| Zanthoxylum is the most extensively distributed genus of Rutaceae.There are about 250 species all over the world especially distributed in Asia, Africa, Oceania, the tropical and subtropical regions of North America. There are 39 species and 14 varieties in China. These plants are distributed in the northern and southern parts of China, and along with the in drainage area and riverbanks of Yangtze River. There are 18 species and 8 varieties and 1 form in Sichuan province & Chongqing Municipality. The fruits, roots, stems, leaves of Zanthoxylum possess medicinal properties such as analgesic, narcotic, antimicrobial, insecticidal and anti-carcinogenic etc. The fruits, which have high economic value, are ordinarily used as seasoning and antiseptic purposes. They are also important species for ecorestoration, especially in mountain ecosystems.This paper studies the species relationship within genus Zanthoxylum in Sichuan & Chongqing by morphological and molecular method through much analysis software for the first time. The study can provide a theoretical base for utilizing and protecting the germplasm resources of Zanthoxylum plants.The main results of the study are as follows:1 Morpho-genetic relationshipHere SPSS soft was used to analyze the genetic relationships of the Zanthoxylum plants in Sichuan and Chongqing, by Q cluster, R cluster and principal component analysis method.(1) Based on 44 morphological characters of 16 species, 6 varieties and 1 form of Zanthoxylum, Further, Neighor cluster method was used to analyze the data. The result of Q cluster analysis showed that the combinations of most species of Zanthoxylum position are the same with the actual systematic taxon, except Z. echinocarpum and Z. ovalifolium v. spinifolium. They can be clustered together with the Subgen. Fagara as they showed close relationship with the same. (2) The analysis of the R clustering indicated that 44 characters in the experiment were independent of each other. The number of the perianth, differentiation of perianth into calyces and petals, and the character of style etc were found to be quite significant. It was observed that if there is a differentiated perianth (i.e. calyx and petal), the styles of the female flowers were separated and the number of the perianth was in equation.(3) The result of principal component analysis showed that the part of the characters had great relativity. 9 principal components were chosen in the principal component analysis by their total cumulative contributing rate above 85ï¼…, and the total cumulative contributing rates of 9 principal components reached up to 85.519ï¼…. The contribution ratio of principal componentâ… (25.748ï¼…) was the first; which reflects the character trait of lives. The second was principal componentâ…¡(14.850ï¼…) which reflected the shape of leaves. It was followed by the principal componentâ…¢which reflected the traits of branches and fulcrumand had a ratio 10.725ï¼…. The fourth was principal componentâ…£which reflected the traits of petiole and petiole and gland and its ratio was 8.844ï¼…. The differences of the above mentioned principle components embodied the typical traits of every species basically.2 The RAPD analysis of genetic relationship(1)The relative relationship of Zanthoxylum were studied by RAPD. There were 244 RAPD loci amplified by 15 random primers, i.e. every primer amplifying 16.3 bands in average. Among these, the polymorphic band 243 was found to be accounting for 99.6ï¼…in total bands. The MW of amplified bands is between 396 and 3000 bp, especially mustered from 1000 to 1600 bp.(2)According to the result of PCR, the genetic comparability quotient of 11 tested materials was calculated by the software of NTSYS-pc2.02a. The changing range of comparability quotient of these types is from 0.506 to 0.922, with an average 0.617. Furthermore, according to comparability quotient, set up UPGMA dendrogram, most of the species and their varieties or forms of Zanthoxylum clustered together and it showed that the relative relationship within species is nearer than that among species, and was accordance with the traditional taxa result. But there was obvious difference in relationship between Z. ovalifolium v. spinifolium which belong to Subgen. Fagara. This result is coherent to the quantity taxa by morphological characters.3 The system taxonomy analysis of ZanthoxylumThe guideline of traditional taxonomy is according to the differentiation between calyx and petals. On this basis the species which shows the differentiation between calyx and petal belongs to Subgen. Fagara. But the results in the present investigation showed that Z. ovalifolium v. spinifolium was more inclined to belong to Subgen. Of Zanthoxylum than belong to Sugen. Fagara, according to the results of numerical taxonomy and RAPD analysis, but taxonomy of the other species is coherent to the result of traditional taxonomy. Considering the morphological characters of every species and variation of Zanthoxylum, the genus Zanthoxylum can primarily be grouped into 5: 1) Sect. Bungeanum include Z. bungeanum, Z. armature and its variation, Z. acanthopodium v. timber, Z. piasezkii, Z. pilosulum.2) Sect. Dissitum include Z. dissitum and its variation.3) Sect. Macranthum include Z. ovalifolium, Z. ovalifolium v. spinifolium, Z. echinocarpum, Z. macranthum. 4) Sect. Leiboicum, only 1 species. 5) Sect. Micranthum include Z. esquirolii, Z. stenophyllum, Z. pashanense, Z. rhombifoliolatum, Z. cuspidatum and Z. micranthum.The results reflect that in traditional taxonomy, the partition of species which belong to Subgen. of Zanthoxylum is mainly according to the differentiation between calyx and petals and separated character of the style of female flower. The present studies used the method of quantitative taxonomy, and integrated lots of morphological characters of Zanthoxylum, so it overcame the localization of traditional taxonomy. Meanwhile, this research adopted the molecular technique of RAPD molecule marker to ensure the result of quantitative taxonomy.
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