Characterization and divergence analysis in cassava (Manihot esculenta crantz)accessions at Jima
2003
Amsalu Nebiyu (Jimma Agricultural Research Center, Jimma (Ethiopia))
Thirty-six germplasm accessions of cassava representing IITA gene pool and Ethiopian land races were studied with respect to different qualitative and quantitative characters contributing to characterization at Jima Agricultural Research Center during 2002-2003 cropping season. The minimum descriptor lists of the International Cassava Germplasm Network and International Plant Genetic Resources Institute were adopted in the study. Cluster analysis based on qualitative characters indicated the formation of six clusters. Vegetative (leaf, petiole, stem, branching habit), flowering and storage root characters brought out a wide range of variations. Analysis of variance for quantitative characters indicated significant (p0.05)variations among the accessions for majority of the characters except plant height, number of main stems, stem girth and storage root length. Estimates of phenotypic and genotypic coefficients of variation also showed the presence of inter genotypic variability for majority of the characters. Relatively maximum phenotypic and genotypic coefficients of variation were observed for harvest index, storage root yield per plant, above ground biomass, number of branches and number of nodes in the order of magnitude. Correlation studies between the various quantitative characters highlighted significant associations among characters. Root yield per plant was significantly and positively associated with number of nodes, number of roots, diameter of roots and harvest index. Cluster and distance analyses of quantitative characters based on multivariate analysis pointed out to the existence of six divergent groups. The clustering pattern of germplasm accessions was found not necessarily related to geographical origin and genetic diversity. The maximum distance was observed between clusters V and VI (squared D
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