Five wheat cultivars, one triticale and one rye cultivar were studied in aerated nutrient solution with one tenth of the salt concentration of a complete nutrient solution, pH = 4.0 with five levels of aluminum (0, 1, 3, 6 and 10 mg/l) combined with five levels of phosphorus (0; 3.1; 6.2; 12.4 and 31 mg/l). As controls, it was used a complete nutrient solution and distilled water. The aluminum tolerance was evaluated by measuring the primary root lenght of the seedlings after a 12-days growth period in the different treatment solutions. The rye cultivar (Branco) and the triticale cultivar (TCEP 77138) were the most tolerant as far as aluminum toxicity is concerned, independently of the phosphorus concentrations into the solutions. The wheat cultivars: BH-1146, IAC-5, IAC-21 and IAC-24 exhibited Al tolerance in a lower degree when compared with rye and the triticale cultivar. Anahuac showed high sensitivity to aluminum toxicity. The wheat cultivars IAC-5 and IAC-21 were efficient in P utilization; IAC-24 was moderately efficient and Anahuac was considered an inefficient cultivar, taking into account the P efficiency ratio (PER) calculated as mg of top dry weight yield per mg of P in the top tissue when nutrient solutions containing low levels of P (3.1 mg/l) in the absence of Al3+ were used. Considering the nutrient solutions containing 3.1 mg/l of P combined with 3 mg/l of Al3+ the cultivar IAC-5 was considered efficient in P utilization; 'IAC-21' and 'IAC-24', moderately efficient and 'Anahuac', inefficient.
wheat; triticale; rye; cultivars; aluminum tolerance; phosphorus efficiency; phosphorus efficiency ratio; root lenght; top dry weight; nutrient solution