Unveiling morphological diversity of taro (Colocasia esculenta) accessions for breeding and conservation in southwest Ethiopia

Abstract

Taro is an important food and income crop in Ethiopia, particularly in high-rainfall areas of the southern, southwestern, and western regions. Despite its significance, limited information exists on the morphological diversity of locally cultivated accessions, limiting genetic improvement and conservation efforts. This study was conducted to characterize and assess the diversity of taro accessions from southwest Ethiopia. Sixty-four taro accessions were evaluated during the 2022/2023 and 2023/2024 seasons under rainfed conditions using a simple lattice design. Fifteen qualitative and thirteen quantitative traits were recorded. Data from 64 taro accessions collected from diverse sources were analyzed using descriptive statistics, ANOVA, principal component analysis (PCA), and multiple correspondence analysis (MCA) in SAS and R. Cluster analyses were conducted to classify accessions. Highly significant variation (p < 0.001) was detected for all quantitative traits, indicating broad genetic diversity. PCV values ranged from 10.14 (leaf width) to 59.80 (cormel weight), and GCV values ranged from 10.14 (leaf width) to 41.05 (number of suckers). Heritability was highest for cormel weight (86.82 percent) and lowest for leaf width (14.71 percent). PCA revealed that yield per plant, yield per hectare, and cormel weight were major contributors to total variation. Qualitative traits also exhibited substantial diversity, supported by a Shannon–Weaver index of H′ = 0.74. MCA dimensions 1–3 explained 32.54 percent of qualitative variation. Cluster analyses grouped accessions into five qualitative and three quantitative clusters, identifying several superior genotypes. The findings demonstrate considerable morphological diversity among taro accessions in southwest Ethiopia, highlighting the potential use of highly variable traits, particularly yield and cormel-related traits in selection and breeding programs for developing improved taro varieties, as well as for targeted conservation and sustainable production initiatives.