To investigate the effects of salicylic acid（SA）， nano-zinc oxide（ZnO NPs） and growth-promoting endophytic fungus YZ13-1（Fusarium graminearum） on drought tolerance of Fraxinus mandshurica seedlings. Two years old potted F. mandshurica seedlings were used as materials and 5 groups of treatments were set in this experiment：T1，drought stress treatment （soil water content was 20%-25%）； T2， T3 and T4 groups were additionally treated with 50 mg·L-1 SA，100 mg·L-1 ZnO NPs， growth-promoting fungus YZ13-1 suspension on the basis of T1 group； CK， control group（soil water content was 50%-55%）. The results showed that compared with T1 group， the activities of peroxidase（POD）， ascorbate peroxidase（APX）， catalase（CAT） were increased by 2 times， soluble sugar（SS）， proline（PRO） and phenolic substances increased by 44%， 60%， 16%， and relative electrical conductivity（RWC） of leaves decreased by 14% in T2 group. Compared with endophytic fungi and ZnO NPs， SA could significantly increase the anti-stress enzyme activity， increase the contents of osmotic substances and phenolic substances， and thus improve the drought resistance ability of F. mandshurica under drought stress. The study clarified that three induction treatments could improve the drought resistance of F. mandshurica， and SA treatment was the best， providing a theoretical basis for screening drought resistance agents of F. mandshurica.
%U https://bbr.nefu.edu.cn/EN/10.7525/j.issn.1673-5102.2023.03.008