Abstract:The radial transport of nutrients in xylem ray tissues is very important for plant growth and development. At present, there are few studies on the radial transport rate of xylem ray tissues. With the dynamic changes of the age/seasonal growth and development of Haloxylon ammodendron, the characteristics of radial transport of xylem assimilation products are not clear. In this paper, H. ammodendron, a dominant species in the Gurbantunggut desert, was used as a test material to study the radial transport rate of nonstructural carbohydrates (NSC) in xylem of different ages and seasons. The relations between the NSC and anatomy of the xylem rays as well as vessels were analyzed. The results showed that: (1) the anatomical features of vessel and ray were increased with the tree age. The vessel length and vessel diameter of H. ammodendron were higher in May than that in July and October. The ray height, ray width and wall thickness of ray cell of H. ammodendron were higher in October than that in May and July. (2) The radial transport rate of NSC, soluble sugar and starch in H. ammodendron xylem increased significantly with the tree age (P < 0.05). There was no obvious difference between 13yearold and 18yearold trees in the radial transport rate of NSC, soluble sugar and starch (P > 0.05). (3) In different seasons, the radial transport rate of NSC was higher in May and October than that in July (P < 0.05). The radial transport rate of soluble sugar in H. ammodendron was the highest in May, followed in October, and then in July, and the difference between seasons was significant (P < 0.05). The starch radial transportation rate was decreased from May to October, and the seasonal difference was significant. (4) There was a significant positive correlation between vessel length and the radial transport rate of soluble sugar, vessel diameter and the radial transport rate of soluble sugar (P < 0.01), ray height and the radial transport rate of soluble sugar (P < 0.01), vessel diameter and the radial transport rate of NSC (P < 0.01) as well as ray height and the radial transport rate of NSC (P < 0.01). The radial transport function of H. ammodendron xylem was related to the anatomical structure of wood ray and vessel, and shows obvious seasonal dynamics.