Effect Of Arbuscular Mycorrhizal Fungi On The Physiology And Growth Of Zelkova Serrata Under Acidity Stress

Acid rain incurred by environmental pollution is the main driver for acid stress,especially in Zhejiang province,which is one of the main acid rain monitoring sites in China.It is studied that the acid rain type of Lin'an,Hangzhou is the mixture of sulfuric acid and nitric acid.Some studies have shown that AM fungi can modulate the detrimental effects of acidity stress to plants,but its underlying mechanism is still uncertain.Aiming to solve these scientific questions,Zelkova serrata was used as the objective species in a greenhouse experiment to explore regulative mechanism on the physiological growth of Z.serrata inoculated with four levels of AM fungi(sterilized AM fungi,NM;Glomus intraradices,Gi;G.versiforme,Gv and in combination of G.intraradices and G.versiforme,Gi+Gv)and treated with three levels of acidity stress(p H5.6,p H4.0,p H2.5)of sulfuric acid type and mixed type.So then to provide theoretical and practical basis for the planting and management of subtropical evergreen broadleaved forest in acid control area of Zhejiang.The results showed that:(1)While both of sulfuric acidric and mixed acidity stresses could significantly decrease the growth of Z.serrata.However,inoculation with AM fungi can modulate the detrimental effects of acid stress on the growth which significantly increase the total dry weight,leaf area,photosynthesis related parameters and related enzyme activities of Z.serrata,(2)The regulation of AM fungi on plants may be exerted by improving the activity of ALP,SDH and leaf area under sulfuric acid type acidity stress.While under mixed acidity stress,increasing plant enzyme activity and solube protein content maybe the underlying mechanism for the regulation of AM fungi on the growth of Z.serrata.(3)Specific AM fungi have varied regulatory effects on the growth of Z.serrata.Gv-inoculation was the most effective one to promote the growth of Z.serrata under sulfuric acid type acidity stress.Under p H2.5 treatment,combination inoculation could better promote the growth of Z.serrata as compared to the pure AM fungi,while under the condition of p H5.6 and p H 4.0,Gv-inoculation could be the better choice for improving the growth of Z.serrata in relative to the combination inoculation.