The study involved the evaluation of aluminum (Al) resistance in different bean genotypes. The G35346-3Q accession of P. coccineus was observed to have a high level of resistance to aluminum. It is characterized by an aggressive vine with great biomass and a low harvest index. In contrast, the Al-sensitive Mesoamerican small red drought-tolerant common bean, SER16, has an upright growth habit, matures in under 70 days, and exhibits excellent remobilization of photosynthate to grain.

A backcross of the F1 hybrid to the recurrent common bean parent was pursued to recover the desirable plant and seed type of P. vulgaris. Ninety-four Recombinant Inbred Lines (RILs) from the F5:6 generation of SER16 × (SER16 × G35346-3Q) were developed by single seed descent.

The study used 102 bean genotypes, including the 94 RILs, both parents, and six checks (four from the Mesoamerican gene pool (G21212) , an elite Andean cultivar, and one P. acutifolius accession (G40159)). Twenty-five seeds from each genotype were surface sterilized, pre-germinated, and grown in either a hydroponic system or a soil cylinder system.

In the context of this study, Al resistance refers to the reaction of the genotype to toxic Al in the hydroponic system, whereas tolerance to Al-toxic acid soil refers to tolerance to high Al saturation in acid soil conditions characterized by low nutrient availability