Gas exchange, chlorophyll fluorescence, and osmotic adjustment in two mango cultivars under drought stress
Gas exchange, chlorophyll fluorescence, and osmotic adjustment in two mango cultivars under drought stress
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DOI：
10.1007/s11738-008-0179-x
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发表时间：
2008-11-01
影响因子：
2.6
通讯作者：
Cao, Kun-Fang
中科院分区：
文献类型：
--
作者：
Elsheery, Nabil I.;Cao, Kun-Fang
研究了两个芒果品种（Mangifera indica L. var.）幼苗截水15 d和复水化对光合气体交换、叶绿素荧光、色素、主要渗透物和丙二醛（MDA）含量的响应。“掐死阿南德”和瓦尔。在50%日照和全日照条件下对“Khieo Sawoei”进行了研究。对这两个品种来说，截水导致叶片相对含水量、净光合作用（P-n）、气孔导度（g(s)）逐渐降低，叶黄素循环色素的转化率（通过叶片光谱反射率指数（Delta PRI）、类胡萝卜素与叶绿素比值、非光化学猝灭（NPQ）、丙二醛（MDA）和相容溶质（总可溶性糖和脯氨酸）的含量估算）增加。水分胁迫的影响在充分日照条件下比50%日照条件下更为明显。在两种光照条件下，两个品种在黎明测量的最大光化学效率在处理期间相当稳定。在两种光照条件下，水分胁迫对“Choke Anand”品种光合作用的抑制作用均小于“Khieo Sawoei”品种。再水化后，“窒息阿南德”的恢复速度相对快于“乔夫佐威”。在50%和全光照条件下，两个品种在5 d后光化学完全恢复，但光合作用没有完全恢复，从气体交换率可以看出。由于NPQ、δ PRI和渗透调节较低，“Khieo Sawoei”对干旱的耐受性低于“Choke Anand”。我们的研究进一步表明，部分遮荫（如50%的日照）显著减轻了干旱胁迫对芒果品种的有害影响，但事实上，部分遮荫下生长的幼苗气孔对水分亏缺的反应比全光照下更强烈。
The responses of photosynthetic gas exchange, chlorophyll fluorescence, content of pigments, main osmolytes, and malondialdehyde (MDA) to water-withholding for 15 days and re-hydration in seedlings of two mango cultivars (Mangifera indica L. var. "Choke Anand' and var. "Khieo Sawoei") under 50% sunlight and full sunlight were investigated. For both cultivars, the water-witholding resulted in progressively decreases in leaf relative water content, net photosynthesis (P-n), stomatal conductance (g(s)), and increases in the conversion of xanthophyll cycle pigments estimated by an index of leaf spectral reflectance (Delta PRI), carotenoid to chlorophyll ratio, non-photochemical quenching (NPQ), the contents of malondialdehyde (MDA) and compatible solutes (total soluble sugar and proline). The effect of the water stress was more pronounced in full sunlight than 50% sunlight. The maximum photochemistry efficiency measured at dawn was fairly constant during the period of the treatment for both cultivars under both light regimes. The water stress caused less pronounced inhibition of photosynthesis in "Choke Anand" than in "Khieo Sawoei" cultivar under both light regimes. After re-hydration, the recovery was relatively quicker in "Choke Anand" than in "Khieo Sawoei" cultivar. Both cultivars in both 50% and full sunlight showed complete recovery in photochemistry after 5 days of re-watering but photosynthesis did not show a complete recovery as indicated by gas exchange rates. As the results of lower NPQ, Delta PRI and osmotic adjustment in the cultivar "Khieo Sawoei" compared to the cultivar "Choke Anand", the former cultivar was less tolerant to drought than the latter. Our study further showed that partial shading (e.g., 50% of sunlight) significantly alleviated the harmful effect of drought stress on mango cultivars but in fact stomata of seedlings grown in partial shade was more responsive to water deficit than in full light.