土壤真菌差异影响入侵豚草与本地植物生长及互作

Soil fungi differentially affect the growth of and interaction between invasive weed Ambrosin artemisiifolia and native plants

采用温室盆栽实验,研究了本地植物土壤与豚草入侵地土壤中真菌对外来植物豚草和2种本地植物生长及对豚草与本地植物互作的影响。结果表明:在本地植物土壤中,杀真菌剂处理下,豚草单独种植、与本地植物狗尾草混合种植或与紫花苜蓿混合种植时,其生物量分别比未采用杀真菌剂处理高46.7%、39.1%和90.5%,但杀真菌剂对狗尾草及紫花苜蓿的生物量却没有显著影响;在豚草入侵地土壤中,与未采用杀真菌剂的处理相比,杀真菌剂处理使单独种植的豚草的生物量降低了44.3%,同时杀真菌剂也降低了本地植物狗尾草和紫花苜蓿的生物量,但杀真菌剂的施用对与狗尾草或紫花苜蓿混合种植的豚草的生物量却没有显著影响;进一步比较了本地植物土壤和豚草入侵土壤中真菌对植物生长的反馈作用,结果显示,在本地植物土壤中,真菌对豚草生长呈现负反馈,但在豚草入侵地土壤中,真菌对单独种植的豚草表现出正反馈,而且与本地植物土壤比较,土壤真菌对与本地植物混合种植的豚草的负反馈作用明显变小了。本研究结果为深入研究豚草入侵的土壤微生物学机制提供了一定的实验证据。

A greenhouse pot experiment was conducted to investigate the effects of soil fungi in native plants-dominated soil（NS）and Ambrosin artemisiifolia-invaded soil（IS）on the growth of and interaction between invasive weed A.artemisiifolia and native plants.On NS,the biomass of A.artemisiifolia from monoculture A.artemisiifolia,mixed culture A.artemisiifolia and native plant S.viridis,and mixed culture A.artemisiifolia and native plant M.sativa in fungicide treatment was 46.7%,39.1%,and 90.5% higher than that in non-fungicide treatment,respectively,but no significant difference was observed in the biomass of S.viridis and M.sativa between fungicide and non-fungicide treatments.On IS,compared with that in non-fungicide treatment,the biomass of A.artemisiifolia from monoculture A.artemisiifolia in fungicide treatment was decreased by 44.3%.Fungicide application also decreased the biomass of the two native plants in mixed cultures,but the effect was not significant.The feedback of soil fungi in NS and IS on plant growth and competition was further analyzed.In NS,there was a negative feedback of soil fungi on the growth of A.artemisiifolia,no matter in monoculture or in mixed culture;while in IS,the feedback on the growth of monoculture A.artemisiifolia became positive,and the negative feedback on the growth of mixed culture A.artemisiifolia became less.This study supplied some experimental evidences for the further research on the soil microbial mechanism during A.artemisiifolia invasion.