关键词: 葡萄, 臭氧胁迫, 褪黑素, 光合作用, 叶绿素荧光

Abstract:

To investigate the effect of exogenous melatonin（100 nmol · L^-1）on photosynthetic characteristics of grape seedlings under ozone stress（110 nL · L^-1），potted Cabernet Sauvigon grapevine were used as materials to be irrigated with melatonin，gas exchange parameters and OJIP fluorescence transient were tested，and combined with chlorophyll fluorescence quenching analysis. The results showed that，the exogenous melatonin increased the content of chlorophyll a，chlorophyll b，carotenoids and the ratio of chlorophyll a/b under ozone stress，increased the net photosynthetic rate（P_n）of grape leaves and number of active reaction centers per unit area（RC/CS_m），promoted the probability of a trapped exciton moves an electron into the electron transport chain beyond QA（Ψ_o），which reduced the photoinhibition under ozone stress. These results suggested that exogenous melatonin promoted the chlorophyll content  under the ozone stress，reduced the damage of ozone stress on grape leaf photosynthesis by improving the energy distribution of grape leaf photosystem.

Key words:  grape, ozone stress, melatonin, photosynthesis, chlorophyll fluorescence