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Robert P. Adams - One of the best experts on this subject based on the ideXlab platform.
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Gene flow between diploid and tetraploid junipers - two contrasting evolutionary pathways in two Juniperus populations
BMC Evolutionary Biology, 2020Co-Authors: Perla Farhat, Sonja Siljak-yakovlev, Nicolas Valentin, Carlos Fabregat, Silvia Lopez-udias, Carlos Salazar-mendias, Joaquín Altarejos, Robert P. AdamsAbstract:Background Gene flow and polyploidy have been found to be important in Juniperus evolution. However, little evidence has been published elucidating the association of both phenomena in juniper taxa in the wild. Two main areas were studied in Spain (Eastern Iberian Range and Sierra de Baza) with both diploid and tetraploid taxa present in sympatry. Gene flow and ploidy level were assessed for these taxa and the resulted offspring. Results Twenty-two allo-triploid hybrids between J. sabina var. sabina and J. thurifera were found in the Eastern Iberian Range population. However, in the Sierra de Baza population no triploids were found. Instead, 18 allo-tetraploid hybrids between two tetraploid taxa: J. sabina var. balkanensis and J. thurifera were discovered. High genetic diversity was exhibited among the tetraploid hybrids at Sierra de Baza, in contrast to the genetically identical triploid hybrids at the Eastern Iberian Range; this suggests meiotic difficulties within the triploid hybrids. In addition, unidirectional gene flow was observed in both studied areas. Conclusion Polyploidy and hybridization can be complementary partners in the evolution of Juniperus taxa in sympatric occurrences. Juniperus was shown to be an ideal coniferous model to study these two phenomena, independently or in concert.
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phylogenomic evidence for ancient recombination between plastid genomes of the cupressus Juniperus xanthocyparis complex cupressaceae
BMC Evolutionary Biology, 2018Co-Authors: Robert P. Adams, Andan Zhu, Weishu Fan, Jeffrey P MowerAbstract:Phylogenetic relationships among Eastern Hemisphere cypresses, Western Hemisphere cypresses, junipers, and their closest relatives are controversial, and generic delimitations have been in flux for the past decade. To address relationships and attempt to produce a more robust classification, we sequenced 11 new plastid genomes (plastomes) from the five variously described genera in this complex (Callitropsis, Cupressus, Hesperocyparis, Juniperus, and Xanthocyparis) and compared them with additional plastomes from diverse members of Cupressaceae. Phylogenetic analysis of protein-coding genes recovered a topology in which Juniperus is sister to Cupressus, whereas a tree based on whole plastomes indicated that the Callitropsis-Hesperocyparis-Xanthocyparis (CaHX) clade is sister to Cupressus. A sliding window analysis of site-specific phylogenetic support identified a ~ 15 kb region, spanning the genes ycf1 and ycf2, which harbored an anomalous signal relative to the rest of the genome. After excluding these genes, trees based on the remainder of the genes and genome consistently recovered a topology grouping the CaHX clade and Cupressus with strong bootstrap support. In contrast, trees based on the ycf1 and ycf2 region strongly supported a sister relationship between Cupressus and Juniperus. These results demonstrate that standard phylogenomic analyses can result in strongly supported but conflicting trees. We suggest that the conflicting plastomic signals result from an ancient introgression event involving ycf1 and ycf2 that occurred in an ancestor of this species complex. The introgression event was facilitated by plastomic recombination in an ancestral heteroplasmic individual carrying distinct plastid haplotypes, offering further evidence that recombination occurs between plastomes. Finally, we provide strong support for previous proposals to recognize five genera in this species complex: Callitropsis, Cupressus, Hesperocyparis, Juniperus, and Xanthocyparis.
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predominant and substoichiometric isomers of the plastid genome coexist within Juniperus plants and have shifted multiple times during cupressophyte evolution
Genome Biology and Evolution, 2014Co-Authors: Wenhu Guo, Robert P. Adams, Weishu Fan, Andrea E Schwarzbach, Felix Grewe, Amie Coboclark, Zelin Duan, Jeffrey P MowerAbstract:Most land plant plastomes contain two copies of a large inverted repeat (IR) that promote high-frequency homologous recombination to generate isomeric genomic forms. Among conifer plastomes, this canonical IR is highly reduced in Pinaceae and completely lost from cupressophytes. However, both lineages have acquired short, novel IRs, some of which also exhibit recombinational activity to generate genomic structural diversity. This diversity has been shown to exist between, and occasionally within, cupressophyte species, but it is not known whether multiple genomic forms coexist within individual plants. To examine the recombinational potential of the novel cupressophyte IRs within individuals and between species, we sequenced the plastomes of four closely related species of Juniperus. The four plastomes have identical gene content and genome organization except for a large 36 kb inversion between approximately 250 bp IR containing trnQ-UUG. Southern blotting showed that different isomeric versions of the plastome predominate among individual junipers, whereas polymerase chain reaction and high-throughput read-pair mapping revealed the substoichiometric presence of the alternative isomeric form within each individual plant. Furthermore, our comparative genomic studies demonstrate that the predominant and substoichiometric arrangements of this IR have changed several times in other cupressophytes as well. These results provide compelling evidence for substoichiometric shifting of plastomic forms during cupressophyte evolution and suggest that substoichiometric shifting activity in plastid genomes may be adaptive.
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phylogeny of Juniperus using nrdna and four cpdna regions
Phytologia., 2013Co-Authors: Robert P. Adams, Andrea E SchwarzbachAbstract:The Phylogeny of Juniperus is presented based on nrDNA (ITS), petN-psbM, trnS-trnG, trnD-trnT, trnL-trnF sequencing (4411 bp) utilizing all currently recognized species. The major clades of the phylogenetic tree were congruent with the previously published phylogenetic tree of Mao et al. (2010) that had a subset of taxa of the current study. The lone species with serrate leaves in the eastern hemisphere, J. phoenicea, was found to be in a clade quite separated from the serrate junipers of North America. Juniperus phoenicea is referred to as 'pseudoserrate' to distinguish it from the semi-arid, serrate leaf junipers of the western hemisphere. Section Sabina is the most derived group and has radiated into niches in both the eastern and western hemispheres with approx. 60 species. Published on-line: www.phytologia.org Phytologia 95(2): 179-187 (May 1, 2013).
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taxonomy of the multi seeded entire leaf taxa of Juniperus section sabina sequence analysis of nrdna and four cpdna regions
Phytologia, 2012Co-Authors: Robert P. Adams, Andrea E SchwarzbachAbstract:An analysis of the multi-seeded, entire leaf margined taxa of Juniperus sect. Sabina is presented based on nrDNA and four cpDNA regions. These DNA data revealed several previously unknown affinities with J. sabina and J. chinensis, better resolution of the J. excelsa - polycarpos complex and the Caribbean junipers, including the recognition of Juniperus gracilior var. saxicola, comb. nov. and Juniperus semiglobosa var. jarkendensis, comb. nov. Juniperus sabina var. davurica (Mongolia) was found to be clearly separated from J. sabina (Europe), supporting the recognition of J. davurica Pall., J. d. var. arenaria, comb. nov. and J. d. var. mongolensis, comb. nov. The taxonomy of the entire group is reviewed and necessary changes made in several taxa. Phytologia 94(3): 350-366 (December 1, 2012).
Campo Moreno Sergio - One of the best experts on this subject based on the ideXlab platform.
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Cartografía de los sabinares de Juniperus turbinata Guss. en la reserva de la biosfera de El Hierro (Islas Canarias) mediante teledetección
'Edicions de la Universitat de Barcelona', 2021Co-Authors: Campo Moreno SergioAbstract:Los sabinares de Juniperus turbinata Guss. más extensos del archipiélago Canario se encuentran en El Hierro, la isla más sudoccidental. La orografía de la isla es abrupta siendo la cima más alta Malpaso con 1.501 m. Los vientos alisios tienen una influencia desde la vertiente septentrional hasta la meridional. La combinación de los vientos alisios del NE y la topografía de la isla producen nubosidad en cotas medias y altas la mayoría de los días del año. El género Juniperus es un taxón protegido en la legislación europea, en la española y en diversas comunidades autonómicas entre las que se encuentra Canarias. Los avances en teledetección permiten disponer de imágenes de gran resolución, haciendo posible delimitar con más precisión la superficie de los sabinares, aumentando la fiabilidad de aquellas zonas poco accesibles, además son una alternativa ante la dificultad del trabajo de campo. Se han realizado estudios sobre la biodiversidad de los sabinares de la isla de El Hierro, el estado actual de sus poblaciones, su capacidad de regeneración, su posible regresión y las actuaciones a seguir para favorecer su conservación. El objetivo principal de este trabajo fue la elaboración de la cartografía del Juniperus turbinata Guss. en la isla de El Hierro, a partir de imágenes del GeoEye-1 y determinar la superficie y la densidad de individuos. Como la obtención de imágenes de satélite produce distorsiones geométricas, están afectadas por la atmósfera y por el relieve, se realizaron las correcciones geométrica y radiométrica, que debido a las características de la isla han sido bastante laboriosas. Se calcularon diferentes índices de vegetación y se presentan los resultados obtenidos de corrección y clasificación de las coberturas vegetales existentes. Por fuentes históricas se sabe que su extensión había sido mayor, pero debido a factores antrópicos y ambientales se ha reducido considerablemente su superficie. Los resultados de esta investigación permitieron conocer la extensión actual y densidad de la sabina en función del tipo de sabinar, siendo una información fundamental para la gestión de la reserva.The Juniperus turbinata Guss junipers, most extensive of the Canarian archipelago, are located in the El Hierro, it is the most sub-western island. The orography of the island is abrupt, with the highest summit being Malpaso with 1,501 m. The trade winds have an influence from the northern slope to the southern one. The combination of the trade winds of the NE and the topography of the island produces cloudiness in medium and high levels most days of the year. The genus Juniperus is a protected taxon in European legislation, in the Spanish and in various autonomous communities (Canary Islands and Andalusia). The advances in remote sensing allow to have images of great resolution, making it possible to delimit with more precision the surface of the junipers, increasing the reliability of those inaccessible areas. In addition they are an alternative before the difficulty of the field work. Studies have been carried out on the biodiversity of the junipers on the island of El Hierro, the current state of their populations, their capacity for regeneration, their possible regression and the actions to be taken to promote their conservation. The main objective of this work was the elaboration of the cartography of the Juniperus turbinata Guss., in the island of El Hierro, from GeoEye-1 images, and to determine the surface and density of individuals. As the obtaining of satellite images produces geometric distortions, they are affected by the atmosphere and by the relief, for that reason the geometric and radiometric corrections were made, which due to the characteristics of the island have been quite laborious. Different vegetation indexes were calculated and the results obtained the correction and classification of the existing vegetation covers are presented. Through historical sources it is known that its extension had been greater, but due to anthropic and environmental factors its surface has been considerably reduced. The results of this investigation allowed to know the current extension and density of the juniper according to the type of juniper, being a fundamental information for the management of the reserve
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Cartografía de los sabinares de Juniperus turbinata Guss. en la reserva de la biosfera de El Hierro (Islas Canarias) mediante teledetección
'Edicions de la Universitat de Barcelona', 2021Co-Authors: Campo Moreno SergioAbstract:[spa] Los sabinares de Juniperus turbinata Guss. más extensos del archipiélago Canario se encuentran en El Hierro, la isla más sudoccidental. La orografía de la isla es abrupta siendo la cima más alta Malpaso con 1.501 m. Los vientos alisios tienen una influencia desde la vertiente septentrional hasta la meridional. La combinación de los vientos alisios del NE y la topografía de la isla producen nubosidad en cotas medias y altas la mayoría de los días del año. El género Juniperus es un taxón protegido en la legislación europea, en la española y en diversas comunidades autonómicas entre las que se encuentra Canarias. Los avances en teledetección permiten disponer de imágenes de gran resolución, haciendo posible delimitar con más precisión la superficie de los sabinares, aumentando la fiabilidad de aquellas zonas poco accesibles, además son una alternativa ante la dificultad del trabajo de campo. Se han realizado estudios sobre la biodiversidad de los sabinares de la isla de El Hierro, el estado actual de sus poblaciones, su capacidad de regeneración, su posible regresión y las actuaciones a seguir para favorecer su conservación. El objetivo principal de este trabajo fue la elaboración de la cartografía del Juniperus turbinata Guss. en la isla de El Hierro, a partir de imágenes del GeoEye-1 y determinar la superficie y la densidad de individuos. Como la obtención de imágenes de satélite produce distorsiones geométricas, están afectadas por la atmósfera y por el relieve, se realizaron las correcciones geométrica y radiométrica, que debido a las características de la isla han sido bastante laboriosas. Se calcularon diferentes índices de vegetación y se presentan los resultados obtenidos de corrección y clasificación de las coberturas vegetales existentes. Por fuentes históricas se sabe que su extensión había sido mayor, pero debido a factores antrópicos y ambientales se ha reducido considerablemente su superficie. Los resultados de esta investigación permitieron conocer la extensión actual y densidad de la sabina en función del tipo de sabinar, siendo una información fundamental para la gestión de la reserva.[eng] The Juniperus turbinata Guss junipers, most extensive of the Canarian archipelago, are located in the El Hierro, it is the most sub-western island. The orography of the island is abrupt, with the highest summit being Malpaso with 1,501 m. The trade winds have an influence from the northern slope to the southern one. The combination of the trade winds of the NE and the topography of the island produces cloudiness in medium and high levels most days of the year. The genus Juniperus is a protected taxon in European legislation, in the Spanish and in various autonomous communities (Canary Islands and Andalusia). The advances in remote sensing allow to have images of great resolution, making it possible to delimit with more precision the surface of the junipers, increasing the reliability of those inaccessible areas. In addition they are an alternative before the difficulty of the field work. Studies have been carried out on the biodiversity of the junipers on the island of El Hierro, the current state of their populations, their capacity for regeneration, their possible regression and the actions to be taken to promote their conservation. The main objective of this work was the elaboration of the cartography of the Juniperus turbinata Guss., in the island of El Hierro, from GeoEye-1 images, and to determine the surface and density of individuals. As the obtaining of satellite images produces geometric distortions, they are affected by the atmosphere and by the relief, for that reason the geometric and radiometric corrections were made, which due to the characteristics of the island have been quite laborious. Different vegetation indexes were calculated and the results obtained the correction and classification of the existing vegetation covers are presented. Through historical sources it is known that its extension had been greater, but due to anthropic and environmental factors its surface has been considerably reduced. The results of this investigation allowed to know the current extension and density of the juniper according to the type of juniper, being a fundamental information for the management of the reserve
Juli Caujapecastells - One of the best experts on this subject based on the ideXlab platform.
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phylogeography and genetic structure of the threatened canarian Juniperus cedrus cupressaceae
Botanical Journal of the Linnean Society, 2014Co-Authors: Beatriz Rumeu, Manuel Nogales, Pablo Vargas, Ruth Jaenmolina, Juli CaujapecastellsAbstract:We used plastid sequences (trnL, trnL-trnF, petN-psbM and trnT-trnL) to infer the phylogenetic relationships and inter-island connections of the Canarian Juniperus cedrus, and AFLP fingerprints to assess its genetic diversity patterns. Maximum Likelihood, Maximum Parsimony and Bayesian methods suggest independent colonization events for the three Macaronesian junipers and support the monophyly of J. cedrus. Plastid sequences reveal a low genetic diversity (three haplotypes) and do not provide sufficient information to resolve its temporal and geographical origin. AFLPs indicate a greater isolation in J. cedrus than in other Macaronesian trees with similar distributions and dispersal syndromes. Gran Canaria harbours the least genetically diverse population, which justifies immediate conservation actions. This island and Tenerife also show independent genetic structure, meaning that genetic exchange from other islands should be avoided in eventual reinforcements. Populations from La Palma and La Gomera show the highest genetic diversity levels and number of polymorphic AFLPs, probably because a lower incidence of felling has allowed a less dramatic influence of genetic bottlenecks. We suggest that management efforts should prioritize populations from these islands to preserve the evolutionary potential of the species, but we also stress the importance of knowledge of the evolutionary history, genetic structure and ecological interactions in conservation strategies. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 175, 376–394.
Tigst Demeke - One of the best experts on this subject based on the ideXlab platform.
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systematic relationships in Juniperus based on random amplified polymorphic dnas rapds
Taxon, 1993Co-Authors: Robert P. Adams, Tigst DemekeAbstract:44 taxa of Juniperus were analysed using RAPDs, similarity measures and principal coordinate analyses (PCO). The three sections of Juniperus (sect. Caryocedrus, sect. Juniperus, sect. Sabina) were found to be distinguished by RAPDs. The genus appears to be naturally divided into three major sections with two series (serrate and smooth leaf margins) in J. sect. Sabina. Additional examinations of specific and infraspecific taxa confirms earlier taxonomic work based on leaf terpenoids. Computer software (PCO3D from R.P.A.) for PCO is introduced for the analysis of RAPDs. RAPDs were found to be of taxonomic use ranging from sectional to varietal levels.
Beatriz Rumeu - One of the best experts on this subject based on the ideXlab platform.
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phylogeography and genetic structure of the threatened canarian Juniperus cedrus cupressaceae
Botanical Journal of the Linnean Society, 2014Co-Authors: Beatriz Rumeu, Manuel Nogales, Pablo Vargas, Ruth Jaenmolina, Juli CaujapecastellsAbstract:We used plastid sequences (trnL, trnL-trnF, petN-psbM and trnT-trnL) to infer the phylogenetic relationships and inter-island connections of the Canarian Juniperus cedrus, and AFLP fingerprints to assess its genetic diversity patterns. Maximum Likelihood, Maximum Parsimony and Bayesian methods suggest independent colonization events for the three Macaronesian junipers and support the monophyly of J. cedrus. Plastid sequences reveal a low genetic diversity (three haplotypes) and do not provide sufficient information to resolve its temporal and geographical origin. AFLPs indicate a greater isolation in J. cedrus than in other Macaronesian trees with similar distributions and dispersal syndromes. Gran Canaria harbours the least genetically diverse population, which justifies immediate conservation actions. This island and Tenerife also show independent genetic structure, meaning that genetic exchange from other islands should be avoided in eventual reinforcements. Populations from La Palma and La Gomera show the highest genetic diversity levels and number of polymorphic AFLPs, probably because a lower incidence of felling has allowed a less dramatic influence of genetic bottlenecks. We suggest that management efforts should prioritize populations from these islands to preserve the evolutionary potential of the species, but we also stress the importance of knowledge of the evolutionary history, genetic structure and ecological interactions in conservation strategies. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 175, 376–394.
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differential seed dispersal systems of endemic junipers in two oceanic macaronesian archipelagos the influence of biogeographic and biological characteristics
Plant Ecology, 2011Co-Authors: Beatriz Rumeu, Rui B Elias, David P Padilla, Catarina Melo, Manuel NogalesAbstract:This article evaluates the seed dispersal systems of two congeneric and endemic fleshy-fruited plants in the context of two relatively close oceanic archipelagos. For this purpose, representative populations of the endangered junipers Juniperus cedrus in the Canary Islands and Madeira, and Juniperus brevifolia in the Azores were studied. Despite both species sharing the same biogeographic region, we set out to test whether different conditions of the islands and biological characteristics of each juniper species determine the distinctive guilds of seed dispersers involved. We assessed the quantitative and qualitative role of the potential frugivores, showing that the wintering Turdus torquatus and the native Turdus merula were the main seed dispersers for J. cedrus and J. brevifolia, respectively (Frequency of occurrence: 74.9%, 80.2%; germination increase with respect to controls: 11.6%, 15.5%; for J. cedrus and J. brevifolia, respectively). The endemic lizard Gallotia galloti was quantitatively outstanding as seed disperser of J. cedrus, although its qualitative effect does not appear to be beneficial. The introduced rabbit Oryctolagus cuniculus acts as a disruptor in both natural seed dispersal systems, as inferred from the high percentage of damaged seeds found in their droppings. Our results indicate that J. cedrus and J. brevifolia are primarily adapted to ornithochory processes, T. torquatus and T. merula being their respective legitimate long-distance dispersers. Although these birds should be playing a key role in the connectivity of fragmented populations, the dependence of J. cedrus on a migrant bird involves a notable fragility of the system.
