Genotype-by-environment interaction and stability of sweetpotato genotypes for root dry matter, β-carotene and fresh root yield

Abstract

AbstractThe study was conducted to estimate the magnitude of genotype x environment interactions (G x E) and to select stable and high yielding sweetpotato genotypes for root dry matter content (RDMC), β-carotene content and fresh root yield, and to identify the most discriminating and representative test environments in Ethiopia. The study was conducted across six environments (Halaba, Kokate, Areka, Arbaminch, Hawassa and Dilla) in southern Ethiopia. Twenty four selected genotypes and one check variety (Tula) were evaluated using a 5 × 5 simple lattice design. Stability analysis was conducted using Genotype plus Genotype by Environment Interaction (GGE bi-plot). Environment, genotype and G × E interaction variances were significant (p < 0.001) for the three traits. The magnitude of environment and G x E interaction was 66.8% for fresh root yield, 44.0% for RDMC and 7.6% for β-carotene content. Three genotypes designated as G1, G6 and G20 were identified as having above average RDMC of 31.82, 32.60 and 30.06%, high β-carotene content of 12.48, 14.27 and 13.99 mg 100 g