Effect of the genetic and environment interaction on yield, Fe and Zn content among locally cultivated common bean (Phaseolus vulgaris L.) germplasm

Eric Nduwarugira^1*Susan Nchimbi-Msolla¹Ksolwa M Paul¹Teshale Assefa²Clare Tekla Mukankusi³Jean Claude Rubyogo⁴

• ¹Sokoine University of Agriculture College of Agriculture, Morogoro, Tanzania
• ²Alliance of Bioversity (ABC) and CIAT Arusha, c/o Selian Agricultural Research Institute, Arusha, Tanzania
• ³Alliance of Bioversity (ABC) and CIAT Uganda, c/o NARO Kawanda Agricultural Research Institute, Kampala, Uganda
• ⁴Alliance of Bioversity International and CIAT Africa Hub, Nairobi, Kenya

Common bean (Phaseolus vulgaris L.) is a key source of dietary protein and micronutrients in low-and middle-income countries. To support nutrition-sensitive breeding, this study evaluated the effects of genotype (G), environment (E), and genotype-by-environment interaction (GEI) on grain yield and micronutrient content using the AMMI model, testing 83 bush and 84 climbing genotypes across three locations and two growing seasons (2024A–2024B) in Burundi. Combined AMMI-analysis revealed highly significant (p < 0.001) effects of genotype and environment on grain yield, iron (Fe), and zinc (Zn), together with significant GEI for most traits, highlighting the influence of both genetic variation and environmental heterogeneity on genotype performance. Significant variation was observed among genotypes for Fe concentration (52.86–76.5 ppm in bush beans; 53.38–59.7 ppm in climbing beans), Zn concentration (≈17–23 ppm), and grain yield (≈950–2240 kg ha⁻¹). Several genotypes outperformed check varieties for Fe and Zn, although enhanced micronutrient levels were not consistently associated with high grain yield. AMMI and GGE biplot analyses identified stable, high-performing genotypes across environments. Stability analyses using IPCA scores and AMMI values distinguished stable genotypes from those with environment-specific adaptation, while GGE biplots highlighted discriminative environments and broadly or specifically adapted genotypes. Broad-sense heritability was high for Fe and Zn (h² = 0.68–0.82) but low for yield (h² ≈ 0.30–0.33). The multi-trait selection index (MTSI) effectively identified genotypes combining good yield and micronutrient density. Overall, these findings support multi-environment, integrated selection for breeding high-yielding, nutrient-rich common beans adapted to diverse agro-ecologies.