虎尾草伴生和丛枝菌根真菌对碱胁迫下羊草生长的影响OA北大核心CSTPCD

Leymus chinensis and Chloris virgata are common plants that are able to tolerate the barren,saline-alkali soils of the Songnen grassland.This research investigated the effects of C.virgata and arbuscular mycorrhizal(AM)fungi on the alkali tolerance of L.chinensis.A pot experiment was conducted with L.chinensis as the host plant,C.virgata as the companion species,and AM fungal communities derived from the rhizosphere of L.chinensis from Songnen saline-alkali grassland as the inoculant.The experiment therefore had three variables:AM fungi,a companion plant,and alkali stress.The mycorrhizal infection rate,growth index,leaf chlorophyll content,malondialdehyde(MDA)content,antioxidant enzyme activity,and osmoregulatory substance content of L.chinensis were measured to analyze the effects of the companion plant and AM fungal inoculation on the physiology and growth of L.chinensis under alkali stress.The main results were as follows:1)The AM fungi effectively colonized the roots of L.chinensis under alkali stress,and C.virgata inhibited this symbiosis.2)Compared with uninoculated L.chinensis,plants of L.chinensis inoculated with AM fungi showed a significantly reduced MDA content,and increased biomass,chlorophyll content,antioxidant enzyme activities,and osmoregulatory substance contents,which resulted in enhanced alkali tolerance.3)The biomass of L.chinensis was lower in the control than in the treatment groups.Compared with L.chinensis in the control group,L.chinensis in the alkali treatment group showed higher contents of osmoregulatory substances,increased enzyme activities,and improved growth.4)The interaction between C.virgata and AM fungi was associated with increased leaf width,saturation fresh weight,chlorophyll content,soluble sugar content,and soluble protein content,and enhanced activities of peroxidase and catalase in L.chinensis.5)A membership function analysis showed that AM fungi can interact with C.virgata and improve the tolerance of L.chinensis in alkali habits.These results provide a theoretical basis for evaluating the effects of AM fungi and C.virgata as a companion plant on the growth of L.chinensis under alkali stress.These findings also provide important data to assist development of methodologies for the ecological restoration of Songnen saline-alkali grassland by introduction of appropriate companion plants and exploitation of mycorrhizal symbioses.