不同种植模式下的菌根网络对狼尾草生长与耐碱性的影响OA

Arbuscular mycorrhizal(AM)fungi connect the roots of different plants via common mycorrhizal networks(CMNs),mediating nutrient transfer and resource allocation among plants and influencing plant interactions.Soil salinization threatens the sustainability of grassland ecosystems,but the impact of CMNs on donor plant growth and alkali stress tolerance in alkaline environments remains unclear.In this study,Pennisetum alopecuroides inoculated with AM fungi served as the donor plant.Different transplanting patterns were established using compartmentalized pot experiments:no adjacent receiver plant on the other side of the root barrier mesh(neighborless plants),an adjacent uninoculated P.alopecuroides receiver plant(conspecific planting),and an adjacent uninoculated Plantago asiatica receiver plant(heterospecific planting).This experiment was designed to investigate the role of CMNs under alkali stress on the donor plant P.alopecuroides.The results demonstrate that:1)Under alkali stress,the presence of neighboring plants(particularly conspecific neighbors)significantly increased the mycorrhizal colonization rate and colonization intensity in P.alopecuroides.2)Under alkali stress and AM inoculation,P.alopecuroides in the conspecific neighbor treatment exhibited significantly higher mycorrhizal dependency and soil easily extractable glomalin-related soil protein content compared with both the neighborless and heterospecific neighbor treatments.3)Alkali stress significantly inhibited the growth of P.alopecuroides,but the establishment of CMNs alleviated this effect.4)Under alkali stress,CMNs significantly enhanced the photosynthetic capacity,levels of osmotic adjustment substances,and antioxidant enzyme activities in P.alopecuroides,while reducing malondialdehyde and superoxide anion radical contents.5)A subordinate function analysis indicated that under alkali stress and AM inoculation,the conspecific neighbor treatment conferred the strongest alkali tolerance upon P.alopecuroides.The results of this study demonstrate that AM fungus-driven CMNs can promote the growth of P.alopecuroides and enhance its alkali tolerance by mediating plant-plant interactions.Notably,CMNs formed with conspecific neighbors had the most pronounced beneficial effect on P.alopecuroides.