Air Pollution Laboratory (APL), Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, P. O. Box 80216, Jeddah 21589, Saudi Arabia.
Air Pollution Laboratory (APL), Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, P. O. Box 80216, Jeddah 21589, Saudi Arabia; Department of Botany, Faculty of Science, Alexandria University, 21526 El Shatby, Alexandria, Egypt.
Sci Total Environ. 2014 Nov 1;497-498:585-593. doi: 10.1016/j.scitotenv.2014.06.047. Epub 2014 Aug 27.
Egyptian pea cultivars (Pisum sativum L. cultivars Little Marvel, Perfection and Victory) grown in open-top chambers were exposed to either charcoal-filtered (FA) or non-filtered air (NF) for five consecutive years (2009-2013) at a rural site in northern Egypt. Net photosynthetic rates (PN), stomatal conductance (gs), intercellular CO2 (Ci) and chlorophyll fluorescence were measured. Ozone (O3) was found to be the most prevalent pollutant common at the rural site and is suspected to be involved in the alteration of the physiological parameters measured in the present investigation. PN of different cultivars were found to respond similarly; decreases of 23, 29 and 39% were observed in the cultivars Perfection, Little Marvel and Victory, respectively (averaged over the five years) due to ambient O3. The maximum impairment in PN was recorded in the cultivar Victory (46%) in 2013 when the highest O3 levels were recorded (90 nL L(-1)). The average stomatal conductance decreased by 20 and 18% in the cultivars Little Marvel and Perfection, respectively, while the average stomatal conductance increased on average by 27% in the cultivar Victory. A significant correlation was found between PN and Ci, indicating the importance of non-stomatal limitations of photosynthesis, especially in the cultivar Victory. The PN vs. Ci curves were fitted to a non-rectangular hyperbolic model. The actual quantum yield (ΦPSII) and photochemical quenching coefficient (qP) were significantly decreased in the leaves of plants exposed to NF air. Non-photochemical quenching (NPQ) was increased in all cultivars. Exposure to NF air caused reductions in chlorophyll (Chl a) of 19, 16 and 30% in the Little Marvel, Perfection and Victory cultivars, respectively.
在埃及北部的一个农村地区，连续五年（2009-2013 年），将开放顶室中种植的埃及豌豆品种（Pisum sativum L. 品种小奇迹、完美和胜利）暴露于经过活性炭过滤的（FA）或未经过滤的空气（NF）中。测量了净光合速率（PN）、气孔导度（gs）、胞间 CO2（Ci）和叶绿素荧光。发现臭氧（O3）是农村地区最普遍的污染物，并且怀疑它参与了本研究中测量的生理参数的改变。不同品种的 PN 表现出相似的反应；在品种完美、小奇迹和胜利中，分别观察到 23%、29%和 39%的 PN 减少（五年平均值），这是由于环境 O3 造成的。在 2013 年 O3 水平最高时，品种胜利的 PN 最大损害（46%）。平均气孔导度在小奇迹和完美品种中分别降低了 20%和 18%，而在胜利品种中平均增加了 27%。发现 PN 与 Ci 之间存在显著相关性，表明光合作用的非气孔限制的重要性，特别是在胜利品种中。PN 与 Ci 的关系曲线拟合为非矩形双曲线模型。在暴露于 NF 空气的叶片中，实际量子产量（ΦPSII）和光化学猝灭系数（qP）显著降低。所有品种的非光化学猝灭（NPQ）均增加。暴露于 NF 空气导致小奇迹、完美和胜利品种的叶绿素（Chl a）分别减少 19%、16%和 30%。
