铅胁迫对西南山梗菜生长及逆境生理指标的影响

Effects of Lead Stress on Growth and Physiology of Lobelia sequinii

【目的】探究铅胁迫对西南山梗菜生长及逆境生理指标的影响。【方法】采用土壤盆栽模拟试验,设置铅处理浓度为0(CK)、300、500、1 000、2 000、3 000、4 000mg/kg,以Pb2+计。【结果】结果表明,铅处理明显抑制了西南山梗菜的生长,其生物量、根重、根长均极显著低于对照。在铅胁迫浓度为1 000mg/kg时,西南山梗菜生物量、株高、根长、根重在各处理中最高,仅次于对照,且此浓度下植物的根系耐性指数最高,说明西南山梗菜在此浓度铅胁迫下,对铅的耐性最大。随铅处理浓度的增加,其叶绿素含量呈现先升高后降低再升高的变化趋势;植物体内SOD、POD、CAT活性总体表现出先升后降的趋势;MDA呈现增加的趋势。【结论】在一定浓度铅胁迫下,西南山梗菜对铅具有较强的耐性,可以考虑将其作为轻度铅污染土壤的植物修复材料。

【Objective】 The objective of the study is to explore the effects of lead stress on growth and physiological performance of Lobelia sequinii.【Method】 A pot experiment was conducted with seven lead（0,300,500,1 000,2 000,3 000 and 4 000 mg（Pb2＋）/kg（soil）） regimes.【Results】 The results showed that growth of L.sequinii was obviously inhibited by lead stress.The biomass,weight and length of root were significantly lower compared with control regime.The biomass,plant height and root length of L.sequinii were the highest under Pb2＋ concentration of 1 000 mg/kg except for the control.Moreover,root tolerance index was the highest implying that L.sequinii had the strongest tolerance to lead in this concentration.Chlorophyll changed with ＂M＂ shape with increasing Pb2＋ concentration.The activities of SOD,POD and CAT increased firstly,then decreased.However,MDA generally increased with increasing Pb2＋ concentration.【Conclusion】 In relative low Pb2＋ concentration stress,L.sequinii exhibited a strong tolerance.Therefore,it may be a soil phyto-remediation material of mild lead pollution.