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1.
Although the high diversity of neotropical plants is often associated with rain forests, another important location is open vegetation at mountain tops. In the present study, we investigated the phytogeographic patterns of the Espinhaço Range, in eastern Brazil, a region characterized by campos rupestres and marked by high levels of plant richness and endemism. Based on the occurrence of Asclepiadoideae (Apocynaceae) in a grid of 0.5º × 0.5º cells, we conducted cluster analyses and parsimony analysis of endemicity (PAE). We also calculated indexes of diversity and endemism and examined the distribution of palaeo- and neo-endemics. According to our data, the topographic gap between the Espinhaço Range of Minas Gerais and Bahia seems to be an important constraint for the dispersion of endemics, and the floristic similarity between northern Minas Gerais and Bahia is a result of species with broad distribution. Based on the seven areas of endemism that emerged from PAE, we defined five principal centres of endemism in the Espinhaço Range, including the region comprising Serra do Cipó and the Diamantina Plateau, in Minas Gerais, as the major Asclepiadoideae cradle, and Chapada Diamantina, in Bahia, as an Asclepiadoideae museum.  相似文献   

2.
Field work and data from herbaria collections (2686 records) representing 283 taxa (265 species and 18 infraspecific taxa) of Bromeliaceae occurring at Minas Gerais state, southeastern Brazil, were analyzed in order to obtain distribution and diversity information, and to determine IUCN (The World Conservation Union) conservation status for each taxon. A map containing 1° × 1° grid cells was used to identify priority areas for new research collections, areas of high species diversity, and Bromeliaceae conservation status. A clear decrease in Bromeliaceae diversity is observed between the eastern and the western portions of Minas Gerais, and low floristic similarities were found between neighboring grid cells. The rocky mountains of Cadeia do Espinhaço are considered the most important area for Bromeliaceae endemics. From the 283 taxa of Bromeliaceae that occur at Minas Gerais, 118 (42%) are considered threatened, and 124 taxa (44% of the total) do not occur inside any protected area. The region of the Quadrilátero Ferrífero in the southern portion of the Cadeia do Espinhaço is the most threatened, and urgent strategies for conservation of this rich Bromeliaceae flora are needed. Northeastern Minas Gerais, particularly the rocky outcrops or inselbergs located in the Jequitinhonha and Mucuri rivers drainage basins need additional collection efforts and conservation actions focused on these saxicolous taxa.  相似文献   

3.
Plathymenia foliolosa and P. reticulata are two tropical tree species economically important for their high quality wood. P. foliolosa occurs mainly in areas of Atlantic Forest (a tropical forest) whereas P. reticulata occurs mainly in the Cerrado region (a savanna vegetation), both Brazilian biomes classified as hotspots for conservation priorities. In the present study RAPD markers were used to differentiate P. foliolosa from the vicariant species P. reticulata. Using 10 random primers it was possible to obtain 84 markers, of which 22 (26.2%) were present in just one of the two species. Nine of the ten primers were successful in discriminating between the species through the detection of diagnostic markers or band frequency differences. One of the populations of P. foliolosa, located in a region where the two species co-occur, presented several markers that were characteristic of P. reticulata, suggesting the occurrence of gene flow between the two species. Received September 3, 2001; accepted August 19, 2002 Published online: November 22, 2002 Addresses of the authors: Daniela Rodrigues Lacerda (dlacerda@dedalus.lcc.ufmg.br), Maria Bernadete Lovato (lovatomb@icb.ufmg.br), Maria Dolores Porto Acedo (acedomd@icb.ufmg.br), Dept. Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, CP: 486, Belo Horizonte, MG, 31270-901, Brasil. José Pires de Lemos Filho (lemos@icb.ufmg.br), Dept. Botanica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, CP: 486, Belo Horizonte, MG, 31270-901, Brasil.  相似文献   

4.
Eight novel microsatellite markers were isolated from the woolly mouse opossum from the Amazon Forest in Peru, Micoureus demerarae, using a partial genomic DNA library and an enrichment protocol. These loci were polymorphic in M. demerarae and Micoureus paraguayanus populations from the Atlantic Forest in Brazil with the number of alleles ranging from two to 23. Those eight loci plus another five already described for M. paraguayanus will allow for the evaluation of genetic diversity of populations from the 'Rio Doce' Park, one of the last Atlantic Forest fragments in Minas Gerais state, Brazil.  相似文献   

5.
Lonchocarpus castaneifolius, L. grazielae, L. longiunguiculatus, and L. montanus from Brazil are described and illustrated based on field and herbarium studies. The first species belongs to Lonchocarpus sect. Punctati and is restricted to northeastern Brazil (Bahia state). The other three are included in sect. Laxiflori. Lonchocarpus grazielae is restricted to the southern coastal region (Santa Catarina state), L. montanus is found in northeastern Brazil (Bahia and Piauí states), the west-central region (Goiás and Tocantins states) and the southeast (Minas Gerais state), and L. longiunguiculatus occurs in northeastern (Bahia state) and southeastern (Minas Gerais state) Brazil.  相似文献   

6.
Changes in the sea level during the Holocene are regarded as one of the most prevalent drivers of the diversity and distribution of macroalgae in Brazil, influenced by the emergence of the Vitória-Trindade seamount chain (VTC). Gracilariopsis tenuifrons has a wide geographic distribution along the Brazilian coast, from Maranhão state (2°48′64.3" S) to Santa Catarina state (27.5°73′83" S). The knowledge of historical processes affecting diversity may allow the development of conservation strategies in environments against anthropogenic influence. Therefore, knowledge about phylogeography and populational genetic diversity in G. tenuifrons is necessary. Six populations were sampled along the northeastern tropical (Maranhão—MA, Rio Grande do Norte—RN, Alagoas—AL, and Bahia—BA States) and southeastern subtropical (São Paulo “Ubatuba”—SP1 and São Paulo “Itanhaém”—SP2 States) regions along the Brazilian coast. The genetic diversity and structure of G. tenuifrons were inferred using mitochondrial (COI-5P and cox2-3 concatenated) DNA markers. Gracilariopsis tenuifrons populations showed an evident separation between the northeast (from 2°48′64.3" S to 14°18′23" S; 17 haplotypes) and the southeast (from 23°50′14.9" S to 24°20′04.7" S; 10 haplotypes) regions by two mutational steps between them. The main biogeographical barrier to gene flow is located nearby the VTC. The southeast region (São Paulo State) is separated by two subphylogroups (SP1, three haplotypes and SP2, six haplotypes), and Santos Bay (estuary) has been considered a biogeographical barrier between them. The presence of genetic structure and putative barriers to gene flow are in concordance with previous studies reporting biogeographic breaks in the southwest Atlantic Ocean, including the genetic isolation between northeast and southeast regions for red and brown algae in the vicinity of the VTC.  相似文献   

7.
The Pucciniomycete fungus Hemileia vastatrix causes leaf rust on coffee trees. The pathogen is responsible for considerable yield losses in susceptible coffee cultivars if appropriate management strategies are not implemented. Rapid spread and epidemics of rust fungi are usually associated with the emergence of new races of the pathogen that overcome resistance or with the emergence of more aggressive populations of the pathogen. In Brazil, coffee production is dominated by susceptible cultivars of Coffea arabica and Coffea canephora. We assessed aggressiveness in 46 populations of Hvastatrix from Minas Gerais and Espírito Santo, two of the most important coffee‐producing states in Brazil. We observed a significant difference in the incubation period between the populations from Minas Gerais and Espírito Santo when 183 single‐pustule isolates were inoculated onto Catuaí Vermelho IAC 44, a susceptible C. arabica cultivar. Variation in aggressiveness components was observed between and within localities. Isolates with longer incubation periods also tended to have longer latent periods, although there was only a low correlation between these two aggressiveness components (r2 = 0.34, P = 2.2 × 10?16). Low‐sporulating isolates also had significantly longer incubation and latent periods. The H. vastatrix population from Minas Gerais and Espírito Santo is structured by the formation of groups of individuals with differential level of aggressiveness. Our results indicate that the variation in aggressiveness of the Brazilian H. vastatrix population may be associated with the geographic coffee‐producing areas.  相似文献   

8.
This paper reports on molecular classification of the woolly mouse opossum, Micoureus spp., in the southeastern Atlantic Forest in Brazil, a hotspot of critically threatened biodiversity. Phylogenetic analysis and character-based diagnosis were done using DNA sequences from the mitochondrial cytochrome b gene and cytochrome c oxidase subunit I genes, and exon 6 of the nuclear dentine matrix protein 1 gene (DMP1). Although the nuclear DMP1 gene showed insufficient genetic variation for species diagnosis, the mtDNA analyses resulted in the robust grouping of samples of the M. paraguayanus/M. demerarae complex into three clades with distinct DNA sequence diagnostics for the species units in this study. The results support the species status of M. paraguayanus (Tate in Am Mus Novit 493: 1–13, 1931), which has a geographic distribution in the Atlantic Forest from the North and Northeast of Minas Gerais state in Brazil, going south along the coastal region of Brazil, to Paraguay and Argentina. Evidence of the boundary for this species and the provided diagnostics should facilitate and improve accuracy of studies that have been done in critical threatened fragments of the Atlantic Forest, especially in Minas Gerais and Bahia states, Brazil.  相似文献   

9.
Aim We examined the phylogeography of the cold‐temperate macroalgal species Fucus distichus L., a key foundation species in rocky intertidal shores and the only Fucus species to occur naturally in both the North Pacific and the North Atlantic. Location North Pacific and North Atlantic oceans (42° to 77° N). Methods We genotyped individuals from 23 populations for a mitochondrial DNA (mtDNA) intergenic spacer (IGS) (n = 608) and the cytochrome c oxidase subunit I (COI) region (n = 276), as well as for six nuclear microsatellite loci (n = 592). Phylogeographic structure and connectivity were assessed using population genetic and phylogenetic network analyses. Results IGS mtDNA haplotype diversity was highest in the North Pacific, and divergence between Pacific haplotypes was much older than that of the single cluster of Atlantic haplotypes. Two ancestral Pacific IGS/COI clusters led to a widespread Atlantic cluster. High mtDNA and microsatellite diversities were observed in Prince William Sound, Alaska, 11 years after severe disturbance by the 1989 Exxon Valdez oil spill. Main conclusions At least two colonizations occurred from the older North Pacific populations to the North Atlantic between the opening of the Bering Strait and the onset of the Last Glacial Maximum. One colonization event was from the Japanese Archipelago/eastern Aleutians, and a second was from the Alaskan mainland around the Gulf of Alaska. Japanese populations probably arose from a single recolonization event from the eastern Aleutian Islands before the North Pacific–North Atlantic colonization. In the North Atlantic, the Last Glacial Maximum forced the species into at least two known glacial refugia: the Nova Scotia/Newfoundland (Canada) region and Andøya (northern Norway). The presence of two private haplotypes in the central Atlantic suggests the possibility of colonization from other refugia that are now too warm to support F. distichus. With the continuing decline in Arctic ice cover as a result of global climate change, renewed contact between North Pacific and North Atlantic populations of Fucus species is expected.  相似文献   

10.
A new family of Laniatores, Gerdesiidae fam. nov., is proposed based on molecular and morphological evidence. Data also indicate that this new family is the sister family of Tricommatidae. Gerdesiidae fam. nov. has a disjunct distribution, occurring in northern South America (Peru, Brazilian Amazon) and at a spot in south‐eastern Brazil (Minas Gerais State). The new family is composed of two genera: Gerdesius Roewer, 1952 (type genus) and G onycranaus gen. nov. (type species G onycranaus androgynus sp. nov. ). We propose the synonymy of Huralvioides H. Soares, 1970 with Gerdesius Roewer, 1952 based on molecular and morphological evidence. Three new species are described: G erdesius mapinguari sp. nov. (type locality: Brazil, Amazonas, Manaus, Reserva Km 41); G onycranaus androgynus sp. nov. (type locality: Brazil, Minas Gerais, Conceição do Mato Dentro); and an obligate cave‐dwelling species, G onycranaus pluto sp. nov. (type locality: Brazil, Minas Gerais, Morro do Pilar). © 2015 The Linnean Society of London  相似文献   

11.
Macaúba (Acrocomia aculeata) is a palm of economic importance, widely distributed in natural forests from Mexico to Uruguay. We analyzed the genetic diversity of populations of macaúba (A. aculeata) in the northern region of the State of Minas Gerais, Brazil. Young leaves from 10 macaúba individuals encompassing 49 genotypes of macaúba were collected from Montes Claros, Itacambira, Brasília de Minas, Mirabela, and Gr?o Mogol. After extraction and amplification of samples, the amplified fragments were separated by electrophoresis. We found high levels of genetic diversity within the populations. Genetic diversity indices were high, except in the Itacambira and Mirabela populations. Results show that Mirabela and Itacambira populations can require conservation strategies because they present lower values of genetic diversity.  相似文献   

12.
The objective of this study was to map the spatial distribution of aboveground carbon stock (using Regression-kriging) of arboreal plants in the Atlantic Forest, Semi-arid woodland, and Savanna Biomes in Minas Gerais State, southeastern Brazil. The database used in this study was obtained from 163 forest fragments, totaling 4,146 plots of 1,000 m2 distributed in these Biomes. A geographical model for carbon stock estimation was parameterized as a function of Biome, latitude and altitude. This model was applied over the samples and the residuals generated were mapped based on geostatistical procedures, selecting the exponential semivariogram theoretical model for conducting ordinary Kriging. The aboveground carbon stock was found to have a greater concentration in the north of the State, where the largest contingent of native vegetation is located, mainly the Savanna Biome, with Wooded Savanna and Shrub Savanna phytophysiognomes. The largest weighted averages of carbon stock per hectare were found in the south-center region (48.6 Mg/ha) and in the southern part of the eastern region (48.4 Mg/ha) of Minas Gerais State, due to the greatest predominance of Atlantic Forest Biome forest fragments. The smallest weighted averages per hectare were found in the central (21.2 Mg/ha), northern (20.4 Mg/ha), and northwestern (20.7 Mg/ha) regions of Minas Gerais State, where Savanna Biome fragments are predominant, in the phytophysiognomes Wooded Savanna and Shrub Savanna.  相似文献   

13.
Inferring how the Pleistocene climate oscillations have repopulated the extant population structure of Chondrus crispus Stackh. in the North Atlantic Ocean is important both for our understanding of the glacial episode promoting diversification and for the conservation and development of marine organisms. C. crispus is an ecologically and commercially important red seaweed with broad distributions in the North Atlantic. Here, we employed both partial mtDNA Cox1 and nrDNA internal transcribed spacer region 2 (ITS2) sequences to explore the genetic structure of 17 C. crispus populations from this area. Twenty‐eight and 30 haplotypes were inferred from these two markers, respectively. Analysis of molecular variance (AMOVA) and of the population statistic ΦST not only revealed significant genetic structure within C. crispus populations but also detected significant levels of genetic subdivision among and within populations in the North Atlantic. On the basis of high haplotype diversity and the presence of endemic haplotypes, we postulate that C. crispus had survived in Pleistocene glacial refugia in the northeast Atlantic, such as the English Channel and the northwestern Iberian Peninsula. We also hypothesize that C. crispus from the English Channel refugium repopulated most of northeastern Europe and recolonized northeastern North America in the Late Pleistocene. The observed phylogeographic pattern of C. crispus populations is in agreement with a scenario in which severe Quaternary glaciations influenced the genetic structure of North Atlantic marine organisms with contiguous population expansion and locally restricted gene flow coupled with a transatlantic dispersal in the Late Pleistocene.  相似文献   

14.
Amblyomma sculptum (Ixodida: Ixodidae) Berlese, 1888 is the most important tick vector in Brazil, transmitting the bioagent of the most severe form of spotted fever (SF) in part of the Cerrado (in the states of Minas Gerais and São Paulo). In another part of the Cerrado (Central‐West region of Brazil), a milder form of SF has been recorded. However, neither the rickettsia nor the vector involved have been characterized. The aim of the current study was to analyse genetic variation and the presence of rickettsia in A. sculptum in Cerrado, from silent areas and with the milder form of SF. Samples were subjected to DNA extraction, amplification and sequencing of 12S rDNA, cytochrome oxidase subunit II and D‐loop mitochondrial genes (for tick population analyses), and gltA, htrA, ompA and gene D (sca4) genes for rickettsia researches. Exclusive haplotypes with low frequencies, high haplotype diversity and low nucleotide diversity, star‐shaped networks and significant results in neutrality tests indicate A. sculptum population expansions in some areas. Rickettsia amblyommatis, Candidatus Rickettsia andeanae and Rickettsia felis were detected. The A. sculptum diversity is not geographically, or biome delimited, pointing to a different potential in vector capacity, possibly associated with differing tick genetic profiles.  相似文献   

15.
Previous studies suggested that the biodiversity of the mangrove‐associated Bostrychia radicans/Bostrychia moritziana species complex on the Pacific coast of Central America, based on genetic and reproductive data, were low compared with similar areas on the Atlantic coast. Evolutionary scenarios were proposed based on either a recent introduction to the Pacific, or a more uniform environment leading to genetically connected populations and low differentiation between populations. We sampled more extensively in southern Mexico, Guatemala and El Salvador and sequenced the samples for the RuBisCo spacer. Our results show that genetic diversity is high in these populations. Many haplotypes retrieved are also found in the Atlantic Ocean (USA, Brazil), an observation not made before. Data suggest that populations are highly differentiated with little evidence of isolation‐by‐distance. The population at La Puntilla, El Salvador is highly differentiated from other populations. Data also suggest that diversity is reduced in a northerly direction, with only one haplotype, unique to Pacific Central America, found north of Chiapas, Mexico. This could be due to northern expansion of this unique genotype as sea surface temperatures ameliorated following the last glacial maximum. Our data do not support the previous proposition of low diversity in the east central Pacific and suggest that much of the Pacific Central America diversity is from before the closure of the Isthmus of Panama.  相似文献   

16.
Several studies have reported glacial refugia and migration pathways for different pine species in the Iberian Peninsula, all of them based on a single‐species approach. In this paper, chloroplast microsatellites (cpSSRs) are used to compare population genetic structure and diversity estimates for interspecific pairs of populations located along a cline from southwestern (latitude 36°32′ N, longitude 5°17′ W) to northeastern Spain (latitude 42°14′ N, longitude 2°47′ E) in two widely distributed Mediterranean pines, Pinus halepensis Mill. and Pinus pinaster Ait. Some cpSSRs were shared between species, facilitating comparison of levels of gene diversity at the species level and inferences about within and among species differentiation. P. pinaster showed a much higher number of variants (29) and haplotypes (69) than P. halepensis (20 and 21, respectively). Moreover, genetic diversity estimates for interspecific pairs of populations along the cline were negatively correlated. Three main causes may explain the differences between species in the present‐day distribution of genetic diversity: (1) the distribution of genetic variability before the Quaternary glaciations, with an earlier presence of P. pinaster in the Iberian Peninsula and a late spread of P. halepensis from eastern and central Europe, (2) the location of the Holocene glacial refugia and the migration pathways from these refugia to the present‐day range (from northeast to southwest in P. halepensis and from southwest to northeast and northwest in P. pinaster) and (3) the interactions between species during the postglacial spread.  相似文献   

17.
A new species of Araceae, Rhodospatha arborescens, was found in two preservation areas in Minas Gerais state, Brazil, Caratinga Biological Station and Rio Doce State Park, both located in a semideciduous seasonal forest (Interior Atlantic Rainforest). The new species is helophytic and arborescent. It is described, illustrated, and compared with Rhodospatha species that occur in the Atlantic Rainforest, using a dichotomous key. Information is also presented on the geographic distribution, ecology, and phenology these species.  相似文献   

18.
Aim Deep‐sea hydrothermal vents are unstable habitats that are both spatially and temporally fragmented. In vent species, a ‘short‐term insurance’ hypothesis would lead us to expect mostly self‐recruitment, limiting the loss of larvae in the deep ocean or water column and increasing genetic differentiation over the time elapsed since colonization. Alternatively, a ‘long‐term insurance’ hypothesis would support the prediction of selection for large‐scale dispersal, to ensure long‐term persistence in these ephemeral habitats. The main goal of this study was to infer the spatial and temporal distribution of genetic diversity of the shrimp Rimicaris exoculata, which forms high‐density local populations on hydrothermal vents along the Mid‐Atlantic ridge. Location Deep‐sea hydrothermal vents along the Mid‐Atlantic Ridge. Methods We used sequences of mitochondrial cytochrome c oxidase subunit I (COI, 710 bp) to assess the spatio‐temporal distribution of genetic diversity across five hydrothermal fields from 36° N to 4° S. Results In contrast to previous results from pioneer studies, very high haplotype diversity was observed in vents across the entire region (i.e. 0.69–0.82), indicating current large effective population size and low drift. The star‐like shape of the network of haplotypes, the lack of spatial genetic structure and the significance of tests reflecting demographic effects, together with the fitting of a population expansion model, all support a recent population expansion. Main conclusions Our results suggest a very recent common history of R. exoculata populations/demes along the Mid‐Atlantic Ridge, derived after a common bottleneck or founder event and followed by a concomitant demographic expansion. This study therefore suggests a large effective population size and/or high dispersal capacity, as well as a possible recent (re)colonization of Mid‐Atlantic hydrothermal vents by R. exoculata.  相似文献   

19.
Three new species of Eupatorieae (Asteraceae) were collected in the “campos rupestres” of the Cadeia do Espinha?o, Minas Gerais state, Brazil, in the Itacolomi State Park, located between the cities of Ouro Preto and Mariana, Minas Gerais, Brazil, during a floristic survey focusing on Compositae in this area. Eupatorium semiamplexifolium, Mikania badiniana, and Stevia alexii are described and illustrated.  相似文献   

20.
Silva FA 《PloS one》2011,6(11):e27790
A new species of the genus Scybalocanthon Martínez 1948, Scybalocanthon korasakiaesp. nov., from Atlantic forest ecosystem, state of Minas Gerais, Brazil is described based on external and genital morphology.  相似文献   

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