干旱和盐胁迫对华山新麦草种子萌发及幼苗生理特性的影响

模拟华山新麦草野生土壤生境特点,分别采用聚乙二醇(PEG-6000)、钙(CaCl2)以及二者混合液3种方式浸种,研究PEG-6000和Ca2+浸种对华山新麦草种子萌发及幼苗生长的影响.结果表明:3种处理下华山新麦草的种子发芽率、发芽势和发芽指数均无显著变化;但PEG-6000浸种后,华山新麦草幼苗可溶性糖和可溶性蛋白含量增加,蛋白酶、SOD和POD活性增强;CaCl2浸种后,华山新麦草幼苗可溶性糖含量增加,蛋白酶、SOD和CAT活性增强,淀粉酶活性降低;而PEG-6000和CaCl2混合液浸种后,华山新麦草幼苗可溶性糖含量下降,SOD活性降低,华山新麦草生长受阻.据此推测华山干旱和钙离子含量高的生境特点可能是华山新麦草种群濒危的原因之一.

Seed Germination and Seedling Physiological Characteristics in Psathyrostachys huashanica Keng under the Drought and Salt Stress

In this experiment,PEG-6000,CaCl2 and their mixture were applied to soak the seeds of Psathyrostachys huashanica Keng.Effects of soaking with PEG-6000 and Ca2+ on seed germination and seedling growth in P.huashanica Keng were studied.The results showed that after soaking with PEG-6000,CaCl2 and their mixture,there were no significant change in seed germination rate,germinability and germination index.Soaking seed with PEG-6000 increased the seedling leaf’s soluble sugar and protein contents,SOD,POD and protease activities.Soaking with Ca2+ increased the seedling leaf’s soluble saccharine contents,SOD,CAT and protease activities,decreased amylase activity.After soaking with PEG-6000,CaCl2 mixture,the SOD activity,soluble sugar content decreased in seedling growth.We conclude that drought and high content of Ca2+ may be one of the endangered factors of P.huashanica Keng.