盐胁迫对柽柳和白刺幼苗生长与生理特性的影响

Effects of salt stress on growth and physiological characteristics of Tamarix chinensis and Nitraria tangutorum seedlings

【目的】分析比较青海柴达木地区2种植物的耐盐性,为青海地区更加合理地利用耐盐植物改良盐渍土提供科学依据。【方法】以柽柳(Tamarix chinensis)幼苗和白刺(Nitraria tangutorum)幼苗为材料,通过盆栽试验,研究各幼苗在不同含盐量(质量分数分别为0.25%(对照),0.40%,0.50%,0.60%,0.70%,0.80%)土壤中的生长情况及其生理特性的变化。【结果】(1)与对照相比,盐胁迫显著抑制2种幼苗的生长,含盐量低于0.40%的土壤对2种幼苗株高、地径增长量和全株鲜质量的影响基本相同;含盐量高于0.60%时,盐胁迫对白刺生长的影响大于柽柳;2种幼苗干质量下降率在盐胁迫的影响下基本无明显差异。(2)含盐量低于0.40%的土壤对2种幼苗叶片Na+、K+含量及Na+/K+值的影响基本相同;含盐量高于0.60%时,盐胁迫对白刺叶片Na+、K+含量的影响大于柽柳。(3)含盐量低于0.40%的土壤对2种幼苗净光合速率、蒸腾速率、气孔导度和胞间CO2浓度的影响基本相同;含盐量高于0.60%时,盐胁迫对白刺光合作用的影响大于柽柳。【结论】盐胁迫对白刺生理与生长特性的影响大于柽柳,柽柳具有更强的耐盐性,在青海柴达木地区,柽柳更适合在更高(>0.60%)含盐量的盐渍土中生长。

【Objective】This study analyzed and compared salt tolerance of two plants in Qaidam to provide scientific basis for improving saline soil in Qinghai.【Method】Taking Tamarix chinensis and Nitraria tangutorumseedlings as test materials,apot experiment was conducted to study their growth and physiological characteristics under different soil salt contents（mass fraction 0.25%（control）,0.40%,0.50%,0.60%,0.70%,and 0.80%）.【Result】（1）Compared with the control,salt stress significantly inhibited the growth and photosynthesis of two seedlings.When the soil salt content was less than 0.40%,it had the roughly same effects on height,diameter increment and fresh weight of two seedlings.When salt content was higher than 0.60%,the impact on the growth of N.tangutorum was greater than on T.chinensis.Under the influence of salt stress,two seedlings almost had no difference in dry mass dropping rate.（2）When the soil salt content was less than 0.40%,it had the roughly same effects on contents of Na＋and K＋and Na＋/K＋ratios of the two seedlings leaves.When salt content was higher than 0.60%,changes in Na＋and K＋contents of N.tangutorum were greater than that of T.chinensis.（3）When the soil salt content wasless than 0.40%,it had the roughly same effects on net photosynthetic rate,transpiration rate,stomatic conductance and intercellular CO_2 concentration among seedlings.When salt content was higher than0.60%,changing rates of all photosynthesis indexes of N.tangutorum were greater than those of T.chinensis.【Conclusion】Compared to N.tangutorum,T.chinensis seedling showed higher salt tolerance and was more suitable in the Qaidam region with higher salt content（〉0.60%）.