盐碱胁迫对光皮桦种子萌发及幼苗生长的影响

利用中性盐NaCl、Na2SO4和碱性盐NaHCO3按不同质量比混合,模拟出15种盐碱度各不相同的盐碱逆境条件,进行光皮桦种子萌发试验,研究盐碱胁迫对光皮桦种子萌发及幼苗生长的影响.结果表明,在不同盐碱处理下,随着盐浓度及pH值的增加,种子发芽率、发芽指数均呈下降趋势,对幼苗胚生长抑制作用加强;在pH≥8.78,盐浓度≥100mmol/L胁迫下,光皮桦种子的萌发明显受到抑制,且萌发进程延缓,当盐浓度高达250mmol/L时,各盐碱处理下的光皮桦种子均不萌发;在pH≥7.08,盐浓度50mmol/L胁迫下,光皮桦早期幼苗无法正常生长;碱性盐对种子萌发的抑制作用强于中性盐.

Effects of Saline-alkaloid Stress on Seed Germination and Seedling Growth of Betula Luminifera

The seed of Betula luminifera was treated with simulated fifteen kinds of different saline-alkaloid condition solution that mixed with neutral salts NaCl.Na2SO4 and alkaline salt NaHCOain different mass ratio to study the effect of different saline-alkaloid conditions on its germination and seed- ling growth. The results showed that with the increasing of salt concentration and pH, the germination rate, germination index of Betula luminifera seeds decreased, and the root radical and shoot hypocotyl growth of seedlings reduced obviously. Under pH≥7.08 and concentrationS100 mmol/L stress, the seed germination of Betula luminifera was inhibited significantly and the process 0f germination became slow. When the salt concentration was above 250 mmol/L, the seed germination was completely inhibited. Under pH≥7.08 and concentration〉50 mmol/L stress, the early seedlings of Betula lurninifera were unable to grow normally. The inhibitory effect of alkaline salt on seed germination was stronger than that of neutral salt.