<正>在温室条件下,采用盆栽根箱培养的方法研究了盐胁迫下土壤-杨树系统中盐分离子的运移与分布特征。结果表明,各处理下杨树根际土壤中K+出现亏缺,Na+、Ca2+、Mg2+均出现富集。在低盐胁迫下,杨树根系优先选择吸收K+、Ca2+和Mg2+,而对Na+的选择性有所减弱;两个杨树无性系能在根中积累较多的阳离子,同时I 69杨对Ca2+,NL 1381杨对K+、Ca2+和Mg2+向地上部分运输的选择性也有所增强,但抑制Na+向地上部分的运输,以减缓Na+对地上部分生长的胁迫。

The characteristics of salinity ions distribution in soiltree system change under salt stress because many physiological activities of trees are changed,which influences the absorption of water and selectiveabsorption of ions by roots.In this project,the rhizoboxes experiments were randomized completely designed,with application of NaCl to furnish 0,1,and 2 g/kg NaCl,to study the transportation and distribution of K+,Na+,Ca2+,and Mg2+ in soilpoplar systems under NaCl stress in greenhouse.The main results indicated that the watersoluble K+ in rhizosphere were lower than that in nonrhizosphere,but Na+,Ca2+,and Mg2+ were accumulated in rhizosphere under three NaCl treatments.The two poplar clones,I69(Populus deltoides Bartr.cv.’Lux’) and NL1381(the highbred of I69 and P.euramericana(Dode) Geninier CL ’E45/51’),could absorb K+,Ca2+,and Mg2+ more selectively than Na+ under 1 g/kg NaCl treatment,and improve the selective transportation of Ca2+(clone I69) or K+,Ca2+,and Mg2+(clone NL1381)to the aerial parts.