干旱区生态环境知识资源中心

Germination behaviour plays an important role for seedling regeneration and the sustainable development of population in arid and semiarid areas. The objectives of the study were to explore germination characteristics of Anabasis aphylla and Haloxylon ammodendron under low temperature conditions and their ecological significance in Junggar basin of China We combined the Logistic function and the thermal time equation, and used non-linear regression to estimate the base temperature and the thermal time for germination of both species. Germination experiments were carried out in the illumination incubators with 6 temperature gradients (20/15 degrees C, 15/10 degrees C, 10/5 degrees C, 5/2 degrees C, 2 degrees C and 2/3 degrees C) for 15 days. Final germination percentages of the two species were not obviously different and were higher than 90% in different temperature treatments, and low temperature only inhibited germination speed. Moreover, germination percentages of the two species surpassed 50% in the eighth day under low temperature conditions. The base temperature and thermal time of A. aphylla was 0.54 degrees C and 9.89 degrees C, while H. ammodendron was 0.79 degrees C and 7.26 degrees C, respectively. The results showed that the two desert species adapted to the low temperature habitat and took advantage of humid soil conditions to grow in the snow-melting period.