烤烟光合作用的生育期变化及其与环境因子的关系

利用Li6400光合仪研究了不同部位烟叶光合作用的周期性变化,结果表明:不同部位烟叶的Pn、Tr和Gs的变化表现出不同的趋势,均出现了高峰和低谷,但不同部位烟叶的Pn、Tr和Gs高峰和低谷的高低和出现时间有所不同。生育期内中部叶和上部叶的Pn、Gs平均值均大于下部叶,以中部叶最大;Tr平均值大小依次为中部叶、下部叶、上部叶。对Pn影响最大的因子是Gs,其次是VPD、RH、Ta和PAR;对Tr影响最大的因子是VPD,其次是Ta、RH、Gs和PAR。

Change in Photosynthesis of Flue - cured Tobacco at Different Growth Stages and Its Relationship with Environmental Factors

The cyclical changes in the photosynthesis of different parts of tobacco leaves were studied by using Li6400 photosynthetic apparatus.The results showed that the Pn,Tr and Gs of different parts of tobacco leaves had different change trends,and they all appeared peaks and valleys,but the value and appearance time of their peaks and valleys were not the same.In the growth period of tobacco plants,the average values of Pn and Gs of the middle leaves and upper leaves were larger than those of lower leaves,and those of the middle leaves were the largest.The average value of Tr revealed the following order: middle leaves>lower leaves>upper leaves.Gs had the greatest impact on Pn,followed by VPD,RH,Ta and PAR.VPD had the greatest impact on Tr,followed by Ta,RH,Gs and PAR.