| 开放式臭氧浓度升高对2个冬小麦品种光合损伤的研究 |
| 摘要点击 2673 全文点击 1668 投稿时间：2008-04-01 修订日期：2008-06-02 |
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| 中文关键词 O3-FACE 冬小麦 臭氧 光合损伤 |
| 英文关键词 O3-FACE winter wheat O3 photosynthetic damage |
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| 中文摘要 |
| 在开放式臭氧浓度升高（ozone-free air controlled enrichment,O3-FACE）平台上，观测了高浓度臭氧（正常大气臭氧浓度的基础上增加50%）对2个冬小麦(Tritcium aestivum L.)品种（烟农19和扬麦16）在灌浆期内功能叶片光合损伤的情况．观测显示，整个灌浆期内2个小麦品种有关参数响应的趋势表现一致:①净光合速率（Pn）逐渐下降，在臭氧处理35 d时,烟农19和扬麦16降幅分别达到56.21%和21.82%．②荧光动力学参数Fv/Fm（最大光化学量子产量）、qp（光化学淬灭系数）、Φexc（PSⅡ有效光化学量子产量）、ΦPSⅡ（PSⅡ实际光化学量子产量）呈下降趋势,NPQ（非光化学淬灭系数）逐渐上升；在能量分配方面，吸收的光能在PSⅡ天线色素的耗散部分（%D）升高、用于PSⅡ光化学反应的部分（%P）降低，而不属于前两者的其它消耗部分（%X）变化不明显．在臭氧处理35 d时,烟农19和扬麦16的ΦPSⅡ分别下降24.42%和9.97%.③光合色素参数Chla/Chlb(叶绿素a/叶绿素b）比值上升，而Chlt/Car(叶绿素/叶黄素)的比值下降.④叶绿体内依赖Mg2+、Ca2+的ATPase(ATP酶)活性和ATP含量均增加．上述参数随臭氧处理时间延长,变化幅度和品种间的差异趋于显著，当臭氧处理35 d时，变幅最大,且烟农19变幅显著大于扬麦16．结果表明，在臭氧浓度升高环境下，作物通过增加热耗散、改变色素含量和结构、提高ATPase活性等进行防御和损伤修复．随着处理时间的增加，臭氧对冬小麦的光合损伤具有累积效应，且2个品种表现出较大的差异性． |
| 英文摘要 |
| O3-FACE（ozone-free air controlled enrichment）platform has been established for observing the photosynthetic damage induced by elevated O3 in functional leaves of two winter wheat (Tritcium aestivum L.) varieties（Yangmai 16 and Yannong 19）during grain filling stage. The results showed that the response trend of all the parameters was similar：①The net photosynthetic rate (Pn) decreased gradually and after 35 days of O3 treatment, Pn decreased by 56.21% and 21.82% for Yannong19 and Yangmai16, respectively．②Chlorophyll fluorescence kinetics parameters changed as decreased in Fv/Fm (maximal photochemical efficiency of PSⅡ in the dark),qp(photochemical quenching),Φexc(excitation capture efficiency of PSⅡ or intrinsic PSⅡ efficiency),ΦPSⅡ(actual photochemical efficiency of PSⅡ in the light), and increased in NPQ(non-photochemical quenching)；Energy distribution parameters changed as rose in %D (fraction of light absorbed in PSⅡ that is dissipated in the PSⅡ antenna)，reduced in %P (fraction of light absorbed that is used in photochemistry), and no significant changed in %X (fraction of light absorbed that is not used or dissipated in the PSⅡ antenna). After 35 days of O3 treatment，the actual photochemical efficiency of PSⅡ of Yannong19 and Yangmai16 were reduced by 24.42% and 9.97%，respectively．③It was declined in Chlt/Car (total chlorophyll content/carotinoid content) while the ratio of Chla/Chlb (chlorophyll a content/ chlorophyll b content) was increased．④There was a growth in Mg2+,Ca2+-ATPase activities and ATP contents in chloroplast．The extent of variation in the above parameters and the differences between the two varieties were enlarged as the O3 treatment time increasing and it could be found a more serious damage effect in Yannong 19 than that of in Yangmai16．In conclusion, the responses of the capacities of defense and repair systems of the two varieties to elevated O3 were reflected by increase in heat dissipation，changes in contents and composition of photosynthetic pigments, and enhancement in the ATPase (ATP enzyme) activities in chloroplast. With the time of O3 treatment elongating, there was an accumulation effect of O3 damage to wheat and a great different tolerance between the two varieties was observed. |
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