Efeito do alumínio em plantas de Pinhão-Manso (Jatropha curcas L.), cultivadas em solução nutritiva

Abstract

High amounts of aluminum (Al3+) limit the development of many plant species, inhibiting the growth of roots. The physic nut (Jatropha curcas L.) has been studied extensively for the production of biodiesel and despite being tolerant to low fertility soils, the roots of physic nuts do not developed in acid soils. This study aimed to evaluate the development and physiological responses of different accessions of physic nuts in varying doses of aluminum. Seedlings obtained from seeds from São Paulo, Minas Gerais and Bahia, were subjected to aluminum stress at concentrations of 0, 3.0, 4.5 and 6.0 mg L-1 in nutritive solution, with the following parameters: fresh matter of shoot (MFPA), fresh matter of root (MFR), dry matter of shoot (MSA), dry matter of root (MSR), initial length of root before submersion in solution (CIR) and growth of root end after submersion in solution (CFR). For variables MFPA, MFR and MSR, the access from Minas Gerais and Bahia presented higher relative mean different from São Paulo provenance at levels of 5% and 1% significance, respectively. The doses of aluminum showed significant differences for the variables MFR and CFR after submersion in solution, and those results are explained by descendants linear equations. Based on these results, it was noticed that the growth of the species is affected by the presence of aluminum, even considering small levels and independently of the provenance. The doses of aluminum affect root growth for all provenances, with doses above 3 mgL-1, the most harmful to plant growth.