【摘要】 采用LI-6400便携式光合作用仪观测了不同灌水技术下核桃树光合特性,并对核桃树净光合速率与影响因子进行相关性分析。结果表明,①净光合速率、气孔导度和水分利用效率的日变化呈"双峰"型曲线,蒸腾速率和大气温度呈"单峰"型曲线,空气相对湿度和胞间CO2摩尔分数呈大"U"型曲线。②净光合速率和大气温度、蒸腾速率、气孔导度显著正相关,与空气相对湿度、胞间CO2摩尔分数负相关;对核桃树净光合速率影响最大的是气孔导度和胞间CO2摩尔分数,其次是蒸腾速率和空气相对湿度。③与地面灌溉相比,微灌处理均能提高核桃水分利用效率,尤其是滴灌3管技术。滴灌3管技术是核桃树最优供水方式。更多还原

【Abstract】 Photosynthetic characteristics of walnut tree under different irrigation techniques were measured using LI-6400portable photosynthesis system and the correlations between net photosynthetic rate and influence factors of walnut trees were analyzed.The results showed that:①Diurnal variations of net photosynthetic rate,stomatal conductance and water use efficiency were all double-peak curves;Diurnal variations of transpiration rate and air temperature were single peak curves;Diurnal variations of air relative humidity and intercellular CO2concentration were"U"curves.②The net photosynthetic rate was positively correlated with air temperature,transpiration rate and stomatal conductance while the net photosynthetic rate was negatively correlated with air relative humidity,intercellular CO2concentration;the net photosynthetic rate of walnut tree was mainly influenced by stomatal conductance and intercellular CO2concentration,followed by the transpiration rate and relative humidity.③Compared with the surface irrigation, micro-irrigation treatment could improve water use efficiency of walnut,especially irrigation technique with 3tubes.So,irrigation technique with 3tubes is the optimal choice of supplying water for walnut tree.更多还原