Study on photosynthetic adaptability of introduced grapevine cultivar in Ningxia area

In order to understand the photosynthetic physiological adaptability,diurnal courses of net photosynthetic rate(Pn),light response curves and CO2 response curves of 2 grapevine cultivars(Vitis vinifera L.and Vitis vinifera L.) were measured by Li-6400 portable photosynthetic system.The results showed that:① The diurnal course of Pn of V.vinifera L.presented a double peak curve with an evidently midday depression in July and August,a single peak curve in June was also observed.By contrast,diurnal course of Pn of V.vinifera L.manifested single peak curve during the whole experimental period.② except for July,the stomatal conductance(Gs),evaporation rate(E) and water use efficiency(EUE) were significantly higher than that of V.vinifera L..③ V.vinifera L.had a higher apparent quantum yield(AQY),whilst Vitis vinifera L.had a higher light saturation point(LSP),light compensation point(LCP),maximum photosynthetic rate(Pnmax) and dark respiration rate(Rd).④ Compare with V.vinifera L.,V.vinifera L.possessed a higher photosynthetic capacity(Amax),CO2 saturation point(CSP),maximum carboxylation rate(Vcmax),maximum electron transportation rate(Jmax) and photorespiration rate(Rp).Base on those observations,we postulated that the V.vinifera L.has a better adaptability and photosynthetic ability than that of V.vinifera L.,which probably indicate its high yield.