采用分次浇灌的方法,对 2、4、6、8 和 10 mg· g^-1 NaCl 胁迫条件下光叶决明( Cassia floribunda Cav.)、紫穗槐(Amorpha fruticosa L.)、海滨木槿( Hibiscus hamabo Sieb. et Zucc.)、决明[ Senna tora ( L.) Roxb.] 和田菁[ Sesbania cannabina (Retz.) Poir.]幼苗的 3 个生长指标和 6 个生理指标的变化进行了测定和分析,采用相关性分析、主成分分析(PCA)与隶属函数法相结合的方法对 5 种植物对 NaCl 的耐性进行了鉴定和综合评价,并利用回归分析确定了 5 种植物的生长临界 NaCl 浓度(C₅₀ )。 结果表明:在 2 ~ 10 mg· g^-1 NaCl 胁迫条件下,5 种植物幼苗的株高生长量和全株干质量总体上小于对照,且总体上随着 NaCl 质量浓度的提高而降低。 随 NaCl 质量浓度的提高,5 种植物幼苗的相对电导率、叶绿素含量、丙二醛含量、脯氨酸含量、可溶性糖含量和 SOD 活性均受到不同程度的影响,说明5 种植物对 NaCl 胁迫的响应不同。 除 MDA 含量外,5 种植物的生长和生理指标间大多存在显著或极显著的相关性。 通过主成分分析和隶属函数法获得的 5 种植物的综合评价值 D 及 C₅₀均表明田菁和海滨木槿对 NaCl 的耐性较强,其次为紫穗槐和决明,光叶决明对 NaCl 的耐性最差。

 

The changes of three growth indexes and six physiological indexes of seedlings of Cassia floribunda Cav., Amorpha fruticosa L., Hibiscus hamabo Sieb. et Zucc., Senna tora ( L.) Roxb. and Sesbania cannabina (Retz.) Poir. were determined and analyzed under NaCl stress conditions with 2, 4,6, 8 and 10 mg · g^-1 by franctional irrigation method. And the tolerance of five plants to NaCl was identified and comprehensively evaluated by correlation analysis method and principal component analysis method (PCA) combined with subordination function method, and the growth critical NaCl concentration (C50) of five plants was calculated by regression analysis. The results show that under 2 -10 mg· g^-1 NaCl stress conditions, height increment and dry weight of whole plant of seedlings of five plants are generally lower than those of the control, and generally decrease with enhancing of NaCl concentration.With rising of NaCl concentration, relative conductivity, contents of chlorophyll, MDA, proline and soluble sugar, SOD activity of seedlings of five plants are affected with different degrees, indicating that the response of five plants to NaCl stress is different. And growth and physiological indexes of five plants mostly appear significant or obviously significant correlation except MDA content. The comprehensive evaluation value D obtained by PCA-subordination function method and C₅₀ all indicate that the tolerance of S. cannabina and H. hamabo to NaCl is stronger, that of A. fruticosa and S. tora is weaker, that of C. floribunda is the weakest.