牡丹（Paeonia suffruticosa）导管的形态多样性

利用生物显微镜对牡丹一年生枝条的次生木质部离析材料进行了观察，旨在了解牡丹（Paeonia suffruticosa）的导管形态特征，为其生理生态及系统发育的合理解释及应用提供理论参考。结果表明：牡丹次生木质部具有螺纹、梯纹和孔纹三种类型的导管，穿孔板具有孔状穿孔板和梯状穿孔板两种类型，导管端壁的穿孔及尾尖形态多样，孔膜退化比较彻底。不存在明显的导管二态现象，平均长度为1 100 m，平均宽度为200 m。牡丹导管形态特征的多样性揭示了其较为复杂生理生态适应机制和相对较低的演化地位。

Morphological variety studies on vessel of Paeonia suffruticosa

The study was done to provide theoretical reference for physiological ecology and systematic development of Paeonia suffruticosa by find out the morphological characteristics of vessel. The vessel elements in stem are observed by educts of stem’s secondary xylem under bio-microscope. The Results were as follows：There are 3 types of vessel elements，that is ringed vessel，reticulated vessel and pitted vessel，the perforation plates have two types of scalarform and pitted perforation plate. The perforation on the end wall of vessel and the tip of vessel show rich variety，aperture become vestigial. There are no appearances of two states in form，the average length is 1 100 m，the average width is 200 m. Paeonia suffruticosa has stubborn adaptive mechanism of physiological ecology and complicated history of evolution.