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【目的】探究铅胁迫对两年生中华金叶榆(Ulmus pumila L.cv.jinye)和水蜡(Ligustrum obtusifolium)的生长、光合、生理及耐受积累特征的影响,为中国西部铅污染地区的生态修复进行适生植物的筛选提供参考依据。【方法】通过向土壤添加外源铅(Pb(CH3COO)2·3H2O)的形式进行处理,设置对照组CK(不施加外源铅)和T1,T2,T3等3个处理组(分别施加相当于土壤含铅量为400,800,1200 mg·kg-1的外源铅),考察铅胁迫对这两个树种的生长、光合、生理及耐受积累特征的影响。【结果】中华金叶榆和水蜡的株高、生物量、耐性指数(Ti)、净光合速率(Pn)随土壤含铅量的增加而下降;中华金叶榆和水蜡体内的抗氧化酶活性随土壤含铅量的增大呈现先升高后降低的趋势;中华金叶榆和水蜡幼树根、茎、叶中含铅量随着土壤含铅量的增加而相应增加,且均在T3处理组中达到最大值。【结论】中华金叶榆在含铅量为800 mg·kg-1时仍然具有较高的耐受能力和铅累积转运能力,使之在中国西部土壤表层铅污染严重地区具有较强的应用潜力。然而,水蜡在含铅量为400 mg·kg-1时虽然也具有较高的耐受能力,但其各部分富集铅的能力和向地上部分转移的能力较差,使之相较于中华金叶榆而言应用潜力大大降低。
【Objective】 To investigate the effects of lead stress on the growth, photosynthesis, physiology and tolerance accumulation of two-year-old Ulmus pumila L.cv.jinye and Ligustrum obtusifolium, To provide a reference basis for the screening of suitable plants. 【Method】 CK (no exogenous lead application) and three treatment groups (T1, T2, T3) were set up by adding Pb (CH3COO) 2 · 3H2O to soil. The results showed that Pb stress affected the growth, photosynthesis, physiology and tolerance to accumulation of these two species. 【Result】 The results showed that the plant height, biomass, tolerance index (Ti) and net photosynthetic rate (Pn) of P. euchinensis and C. parapsilosis decreased with the increase of Pb in soil. The activities of antioxidant enzymes The content of lead increased first and then decreased. The content of lead in roots, stems and leaves of P. euchollas and C. parapsilosis increased with the increase of lead content in soil, and all of them were in T3 treatment group Reaches the maximum value. 【Conclusion】 P. eucholiensis still has high tolerance and lead transport capacity at a lead content of 800 mg · kg-1, which makes it possesses strong potential for application in the serious lead pollution in the soil surface of western China. However, water waxes have higher tolerance to lead at 400 mg · kg-1, but their ability to enrich lead and migrate to above-ground parts is poor compared with Chinese golden leaf elm in terms of potential applications greatly reduced.