cpDNA supports the identification of the major lineages of American <i>Blechnum</i> (Blechnaceae, Polypodiopsida) established by morphology

Blechnaceae is an important leptosporangiate family (9–10 genera, about 250 species). It is monophyletic and distributed mainly in tropical America and Australasia. Among the species 80% belong to Blechnum, a genus with a very complex taxonomy and uncertain internal relationships. In terms of American diversity, the results of morphological studies have arrived at 8 informal groups. Molecular works on this genus are scarce, and there is no information for the majority of American species. The main objective of this work was to evaluate whether the groups proposed to organise the diversity of American of Blechnum are consistent with a molecular analysis. We sequenced 2 chloroplastic regions from species representing all of the groups. In our molecular analysis most of the informal groups were maintained as well supported clades. Only 2 species, B. brasiliense and B. spicant, appear to be isolated from their alleged relatives. Combining our molecular results with previous morphological knowledge, we propose the recognition of 4 lineages: 1) B. serrulatum , 2) B. spicant, and 3) core Blechnum, which represents a large clade that can be divided into core Blechnum I (arborescent species, cordatoids, and B. brasiliense) and core Blechnum II (epiphytic species and herbaceous terrestrials, both monomorphic and dimorphic groups).Facultad de Ciencias Naturales y Muse

cpDNA supports the identification of the major lineages of American <i>Blechnum</i> (Blechnaceae, Polypodiopsida) established by morphology

Blechnaceae is an important leptosporangiate family (9–10 genera, about 250 species). It is monophyletic and distributed mainly in tropical America and Australasia. Among the species 80% belong to Blechnum, a genus with a very complex taxonomy and uncertain internal relationships. In terms of American diversity, the results of morphological studies have arrived at 8 informal groups. Molecular works on this genus are scarce, and there is no information for the majority of American species. The main objective of this work was to evaluate whether the groups proposed to organise the diversity of American of Blechnum are consistent with a molecular analysis. We sequenced 2 chloroplastic regions from species representing all of the groups. In our molecular analysis most of the informal groups were maintained as well supported clades. Only 2 species, B. brasiliense and B. spicant, appear to be isolated from their alleged relatives. Combining our molecular results with previous morphological knowledge, we propose the recognition of 4 lineages: 1) B. serrulatum , 2) B. spicant, and 3) core Blechnum, which represents a large clade that can be divided into core Blechnum I (arborescent species, cordatoids, and B. brasiliense) and core Blechnum II (epiphytic species and herbaceous terrestrials, both monomorphic and dimorphic groups).Laboratorio de Estudios de Anatomía Vegetal Evolutiva y Sistemátic

Bases de données génomiques et reconstructions phylogénétiques

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Le nodulome des lupins : Dynamique évolutive des gènes potentiellement impliqués dans la symbiose fixatrice d’azote dans un contexte de changement de spécificité hôte/symbiote

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Le nodulome des lupins : Dynamique évolutive des gènes potentiellement impliqués dans la symbiose fixatrice d’azote dans un contexte de changement de spécificité hôte/symbiote

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Bases de données génomiques et reconstructions phylogénétiques

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Le barcoding-ADN de la biodiversité

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Le nodulome des lupins : Dynamique évolutive des gènes potentiellement impliqués dans la symbiose fixatrice d’azote dans un contexte de changement de spécificité hôte/symbiote

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Tracking the evolutionary history of the Allium ampeloprasum L. complex (section Allium) provides evidence of the contribution of North African diploids to the formation of allopolyploid horticultural groups

International audienceThe economically important Allium ampeloprasum L. represents a polyploid complex, comprising hexa- and octoploid Great Headed Garlic horticultural cultivars (6x-8x GHG) and several traditional varieties of the tetraploid (4x) leeks (Leek, Bulbous leek, Kurrat and Pearl onion). Its wild representatives were indicated as rare in the Mediterranean region. This study aims to explore the diversity and origin of polyploidy in this complex, including its wild relatives A. baeticum Bossier and A. guttatum Steven with particular focus on the poorly investigated North-African region. Natural populations were sampled in Algeria in various bioclimatic conditions, then subjected to karyological and molecular phylogenetic analyses based on nuclear rDNA ITS region and chloroplast trnL-trnF and trnD-trnT intergenic spacers. Comparative analyses included available Genbank accession sequences representing old-world relatives. Chromosome count surveys revealed an unexpected higher occurrence of diploid (2n = 16) than tetraploid (2n = 32) cytotypes. The phylogenetic analyses first allowed positioning the Algerian material within the A. ampeloprasum complex. Interestingly, all the Algerian diploid and tetraploid populations from A. ampeloprasum and A. baeticum form a distinct monophyletic group. The results provide novel and robust evidence demonstrating that the North African diploid A. ampeloprasum genetic pool widely contributed as a source of progenitors not only for the A. ampeloprasum and A. baeticum Algerian tetraploids, but also in the formation of the GHG and Leek cultivated allopolyploids. Therefore, the North African populations emerge as an important reservoir of new wild genetic resources of great interest for tracing the origin of crop domestication and for breeding programs of cultivated varieties

Screening diversity and distribution of Copia retrotransposons reveals a specific amplification of BARE1 elements in genomes of the polyploid Hordeum murinum complex

International audienceWe explored diversity, distribution and evolutionary dynamics of Ty1-Copia retrotransposons in the genomes of the Hordeum murinum polyploid complex and related taxa. Phylogenetic and fluorescent in situ hybridization (FISH) analyses of reverse transcriptase sequences identified four Copia families in these genomes the predominant BARE1 (including three groups or subfamilies, A, B and C), and the less represented RIRE1, IKYA and TAR-1. Within the BARE1 family, BARE1-A elements and a subgroup of BARE1-B elements (named B1) have proliferated in the allopolyploid members of the H. murinum complex (H. murinum and H. leporinum), and in their extant diploid progenitor, subsp. glaucum. Moreover, we found a specific amplification of BARE1-B elements within each Hordeum species surveyed. The low occurrence of RIRE1, IKYA and TAR-1 elements in the allopolyploid cytotypes suggests that they are either weakly represented or highly degenerated in their diploid progenitors. The results demonstrate that BARE1-A and BARE1-B1 Copia elements are particularly well represented in the genomes of the H. murinum complex and constitute its genomic hallmark. No BARE1-A and -B1 homologs were detected in the reference barley genome. The similar distribution of RT-Copia probes across chromosomes of diploid, tetraploid and hexaploid taxa of the murinum complex shows no evidence of proliferation following polyploidization