|Other Abstract||Tarim desert highway is one of the southern Xinjiang transportation lifeline. TaklimakanDesert frequent and intense of sand blown by wind are a serious threat to the desert highway, and its mechanical sand prevention system. To biological sand control measures as the main body of the Tarim Desert Highway Shelterbelt ecological engineering construction can not only protect the desert highway unblocked, but also improve ecological environment. The research on plant resistance is the basic work of plant species selection and regeneration in the ecological engineering construction of desert highway shelter forest. In order to ensure the biological sand control system's stability and the hinterland of the desert oil field workers living environment greening requirements are required to provide suitable plant species. In this context, we carry out in the hinterland of the Taklimakan desert plant resistance research work, and provide a basis for the tower area suitable for the plant species of the comprehensive selection.
This study in Haloxylon ammodendron（C.A.Mey.） Bunge, Caragana korshinkii
and Calligonum caput-medusae Schrenk experimental materials of three kinds of plant seeds and seedlings of different degrees of artificial sand burial （including blank control, sand burial 1/3, 2/3 sand burial, 3/3 sand buried four treatments） physiological and ecological response. Through the determination of three species of plant height, crown width, seedling leaf relative water content （RWC）, MDA, SOD and POD, Sugar, chlorophyll （Chl） and photosynthetic parameters and analysis of sand buried for three plant seedlings physiological ecology were studied. The results showed that:
（1） In different sand buried treatment under three kinds of plant seedling high showed decreased at first and then increased and then decreased trend, and in 2/3 of the sand buried height reaches the maximum value, 1/3 and 3/3 sand buried inhibited the growth of seedlings of mountain plants, and two thirds of the sand buried a certain role in promoting the growth of plant seedling.
（2） H. ammodendron, C. korshinkii, C. caput-medusae three plant seedlings in different sand buried leaves relative water content is realized for 1/3 > 2/3 > CK > 3/3, with sand burial time increase leaf relative water content showed a decreasing trend, the different species of the leaf relative water was H. ammodendron > C. caput-medusae > C. korshinkii, but between the treatments do not exist significant differences to the realization of content, indicating that in sufficient water Xiasha burial stress on plant seedling leaf relative water content has little effect.
（3） Under sand burial stress, the MDA content will increase or decrease in different degree. The research results show that: H. ammodendron with time increase MDA content first increased and then decreased, because C. korshinkii and C. caput-medusae with time increase MDA content decreased gradually. The content of MDA that increases with the time extension of the plant in the accumulation of free radical increased, membrane lipid peroxidation increased seedlings affected increases, with time to extend the MDA content decreased plant in vivo free radical gradually cleared, membrane lipid peroxidation of slow, seedlings subjected to the effect of slow. When the sand buried time reached 30 d, three kinds of plant seedlings were all killed in S3 treatment, which showed that the whole plant had been forced to reach irreversible damage.
（4） With sand burial degree increasing and sand burial time prolonged,C. korshinkii seedling soluble sugar content than the other two plants always maintain the at a higher level, indicating that the synthesis more soluble sugar involved in osmotic adjustment, to adapt to environmental stress. In comparison, the soluble sugar content of three kinds of plant seedlings was affected by sand burial 10d, but the change was not significant, which showed that there was no significant damage to the membrane system in the early stage of sand burial stress.
（5） In the sand burial stress rise of H. ammodendron and C. caput-medusae seedling leaves and the SOD activity in the early, with sand burial stress time prolonging, stress in the late H. ammodendron seedling leaves and the SOD activity decreased but still maintained at a higher level that with sand buried time extension of H. ammodendron and C. caput-medusae seedlings to establish a stable protective enzyme SOD activity system active oxygen metabolism in a certain balance. C. korshinkii seedling leaves and the SOD activity with sand burial stress time prolonging continued to decline, and MDA content than other two plants remained at a high level, indicating that C. korshinkii SOD synthesis ability is weak, sand burial stress has a great influence on the physiology. H. ammodendron and C. korshinkii seedling leaf POD activity in different sand burial stress decreased first and then increased along with the increase in the time of sand burial, and H. ammodendron continued to increase, under different stress factors of three kinds of plant of pod and SOD activity increased and no obvious synchronization.
（6） With different levels of sand buried no notable regular change of plant Chla content, but when the sand burial S3 showing plant chlorophyll content was slightly decreased, indicating mild sand burying on three kinds of plant Chla content had no significant effect. However, the content of Chla was obviously increased with the increasing of sand burying time.
（7） H. ammodendron and C. korshinkii in sand burial 10d with sand burial depth increased the content of Chlb is essentially the same, and C. caput-medusae chlorophyll b content decreased gradually. It showed that the decrease of Chlb content in short sand buried treatment decreased the probability of ROS production, and even did not produce excessive reactive oxygen species, which is the common character of these three kinds of plants. The content of Chlb in leaves of three kinds of plant seedlings was significantly increased with the time of sand burying. With the sand burial time up to 30 days of H. ammodendron seedlings Chlb content began to decrease, C. caput-medusae Chlb content in stable level, little change. It shows that long sand burial can cause some damage to the plant body.
（8） Sand burial stress under three kinds of plant Chl a/b ratio changes, the H. ammodendron seedlings Chl a/b value increases with the depth of sand burial trend of decreased first and then increased, probably because of a certain degree of sand burial reduces the stability of thylakoid membranes, but with the degree of sand burying increase plant in order to maintain their own materials necessary for growth and improve its resistance, so that the stability of thylakoid membrane increased and increased photosynthesis. C. korshinkii with sand buried the extension of time and sand burial depth increased Chla/b value decreases gradually, indicating that the sand burial stress on growth of C. caput-medusae caused certain persecution, which affected the photosynthesis.|