入侵植物与本地植物互作对丛枝菌根真菌AMF侵染率的影响

Effects of invasive plants interacting with native plants on colonization of arbuscular mycorrhizal fungi

外来植物成功入侵与菌根共生体存在着密不可分的关系,丛枝菌根真菌(AMF)侵染率是反映其侵染植物情况的重要指标,影响侵染率的因素很多,但是入侵植物与本地植物互作对AMF侵染率的影响目前还不清楚。因此,本研究以外来入侵植物黄顶菊Flaveria bidentis、豚草Ambrosia artemisiifolia、三叶鬼针草Bidens pilosa和本地植物狗尾草Setaria viridis、黄香草木犀Melilotus officinalis、藜Chenopodium album为研究对象,设置入侵植物单种处理、本地植物单种处理、每种入侵植物分别与本地植物两两混种处理以及每种入侵植物同时与所有本地植物混种处理,观察测定不同处理下入侵植物与本地植物根系丛枝、泡囊、菌丝及总侵染率,比较研究本地植物种类变化对入侵植物和本地植物根系AMF侵染率的影响,以及3种入侵菊科植物对本地植物AMF侵染率的影响规律是否一致。结果表明,与入侵植物单种相比,除豚草与藜、豚草同时与3种本地植物混种两个处理中,豚草根系的AMF菌丝及总侵染率显著增加外,其余所有处理中入侵植物总侵染率均无显著差异;与狗尾草或黄香草木犀单种相比,每种入侵植物同时与所有本地植物混种处理中,本地植物狗尾草和黄香草木犀根系上的AMF菌丝及总侵染率均显著降低,即随本地植物种类数目的增加,对本地植物根系的菌丝及总侵染率存在显著抑制作用,而对入侵植物无显著影响。

The successful invasion of exotic plants is closely related to the mycorrhizal symbiosis.The colonization percentage of arbuscular mycorrhizal fungi(AMF)is an important indicator reflecting the colonization status of AMF on plants.There are many factors affecting the colonization percentage,but the impact of invasive plants interacting with native plants on the AMF colonization percentage is still unclear.In the present study,the invasive plants Flaveria bidentis,Ambrosia artemisiifolia and Bidens pilosa and native plants Setaria viridis,Melilotus officinalis and Chenopodium album were used as research objects to observe the root arbuscule,vesicule,hypha and total colonization percentage of invasive plants and native plants under different treatments.The monoculture treatment of invasive plants,the monoculture treatment of native plants,the mixed cultivation treatment of alternative invasive plant and alternative native plant and the mixed cultivation treatment of alternative invasive plant and multiple native plants are designed.The effects of alternative cultivation of native plant species on the AMF colonization percentage of invasive plants and native plant roots,and the effects of three invasive Compositae plants on the AMF colonization percentage of native plants are compared.The results showed that as compared with the monoculture treatment of invasive plants,the hypha and the total colonization percentage of Ambrosia artemisiifolia increased in mixed cultivation of Ambrosia artemisiifolia and Chenopodium album and in that of Ambrosia artemisiifolia and three native plants.There was no significant difference in total root infestation percentage of invasive plants in other cultivation treatments.As compared with the monoculture treatment of Setaria viridis and Melilotus officinalis,the AMF hyphae and total invasion rate of native plant Setaria viridis and Melilotus officinalis significantly reduced in the mixed cultivation treatment of alternative invasive plant and all experimental native plants.The hyphae and total colonization percentage of native plants were significantly inhibited with the increase of diversity of native plant species,but those of invasive plants were not influenced.