Effect of N-NH4+/N-NO3- ratios in Al-tolerance of two wheat cultivars under nutrient solutions

Felipe Gallardo A., Mario Pino B., Marysol Alvear Z. y Fernando Borie B.1

Al toxicity is considered as one of the most harmful factors in the growth and development of plants cultivated in soils with increased acidity. Between the options for overcoming such Iimitation it is possible to visualize soilliming, the rationalization of the type of fertilizers employed and the use of AI-tolerant plants.
The response oftwo wheat (Triticum aestivum L.) cultivars (Pitufo BAER and Antilhue INIA) growing 26 days in nutrient solution at four levels of Al (0; 50; 300 and 900 μM) and three NH4+/NO3-mM ratios 0,3113,71 (N1), 0,54/0,54 (N2) and 3,7110,31 (N3) were evaluated at two pH levels (4,8 and 6,0).
The response of the same cultivars was also evaluated by using two Al levels (0 and 100 μM) and N1 and N2 ratios with daily pH correction. Antilhue INIA it was considered more Al sensitive wheat cultivar than Pitufo BAER. Aluminum affected the groth of root lenght in both wheat cultivars especially when nutrient solution had the highest NH4+/NO3- ratio.

Keywords: NH4+/NOa - ratio, Al tolerance, wheat, Triticum aestivum L., nutrient solution.
1 Departamento de Ciencias Químicas, Universidad de La Frontera, Casilla 54-D, Temuco, Chile.