Abstract:
The increasing global phenomenon of soil salinization has prompted heightened interest in the physiological ecology of plant salt and alkali tolerance. Halostachys caspica belonging to Amaranthaceae, an exceptionally salt-tolerant halophyte, is widely distributed in the arid and saline-alkali regions of Xinjiang, in Northwest China. Soil salinization and alkalinization frequently co-occur in nature, but very few studies focus on the interactive effects of various salt and alkali stress on plants. In this study, the impacts on the H. caspica seed germination, germination recovery and seedling growth were investigated under the salt and alkali stress. The results showed that the seed germination percentage was not significantly reduced at low salinity at pH 5.30-9.60, but decreased with elevated salt concentration and pH. Immediately after, salt was removed, ungerminated seeds under high salt concentration treatment exhibited a higher recovery germination percentage, indicating seed germination of H. caspica was inhibited under the condition of high salt-alkali stress. Stepwise regression analysis indicated that, at the same salt concentrations, alkaline salts exerted a more severe inhibition on seed germination, compared to neutral salts. The detrimental effects of salinity or high pH alone were less serious than their combination. Salt concentration, pH value, and their interactions had inhibitory effects on seed germination, with salinity being the decisive factor, while pH played a secondary role in salt-alkali mixed stress.
摘要:
全球土壤盐渍化现象的增加促使人们对植物耐盐碱生理生态学的兴趣增强。Halostachyscaspica,属于Amaranthaceae,一种特别耐盐的盐生植物,广泛分布在新疆的干旱和盐碱地区,在中国西北地区。土壤盐渍化和碱化在自然界中经常同时发生,但是很少有研究关注各种盐碱胁迫对植物的交互影响。在这项研究中,对鼠尾草种子萌发的影响,研究了盐和碱胁迫下的发芽恢复和幼苗生长。结果表明,在pH5.30-9.60的低盐度下,种子发芽率没有显着降低,但随着盐浓度和pH的升高而降低。紧接着,盐被去除,未发芽的种子在高盐浓度处理下表现出更高的恢复发芽率,表明在高盐碱胁迫条件下,caspica种子萌发受到抑制。逐步回归分析表明,在相同的盐浓度下,碱性盐对种子萌发有更严重的抑制作用,与中性盐相比。单独的盐度或高pH的有害影响不如其组合严重。盐浓度,pH值,它们的相互作用对种子萌发有抑制作用,盐度是决定性因素,pH在盐碱混合胁迫中起次要作用。