Hanson, Jean (PhD)Kelbessa, Ensermu (PhD)Ayalew, Yetneberk2018-07-172023-11-082018-07-172023-11-082002-10http://etd.aau.edu.et/handle/123456789/9026Characterization of forage gemlplasm is an essential prerequisite for use of forage genetic resources. Fifty accessions of TrifoliulIl steudlleri Schweinf. were studied for 14 morphological quantitative characters, 9 morphological qualitative characters and 6 agronomic characters. Spatial distribution of collection sites of accessions was checked using DIY A-GIS. Cluster analysis grouped the accessions into six groups, where the sixth group had only one member, accession number 9452. A scatter plot made from the first and second factors of the factor analysis, which explains 33% of the total variation, and also the isozyme analysis indicated this accession to be an outlier. A high correlation was observed between characters such as days to 50% flowering and 75% maturity, and leaf width and stipule length. Accession number 9452 was found to show a higher value of Mahalanobis distance, showing this accession is distantly related to the others. Taking eight agronomic characters, accessions were grouped into three groups of high, medium and low productivity. The percentage frequency of phenotypic classes of the accessions for the regions and altitude group and respective chi-square values for eight qualitative characters were calculated. The overall diversity index was calculated to be 0.40 ± 0.07. Higher heritability values were observed for most of the quantitative morphological characters except for stem thickness and flower width. Four enzyme systems, Peroxidase, Acid phosphatase, a-Esterase and p-Esterase, were used in the isozyme study, indicating the percentage of polymorphic loci ranges from 64.7 to 47.1. The isozyme clustering was found to match with the morphological clustering. Key words: Characterization, TrifoliulII steudlleri, cluster analysis, factor analysis, isozyme analysis, heritability, polymorphic loci, GISenCharacterizationTrifoliulII steudllericluster analysisfactor analysisisozyme analysisheritabilitypolymorphic lociGISThesis