Differences in shoot boron concentrations, leaf symptoms, and yield of Turkish barley cultivars grown on boron-toxic soil in field

Official URL: http://dx.doi.org/10.1081/PLN-120023279

Using 10 barley Turkish cultivars (Hordeum vulgare L.) field experiments were carried out on soils containing normal and very high soluble boron (B) concentration to study genotypic variation in tolerance to B toxicity in soil and the relationships between the shoot or leaf concentrations of B,severity of B-toxicity symptoms and yield. As judged by differences in degree of severity of B-toxicity symptoms on leaves and in reduction of shoot dry weight or grain yield there was a substantial genotypic variation in tolerance to B toxicity in soil. Among the barley cultivars examined Hamidiye and Bulbul were the most sensitive, and Anadolu and Tarm-92 the most tolerant. The differences in tolerance to B toxicity showed a very close relationship to the severity of B-toxicity symptoms, but not at all to shoot or leaf concentrations of B. Despite the distinct differences in sensitivity to B toxicity, B-tolerant, and B-sensitive cultivars had very similar tissue concentrations of B, and even the most B-sensitive cultivar, Hamidiye contained the lowest B concentration in flag leaves. Shoot dry weight of the cultivars at the tillering stage corresponded well to the grain yields. These results suggested that the symptom scoring for B toxicity symptoms and shoot dry weight at early stage of growth can be considered as reliable criteria for screening cultivars for tolerance to B toxicity in soils. In view of the results obtained in the present study one may speculate that internal mechanisms play a decisive role in expression of differential tolerance to B toxicity in field-grown barley cultivars.