极端干旱条件下策勒绿洲引种植物水分生理特征研究

Water physiological characteristics of introduced plants under extreme drought conditions in Cele Oasis

在塔克拉玛干沙漠南缘的中国科学院策勒沙漠研究站植物引种筛选实验区内,以3 a生文冠果、花棒和紫叶小檗为实验材料,研究三种植物经历持续干旱到短期复水过程中的生理生态响应。结果表明:(1)干旱复水后花棒和紫叶小檗的chla、chlb、叶绿素总量以及chla/b值均随土壤含水量的增加而显著增加,文冠果的叶绿素及其组分含量减少。水分变化对chla含量影响较大。(2)三种植物的MDA含量、SS含量在复水后并没有减少,而是显著的增加,文冠果的增加量最大;各物种的脯氨酸的含量降低,紫叶小檗减少的最多。(3)三种植物的清晨水势和正午水势随土壤水分含量的增加而降低,花棒和紫叶小檗的水势变化较小,水分亏缺迹象不显著。文冠果和花棒的抗逆性较强,而紫叶小檗对水分变化比较敏感。本研究结果可为研究区引种植物的适应性及防护林建设中的植物种选择提供理论参考。

The southern edge of the Taklimakan Desert is one of the most serious desertification areas in China. Natural vegetation type is scarce in desert-oasis transition zone, and Alhagi sparsifolia, Tamarix ramosissima and Karelinia caspica are the main constructive species and dominant plants. Therefore, it is necessary to introduce some new species which have strong drought resistance, high water use efficiency and high economic values. Three kinds of three-year-old sand fixing plants, Xanthoceras sorbifolia （X） Bunge, Hedysarum scoparium Fisch.et Mey （H） , and Berberis thunbergii cv. Atropurpurea （B） were taken as the experimental materials in this experiment, their physio-ecological responses in the period from persistent drought to short-time re-watering were investigated in this area. The purpose of this paper was to understand physiological and ecological responses of the three intro- duction plants to soil moisture changes. The results showed that re-watering after drought stress due to the increase of soil moisture results in increase in chla, chlb, chl and chla/b of H and B significantly, while the four indexes of X reduce. Soil moisture changes had relatively larger impact on the chla. Total chlorophyll of H and B increased by 46.13%, 60.26%, but X decreased by 21.32%. MDA and SS contents of the three plants did not decrease hut a sig- nificant increase and both index of X increased dramatically, 206.32% and 199.40% respectively; while the Pro con- tent was inordinately lower and B had a big reduction, which is 87.86%. The morning and noon water potential ofthree species declined with the increase of soil moisture;morning potential reduction of three plants were 113.23%, 100.59%, 90.97% and morning potential reduction of three plants were 86.92%, 5.74%, 11.20% respectively. Espe- cially, water potential of H and B changed relatively smaller, which showed that signs of water deficit of the two plants was not significant. Compared to the three plants, X and H had a strong resistance to drought, and B was more sensitive to soil moisture change. On the one hand, the innovative point of our experiment is to select three plants un- der natural conditions which experienced drought and sporadic rainfall and compare the physiological and biochemi- cal index and water potential changes of three plants to analyze the drought resistance and environmental adaptabili- ty of them. On the other hand, our experiment has a good application value. The results provide theoretical references for introduced plants adaptability and plant species selection in shelterbelt construction in the research area.