臭氧胁迫对3个葡萄品种叶片原初光化学反应的影响

Responses of primary photochemical reactions in the leaves of three grape cultivars to the ozone stress

本试验以5BB、赤霞珠、Frontenac(福克)为试材,用321μg/m3浓度的臭氧进行胁迫处理3 h后,采用连续激发式荧光仪测定并分析了葡萄叶片快速叶绿素荧光诱导曲线参数的变化,以期探究臭氧胁迫对葡萄叶片光合原初反应的影响机制。结果显示,经过胁迫以后,3个品种的最大光化学效率Fv/Fm、光合性能指数PIABS、单位面积吸收的光能ABS/CSm、单位面积内反应中心的数量RC/CSm、捕获的激子将电子传递到QA以后的其它电子受体的比率ψO显著降低,2 ms时有活性的反应中心的关闭程度Vj和用于热耗散的量子比率φDo显著增大,且福克变化幅度最大,赤霞珠次之,5BB最小。说明臭氧胁迫对葡萄光合原初反应产生了影响,主要表现为可减少单位面积吸收的光能,抑制电子从QA向下的电子传递和减少单位面积内有活性的反应中心的数量;在3个供试品种中,福克对臭氧胁迫最敏感,赤霞珠次之,5BB敏感性较低。

5BB, Cabernet Sauvignon and Frontenac were used as material to treated with ozone stress （321μg/m3） for 3 hours, the responses of primary photochemical reactions were studied by analyzing chlorophyll a fluorescence transient. The results showed that the maximum of photochemical efficiency （Fv/Fm）, the energy performance index based on the absorption of light （PIABS）, the energy absorption of per unit area （ABS/CSm）, the number of reaction center in per unit area （RC/CSm） and the ratio of the exciton used to promote electron transfer to other electron acceptor in the electron transport chain than QA takes up to the exciton used to push the QA reducted （ψO） decreased significantly, the degree of the active reaction center closed at 2 ms （Vj） and the ratio of quantum for heat dissipation （φDo） increased significantly. And, Frontenac was most affected, followed by Cabernet Sauvignon, 5BB was little affected. Which indicated that ozone affected on photosynthetic original reaction of grapevine, mainly showed reducing the absorption of light energy per unit area, inhibiting electronic transfer down from QA and a reduction in the number of the active reaction center in unit area. In conclusion, Frontenac was the most sensitive to ozone, followed by Cabernet Sauvignon.