Differential aluminum tolerance of Portuguese rye populations and North European rye cultivars

Aluminum toxicity is the main toxic factor limiting crop production in acid soils. The development of cereal varieties adapted to such conditions is a great challenge for plant breeding. Identification and introduction of Al- tolerant genes into breeding material is one way of solving the problem. Ry e is considered one of the most tolerant species among cereals, although a great intra- and interspecific variability has been found. Al toxicity is u sually expressed by an inhibition of root elongation. Therefore, measuring the root regrowth of plants after exposure to an aluminum solution can give a good indication of a plants behaviour in acid soils. This paper compares the behaviour of Portuguese rye populations and European rye varieties whe n grown at different aluminum concentrations. The results obtained reveal t hat Portuguese rye populations are more tolerant than the European cultivar s, with most of them being even better than the Al-tolerant cv. Dank. Zlote , used as a tester.