Abstract

The study aimed to assess the tolerance of Andean genotypes to aluminium (Al) toxicity, a significant constraint in common bean production in Africa and Latin America. Nineteen Andean genotypes, along with the Al-resistant check ALB91, were evaluated for seedling Al tolerance in a hydroponic system within a screen house at the University of Zambia. Root length (RL), root dry weight (RDW), and number of lateral roots (NLR) were measured, and the percentage reductions in RL, RDW, and NLR were calculated as indices for tolerance to Al toxicity. Significant genetic variability for Al toxicity tolerance was observed among the 19 genotypes. The genotype PI527538 exhibited superior Al tolerance, displaying the smallest percentage reduction in RL and NLR compared to the other evaluated genotypes and the check. PI527538, an Andean and yellow-seeded genotype originally from East Africa, holds promise for use by the bean breeding community in developing Al-tolerant varieties across different Andean market classes.

Key words: Aluminium, Andean, common bean, tolerance, toxicity.