Study On Salt Tolerance Of Coastal Tree Species In Northern Jiangsu Province

In this study, one-year-old seedlings of 10 tree species grown in two different pots containing soils, these are no salt soil and saline soil,were subjected to salinity(Na Cl) treatments in order to determine their salt tolerance. we observed and measured 23 indicators related to salt tolerance of these seedings, including the survival rate, the salt damage index of the leaves, the biomass, the root/shoot ratio, the proline contents, the soluble sugar contents, the membrance permeability, the net photosynthetic rate, the stomata conductance, the intercellular CO2 contentration, the transpiration rate and organic mineral elements. By subordinate function, we evaluate efficiently the seedlings’ salt tolerance. The result shows:(1)From the aspect of the survival rate and the salt damage index of the leaves, the survival rate of Alnus spp.A.cordata, Lonicera japonica and Quercus virginiana is above 90%.;the survival rate of Populus×euramerican cv. Lulin 1, Populus×euramerican cv. L35 and Populus×euramerican cv. Nanlin 895 is above 90%; the survival rate of Taxodium distichum is above 70%; the survival rate of Zelkova serrata is 50%; the worst survival rate is Celtis sinensis Pers. The salt injury symptoms barely appeared in Alnus spp.A.cordata, Lonicera japonica and Quercus virginiana; the salt injury symptoms a few appeared in Populus×euramerican cv. Lulin 1, Populus×euramerican cv. L35 and Populus×euramerican cv. Nanlin 895; the salt damage index of Zelkova serrata is 47.5%; the salt damage index of Celtis sinensis Pers is 87.5%, some of Celtis sinensis Pers have dead.(2)By the method of subordinate function,we choose the biomass, the root/shoot ratio, the proline contents, the soluble sugar contents, the membrance permeability, the net photosynthetic rate, the stomata conductance, the intercellular CO2 contentration, the transpiration rate and organic mineral elements evaluate the salt tolerance. The salt tolerance of 10 tree species was determined comprehensively, these are, Lonicera japonica> Populus×euramerican cv. Lulin 1> Populus×euramerican cv. L35> Alnus spp.A.cordata> Populus×euramerican cv. Nanlin 895> Quercus virginiana> Taxodium distichum >Zelkova serrata> Celtis sinensis Pers in no salt soil.(3) Quercus virginiana and Taxodium distichum appeared lower the survival rate and the salt damage index in saline soil than no salt soil, the survival rate of Quercus virginiana is 30% in saline soil, the survival rate of Taxodium distichum is 40% in saline soil. The membrance permeability and Na+ of seedings in saline soil is higher than the membrance permeability and Na+ of seedings in no salt soil. The biomass, the net photosynthetic rate, the transpiration rate, Ca2+ and Mg2+ in saline soil is lower than the biomass, the net photosynthetic rate, the transpiration rate, Ca2+ and Mg2+ in no salt soil. In general Lonicera japonica,Populus×euramerican cv. Lulin 1, Populus×euramerican cv. L35,Alnus spp.A.cordata, Populus×euramerican cv. Nanlin 895 and Elaeagnus angustifolia is suitably planted in saline soil.