以2个芍药品种大富贵与红艳争辉为材料，测定了芍药蕾期不同叶位叶面积、叶片SPAD值、净光合速率(Pn)。结果表明 ，现蕾初期叶面积从大到小依次为基部、中部、顶部，至现蕾末期，以中部叶面积最大；不同叶位的叶面积随着花蕾的发育不断增大，现蕾30 d叶面积达到最大，约为现蕾初期的3倍；不同叶位叶片的SPAD值在蕾后10 d迅速增大，之后增加幅度降低，大富贵高于红艳争辉；现蕾初期叶位越高，SPAD值越低； 不同叶位叶片的Pn值随着生长发育均呈直线上升趋势，蕾后30 d的Pn值约为现蕾初期的3倍，大富贵的Pn值高于红艳争辉，不同叶位叶片的Pn值与SPAD值呈显著正相关。

Two cultivars of Paeonia lactiflora Dafugui and Hongyanzhenghui are used as experimental materials， test leaf area， SPAD value， net photosynthetic rate(Pn) values in different leaves position of Herbaceous peony at the buds period， The result shows that Leaf area enlarged with the development of flower bud and reached the maximum on the 30 th day of squaring period， which is 3 times as those in the initial stage of squaring period . Leaf area ranked in the decreasing order is basal leaves， middle leaves， top leaves， the initial stage， but the middle leaves became the highest at the terminal stage . SPAD value of leaves increasd greatly within the initial 10 days， and increasd a little after that . The SPAD value of Dafugui leaves in different leaf position is higher than that of Hongyanzhenghui . In the initial stage of squaring period， the higher position of the leaves， the lower the SPAD value . With the development of the leaves， Pn value of leaves in different position rose all straightly， and about 3 times in 30 d as in the initial stage . The Pn value in Dafugui is always higher than that in Hongyanzhenghui . Pn values and SPAD values show significant linear positive correlation in different leaves position .

S682.1

甘肃省农业科学院科技创新项目(2012GAAS11-2)；甘肃省科技重大专项(1203NKDK019)