盐胁迫下杨树根际系统盐分离子分布特性

Distribution of K^+, Na^+, Ca^(2+) and Mg^(2+) in poplar rhizosphere system under NaCl stress

在温室条件下,采用盆栽根箱培养的方法研究盐胁迫下I 69杨(PopulusdeltoidesBartr.cv.'Lux')和NL 1381杨〔PopulusdeltoidesBartr.cv.'Lux'×P.euramericana(Dode)GeninierCL'I 45 51'〕根际、非根际土壤盐分分布特征。盐处理浓度共设3个水平:CK(NaCl0g kg)、处理A(NaCl1g kg)和处理B(NaCl2g kg),采用完全随机设计。结果表明,2个杨树无性系根际水溶性K+亏缺,水溶性Na+、Ca2+和Mg2+富集。K+的亏缺率及Na+的富集率随NaCl处理浓度的增大而减小,Ca2+和Mg2+的富集率在非盐渍条件下最低,处理A达最高,处理B较处理A略有下降。在盐胁迫下,无性系NL 1381杨根际土壤Na+的浓度和电导率均低于无性系I 69杨,可以有效减轻盐分对根系的渗透胁迫,相对而言具有较强的抗盐性。

The rhizobox experiments were randomized completely designed, with application of NaCl to furnish 0, 1 and 2 g/kg soil, to study the distribution of K\+\{+\}, Na\+\{+\}, Ca\+\{2+\} and Mg\+\{2+\} in poplar rhizosphere system under NaCl stress in greenhouse. Two poplar clones, I\|69 (\%Populus deltoides \%Bartr. cv. 'Lux') and NL\|1381 〔\%Populus deltoides \%Bartr. cv. 'Lux'×\%P. euramericana \%(Dode) Geninier CL 'I\|45/51'〕, were chosen for the study. The results indicated that the water\|soluble K\+\{+\} of soils in rhizosphere of two poplar clones was lower than those in non\|rhizosphere, but Na\+\{+\}, Ca\+\{2+\} and Mg\+\{2+\} were accumulated obviously in rhizosphere under three NaCl treatments. The depleting ratio of K\+\{+\} and accumulating ratio of Na\+\{+\} for each system of clones decreased with the increase of NaCl concentration, but the accumulating ratios of Ca\+\{2+\} and Mg\+\{2+\} under treatment B (NaCl 2 g/kg) were obviously higher than under control, but slightly lower than those of treatment A (NaCl 1 g/kg). Na\+\{+\} concentration and electrical conductivity in rhizosphere of clone NL\|1381 were lower in comparison with clone I\|69 under NaCl treatments, and therefore reducing the salt stress. It is probably that clone NL\|1381 is stronger in tolerating salt stress.