盐胁迫下树种幼苗生长及其耐盐性

采用盆栽方法,以11个树种实生幼苗为材料,用不同浓度(0、3、5、8 g·kg-1和10 g·kg-1)NaCl溶液进行1次性浇灌处理,对盐胁迫下各树种的形态表现、生长及耐盐性进行了研究,结果表明:(1)当盐含量达到8 g·kg-1时,欧洲荚蒾、甜桦和光叶漆植株死亡,当含量增加到10 g·kg-1时,沃氏金链花植株死亡,其它各存活树种也均出现不同程度的盐害症状;(2)盐胁迫后,各树种的苗高生长量下降、生物量累积减少,且随着处理浓度的增加均呈下降趋势,其中榆桔、甜桦和光叶漆的降幅最大;(3)盐处理后,各树种的根冠比值增大,其中盐胁迫对光叶漆、银水牛果和沃氏金链花有显著影响(p<0.05);(4)综合分析各树种的生长和形态表现,认为日本丁香、银水牛果、三裂叶漆和豆梨具有高度耐盐性,沃氏金链花、金雀儿、鹰爪豆和榆桔具有中高度耐盐性,而欧洲荚蒾、甜桦和光叶漆具有中度耐盐性.

Seedling growth and salt tolerance of tree species under NaCl stress

The growth and morphological characteristics were investigated from seedlings of 11 tree species. The seedlings were cultivated in pots that were treated with sodium chloride (NaCl) solutions with concentrations of 0, 3, 5, 8 g?kg-1 and 10 g?kg-1 of soil dry weight. The seedlings of Viburnum opulus, Betula lenta and Rhus glabra were dead at the treatment level of 8 g?kg-1 soil dry weight, and those of Laburnum watereri were dead at 10 g?kg-1 soil dry weight, while other survivable seedlings were salt-damaged to different degrees. The height and biomass accumulation of salt-stressed seedlings decreased as the salt concentration increased, this was especially evident for the seedlings of Ptelea trifoliate, Betula lenta and Rhus glabra. Under the salt stress, the root/shoot dry weight ratio increased almost for all species, among which the ratios of Rhus glabra, Shepherdia argentea, and Laburnum watereri were significantly different from that of the controls (p<0.05). Based on the analysis of growth and morphological appearance the results indicate that, Syringa japonica, Shepherdia argentea, Rhus trilobata, and Pyrus calleryana are highly salt-tolerant, while Laburnum watereri, Cytisus scoparius, and Spartium junceum are intermediately salt-tolerant, and Viburnum opulus, Betula lenta, and Rhus glabra are moderately salt-tolerant.