Abstract: 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 (P<0.05). The K⁺/Na⁺ ratios in different organs were ranked as leaves>stems>roots. K⁺ and Na⁺ absorption of selectivity ratios (AS_K,Na) in roots increased significantly with the degree of soil saline-alkali increasing. Transportation of selectivity ratio (TS_K,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, TS_K,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.

Key words: Helianthus tuberosus, Salinity stress, Na⁺, K⁺, Ion distribution

摘要： 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(P<0.05),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AS_K,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TS_K,Na升高,而在重度胁迫下则下降。同一盐碱程度胁迫下,叶片TS_K,Na>茎TS_K,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。

关键词: 菊芋, 盐碱胁迫, Na⁺, K⁺, 离子分布