Abstract: The effects of different NaCl concentration treatments (0,50,100,200,300 mmol·L^-1) on the growth and physiological characteristics of Carex leucochlora were tested to explore the physiological adaptation mechanism of C. leucochlora to salt (NaCl) stress. The results showed that different concentrations of NaCl stress had different effects on the growth inhibition of C. leucochlora. Low concentration of salt (50 mmol·L^-1) has no significant effect on the growth of C. leucochlora,but when the stress was over 8 d,the relative conductivity of the leaves was significantly increased. High concentration of salt (≥ 100 mmol·L^-1) significantly inhibited the growth of C. leucochlora,with the increase of salt concentrations and stress time,the leaf relative water content and chlorophyll content showed a downward trend,the withered leaf rate,leaf relative conductivity,malondialdehyde (MDA) content showed an increasing trend,and the activities of superoxide dismutase (SOD) and peroxidase (POD) increased at first and then decreased. The regression equation established based on the establishment of salt concentrations when the weight and biomass decreased by 50% determined that the critical concentration of C. leucochlora was 231.29 mmol·L^-1. In summary,the C. leucochlora shows a certain salt tolerance under low salt or short-term high salt stress.

Key words: Carex leucochlora, Salt stress, Salt tolerance, Growth characteristics, Principal components analysis

摘要： 为探究青绿苔草(Carex leucochlora)对盐(NaCl)胁迫的生理适应机制，本试验以青绿苔草'四季’为材料，采用盆栽试验，研究不同浓度(0，50，100，200和300 mmol·L^-1)NaCl胁迫对其生长和生理特性的影响。结果表明：不同浓度NaCl胁迫对青绿苔草生长抑制作用不同。低浓度盐(50 mmol·L^-1)对青绿苔草生长影响不显著，但胁迫8 d以上，叶片相对电导率显著提高。高浓度盐(≥100 mmol·L^-1)显著抑制青绿苔草生长，随着盐浓度提高和胁迫时间的延长，青绿苔草叶片相对含水量、叶绿素含量呈下降趋势；枯叶率、叶片相对电导率、丙二醛(Malondialdehyde，MDA)含量则呈升高趋势；超氧化物歧化酶(Superoxide dismutase，SOD)和过氧化物酶(Peroxidase，POD)活性呈先升高后降低的趋势。根据主成分分析和生物量下降50%时盐浓度建立回归方程确定青绿苔草耐盐临界浓度为231.29 mmol·L^-1。综上，青绿苔草在低盐或短期高盐胁迫下，表现出一定的耐盐性。

关键词: 青绿苔草, 盐胁迫, 耐盐性, 生长特征, 主成分分析