铅对蚕豆种子萌发及根生长的影响

目的]研究铅对蚕豆种子萌发、根生长以及细胞分裂的影响。方法]用不同浓度的PbC l2溶液培养蚕豆种子,以蒸馏水培养作为对照,统计蚕豆种子萌发率,测量根长,根尖固定、染色、压片后镜检,计算有丝分裂指数。结果]1.0×10-45.0×10-4mol/L Pb2＋处理第1、2天,蚕豆种子萌发率稍高于对照,培养第3、4天则与对照相当,Pb2＋对蚕豆种子的萌发没有显著影响。Pb2＋对蚕豆根尖生长产生抑制作用,随着浓度增加,根的生长速率递减,随着处理时间延长,每单位时间的根生长速度递减或停止。根尖细胞有丝分裂指数随Pb2＋浓度的增高和处理时间的延长而递减。结论]Pb2＋对蚕豆根尖生长发育有影响,其影响程度与Pb2＋处理浓度、处理时间有关。

Effects of Pb2+ on the Germination and Root Growth of Vicia faba L.

Objective]The aim was to study the effects of Pb2+ on the seed germination,root length,and mitotic of Vicia faba L..Method] With the distilled water treatment as the control,Vicia faba L.seeds were cultured with PbCl2 solutions at different concentration,and then their germination rate and root lengths were measured,and their root tips were fixed,dyed and squashed for microscopic examination,and the mitotic index(%) of root tip cells was calculated.Result]When seeds were treated with 1×10-4-5×10-4 mol/L Pb2+ for 1 and 2 days,the germination percentage of seeds lightly increased.But 3 and 4 days later,there was no difference between the seeds treated by Pb2+ and the control.Pb2+ had no significant influence on seed germination.Pb2+ inhibited root growth of Vicia faba L..The rate of root growth decreased successively with the increasing Pb2+ concentration.The speed of the root growth per time unit also decreased successively or stopped with the increasing treatment duration.The mitotic index decreased progressively with both the increasing Pb2+ concentration and treatment duration.Conclusion]Pb2+ showed effects on the root growth of Vicia faba L.in a dose-and time-dependent manner.