Chemotaxonomy of the genus Carex (Cyperaceae)

1990 ◽  
Vol 68 (7) ◽  
pp. 1457-1461 ◽  
Author(s):  
James R. Manhart
Keyword(s):  
Chloroplast Dna ◽  
Phylogenetic Trees ◽  
Dna Analysis ◽  
Morphological Variability ◽  
Hybrid Origin ◽  
Enzyme Electrophoresis ◽  
Sequence Comparisons ◽  
Phenotypic Characters ◽  
Plant Groups ◽  
Chloroplast Dnas

The major categories of chemosystematic comparisons that were used successfully or are of potential use in Carex include flavonoid analysis, enzyme electrophoresis, and chloroplast DNA mapping and sequencing. The flavonoid work consists mostly of broad scale comparisons of aglycone distributions in a number of sedge genera to include some members of Carex. These comparisons proved to be of limited use in understanding phylogenetic relationships within the genus Carex. However, detailed flavonoid analyses of sections Laxiflorae and Acrocystis demonstrated the utility of flavonoid surveys in Carex at infrasectional levels and possibly at intersectional levels. Enzyme electrophoretic data were used to determine whether the morphological variability present in a species complex is the result of hybridization, phenotypic plasticity, or recent divergence. The C. crinita complex is an example in which intermediate forms are probably not the result of hybridization. Conversely, allozyme data for section Sylvaticae indicate that some of the taxa in this section are of hybrid origin. One of the most promising developments in systematic studies was the use of chloroplast DNA analysis. It was demonstrated in a number of plant groups that restriction endonuclease and sequence comparisons of chloroplast DNAs can be used to construct phylogenetic trees that have homoplasy levels much lower than those constructed from phenotypic characters.

scholarly journals Molecular Phylogenetic Diversity and Biological Characterization of Diaporthe Species Associated with Leaf Spots of Camellia sinensis in Taiwan

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1434
Author(s):  
Hiran A. Ariyawansa ◽  
Ichen Tsai ◽  
Jian-Yuan Wang ◽  
Patchareeya Withee ◽  
Medsaii Tanjira ◽  
...  
Keyword(s):  
Camellia Sinensis ◽  
Leaf Spot ◽  
Phylogenetic Trees ◽  
Fungal Infections ◽  
Elongation Factor ◽  
Fungal Species ◽  
Tea Leaves ◽  
Phenotypic Characters ◽  
Leaf Spots ◽  
Molecular Phylogenetic

Camellia sinensis is one of the major crops grown in Taiwan and has been widely cultivated around the island. Tea leaves are prone to various fungal infections, and leaf spot is considered one of the major diseases in Taiwan tea fields. As part of a survey on fungal species causing leaf spots on tea leaves in Taiwan, 19 fungal strains morphologically similar to the genus Diaporthe were collected. ITS (internal transcribed spacer), tef1-α (translation elongation factor 1-α), tub2 (beta-tubulin), and cal (calmodulin) gene regions were used to construct phylogenetic trees and determine the evolutionary relationships among the collected strains. In total, six Diaporthe species, including one new species, Diaporthe hsinchuensis, were identified as linked with leaf spot of C. sinensis in Taiwan based on both phenotypic characters and phylogeny. These species were further characterized in terms of their pathogenicity, temperature, and pH requirements under laboratory conditions. Diaporthe tulliensis, D. passiflorae, and D. perseae were isolated from C. sinensis for the first time. Furthermore, pathogenicity tests revealed that, with wound inoculation, only D. hongkongensis was pathogenic on tea leaves. This investigation delivers the first assessment of Diaporthe taxa related to leaf spots on tea in Taiwan.

scholarly journals Discordant evolution of organellar genomes in peas (Pisum L.)

2020 ◽  
Author(s):  
Vera S. Bogdanova ◽  
Natalia V. Shatskaya ◽  
Anatoliy V. Mglinets ◽  
Oleg E. Kosterin ◽  
Gennadiy V. Vasiliev
Keyword(s):  
Phylogenetic Trees ◽  
Nuclear Genome ◽  
Nuclear Gene ◽  
Plant Evolution ◽  
Hybrid Origin ◽  
Mitochondrial Genomes ◽  
North East ◽  
Plastid Genomes ◽  
First Time ◽  
Evolutionary Fate

AbstractPlastids and mitochondria have their own small genomes which do not undergo meiotic recombination and may have evolutionary fate different from each other and nuclear genome, thus highlighting interesting phenomena in plant evolution. We for the first time sequenced mitochondrial genomes of pea (Pisum L.), in 38 accessions mostly representing diverse wild germplasm from all over pea geographical range. Six structural types of pea mitochondrial genome were revealed. From the same accessions, plastid genomes were sequenced. Bayesian phylogenetic trees based on the plastid and mitochondrial genomes were compared. The topologies of these trees were highly discordant implying not less than six events of hybridisation of diverged wild peas in the past, with plastids and mitochondria differently inherited by the descendants. Such discordant inheritance of organelles is supposed to have been driven by plastid-nuclear incompatibility, known to be widespread in pea wide crosses and apparently shaping the organellar phylogenies. The topology of a phylogenetic tree based on the nucleotide sequence of a nuclear gene His5 coding for a histone H1 subtype corresponds to the current taxonomy and resembles that based on the plastid genome. Wild peas (Pisum sativum subsp. elatius s.l.) inhabiting Southern Europe were shown to be of hybrid origin resulting from crosses of peas similar to those presently inhabiting south-east and north-east Mediterranean in broad sense.

scholarly journals Population genetic structure of pedunculate oak (Quercus robur L.) in Belarus according to the analysis of chloroplast DNA

2021 ◽  
pp. 59-70
Author(s):  
Vladimir E. Padutov
Keyword(s):  
Genetic Structure ◽  
Chloroplast Dna ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Quercus Robur ◽  
Phylogenetic Trees ◽  
Rflp Analysis ◽  
Pedunculate Oak ◽  
Maximum Likelihood Methods ◽  
The Republic

Pedunculate oak (Quercus robur L.) is one of the main forest forming species in the Republic of Belarus. Its population genetic structure was formed under the influence of various migration processes. Six chloroplast DNA loci (µdt1, µdt3, µdt4, µcd4, µcd5 and µkk4) were used for the genogeographic study. The material for the analysis was collected in 100 oak forest stands (2325 samples); 18 allelic variants were identified, which are grouped into 17 different combinations (haplotypes). Five of them are widespread (the proportion of occurrence varies from 7 to 48 %, totalling 85 %). The remaining 12 are rare (the proportion of occurrence varies from 1 to 3 %, totalling 15 %). Phylogenetic trees constructed using the nearest neighbour and maximum likelihood methods show the presence of two groups (branches) of haplotypes. One of it comprises 8 variants including 2 dominant haplotypes and the other comprises 9 variants including 3 dominant haplotypes. PCR-RFLP analysis of chloroplast DNA showed that the pedunculate oak in Belarus originates from the Balkan refugium. Haplotype No. 1 (µdt189, µdt3123, µdt4142, µcd494, µcd574, µkk4109) is found almost everywhere in Belarus with the exception of the southwest and northeast, while haplotype No. 8 (µdt189, µdt3121, µdt4142, µcd494, µcd574, µkk4109) is mainly localised in the southwest and northeast. Haplotypes No. 3 (µdt189, µdt3120, µdt4141, µcd494, µcd575, µkk4109) and No. 7 (µdt189, µdt3122, µdt4142, µcd494, µcd574, µkk4109) predominantly found in the west of the country. Haplotype No. 2 (µdt190, µdt3120, µdt4141, µcd495, µcd574, µkk4109) is typical for the southeast.

scholarly journals Molecular analysis of the hot spot region related to length mutations in wheat chloroplast DNAs. I. Nucleotide divergence of genes and intergenic spacer regions located in the hot spot region.

Genetics ◽  
1991 ◽  
Vol 129 (3) ◽  
pp. 873-884 ◽  
Author(s):  
Y Ogihara ◽  
T Terachi ◽  
T Sasakuma
Keyword(s):  
Dna Sequences ◽  
Gene Evolution ◽  
Hot Spot ◽  
Intergenic Spacer ◽  
Open Reading Frames ◽  
Coding Region ◽  
Nucleotide Substitutions ◽  
Plant Groups ◽  
Nucleotide Divergence ◽  
Chloroplast Dnas

Abstract The nucleotide divergence of chloroplast DNAs around the hot spot region related to length mutation in Triticum (wheat) and Aegilops was analyzed. DNA sequences (ca. 4.5 kbp) of three chloroplast genome types of wheat complex were compared with one another and with the corresponding region of other grasses. The sequences region contained rbcL and psaI, two open reading frames, and a pseudogene, rpl23' (pseudogene for ribosomal protein L23) disrupted by AT-rich intergic spacer regions. The evolution of these genes in the closely related wheat complex is characterized by nonbiased nucleotide substitutions in terms of being synonymous/nonsynonymous, having A-T pressure transitions over transversions, and frequent changes at the third codon position, in contrast with the gene evolution among more distant plant groups where biased nucleotide substitutions have frequently occurred. The sequences of these genes had diverged almost in proportion to taxonomic distance. The sequence of the pseudogene rpl23' changed approximately two times faster than that of the coding region. Sequence comparison between the pseudogene and its protein-coding counterpart revealed different degrees of nucleotide homology in wheat, rice and maize, suggesting that the transposition timing of the pseudogene differed and/or that different rates of gene conversion operated on the pseudogene in the cpDNA of the three plant groups in Gramineae. The intergenic spacer regions diverged approximately ten times faster than the genes. The divergence of wheat from barley, and that from rice are estimated based on the nucleotide similarity to be 1.5, 10 and 40 million years, respectively.

scholarly journals Reciprocal hybridization between diploid Ficaria calthifolia and tetraploid Ficaria verna subsp. verna: evidence from experimental crossing, genome size and molecular markers

2019 ◽  
Vol 189 (3) ◽  
pp. 293-310 ◽  
Author(s):  
Ondřej Popelka ◽  
Michal Sochor ◽  
Martin Duchoslav
Keyword(s):  
Genome Size ◽  
Morphological Variability ◽  
Plastid Dna ◽  
Genotypic Diversity ◽  
Hybrid Origin ◽  
Aflp Analysis ◽  
Sympatric Populations ◽  
Aflp Data ◽  
Evolutionary Forces ◽  
Genetic Clusters

Abstract Ficaria is a taxonomically intriguing polyploid complex with high morphological variability. Both hybridization and polyploidization have been suggested as the main evolutionary forces behind the high morphological variability in this genus; however, detailed studies are lacking. In Central Europe, two Ficaria taxa (diploid F. calthifolia and tetraploid F. verna subsp. verna) occasionally co-occur in local sympatry, which might result in hybridization. We investigated sympatric populations of the two Ficaria taxa using flow cytometry, chromosome counts, AFLP analysis and plastid DNA sequencing; we also performed experimental homoploid and heteroploid crosses to determine the frequency and direction of hybrid triploid formation, an alternative route of triploid origin (autopolyploidy) and the possibility of a one-step neoallotetraploid origin. Sympatric populations were composed of three genetic clusters corresponding to diploid F. calthifolia (2n = 16), tetraploid F. verna subsp. verna (2n = 32) and triploid plants (2n = 24). The holoploid genome size and AFLP data suggest a hybrid origin of the triploids, thereby making their formation via autopolyploidization in F. calthifolia unlikely. The triploid populations are monoclonal and of independent origin. In contrast, the parental populations exhibit high genotypic diversity and frequent sexual reproduction, including those of predominantly asexual F. verna subsp. verna. Experimental crossing confirmed that both parental taxa produce fertile seeds via a sexual pathway, but not by apomixis, and that both serve as pollen acceptors in heteroploid crosses, which is consistent with the plastid sequencing. However, hybridization is asymmetric, with maternal-excess crosses being significantly more successful. No signs of neoautotetraploidization or neoallotetraploidization were detected. In summary, recent gene flow between the studied Ficaria taxa is either limited or absent.

The Drosophila montium subgroup species. Phylogenetic relationships based on mitochondrial DNA analysis

Genome ◽  
1996 ◽  
Vol 39 (5) ◽  
pp. 874-883 ◽  
Author(s):  
Nikolas Nikolaidis ◽  
Zacharias G. Scouras
Keyword(s):  
Mitochondrial Dna ◽  
Phylogenetic Relationships ◽  
Phylogenetic Trees ◽  
Dna Analysis ◽  
Restriction Site ◽  
Species Group ◽  
The Other ◽  
Complex Species ◽  
Restriction Site Maps ◽  
Montium Subgroup

Mitochondrial DNA (mtDNA) restriction site maps for three Drosophila montium subgroup species of the melanogaster species group, inhabiting Indian and Afrotropical montium subgroup territories, were established. Taking into account previous mtDNA data concerning six oriental montium species, a phylogeny was established using distance-matrix and parsimony methods. Both genetic diversity and mtDNA size variations were found to be very narrow, suggesting close phylogenetic relationships among all montium species studied. The phylogenetic trees that were constructed revealed three main lineages for the montium subgroup species studied: one consisting of the Afrotropical species Drosophila seguyi, which is placed distantly from the other species, one comprising the north-oriental (Palearctic) species, and one comprising the southwestern (south-oriental, Australasian, Indian, and Afrotropical) species. The combination of the mtDNA data presented here with data from other species belonging to the melanogaster and obscura subgroups revealed two major clusters: melanogaster and obscura. The melanogaster cluster is further divided into two compact lineages, comprising the montium subgroup species and the melanogaster complex species; the species of the other complex of the melanogaster subgroup, yakuba, disperse among the obscura species. The above grouping is in agreement with the mtDNA size variations of the species. Overall, among all subgroups studied, the species of the montium subgroup seem to be the most closely related. Key words : mtDNA restriction site maps, mtDNA size variations, Drosophila, phylogeny.

CHLOROPLAST DNA VARIATION AND EVOLUTION IN PISUM: PATTERNS OF CHANGE AND PHYLOGENETIC ANALYSIS

Genetics ◽  
1985 ◽  
Vol 109 (1) ◽  
pp. 195-213
Author(s):  
Jeffrey D Palmer ◽  
Richard A Jorgensen ◽  
William F Thompson
Keyword(s):  
Chloroplast Dna ◽  
Chloroplast Genome ◽  
Restriction Site ◽  
Garden Pea ◽  
Dna Variation ◽  
Mitochondrial Dnas ◽  
Chloroplast Dna Variation ◽  
Dna Restriction ◽  
Chloroplast Dnas ◽  
High Degree

ABSTRACT Variation in 30 chloroplast DNAs, representing 22 wild and cultivated accessions in the genus Pisum, was analyzed by comparing fragment patterns produced by 16 restriction endonucleases. Three types of mutations were detected. First, an inversion of between 2.2 kilobase pairs (kb) and 5.2 kb distinguished a population of P. humile from all other Pisum accessions examined. Second, deletions and insertions of between 50 and 1200 base pairs produced small restriction fragment length variations in four regions of the 120-kb chloroplast genome. Two of these regions—one of which is located within the sequence that is inverted in P. humile—showed a high degree of size polymorphism, to the extent that size differences were detected between individuals from the same accession. Finally, a total of only 11 restriction site mutations were detected among the 165 restriction sites sampled in the 30 DNAs. Based on these results and previous data, we conclude that the chloroplast genome is evolving very slowly relative to nuclear and mitochondrial DNAs. The Pisum chloroplast DNA restriction site mutations define two major lineages: One includes all tested accessions of P. fulvum, which is known to be cytogenetically quite distinct from all other Pisum taxa. The second includes 12 of 13 cultivated lines of the garden pea (P. sativum) and a wild population of P. humile from northern Israel. These observations strongly reinforce an earlier conclusion that the cultivated pea was domesticated primarily from northern populations of P. humile. A 13th P. sativum cultivar has a chloroplast genome that is significantly different from those of the aforementioned lines and somewhat more similar to those of P. elatius and southern populations of P. humile. This observation indicates that secondary hybridization may have occurred during the domestication of the garden pea.

scholarly journals An alignment-free heuristic for fast sequence comparisons with applications to phylogeny reconstruction

2020 ◽  
Vol 21 (S6) ◽  
Author(s):  
Sriram P. Chockalingam ◽  
Jodh Pannu ◽  
Sahar Hooshmand ◽  
Sharma V. Thankachan ◽  
Srinivas Aluru
Keyword(s):  
Phylogenetic Trees ◽  
Linear Time ◽  
Sequence Similarity ◽  
Similarity Measures ◽  
Phylogeny Reconstruction ◽  
Greedy Heuristics ◽  
Biological Sequences ◽  
Sequence Comparisons ◽  
Multiple Sequence ◽  
Alignment Free

Abstract Background Alignment-free methods for sequence comparisons have become popular in many bioinformatics applications, specifically in the estimation of sequence similarity measures to construct phylogenetic trees. Recently, the average common substring measure, ACS, and its k-mismatch counterpart, ACSk, have been shown to produce results as effective as multiple-sequence alignment based methods for reconstruction of phylogeny trees. Since computing ACSk takes O(n logkn) time and hence impractical for large datasets, multiple heuristics that can approximate ACSk have been introduced. Results In this paper, we present a novel linear-time heuristic to approximate ACSk, which is faster than computing the exact ACSk while being closer to the exact ACSk values compared to previously published linear-time greedy heuristics. Using four real datasets, containing both DNA and protein sequences, we evaluate our algorithm in terms of accuracy, runtime and demonstrate its applicability for phylogeny reconstruction. Our algorithm provides better accuracy than previously published heuristic methods, while being comparable in its applications to phylogeny reconstruction. Conclusions Our method produces a better approximation for ACSk and is applicable for the alignment-free comparison of biological sequences at highly competitive speed. The algorithm is implemented in Rust programming language and the source code is available at https://github.com/srirampc/adyar-rs.

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