高大气CO_2浓度下遮阴对小麦叶片气孔特性及光合特性的影响

Effects of Shading on Stomatal and Photosynthetic Characteristics of Spring Wheat Under Elevated Atmospheric CO_2 Concentration

以高大气CO_2浓度和遮阴为处理手段,研究高大气CO_2浓度和遮阴对小麦叶片光合生理的影响。结果表明,与全光照相比,遮阴使小麦叶片的气孔长度增加了22.93%和10.23%,而气孔宽度减小了30.00%和30.22%,气孔面积降低了17.99%和18.11%,周长增加了16.80%和6.85%,气孔密度降低了6.61%和23.78%,气孔指数降低了5.99%和14.23%。与正常大气CO_2浓度相比,高大气CO_2浓度使小麦叶片的气孔面积增加了1.91%和1.95%,使全光照处理的小麦叶片的气孔密度降低了14.33%;使遮阴处理的小麦叶片的气孔密度增加了5.00%。与全光照相比,遮阴使小麦叶片的气孔导度和蒸腾速率降低了56.11%、53.21%和40.57%、49.27%,而光合速率没有得到提高,这可能是小麦叶片对高大气CO_2浓度发生了"光适应"。与正常大气CO_2浓度相比,高大气CO_2浓度降低了小麦叶片的气孔导度。小麦叶片的气孔长度和宽度与光合速率有显著相关性。

Effects of shading and elevated atmospheric CO_2 concentration on leaf photosynthetic physiology are investigated using shading and elevated atmospheric CO_2 concentration treatments. The result shows that compared with normal sunlight condition,shading treatments increased stomata length by 22.93% and 10.23%,decreased stomata width by 30.00% and 30.22%,decreased stomatal area by 17.99% and 18.11%,increased circumference by 16.80% and 6.85%,decreased stomata density by 6.61% and23.78%,and decreased stomatal index by 5.99% and 14.23%,under normal and elevated atmospheric CO_2 concentration,respectively. Compared with normal atmospheric CO_2 concentration,elevated atmospheric CO_2 concentration increased stomatal area by1.91% and 1.95%,decreased stomata density by 14.33% under sunlight condition while increased by 5.00% with shading treatment.Compared with sunlight condition,shading decreased stomatal conductance by 56.11% and 53.21% and transpiration rate by 40.57%and 49.27% under normal and elevated CO_2 concentration,respectively. However,the treatments have no effects on photosynthetic rate,which is probably due to the occurrence of ＂light adaptation＂under elevated CO_2 concentration. Compared with normal atmospheric CO_2 concentration,elevated CO_2 concentration decreased stomatal conductance of wheat. Leaf pore length and blades width of wheat are significantly correlated with the rate of photosynthesis.