碱性盐胁迫对燕麦矿质离子吸收与分配的影响

Effects of Alkali Salt Stress on Mineral Ion Absorption and Distribution of Oats

为探讨燕麦耐碱性与矿质离子的关系,通过盆栽试验,将碱性盐Na2CO3、NaHCO3按摩尔比1∶1混合设置不同浓度(0、50和100mmol·L-1)胁迫处理,分析燕麦耐碱性品种vao-9和碱敏感性品种白燕5号根、茎、叶对Na+、K+、Ca2+、Mg2+、Fe2+、Cu2+、Zn2+的吸收及分配规律。结果表明,碱性盐胁迫下2个品种根、茎、叶中Na+含量增加,K+、Cu2+含量下降;Ca2+、Mg2+含量在根中增加,在茎、叶中下降,Fe2+、Zn2+含量在不同胁迫程度下和不同器官中变化不同。与白燕5号相比,vao-9吸收的Na+总量较低,K+、Ca2+、Cu2+总量较高,Mg2+、Fe2+、Zn2+总量变化不大。在胁迫浓度达到100mmol·L-1时,vao-9茎中截留Na+,叶片中较K+、Ca2+、Mg2+、Fe2+、Cu2+和Zn2+分配较多,而白燕5号叶片中积累Na+较多,茎中积累K+较多,根中积累Ca2+、Mg2+、Fe2+、Cu2+、Zn2+较多,从而使碱性盐胁迫下vao-9较白燕5号叶片中保持的Na+/K+、Na+/Ca2+和Na+/Mg2+低。可见,在高浓度碱性盐胁迫下vao-9茎中区域化Na+,选择吸收K+、Ca2+、Cu2+,并在叶片中分配较多的矿质离子来保持燕麦体内离子平衡,以适应盐碱胁迫。

In order to explore the relationship between mineral ion and alkali tolerance of oats, the absorption and distribution characteristics of Na^＋ , K^＋ , Ca^2＋ , Mg^2＋ , Fe^2＋ , Cu^2＋ and Zn^2＋ in roots, stems, leaves of different varieties oats （alkali-tolerant vao-9, alkali-sensitive Baiyan 5） under alkali stress （molar ratio of Na2CO3, NaHCO3 = 1 1） were studied in potted experiment. Result showed that the Na^＋ content was increased, while K^＋ and Cu^2＋ contents were decreased under alkali stress the contents of Ca^2＋ , Mg^2＋ were increased in roots and were decreased in shoots; while Fe^2＋ , Zn^2＋ contents were different in different stress treatments and different organs of two varieties. Na^＋ absorbed in vao-9 were less than that in Baiyan 5, and K^＋ , Ca^2＋ , Cu^2＋ absorbed in vao-9 were more than that in Baiyan 5, there were little difference in Mg^2＋ , Fe^2＋ , Zn^2＋ between two varieties, vao-9 could store Na^＋ in stems and distribute high contents of K^＋ , Ca^2＋ , Mg^2＋ , Fe^2＋ , Cu^2＋ , and Zn2＋ in leaves under 100 mmol. L^-1 concentration, while Baiyan 5 accumulate the Na^＋ in leaves, K^＋ in stems and Ca^2＋ , Mg^2＋ , Fe^2＋ , Cu^2＋ , Zn2＋ in roots, which led to lower contents of Na^＋/ K^＋ , Na^＋/Ca^2＋ ,Na^＋/ Mg^2＋ in vao-9 that in Baiyan 5. It was concluded that vao-9 could keep ions balance to adapt to alkali stress through compartmentalizing Na^＋ in stem, selective absorption of K^＋ , Ca^2＋ , Cu^2＋ and distributing high mineral ion in leaves under high alkali stress.