摘要
对生长在蛭石中8周龄的星星草(Puccinellia tenuiflora(Criseb.)Scribn.et Merr.)用 12.5—800mmol/L 的中性盐 NaCl或碱性盐 Na_2CO_3进行胁迫处理,测定植物日相对生长率等胁变指标。结果表明星星草的抗盐性高于抗碱性,可耐受的最高浓度分别为:中性盐NaCl 600 mmol/L、碱性盐 Na_2CO_3 200mmol/L_o NaCl胁迫下,随胁强增高,脯氨酸明显积累,柠檬酸含量则逐渐下降;Na_2CO_3胁迫下,脯氨酸仅稍有积累而柠檬酸含量却急剧升高。两种胁迫下都表现出:随胁强增大,Na^+含量明显上升,K^+含量下降。但是,NaCl胁迫对K^+含量影响不大,而Na_2CO_3胁迫则导致根及茎叶中的K^+含量明显下降。诸胁变指标中唯有叶片电解质外渗率对两种胁迫来说变化特点相似。
Eight-week-old plants of Puccinellia lenuiflora (Griseb.) Scribn. et Merr. growing in pots filled with vermiculite were stressed by treating with 12.5-800 mmol/L solutions of neutral salt(NaCl) or basic salt(Na_2CO_3). Strain indexes such as relative growth rate etc. were deter- mined. There was a significant difference betwen the two kinds of stresses. Maximum stress value that P. tenuiflora plants can tolerate is 60 mmol/L for the neutral salt and 200 mmol/L for the basic salt Na_2CO_3. Under NaCl-stress, great amount of proline accumulated, and citric acid content gradually decreased. But under Na_2CO_2-stress, proline content did not raise too much and citric acid content obviously increased with the increasing stress value. Under both stress conditions, Na^+ content increased and K^+ content decreased with the increasing stress value, but the effect of NaCl-stress on K^+ content in roots and shoots was much less than that of Na_2CO_3-stress. In both stresses, the elevation of electrolyte leakage rate of leaf orchestrated with the change of stress value. This finding represented the only similarity among the strain indexes determined in both stresses.
基金
国家自然科学基金
关键词
星星草
盐胁迫
碱胁迫
Puccinellia tenuiflora
Saline stress
Alkaline stress
Strain
