Genotype x environment interaction of selected common beans (Phaseolus vulgaris L.) on seed iron and zinc concentrations

Abstract

The study was conducted in three sub-ecological locations in Morogoro to assess the effect of environments on seed iron (Fe) and zinc (Zn) concentration. The specific locations were Ndole, Kasanga, and Mlali, each representing distinct environmental conditions. To achieve a comprehensive assessment, 30 bean genotypes were planted using a Completely Randomized Block Design in three replications. Data on seed Fe and Zn concentration among bean genotypes were collected and analyzed using Analysis of Variance (ANOVA). Additionally, a GGE biplot analysis was utilized to evaluate the stability of the bean genotypes in terms of their seed Fe and Zn concentrations across environments. The use of the GGE biplot provided a visual representation of the genotype’s performance and stability, facilitating the identification of the most promising genotypes. The analysis of variance indicated that there was no significant difference (P≤0.05) in seed Fe concentration within each location, but a significant difference was revealed across locations. Seed Zn concentration showed a highly significant difference (P≤0.001) among bean genotypes both within and across locations. The average seed Fe concentration was 165.1 mg/kg in Ndole, 129.9 mg/kg in Kasanga, and 92.4 mg/kg in Mlali. For seed Zn concentration, the averages were 28.0 mg/kg, 26.9 mg/kg, and 32.8 mg/kg for Ndole, Kasanga, and Mlali, respectively. The GGE biplot revealed that the genotypes Maini Ndefu (G2), NUA-695 (G20), NUA-590 (G14), and Selian-10 (G24) exhibited high stability with high seed Fe concentration, while the genotypes Rojo (G3), Selian-10 (G24), TARI-06 (G30), and Uyole-04 (G27) exhibited high stability with high seed Zn concentration. Therefore, the best-performing genotypes identified in this study can be recommended for further research and potential release as enhanced varieties for bean farmers. These genotypes can potentially contribute to enhanced nutritional quality and agricultural productivity in the region.