In order to study morphological changes and physiological characteristics under salt stress, seedlings of 16 tree species were cultivated in pots treated with sodium chloride (NaCl) solutions of 0, 100, 200, 300, 400, and 500 mmol·L-1 and three replications. Results showed that (1) salt tolerance of Tamar-ix chinensis , Nitraria tangutorum, and Nitraria sibirica was high; of Euonymus alatus , Salix psammophila, Ligustrum obtusifolium, Elaeagnus angustifolia, Rhamnus cathartica, Celtis laevigata, and Gleditsia triacan-thos was medium-high; and of Pyrus betulifolia, Salix maizhokunggarensis , Lonicera tatarica, Buddieja lind-leyana, Cephalanthus occidentalis , and Fraxinus americana was medium. (2) With an increase in salinity, relative height growth and biomass significant decreased; however, the malondialdehyde (MDA), proline, and soluble sugar content marked increased for all species. Also, chlorophyll content and superoxide dismutase (SOD activity varied greatly among tree species. In addition, for all physiological indexes, Tamarix chinensis, Nitraria tangutorum, and Nitraria sibirica revealed marked differences from other species. (3) After applying salt treatments, Na+ and Cl- ions in roots, stems, and leaves greatly increased with both ions having a con-sistent increased. Differences in the Na+ and Cl content in roots, stems, and leaves showed that except for Tamarix chinensis, Nitraria tangutorum, and Nitraria sibirica, the 13 other tree species were halophytes that excluded salt. These results suggested that different tree species should be selected for the salt content of the soil, so that trees could be grown in suitable soils to increase biodiversity in saline soil. It is necessary to consider salt-tolerance type of plant in the study of plant salt tolerance characteristics.%采用盆栽控盐方法,以16个树种幼苗为材料,用不同浓度(0,100,200,300,400,500 mmol·L-1)氯化钠(NaCl)溶液进行浇灌处理,对盐胁迫下各树种的生长表现和生理特性进行了研究.结果表明:①柽柳Tamarix chinensis,唐古特白刺 Nitraria tangutorum 和西伯利亚白刺Nitraria Sibirica耐盐能力较强,卫矛Euonymus alatus,沙柳Salix psammophila,水蜡Ligustrum obtusifolium,沙枣 Elaeagnus angustifolia,药鼠李Rhamnus cathartica,糖朴Celtis laevigata和美国皂荚 Gleditsia triacanthos 具有中高度耐盐能力,而杜梨 Pyrus betulaefolia,竹柳Salix maizhokung-garensis,鞑靼忍冬Lonicera tatarica,醉鱼草Buddleja lindleyana,风箱树Cephalanthus occidentdis和美国白蜡Fraxinus americana相对较差,具有中度耐盐能力.②随盐浓度的增加,各树种的相对株高生长量和生物量下降,丙二醛(MDA),脯氨酸和可溶性糖增加,叶绿素和超氧化物歧化酶(SOD)活性树种间差异较大,柽柳、唐古特白刺和西伯利亚白刺的各生理指标与其他13个树种存在明显差异.③盐处理后,不同部位(根、茎和叶)钠离子(Na+)和氯离子(Cl-)明显增加,而且2种离子的变化规律基本一致,从Na+和Cl-在不同部位的分布情况差异可以初步判断除柽柳、唐古特白刺和西伯利亚白刺外,其他13个树种为拒盐型植物.在不同含盐量的土壤中,选择不同树种,做到适地适树,提高生物多样性,并且在研究植物耐盐特性时,需要根据植物耐盐类型加以区别对待.
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