Identification of Ethiopian Yam (<i>Dioscorea</i> spp.) Collections and Their Phenotypic Diversity Study

Abstract

Yam plant has a major role in Ethiopia particularly in densely populated areas of south, southwestern, and western parts of the country. It grows in a wide range of soils with an altitude range of 1140 to 2200 masl. This study was done to identify yam species collected from major producing areas of the country. The total of sixty yam accessions from ten different geographic origins of South and Oromiya region of Ethiopia were used. The collected samples were planted in complete randomized block design at two research sites of South Agricultural Research Institute. Forty-five qualitative morphological characterizations were used to characterize and identify Dioscorea species. Among these qualitative characters observed in the study presence and absence of spines on stems and roots, number of male and female inflorescence, stem length, twining direction, and flesh color were the major traits considered for species identification. The organoleptic properties evaluation was carried out using fifteen selected local farmers. Statistical analysis was done using Numerical Taxonomy and Multivariate Analysis System Version 2.02 NTSYpc software program and the data reduction function of SPSS for windows. Based on this study, sixty yam germplams of ten major growing areas of the country were identified into six Dioscorea species. These identified Dioscorea species were again subjected to qualitative morphological characterization and 33 morphological traits revealed variability. This implies presence of high diversity in yam (Dioscorea species) of Ethiopia. Most of the morphological variations among the yam genotypes were contributed by young petiole color, tendency of tuber to branch, and tuber flesh color. Hence, these morphological traits could be taken as useful traits for identification of yam cultivars.