Abstract: We used Pseudomonas sp. XSB5 and Yorkella sp. GG10 as the test strains to explore the effects of endophytic bacteria with the ability of phosphorus solubilization and production of siderophore and IAA on nutrient uptake of Xanthoceras sorbifolia Bunge seedlings. The seeds of X. sorbifolia were immersed in the bacterial solution. After the first euphylla grew, X. sorbifolia seedlings were treated with the same amount of bacterial solution or water, and the growth of X. sorbifolia was analyzed four months later. The results showed that root and aerial part dry weights of X. sorbifolia were significantly increased after treated with XSB5 bacterial solution. After treated with GG10 bacterial solution, root and aerial part dry weights of X. sorbifolia were increased, and the root part dry weights increased significantly. The accumulation of nitrogen, phosphorus, and magnesium in X. sorbifolia was significantly enhanced, and the accumulation of iron varied with the treatment duration. The translocation factors of those four mineral elements were different depending on the treatment duration of different bacterial solutions. The available nitrogen and phosphorus contents in the culture substrate were significantly increased (except XSB530 treatment), and the available magnesium and iron contents were not significantly different compared to the control. Our results indicated that the inoculation of two endophytic bacteria could affect mineral elements in the culture substrate, increase the uptake of mineral elements by X. sorbifolia, change the transport capacity of mineral elements upwards, and promote the growth of X. sorbifolia. This study provides substaintial basis for the screening of the growthpromoting bacterial fertilizer.

Key words: leaf surface feature, low-temperature stress, cold resistance., physiological index