-460 for seed index and lint index. Significance of simple scaling tests and Cavali's joint scaling test indicated that the presence of gene interactions for all the traits in all four crosses. In sixparameter model by weighted least square technique, the components'm' and digenic [j] were found significant for seed index in cross Deviraj x GBHV-170 and'm', [d], [h] and all the digenic ([i], [1] and [1]) were significant for oil content in 76IH20 x GJHV-460 along with non-significant of (2) value at six degrees of freedom in both cases showing the adequacy of digenic six-parameter model in both the traits. The crosses and the traits which were found significant for were subjected to trigenic ten-parameter model. The trigenic ten-parameter model was found to be adequate in cross Deviraj x GBHV-170 for number of monopodia per plant; in cross G.Cot-10 x MR-786 for seed cotton yield per plant, days to 50 % boll bursting, number of bolls per plant, boll weight, seed index, lint index and oil content; in cross G.Cot-12 x GTHV-95/145 for number of monopodia per plant, ginning percentage, seed index and lint index and in cross 76IH20 x GJHV-460 for number of monopodia per plant, seed index and lint index indicating major role of trigenic interaction for the inheritance of above said traits. On the other hand, (3) with two degrees of freedom was significant for remaining traits in different crosses showing the presence of higher order epistasis and/or linkage. All the ten-parameters were significant only for seed cotton yield per plant and number of monopodia per plant in cross G.Cot-12 x GTHV-95/145. The observed and expected estimates for heterosis over mid parent over better parent and inbreeding depression were in close agreement with each other in all the four crosses for all the traits except for plant height in Devirai x GBHV nn ! G.Cot-10 X MR-786 and days to 50 % boll bursting in G.Cot-12 x GTHV both heterosis over mid parent and inbreeding depression; number of mononodl plant m cross G.Cot-10 x MR-786 only for heterosis over mid parent number of bolls per plant and ginning percentage in Devirai x GBHvTvn™ height m G.Cot-12 x GTHV-95/145 and days to flowering in 76IH0,^ only for inbreeding depression. ^^^20 x GJHV-460 Overall from the present study, it could be concluded that seed cotto •plant and its component traits recorded in four cotton P'='^ additive, dominance and digenic and/or irloo ■ • governed by mating could be followed which would facilitate Biparental non-additive gene effects simultaneou s fortity tor genettc improvement in cotton.ThesisItem Open Access GENETICS OF SEED COTTON YIELD AND ITS COMPONENT TRAITS IN COTTON(JAU,JUNAGADH, 2015-02) VALU MANU GOVINDBHAI; M.D. KHANPARAThesisItem Open Access GENETICS OF SEED COTTON YIELD AND ITS COMPONENT TRAITS IN COTTON (Gossypium hirsutum L.)(2015-02) VALU MANU GOVINDBHAI; Khanpara M. D.Key words: Cotton (Gossypium hirsutum L.), Generation mean analysis, Trigenic ten parameter model, Heterosis, Inbreeding depression. The present investigation was undertaken with a view to generate genetic information on gene effects, heterosis and inbreeding depression for seed cotton yield and its component traits. The experimental materials consisted of twelve generations, namely P1, P2, F1, F2, B1, B2, B11, B12, B21, B22, B1s and B2s of four crosses of cotton viz., Deviraj x GBHV-170, G.Cot-10 x MR-786, G.Cot-12 x GTHV-95/145 and 76IH20 x GJHV-460. Experiment was laid-out in Compact Family Block Design with three replications during Kharif 2013 at Cotton Research Station, Junagadh Agricultural University, Junagadh. The observations were recorded on twelve characters on five randomly selected plants in each replication for P1, P2 and F1; ten plants for B1 and B2 and twenty plants for each of F2, B11, B12, B21, B22, B1s and B2s. The analysis of variance between families revealed that the mean square due to crosses were significant for all the characters except boll weight, ginning percentage, seed index and oil content. Among the progenies within each family, the analysis of variance indicated significant differences among the generation means for all the traits studied in all the four crosses. Mean performance of F1 hybrids were higher than their respective better parents for days to flowering, days to 50 % boll bursting, number of bolls per plant, seed cotton yield per plant, seed index and oil content in all the four crosses; for number of monopodia per plant in Deviraj x GBHV-170 and G.Cot-12 x GTHV-95/145; for number of sympodia per plant and lint index in G.Cot-10 x MR- 786 and G.Cot-12 x GTHV-95/145; for boll weight in crosses, Deviraj x GBHV-170, G.Cot-10 x MR-786 and G.Cot-12 x GTHV-95/145 and for ginning percentage in crosses G.Cot-12 x GTHV-95/145 and 76IH20 x GJHV-460. Moderate inbreeding depression was noticed for seed cotton yield and some of its component traits in four crosses of cotton. Mean performance of all the double backcrosses were higher than their respective better parents in cross G.Cot-10 x MR-786 for number of monopodia per plant and oil content; in cross G.Cot-12 x GTHV-95/145 for ginning percentage, lint index and oil content and in cross 76IH20 x GJHV-460 for seed index and lint index. Significance of simple scaling tests and Cavali’s joint scaling test indicated that the presence of gene interactions for all the traits in all four crosses. In sixparameter model by weighted least square technique, the components 'm' and digenic [j] were found significant for seed index in cross Deviraj x GBHV-170 and 'm', [d], [h] and all the digenic ([i], [l] and [l]) were significant for oil content in 76IH20 x GJHV-460 along with non-significant of 2 (2) value at six degrees of freedom in both cases showing the adequacy of digenic six-parameter model in both the traits. The crosses and the traits which were found significant for 2 (2) were subjected to trigenic ten-parameter model. The trigenic ten-parameter model was found to be adequate in cross Deviraj x GBHV-170 for number of monopodia per plant; in cross G.Cot-10 x MR-786 for seed cotton yield per plant, days to 50 % boll bursting, number of bolls per plant, boll weight, seed index, lint index and oil content; in cross G.Cot-12 x GTHV-95/145 for number of monopodia per plant, ginning percentage, seed index and lint index and in cross 76IH20 x GJHV-460 for number of monopodia per plant, seed index and lint index indicating major role of trigenic interaction for the inheritance of above said traits. On the other hand, 2 (3) with two degrees of freedom was significant for remaining traits in different crosses showing the presence of higher order epistasis and/or linkage. All the ten-parameters were significant only for seed cotton yield per plant and number of monopodia per plant in cross G.Cot-12 x GTHV-95/145. The observed and expected estimates for heterosis over mid parent, over better parent and inbreeding depression were in close agreement with each other in all the four crosses for all the traits except for plant height in Deviraj x GBHV-170 and G.Cot-10 x MR-786 and days to 50 % boll bursting in G.Cot-12 x GTHV-95/145 for both heterosis over mid parent and inbreeding depression; number of monopodia per plant in cross G.Cot-10 x MR-786 only for heterosis over mid parent as well as number of bolls per plant and ginning percentage in Deviraj x GBHV-170, plant height in G.Cot-12 x GTHV-95/145 and days to flowering in 76IH20 x GJHV-460 only for inbreeding depression. Overall from the present study, it could be concluded that seed cotton yield per plant and its component traits recorded in four cotton crosses were governed by additive, dominance and digenic and/or trigenic epistasis gene effects. Biparental mating could be followed which would facilitate exploitation of both additive and non-additive gene effects simultaneously for genetic improvement in cotton.