-
[show abstract]
[hide abstract]
ABSTRACT: We examined 15 species of the genus Ligusticum (Apiaceae) from China using LM (light microscopy) and SEM (scanning electron microscopy). Different species have irregular and polygonal epidermal cells and four different stomatal types. Almost all species have different types of stomata on the same leaf surface. Ridges and striations on the cuticular membrane are common features in Ligusticum, and special striation papillae are found in three species. Regarding its epidermal characters, Ligusticum is not supported as a natural genus. Tilingia is suggested as being restored from Ligusticum. The monophyly of Ligusticopsis is not supported and it cannot be segregated from Ligusticum by epidermal characters. We confirm a very close relationship between Ligusticum and Conioselinum and discuss some of the valuable taxonomic characters of Ligusticum.
Annales Botanici Fennici 01/2012; · 1.01 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In this paper, karyotype data of the tribe Lilieae in China were analyzed and been superimposed onto a phylogenetic framework constructed by the internal transcribed spacer to investigate the karyotype evolution. Ten parameters for analyzing karyotype asymmetry were assessed and karyotypic idiogram of five genera of Lilieae were illustrated. The results showed that, the relationship of genera in Lilieae that inferred from Maximum Parsimony criteria and Bayesian Inference were congruent with previous studies, which focused on higher level of Liliales. The karyotype showed distinctive among genera, mainly expressed on the location and amount of secondary constrictions and intercalary satellites: the genus Notholirion have neither of them, and the genera Cardiocrinum and Fritillaria have the secondary constriction alone; the genera Lilium and Nomocharis showed both features, and the distribute pattern of the intercalary satellites showed similarity among related clades. The asymmetry that assessed by several methods indicated that the evolution trend of Lilieae did not follow a single direction, but different in each genus. On the sectional level of the genus Lilium (including Nomocharis) the karyotype evolution included three major periods. Combining the chromosomal structure variations and karyotype asymmetry, the chromosome diversity and evolution in Lilieae were quite clear in the light of molecular inference.
Journal of Plant Research 05/2011; 125(1):55-69. · 1.75 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The genus Allium comprises more than 800 species, placing it among the largest monocotyledonous genera. It is a variable group that is spread widely across the Holarctic region. Previous studies of Allium have been useful in identifying and assessing its evolutionary lineages. However, there are still many gaps in our knowledge of infrageneric taxonomy and evolution of Allium. Further understanding of its phylogeny and biogeography will be achieved only through continued phylogenetic studies, especially of those species endemic to China that have often been excluded from previous analyses. Earlier molecular studies have shown that Chinese Allium is not monophyletic, so the goal of the present study was to infer the phylogeny and biogeography of Allium and to provide a classification of Chinese Allium by placement of Chinese species in the context of the entire phylogeny.
Phylogenetic studies were based on sequence data of the nuclear ribosomal internal transcribed spacer (ITS) and chloroplast rps16 intron, analysed using parsimony and Bayesian approaches. Biogeographical patterns were conducted using statistical dispersal-vicariance analysis (S-DIVA).
Phylogenetic analyses indicate that Allium is monophyletic and consists of three major clades. Optimal reconstructions have favoured the ancestors of Amerallium, Anguinum, Vvedenskya, Porphyroprason and Melanocrommyum as originating in eastern Asia.
Phylogenetic analyses reveal that Allium is monophyletic but that some subgenera are not. The large genetic distances imply that Allium is of ancient origin. Molecular data suggest that its evolution proceeded along three separate evolutionary lines. S-DIVA indicates that the ancestor of Amerallium, Anguinum, Vvedenskya, Porphyroprason and Melanocrommyum originated from eastern Asia and underwent different biogeographical pathways. A taxonomic synopsis of Chinese Allium at sectional level is given, which divides Chinese Allium into 13 subgenera and 34 sections.
Annals of Botany 11/2010; 106(5):709-33. · 4.03 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Abstract In the present study, the karyotypes of 34 populations belonging to 11 species and one variety of Heracleum from the Hengduan Mountains in China were examined. Chromosome numbers and the karyotypes of three species (H. souliei, H. kingdoni, and H. wenchuanense) are reported for the first time, as are the karyotypes of H. moellendorffii and H. henryi (tetraploid). Populations of H. candicans, H. franchetii, and H. kingdoni in the Hengduan Mountains were found to consist of a mixture of diploid and tetraploid plants. Except for four species of Heracleum, namely H. candicans, H. franchetii, H. henryi, and H. kingdoni, which have both diploid and tetraploid karyotypes, all other species of Heracleum are were found to be diploid. All karyotypes were found to belong to the 2A type of Stebbins, with the exception of H. candicans var. obtusifolium, which belongs to 2B, and H. hemsleyanum and H. franchetii (Mt. Dujuan, Daocheng, Sichuan, China), which belong to 1A. There was only a slight difference in the karyotype asymmetry index, which suggests a close kinship for species of Heracleum and that the entire phylogenetic development of Heracleum is relatively primitive. Species that exhibited advanced morphological features were also more advanced in karyotype structure, with the order of karyotype evolution being 1A→2A→2B. This phenomenon indicates that the species distributed in the Hengduan Mountains have not diverged completely and that the Hengduan Mountains are a relatively young and active area for the evolution of Heracleum. Polyploidization in Heracleum may be an important evolutionary mechanisms for some species, generating diversity. The biological attributes, distribution range, and the geological history of the genus have all played a part in accelerating the evolution through polyploidization or aneuploidization. It is known that as the distribution latitude of Heracleum decreases from north to south, the chromosome number, ploidy level, and asymmetry structure appear to increase. In the Hengduan Mountains, these tendencies are also evident. Finally, based on all the available cytogeographic data, we speculate that the more advanced tetraplont or aneuploid species of Heracleum in India may be derived from early diplont species that were distributed in the Caucasus region and Hengduan Mountains. The dispersal of Heracleum was from Eurasia to India, because this correlates with the emergence of the Himalayan Mountains through tectonic movement. Thus, the Hengduan Mountains are not only a center of diversity for Heracleum, but also a center of active speciation in modern times.
Journal of Systematics and Evolution 07/2009; 47(4):273 - 285. · 1.60 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Ligusticum L. consists of over 60 species which are widely distributed in Eurasia and North America, with 40 of these species found in China. This paper attempts to carry out a cladistic analysis on all 40 Chinese Ligusticum species and several species from the allies of Ligusticum, such as Selinum L, Conioselinum Fisch., and Cnidium Cuss. using their floral and vegetative morphological characters. The cladistic analysis does not support Ligusticum as a monophyletic genus. Instead, the 40 species are divided into five clades according to the MP (maximum parsimony) tree. With discussion revolving on each of the clades, Tilingia Regel is suggested to be restored, Ligusicopsis Leute is confirmed not to be a natural genus, and some useful clues about the relationship between Ligusticum, Selinum, and Conioselinum are discovered. The taxonomic significance and evolutionary trends of bracteoles and pollen grain characters are discussed.
Nordic Journal of Botany 03/2008; 26(1‐2):118 - 128. · 0.55 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Croton caudatus is an important species in Dai folk medicine. Some other Croton species, in particular, C. kongensis, C. cascarilloides, C. crassifolius, C. lachnocarpus and C. olivaceus are often marketed as C. caudatus, and thus, the therapeutic effects of C. caudatus are not achieved. The respective morphological features of the plants are similar, and they are not easy to distinguish morphologically from each other. In an attempt to find a method for discriminating among these species, we compared their nuclear ribosomal DNA internal transcribed spacer (ITS) region. Species-specific probes were derived from the ITS region of these species for species identification. This method provides effective and accurate identification of C. caudatus.
Planta Medica 07/2007; 73(6):611-3. · 2.15 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The ITS regions of Euphorbia pekinensis and six other Euphorbia species used as adulterants of E. pekinensis were sequenced to differentiate them. The sequences are identical among the individuals in the seven species studies. Diversity in DNA sequences among various species was found ranging from 8.3% to 43.8% in ITS1 and 7.6% to 36.6% in ITS2 region. Furthermore, based on the divergent ITS regions, species-specific primers, JDJp 1 and JDJp 2, were designed in the polymorphic regions of E. pekinensis to distinguish it from adulterants. These ITS-derived primers amplified a 281-bp-specific DNA fragment from E. pekinensis. No amplified product was observed using DNA of six adulterants.
Planta Medica 02/2007; 73(1):91-3. · 2.15 Impact Factor
