几种旱生灌木种子萌发对干旱胁迫的响应

Response of seed germination of three xeromorphic shrubs to drought stress.

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) .

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～-2.7MPa). The results showed that under drought stress, C.korshinskii had the highest germination rate, while A.sphearocephala had the lowest one.Under -0.3～-0.6MPa, 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 3.1cm, respectively. There existed a significant positive correlation between seed germination rate and 72h 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.