渭北旱塬70年来冬小麦品种更替中光合特性的研究

Study on the Photosynthesis Characteristics in the Process of Wheat Cultivars Replacement During Seventy Years in Loess Plateau

通过田间试验测定不同小麦品种整个生育期光合特性以及灌浆期光合特性的日变化。结果表明,随着渭北旱塬小麦品种的改良,不同品种生育后期旗叶净光合速率(Pn)呈递增趋势,现主推品种长旱58灌浆期Pn、蒸腾速率(Tr)、气孔导度(Gs)都处于较高水平,日均Pn达11.58μmol.m-2.s-1,较40年代品种五指麦提高了3.75μmol.m-2.s-1,增幅47.79%,日均Tr及Gs较五指麦增加了25.37%和42.84%。

Field experiments were conducted to study the evolution characteristics of their flag leaf photosynthesis.The results indicated that in wheat cultivars improvement in the Losee Plateau,with the cultivars grown,the net photosynthetic rate has increasing tendency in late growth stage.the current cultivars had higher photosynthesis rate（Pn）,transpiration rate（Tr） and stomatal conductance（Gs） of flag leaf in grain filling stage,the daily mean Pn increased from about 11.58 μmol·m-2·s-1 of current cultivar Changhan 58 to 3.75 μmol·m-2·s-1 of old cultivar Wuzhimai,with the increasing rate of 47.79%,and the daily mean Gs and Tr is 25.37% and 42.84% respectively.