喷施高岭土对高温和强光胁迫下福克葡萄叶片光合特性的影响

Effects of kaolin on chlorophyll fluorescence and photosynthesis of Frontanec grape leaves under high temperature and strong light stress

高温和强光是夏季葡萄生产面临的主要生态逆境胁迫,严重时会造成叶片日灼。为保护葡萄叶片光系统功能,减轻叶片所受胁迫,以2年生福克葡萄为试材,叶面喷施9‰高岭土,测定高温、强光胁迫下葡萄叶片叶绿素荧光及光合气体交换参数的变化。结果表明:随着胁迫时间的延长,9‰高岭土处理显著降低了PSⅡ供体侧受伤害程度(W_(K)),提升了PSⅡ受体侧电子传递的量子产额(φEo);显著降低了葡萄叶片单位面积PSⅡ反应中心对光能的吸收(ABS/RC)及光能热耗散(DIO/RC)的量,增加了反应中心活性数量(RC/CSM);显著提高了最大光量子效率(Fv/Fm)、实际光化学量子产量(Ф_(PSⅡ))及光合性能指数(PI_(ABS)),进而促使净光合速率(Pn)显著提升。综上,在高温和强光胁迫下对叶面喷施9‰高岭土,可减少叶片对光能的吸收,缓解叶片所受光抑制,降低PSⅡ的损伤,保护叶片光合系统,提高叶片净光合速率。

High temperature and strong light are the main ecological stress for grape production in summer, which can cause sunburn of leaves. In order to investigate the effect of spraying 9‰ kaolin on the grape leaves on the protection of photosystem function and response of the stress on leaves, the two-year-old Frontanec grapevine were selected and the chlorophyll fluorescence and photosynthetic changes of grape leaves were determined under high temperature and strong light stress. The results showed that with the prolongation of stress time, 9‰ kaolin treatment significantly reduced the degree of donor side injury(W_(K)) and increased the quantum yield(φEo) of electron transport on the recipient side of PSⅡ. The absorption of light energy(ABS/RC) and the amount of light energy heat dissipation(DIO/RC) of PSⅡ reaction centers per unit area of grape leaves were significantly decreased, and the number of active reaction centers(RC/CSM) was increased. The maximum photonic quantum efficiency(Fv/Fm), the actual photochemical quantum yield(Ф_(PSⅡ)) and the photosynthetic performance index(PI_(ABS)) were significantly increased, and the net photosynthetic rate(Pn) was significantly increased. In conclusion, the application of 9‰ kaolin on leaves under high temperature and strong light stress can reduce the absorption of light energy, alleviate the photoinhibition of leaves, reduce the damage of PSⅡ, protect the photosynthetic system of leaves, and increase the net photosynthetic rate of leaves.