光合功能叶是生理活性最强,能表征植株在该时期特点的叶片。一般是把枝条中上部刚刚完成扩大生长,叶色浓绿的叶片作为功能叶进行某些生理指标的测定。但是,随着植株的不断生长,功能叶至下而上依次递换,用肉眼难于确定。为此,我们对杨树一年生无性系苗光合功能叶进行了测定。 Photosynthetic functional leaves are the most physiologically active leaves that characterize plants during this period. Generally, the upper part of shoots has just completed the expansion and growth, and leaves with thick green leaves are used as functional leaves for the determination of certain physiological indexes. However, with the continuous growth of plants, the function leaves are sequentially switched from bottom to top, which is difficult to determine with the naked eye. To this end, we measured annual photosynthetic functional leaves of poplar clones.