Differential responses in two varieties of winter wheat to elevated ozone concentration under fully open-air field conditions
Differential responses in two varieties of winter wheat to elevated ozone concentration under fully open-air field conditions
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DOI：
10.1111/j.1365-2486.2010.02184.x
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发表时间：
2011-01-01
影响因子：
11.6
通讯作者：
Ort, Donald R.
中科院分区：
文献类型：
--
作者：
Feng, Zhaozhong;Pang, Jing;Ort, Donald R.
两个现代冬小麦品种[扬麦16号(Y16)和扬富麦2号(Y2)]。在全露天条件下，对物候基本一致的中国进行了臭氧浓度升高(E-O-3)对光合作用相关生理特性的影响。植株从分蘖开始到最终收获，E-O-3为环境臭氧浓度(A-O-3)的127%。在旗叶发育过程中，对3个重复小区进行了色素、气体交换速率、叶绿素a荧光和脂类氧化的测定。在品种Y2中，E-O-3显著加速了叶片的衰老，表现为脂质氧化增加，色素含量和光合作用速率下降更快。较低的光合速率主要是由于非气孔因素，如较低的最大羧化能力、电子传递速率和光能分配。相比之下，在Y16品种中，E-O-3的作用仅在旗叶衰老的最后阶段观察到。由于两个品种在衰老前物候基本相同，叶片气孔导度非常相似，E-O-3对品种Y2的影响比对Y16的影响更大，不能用臭氧吸收的差异来解释。我们的发现将有助于科学家在东亚和南亚地区选择耐O-3小麦品种以抵御上升的O-3。
Two modern cultivars [Yangmai16 (Y16) and Yangfumai 2 (Y2)] of winter wheat (Triticum aestivum L.) with almost identical phenology were investigated to determine the impacts of elevated ozone concentration (E-O-3) on physiological characters related to photosynthesis under fully open-air field conditions in China. The plants were exposed from the initiation of tillering to final harvest, with E-O-3 of 127% of the ambient ozone concentration (A-O-3). Measurements of pigments, gas exchange rates, chlorophyll a fluorescence and lipid oxidation were made in three replicated plots throughout flag leaf development. In cultivar Y2, E-O-3 significantly accelerated leaf senescence, as indicated by increased lipid oxidation as well as faster declines in pigment amounts and photosynthetic rates. The lower photosynthetic rates were mainly due to nonstomatal factors, e.g. lower maximum carboxylation capacity, electron transport rates and light energy distribution. In cultivar Y16, by contrast, the effects of E-O-3 were observed only at the very last stage of flag leaf ageing. Since the two cultivars had almost identical phenology and very similar leaf stomatal conductance before senescence, the greater impacts of E-O-3 on cultivars Y2 than Y16 cannot be explained by differential ozone uptake. Our findings will be useful for scientists to select O-3-tolerant wheat cultivars against the rising surface [O-3] in East and South Asia.