试验以采自内蒙古阿拉善荒漠4种优势植物:梭梭、红砂、驼绒藜和碱蓬种子为材料,在0～1.8 mol/L的NaCl范围内,研究了盐分胁迫对种子萌发的影响,探讨了经NaCl浸种预处理后种子的萌发恢复能力.结果表明,随NaCl浓度的升高,梭梭、红砂、驼绒藜和碱蓬种子的萌发和初生根生长均受到不同程度的抑制,总体来看,盐溶液浓度越高,抑制作用越明显.但轻度的NaCl胁迫可提高碱蓬种子的发芽率、发芽指数,促进驼绒藜种子的萌发.4种荒漠植物种子萌发的盐度阈值分别为1.8,0.6,0.9和0.5 mol/L,说明梭梭种子萌发的耐盐性最强,而碱蓬的耐盐性最弱.经NaCl浸种预处理的种子在适宜条件下可以恢复萌发,但浸种时间越长,种子受盐胁迫的影响越大,甚至其萌发完全被抑制.短时间的NaCl浸种预处理提高了红砂种子的发芽率,并显著提高了其发芽指数,刺激了梭梭、红砂和驼绒藜的初生根生长,而碱蓬的初生根生长则一直受到NaCl浸种预处理的抑制.%The seeds of four important desert plants: Haloxylon ammodendron , Reaumuria soongorica , Cera-toides lateens , and Suaeda glauca were collected from the Alashan arid desert, Inner Mongolia. A series of laboratory tests were conducted to study the effects of salt stress on seed germination using NaCl solutions ranging from 0 to 1. 8 mol/L, and on germination recovery under optimum conditions after presoaking in NaCl solutions. Germination and radical growth of the four desert plants were subject to different degrees of inhibition with increasing NaCl concentration. In conclusion, the higher the salt concentrations, the greater the inhibitory effects and a slight salt stress improved the germination percentage and index of S. glauca and germination percentage of C. latens. The highest threshold concentrations of NaCl for germination were 1. 8 mol/L ( H. am modendron) , 0. 6 mol/L (R. soongorica) , 0. 9 mol/L (C. latens), 0. 5 mol/L (S. glauca). H. ammodendron therefore had the strongest salt tolerance, and S. glauca the weakest. Under optimum conditions, the seeds presoaked in NaCl solutions could recover their germination capability after the salt stress was relieved. Seeds presoaked for a longer time suffered a greater impact from salt stress, even completel suppression of germination. Presoaking a short time significantly improved germination percentage and index of R. soongorica and also stimulated the radical growth of H. ammodendron, R. soongorica, and C. . lateens, but the radical growth of S. glauca was always suppressed by presoaking.
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