49 research outputs found

    Rate of lineage origin explains the diversity anomaly in the World’s mangrove vegetation

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    The contribution of nonecological factors to global patterns in diversity is evident when species richness differs between regions with similar habitats and geographic area. Mangrove environments in the Eastern Hemisphere harbor six times as many species of trees and shrubs as similar environments in the New World. Genetic divergence of mangrove lineages from terrestrial relatives, in combination with fossil evidence, suggests that mangrove diversity is limited by evolutionary transition into the stressful marine environment, the number of mangrove lineages has increased steadily over the Tertiary with little global extinction, and the diversity anomaly in mangrove vegetation reflects regional differences in the rate of origin of new mangrove lineages

    A new, flaccid, decurrent leaf variety of Juniperus poblana from Mexico: J. poblana var. decurrens R. P. Adams

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    Analyses of nrDNA and four cp DNAs (petN-psbM, trnS-trnG, trnD-trnT, trnL-trnF) plus morphology and leaf essential oils revealed that the weeping (flaccid), decurrent leafed junipers near Topia, Durango are closely related to J. poblana (formerly J. flaccida var. poblana) and should be recognized as a new variety, J. poblana var. decurrens R. P. Adams var. nov. The leaf oil of J. p. var. decurrens is dominated by α-pinene (53.2%) with moderate amounts of β-pinene (5.3%), myrcene (4.3%), δ-2-carene (1.2%), δ-3-carene (2.5%), limonene (3.2%), β-phellandrene (3.1%), terpinolene (1.0%), (E)-caryphyllene (1.1%), and germacrene D (1.5%) and shares eleven unique terpenes with J. poblana

    Chloroplast capture in Juniperus sabina var. balkanensis R. P. Adams and A. N. Tashev, from the Balkan peninsula: A new variety with a history of hybridization with J. thurifera

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    example of chloroplast capture has been identified in Juniperus sabina from Bulgaria and Greece in the Balkan peninsula. Nuclear DNA and overall morphology clearly indicate a close relationship to Juniperus sabina, whereas the cpDNA from these populations is very uniform and is nearly identical to that of J. thurifera, an unrelated species currently growing in France, Spain and Morocco. The new taxon is recognized as Juniperus sabina var. balkanensis R. P. Adams and A. Tashev. At present, this new variety is known only from locations in Bulgaria and Greece

    Chloroplast capture by a new variety, Juniperus sabina var. balkanensis R. P. Adams and A. N. Tashev, from the Balkan peninsula: A putative stabilized relictual hybrid between J. sabina and ancestral J. thurifera

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    An example of chloroplast capture has been found in Juniperus sabina from Bulgaria and Greece in the Balkan peninsula. The cpDNA from these populations is very uniform and is nearly identical to that of J. thurifera (currently growing in France, Spain and Morocco). The new taxon is recognized as Juniperus sabina var. balkanensis R. P. Adams and A. Tashev. At present, the variety, with the thurifera cpDNA, is known only from Bulgaria and Greece

    Long distance gene flow facilitated by bird-dispersed seeds in wind-pollinated species: A story of hybridization and introgression between Juniperus ashei and J. ovata told by nrDNA and cpDNA

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    nrDNA and cpDNA were sequenced of J. ashei and J. ovata from populations throughout their ranges. No J. ashei populations were found to be pure in their nrDNA for every tree, however all J. ashei trees in every population contained only the pure J. ashei chloroplast type. Populations of J. ovata in trans-Pecos Texas were almost pure in both nrDNA and cp DNA. Several plants in the J. ashei range contained J. ovata-type nrDNA (White Cliffs, AR, 3/10); Ranger, TX (1/5); Waco, TX (1/12). Every J ashei population contained at least 1 plant with hybrid (heterozygous) nrDNA and 3 J. ovata populations contained putative hybrids (by nrDNA), but one population had only pure J. ovata trees. The presence of ovata germplasm within J. ashei populations seems best explained by long distance bird dispersal of J. ovata seeds (thence seedlings and J. ovata trees and hybrids) in the disjunct J. ashei populations. The reason for the absence of ovata paternal cp, which is distributed by pollen in J. ashei populations is not known. Judged by distribution of cp data, there is very little movement of cp genomes. In contrast, nrDNA polymorphisms indicate there is considerable gene flow between J. ashei and J. ovata, but primarily in the direction of J. ovata to J. ashei which may be explained by a combination of bird migration pattern and recurring and preferential F1-hybrid formation

    Chloroplast capture by a new variety, Juniperus sabina var. balkanensis R. P. Adams and A. N. Tashev, from the Balkan peninsula: A putative stabilized relictual hybrid between J. sabina and ancestral J. thurifera

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    An example of chloroplast capture has been found in Juniperus sabina from Bulgaria and Greece in the Balkan peninsula. The cpDNA from these populations is very uniform and is nearly identical to that of J. thurifera (currently growing in France, Spain and Morocco). The new taxon is recognized as Juniperus sabina var. balkanensis R. P. Adams and A. Tashev. At present, the variety, with the thurifera cpDNA, is known only from Bulgaria and Greece

    Phylogeny of Juniperus using nrDNA and four cpDNA regions

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    ABSTRACT 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 o

    Juniperus communis in Azerbaijan: analyses of nrDNA and cpDNA regions

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    Juniperus \u27pygmaea\u27 from Azerbaijan was analyzed by DNA sequence data from nrDNA plus four cp DNA regions (4315 bp) and found in a clade with J. communis \u27oblonga\u27 (= J. communis) Armenia, not with J. c. forma pygmaea of Bulgaria. It seems prudent to not recognize this variant taxonomically but treat it as J. communis

    Genome-wide RAD sequencing resolves the evolutionary history of serrate leaf Juniperus and reveals discordance with chloroplast phylogeny

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    Juniper (Juniperus) is an ecologically important conifer genus of the Northern Hemisphere, the members of which are often foundational tree species of arid regions. The serrate leaf margin clade is native to topologically variable regions in North America, where hybridization has likely played a prominent role in their diversification. Here we use a reduced-representation sequencing approach (ddRADseq) to generate a phylogenomic data set for 68 accessions representing all 22 species in the serrate leaf margin clade, as well as a number of close and distant relatives, to improve understanding of diversification in this group. Phylogenetic analyses using three methods (SVDquartets, maximum likelihood, and Bayesian) yielded highly congruent and well-resolved topologies. These phylogenies provided improved resolution relative to past analyses based on Sanger sequencing of nuclear and chloroplast DNA, and were largely consistent with taxonomic expectations based on geography and morphology. Calibration of a Bayesian phylogeny with fossil evidence produced divergence time estimates for the clade consistent with a late Oligocene origin in North America, followed by a period of elevated diversification between 12 and 5 Mya. Comparison of the ddRADseq phylogenies with a phylogeny based on Sanger-sequenced chloroplast DNA revealed five instances of pronounced discordance, illustrating the potential for chloroplast introgression, chloroplast transfer, or incomplete lineage sorting to influence organellar phylogeny. Our results improve understanding of the pattern and tempo of diversification in Juniperus, and highlight the utility of reduced-representation sequencing for resolving phylogenetic relationships in non-model organisms with reticulation and recent divergence

    Inheritance of single copy nuclear genes (SCNGs) in artificial hybrids of Hesperocyparis arizonica x H. macrocarpa: Potential for utilization in the detection of hybridization in natural populations

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    Analyses were performed on 18 artificial hybrids from a cross of Hesperocyparis arizonica (male parent) x H. macrocarpa (female parent) using 9 single copy nuclear genes (SCNGs). Three SCNG were found to be informative: myb, 4CL and CnAIB2. Gene myb contained 5 variable sites, of which site 89 was homozygous (CC, TT) as was site 261 (GG, AA) and useful for the detection of hybridization. All 18 hybrids were heterozygous (CT and GA) at these 2 sites as predicted in hybrids. 4CL contained 8 variable sites, of which 1 site (591) was homozygous (TT, CC) and all 18 hybrids were heterozygous (TC) at this site as expected. CnAIP2 had two variable sites: 301 (AA, AC) and 554 (AG, AA). For site 301, 8 hybrids were AA, and 10 were AC as expected. For site 554, 10 hybrids were AA and 8 were AG, so neither would be useful for unequivocally identifying hybrids. The inheritance of variable sites for the three SCNGs followed simple co-occurrence. Examination of myb in the 18 hybrids revealed 2 cases of cross-over in the pollen gametes
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