Identification of core set in fodder cowpea(Vigna unguiculata (L.) WALP) germplasm accessions
| dc.contributor.advisor | Gayathri, G | |
| dc.contributor.author | Gayathri ,G | |
| dc.contributor.other | KAU | |
| dc.date.accessioned | 2024-10-04T09:08:43Z | |
| dc.date.available | 2024-10-04T09:08:43Z | |
| dc.date.issued | 2022-01-15 | |
| dc.description.abstract | The study entitled “Identification of core set in fodder cowpea (Vigna unguiculata (L.) Walp) germplasm accessions” was carried out at Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during December 2020-May 2021 with the objective of assessing variability in the fodder cowpea germplasm accessions, constitute a representative core set and to evaluate the representativeness of the core set vis a vis base collection. 143 fodder cowpea (Vigna unguiculata (L.) Walp) genotypes collected from NBPGR, New Delhi and bush type cowpea varieties of KAU along with 3 check varieties formed the base collection. There were 2 experiments, in which experiment 1 was evaluation of seedlings and experiment 2 was field evaluation of fodder cowpea variability and identification of core set. Experiment 1 i.e., seedling evaluation of 146 accessions was carried out in Completely Randomized Design with 2 replications. Various seedling characters such as germination %, shoot length, root length, seedling length, fresh weight per plant, dry weight per plant, vigor index and relative growth index were observed. Oneway ANOVA and Principal Component Analysis were also carried out using GRAPES software of KAU. All the genotypes significantly differ each other in all the character. The biplot was constructed using the first two PC’s, in which genotypes like EC723987, IC39908, IC402125, IC398992, NR/18-105 showed maximum scattering and demonstrated maximum genetic divergence among the accessions. Evaluation of variability was carried out in the field using Augmented Block Design. The seeds were sown at a spacing of 15 cm x 30 cm during January 2021. Every accessions were sown in two rows of ten plants each and the check varieties were replicated in all the 13 blocks. The cultural operations were done according to the recommendation of KAU Package of Practices. The genotypes were evaluated for 20 biometric characters and seven qualitative characters. The genotypes showed significant differences for all the characters except secondary branches per plant and stem girth. Biochemical character such as crude protein and crude fibre content for top genotypes which showed high green fodder yield per plant was estimated and all the treatments significantly differ from each other. Genetic parameter analysis was performed for twenty biometric characters and for all the characters PCV values were higher than GCV values indicating the influence of environment. The phenotypic and genotypic coefficient of variation were maximum for Leaf Area Index (LAI), green fodder yield per plant, stem dry weight per plant, leaf dry weight per plant, seed yield per plant etc. and minimum for days to maturity. Heritability and genetic advance was high for number of leaves per plant, LAI, green fodder yield per plant, stem dry weight per plant, leaf dry weight per plant, plant height, seed yield per plant etc. The correlation studies revealed positive correlation of leaf dry weight, stem dry weight, dry matter yield, LAI with green fodder yield per plant. A negative significant correlation was seen in between stem girth and days of 50% flowering. The path analysis provides information on contribution of traits by partitioning the total correlation into direct and indirect effects. Path analysis of fourteen characters revealed high and positive direct effect of stem dry weight, leaf dry weight, primary branches per plant, days of 50% flowering on green fodder yield. High indirect effect on green fodder yield was observed for many characters. Residual effect obtained was 17.6% which indicates that 82.4% variation in yield was contributed by characters under study. Cluster analysis was done using UPGMA (Unweighted Pair Group Method with Arithmetic Mean) method. The 146 accessions were grouped into 30 clusters. Cluster X with 21 genotypes was the largest followed by cluster XI (20 genotypes), cluster XIV (13 genotypes), cluster I (12 genotypes), cluster VII (10 genotypes), cluster II (8 genotypes), cluster IV (7 genotypes), cluster XII and cluster XXVI1 (6 genotypes each), cluster XVII (5 genotypes), cluster VI, cluster VIII, cluster XIX and cluster XXIX (4 genotypes each), cluster XIII (3 genotypes), cluster IX, cluster XV, cluster XVIII and cluster XXIV (2 genotypes each) and the remaining were solitary clusters. Core analysis was carried out using power core (v.1.0) software. The core set formed comprised of 24 accessions (16 per cent) of the entire collection. A comparison of geographical distribution of accessions in core set and base collection were done. The base collection comprised of accessions from India- 34%, Philippines- 14%, Nigeria, USA, African countries, Europe, Australia etc. The core collection contained accession mostly from India with representation from Philippines, Nigeria, USA, Chad, Hungary. A comparison of frequency distribution of qualitative traits in core and base collection were estimated using chi square test and all the characters showed non significance among each other indicated the true representation of core with respect to qualitative characters. Comparison of statistical parameters viz., mean, range and variance with respect to 20 quantitative traits in both core set and base collection were also done using two tailed t-test for comparing mean and homogeneity test (F test) for comparison of variance. In this case also all the character showed no significant difference between the two population revealed that the core set included as much genetic diversity as possible. Phenotypic diversity among core and base was assessed using Shannon-Weaver diversity index (H‟). All character has obtained higher H‟ value with comparable overall mean of 2.008±0.11 and 2.138±0.12 respectively. Percentage of diversity in core set over base collection was 101.5%. The core set seems to be a good subset of fodder cowpea germplasm accessions which covers most of all existing diversity in base collection and eliminated the duplicates. This can form a great population which can further utilize for various breeding aspects. | |
| dc.identifier.citation | 175436 | |
| dc.identifier.uri | https://krishikosh.egranth.ac.in/handle/1/5810215365 | |
| dc.language.iso | English | |
| dc.pages | 121p | |
| dc.publisher | Department of Plant Breeding and Genetics, College of Agriculture,Vellyani | |
| dc.sub | Genetics and Plant Breeding | |
| dc.theme | The study entitled “Identification of core set in fodder cowpea (Vigna unguiculata (L.) Walp) germplasm accessions” was carried out at Department of Plant Breeding and Genetics, | |
| dc.these.type | M.Sc | |
| dc.title | Identification of core set in fodder cowpea(Vigna unguiculata (L.) WALP) germplasm accessions | |
| dc.type | Thesis |