Changes of physiological indices of Jatropha curcas to aluminum stress under different temperatures and exogenous calcium

Jatropha curcas seedlings in the solutions culture were used to examine the effects of different concentrations of acid-aluminum(Al³⁺:0,0.01,0.1,1,5 mmol/L)on the following physiological indices,including root vigor,malondialdehyde(MDA),proline(Pro) content and peroxidase(POD)activity of leaves at three temperatures(24,29,34℃).The results indicated that under the same Al³⁺concentration,the seedlings'root vigor decreased,the amount of MDA,Pro and the POD activity in leaves increased as the temperature rose.On the other hand,as the Al³⁺ concentration rose,root vigor trended to decrease,the amount of MDA and Pro and the POD activity trended to increase at each temperature.Mild amount of Al³⁺ stimulated the root vigor,brought down the MDA and Pro content as well as the POD activity at lower temperatures(29℃,Al³⁺:0.01 mmol/L;24℃,Al³⁺:0.01,0.1 mmol/L).However,all seedlings at three temperatures were damaged more or less if the Al³⁺ concentration exceeded 1 mmol/L.Treated the seedlings with 1 mmol/L Al³⁺ at 29℃,the damages decreased with the increase of exogenous calcium.