臭氧胁迫对冬小麦光响应能力及PSⅡ光能吸收与利用的影响

为准确评价O3胁迫对冬小麦光响应能力和PSⅡ光能吸收、分配与利用的影响，通过OTC设置了活性碳过滤空气(CF，4—28 nL/L)、不通风(5H，15—68 nL/L)、环境空气(NF，7—78 nL/L)、100nL/L O3 (CF100，96—108 nL/L)和150nL/L O3 (CF150，145—160nL/L) 等5种O3熏蒸处理，用IMAGING-PAM测量了冬小麦（丰抗13）扬花期的Fo、Fm及自然光下的快速光曲线。结果表明，O3胁迫显著降低了冬小麦PSⅡ的最大量子效率(Fv/Fm)、最大光合速率(Pm)、半饱和光强(Pm/α)、吸光系数(IA)、调节性热耗散的量子产额(Y(NPQ))和非光化学淬灭系数(NPQ)，显著提高了冬小麦的初始光能利用效率(α)、非调节性热耗散的量子产额(Y(NO))和PSⅡ吸收光能的日累计损失（Daily ∑Y(NO)+ Daily ∑Y(NPQ)）；CF处理显著提高了冬小麦的Pm、α、Y(NPQ)、NPQ及PSⅡ日累计利用的光能（Daily ∑Y(Ⅱ)）；当其余4组的Y(NPQ)和NPQ趋于饱和时，NF仍在以较快的速率上升。O3胁迫显著降低了冬小麦吸收、利用光能的能力和光保护能力，改变了PSⅡ吸收光能的分配结构，提高了冬小麦对光强变化的敏感性，加剧了光抑制，致使冬小麦受到O3和过剩光能的双重伤害；CF处理下冬小麦的光合能力和光保护能力显著提高，但对强光的潜在耐受能力低于NF；固城的空气质量已对冬小麦造成一定影响，极可能导致产量损失。

Ozone stress on light response capacity and on the utilization of PS Ⅱ absorbed light energy of winter-wheat

Nowadays,ozone is considered to be the severest gaseous pollutant for plant productivity in many parts of the world,not only because of its heavy phytotoxicity but because of its concentration that had been increasing over the last century.Wheat is one of the most ozone-sensitive crops,with sensitivity differing between cultivars and cultivating modes of the same cultivar.Photosynthesis serves as a determinant of crop yield and plays a central role in botanical physiology,with the functional state as an ide...