Studies On The Germplasm Of Zanthoxylum Nitidum (Roxb.) DC.

In this paper, based on the specimen examination in many herbaria and field investigation, the germplasm resources of Zanthoxylum. nitidum in Guangxi are revised. The variation of morphological characters of the two variaties and three types of Z. nitidum (Roxb.) DC. is analyzed, the micro-morphology of the leaflet and nerve is observed, the chromosome karyotype is researched, and the ecological characters and geographic distribution are analyzed. The content of nitidinechloride and neoherculin in 13 samples of Z. nitidum from different areas and 8 samples of counterfeits (or substituents) materials is determined. After collecting 50 germplasm resources of Z. nitidum, descriptors and data standard for the germplasm resources of Z. nitidum is compiled.1 Field investigationBy field investigation, it is showed that there were 18 different species and variaties used as local material of Radix Zanthoxyli in Guangxi. The real origin plant Z. nitidum has two variaties named Z. nitidum (Roxb.) DC. var. nitidum, which is made of three types too, and Z. nitidum (Roxb.) DC. var. tomentosum Huang. They are all major used as medicinal materials. The used amount of Z. nitidum var. tomentosum is more than that of Z. nitidum (Roxb.) DC. Through the survey, it can be assessed that total deposit of wild resources of Z. nitidum (dry weight) is about 2600 ton. The resource is obviously in great shortage.2 Analysis on the morphological traitsThe experiment results show the characters of plant morphology of Z. nitidum are relative to the growing landform condition of the plant. But there is no obvious distinguish on plant morphologic between Z. nitidum var. nitidum (including three types) and Z. nitidum var. tomentosum, the difference of morphological character of each variaty and type is mainly on leaf texture and pubescence on the surface of plant. The leaf texture is the first taxonomic character because of its stabilization among the type, and the characters of prickle, leaf margin, fruit size and oil dot, which are not the stable within the type, should be treated carefully. And it still needs further studies on the taxonomic value of the flower morphological traits.3 Study on the micro-morphology of the leafletIt is observed that there is obvious distinguish between original variety and Z. nitidum var. tomentosum, and between Typeâ…¢and other two types on the surface characters of leaflet. There are some special characters of leaflet nervation for typeâ… and Z. nitidum var. tomentosum different from others. As a result, micro-morpology of the surface and nervation of the leaflet of Z. nitidum is significant for classification and identification.4 Analysis on the chromosome karyotypeIt is observed that chromosome numbers of two varieties and three types of Z. nitidum are all 2n=2x=68. The karyotype formula of typeâ…¡is K (2n) =2x=2st+13sm+19m.5 Ecological charactors and geographic distributionAll the variaties and types of Z. nitidum are distributed in all around Guangxi. The Typeâ… of original variety is mainly distributed in the east and southeast areas of Guangxi, especially in Pingnan, Wuzhou, Yulin. The Typeâ…¡is mainly distributed in west and northwest areas of Guangxi, especially in Lingyun, Donglan. The Typeâ…¢is mainly distributed in southwest of Guangxi, especially in Longzhou, Pingxiang. Z. nitidum var. tomentosum is widely distributes in whole Guangxi. The plant is distributed in sparsely manner in most places except in Pingxiang, Fangcheng, Wuzhou, etc.All the variaties and types can be seen in the warm damp zones below the altitude of 900m, such as the roadside of mountain, valley, and forest edge. There is some relationship between the community characters and the growing landform condition. The type I usually growing in upland area, while typeâ…¡, typeâ…¢and Z. nitidum var. tomentosum in rock mountain area. In its growth community structure, the structure of arbor layer is unique, but the ones of shrub and herbage are relative complex.6 Analysis on the chemical constituentsThe analysis results showed that there is a great different content between nitidinechloride and neoherculin in Radix Zanthoxyli (including Z. nitidum var. nitidum and Z. nitidum var. tomentosum) from 13 different growing areas in Guangxi. The content of nitidinechloride is 0.0035% to 0.36%. The content of neoherculin is 0.0011% to 0.0197%. It still needs further studies on the correlation between the content of nitidinechloride and neoherculin to the different types and geographic distribution. Except the content of Toddalia asiatica Lam is similiar to that of Z. nitidum, the chemicals in other 7 counterfeits (or substituents) are in lower content or cannot be detected. These species should not be used. Based on above studies, it's confirmed that it is significance for the division of two varieties and 3 types in Z. nitidum recorded in the book named Flora of China. This paper carried out systemic revision on the germplasm of Z. nitidum in Guangxi. This study will supply an important study data to reasonable and reproduced utilization of Z. nitidum resources.