Genetic analysis for yield and its components in early generation and assessment of molecular diversity in soybean (Glycine max (L) Merrill)
KrishiKosh
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Title |
Genetic analysis for yield and its components in early generation and assessment of molecular diversity in soybean (Glycine max (L) Merrill)
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Creator |
Nagma Kousar
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Contributor |
Singh, Kamendra
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Subject |
genetic analysis, yield components, molecular diversity, genetic diversity, soyabeans, glycine max, heterosis, line x tester analysis
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Description |
Thesis-PhD
The present investigation was taken up to make use of line x tester analysis in predicting prepotency of the parents to identify the promising cross combinations and better transgressive segregants in soybean based on heterosis, GCA and SCA effects for seed yield and its contributing characters, character association and their direct and indirect effects on yield, construction of selection index to get the better character combination for effective selection for the improvement of crop plant and molecular marker diversity analysis using twenty different SSR primers. For field experiment thirty two genotypes of soybean comprising of 21 crosses, 7 lines, 3 testers and 1 check were evaluated in F2 and F3 generation using randomized complete block design with two replications during kharif, 2012 and 2013 at Norman E. Borlaug Crop Research Centre, G. B. Pant University of Agriculture and Technology, Pantnagar. The Analysis of variance was found significant for all the characters undertaken. Estimates of variances due to specific combining ability (σ2 SCA) were higher than the GCA variance for most of the characters except plant height, number of primary branches per plant and seed yield in F2, which indicated that most of the characters exhibited preponderance of non-additive gene action and in F3, all the characters showed non additive gene action.. An efficient way for utilizing the non-additive genetic variability in this crop may be through the exploitation of heterosis to get potential transgressive segregants. The estimate of GCA effect of parental lines for different characters revealed that none of the parental lines was excellent in GCA effects for all the characters studied in F2 and F3 generations. This suggested use of multiple parent participation through multiple crossing to effect substantial improvement in yield and its components. The GCA effects in F2 indicated parental lines, Bhatt, DS74 and DT21 to be the best general combiners and among testers, JS335 emerged as a good general combiner. In F3, line CM60 exhibited as the best general combiner and among testers, PS1347 was a good general combiner. On the basis of the GCA effects of the parents in specific crosses, 19.08% of crosses were of ‘A/A’, 53.28% of crosses were of ‘A/P’ or ‘P/A’ and 28.57% were of ‘P/P’ parental combination in F2. However, in F3, 9.52% were of ‘G/G’, 9.52% were of ‘G/A’ or ‘A/G’, 33.33% were of ‘G/P’ or ‘P/G’, 19.05% of crosses were of ‘A/P’ or ‘P/A’ and 28.57% were of ‘P/P’ type of parental combination for seed yield. Out of 21 crosses, DT21 X PS1225, Doko x JS335 and PK1029 X JS335 showed highest positive sca effects for seed yield per palnt in F2, whereas, four crosses, Doko X JS335, DT21 X PS1225, PK1029 X PS1347 and PS1042 X JS335 exhibited significant positive sca effects for seed yield in F3. The nature and magnitude of heterosis revealed that high heterosis for seed yield was mostly accompanied by heterosis for major yield contributing traits. Three F2 crosses, PK1029 x JS335, PK1029 x PS1225 and PS1042 x PS1225 showed significant positive better parent residual heterosis and only one F2 cross, PK1029XJS335, showed significant positive residual heterosis over mid parent, better parent and standard parent for seed yield per plant. Among 21 F3 crosses, thirteen crosses showed significant positive residual heterosis over mid parent, seven crosses over better parent and none of the crosses exhibited significant positive residual heterosis over standard parent. The overall mean values of different characters along with the mean residual heterosis percentage in F2, all the characters except days to 50% flowering, days to maturity showed positive residual heterosis, whereas, in F3, negative residual heterosis was revealed by number of primary branches per plant and dry matter weight. The highest frequency of positive transgressive segregants for seed yield per plant was recorded in crosses, PS1042 X PS1347, PS1042 X PS1225 (80.5%), PK1029 X PS1225 (76%), CM60 X PS1225 whereas, in F3 crosses, CM60 X PS1225(73.3%), DT21 X PS1347(65.5%), Doko X PS1225(55.2%) and PK1029 X PS1347(54.5%) showed high frequency of positive transgressive segregants for seed yield. Harvest index was the most positive direct contributor towards plot yield followed by dry matter weight, number of pods per plant. These characters also exhibited significant and positive correlation with seed yield per plant. Most of the crosses showed high RES value for number of primary branches (X2) or in combination with number of primary branches per plant i.e. (X1+X2). Crosses, Bhatt x PS1347, DS74 x PS1347, Doko x JS335, DT 21 x PS1347, PK1029x JS335 and PS1042 x JS335 showed relatively comparable rate of increase in RES in all possible character combination. Crosses like DS74 x JS335 and DT 21 x PS1225 exhibited highest rate of RES when (X1 + X2, X1 + X2 + X4) and (X1 + X2 + X3 + X4), character combinations could be considered. The assessing of SSR diversity of ten soybean genotype reveled that the Jaccard’s similarity coefficient estimates between pair of different genotypes varied from 0.14 [between JS335 and DT 21] to 0.67 [between DS74 and PS1225] and [between PS1225 and CM60]. The average number of alleles per primer was1.85, while percentage of all bands showed that polymorphism was 100%. The UPGMA (unweighted pair group method with arithmetic mean) dendogram constructed using Jaccard’s similarity coefficient of SSR marker data divided 10 soybean genotypes into three main groups and further sub- divided into five clusters. Cluster IV consisted of maximum number of genotypes indicating maximum genetic similarity among these genotypes. |
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Date |
2016-06-10T15:46:57Z
2016-06-10T15:46:57Z 2014-08 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/67181
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Language |
en
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Format |
application/pdf
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Publisher |
G.B. Pant University of Agriculture & Technology, Pantnagar - 263145 (Uttarakhand)
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