土壤镉污染对不同品种杨树生长状况的影响

Effect of Cd Contamination in Soil on Growth of Poplar of Different Varieties

采用室外盆栽方法,以生长于辽宁省的5种不同杨树品种(分别为辽育1号、938—18、盖杨、辽育3号、小胡杨)为研究对象,通过研究不同杨树品种在土壤Cd胁迫条件下速生杨树品种对重金属Cd的反应,为Cd污染土壤的树木修复提供依据,并借以推动我国污染土壤树木修复工作的开展。研究结果表明,每一树种各处理之间的苗高、地径并没有显著差异。938—18、盖杨及小胡杨的生物量无显著差异,辽育系列苗木的生物量明显受镉污染的影响,低浓度的Cd污染刺激了苗木生长,高浓度的Cd污染对苗木造成了一定程度的伤害,抑制了苗木的生长。土壤中的Cd污染没有对938—18与小胡杨插穗生根数量造成影响。土壤中的Cd2+在一定程度上刺激了盖杨及辽育3号的生根数量。

Pot experiment in outdoors was conducted by comparing 5 kinds of poplar （P. liaoyu 1, 938--18, P. ×gai：cianensis, P. liaoyu 3, and＂P, simonii × P. euphratica＂ × P. sp） to search for suitable tree species which can be adopted in the Cd contaminated region. There was no significant difference between treatments for seeding height and basal diameter. Moreover, there was no significant difference between treatments for biomass of 938--18, P. × gai：cianensis, and＂P, simoniiXP, euphratica＂×P, sp. However, biomasses of P. liaoyu 1 and P. liaoyu 3 were affected significantly by Cd. At the Cd contamination level of 150 mg/kg, their biomasses were significantly decreased. At the level of 5 mg/kg, seedling＇s biomasses of P. liaoyu 1 and P. liaoyu 3 were the heaviest, so the lower Cd density may increase seedling＇s biomass and the higher Cd density may repress seedling growth. There was no influence on the amounts of roots of 938 18 and ＂P. simonii× P. euphratica＂× P. sp, but Cd 2＋ in soil may activate rooting of the rest kinds of poplar.