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1.
MOLECULAR PHYLOGEOGRAPHY, RETICULATION, AND LINEAGE SORTING IN MEDITERRANEAN SENECIO SECT. SENECIO (ASTERACEAE) 总被引:1,自引:0,他引:1
Hans Peter Comes Richard J. Abbott 《Evolution; international journal of organic evolution》2001,55(10):1943-1962
Abstract The Mediterranean species complex of Senecio serves to illustrate evolutionary processes that are likely to confound phylogenetic inference, including rapid diversification, gene tree‐species tree discordance, reticulation, interlocus concerted evolution, and lack of complete lineage sorting. Phylogeographic patterns of chloroplast DNA (cpDNA) haplotype variation were studied by sampling 156 populations (502 individuals) across 18 species of the complex, and a species phylogeny was reconstructed based on sequences from the internal transcribed spacer (ITS) regions of nuclear ribosomal DNA. For a subset of species, randomly amplified polymorphic DNAs (RAPDs) provided reference points for comparison with the cpDNA and ITS datasets. Two classes of cpDNA haplotypes were identified, with each predominating in certain parts of the Mediterranean region. However, with the exception of S. gallicus, intraspecific phylogeographic structure is limited, and only a few haplotypes detected were species‐specific. Nuclear sequence divergence is low, and several unresolved phylogenetic groupings are suggestive of near simultaneous diversification. Two well‐supported ITS clades contain the majority of species, amongst which there is a pronounced sharing of cpDNA haplotypes. Our data are not capable of diagnosing the relative impact of reticulation versus insufficient lineage sorting for the entire complex. However, there is firm evidence that S. flavus subsp. breviflorus and S. rupestris have acquired cpDNA haplotypes and ITS sequences from co‐occurring species by reticulation. In contrast, insufficient lineage sorting is a viable hypothesis for cpDNA haplotypes shared between S. gallicus and its close relatives. We estimated the minimum coalescent times for these haplotypes by utilizing the inferred species phylogeny and associated divergence times. Our data suggest that ancestral cpDNA polymorphisms may have survived for ca. 0.4–1.0 million years, depending on molecular clock calibrations. 相似文献
2.
《Biochemical Systematics and Ecology》2002,30(4):309-319
The chloroplast gene matK and the internal transcribed spacer (ITS) regions of nuclear ribosomal DNA were sequenced from 17 samples of 13 species representing 6 genera of the angiosperm family Rhizophoraceae from China. Phylogenetic analyses were initially conducted based on sequences of the matK gene and the ITS regions, respectively, using Byrsonima crassifolia and Bunchosia armeniaca (Malpighiaceae) as outgroups. The partition–homogeneity test indicated that the two data sets are homogeneous. A combined analysis of the matK and ITS data generated a well supported phylogeny, which is topologically congruent with the two gene trees based on the Templeton test. The combined phylogeny shows that each genus formed a monophyletic group and the monophyletic relationships of the mangrove genera and of the inland genera were strongly supported. 相似文献
3.
Many species of Schisandraceae are used in traditional Chinese medicine and are faced with contamination and substitution risks due to inaccurate identification. Here, we investigated the discriminatory power of four commonly used DNA barcoding loci (ITS, trnH-psbA, matK, and rbcL) and corresponding multi-locus combinations for 135 individuals from 33 species of Schisandraceae, using distance-, tree-, similarity-, and character-based methods, at both the family level and the genus level. Our results showed that the two spacer regions (ITS and trnH-psbA) possess higher species-resolving power than the two coding regions (matK and rbcL). The degree of species resolution increased with most of the multi-locus combinations. Furthermore, our results implied that the best DNA barcode for the species discrimination at the family level might not always be the most suitable one at the genus level. Here we propose the combination of ITS+trnH-psbA+matK+rbcL as the most ideal DNA barcode for discriminating the medicinal plants of Schisandra and Kadsura, and the combination of ITS+trnH-psbA as the most suitable barcode for Illicium species. In addition, the closely related species Schisandra rubriflora Rehder & E. H. Wilson and Schisandra grandiflora Hook.f. & Thomson, were paraphyletic with each other on phylogenetic trees, suggesting that they should not be distinct species. Furthermore, the samples of these two species from the southern Hengduan Mountains region formed a distinct cluster that was separated from the samples of other regions, implying the presence of cryptic diversity. The feasibility of DNA barcodes for identification of geographical authenticity was also verified here. The database and paradigm that we provide in this study could be used as reference for the authentication of traditional Chinese medicinal plants utilizing DNA barcoding. 相似文献
4.
DNA barcoding is a useful tool to define operational taxonomic units based on standardized DNA regions. In this study, three chloroplast markers (rbcL, trnH-psbA and matK) and one nrDNA marker (ITS) were tested for species identification in Roscoea. The ITS and trnH-psbA regions showed high success rate of PCR amplification and bidirectional sequencing, as well as perfect discriminatory ability. On the contrary, rbcL possessed no genetic variation and matK was relatively difficult in PCR amplification and DNA sequencing. Combination of multiple markers greatly improved identification ability of DNA barcoding. ITS + trnH-psbA could effectively discriminate 90% species based on method of the Neighbor-Joining (NJ) tree. Awful PCR amplification and DNA sequencing of matK restricted its efficiency, although it showed rich genetic variability in Roscoea. Moreover, it might be more appropriate to treat Roscoea cautleoides var. pubescens as an independent species based on molecular data, namely R. pubescens Z. Y. Zhu. 相似文献
5.
T. E. Peretolchina Yu. S. Bukin T. Ya. Sitnikova D. Yu. Sherbakov 《Russian Journal of Genetics》2007,43(12):1400-1407
In gastropod mollusk Baicalia carinata Dybowski, 1875, sampled in different sites of the Lake Baikal, comparison of 81 sequences of internal transcribed spacer 1 (ITS1) located between the genes for 18S rRNA and 5.8S rRNA, and of 100 sequences of the fragment of mitochondrial DNA cytochrome-c-oxidase subunit 1 gene (CO1) was performed. Molecular phylogenetic analysis showed that the endemic mollusk species studied formed at least two distinct populations, Southwestern and Eastern. Statistical significance of the species subdivision into two populations was evaluated using the Mann-Whitney rank test. 相似文献
6.
Abhinandan Mani Tripathi Antariksh Tyagi Anoop Kumar Akanksha Singh Shivani Singh Lal Babu Chaudhary Sribash Roy 《PloS one》2013,8(2)
Background
DNA barcoding as a tool for species identification has been successful in animals and other organisms, including certain groups of plants. The exploration of this new tool for species identification, particularly in tree species, is very scanty from biodiversity-rich countries like India. rbcL and matK are standard barcode loci while ITS, and trnH-psbA are considered as supplementary loci for plants.Methodology and Principal Findings
Plant barcode loci, namely, rbcL, matK, ITS, trnH-psbA, and the recently proposed ITS2, were tested for their efficacy as barcode loci using 300 accessions of tropical tree species. We tested these loci for PCR, sequencing success, and species discrimination ability using three methods. rbcL was the best locus as far as PCR and sequencing success rate were concerned, but not for the species discrimination ability of tropical tree species. ITS and trnH-psbA were the second best loci in PCR and sequencing success, respectively. The species discrimination ability of ITS ranged from 24.4 percent to 74.3 percent and that of trnH-psbA was 25.6 percent to 67.7 percent, depending upon the data set and the method used. matK provided the least PCR success, followed by ITS2 (59. 0%). Species resolution by ITS2 and rbcL ranged from 9.0 percent to 48.7 percent and 13.2 percent to 43.6 percent, respectively. Further, we observed that the NCBI nucleotide database is poorly represented by the sequences of barcode loci studied here for tree species.Conclusion
Although a conservative approach of a success rate of 60–70 percent by both ITS and trnH-psbA may not be considered as highly successful but would certainly help in large-scale biodiversity inventorization, particularly for tropical tree species, considering the standard success rate of plant DNA barcode program reported so far. The recommended matK and rbcL primers combination may not work in tropical tree species as barcode markers. 相似文献7.
S.L. Talbot S. Wyllie-Echeverria D.H. Ward J.R. Rearick G.K. Sage B. Chesney R.C. Phillips 《Aquatic Botany》2006
We gathered sequence information from the nuclear 5.8S rDNA gene and associated internal transcribed spacers, ITS-1 and ITS-2 (5.8S rDNA/ITS), and the chloroplast maturase K (matK) gene, from Zostera samples collected from subtidal habitats in Monterey and Santa Barbara (Isla Vista) bays, California, to test the hypothesis that these plants are conspecific with Z. asiatica Miki of Asia. Sequences from approximately 520 base pairs of the nuclear 5.8S rDNA/ITS obtained from the subtidal Monterey and Isla Vista Zostera samples were identical to homologous sequences obtained from Z. marina collected from intertidal habitats in Japan, Alaska, Oregon and California. Similarly, sequences from the matK gene from the subtidal Zostera samples were identical to matK sequences obtained from Z. marina collected from intertidal habitats in Japan, Alaska, Oregon and California, but differed from Z. asiatica sequences accessioned into GenBank. This suggests the subtidal plants are conspecific with Z. marina, not Z. asiatica. However, we found that herbarium samples accessioned into the Kyoto University Herbarium, determined to be Z. asiatica, yielded 5.8S rDNA/ITS sequences consistent with either Z. japonica, in two cases, or Z. marina, in one case. Similar results were observed for the chloroplast matK gene; we found haplotypes that were inconsistent with published matK sequences from Z. asiatica collected from Japan. These results underscore the need for closer examination of the relationship between Z. marina along the Pacific Coast of North America, and Z. asiatica of Asia, for the retention and verification of specimens examined in scientific studies, and for assessment of the usefulness of morphological characters in the determination of taxonomic relationships within Zosteraceae. 相似文献
8.
Caio Vinicius Vivas Ramiris César Souza Moraes Anderson Alves-Araújo Marccus Alves Eduardo Mariano-Neto Cássio van den Berg Fernanda Amato Gaiotto 《Genetics and molecular biology》2014,37(4):662-670
The Atlantic Forest is a phytogeographic domain with a high rate of endemism and large species diversity. The Sapotaceae is a botanical family for which species identification in the Atlantic Forest is difficult. An approach that facilitates species identification in the Sapotaceae is urgently needed because this family includes threatened species and valuable timber species. In this context, DNA barcoding could provide an important tool for identifying species in the Atlantic Forest. In this work, we evaluated four plant barcode markers (matK, rbcL, trnH-psbA and the nuclear ribosomal internal transcribed spacer region - ITS) in 80 samples from 26 species of Sapotaceae that occur in the Atlantic Forest. ITS yielded the highest average interspecific distance (0.122), followed by trnH-psbA (0.019), matK (0.008) and rbcL (0.002). For species discrimination, ITS provided the best results, followed by matK, trnH-psbA and rbcL. Furthermore, the combined analysis of two, three or four markers did not result in higher rates of discrimination than obtained with ITS alone. These results indicate that the ITS region is the best option for molecular identification of Sapotaceae species from the Atlantic Forest. 相似文献
9.
Phylogeny of the Malus (Apple Tree) Species,Inferred from the Morphological Traits and Molecular DNA Analysis 总被引:4,自引:0,他引:4
Forte A. V. Ignatov A. N. Ponomarenko V. V. Dorokhov D. B. Savelyev N. I. 《Russian Journal of Genetics》2002,38(10):1150-1161
Some debated issues of the genus Malus (apple) taxonomy were examined using a variety of species from the collection of the Maikop Experimental Station, Vavilon Research Institute of Plant Industry (Krasnodar krai). Phylogenetic relationships among these species were studied using traditional analysis of morphological traits, RAPD, and complete sequencing of the 5"- internal transcribed spacer (ITS1), 5.8S rRNA, 3"- internal transcribed spacer (ITS2) (constituting a cluster of the rRNA genes), and the terminal fragment of the matK gene encoding chloroplast maturase. The results showed that the Sorbomalussection was polyphyletic; the American apple M. fusca was closely related to the species contributing to the East Asian center of the genus origin, and the American speciesM. angustifolia, M. coronaria, and M. ioensis were closely related to the M. trilobata relict species, whose assignment to the genus Malus is debated by some authors. Molecular analysis of the species relationships showed that the Middle Asian apple M. sieversii is the species from which apple domestication started. 相似文献
10.
Pablo Vargas Elena Carrió Beatriz Guzmán Elena Amat Jaime Güemes 《Journal of Biogeography》2009,36(7):1297-1312
Aim To infer phylogenetic relationships among Antirrhinum species and to reconstruct the historical distribution of observed sequence polymorphism through estimates of haplotype clades and lineage divergence. Location Antirrhinum is distributed primarily throughout the western Mediterranean, with 22 of 25 species in the Iberian Peninsula. Methods Plastid (83 trnS‐trnG and 83 trnK‐matK) and nuclear (87 ITS) sequences were obtained from 96 individuals representing 24 of the 25 Antirrhinum species. Sequences were analysed using maximum parsimony, Bayesian inference and statistical parsimony networking. Molecular clock estimates were obtained for plastid trnK‐matK sequences using the penalized likelihood approach. Results Phylogenetic results gave limited support for monophyletic groups within Antirrhinum. Fifty‐one plastid haplotypes were detected and 27 missing haplotypes inferred, which were all connected in a single, star‐like network. A significant number of species shared both the same haplotypes and the same geographical areas, primarily in eastern Iberia. Furthermore, many species harboured populations with unrelated haplotypes from divergent haplotype clades. Plastid haplotype distribution, together with nucleotide additivity in 59 of the 86 nuclear ribosomal ITS sequences, is interpreted as evidence of extensive hybridization. Lineage divergence estimates indicated that differentiation within Antirrhinum post‐dates the Miocene, when the Mediterranean climate was established. Main conclusions Incongruence between plastid sequences, nuclear sequences and taxonomic delimitation is interpreted as strong evidence of limited cladogenetic processes in Antirrhinum. Rather, extensive nucleotide additivities in ITS sequences in conjunction with haplotype and haplotype‐clade distributions related to geographical areas support both recent and ancient hybridization. This geographical pattern of Antirrhinum speciation, particularly in eastern Iberia, is congruent with isolation–contact–isolation processes in the Pleistocene. 相似文献
11.
Daniell H Lee SB Grevich J Saski C Quesada-Vargas T Guda C Tomkins J Jansen RK 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,112(8):1503-1518
Despite the agricultural importance of both potato and tomato, very little is known about their chloroplast genomes. Analysis of the complete sequences of tomato, potato, tobacco, and Atropa chloroplast genomes reveals significant insertions and deletions within certain coding regions or regulatory sequences (e.g., deletion of repeated sequences within 16S rRNA, ycf2 or ribosomal binding sites in ycf2). RNA, photosynthesis, and atp synthase genes are the least divergent and the most divergent genes are clpP, cemA, ccsA, and matK. Repeat analyses identified 33–45 direct and inverted repeats ≥30 bp with a sequence identity of at least 90%; all but five of the repeats shared by all four Solanaceae genomes are located in the same genes or intergenic regions, suggesting a functional role. A comprehensive genome-wide analysis of all coding sequences and intergenic spacer regions was done for the first time in chloroplast genomes. Only four spacer regions are fully conserved (100% sequence identity) among all genomes; deletions or insertions within some intergenic spacer regions result in less than 25% sequence identity, underscoring the importance of choosing appropriate intergenic spacers for plastid transformation and providing valuable new information for phylogenetic utility of the chloroplast intergenic spacer regions. Comparison of coding sequences with expressed sequence tags showed considerable amount of variation, resulting in amino acid changes; none of the C-to-U conversions observed in potato and tomato were conserved in tobacco and Atropa. It is possible that there has been a loss of conserved editing sites in potato and tomato.Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users. 相似文献
12.
Awad A. Algarni 《Saudi Journal of Biological Sciences》2022,29(2):1125-1133
The Kingdom of Saudi Arabia thrives with great plant diversity, including rare plants of the family Asphodelaceae that have multiple benefits and are still being studied. Aloe shadensis is one of these plants that must be preserved and documented in its natural environment. The most appropriate molecular approach currently approved for documentation is the sequencing of some genomic markers. The current study is the first to use genomic markers to record this rare plant. In this study, the plastid genes matK (Maturase K), rbcL (Ribulose-bisphosphate carboxylase/oxygenase large subunit), and the nuclear region ITS (Internal transcribed spacer) were used to reveal their efficiency in identifying the plant under study. This study is the first to deal with this plant and document it using these genetic markers. The study showed a promising result concerning identifying the sequence of the matK gene and ITS region, while the rbcL gene did not give a good indicator through the used primers. The obtained sequences of the matK gene and the ITS region were determined through two different sets of primers in each case then deposited in GenBank. The evolutionary relatedness of Aloe shadensis was established with the different species of Aloe. The study showed that the closest species is Aloe vera with a similarity of more than 99 %. The study concludes with the possibility of using these genes to correctly identify, distinguish and document the species of Aloe shadensis. 相似文献
13.
A 433-bp fragment of the mitochondrial cytochrome b gene and the entire nuclear ITS2 region were sequenced in an oak gall wasp species, Andricus curtisii, which represents 21 populations across its range in Turkey. Forty cytochrome b haplotypes and 63 ITS2 alleles were discovered among the 161 individuals studied. Remarkable genetic variation was detected in the species, with an average haplotype diversity (h) of 0.72 and 0.76 and an average nucleotide diversity (π) of 0.06 and 0.01 for the cyt b gene and the ITS region, respectively. Most populations were genetically distinct, possessing unique cytochrome b haplotypes. Maximum likelihood and Bayesian phylogenetic analyses and application of the haplotype network to both datasets revealed that the most basally located haplotypes/alleles were from the eastern part of Turkey. The detection of older sequences in the phylogenetic trees of the easterly located populations implied an eastern origin of the species. The application of a conventional insect mitochondrial DNA clock to the dataset suggested a splitting of ingroup haplotypes from the outgroup lineages predating the Pleistocene epoch and the formation of two major haplogroups that coincided with the oscillation of the early Pleistocene glaciations. 相似文献
14.
Sequence variation among 22 isolates representing a global distribution of the prymnesiophyte genus Phaeocystis has been compared using nuclear-encoded 18S rRNA genes and two non-coding regions: the ribosomal DNA internal transcribed spacer 1 (ITS1) separating the 18S rRNA and 5.8S rRNA genes and the plastid ribulose-1,5-bisphosphate carboxylase/oxygenase (RUBISCO) spacer flanked by short stretches of the adjacent large and small subunits (rbcL and rbcS). 18S rRNA can only resolve major species complexes. The analysis suggests that an undescribed unicellular Phaeocystis sp. (isolate PLY 559) is a sister taxon to the Mediterranean unicellular Phaeocystis jahnii; this clade branched prior to the divergence of all other Phaeocystis species, including the colonial ones. Little divergence was seen among the multiple isolates sequenced from each colonial species complex. RUBISCO spacer regions are even more highly conserved among closely related colonial Phaeocystis species and are identical in Phaeocystis antarctica, Phaeocystis pouchetii and two warm-temperate strains of Phaeocystis globosa, with a single base substitution in two cold-temperate strains of P. globosa. The RUBISCO spacer sequences from two predominantly unicellular Phaeocystis isolates from the Mediterranean Sea and PLY 559 were clearly different from other Phaeocystis strains. In contrast, ITS1 exhibited substantial inter- and intraspecific sequence divergence and showed more resolution among the taxa. Distinctly different copies of the ITS1 region were found in P. globosa, even among cloned DNA from a single strain, suggesting that it is a species complex and making this region unsuitable for phylogenetic analysis in this species. However, among nine P. antarctica strains, four ITS1 haplotypes could be separated. Using the branching order in the ITS1 tree we have attempted to trace the biogeographic history of the dispersal of strains in Antarctic coastal waters. 相似文献
15.
This study was aimed to authenticate and present phylogenetic relationship among 19 species of genus Chlorophytum using DNA barcoding. In all, 107 accessions were analyzed with eight plastid (matK, rbcL, trnH-psbA, rpoC1, ycf5, rpoB, atp and psbK-psbI) and six nuclear (ITS) markers. The matK and rbcL were found to be ideal markers for identification and discrimination of Chlorophytum species. Phylogenetic analysis based on matK and rbcL sequences resolved the species in two major clades. All markers, except matK and rbcL, showed ambiguous reads and paralogy in analysis. DGGE analysis showed the presence of pseudogenes and/or co-amplification in these markers, which caused poor sequence quality. Phylogeny and probable evolution of genus Chlorophytum was proposed on the basis of cytological, morphological and genetic information. 相似文献
16.
Odile Thiéry Mari Moora Martti Vasar Martin Zobel Maarja Öpik 《Symbiosis (Philadelphia, Pa.)》2012,58(1-3):135-147
Most molecular ecological studies of arbuscular mycorrhizal fungi (AMF) have been based on the rRNA gene sequences. However, information about intraspecific nucleotide variation is still limited in these fungi. In this study, we calculated the inter- and intrasporal nucleotide variation of Diversispora sp. EE1 using 78 cloned sequences from four spores within a ca 4960 bp fragment of the nuclear ribosomal operon spanning the near full length small ribosomal subunit (SSU) rRNA gene, the full internal transcribed spacer (ITS: ITS1-5.8S-ITS2) and ca 2740 bp of the large ribosomal subunit (LSU) rRNA gene. Data for each marker region (SSU, ITS and LSU) originated from the very same spores. Sequence variation resulting from point mutations and small indels was recorded in all regions. Highest sequence variation was observed in the ITS region at both the inter- and intrasporal levels. The ITS1 component was more variable than ITS2, whilst the 5.8S gene was the least variable component of the ITS region. Evolutionary divergence of gene copies between spores was intermediate for the LSU and lowest for the SSU. The SSU and the LSU genes had relatively similar evolutionary divergence per spore. Sequence variant richness was not exhaustive for any of the marker regions, indicating that multiple sequences per spore from multiple spores are needed when characterizing a species. This study provides reference sequences for ecological studies, permitting identification of AMF using any of the ribosomal regions or primer systems. 相似文献
17.
The genus Nuphar consists of yellow-flowered waterlilies and is widely distributed in north-temperate bodies of water. Despite regular taxonomic evaluation of these plants, no explicit phylogenetic hypotheses have been proposed for the genus. We investigated phylogenetic relationships in Nuphar using morphology and sequences of the chloroplast gene matK and of the internal transcribed spacer (ITS) regions of nuclear ribosomal DNA. Two major lineages within Nuphar are consistently resolved with the morphological and molecular data sets. One lineage comprises New World taxa and the other represents a primarily Old World lineage. Relationships within the major lineages were poorly resolved by morphology and ITS, yet certain relationships were elucidated by all analyses. Most notable is the strong support for a monophyletic lineage of dwarf taxa and the alliance of the North American N. microphylla with the Eurasian taxa. Minor discordance between the independent cladograms is accounted for by hybridization. The common taxonomic practice of uniting all North American and Eurasian taxa under one species is not supported phylogenetically. 相似文献
18.
Wilbert Serrano Rudolf Amann Ramon Rosselló-Mora Ulrich Fischer 《Systematic and applied microbiology》2010
Four species of marine purple sulfur bacteria of the genus Marichromatium have been validly described. A recent re-analysis of the 16S rRNA-based similarity and genomic DNA–DNA hybridizations (DDH) of the type strains [33] suggested that some of them are so closely related that they can be considered heterotypic synonyms. Here, we report on the evaluation of the multilocus sequence analysis approach (MLSA) for nine Marichromatium strains in order to resolve their intrageneric genealogical relationships. MLSA was based on six protein-coding genes (gyrB, recA, fusA, dnaK, pufM, and soxB), and the results were comparable to DDH. The phylogenetic tree constructed with the concatenated sequences, which also included the 16S rRNA gene and the internal transcriber spacer ITS region (4331 bp), separated the nine strains in four lineages that reflected the four Marichromatium species. The reconstructed phylogenetic tree based on concatenation of six protein-coding genes was also highly congruent with the tree topology based on the 16S rRNA gene. 相似文献
19.
Firouzeh Bordbar Mohammad Reza Rahiminejad Hojjatollah Saeidi Frank R. Blattner 《Plant Systematics and Evolution》2011,291(1-2):117-131
Cereal species of the grass tribe Triticeae are economically important and provide staple food for large parts of the human population. The Fertile Crescent of Southwest Asia harbors high genetic and morphological diversity of these species. In this study, we analyzed genetic diversity and phylogenetic relationships among D genome-bearing species of the wheat relatives of the genus Aegilops from Iran and adjacent areas using allelic diversity at 25 nuclear microsatellite loci, nuclear rDNA ITS, and chloroplast trnL-F sequences. Our analyses revealed high microsatellite diversity in Aegilops tauschii and the D genomes of Triticum aestivum and Ae. ventricosa, low genetic diversity in Ae. cylindrica, two different Ae. tauschii gene pools, and a close relationship among Ae. crassa, Ae. juvenalis, and Ae. vavilovii. In the latter species group, cloned sequences revealed high diversity at the ITS region, while in most other polyploids, homogenization of the ITS region towards one parental type seems to have taken place. The chloroplast genealogy of the trnL-F haplotypes showed close relationships within the D genome Aegilops species and T. aestivum, the presence of shared haplotypes in up to three species, and up to three different haplotypes within single species, and indicates chloroplast capture from an unidentified species in Ae. markgrafii. The ITS phylogeny revealed Triticum as monophyletic and Aegilops as monophyletic when Amblyopyrum muticum is included. 相似文献
20.
In Southern Italy, an endemic monotypic genus belonging to family Apiaceae occurs: Petagnaea (P. gussonei), relict of Tertiary flora, belonging to subfamily Saniculoideae. At present, P. gussonei is an endangered species and is included in various lists of species deserving special protection. The genus belongs to scapose hemicryptophytes and shares a sciaphilous habitat (hygrophilous woodland). This study is aimed at doing a complete contribution about the evolutionary history of Petagnaea, using molecular markers as plastidial DNA (cpDNA), nuclear ribosomal DNA (rDNA) and data present in literature. We used nucleotide sequences from four regions of the chloroplast genome (rps16 intron, trnL(UAA) intron, atpB-rbcL intergenic spacer, and partial matK gene) to investigate possible haplotypes in Petagnaea populations. To have an idea of the molecular relationships of all populations of P. gussonei, the internal transcribed spacer (ITS) sequences, already employed in recent studies, were obtained for 18 populations. These sequences in combination with other Saniculoideae ITS sequences available from GenBank have been used for a further phylogenetic analysis. The results agree with the current classification of Saniculoideae in placing P. gussonei in tribe Saniculeae, since P. gussonei is in basal position to Sanicula. According to intraspecific chloroplast DNA diversity, no different haplotypes were detected. In addition to molecular data, morphology, cytology, phytochemistry and conservation status have been considered in the discussion. 相似文献