Systematic Of Genus Angelica L. In South West China

Southwest China is one of the distribution centers of Angelica L., so thesystematic and taxonomic study on Southwest China's Angelica species has a greatsignificance. Previous studies were reviewed and lab work was carried out in thisresearch in terms of anatomical characteristics, pollen morphology, karyotype andmolecular systematics. Geographic distribution of Angelica in Southwest China wasalso analyzed.All the Angelica fruits are dorsal compressed, in most cases the valleculae ofdorsal rib each has only 1 vittae (occasionally 2) and the concrescence has two(occasionally 3-6). Their aliform lateral ribs may be equal to or wider than the fruititself but in some cases narrower. Different species show different endospermcharacteristics. Thus, the anatomical characteristics of fruits might serve asreferences in revealing the interspecific relationship within Angelica.Chromosome number of Southwest China's Angelica species is invariably2n=2x=22, with most chromosomes median and submedian centromeric, andsubterminal centromeric chromosomes were observed in A. omeiensis. The majorityof karyotypes belong to 2A, and some populations of A. laxrfoliata have 1A type.These distinct interspecific differences of chromosomal morphology provideimportant evidences for classification of Angelica.Pollen grains of Southwest China's Angelica plants are big and distinctlydifferentiated, with diverse types ranging from primitive ones to medium andadvanced ones. Pollen shapes are mainly sub-rhombus, oval, sub-rectangle and equator-constricted, aperture angulaperturate or lateral aperture. The diversity ofpollen type indicates that Angelica in Southwest China has an early origin and hasbeen evolving all the while. Therefore, pollen characters are also importantevidences for the classification of this genus.ITS gene of 3 Angelica species were sequenced and analyzed together with theexisting molecular data in NCBI GenBank. Phylogeny of this genus wasreconstructed with maximum parsimony and maximum likelihood methods inPAUP4.0 respectively.As a genus belongs to temperate zone, Angelica L. mostly distributes inNorth America and East of Asia. China is the first in Asia in terms of abundance andthere are two richness centers in this country, i.e. Besides Sino-Japan forestsubkingdom, the most dominantfloristic composition of Angelica L. isSino-Himalaya forest subkingdom. Because ofthe diversification in morphology,pollen characteristics, karyotype, and so on, as wellas the abundance of Angelica L.in this region, we think that East Asia is one of the richness centers, origin centersand diversity centers.A comprehensive analysis of morphological characters was made with cladisticmethod using PAUP4.0. Primitive characters of China's Angelica were concluded, and the interspecific relationship within the genus was further discussed with theresult of molecular phylogeny combined.Based on above analyses, Angelica L. is devided into 5 sections: Sect.Paucifoliata, Sect. Plurivittata, Sect. Angustialae, Sect. Latialae and Sect. Angelica.Sect. Angelica is the most advanced group of the genus. As for A. apaensis, itdistinctly differs from the other species of Angelica L. in the characteristics of petalsand fruits, pollen morphological features as well as characteristics of leaf epidermis.Futhermore, evolution of these features is not simultaneous, so it's rather difficult tomake certain treatment of its taxonomical status and further researth work isexpected.