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1.
Cladistic and phenetic analyses of the morphology of 79 species of Pogostemon Desf. sens lato have been undertaken. The cladistic analysis included 135 character state differences encoded as 41 binary or multistate characters. The phenetic analysis included 52 metric variables and 54 binary variables. There is a very good correspondence between the results of cladistic and phenetic analyses based on different data sets. The existence of several clearly marked clades/clusters has been demonstrated. Some groups/clades are similar to those previously taxonomically recognized but the relationships and membership of infra-generic groups have been clarified by these analyses, validating a revised infra-generic classification which has been proposed.  相似文献   

2.
Selectively amplified microsatellite polymorphic locus (SAMPL) analysis is a method of amplifying microsatellite loci using generic PCR primers. SAMPL analysis uses one AFLP primer in combination with a primer complementary to microsatellite sequences. SAMPL primers based on compound microsatellite sequences provided the clearest amplification patterns. We explored the potential of SAMPL analysis in lettuce to detect PCR-based codominant microsatellite markers. Fifty-eight SAMPLs were identified and placed on the genetic map. Seventeen were codominant. SAMPLs were dispersed with RFLP markers on 11 of the 12 main linkage groups in lettuce, indicating that they have a similar genomic distribution. Some but not all fragments amplified by SAMPL analysis were confirmed to contain microsatellite sequences by Southern hybridization. Forty-five cultivars of lettuce and five wild species of Lactuca were analyzed to determine the allelic diversity for codominant SAMPLs. From 3 to 11 putative alleles were found for each SAMPL; 2-6 alleles were found within Lactuca sativa and 1-3 alleles were found among the crisphead genotypes, the most genetically homogeneous plant type of L. sativa. This allelic diversity is greater than that found for RFLP markers. Numerous new alleles were observed in the wild species; however, there were frequent null alleles. Therefore, SAMPL analysis is more applicable to intraspecific than to interspecific comparisons. A phenetic analysis based on SAMPLs resulted in a dendrogram similar to those based on RFLP and AFLP markers.  相似文献   

3.
The amplified fragment length polymorphism (AFLP) method was used to evaluate genetic diversity and to assess genetic relationships within the section Mentha in order to clarify the taxonomy of several interspecific mint hybrids with molecular markers. To this end, genetic diversity of 62 Mentha accessions from different geographic origins, representing five species and three hybrids, was assessed. Three EcoRI/MseI AFLP primer combinations generated an average of 40 AFLP markers per primer combination, ranging in size from 50 to 500 base pairs (bp). The percentage of markers polymorphic ranged from 50% to 60% across all accessions studied. According to phenetic and cladistic analysis, the 62 mint accessions were grouped into two major clusters. Principal coordinates analysis separated species into well-defined groups, and clear relationships between species and hybrids could be described. Our AFLP analysis supports taxonomic classification established among Mentha species by conventional (morphological, cytological, and chemical) methods. It allows the assessment of phenetic relationships between species and the hybrids M. spicata and M. × piperita, largely cultivated all over the world for their menthol source, and provides new insights into the subdivision of M. spicata, based for the first time on molecular markers.  相似文献   

4.
Horizontal starch gel electrophoresis was employed to investigate allozyme variation at 19 isozyme loci, in nine closely-related Atlantic-Mediterranean gobiid fish species, to assess genetic relationships, and to compare this with a phyletic hypothesis based on morphological apo-morphies. The species examined were Gobius niger, G. auratus, G. cruentatus, G. paganellus, Mauligobius maderensis, Zosterisessor ophiocephalus, Thorogobius ephippiatus, Padogobius martensii and P. nigricans . Various phenetic and cladistic analyses were performed on isozyme and morphological data. The phenetic and cladistic results from morphological data, and the cladistic results from isozyme data, were largely comparable, with P. martensü and P. nigricans forming a sister group to all the other taxa, species of Cobius forming a crown group within the latter, and stem lines formed by Mauligobius, Zosterisessor and Thorogobius , respectively. The isozymic estimates of genetic distance differed from these chiefly in the relative positions of Zosterisessor and G. auratus , which appear less similar to other species of Gohius. G. auratus shows many alleles which are unique within the genus Gobius ; possible explanations for this are put forward. The position of nigricans as congeneric with Padogobius martensü is confirmed by both phenetic and cladistic analyses of isozyme data.  相似文献   

5.
Inferring phylogenetic relationships among closely related plant species is often difficult due to the lack of molecular markers exhibiting enough nucleotide variability at this taxonomic level. Moreover, gene tree does not necessary represent the true species tree because of random sorting of polymorphic alleles in different lineages. A solution to these problems is to use many amplified fragment length polymorphisms (AFLP) distributed throughout the whole genome, to infer cladistic and phenetic among-species relationships. Phylogenetic relationships among interfertile species of Trollius L. (Ranunculaceae) were investigated using nuclear DNA (ITS1+5.8S rRNA+ITS2) and chloroplast DNA (trnL intron and trnL-trnF intergene spacer) sequences, and AFLP markers. ITS sequences were not informative at the intrageneric level, but confirmed the sister relationship between Trollius and Adonis genera, and provided new information on the phylogenetic relationships among five Ranunculaceae genera. Chloroplast DNA was more informative among Trollius species, but not consistent with the sections previously described. AFLP proved to be a powerful tool to resolve the complex genetic relationships between the morphological entities constituting the genus Trollius. Although as much as 76.1% of the total AFLP variability was found within a priori defined morphological groups, the remaining 23.9% variability differentiating groups was sufficient to generate congruent and robust cladistic and phenetic trees. Several morphological traits, independent from those used to define groups, were mapped onto the molecular phylogeny, and their evolution discussed in relation to the absence/presence of pollinator-seed parasite Chiastocheta flies.  相似文献   

6.
Studies in the areas of comparative morphology and palynology of the genus Cyclamen L. (Primulaceae) are outlined, and used in combination with observations and analyses of past works and publications and of field data (gathered by the Cyclamen Society and others) to generate new data sets. These are subject to cladistic parsimony analysis for the entire genus, and to phenetic ordinal analysis for subgenus Gyrophoebe O.Schwarz, to reach a conclusion on the validity of the latter classification, and the separation of taxa within it. A phylogeny and subgeneric reclassification is proposed with the reinstatement of Cyclamen elegans Boiss. & Buhse at species level based on the results gathered. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 138 , 473–481.  相似文献   

7.
AFLP markers were evaluated for determining the phylogenetic relationships Lactuca spp. Genetic distances based on AFLP data were estimated for 44 morphologically diverse lines of cultivated L. sativa and 13 accessions of the wild species L. serriola, L. saligna, L. virosa, L. perennis, and L. indica. The same genotypes were analyzed as in a previous study that had utilized RFLP markers. The phenetic tree based on AFLP data was consistent with known taxonomic relationships and similar to a tree developed with RFLP data. The genetic distance matrices derived from AFLP and RFLP data were compared using least squares regression analysis and, for the cultivar data, by principal component analysis. There was also a positive linear relationship between distance estimates based on AFLP data and kinship coefficients calculated from pedigree data. AFLPs represent reliable PCR-based markers for studies of genetic relationships at a variety of taxonomic levels.  相似文献   

8.
In this study, in addition to the karyotype analysis, the chromosomal distributions of 5 S and 18 S rDNAs, and the Arabidopsis-type (T3AG3) telomeric sequences were detected by means of fluorescence in situ hybridization (FISH) to promote the information of chromosomal organization and evolution in the cultivated lettuce and its wild relatives, L. sativa, L. serriola, L. saligna and L. virosa. The karyotype analysis revealed the dissimilarity between L. virosa and the remaining species. In all four Lactuca species studied, one 5 S rDNA and two 18 S rDNA loci were detected. The simultaneous FISH of 5 S and 18 S rDNAs revealed that both rDNA loci of L. sativa, L. serriola and L. saligna were identical, however, that of L. virosa was different from the other species. These analyses indicate the closer relationships between L. sativa/L. serriola and L. saligna rather than L. virosa. Arabidopsis-type telomeric sequences were detected at both ends of their chromatids of all chromosomes not in the other regions. This observation suggests the lack of telomere-mediated chromosomal rearrangements among the Lactuca chromosomes.  相似文献   

9.
Using the AFLP technique highly informative DNA fingerprints were generated from 19 taxa ofSolanum sect.Petota (potatoes) and three taxa ofSolanum sect.Lycopersicum (tomatoes). Both phenetic and cladistic analyses were conducted from the individual genotypic level to the species level. An AFLP fingerprint, using a combination of suitable AFLP primers, generated 12 to 71 scorable fragments per genotype which was sufficient for taxonomic interpretation. The classifications based on the molecular markers were generally in agreement with current taxonomic opinions. Unexpectedly,S. microdontum was associated with ser.Megistacroloba rather than with ser.Tuberosa, andS. demissum (ser.Demissa) and species of ser.Acaulia appeared closely affiliated. AFLP is an efficient and reliable technique to generate biosystematic data and therefore a promising tool for evolutionary studies.  相似文献   

10.
Bacillus anthracis causes anthrax and represents one of the most molecularly monomorphic bacteria known. We have used AFLP (amplified fragment length polymorphism) DNA markers to analyze 78 B. anthracis isolates and six related Bacillus species for molecular variation. AFLP markers are extremely sensitive to even small sequence variation, using PCR and high-resolution electrophoresis to examine restriction fragments. Using this approach, we examined ca. 6.3% of the Bacillus genome for length mutations and ca. 0.36% for point mutations. Extensive variation was observed among taxa, and both cladistic and phenetic analyses were used to construct a phylogeny of B. anthracis and its closest relatives. This genome-wide analysis of 357 AFLP characters (polymorphic fragments) indicates that B. cereus and B. thuringiensis are the closest taxa to B. anthracis, with B. mycoides slightly more distant. B. subtilis, B. polymyxa, and B. stearothermophilus shared few AFLP markers with B. anthracis and were used as outgroups to root the analysis. In contrast to the variation among taxa, only rare AFLP marker variation was observed within B. anthracis, which may be the most genetically uniform bacterial species known. However, AFLP markers did establish the presence or absence of the pXO1 and pXO2 plasmids and detected 31 polymorphic chromosomal regions among the 79 B. anthracis isolates. Cluster analysis identified two very distinct genetic lineages among the B. anthracis isolates. The level of variation and its geographic distribution are consistent with a historically recent African origin for this pathogenic organism. Based on AFLP marker similarity, the ongoing anthrax epidemic in Canada and the northern United States is due to a single strain introduction that has remained stable over at least 30 years and a 1,000-mile distribution.  相似文献   

11.
Having mixed extremely various patterns of achenes for a long time in the genus Lactuca L., especially showed in the classification of it on the mainland of Asia, Lactuca L., the primary unnatural genus, becomes more nuclear in its limit. The present paper makes a revision to attempt providing a clear cline between Lactuca L. and its relative genera. On my opinion, only plants, represented by Lactuca sativa L., which have ovoid capitulum during its fruiting, numerous (7-25), yellow ligular florets and longitudinal 1-10 ribs or striae on each side of achenes, acute into filiform beak at its apex, should be defined as Lactuca L. In view of the present concept of Lactuca L., another group of plants, embodied by Lactuca indica L., having its broadening, thin winged-margin of, 1-3 striae on each side of achenes, black, dorsi-ventral compressed, acute into thick and short beak at its apex, evidently, should not be placed into Lactuca L., but be regarded as genus, i.e. Pterocypsela Shih, gen. nov. Pterocypsela Shih distributes in Eastern and southern Asia, where Lactuca L. does not occur. In China there is all of species, seven species, of Pterocypsela Shih. They are P. raddeana (Maxim.) Shih, P. indica (L.) Shih, P. elata (Hemsl.) Shih P. lacciniata (Houtt.) Shih, P. triangulata (Maxim.) Shih, P. sonchus (Lévl.) Shih and P. formosana (Maxim.) Shih, But in Mediterranean regions and Middle and Western Asia mainly distributes Lactu ca L., in which there are only seven species from western China, Xijiang autonomic district. They are L. dolichophylla Kitam., L. sativa L., L. altaica Fisch. et Mey., L. serriola Torner, L. dissecta Don, L. auriculata DC. and L. undulata Ledb. With the combination of violet-purple ligular florets non-ovoid capitulum during its fruiting, a little thick achenes, acuminate into longer. or short beak at its apex and 4-6 ribs on each side of it, Mulgedium tataricum (L.) DC. is evidently different from Lactuca sativa L. with combination of ovoid capitulum during its fruiting, yellow ligular florets and compres sed achenes, acute into filiform beak at its apex. There seems to be no point in refusing Mu lgedium Cass. as a genus. Strictly speak, Mulgedium Cass. seems to be reminiscent of Para prenanthes Chang (see bellow) without beak at the apex of its achenes. In Hengduan moun tains and mountain range of Himalayas M. tataricum (L.) DC. discoveries its relative par tners. They are M. bracteatum (Mook. f. ex. C. B. Clarke) Shih, M. lessertianum (Wall. ex C. B. Clarke) DC., M. monocephalum (Chang) Shih, M. umbrosum (Dunn) Shih, M. meridionale Shih and M. polypodifolium (Franch.) Shih. Having broadering and thickening margin and 4-7 striae on each side of achenes, grey, dorsi-ventral compressed, truncate and beakless at its apex, Lactuca sibirica (L.) Benth. ex Maxim. (Sonchus sibiricus L.) is not only different from Lactuca sativa L. with the combination of yellow ligular florets and filiform beak at apex of its achenes, but also from the genus Mulgedium Cass. with beak at apex of its achenes. Therefore, Lagedium Sojak, established by J. Sojak (1961), should be restored. It should be point out that Lagedium Sojak is monotypic genus excluding Mulgedium tataricum (L.) DC. with beak at the apex of its achenes, non-marginated. Lagedium Sojak widely distributes in temperate and frigid zone ofvnorthern hemisphere. In our country, Lagedium sibiricum (L.) Sojak, sole species of the genus, restricts its northeast region. Paraprenanthes Chang, the new genus, established by Ch. Ch. Chang (1950) based on Lactuca sororia Miq. and Lactuca yunnanensis Franch. seems to be a distinct genus. This genus is characterized by 4-6 ribs on each side of achenes, black, fusiform, a little thick and beakless at its apex. Besides above-mentioned two species, assigned by Chang, in forest of tropic and subtropic zones on the mainland of Asia there are many species with same structure in achenes like L. sororia Miq. and L. yunnanensis Franch. The genus Paraprenanthes Chang seems to be reminiscants of Mulgedium Cass. and Lagedium Sojak, but differs from the former in its beakless achenes, from the later in its non-marginated achenes and 4-6 ribs on each side of it. In our country, there are all species of the genus known in the tropic and subtropic zones on the mainland of Asia. They are P. sororia (Miq.) Shih, P. yunnanensis (Franch.) Shih, P. longiloba Ling et Shih, sp. nov., P. heptontha Shih et D. J. Liou, sp. nov., P. prenanthoides (Hemsl.) Shih, P. pilipes (Migo) Shih, P. thirionii (Lévl.) Shih, P. sylvicola Shih., sp. nov., P. multiformis Shih, sp. nov., P. auriculiformis Shih, sp. nov. and P. sagittiformis Shih, sp. nov.  相似文献   

12.
The evolution of five island populations of Green gecko, representing inter- and intra-specific divergence, was studied using biochemical data, scalation and shape. The data were numerically analysed using ordination analyses for the phenetic classification and Wagner trees to hypothesize the phylogeny. These studies revealed three phenetic groups corresponding to three mono-phyletic lineages. The numerical analysis of morphological data agreed with the numerical analysis of biochemical data. It is concluded that the classification based on biochemical affinities differed from the previous classification based on conventional analysis of morphology due to methodological and philosophical differences rather than differences between morphological and biochemical evolution.
The ordination analyses were very congruent between data sets (biochemical, shape, scalation, total) and the Wagner trees were generally congruent between data sets. Some Wagner trees based on scalation data were incongruent. The phenetic and cladistic classifications corresponded to each other but differed from the conventional classification. The phylogenetic analysis of the total data set indicated that the three specific lineages showed relatively equal anagenesis. However, anagenic divergence differed markedly between character types. It is suggested that a range of character types be used when studying anagenesis.  相似文献   

13.
The subfamilies and tribes of the family Bovidae   总被引:7,自引:0,他引:7  
In this paper 112 skeletal characters in 27 living species of bovids are used in cladistic and phenetic analyses of the relationships among the tribes in the family. Consideration and modification of the cladistic analysis leads to the conclusion that bovids cluster around four foci in ascending evolutionary sequence: Boselaphini and allies; Antilopini and some Neotragini; the Caprinae; and a group of African antelopes containing Aepyceros , Alcelaphini, Reduncini and Hippotragini. This conclusion is quite closely compatible with the phenetic distance analysis of the same data, provided die latter is read as if primitive or early bovids share more similarities than divergently advanced ones and hence associate more closely. Given the primitiveness of Boselaphini and allies, the crucial finding is that Caprinae link with African antelopes and that Antilopini are more remote. Cladistic and phenetic analyses of 32 characters in 12 extinct bovid species produce similar groupings, but also throw doubt on the classification of Aepyceros , Reduncini and Hippotragini alongside Alcelaphini within a clade of African antelopes. As a result of these two sets of studies, of living and of extinct bovids, minimal alterations are proposed to the arrangement of bovid tribes. In addition, Saiga is placed in the Antilopini, and, with less assurance, Pelea in the Neotragini, Aepyceros in the Alcelaphinae, and Pantholops in the Caprinae. The contribution of the fossil record to understanding bovid evolution is considered.  相似文献   

14.
Improving commercial utilization of perennial Medicago collections requires developing approaches that can rapidly and accurately characterize genetic diversity among large numbers of populations. This study evaluated the potential of using amplified fragment length polymorphism (AFLP) DNA markers, in combination with DNA bulking over multiple genotypes, as a strategy for high-throughput characterization of genetic distances (D) among alfalfa (Medicago sativa L.) accessions. Bulked DNA templates from 30 genotypes within each of nine well-recognized germplasms (African, Chilean, Flemish, Indian, Ladak, Medicago sativa subsp. falcata, Medicago sativa subsp. varia, Peruvian, and Turkistan) were evaluated using 34 primer combinations. A total of 3754 fragments were identified, of which 1541 were polymorphic. The number of polymorphic fragments detected per primer combination ranged from 20 to 85. Pairwise D estimates among the nine germplasms ranged from 0.52 to 1.46 with M. sativa subsp. falcata being the most genetically dissimilar. Unweighted pair-group method arithmetic average (UPGMA) analysis of the marker data produced two main clusters, (i) M. sativa subsp. sativa and M. sativa subsp. varia, and (ii) M. sativa subsp. falcata. Cluster-analysis results and D estimates among the Chilean, Peruvian, Flemish, and M. sativa subsp. varia germplasms supported the hypothesis that Peruvian was more similar to original Spanish introductions into Central and South America than Chilean. Hierarchical arrangement of the nine germplasms was supported by their respective geographic, subspecific, and intersubspecific hybrid origins. Subsets of as few as seven highly informative primer pairs were identified that produced comparable D estimates and similar heirarchical arrangements compared with the complete dataset. The results indicate that use of primer-pair subsets for AFLP analysis of bulk DNA templates could serve as a high-throughput system for accurately characterizing genetic diversity among large numbers of alfalfa populations.  相似文献   

15.
A set of 61 simple sequence repeat (SSR) markers was developed from the 19,523 Lactuca sativa and Lactuca serriola unigenes. Approximately 4.5% of the unigenes contained a perfect SSR at least 20 bp long, corresponding to roughly 1 perfect SSR per 14.7 kb. Marker polymorphism was tested on a set comprising 96 accessions representing all major horticultural types and 3 wild species (L. serriola, Lactuca saligna, and Lactuca virosa). Both the average marker heterozygosity (UHe = 0.32) and the number of different alleles per locus (Na = 3.56) were significantly reduced in expressed sequence tag (EST)-SSRs as compared with anonymous SSRs (UHe = 0.59, Na = 5.53). Marker transfer rate to the wild species corresponded to the decreasing sexual compatibility with L. sativa and was higher for EST-SSRs (100% L. serriola, 87% L. saligna, and 75% L. virosa) than for anonymous SSRs (93%, 66%, and 42%, respectively). Assessment of population structure among 90 L. sativa cultivars with SSRs was in good agreement with classification into the horticultural types. The average marker heterozygosity was smallest in iceberg (0.097), Latin (0.140), and romaine-type (0.151) cultivars while highest in leaf (green leaf 0.208 and red leaf 0.240) lettuces. The level of marker heterozygosity is in accord with morphological variability observed in different horticultural types.  相似文献   

16.
G S Buso  P H Rangel  M E Ferreira 《Génome》2001,44(3):476-494
A sample of American wild rice and other accessions of the genus Oryza were studied at polymorphic regions of nuclear, mitochondrial, and chloroplastic genomes. First, flow cytometry, genome-specific RAPD markers, and chromosome counting were utilized to verify the original ploidy and classification of 230 accessions studied. Based on these methods, 8% of the accessions were considered to be misclassified either taxonomically or as a result of contamination. Second, a fine resolution analysis was conducted at genomic regions sampled at random by RAPD markers and at specific sites of the chloroplast and mitochondrial DNA by cleaved amplified polymorphic sequence (CAPS) analysis. Phylogenetic trees resulting from phenetic and cladistic analyses of RAPD, cpDNA, and mtDNA polymorphisms were obtained. The results indicated that the American diploid species O. glumaepatula should be considered an individual species, distinct from O. rufipogon, and confirmed that the American tetraploid species (O. alta, O. grandiglumis, and O. latifolia) belong to the O. officinalis complex. The data indicate that these species should still be treated as a group rather than as three distinct species and that their closest relative is a CC-genome species. It was estimated that the diploid and tetraploid American species diverged from O. sativa - O. nivara (AA genome) and CC- and BBCC-genome species, respectively, 20 million years ago.  相似文献   

17.
The Sequence-Specific Amplification Polymorphism (S-SAP) method, recently derived from the Amplified Fragment Length Polymorphism (AFLP) technique, produces amplified fragments containing a retrotransposon LTR sequence at one end and a host restriction site at the other. We report the application of this procedure to the LTR of the Tms1 element from Medicago sativa L. Genomic dot-blot analysis indicated that Tms1 LTRs represent about 0.056% of the M. sativa genome, corresponding to 16 x 10(3) copies per haploid genome. An average of 66 markers were amplified for each primer combination. Overall 49 polymorphic fragments were reliably scored and mapped in a F(1) population obtained by crossing diploid M. falcata with M. coerulea. The utility of the LTR S-SAP markers was higher than that of AFLP or SAMPL (Selective Amplification of Microsatellite Polymorphic Loci) markers. The efficiency index of the LTR S-SAP assay was 28.3, whereas the corresponding values for AFLP and SAMPL markers were 21.1 and 16.7, respectively. The marker index for S-SAP was 13.1, compared to 8.8 for AFLP and 9.5 for SAMPL. Application of the Tms1 LTR-based S-SAP to double-stranded cDNA resulted in a complex banding pattern, demonstrating the presence of Tms1 LTRs within exons. As the technique was successfully applied to other species of the genus Medicago, it should prove suitable for studying genetic diversity within, and relatedness between, alfalfa species.  相似文献   

18.
Internal transcribed spacer (ITS-1) sequences from 97 accessions representing 23 species of Lactuca and related genera were determined and used to evaluate species relationships of Lactuca sensu lato (s.l.). The ITS-1 phylogenies, calculated using PAUP and PHYLIP, correspond better to the classification of Feráková than to other classifications evaluated, although the inclusion of sect. Lactuca subsect. Cyanicae is not supported. Therefore, exclusion of subsect. Cyanicae from Lactuca sensu Feráková is proposed. The amended genus contains the entire gene pool (sensu Harlan and De Wet) of cultivated lettuce (Lactuca sativa). The position of the species in the amended classification corresponds to their position in the lettuce gene pool. In the ITS-1 phylogenies, a clade with L. sativa, L. serriola, L. dregeana, L. altaica, and L. aculeata represents the primary gene pool. L. virosa and L. saligna, branching off closest to this clade, encompass the secondary gene pool. L. virosa is possibly of hybrid origin. The primary and secondary gene pool species are classified in sect. Lactuca subsect. Lactuca. The species L. quercina, L. viminea, L. sibirica, and L. tatarica, branching off next, represent the tertiary gene pool. They are classified in Lactuca sect. Lactucopsis, sect. Phaenixopus, and sect. Mulgedium, respectively. L. perennis and L. tenerrima, classified in sect. Lactuca subsect. Cyanicae, form clades with species from related genera and are not part of the lettuce gene pool.  相似文献   

19.
D-H Kim  D Heber  D W Still 《Génome》2004,47(1):102-111
The taxonomy of Echinacea is based on morphological characters and has varied depending on the monographer. The genus consists of either nine species and four varieties or four species and eight varieties. We have used amplified fragment length polymorphisms (AFLP) to assess genetic diversity and phenetic relationships among nine species and three varieties of Echinacea (sensu McGregor). A total of 1086 fragments, of which approximately 90% were polymorphic among Echinacea taxa, were generated from six primer combinations. Nei and Li's genetic distance coefficient and the neighbor-joining algorithm were employed to construct a phenetic tree. Genetic distance results indicate that all Echinacea species are closely related, and the average pairwise distance between populations was approximately three times the intrapopulation distances. The topology of the neighbor-joining tree strongly supports two major clades, one containing Echinacea purpurea, Echinacea sanguinea, and Echinacea simulata and the other containing the remainder of the Echinacea taxa (sensu McGregor). The species composition within the clades differs between our AFLP data and the morphometric treatment offered by Binns and colleagues. We also discuss the suitability of AFLP in determining phylogenetic relationships.  相似文献   

20.
Phenetic and cladistic relationships among tenebrionid beetles (Coleoptera)   总被引:4,自引:0,他引:4  
Abstract. The higher classification of Tenebrionidae is analysed using numerical phenetic, numerical cladistic and traditional Hennigian methods. In all, eighty characters are examined for about 335 taxa; definitive analyses are made on combinations of eighteen to seventy characters for thirty-three OTUs. At lower levels of relationship (genera and closely related tribes) phenetic and cladistic classifications are shown to be congruent, but at higher levels (tribes and subfamilies) there is marked discordance with phenetic results being more stable. A consensus classification is more similar to the Hennigian cladogram than is any single computer generated cladogram. Two main tribal groups – the Lagrioid and Tenebrionoid groups – are suggested which differ in defensive glands, female anatomy, wing and mouthpart morphology, larval characters and other features. The Tenebrionoid group consists of three main subdivisions – the tenebrionine, coelometopine and diaperine lineages. Changes in classificatory position are recommended for eighty-seven genera and tribes (listed in Appendix E) and implied for numerous others.  相似文献   

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