梨树叶片光合特性研究

STUDIES ON PHOTOSYNTHETIC CHARACTERS OF PEARS

以金水二号、黄花梨为试材，对新梢叶片的生长动态、不同叶位叶片的解剖结构及叶片的光合特性进行了观察、测定，结果表明：随叶位上升，叶片栅栏组织厚度增加，细胞变长，细胞间隙及海绵组织减小；黄花梨叶片的水分蒸气压饱和差、蒸腾系数大于金水二号；叶片光合速率、气孔ＣＯ＿２通量随叶龄增加而增加，当叶片几乎停止扩大时达到最大值，黄花梨为１２．５８ＣＯ＿２μｍｏｌ／ｍ￣２·Ｓ、金水二号为１１．６２ＣＯ＿２μｍｏｌ／ｍ￣２·Ｓ，气孔阻力的变化趋势与此相反。

The new leaf growth curve and anatomical structure of different position of twopear varieties,Huanghua and Jinshui-2 were measured as well as the leaf transpiration,stom-atal conductivity, and net photosynthetic rate and the results showed that the thickness ofieaf palisade tissue and the length of the cell increased as leaf position rised,while the roombetween cells and the spongy tissue decreased.The leaf vapor pressure deficit and transpira-tion coefficient of Huanghua was greater than those of Jinshui-2. The leaf photosynthetic rateand stomataI CO_2 flow increased as the leaf age got older.The stomatal CO_2 flow reached tothe maximum rate of 12.58 CO_2 μmol/m￣2·s(Huanghua)and 11.62 μmol CO_2/m￣2·s(Jinshui-2),when the leaves stopped growing. Stomatal resistance revealed the opposite trend.