Differential response of three bean (Phaseolus vulgaris) cultivars to aluminium

The response of three bean (Phaseolus vulgaris) cultivars to 10 mg 1“1 Al in nutrient solution was studied using tolerance indicies based on root elongation, root dry weight, shoot dry weight and leaf expansion growth. Plant Al and Ca concentrations were determined. According to the tolerance index based on root elongation, the cultivars Hilds Maxi and Seleccion F-15 were Al tolerant, while Eagle was Al sensitive. Aluminium supply significantly affected shoot growth in Seleccion F-l 5 and this cultivar exhibited unusually high Al concentrations in shoots. Eagle, the most Al-sensitive cultivar, was able to restrict Al uptake and transport. In the presence of Al, calcium uptake was significantly decreased in all cultivars. Scoring for tolerance using root elongation as a single criterion may be misleading in genotypes which accumulate high amounts of Al in shoots.