《植物生理学报》 2015, 51(10): 1649-1657

盐胁迫下不同钾素水平对海滨锦葵生长和光合作用的影响

董轲, 许亚萍, 崔冰, 王梦雨, 秦荣凤, 唐亦俐, 范海^*

山东师范大学逆境植物重点实验室, 济南250014

通信作者：范；E-mail: biofanhai@163.com；Tel: 0531-86182568

摘　要：

为探讨钾对盐胁迫下海滨锦葵生长的影响及盐胁迫下的最适钾素浓度, 将在1、3、6、9、12、15 mmol•L^-1钾素水平下培养的海滨锦葵幼苗分别用0、100和200 mmol•L^-1的NaCl处理。培养一段时间后测定其生长状况、光合气体交换、叶绿素a荧光动力学、离子积累及伤害指标, 结果显示: 随着NaCl胁迫的加剧, 海滨锦葵Na⁺含量明显上升, K⁺含量下降, 海滨锦葵幼苗在100 mmol•L^-1 NaCl下其生长受到抑制, 200 mmol•L^-1 NaCl处理下抑制更加显著。随着钾素浓度的提高, Na⁺/K⁺比降低, 海滨锦葵幼苗的株高、干鲜重和单株总叶面积明显变大, 净光合效率(P_n)、蒸腾速率(T_r)、气孔导度(G_s)明显升高, 最大光化学效率(F_v/F_m)、实际光化学效率(Φ_PSII)也明显增大。研究同时发现: 非盐胁迫下, 海滨锦葵生长的最适钾素水平为6~9 mmol•L^-1, 而在NaCl胁迫下最适钾素水平为9~12 mmol•L^-1。实验结果表明, 盐胁迫增加了海滨锦葵对钾素的需求, 适当增加钾素浓度可以缓解盐胁迫对海滨锦葵造成的伤害。

关键词：海滨锦葵; 盐胁迫; 钾素; 生长; 光合作用

收稿：2015-07-01   修定：2015-09-21

资助：山东省自主创新及成果转化专项课题(2015ZDJS03002)。

Effects of Different Potassium Levels on the Growth and Photosynthesis of Kostelezkya Virginica under Salt Stress

DONG Ke, XU Ya-Ping, CUI Bing, WANG Meng-Yu, QIN Rong-Feng, TANG Yi-Li, FAN Hai^*

Key Laboratory of Plant Stress Research, Shandong Normal University, Jinan 250014, China

Corresponding author: FAN Hai; E-mail: biofanhai@163.com; Tel: 0531-86182568

Abstract:

In order to investigate the effect of potassium on the growth of Kostelezkya virginica under salt stress and the optimal potassium level, K. virginica seedlings were supplied with 1, 3, 6, 9, 12 and 15 mmol•L^-1 potassium fertilizers under 0, 100 and 200 mmol•L^-1 NaCl conditions. Then the parameters of the seedlings including growth conditions, photosynthetic gas exchange, chlorophyll a fluorescence dynamics, ion accumulation and plant injury indices were determined. Results show that the growth of the seedlings was inhibited by 100 mmol•L^-1 NaCl and, even more seriously, by 200 mmol•L^-1 NaCl. With the increase of NaCl stress, Na⁺ content increased and K⁺ content went down obviously. Furthermore, with the increase of potassium level, Na⁺/K⁺ ratio decreased, meanwhile the plant height, dry and wet weights, plant total leaf area, the net photosynthetic rate (P_n), transpiration rate (T_r), stomatal conductance (G_s), maximal photochemical efficiency (F_v/F_m) and actual photochemical efficiency (Φ_PSII) all increased obviously. The study also found that the optimal potassium level for K. virginica was 6–9 mmol•L^-1 under control, while 9–12 mmol•L^-1 under NaCl stress, suggesting that the demand of K. virginica for potassium increases under salt stress and appropriate increase of potassium concentration can alleviate salt injury.

Key words: Kosteletzkya virginica; salt stress; potassium; growth; photosynthesis