Effects of Field High Temperature on Antioxidant and Photosynthetic Characteristic of Grapes in Different Trellis Systems
To explore the physiological responses of grapes to high-temperature stress within various trellis systems,the effects of three trellis-system,V-shaped(Vs),Flying Bird-shaped(Fs),and H-shaped(Hs),on canopy temperature,leaf antioxidant system and photosynthetic fluorescence parameters were investigated in the field high temperature in summer.Shine Muscat grapevines were used as the experimental material.The results showed that in high-temperature conditions,Fs exhibited the lowest canopy temperature,while which of Hs was the highest.From the 3rd to the 15th day of high-temperature stress,the contents of malondialdehyde(MDA),superoxide radical(O2(-·)),hydrogen peroxide(H2O2),proline and soluble protein in the leaves of all three trellis systems showed a continuous upward trend with the days of high-temperature stress increasing,except for the soluble protein content in Hs,which first showed an upward trend and then a downward trend.The activities of superoxide dismutase(SOD),peroxidase(POD),and catalase(CAT),as well as the relative expression levels of VvSOD,VvPOD,and VvCAT all first showed an upward trend and then a downward trend.The analysis of diurnal variations in photosynthetic fluorescence parameters showed that the net photosynthetic rate(Pn),stomatal conductance(Gs),transpiration rate(Tr),maximum fluorescence yield(Fm),maximum energy conversion efficiency(Fv/Fm),potential photochemical activity(Fv/Fo),actual photochemical efficiency(ΦPSⅡ),photochemical quenching coefficient(qP),and electron transport rate(ETR)in the leaves of all three trellis systems were decreased under high temperature at midday,while the intercellular CO2 concentration(Ci),initial fluorescence(Fo)and non-photochemical quenching coefficient(NPQ)were increased.Under high-temperature,the lowest O2(-·),H2O2,and MDA contents,as well as relative conductivity were found in Fs,while it had the highest antioxidant enzyme activities and expression levels of the corresponding genes,Pn and photochemical efficiencies.In conclusion,heat resistance of Fs was stronger,and more suitable for adoption in the southern high temperature cultivation environment.The results of this study provide a theoretical basis for research on heat-resistant cultivation of grapes.
high temperaturetrellis systemsgrapeantioxidant systemphotosynthetic fluorescence
万方数据
维普
