中文摘要：

通过对不同浓度铅胁迫下的侧柏、油松、栾树、刺槐4种乔木种子进行种子萌发培养试验，研究了土壤铅胁迫对4种乔木种子萌发特征的影响。结果表明，低浓度的铅胁迫对侧柏、油松、刺槐种子的萌发有一定的促进作用，但作用不显著；随着铅浓度的升高，促进作用逐渐转变为抑制作用，且铅浓度越高，抑制作用越大，均达到了显著水平。而铅胁迫始终对栾树种子的萌发有抑制作用。不同树种的种子萌发对高浓度的铅胁迫耐性有所不同，11000mg·kg^-1的铅胁迫已完全抑制了刺槐种子的萌发，栾树和油松种子发芽抑制率则分别在13000、15000mg·kg^-1的铅胁迫下达到100％，而侧柏种子在15000mg·kg^-1的铅胁迫下仍可发芽。综合分析4种树种种子萌发的各项指标，铅胁迫对各树种的活力指数影响最大。综上分析表明，侧柏、油松对铅胁迫抗性较强，而栾树、刺槐对铅胁迫较为敏感。因此油松、侧柏2种乔木树种适合用于铅污染土壤的修复。

英文摘要：

Effects of different concentrations of Pb^2＋ （0-15 000 mg·kg^-1） on seed germination of four tree species （Pinus tabuli f ormis , Platycladus orientalis , Koelreuteria paniculata ,Robinia pseudoacacia ） were investigated. The results showed that low concentration lead stress stimulated the seed germination of P. tabuliformis,P, orientalis and R. pseudoacacia, but the stimulation effect was not significant. With the increase of lead concentration, the promotion effect was gradually changed into the inhibition effect, and the higher the lead concentration, the greater the inhibition effect, then reached a significant level. The seed germination of K. panlculata was inhibited under any lead concentration stress. The seed germination of R. pseudoacacia was completely inhibited under 11 000 mg·kg^-1 lead stress. The seed germination inhibition rate to P. tabuliformis and P. orientalis were sequentially reached 100% under 13 000 mg·kg^-1 and 15 000 mg·kg^-1 lead stress,and the seed of P. orientalis could still germinate under 15 000 mg·kg^-1 lead stress. Comprehensive analysis of the seed germination indexes of four tree species indicated that the effect of lead stress on the seed vigor index was the largest. The foregoing analysis showed that P. orientalis and 19. tabuliformis had strong resistance to lead stress, and K. paniculata and R. pseudoacacia were more sen- sitive to lead stress. So P. orientalis and 19. tabuliformis were suitable for the vegetation restoration on lead contaminated soil.