Genetic diversity and genetic parameter estimate among yam (Dioscorea cayenensis Lam. complex) landraces from southwest Ethiopia

Yams ( Dioscorea spp. L.) are the fourth most economically important tuber crop next to Irish potatoes, cassava, and sweet potatoes. The study was conducted to estimate the magnitude of genetic variation, association between tuber yield and related traits, and to identify the most influential character(s) involving 20 landraces collections of yams for effective selection and conservation. A significant difference ( p < 0. 05) was observed for 11 out of 15 quantitative traits among landraces. PC1 through PC5 had eigenvalues greater than one and captured 71.09% of total variability. Leaf length, leaf width, petiole length, stem height, stem diameter, tuber length, tuber diameter, tuber fresh weight, and tuber dry weight had strong positive contributions to PC1 (32.29%). Heritability values of high magnitude (> 80%) were observed for leaf lob length, internode length, leaf length, however, moderate heritability was noted for leaf width, number of stems, stem diameter, and petiole length. Also, the number of branches, number of stems per tuber, stem height, leaf lobe length, tuber diameter, tuber length, and number of tubers and stem diameter had positive and significant genotypic correlation with tuber fresh weight. This research offers essential understanding of the intricate connections between yam characteristics, underscoring the effectiveness of selecting landraces through a multi-attribute index in guiding future breeding and cultivation strategies. Therefore, leaf lobe length, leaf length, tuber fresh weight, and tuber dry weight should be given due importance in yam breeding programs.