三个乡土树种对Cu、Pb胁迫的生理生态响应

Physio-ecological response of three native tree species to cuprum and plumbum stress

选择三种乡土树种樟树、大头茶和红鳞蒲桃,喷洒含有不同浓度的Cu和Pb溶液,同时设置一个没有喷洒重金属的空白实验。设置的浓度梯度Cu为0 mg·L^(-1)、50 mg·L^(-1)、150 mg·L^(-1)、250 mgL^(-1);Pb为0 mg·L^(-1)、10 mg·L^(-1)、20 mg·L^(-1)、30 mg·L^(-1)。培育期结束后测量三个树种的树高;根、茎、叶的生物量和总生物量;以及叶片生物膜的透性和SOD的活性。结果表明(1)随着重金属浓度的增加,三种乡土树种的高生长和生物量的增加都受到了显著的抑制,浓度越高抑制越明显。相较而言红鳞蒲桃长势较好。(2)随着Cu、Pb浓度的升高,植物叶片的质膜透性变强,受到的伤害增大。Cu250 mg·L^(-1)下樟树叶片生物膜受到伤害最大,而在Pb30 mg·L^(-1)下大头茶叶片质膜受到伤害最大。(3)SOD活性在Cu的胁迫下呈现随着浓度的增加,先升高后下降的规律,但大头茶的SOD活性在一直增加。(4)在Pb的胁迫下,SOD的活性随胁迫的浓度的升高一直下降,只有红鳞蒲桃在后期表现出了增长的趋势。

Three native tree species Cinnamomum camphora, Gordonia axillaris and Syzygium hance were selected and sprayed with cuprum （Cu） and plumbum （Pb） solutions of different concentrations to examine their physio-ecological response to Cu and Pb stress. The concentrations for Cu were 0 mg·L^-1, 50 mg·L^-1, 150 mg·L^-1 and 250 mg·L^-1; while the concentrations for Pb were 0 mg·L^-1, 10 mg·L^-1, 20 mg·L^-1 and 30 mg·L^-1. At the end of cultivation period, some parameters including tree height, biomass of roots, stems, and leaves as well as total biomass were measured; besides, biological membrane permeability and SOD activities of leaves were surveyed. The results are as follows. （1） The inhibition of growth of three native tree species becomes much more significant as the concentrations of solutions increase. S. hancei grows the best as compared to other species. （2） The biological membrane permeability of tree leaves is increased with the increasing of solution concentrations, indicating the damage caused by the Cu and Pb becomes more serious with the increasing of solution concentrations. When Cu concentrations is 250mg·L^-1, the leaf membrane of C. carnphora is damaged the most as compared with other tree species, while the leaf membrane of G. axillaris is damaged the most at 30 mg·L^-1 Pb. （3） Under Cu stress, SOD activity of leaves is rised at first then decreased as the concentration increases except for G. axillaris, SOD activity of which is increased with the increasing of Co concentrations. （4） Under Pb stress, as the concentration rises, SOD activity of leaves is declined with the exception of S. hancei, leaf SOD activity of which appears to increase in the end of experiment.