中文摘要：

研究水氮耦合对葡萄树光合、果实品质及产量变化的影响,对于发展葡萄产业具有科学指导意义。本研究利用Li-6400便携式光合仪,在葡萄浆果成熟期对不同水分亏缺及施氮水平下的酿酒葡萄进行了光合日变化测定,同时对可溶性固形物及产量进行测定。结果表明,土壤水分亏缺会导致气孔导度、蒸腾速率及光合速率的下降,而施氮量的增加能消减下降趋势。低氮条件下,轻度和重度水分亏缺分别使葡萄产量降低32.2%和49.9%,使浆果可溶性固形物含量分别提高6.9%和13.9%;氮素充足条件下,尽管存在水分亏缺,但葡萄产量无显著降低,且浆果可溶性固形物含量提高16.2%。该研究对于认识葡萄水肥耦合关系、指导水肥管理实践提供了理论依据。

英文摘要：

Photosynthates, the products as the source for plant dry matter accumulation, have a direct effect on plant growth and the formation of yield and grain quality. Soil water content and nitrogen concentration are the main factors which influence plant growth and dry matter accumulation. The study of grapevine photosynthetic characteristics, fruit quality and yield in desert oasis area, is of important significance for wine grape industry development. A field experiment was conducted during the wine grape growing season in Wuwei, China in 2010. The wine grape （Merlot） was planted in 1999 with 2 nitrogen fertilizerand 3 soil water content levels. The nitrogen treatments were HN （high nitrogen, 170 kg/ha） and LN （low nitrogen, 130 kg/ha）, and.the water treatments were CK （ 70% of the field capacity）, M （55% of the field capacity） and L （ 40% of the field capacity）. The diurnal dynamics of leaf photosynthetic rate was measured at sunny days during berry growth period （July 27th） and berry expansion period （August 26th） using a Li6400 portable photosynthesis system, and the net photosynthetic rate （Pn）, transpiration rate （Tr）, stomatal conductance （Gs） and leaf water use efficiency （WUE） were read and calculated. Meanwhile, the total soluble solid content and grape yield were also measured. The meteorological parameters （solar radiation （Ra）, air temperature （Ta）, relative humidity （RH）） were recorded for the whole grape growing period. The results showed that the diurnal cycles of leaf net photosynthetic rate and transpiration rate appeared a ＂M＂ type under different water and nitrogen conditions, with an more obvious photosynthetic rate depression as soil water content decreasing. The lower soil water content would cause the decrease of stomatal conductance, transpiration rate and photosynthetic rate. The severe water deficit significantly reduced the leaf water use efficiency, and the moderate water deficit would improve the water use efficiency of