Effects of different saline-alkali grasslands on ion distribution of Helianthus tuberosus | 不同盐碱化草地对菊芋离子分布的影响

chinois. 以轻度、中度和重度盐碱化草地上种植的菊芋（Helianthus tuberosus L.）为试验材料，通过测定其不同生育期的离子分布，以期了解和揭示菊芋在不同盐碱胁迫下K+，Na+变化机制。结果表明：随土壤盐度的增加，菊芋植株Na+含量显著增加, K+含量和K+/Na+值显著下降（P0.05），不同器官K+/Na+值的变化顺序为：叶片茎根系。随土壤盐碱度的增加，根系K+，Na+的选择性吸收比率ASK，Na升高；中度盐碱胁迫下菊芋现蕾期茎和叶片的选择性运输比率TSK，Na升高，而在重度胁迫下则下降。同一盐碱程度胁迫下，叶片TSK，Na茎TSK，Na，地上部K+，Ca2+，Mg2+含量和K+/Na+值大于地下部，而Na+含量小于地下部；不同生育期相比，在现蕾期菊芋中Na+含量较低，K+下降幅度小，K+/Na+值最高。

anglais. In order to explore K+ and Na+ contents of Helianthus tuberosus under different salinity stress, Helianthus tuberosus was planted in three plots classified as light, moderate, and heavy in saline-alkali grasslands.Ion distributions of Helianthus tuberosus in different growing periods were determined. Results showed that Na+ contents of whole plants increased significantly, and both K+ contents and K+ /Na+ ratio decreased significantly with the degree of soil saline-alkali increasing (P0.05). The K+ /Na+ ratios in different organs were ranked as leavesstemsroots. K+ and Na+ absorption of selectivity ratios (ASK, Na) in roots increased significantly with the degree of soil saline-alkali increasing. Transportation of selectivity ratio (TSK, Na) in stems and leaves of Helianthus tuberosus increased under moderate salinity stress in bud stage, but decreased under heavy salinity stress. In the same salinity stress levels, TSK, Na were higher in leaves than in stems, while the contents of K+, Ca2+, Mg2+ and K+ /Na+ were higher in aboveground parts than in underground parts. Na+ contents were higher in underground parts than in aboveground parts. Na+ content was the lowest, K+ /Na+ was the highest, as K+ contents decreased slightly in bud stages compared with other growing stages.