不同品种来源广藿香叶表皮毛特征比较分析

Comparative analysis of leaf epidermal hair characteristics of Pogostemon cablin from different origins

关键词:  广藿香, 叶表皮毛, 显微特征, 分类, 采收期

Key words:  Pogostemon cablin, leaf epidermal hair, microscopic characteristics, classification, harvesting period

摘要:

叶表皮毛特征作为药用植物的“微性状”特征,被越来越多地应用于植物学分类研究中,表皮毛的生长发育状态可以直接影响药材的整体品质。广藿香主要含有挥发油成分,叶表皮毛中的腺毛是其挥发油的主要合成分泌场所,而非腺毛可以起到保护作用,影响其长势和产量。为了探讨叶表皮毛特征在广藿香品种鉴别方面的意义,该研究以8个不同品种来源以及2个采收期(6月末和10月末)的广藿香的顶叶、第4对生叶及底叶为材料,采用水合氯醛透化法制片,于光学显微镜下观察拍照,使用Microsoft Excel 2019统计数据,采用SPSS 23.0统计学软件对叶表皮毛密度、腺毛直径进行方差分析、主成分分析和聚类分析。结果表明:同一品种来源,不同采收期的广藿香叶表皮毛密度有显著性差异,6月末采收的广藿香叶表皮毛密度显著低于10月末采收的; 根据叶表皮毛(非腺毛、头状腺毛、盾状腺毛)密度及腺毛直径,可将相同采收期的8个不同品种来源广藿香分为4类,且可以将已知品种来源的南香、肇香和牌香分开,与传统分类结果有着很好的一致性。叶表皮毛密度和腺毛直径在广藿香的分类中具有一定的参考意义,并为广藿香药材品质形成机制的研究提供参考。

Abstract:

The characteristics of traditional Chinese medicine are not only the appearance of the medicinal material, but also the external manifestation of its internal tissue structure and the chemical components. Pogostemon cablin is one of the top ten southern medicines which has high economic value. Generally, it is divided into four cultivation types and two chemical types according to the cultivation origin and the composition of volatile oil. However, the characteristics are very similar, and it is difficult to determine the classification of different cultivation varieties. Leaf epidermal hair characteristics as micro-morphology of medicinal plants, are increasingly used in botanical taxonomic research, and the growth and development of epidermal hair can even directly affect the quality of the medicinal material. The glandular hairs of P. cablin are the main synthetic and secretory site of its volatile oil, while the non-glandular hair can play a protective role, affecting its growth and yield. In order to explore the significance of leaf epidermal hairs characteristics in identifying P. cablin varieties, and to provide a reference for the research on the quality formation mechanism of P. cablin. This study was conducted on apical leaves, the fourth pair of leaves and bottom leaves of P. cablin from eight different varieties sources and two harvesting periods(end of June and end of October). The microscope slide was processed by chloral hydrate permeation, and photographed under an optical microscope. The results of variance analysis showed that there were significant differences in the hair density of the leaves of the P. cablin from the same variety in different harvesting time. The epidermal hair density of the P. cablin leaves harvested at the end of June was significantly lower than that of the end of October. The results of principal component analysis and cluster analysis were the same, the P. cablin of eight different oringins of the same harvesting period can be divided into four categories according to the leaf epidermal hair density and the diameter size of glandular hair, and Nanxiang, Zhaoxiang and Paixiang can be separated, which was in good agreement with the traditional classification results. The epidermal hair density and the diameter size of glandular hair of leaves have some reference value in the classification of P. cablin.