两种桉树叶挥发物对蚕豆根尖细胞有丝分裂行为的影响

Genotoxic Effects of the Leaf Volatiles of Eucalyptus Globulus and Eucalyptus Grandis on Vicia faba L.Root Tip Cells

桉树挥发物对周围植物具有化感抑制效应,为了探讨其化感作用机制,以蚕豆为实验材料,探究蓝桉和巨桉两种常见桉树叶挥发油及其两种主成分α-蒎烯和桉油精对蚕豆的遗传毒性.结果表明:在两种桉叶挥发油及其主要成分作用下,蚕豆幼根长仅在最低处理梯度时(24和48 h)显著大于对照组(P<0.05),其余处理组均呈现剂量-时间依赖性抑制效应,α-蒎烯与两种桉叶挥发油的作用效应更为相似;桉叶挥发物在一定范围内干扰了蚕豆根尖细胞的有丝分裂过程,表现为细胞出现微核和多种类型的染色体畸变,有丝分裂指数下降,微核率升高,并表现出剂量-时间依赖效应,但微核率低于正常细胞的本底值.整体来看,两种桉叶挥发物的遗传毒性较小,因此两种桉树通过挥发途径的化感作用不是通过干扰有丝分裂而发挥功能的.

Eucalyptus volatile has the allelopathic inhibitory effect on surrounding plants.In order to explore the allelopathy mechanism of Eucalyptus,the genotoxicity of volatile oils from Eucalyptus globules and Eucalyptus grandis and their two common components α-pinene and eucalyptol to broad bean(Vicia faba L.)were studied.The results showed that the root lengths of broad bean in most treatment groups were significantly shorter than those in control except the lowest treated dose group for 24 h and 48 h when exposed to Eucalyptus volatiles.Among them,α-pinene and the two volatile oils of Eucalyptus leaves had similar effects.To some extent,Eucalyptus volatiles interfered with the mitotic process of broad bean root tip cells,showing micronucleus and various chromosome aberrations,the decrease of the mitotic index and the increase of the micronucleus rate increased,which were dose-time dependent effects.But the micronucleus rates were lower than the background value of normal cells.These results suggested that the genotoxicity of Eucalyptus volatiles did not play a significant role in their allelopathy.