【摘要】 本研究利用瞬时荧光、延迟荧光和820 nm光反射同步测量技术,系统比较了苹果和李的果皮与叶片在光合原初光化学反应能力方面的差异。果实不同发育时期,果皮和叶片的PSII最大量子效率没有显著区别,表明二者在PSII捕获光能并传递给反应中心P₆₈₀的能力方面没有区别。然而,瞬时荧光J点和I点的差异表明,果皮P₆₈₀捕获的电子到达Q_A的能力和PSI的活性显著低于叶片。果皮和叶片瞬时荧光的差异还表明,相对于叶片,果皮PSII供体侧的电子传递能力也更低。延迟荧光诱导动力学和衰减动力学结果均表明,果皮P₆₈₀供体侧和受体侧的电子传递能力均较叶片低。与叶片相比,果皮820 nm光反射的初始下降速率显著更低,表明果皮PSI的原初光化学反应能力显著低于叶片。总之,3种不同技术的结果互相补充和印证均表明果皮2个光系统的原初光化学反应的能力较叶片显著更低,这可能是果皮对强光更敏感的关键因素之一。更多还原

【Abstract】 In this study, the capacity of phytochemistry between fruit peels and leaves of apple and plum was compared using simultaneous measurements of prompt fluorescence, delayed fluorescence and 820nm light reflection. At different developmental stages of fruits, no difference was found between fruit peels and leaves in the maximum quantum yield of PSII, indicating that they had similar capacities in light energy capture by PSII and the following transfer to P680. However, differences in J-and I-step of prompt fluorescence suggested that the capacity of photosynthetic electron transport to QA and the capacity of PSI were both lower in fruit peels compared with leaves. The differences in prompt fluorescence between peels and leaves also indicated that the electron transfer capacity at the donor side of PSII was also significant lower in fruit peels. Induction and decay kinetics of delayed fluorescence showed that photosynthetic electron transfer capacities at the donor and acceptor sides of P680 were both lower in fruit peels compared with leaves. The initial decrease of light reflection at 820 nm was slower in fruit peels than leaves,indicating that the phytochemistry capacity at PSI was lower in peels. In general, the results from three techniques complemented and confirmed each other. The phytochemistry capacities at both photosystems were much lower in fruit peels than leaves, which might be one the key factors that why fruit peels are more sensitive to high light.更多还原