Genetic variability and inheritance of aluminum toxicity tolerance in oat

Twenty-one oat (Avena saliva L.) genotypes from the Universidade Federal do Rio Grande do Sul breeding program, in Brazil, were evaluated for their re action to aluminum (Al) toxic levels in nutrient solutions. The Al levels t ested were 5, 10, 15, 20 and 30 g kJ(-1). The root regrowth was evaluated a fter 48 hours in presence of Al. Phenotypic variability was observed at 10 g kJ(-1) and upper levels. Two groups were clearly distinguished at 20 g kJ (-1) level, one of tolerant and the other of sensitive genotypes. The genet ic bases of Al tolerance were determined bn P-1, P-2, F-1 and F-2 generatio ns of nine crosses among tolerant x sensitive genotypes. The tolerant respo nse was conditioned by one gene with dominant effect. The wide sense herita bility was intermediate to high, allowing selection of tolerant genotypes i n early generations, followed by progeny test to identify homozygous lines. The results of this study suggest that the hydroponic method is reliable f or screening germplasm to Al toxicity and may be used in the routine of oat breeding programs.