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1.
Bot Stud ; 65(1): 21, 2024 Jul 16.
Article in English | MEDLINE | ID: mdl-39012376

ABSTRACT

BACKGROUND: Endemism is essential in biodiversity, biogeography, and conservation tasks. Based on herbarium specimens kept in some local herbaria, many published literature, and available information, we compiled a comprehensive list and an updated assessment of the Egyptian endemic and near-endemic taxa. The application of quantitative approaches to the distribution patterns, conservation status, and habitat preference of endemic taxa in Egypt was provided. Comparisons of the near-endemic taxa with other neighbouring flora were explained. For each taxon, the distribution patterns, most preferable habitat, biological spectrum, and taxa among 14 phytogeographical regions (Operational Geographical Units; OGUs) of Egypt were determined. RESULTS: In this study, 19 endemics (out of 70) and 76 near-endemics (out of 181) are newly added taxa. Differentiation indices represented the taxonomic degrees of differentiation among endemic taxa. Two different indices were used to assess endemism: single-region endemic taxa (SRET) and multiple-region endemic taxa (MRET). Most endemic and near-endemic taxa were recorded from the mountainous Sinai (S) and the Mareotis sector of the Mediterranean coastal land (Mm). Generally, the most represented families in endemic and near-endemic areas were Asteraceae, Caryophyllaceae, Lamiaceae, and Fabaceae. More than 60% of the endemic taxa occurred in the sandy plains, wadis (desert valleys), and rocky plains and mountains. Applying hierarchical cluster analysis to the occurrences of 70 endemic taxa in the 14 studied OGUs revealed five main floristic groups (I-V), each characterized by certain OGUs. We provided eight groups of near-endemic taxa that represented their extension in neighbouring countries. CONCLUSIONS: The presented data will help to fill the gap in our knowledge of endemism, provide baseline information to understand biogeographical processes and facilitate further cooperation toward conservation purposes.

2.
Article in English | MEDLINE | ID: mdl-38888215

ABSTRACT

Since its coinage ca. 1850 AD by Philip Barker Webb, the biogeographical region of Macaronesia, consisting of the North Atlantic volcanic archipelagos of the Azores, Madeira with the tiny Selvagens, the Canaries and Cabo Verde, and for some authors different continental coastal strips, has been under dispute. Herein, after a brief introduction on the terminology and purpose of regionalism, we recover the origins of the Macaronesia name, concept and geographical adscription, as well as its biogeographical implications and how different authors have positioned themselves, using distinct terrestrial or marine floristic and/or faunistic taxa distributions and relationships for accepting or rejecting the existence of this biogeographical region. Four main issues related to Macaronesia are thoroughly discussed: (i) its independence from the Mediterranean phytogeographical region; (ii) discrepancies according to different taxa analysed; (iii) its geographical limits and the role of the continental enclave(s), and, (iv) the validity of the phytogeographical region level. We conclude that Macaronesia has its own identity and a sound phytogeographical foundation, and that this is mainly based on three different floristic components that are shared by the Macaronesian core (Madeira and the Canaries) and the outermost archipelagos (Azores and Cabo Verde). These floristic components are: (i) the Palaeotropical-Tethyan Geoflora, formerly much more widely distributed in Europe and North Africa and currently restricted to the three northern archipelagos (the Azores, Madeira and the Canaries); (ii) the African Rand Flora, still extant in the coastal margins of Africa and Arabia, and present in the southern archipelagos (Madeira, the Canaries and Cabo Verde), and (iii) the Macaronesian neoendemic floristic component, represented in all the archipelagos, a result of allopatric diversification promoted by isolation of Mediterranean ancestors that manage to colonize Central Macaronesia and, from there, the outer archipelagos. Finally, a differentiating floristic component recently colonized the different archipelagos from the nearest continental coast, providing them with different biogeographic flavours.

3.
Plants (Basel) ; 13(10)2024 May 12.
Article in English | MEDLINE | ID: mdl-38794406

ABSTRACT

Disentangling how climate oscillations and geographical events significantly influence plants' genetic architecture and demographic history is a central topic in phytogeography. The deciduous ancient tree species Ulmus macrocarpa is primarily distributed throughout Northern China and has timber and horticultural value. In the current study, we studied the phylogenic architecture and demographical history of U. macrocarpa using chloroplast DNA with ecological niche modeling. The results indicated that the populations' genetic differentiation coefficient (NST) value was significantly greater than the haplotype frequency (GST) (p < 0.05), suggesting that U. macrocarpa had a clear phylogeographical structure. Phylogenetic inference showed that the putative chloroplast haplotypes could be divided into three groups, in which the group Ⅰ was considered to be ancestral. Despite significant genetic differentiation among these groups, gene flow was detected. The common ancestor of all haplotypes was inferred to originate in the middle-late Miocene, followed by the haplotype overwhelming diversification that occurred in the Quaternary. Combined with demography pattern and ecological niche modeling, we speculated that the surrounding areas of Shanxi and Inner Mongolia were potential refugia for U. macrocarpa during the glacial period in Northern China. Our results illuminated the demography pattern of U. macrocarpa and provided clues and references for further population genetics investigations of precious tree species distributed in Northern China.

4.
Proc Biol Sci ; 290(1990): 20221079, 2023 01 11.
Article in English | MEDLINE | ID: mdl-36629112

ABSTRACT

Devonian plants in Siberia present protracted pioneer succession. Research into the survivorship dynamics of early plant communities upon the palaeocontinent Angarida have demonstrated that transgression and volcanogenic nutrient influx were key to the survival of colonizing plants. Taxic proportions show that migrating taxa entered Angarida from the southwest, Kuznetsk and Minusinsk basins, dispersing across the continent in waves through central areas northwards. The patterns of dispersal are consistent throughout the Devonian. Increased nutrient load from the active pulses of the Viluy-Yakutsk Large Igneous Province, biogeomorphic ecosystem engineering and the increased biomass of Angaridan plants are assisted by Late Devonian transgression. These cumulative factors can be linked to the Late Devonian marine extinctions observed in Siberia.


Subject(s)
Ecosystem , Survivorship , Fossils , Plants , Biomass
5.
Plant Divers ; 45(6): 732-747, 2023 Nov.
Article in English | MEDLINE | ID: mdl-38197003

ABSTRACT

Pinus is an economically and ecologically important genus whose members are dominant components globally in low-latitude mountainous and mid-latitude temperate forests. Pinus species richness is currently concentrated in subtropical mid-low latitudes of the Northern Hemisphere, differing from the latitudinal diversity gradient mostly recognized in woody angiosperms. How the present pattern was developing in Earth's past is still poorly studied, particularly in eastern Asia. Here, a new fossil species, Pinus shengxianica sp. nov. is described based on a fossil seed cone from the Late Miocene Shengxian Formation in Zhejiang, southeast China. A co-occurring cone is recognized as a known fossil species, Pinus speciosa Li. Extensive comparison of extant and fossil members of Pinus suggests P. shengxianica shares a striking cone similarity to Pinus merkusii and Pinus latteri (subsection Pinus) from tropical Southeast Asia in having annular bulges around the umbo on the apophysis. The morphological resemblance indicates these two extant low-latitude pines probably possess a close affinity with the present newly-discovered P. shengxianica and originated from East Asian mid-low latitude ancestors during this generic re-diversification in the Miocene. This scenario is consistent with the evolutionary trajectory reflected by the pine fossil history and molecular data, marking the Miocene as a key period for the origin and evolution of most extant pines globally. The co-occurrences of diverse conifers and broadleaved angiosperms preferring diverse niches demonstrate Late Miocene eastern Zhejiang was one of the hot spots for coniferophyte diversity and hosted a needled-broadleaved mixed forest with complex vegetation structure and an altitudinal zonation.

6.
Plants (Basel) ; 11(19)2022 Sep 30.
Article in English | MEDLINE | ID: mdl-36235455

ABSTRACT

Four species of moss genus Schistidium are reported for the first time from China. All of them have been found in the Xinjiang Uyghur Autonomous Region. Ecological and distributional details of the newly recorded species are provided and their local distribution is mapped. Photographs of the species are attached. Checklist of Schistidium species and identifying key are added. Considering the present records, Schistidium consists of 15 species in China.

7.
Biology (Basel) ; 11(9)2022 Sep 07.
Article in English | MEDLINE | ID: mdl-36138805

ABSTRACT

Comptonia (Myricaceae) is well known as a monotypic genus living only in eastern North America; however, fossils show that the genus occurred extensively in the Northern Hemisphere during the Cenozoic. We observed dozens of Comptonia leaf fossils from the early Miocene in Zhuozi, China. The leaf architecture characteristics and epidermal features of the fossil specimens are described in detail here for the first time, and they were assigned to a new species: Comptonia hirsuta. The fruit fossils collected simultaneously from the same layer were assigned to Comptonia tymensis. The global fossil records indicate that the spatial distribution range of Comptonia reached its peak in both the Eocene and Miocene as two warm periods and then gradually decreased in the Oligocene, as well as after the late Miocene, because of the cooling global climate. Furthermore, the Comptonia taxon in East Asia may have migrated from North America via the Bering route in the late Paleocene or Eocene. Plant exchange between western Europe and eastern North America possibly occurred during the Eocene via the Thulean route. Phytogeographic variation in the Comptonia fossils from China also indicates that the reason for the disappearance of Comptonia from China may not only be due to the prolonged cooling and drying after the late Miocene, but also due to its progenitive pattern.

8.
Pathogens ; 11(9)2022 Sep 05.
Article in English | MEDLINE | ID: mdl-36145448

ABSTRACT

Equid herpesvirus (EHV) is a contagious viral disease affecting horses, causing illness characterized by respiratory symptoms, abortion and neurological disorders. It is common worldwide and causes severe economic losses to the equine industry. The present study was aimed at investigating the incidence of EHVs, the genetic characterization of Tunisian isolates and a spatiotemporal study, using 298 collected samples from diseased and clinically healthy horses. The global incidence of EHV infection was found to be about 71.81%. EHV2 and EHV5 were detected in 146 (48.99%) and 159 (53.35%) sampled horses, respectively. EHV1 was detected in 11 samples (3.69%); EHV4 was not detected. Co-infections with EHV1-EHV2, EHV1-EHV5 and EHV2-EHV5 were observed in 0.33%, 1.34% and 31.54% of tested horses, respectively. Phylogenetic analyses showed that gB of EHV2 and EHV5 displays high genetic diversity with a nucleotide sequence identity ranging from 88 to 100% for EHV2 and 97.5 to 100% for EHV5. Phylogeography suggested Iceland and USA as the most likely countries of origin of the Tunisian EHV2 and EHV5 isolates. These viruses detected in Tunisia seemed to be introduced in the 2000s. This first epidemiological and phylogeographic study is important for better knowledge of the evolution of equid herpesvirus infections in Tunisia.

9.
Plants (Basel) ; 11(12)2022 Jun 17.
Article in English | MEDLINE | ID: mdl-35736747

ABSTRACT

Marsupella sect. Stolonicaulon is not speciose and is a commonly neglected section within the genus, which currently includes three species with somewhat similar morphologies (wiry shoots with distanced leaves) and distributions in the mountains of tropical and subtropical regions (SE (Southeast) Asia, the Venezuelan Andes, and the high mountains of SE Brazil). After studying materials that were found to be dissimilar to the "traditional" Marsupella that were collected in the last decade by the authors of this article, it was found that these plants belong to three new-for-science species, and all of these species should be included in Marsupella sect. Stolonicaulon. The newly described species have expanded the boundaries of morphological variability, not only for the section itself, but also for the genus based on two findings: (1) the leaves of Marsupella sect. Stolonicaulon can be either appressed and entire or spaced and deeply divided (thus, the plants could occasionally be similar to Cephaloziella or Anastrophyllum); (2) some species of the section possess regular underleaf production. The first discovery of regular underleaves in Marsupella, as noted in two of the three newly described taxa, is the main morphological novelty described in this paper. The development of regular underleaves is a presumable relict character that brings Marsupella closer to Nardia, which was recently transferred to the Gymnomitriaceae and occupies an isolated position within its own subfamily, Nardioideae.

10.
Ecol Evol ; 11(18): 12872-12881, 2021 Sep.
Article in English | MEDLINE | ID: mdl-34594545

ABSTRACT

Research on species richness patterns and the advanced elevational Rapoport rule (ERR) has been widespread in recent years; however, there is a lack of such research for the temperate mountainous regions in northeast Asia. Here, we collected plant species from the Seorak Mountain in northeast Asia through field surveys. The species were divided into 11 groups according to the life-form types and phytogeography affinities of each species. The ERR was evaluated using Steven's method and by examining the species richness patterns of each group. The species richness patterns revealed a positive multimodal pattern along the elevation gradient, but phytogeography affinities (increasing trend) and life-form analysis (unimodal) exhibited different patterns. The elevation gradients (1,350 m for the mean elevation-range relationships), which are affected by the boundary effect and different life forms, did not consistently support the ERR. However, herbs as well as rare, endemic, and red list species showed consistent support for the ERR, which could be attributed to the influence by phytogeography affinities. Therefore, the results from Seorak Mountain showed that the ERR was not consistent for different plant life forms in the same area; however, phytogeography affinities could support and explain ERR.

11.
PhytoKeys ; 176: 131-226, 2021.
Article in English | MEDLINE | ID: mdl-33958943

ABSTRACT

The liverwort and hornwort flora of the Korean Peninsula possesses some unique traits arising from the geographic position of the Peninsula, where the mainland flora meets insular flora. This flora is still not exhaustively studied, due not only to political reasons, but also because much less attention has been paid than to adjacent lands by hepaticologists. A checklist presented is based on a study of ca. 15,500 specimens collected by the authors and a review of relevant literature. This study provides the checklist of liverworts and hornworts known from Korea and the geographical distribution of each species within the peninsula. The liverworts and hornworts in Korean flora include 346 taxa (326 species, 16 subspecies and four varieties) in 112 genera and 50 families. Since 2007, 75 taxa of liverworts and four taxa of hornworts are reported as new to the Korean Peninsula, with a number of the new records arising following application of new taxonomic concepts that have become apparent over the last few decades. While compiling the checklist, 42 species, previously reported to Korea, are excluded from the Korean liverwort flora.

12.
Plants (Basel) ; 10(3)2021 Mar 08.
Article in English | MEDLINE | ID: mdl-33800249

ABSTRACT

A total of 46 species and two varieties of the traditionally interpreted genus Orthotrichum are currently known to occur in China. They represent five genera, including Orthotrichum (29 species), Lewinskya (14 species and two varieties), and Nyholmiella and Leratia that are represented by a single species each. The fifth genus Florschuetziella, also consisting of only one species, F. scaberrima, is an entirely neglected representative of the China's moss flora. A list of all accepted taxa is presented and for each taxon all literature records and herbarium specimens are enumerated for provinces in which they have been recorded, and their distribution is mapped. A key to determination of Chinese orthotrichalean mosses is presented. A chronological list of 63 species and varieties and two designations, O. catagonioides and O. microsporum which have never been validly published, reported from China in the years 1892-2020 is presented. Four species, Orthotrichum brasii, O. hooglandii, O. elegans and O. gymnostomum are excluded from the bryoflora of China and Lewinskya affinis var. bohemica and Orthotrichum schimperi are recorded for the first time from this country. Phytogeography of the Chinese taxa of the orthotrichalean mosses is considered and they are grouped into eight phytogeographical elements and five sub-elements.

13.
Biodivers Data J ; 9: e65199, 2021.
Article in English | MEDLINE | ID: mdl-33841022

ABSTRACT

The liverwort flora of Ayan was first investigated one hundred and fifty years after the first exploration of vascular plants. A number of factors has determined the relatively high taxonomic diversity of liverworts in this hemiarctic flora of small-sized area: 118 species and one subspecies were revealed. These data are new not only for the studied area, but also for the huge land adjacent to the western coast of the Sea of Okhotsk. The liverwort flora possesses the domination of taxa common in the hemiarctic, although with a lot of taxa more common in boreal as well as arctic-alpine environments. The presence of Mega-Beringian and calciphilous taxa is the peculiar trait of the studied liverwort flora. Based on detrended correspondence analysis (DCA), Ayan liverwort flora shows relationships to the continental mainland floras situated both in North-East Asian hemiarctic and hemiboreal East Asia and is, therefore, the link between both. The flora of Ayan surroundings is one of the newly-filled 'blank spots' in the possible floral exchange way between Arctic Northeast Asia and mountainous floras of temperate East Asia.

14.
Front Pharmacol ; 11: 561248, 2020.
Article in English | MEDLINE | ID: mdl-33132909

ABSTRACT

The evaluation and confirmation of healing properties of several plant species of genus Terminalia based on their traditional uses and the clinical claims are of utmost importance. Genus Terminalia has received more attention to assess and validate the therapeutic potential and clinical approval due to its immense folk medicinal and traditional applications. Various species of Terminalia genus are used in the form of herbal medicine and formulations, in treatment of diseases, including headache, fever, pneumonia, flu, geriatric, cancer, to improve memory, abdominal and back pain, cough and cold, conjunctivitis, diarrhea, heart disorder, leprosy, sexually transmitted diseases, and urinary tract disorders. These are reported to possess numerous biological properties, counting: antibacterial, antifungal, antiinflammatory, antiviral, antiretroviral, antioxidant, and antipa7rasitic. This current research review aims to update the detailed biological activities, pre-clinical and clinical studies of various extracts and secondary metabolites from several plant species under the genus Terminalia, along with information on the traditional uses and chemical composition to develop a promising strategy for their potential applications in the form of medicine or use in modern drug formulations for treating diseases like pneumonia, flu, and other types of viral infections or controlling human contagions.

15.
Mar Environ Res ; 162: 105153, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33011583

ABSTRACT

Guanabara Bay, the second largest bay on the Brazilian coast, has tropical to subtropical, hypereutrophic water conditions. A survey of the macroalgae flora conducted over the past 200 years (1800-2013) yielded a list of 245 species, which represents 15.7% of the total macroalgae recorded in the Tropical Western Atlantic, while comprehends 29.9% and 50.2% of the marine flora in Brazil and Rio de Janeiro, respectively. When evaluating the macroalgal list throughout different periods, it is noticeable the gradual loss of biodiversity as anthropization increased over the last two centuries. The use of phytogeographic indexes and beta diversity confirmed the negative changes in macroalgae assemblages as a response to increasing environmental degradation. The use of floristic surveys to establish the reference conditions employing historical data and/or regionally referenced prove to be an efficient tool using macroalgae as an ecological indicator for water quality.


Subject(s)
Seaweed , Bays , Biodiversity , Brazil , Ecosystem
16.
PhytoKeys ; 145: 63-92, 2020.
Article in English | MEDLINE | ID: mdl-32327927

ABSTRACT

Records of new species of vascular plants in Greenland from the last four decades are presented and new phytogeographical data leading to extension of the known distribution limits in Greenland are discussed. Since the publication of the latest edition of the Flora of Greenland in 1978 (Böcher et al. 1978) fieldwork by Greenland Botanical Survey and other expeditions have taken place especially in West and East Greenland and in many remote areas in North and Northeast Greenland. This paper serves as an update of the Flora of Greenland. Twenty species, one subspecies and one new forma have been added to the flora of Greenland: Carex membranacea Hook., Carex miliaris Michx., Carex rhomalea (Fernald) Mack., Equisetum hyemale L., Festuca edlundiae S. Aiken, Consaul and Lefkovich, Festuca groenlandica (Schol.) Frederiksen, Festuca saximontana Rydb., Galium verum L., Geum rossii (R. Br.) Ser., Papaver cornwallisense D. Löve, Papaver dahlianum Nordh., Papaver labradoricum (Fedde) Solstad and Elven, Papaver lapponicum (Tolm.) Nordh., Pedicularis sudetica Willd. ssp. albolabiata Hult., Poa flexuosa Sm., Puccinellia bruggemanni Th. Sør., Ranunculus subrigidus W.B. Drew., Silene vulgaris (Moench) Garcke, Trientalis europaea L. and Veronica officinalis L. in addition to one subspecies Phippsia algida (Sol.) R. Br. ssp. algidiformis (H. Sm.) Löve and Löve. The viviparous form of Poa hartzii f. prolifera has been reported for the first time in Greenland. Presently, the total number of vascular plant species in Greenland is 532. 89 new northern and 28 new southern distribution limits are presented and 26 species are new to the flora province East Greenland, whereas 15 species are new to West Greenland. The numbers of new species to flora provinces North and South Greenland are 14 and one, respectively.

17.
PeerJ ; 7: e7336, 2019.
Article in English | MEDLINE | ID: mdl-31396438

ABSTRACT

In Mediterranean-Climate Ecosystems (MCEs), Holocene coastal dunes comprise small, fragmented and dynamic features which have nutritionally imbalanced and excessively drained, droughty, sandy soils. These characteristics, along with summer drought and salt-laden winds, pose many challenges for plant colonization and persistence. Consequently, MCE dune floras are likely to be distinctive with a high proportion of habitat specialists and strong convergence in growth form mixes. Very little research has compared the species traits of dune floras within and across MCEs. This paper contributes to filling that gap. Here, we analyze the taxonomic, biological and geographical traits for all 402 species in a flora from a dune landscape (Cape St Francis) in the southeastern Cape Floristic Region (CFR) and compare patterns with the trait profiles of other dune floras at a regional (CFR) and global (MCE) scale. Within the CFR, the southeastern (all-year-rainfall) flora at Cape St Francis had a similar trait profile to western (winter-rainfall) dune floras, except for having a lower representation of species belonging to CFR-endemic clades, and higher number of species associated with tropical lineages. The St Francis flora, in common with other CFR and MCE floras, was dominated by members of the Asteraceae, Fabaceae and Poaceae. Some 40% of the St Francis flora was endemic to the CFR, typical of the high rate of MCE-level endemism elsewhere in the CFR, and in other MCEs. About 30% of the flora was confined to calcareous sand, a value typical for many other MCE sites. The St Francis flora, as well as other CFR dune floras, differs from those of other MCEs by having many species associated with shrubby lineages, and by the relatively high incidence of species associated with tropical lineages. The growth form profile of the St Francis and other CFR floras shows strongest similarity with that of Australian MCE dunes in that in both regions, evergreen hemicryptophytes and shrubs share dominance, and annuals are floristically and ecologically subordinate. The least similar of MCEs to the St Francis trait profile is the Mediterranean Basin where annuals are the most frequent growth form while shrubs are subordinate. California and Chile dune floras appear to occupy an intermediate position, in terms of growth form mix, between the Cape and Australia on the one hand, where dune floras have retained features typical of nutrient-poor soils, and the Mediterranean Basin, where dwarf, deciduous shrubs and annuals dominate the life form spectrum. All MCE dunes are threatened by alien plants, infrastructure development, tourism demands and rising sea levels. The high incidence of species of conservation concern in CFR dune floras underestimates the exponentially increasing threats to their habitats, which are already historically at a much-reduced extent. All remaining coastal dune habitat in the CFR, and probably in other MCEs, should be conserved in their entirety.

18.
Am J Bot ; 106(1): 154-165, 2019 01.
Article in English | MEDLINE | ID: mdl-30629286

ABSTRACT

PREMISE OF THE STUDY: This investigation establishes the first DNA-sequence-based phylogenetic hypothesis of species relationships in the coca family (Erythroxylaceae) and presents its implications for the intrageneric taxonomy and neotropical biogeography of Erythroxylum. We also identify the closest wild relatives and evolutionary relationships of the cultivated coca taxa. METHODS: We focused our phylogenomic inference on the largest taxonomic section in the genus Erythroxylum (Archerythroxylum O.E.Schulz) using concatenation and gene tree reconciliation methods from hybridization-based target capture of 427 genes. KEY RESULTS: We show that neotropical Erythroxylum are monophyletic within the paleotropical lineages, yet Archerythroxylum and all of the other taxonomic sections from which we sampled multiple species lack monophyly. We mapped phytogeographic states onto the tree and found some concordance between these regions and clades. The wild species E. gracilipes and E. cataractarum are most closely related to the cultivated E. coca and E. novogranatense, but relationships within this "coca" clade remain equivocal. CONCLUSIONS: Our results point to the difficulty of morphology-based intrageneric classification in this clade and highlight the importance of integrative taxonomy in future systematic revisions. We can confidently identify E. gracilipes and E. cataractarum as the closest wild relatives of the coca taxa, but understanding the domestication history of this crop will require more thorough phylogeographic analysis.


Subject(s)
Domestication , Erythroxylaceae/genetics , Phylogeny , Phylogeography , South America
19.
PeerJ ; 6: e4786, 2018.
Article in English | MEDLINE | ID: mdl-29868254

ABSTRACT

BACKGROUND: The páramo is a high-elevation biogeographical province in the northern Andes, known for its great biodiversity and ecosystem services. Because there have been very few biogeographic studies encompassing the entire province to date, this study aimed at conducting a phytogeographical regionalisation of the páramo. Specifically, (1) clustering analyses were conducted to identify the main phytogeographical units in the three altitudinal belts: sub-páramo, mid-páramo and super-páramo, and examine their diagnostic flora, (2) an ordination complemented the geo-climatic characterization of the obtained units and (3) a hierarchical classification transformation was obtained to evaluate the relationships between units. METHODS: The study area included the entire Andean páramo range in northern Peru, Ecuador, Colombia and Venezuela. The analyses were based on 1,647 phytosociological plots from the VegPáramo database. The K-means non-hierarchical clustering technique was used to obtain clusters identifiable as phytogeographical units, and the Ochiai fidelity index was calculated to identify their diagnostic species. A principal component analysis was conducted to obtain the geo-climatic characterization of each unit. Finally, the relationships between clusters were traced using a hierarchical plot-based classification. RESULTS: Fifteen clusters were obtained, 13 natural and two artificial, of which two represented the sub-páramo, nine the mid-páramo and four the super-páramo. Even though data representativeness was a potential limitation to segregate certain sub-páramo and super-páramo units, the overall bioregionalisation was robust and represented important latitudinal, altitudinal and climatic gradients. DISCUSSION: This study is the first to bioregionalise the páramo province based on a substantial widely distributed biological dataset, and therefore provides important novel scientific insight on its biogeography. The obtained phytogeographical units can be used to support further research on the páramo at smaller scale and on the humid Neotropical high-elevation ecosystems at broader-scale. Finally, several units were highlighted in our results as particularly worthy of further scientific and conservation focus.

20.
Article in English | MEDLINE | ID: mdl-29930938

ABSTRACT

Pre-commercialization studies on environmental biosafety of genetically modified (GM) crops are necessary to evaluate the potential for sexual hybridization with related plant species that occur in the release area. The aim of the study was a preliminary assessment of factors that may contribute to gene flow from sugarcane (Saccharum hybrids) to indigenous relatives in the sugarcane production regions of Mpumalanga and KwaZulu-Natal provinces, South Africa. In the first instance, an assessment of Saccharum wild relatives was conducted based on existing phylogenies and literature surveys. The prevalence, spatial overlap, proximity, distribution potential, and flowering times of wild relatives in sugarcane production regions based on the above, and on herbaria records and field surveys were conducted for Imperata, Sorghum, Cleistachne, and Miscanthidium species. Eleven species were selected for spatial analyses based on their presence within the sugarcane cultivation region: four species in the Saccharinae and seven in the Sorghinae. Secondly, fragments of the nuclear internal transcribed spacer (ITS) regions of the 5.8s ribosomal gene and two chloroplast genes, ribulose-bisphosphate carboxylase (rbcL), and maturase K (matK) were sequenced or assembled from short read data to confirm relatedness between Saccharum hybrids and its wild relatives. Phylogenetic analyses of the ITS cassette showed that the closest wild relative species to commercial sugarcane were Miscanthidium capense, Miscanthidium junceum, and Narenga porphyrocoma. Sorghum was found to be more distantly related to Saccharum than previously described. Based on the phylogeny described in our study, the only species to highlight in terms of evolutionary divergence times from Saccharum are those within the genus Miscanthidium, most especially M. capense, and M. junceum which are only 3 million years divergent from Saccharum. Field assessment of pollen viability of 13 commercial sugarcane cultivars using two stains, iodine potassium iodide (IKI) and triphenyl tetrazolium chloride, showed decreasing pollen viability (from 85 to 0%) from the north to the south eastern regions of the study area. Future work will include other aspects influencing gene flow such as cytological compatibility and introgression between sugarcane and Miscanthidium species.

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