NaCl胁迫下栽培型番茄Na+、K+吸收、分配和转运特性

【目的】明确盐分胁迫下栽培型番茄离子吸收、分配和转运特性。【方法】以栽培番茄为试材,以NaCl溶液为盐分胁迫条件,通过苗期耐盐性鉴定,采用原子吸收光谱法测定不同耐盐性番茄品种体内离子含量,对盐分胁迫下番茄体内离子积累、分布和转运机制进行系统分析。【结果】番茄对Na+的吸收随盐分处理浓度和时间的增加而增加,在各器官的积累量顺序为根＞茎＞叶。对于较耐盐品种,Na+在体内的积累总量低于盐敏感品种。盐分胁迫后,番茄叶片、茎和根系中Na+/K+比均随NaCl浓度的升高而升高。耐盐品种的Na+/K+比低于盐敏感品种。离子在体内的区域化分布情况是,较耐盐品种的Na+在根茎中的分配比例较高,盐敏感品种趋向于向叶片分配。K+在较耐盐品种的分布集中于叶片。在盐胁迫初期,盐分处理浓度超过200 mmol•L-1时,番茄植株对K+向地上部的选择运输性随着胁迫时间的延长呈现出下降的趋势。低于200 mmol•L-1时,表现出很好的选择运输性,耐盐品种的Sk/Na(运输)高于盐敏感品种,根系表现出更强的向地上部运输K+的能力。【结论】盐分胁迫下,叶片中较低的Na+含量和更强的向地上部运输K+的能力是番茄耐盐性的重要特征。

Study on the Characteristics of Absorption, Distribution and Selective Transport of Na~+ and K~+ in Tomato Plants Under Salt Stress

Objective] This experiment was carried out to elucidate the effects of salt stress on absorption, distribution and selective transport of Na~+ and K~+ in tomato plants. Method] The absorption, distribution and selective transport of Na~+ and K~+in tomato plants under salt stress were analyzed by atomic absorption spectrometry. Result] The results showed that with salt stress concentration and time increased, Na+ absorption of tomatoes increased, the fundamental order of accumulation in various organs was root>stem>leaf. The total accumulation of Na+ in salt-tolerant eultivar was lower than that in salt-sensitive one. Under salt stress, Na~+ contents in tomato leaves, stems and roots were increased with the increase of NaCI concentration. Na~+ contents in salt-tolerant cultivar were lower than that in salt-sensitive one. From the regional distribution of ions in the tomato plant, there was a higher Na+ proportion in rhizomes of salt-tolerant cultivar; the distribution of potassium was more focused in leaves. The salt-sensitive cultivar tended to allocate Na* to the leaves. Under early salt stress, the salt concentration was 200 mmol·L~(-1) and more. The choice of K~+ transport in tomato plants to shoot with the stress showed a downward trend. Below 200 mmol·L~(-1) showed a good alternative transportation, S_(k/Na) (transport) of salt-tolerant cultivar were higher than that of salt-sensitive cultivar. Root of salt-tolerant cultivar showed a greater K~+ transport ability. Conclusion] The lower Na~+ content in leaves and better alternative transportation of K~+ under salt stress are the most important characteristics of salt tolerant tomato varieties.