Genetic Diversity Of Zanthoxylum L. Resources

Zanthoxylum L. is a plant in the family Rutaceae. They are chiefly trees, small trees or woody vines; evergreen or deciduous. There are about 250 species widely distributed in Asia, Oceania, North America's tropical and subtropical regions. In China, there are 39 species and 14 varieties widely distributed. Zanthoxylum L. is a group of plants which have high economic value and abundant biodiversity and can be the forest for soil and water conservation. But the confused classification limited the breeding and spreading of Zanthoxylum L..On the theoretical basis of DNA genetic diversity ,this study aimed at screening the genetic diversity and genetic similarity of 45 Zanthoxylum L. samples colleted from 6 provinces in China,mainly by ISSR-PCR method together with morphological characters. The main results are as follows:1. To get high-quality DNA from young leaves of Zanthoxylum L.,the improved CTAB and SDS method were compared in this paper. The results showed that: SDS method can not effectively remove the polysaccharides and other small molecules from the samples. The improved CTAB method was the better method since the DNA extracted by it had the better A(260)/A(280) ratio and the better ISSR-PCR results.2. With 11 informative primers in ISSR analysis,there are 102 amplified bands in total, between 150bp-2000bp, 86 polymorphic bands,and polymorphic frequeccy is 84.31%. This results showed that samples had abundant biodiversity.3.The similarity of samples by ISSR marker was 0.4595-0.9189. The similarity and coefficient of variability of morphological quantitative characters was 0.4459-0.8784 and 14.7%-39.2% respectively. The results also indicated that samples had abundant biodiversity either in genetics or morphology.4. ISSR markers analysis showed that the samples have six groups. There are some differences among the samples of geographic distribution.5. By the 26 quantitative traits cluster,45 samples can be clustered 3 groups,not match to the species classification. For example,samples of the same specie were clustered to different groups. So classification by morphological marker has limitation and disadvantage according to the results.