- Research Grants
|Support type:||Scholarships in Brazil - Master|
|Effective date (Start):||September 01, 2013|
|Effective date (End):||August 31, 2014|
|Field of knowledge:||Agronomical Sciences - Agronomy - Soil Science|
|Principal Investigator:||José Lavres Junior|
|Home Institution:||Centro de Energia Nuclear na Agricultura (CENA). Universidade de São Paulo (USP). Piracicaba , SP, Brazil|
The basis for feeding flocks Brazilian is on the grasses, which currently occupy approximately 180 million hectares, of which 56% belong mainly to the genus Brachiaria. Much of the national herd is in the region of savannas, where all soils, the Oxisols, have high acidity, high aluminum saturation (Al) in the exchange complex, have low cation exchange capacity, low levels of P, Ca and Mg. Among these problems there is the toxicity caused by Al, resulting in reduced productivity of these plants. Objective with this study was to evaluate the tolerance to Al in four forage plants of the genus Brachiaria with respect to morphological, physiological and productive plants. The hypothesis to be verified is that with increasing doses of the element in the nutrient solution, genotypes with higher sensitivity will introduce significant changes in the root system and changes in enzyme activity. The experiment will be carried out in greenhouse with four grasses of the genus Brachiaria grown in nutrient solution. Al doses studied are: 0, 12, 24 and 36 mg L-1, using the design of randomized complete block in a factorial 4 x 4 (four x four doses of Al grasses), with four replications. The evaluation will be conducted in two periods of growth, determining the end of the second period: the total leaf area to dry mass of shoots and roots, root length and surface, the aluminum concentration in plant tissues and lipid peroxidation. For these parameters are selected two varieties (tolerant and sensitive), and evaluated the effects of Al on the structure of the root system (root hairs) by scanning electron microscopy and the antioxidant enzymes (catalase, glutathione reductase, glutathione peroxidase and ascorbate peroxidase). Data will be submitted to analysis of variance and the level of significance of the F test will be carried to regression analysis and mean comparison test, Tukey at 5% level of significance, with the aid of SAS statistical software.