| Popis: |
Crop yields in very acidic soils are often limited by increasing aluminium concentrations in the soil solution. lt is therefore desirable to select plant species and varieties resistant to Al toxicity. For plants like cereals it is useful to identify criteria that make possible early diagnosis of Al resistance with respect to grain yield without waiting for maturity. In this study, we evaluate whether the grain yield of 11 rice cultivars grown on nutrient solution with high Al concentration can be related to plant characteristics at the vegetative stage. We found that neither biomass production nor the mineral concentrations (K, Ca, Mg, P, Al) in shoots and roots of 35-day-old plants can discriminate classes of Al-resistant and Al-sensitive cultivars with respect to grain yield. However we observed that the tillering capacity (total number of tillers per plant) was a remarkable characteristic for early assessment of the effect of Al on grain production, as maximum tillering occurs 35-45 days after planting. This is quite a simple criterion for wide use in plant selection. As an important conclusion, we can assert that, though often done in many previous studies, it is hazardous to assess Al toxicity at the vegetable stage for plant species that are cultivated for grain production. |
