蒙古黄芪根系分泌物的化感自毒效应研究

Study on root exudates of allelopathic autotoxicity of Astragalus membranaceus Bge. var. mongholicus(Bge.) Hsiao

以蒙古黄芪为材料,研究了水培法收集的蒙古黄芪根系分泌物对蒙古黄芪种子萌发和幼苗生长的影响。结果表明:蒙古黄芪根系分泌物对其种子萌发和幼苗生长具有显著抑制作用,与对照相比,根系分泌物提取原液处理的发芽率、发芽势和发芽指数分别降低了43. 6%、34. 0%和59. 6%,根系分泌物提取原液对蒙古黄芪幼苗的化感自毒作用最强。经根系分泌物处理后,蒙古黄芪幼苗的超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性均有所增强,根系分泌物稀释倍数小于0. 6时,保护酶活性随着根系分泌物稀释倍数的减小而降低,提取物原液处理的保护酶活性最低。丙二醛(MDA)含量随根系分泌物浓度的升高而增大。根系分泌物稀释倍数小于0. 6时,蒙古黄芪的化感自毒效应随根系分泌物浓度的升高逐渐增强。

In this paper,we investigated the effects of root exudates of the Astragalus membranaceus Bge.var.mongholicus(Bge.)Hsiao on its seed germination and seedling growth.The results showed that the root exudates of Astragalus mongholicus significantly inhibited the seed germination and seedling growth.Compared with the control the germination rate,germination potential and germination index in the root exudates treatment were reduced by 43.6%,34.0%and 59.6%,respectively.The original extract of root exudates had the strongest allelopathic effect on the seedlings of Astragalus membranaceus.The root exudates enhanced superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT)activities.When the dilution of root exudates was less than 0.6,the protective enzyme activity decreased as the root exudates dilution decreased,and the extract solution had the lowest protective enzyme activity.The content of malondialdehyde(MDA)of seedlings was increased with the increment of extract concentration.When the dilution of root exudates was less than 0.6,the allelopathic autotoxicity effects of Astragalus mongholicus were increased with increased concentration of the root exudates.