Arbuscular mycorrhizal fungi improved plant growth and nutrient acquisition of desert ephemeral Plantago minuta under variable soil water conditions

Desert ephemeral plants play an important role in desert ecosystem.Soil water availability is considered as the major restrictive factor limiting the growth of ephemeral plants.Moreover,arbuscular mycorrhizal fungi（AM fungi） are widely reported to improve the growth of desert ephemerals.The present study aimed to test the hypothesis of that AM fungi could alleviate drought stress of desert ephemeral Plantago minuta,and AM fungal functions reduced with the improvement of soil water content.A pot experiment was carried out with three levels of soil water contents（4.5%,9.0%,and 15.8%（w/w））,and three AM inoculation treatments（Glomus mosseae,Glomus etunicatum and non-inoculation）.The results indicate that mycorrhizal colonization rate decreased with the increase of soil water availability.Inoculation improved plant growth and N,P and K acquisition in both shoots and roots regardless water treatments.When comparing the two fungi,plants inoculated with G.mosseae performed better than those inoculated with G.etunicatum in terms of plant growth and nutrient acquisition.These results showed that ameliorative soil water did not suppress arbuscular mycorrhizal fungal functions in improving growth and nutrient acquisition of desert ephemeral Plantago minuta.

Foliar stoichiometry under different mycorrhizal types in relation to temperature and precipitation in grassland

Aims mycorrhizas play key roles in important ecosystem processes and functions.Carbon(C),nitrogen(N)and phosphorus(P)concentrations and their ratios are very important foliar traits and their cycling constrains most ecosystem processes.thus,this study addresses the influence of mycorrhizal strategies on these foliar nutrients and their response to climate change.Methods a new database was established including mycorrhizal types and leaf C_(mass),N_(mass),P_(mass),C:N and N:P of each plant species based on He et al.[(2008)leaf nitrogen:Phosphorus stoichiometry across Chinese grassland biomes.oecologia 155:301-10].the predomi-nant type of mycorrhizal association of each plant species was classified according to the published literature and our own obser-vations.We analyzed leaf C_(mass),N_(mass),P_(mass),C:N and N:P among 112 plant species in 316 samples of ascertained mycorrhizal type in the major grassland biomes of China.Important Findingsthe results show highly significant variation among different myc-orrhizal strategy types for foliar C_(mass),N_(mass) and N:P.the highest foliar C_(mass) was observed in ectotrophic mycorrhiza(ECM)type(469.8mg g1)followed by that in arbuscular mycorrhiza(AM)type(443.884 mg g1)and nonmycorrhizal(NM)type(434.0 mg g^(-1)).The foliar N concentration was significantly higher in NM type(31.0mg g^(-1)).However,the AM type had the greater C:N value(19)than the other types although less variation in C_(mass) and N:P among abuscular types on AM strategy was observed.Foliar traits showed significant variation in response to precipita-tion(mean growing season and annual precipitation(GSP and MAP))and temperature(mean growing season and annual tem-peratures(GST and MAT))depending on different mycorrhizal strategies and arbuscular types.When the responses of all folia parameters to precipitation and temperature were compared,the influence of GSP on leaf traits was greater than the influence of GST.