NaCl胁迫对5种绿化植物幼苗生长和生理指标的影响及耐盐性综合评价

Effects of NaCl stress on growth and physiological indexes of five greening plant seedlings and comprehensive evaluation of their salt tolerance

采用分次浇灌的方法,对2、4、6、8和10 mg.g-1NaCl胁迫条件下光叶决明（Cassia floribunda Cav.）、紫穗槐（Amorpha fruticosa L.）、海滨木槿（Hibiscus hamaboSieb.et Zucc.）、决明〔Senna tora（L.）Roxb.〕和田菁〔Sesbaniacannabina（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-1NaCl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.