四种番荔枝科(Annonaceae)植物导管分子及其穿孔板的比较观察

Comparative observation on vessel elements and perforation plates in four species of Annonaceae

关键词:  导管, 木材解剖, 暗罗属, 假鹰爪属, 紫玉盘属, 瓜馥木属

Key words:  vessel, wood anatomy, Polyalthia, Desmos, Uvaria, Fissistigma

摘要:

番荔枝科是被子植物基部类群,木兰目中最大的一个科。为了解暗罗属(Polyalthia)的海南暗罗(Polyalthia laui)、假鹰爪属(Desmos)的假鹰爪(Desmos chinensis)、紫玉盘属(Uvaria)的山椒子(Uvaria grandiflora)、瓜馥木属Fissistigma)的瓜馥木(Fissistigma oldhamii)四个种的导管与穿孔板的形态学特征,该研究利用扫描电子显微镜(SEM)对其导管分子及穿孔板形态进行观察,首次展示了这4属4种的导管分子与穿孔板的形态特征,并对其导管的长度与直径进行了分析与比较。结果表明:这四个种导管分子端壁均为单穿孔板,部分穿孔板具尾,不同种在导管与穿孔板形态上具有明显的差异; 长度与直径的统计学分析显示其种间差异极显著,导管长度与直径的相关性分析显示其没有相关性。综合导管的形态学特征与统计学分析结果,该研究认为在这四个种中,假鹰爪的导管分子直径与长度变化幅度都不大,长度较短,直径最大,穿孔板平截,不具尾或具小尾,其导管分子处于较高的演化水平。

Abstract:

Annonaceae is the largest family of Magnoliales in the basal angiosperms. In recent years, some studies of wood anatomy and vessel have been done, but most of the studies are about Annona, and the researches of other genera are few, so the morphology of vessels and perforation plates of many species in the family are unknown. The wood of Polyalthia laui, Desmos chinensis, Uvaria grandiflora, and Fissistigma oldhamii from Annonaceae were collected from Hainan Province of China. Fixation of the healthy and fresh wood of each species was done using FAA(Formalin Acetic Acid)and materials were treated with Jeffrey's Fluid. The authors observed the vessel elements in the secondary xylem of the four species under the scanning electron microscope(SEM)and their vessel elements were compared. The features of vessel elements and the perforation plates in the four species under SEM were shown for the first time, and their differences were illustrated. Statistical analysis about the length and diameter of vessel elements was made, too. The results showed that the perforation plates of the four species were all simple perforation plates, with or without tails. There were obvious differences in morphology of vessel elements. Vessel elements of Polyalthia laui were long and its perforation plates were oblique. Perforation plates of Desmos chinensis were truncated, and its vessel elements were shorter, and its diameter was the biggest in four species. Perforation plates of Uvaria grandiflora were oblique and vessel. Vessel elements of Fissistigma oldhamii were shortest and its perforation plates were truncated, no tail or with a small tail. The statistical analysis of length and diameter of vessel element showed that the differences of four species are significant. The correlation analysis of length and diameter showed that they were irrelevant. In the synthesis of factors, vessel elements of Desmos chinensis were shorter, and its diameter was the biggest in the four species, and its simple perforation plates were truncated, no tail or with a small tail. The authors think that the vessel of D. chinensis has higher level of evolution than the others. The results of this paper will provide new and more evidences for anatomy and systematics of Annonaceae.