[Effects of arbuscular mycorrhizal fungi inoculation on non-structural carbohydrate contents and C:N:P stoichiometry of under drought stress].

A pot experiment was conducted to investigate the effects of drought stress and arbuscular mycorrhizal fungi (AMF) inoculation on C:N:P stoichiometry and non-structural carbohydrate (NSC) contents in two-year-old seedlings. There were four treatments, including control (CK), drought stress (D), AMF inoculation (AMF), and combined drought stress and AMF inoculation (D+AMF). The results showed that drought stress significantly reduced AMF colonization rate, whereas plant height and leaf number of inoculated treatment were significantly higher than the non-inoculated treatment. Inoculation with AMF significantly increased soluble sugar and NSC content in root and leaf, as well as starch content in stem and leaf. The inoculation significantly decreased the stem and leaf soluble sugar to starch ratio under drought stress. Drought stress caused a significant increase in C content in roots and leaves, and a significant decrease in P content in stems. Compared with no inoculation drought stress, P content in roots, stems, leaves, and C content in leaves of mycorrhizal seedlings were significantly increased by inoculation under drought stress, whereas root C and N content and stem C content were significantly reduced. Under drought stress, AMF inoculation significantly decreased C:N, C:P, and N:P ratios in roots and stems, and N:P ratios in leaves of . P content in roots and leaves were significantly positively correlated with soluble sugar and NSC content. Stem P content was significantly positively correlated with starch and NSC content. N:P ratios in each organ was significantly negatively correlated with NSC content. In all, inoculation with AMF can improve the drought tolerance of seedling by increasing soluble sugar content in roots and leaves and the soluble sugar/starch ratio in roots, improving starch content in above-ground organs, promoting the P absorption, and reducing N:P ratios in each organ. Therefore, AMF colonization could improve the survival rate of seedling in dry environments.