Studies On The Systematic Classification Of Three Saussurea Species Distributing In The Qinghai-tibetan Plateau

Saussurea DC. of Trib. Cynarea of Compositae is a large genus in the northtemperate zone distributing. All over the world, about415species, Asia temperatemountain region is the most abundant biodiversity areas, especially in the Siberia, theHimalayas and the Qinghai-tibet plateau in central Asia region. distribute in China289species, including endemic species in191, general distributing in high latitudesand high altitude areas in China such as the Tibetan plateau and tianshan, thehengduan mountains, Himalayas. Saussurea DC. in Gansu mainly distributed inGannan, Qilian cold area, there are57species and1variant, which accounts for22%of the total of the species in Saussurea. Hezuo, Xiahe, Maqu etc.of Gansu haveabundant Saussurea plants. Some of them have higher medicinal value. The studieson them have very important academic and application significance.In this part, S. acroura, S. parviflora, S. variiloba were chosen as researchmaterial. The level of morphology (description of the plant organs, and measurement),organ level (leaf anatomical shape feature), a cellular level (chromosome number andkaryotype analysis observation) were used to study the three kinds of Saussurea. It isthe first time to study the karyotype analysis of S. acroura. The results provide atheoretical basis for the system evolution, taxon system position of Saussurea. whichhas important significance in solving Saussurea within the genus taxon systemlocation. And also those results provide important evidence for the determination ofthis genus hybrid speciation mechanisms. The main results are listed as follows:1. Most of S. acroura’s morphological characteristics and characteristics of leafanatomical structure is between S. parviflora’s and S. variiloba’s, S. acroura hasobvious advantages in the individual characters.2. The chromosome numbers of3species of Saussurea is2n=26. They are all diploid.And the karyotype formulae are as follows: S. acroura2n=2x=26=14m+10sm+2st,karyotype belongs to stebbings2B type; S. parviflora2n=2x=26=16m+8sm+2st,karyotype belongs to stebbings2B type; S. variiloba2n=2x=26=10m+12sm+4st,karyotype belongs to stebbings3A type. No satellites have been found in these3 species.3. According to the result of the karyotype analysis and the result of the clusteranalysis tree of Saussurea that S. acroura and S. parviflora having closerrelationship, S. parviflora and S. variiloba having the farther relationship; and S.acroura and S. parviflora are more evolver than S. variiloba. This result andtraditional classification of Saussurea is not consistent.4. S. acroura maybe is a putative hybrid species of S. parviflora and S. variiloba.