Variability of cassava (Manihot esculenta [Cranz]) genotypes for nutritional composition in Southwestern Ethiopia

The study utilized a total of 100 cassava genotypes sourced from IITA, Nigeria (biofortified genotypes) and locally collected landraces of Ethiopia, conserved at Jimma Agricultural Research Center. So, understanding variability in nutritional composition can guide future genetic improvement and support the development of nutritionally enhanced cassava varieties. The objective of the study was to assess variability of cassava genotypes-based their nutritional compositions analysis. The analysis of variance (ANOVA) revealed highly significant differences among the studied genotypes for all traits. The mean separation analysis revealed largest values of Beta carotene was recorded with genotypes G79 (18.91) and G106 (17.82%) whereas maximum starch content of 77.79 and 77.22% were recorded with genotype G33 and G29respectively. The maximum dry mater content was recorded with G100 (75.93%) and G128 (71.63%). Correlation analyses revealed highly significant and positive associations between organic matter and dry matter contents (0.98***). Ash content positively correlated with beta-carotene (0.28**) but negatively correlated with OM (-0.33***). However, starch positively correlated with OM (0.135) and DMC (0.124) and poor but negative correlated with protein. These association indicated that traits influence one another which might be due to physiological trade-off or the increment of one trait cause to the increment of another trait. PCA further revealed substantial variation among genotypes, where the first three PC with Eigen values > 1 explained 68.00% of the total variation. Dry matter, moisture content and organic matter were major contributors to Dim-1, while protein and nitrogen contributed to Dim-2, whereas tannin showed a slight negative association with dimension 2. Cluster analysis grouped the studied genotypes into six distinct clusters, each characterized by specific trait combinations. Generally, the results of the study provided concrete information for future cassava breeding program in Ethiopia.