Systematic Of Genus Peucedanum In Southwese Of China

Peucedanum L. belongs to Apioideae and Peucedaneae comprises ca. 130 species mainly distributed in global. More than 30 species occur in China and about 18 species 1 varietis mainly distributed in southwest of china. In peucedanum L.,the relationship between species is very complex and many species position in peucedanum is unclear.we hoped that we can comprehend the genesis and evolution of peucedanum L.From my research. At the same time we hope to afford other researcher more evidence to study peucedanum L.My reseach include Pollen morphology ,Molecular Systematics, Cytotaxonomy and morphology of the leaf epidermis.In my study,Micromorphological characters of leaf epidermis of 6 species of Peucedanum were examined by LM. The main conclusions are as follows: no capill exeist on the surface of leaf of all 6 species; The shape of epidermal cells with the nearly straight or sinuolate or sinuate pattern of anticlinal wall was generally irregular ,sometimes polygonal; The Stomatal apparatus of 5 species of Peucedanum, restricted to adaxial and abaxial epidermis ,was assigned to paracytic type and irregular .The shape of the guard cell is ellipse,subround or irregular.The sequences of the ITS regions and 5.8S and trnL-trnF coding region of nuclear ribosomal DNA from the genus Peucedanum were determined . Based on the ITS sequences of Peucedanum and its Related Genera,the phylogeny of Peucedaneae Drude was reconstructed. It was shown that does Peucedanum exhibit close affinity with Angelica .the position of Ferula in Peucedaneae Drude is not definitive. Peucedanum exhibit close affinity with Phlojodicarpus; Arcuatopterus Sheh et Shan exhibit distant affinity with Peucedanum. Classification in the internal Peucedanum need further study. the position of P. dissolutum in Peucedanum is not definitive. P. japonicum should be segregated from Sect. Bracteolata Shan et Sheh of Peucedanum .Pollen morphology of 6 species of the genus Peucedanum was investigated. Pollen grains of all the species were examined by LM and SEM. The study showed that pollen grains of Peucedanum in vary shape. Their framework was trigonal in solid form. Tricolporate pleurotreme and exine 2-lauered. The statification of exine was clear. According to the characteristics of the pollen grains in Peucedanum,it may be divided into clearly distinguished types Rectangular type and Equatorially→constricted type. Pollen information supports that Peucedanum as an advanced taxon in Umbelliferae. The trendency of evolution in Peucedanum is that: the size of pollen is from gig to small; equater is from straight to contractus. According to pollen information ,sect. Bracteolata shoud be a comparatively primitive taxon.The chromosome numbers or and karyotypes of two species of genus Peucedanum and three populations of Notopterygium forbesii in Umbelliferae are studied.. Among them, the somatic chromosome numbers and karyotypes of two species of Peucedanum are reported for the first time. The chromosome numbers of all species are 2n=22. The karyotype of Peucedanum turgeniifolium only consists of metacentric chromosomes and Peucedanum songpanense consists of metacentric and submetacentric chromosomes. All the chromosomal numbers and karyotypes were first reported here.Cladistics is the current method to settle the relationship of phylogenesis. In this article, 16 operational maximum units (OTUS)of Peucedanum L. from southwest of China were studied by means of cladistic analysis so as to understand the phylogenetic relation ship of Peucedanum L.The result support the segregation of Peucadanum japonicum from Peucedanum L. Peucadanum japonicum formed the Sect japonicum xingjin he et zhang xuemei.The 18 species 1 varietis in southwest of china mainly distribute in the altiplano of West of Sichuan in 200-3000m. The areal-type of Peucedanum L. is Old World Temperate. Besides Sino-Japan forest subkingdom, the most dominant floristic composition of Ligusticum L. is Sino-Himalaya forest subkingdom, especially Hengduan Mountains. Combined with the diversification in morphology, pollen characteristics, and the anatomical characteristics of petioles and so on, as well as abundance of Peucedanum L. in this region, we think that Hengduan Mountains and Central China is the richness centers and diversity centers.Based mainly on morphological characteristics, especially the characters of involucel bracteoles and mericarps, combined with reference to cladistic analysis results and the results of experiments, a conclusion is that Peucedanum L. in southwest can be divided into the following 5 sections.P.japonicum formed a new stct.P.dissolutum segregated from Sect.Selinoides DC. and concluded in sect. Bracteolata Sheh et Shan. In the end of the thesis, I give everyone a key to species and simple discription of species in Southwese of China.