几种旱生灌木种子萌发对干旱胁迫的响应

以不同渗透势的PEG(6 0 0 0 )溶液 (- 0 .3～ - 2 .7MPa)为模拟干旱胁迫条件 ,研究了柠条 (Caraganakorshinskii)、花棒 (Hedysarumscoparium)和白沙蒿 (Artemisiasphaerocephala)种子发芽、幼苗生长和累积吸水率对干旱胁迫的响应 ,讨论了参试种子发芽特性、初生根长度与幼苗建植成活率的关系 .结果表明 ,干旱胁迫下柠条发芽率最高 ,其次为花棒 ,白沙蒿最低 . - 0 .3～ - 0 .6MPa渗透势下白沙蒿发芽 10d的初生根长度显著大于花棒和柠条 (P <0 .0 5 ) ,三者的测量值依次为 7.9、4 .5和 3.1cm .干旱胁迫条件下参试种子发芽率与种子 72h累积吸水率均呈极显著的正相关 (P <0 .0 1) .

Response of seed germination of three xeromorphic shrubs to drought stress

The seed germination, seedling growth and water absorption characteristic of Caragana korshinskii, Hedysarum scoparium, and Artemisia sphearocephala were investigated under different osmotic potentials (PEG 6000, -0.3(-) -2.7 MPa). The results showed that under drought stress, C. korshinskii had the highest germination rate, while A. sphearocephala had the lowest one. Under -0.3(-) -0.6 MPa, the root length of 10-day-old A. sphearocephala seedling was significantly longer than that of H. scoparium and Caragana korshinskii(P < 0.05), and the length reached 7.9, 4.5 and 3.1 cm, respectively. There existed a significant positive correlation between seed germination rate and 72 h water absorption rate of the three shrub seeds(P < 0.01). The relationships among germination characteristics, root length, and survive percentage of seedlings were also discussed.