依据江苏滨海盐渍土的离子组成和含量,采用土培法研究了经0. 0(CK)、3. 0、5. 0 和8. 0 g·kg^-1 混合盐胁迫处理后江苏沿海常用绿化植物(包括16 种乔木和8 种灌木)的盐害指数、死亡率、苗高生长量和相对干质量;在此基础上,依据Logistic 方程和耐盐阈值(T50 )对各种类的耐盐性进行了初步评价。结果表明:随土壤中混合盐质量浓度的提高,各种类的盐害指数和死亡率总体呈逐渐升高的趋势,而苗高生长量和相对干质量总体呈逐渐下降的趋势,但不同种类各指标的变化幅度有明显差异。总体上看,经不同质量浓度混合盐胁迫处理后,乔木树种中‘中山杉406’(Taxodium hybrid ‘Zhongshanshan 406’)以及灌木树种中海滨木槿(Hibiscus hamabo Sieb. et Zucc.)、海桐[Pittosporum tobira (Thunb.) Ait.]和匍地柏[Sabina procumbens (Endl.) Iwata et Kusaka]植株全部存活且盐害指数低,而其他树种的死亡率较高甚至达到100%且盐害指数均较高;乔木树种中银杏(Ginkgo biloba Linn.)和‘中山杉406’以及灌木树种中海滨木槿、匍地柏、黄杨[Buxus sinica (Rehd. et Wils.) Cheng]和海桐的相对干质量较高;乔木树种中紫穗槐(Amorpha fruticosa Linn.)、海棠[Malus spectabilis (Ait.) Borkh.]和‘中山杉406’’以及灌木树种中海桐、匍地柏和海滨木槿的苗高生长量较高。此外,乔木树种中‘中山杉406’、女贞(Ligustrum lucidum Ait.)和海棠以及灌木树种中海滨木槿、海桐、匍地柏、黄杨、日本珊瑚树[Viburnum odoratissimum var. awabuki (K. Koch) Zabel ex Rumpl.页和石楠(Photinia serrulata Lindl.)的T50 值均较高。综合分析结果显示:刺槐(Robinia pseudoacacia Linn.)、银杏、台湾含笑[Michelia compressa (Maxim.) Sarg.]、白蜡树(Fraxinus chinensis Roxb.)、海棠、女贞、‘中山杉406’、石楠和日本珊瑚树可耐受低浓度的混合盐胁迫,黄杨和匍地柏可耐受中浓度的混合盐胁迫,而海滨木槿和海桐可耐受高浓度的混合盐胁迫。

Based on composition and content of ion of coastal saline soil in Jiangsu Province, salt-injury index, mortality rate, height increment and relative dry weight of common greening species (including sixteen arbors and eight shrubs) in coastal area of Jiangsu Province after treated by mixed salt stress with 0. 0 (CK), 3. 0, 5. 0 and 8. 0 g·kg^-1 were researched by soil culture method. On this basis, salt tolerance of all species was evaluated preliminarily by Logistic equation and salt-tolerance threshold (T50). The results show that with enhancing of mass concentration of mixed salt in soil, salt-injury index and mortality rate of all species generally appear the trend of increasing gradually, while height increment and relative dry weight generally appear the trend of decreasing gradually, but there is an obvious difference in change range of all indexes of different species. In general, after treated by mixed salt stress with different mass concentrations, Taxodium hybrid ‘Zhongshanshan 406’in arbor tree species and Hibiscus hamabo Sieb. et Zucc., Pittosporum tobira (Thunb.) Ait. and Sabina procumbens (Endl.) Iwata et Kusaka in shrub tree species all survive and their salt-injury indexes are low, while mortality rate of other tree species is higher, even reaches 100% with higher salt-injury index. Relative dry weight of Ginkgo biloba Linn. and T. hybrid ‘Zhongshanshan 406’ in arbor tree species and H. hamabo, S. procumbens, Buxus sinica (Rehd. et Wils.) Cheng and P. tobira in shrub tree species is higher. Height increment of Amorpha fruticosa Linn., Malus spectabilis (Ait.) Borkh. and T. hybrid  ‘Zhongshanshan 406’ in arbor tree species and P. tobira, S. procumbens and H. hamabo in shrub tree species is higher. Moreover, T50 value of T. hybrid ‘Zhongshanshan 406’, Ligustrum lucidum Ait. and M. spectabilis in arbor tree species and H. hamabo, P. tobira, S. procumbens, B. sinica, Viburnum odoratissimum var. awabuki (K. Koch) Zabel ex Rumpl. and Photinia serrulata Lindl. in shrub tree species is higher. The result of comprehensive analysis shows that Robinia pseudoacacia Linn., G. biloba, Michelia compressa (Maxim.) Sarg., Fraxinus chinensis Roxb., M. spectabilis, L. lucidum, T. hybrid ‘ Zhongshanshan 406’, P. serrulata and V. odoratissimum var. awabuki can be tolerant to low concentration of mixed salt stress, while B. sinica and S. procumbens do middle concentration of mixed salt stress, and H. hamabo and P. tobira do high concentration of mixed salt stress.