不同能源柳无性系对土壤镉污染的抗性研究

运为了比较不同能源柳无性系对土壤镉抗性的差异，采用盆栽方法，设置土壤镉含量5个梯度(0、10、20、40、80 mg·kg^-1)，以乡土旱柳为对照，对能柳1、能柳2、能柳E、能柳C的扦插幼苗对土壤镉污染的生理生态反应进行了系统测定，分析了不同无性系的抗性。结果显示，低浓度处理（≤20 mg·kg^-1）促进苗木生长，其中能柳2在10 mg·kg^-1处理下根和单株生物量增幅最大，可达到对照的132.0%和120.0%；随着镉浓度的增加，生长量下降，在最高浓度处理下，能柳C生长量降低最少，根、枝、叶和单株生物量分别为对照的86.1%、85.3%、82.9%、84.9%，旱柳的枝、叶生物量降低最多，为对照（无镉）的43.8%、45.0%，而能柳1的根、单株生物量降低最多，仅为对照的36.1%、44.4%；随着镉浓度的增加，不同能源柳无性系叶片的SOD、POD、CAT活性和根系活力基本呈现先升后降的趋势，其中，CAT活性变化较为平缓；关于SOD活性和根系活力，能柳1、能柳2在20 mg·kg^-1时已显著下降，旱柳在40 mg·kg^-1时显著下降，而能柳E、能柳C在40 mg·kg^-1时才显著下降。采用隶属函数对5个无性系在镉胁迫条件下的生长和酶指标进行综合分析，不同无性系对土壤镉污染的抗性顺序为能柳C>能柳2>能柳1>旱柳>能柳E。不同无性系对镉均有抗性，都可在镉污染区推广种植，栽培中，应根据土壤污染和绿化目标，做出适当选择。

The Tolerance of Different Energy Willow's Clones to Soil Cd Contamination

In this paper，the gradient(0，10，20，40，80 mg·kg^-1)of soil Cd concentrations was established by mixing CdCl₂ with soil，and some ecophysiological responses of five willow clones, Salix 1，Salix 2，Salix E，Salix C and Salix matsudana, to soil Cd contamination were studied by growing their cut seedlings in pots under the nature environment. The results revealed that the seedling growth of all test clones was enhanced under lower soil Cd concentrations (≤20 mg·kg^-1)，and Salix 2 had the strongest response under 10 mg·kg^-1 treatment，with 132.0% and 120.0% of the root and plant growth, respectively, in comparing with the contro1. Then，the growth decreased with increasing soil Cd, and the growth of Salix C decreased the least under the highest Cd concentration, comparing with the control, the root, shoot, leaf and plant growth being 86.1%, 85.3%, 82.9% and 84.9%, respectively. With increasing soil Cd concentration, generally, the activity of SOD, POD, CAT and Root increased first and then declined. However, the CAT activity of every willow clone changed not much under different Cd concentration. For Salix E and Salix C, the activity of SOD and Root first declined significantly under the 40 mg·kg^-1 Cd concentration, but other three clones first declined significantly under lower Cd concentration. Subordinate function analysis suggested that the tolerance of test willow clones to soil Cd contamination was in order of Salix C>Salix 2>Salix 1>Salix matsudana>Salix E. Five willow clones all had some tolerance to Cd pollution and different willow clone could be planted in different Cd polluted soil for different purpose.