3种白刺耐盐性的对比分析

以2年生西伯利亚白刺、齿叶白刺和唐古特白刺苗为材料,设置0、100、200、300、400 mmol.L-1NaCl 5种盐浓度开展胁迫试验,测定并对比分析其对盐胁迫的生长及生理生化响应。结果表明:低盐浓度处理促使白刺生长速度和生物量增加、叶绿素含量增高,高盐浓度处理下这种促进作用降低;在100 mmol.L-1的盐处理下,唐古特白刺、西伯利亚白刺、齿叶白刺叶绿素含量均达最高,分别为0.72、0.78、0.61 mg.g-1;在400 mmol.L-1的盐处理下,唐古特白刺、西伯利亚白刺、齿叶白刺生物量为最低,分别为10.49、12.42、10.19 g.株-1,仅为对照的75%79%;3种白刺中,唐古特白刺的Na+/K+最高,施盐处理下西伯利亚白刺的Na+/K+均高于对照,而齿叶白刺则低于对照;随着盐浓度的增加,3种白刺叶片中可溶性蛋白的含量递增,可溶性糖含量则先增后减;低盐浓度处理的唐古特和西伯利亚白刺叶片中MDA含量比对照低,齿叶白刺却比对照高;3种白刺的POD和SOD活性在盐处理下高于对照,其中唐古特白刺叶片中POD活性最低,齿叶白刺中SOD活性最高;3种白刺在盐胁迫下均能正常生长。

Comparative Analysis of Salt Tolerance of Three Nitraria Species

In this study, two-year-old Nitraria sibirica Pall., N. tangutorum Bobr. and N. roborowskii Kom. were used as plant material. Treated by five salt concentrations (0, 100, 200, 300 and 400 mmol·L^-1 NaCl), the physiological and biochemical responses of these species under different salt stress were compared and analyzed. The results showed that low salt concentration promoted the growth of Nitraria and increased the biomass and chlorophyll content while decreased at high concentration. The chlorophyll contents of N. tangutorum, N. sibirica and N. roborowskii were the highest at 100 mmol·L^-1 salt concentration, which were respectively 0.72, 0.78, and 0.61 mg·g^-1; The biomass of N. tangutorum, N. sibirica and N. roborowskii were the lowest at 400 mmol·L^-1 salt concentration, which were respectively 10.49, 12.42, and 10.19 g; Under salt stress, the maximum content of Na⁺/K⁺ was found in N. tangutorum. The Na⁺/K⁺ contents of N. sibirica were higher than the CK group, while that of N. roborowskii was lower than the CK group. With the salt concentration increased, the content of soluble sugar increased at initial and then decreased, and the soluble protein of all the three Nitraria species increased. In the low salt concentration, the MDA was higher than the CK group in the N. tangutorum and N. sibirica, while the N. roborowkii was the opposite. The activity of POD and SOD were higher under salt environment, the N. tangutorum had lowest POD activity while the N. roborowskii had the highest SOD activity. Three Nitraria species can maintan normal growth in saline environment.