Studies on photosynthetic characteristics of Vitis vinifera L.cv.Cabernet sauvignon during berry expansion period in Weibei Rainfed Highland

【Objective】 The study was to analyze the photosynthesis characteristics of the grapevines(Cabernet Sauvignon) in the hilly area and the plain.【Method】 The photosynthesis characteristics of the grapevines(Cabernet Sauvignon) were studied with LI-6400 portable photosynthesis system in two vineyards in the Yaozhou area Shaanxi Province.【Result】 The results show that the diurnal variation of net photosynthetic rates of leaves in the mountain area or in the plain had similarities,showing double-peak curve.The first peak appeared at 10:00 and the second peak after 15:00 was smaller,with a lower value of the second peak than that of the first peak.The net photosynthetic rates,transpiration or intercellular CO2 concentration of leaves had prominence difference in the hilly and the plain,and water use efficiency or stomatal conductance had not prominence difference.In the Pn-PAR response curve,Pn max and apparent quantum yield were 14.40 μmol/(m2·s),0.036 and 12.58 μmol/(m2·s),0.035.In the Pn-Ci response curve,they were 23.99 μmol/(m2·s),0.061 and 18.43 μmol/(m2·s),0.059.(R20.94).The pigment content showed that the photosynthesis pigment in the hilly was evidently higher than that in the plain.Under different altitude conditions,the net photosynthetic rates had a significantly positive relationship with photosynthetic active radiation,transpiration and stomatal conductance,but an obvious negative relationship with intercellular CO2 concentration.【Conclusion】 It indicates that the grapevines in the hilly can get a higher light effect and higher production than that in the plain.