大狼毒对紫花苜蓿幼苗生理及内源激素含量的影响

Effects of Euphorbia jolkinii on physiology and endogenous hormone content of alfalfa seedlings

为探明大狼毒所含化感物质对牧草产生的影响,促进毒害草型退化草地的补播治理,本研究采用室内控制实验,开展大狼毒对苜蓿幼苗形态、生理及内源激素含量的影响研究,结果表明:大狼毒植株粉碎物的添加导致紫花苜蓿根系活力下降,叶绿素及赤霉素(GA)、玉米素(ZT)、吲哚乙酸(IAA)合成受阻,致使紫花苜蓿幼苗生长受到抑制。根部土壤粉碎物的添加一方面促进了紫花苜蓿叶绿素的合成,提高其根系活力,另一方面又阻碍了GA、ZT、IAA的合成,最终表现为对紫花苜蓿幼苗生长指标(根长和单株鲜重)无显著影响。综上,大狼毒植株含有的化感物质会对紫花苜蓿幼苗激素合成产生强烈的抑制作用,由此影响紫花苜蓿幼苗的生长。

This research explored the effects of allelochemicals in Euphorbia jolkinii on alfalfa(Medicago sativa)seedlings using an indoor controlled experiment with the aim of providing information to support the replanting of improved forage species and restoration of degraded grassland where the poisonous herb has spread.We determined the effects of E.jolkinii on the morphology,physiology and endogenous hormone content of alfalfa seedlings.It was found that the addition of E.jolkinii reduced seedling root activity initially,and then blocked the synthesis of chlorophyll,gibberellic acid(GA),zeatin(ZT)and indoleacetic acid(IAA),with the ultimate effect of significant inhibition of alfalfa seedling growth.The addition of soil from the root zone of E.jolkinii plants promoted the synthesis of chlorophyll and improved the root activity of alfalfa on the one hand,and reduced the synthesis of GA,ZT,and IAA on the other hand,with the overall result was that there was no significant effect on the growth index of alfalfa seedlings in terms of seedling root length and fresh weight in treatments where root-zone soil was added.In summary,the allelochemicals contained in E.jolkinii can strongly inhibit the hormone synthesis of alfalfa seedlings,and thereby inhibit the growth of alfalfa seedlings but some amelioration through inoculation with E.jolkinii root-zone soil is possible.