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‣ Isolamento de genes de resistência a Phytophthora cinnamoni e definição de um protocolo de transformação genética em Castanea sativa

Santos, Carmen Sofia Pedro dos, 1987-
Fonte: Universidade de Lisboa Publicador: Universidade de Lisboa
Tipo: Dissertação de Mestrado
Publicado em //2010 Português
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Tese de mestrado. Biologia (Biologia Celular e Biotecnologia). Universidade de Lisboa, Faculdade de Ciências, 2010; Castanea sativa pertence à família Fagaceae, tem um importante papel na ecologia, alimentação e economia. C. sativa sofre de uma doença severa, denominada por doença da tinta, causada maioritariamente pelo agente patogénico Phytophthora cinnamomi. A transformação genética surge como uma ferramenta poderosa para o melhoramento de plantas lenhosas como as espécies de castanheiro. No entanto, para obter uma transformação efectiva é necessário estabelecer um bom protocolo de regeneração. Existe também necessidade de conhecimento dos genes envolvidos na tolerância/sensibilidade. De modo a obter um sistema de regeneração eficiente em C. sativa, testaram-se três sistemas diferentes: embriogénese somática, indução de nódulos organogénicos e indução de regeneração directa de rebentos. A indução de regeneração directa teve um resultado positivo, levando à obtenção de regeneração de rebentos em cerca de 30% e 10% dos hipocótilos e dos epicótilos, respectivamente. Seguiu-se a construção do vector de transformação com um gene exógeno de óxido de aleno ciclase, relacionado com a resistência de C. sativa a P. cinnamomi...

‣ Biogeography, host specificity, and molecular phylogeny of the basidiomycetous yeast phaffia rhodozyma and its sexual form, xanthophyllomyces dendrorhous

Sampaio, José Paulo; Libkind, Diego; Ruffini, Alejandra; Alves, Leonor; Broock, Maria van
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /02/2007 Português
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Applied and Environmental Microbiology, Vol. 73, No.4; Phaffia rhodozyma (sexual form, Xanthophyllomyces dendrorhous) is a basidiomycetous yeast that has been found in tree exudates in the Northern Hemisphere at high altitudes and latitudes. This yeast produces astaxanthin, a carotenoid pigment with biotechnological importance because it is used in aquaculture for fish pigmentation. We isolated X. dendrorhous from the Southern Hemisphere (Patagonia, Argentina), where it was associated with fruiting bodies of Cyttaria hariotii, an ascomycetous parasite of Nothofagus trees. We compared internal transcribed spacer (ITS)-based phylogenies of P. rhodozyma and its tree host (Betulaceae, Corneaceae, Fagaceae, and Nothofagaceae) and found them to be generally concordant, suggesting that different yeast lineages colonize different trees and providing an explanation for the phylogenetic distance observed between the type strains of P. rhodozyma and X. dendrorhous. We hypothesize that the association of Xanthophyllomyces with Cyttaria derives from a previous association of the yeast with Nothofagus, and the sister relationship between Nothofagaceae and Betulaceae plus Fagaceae correlates with the phylogeny of X. dendrorhous strains originating from these three plant families. The two most basal strains of X. dendrorhous are those isolated from Cornus...

‣ Comparison of Quantitative Trait Loci for Adaptive Traits Between Oak and Chestnut Based on an Expressed Sequence Tag Consensus Map

Casasoli, Manuela; Derory, Jeremy; Morera-Dutrey, Caroline; Brendel, Oliver; Porth, Ilga; Guehl, Jean-Marc; Villani, Fiorella; Kremer, Antoine
Fonte: Copyright © 2006 by the Genetics Society of America Publicador: Copyright © 2006 by the Genetics Society of America
Tipo: Artigo de Revista Científica
Publicado em /01/2006 Português
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A comparative genetic and QTL mapping was performed between Quercus robur L. and Castanea sativa Mill., two major forest tree species belonging to the Fagaceae family. Oak EST-derived markers (STSs) were used to align the 12 linkage groups of the two species. Fifty-one and 45 STSs were mapped in oak and chestnut, respectively. These STSs, added to SSR markers previously mapped in both species, provided a total number of 55 orthologous molecular markers for comparative mapping within the Fagaceae family. Homeologous genomic regions identified between oak and chestnut allowed us to compare QTL positions for three important adaptive traits. Colocation of the QTL controlling the timing of bud burst was significant between the two species. However, conservation of QTL for height growth was not supported by statistical tests. No QTL for carbon isotope discrimination was conserved between the two species. Putative candidate genes for bud burst can be identified on the basis of colocations between EST-derived markers and QTL.

‣ Biogeography, Host Specificity, and Molecular Phylogeny of the Basidiomycetous Yeast Phaffia rhodozyma and Its Sexual Form, Xanthophyllomyces dendrorhous▿

Libkind, Diego; Ruffini, Alejandra; van Broock, Maria; Alves, Leonor; Sampaio, José Paulo
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Português
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Phaffia rhodozyma (sexual form, Xanthophyllomyces dendrorhous) is a basidiomycetous yeast that has been found in tree exudates in the Northern Hemisphere at high altitudes and latitudes. This yeast produces astaxanthin, a carotenoid pigment with biotechnological importance because it is used in aquaculture for fish pigmentation. We isolated X. dendrorhous from the Southern Hemisphere (Patagonia, Argentina), where it was associated with fruiting bodies of Cyttaria hariotii, an ascomycetous parasite of Nothofagus trees. We compared internal transcribed spacer (ITS)-based phylogenies of P. rhodozyma and its tree host (Betulaceae, Corneaceae, Fagaceae, and Nothofagaceae) and found them to be generally concordant, suggesting that different yeast lineages colonize different trees and providing an explanation for the phylogenetic distance observed between the type strains of P. rhodozyma and X. dendrorhous. We hypothesize that the association of Xanthophyllomyces with Cyttaria derives from a previous association of the yeast with Nothofagus, and the sister relationship between Nothofagaceae and Betulaceae plus Fagaceae correlates with the phylogeny of X. dendrorhous strains originating from these three plant families. The two most basal strains of X. dendrorhous are those isolated from Cornus...

‣ Principles of visual key construction―with a visual identification key to the Fagaceae of the southeastern United States

Kirchoff, Bruce K.; Leggett, Roxanne; Her, Va; Moua, Chue; Morrison, Jessica; Poole, Chamika
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
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We present the first visual, as opposed to illustrated, keys to a group of taxa. The creation of four visual keys to the Fagaceae of the southeastern United States are described, one for each of the following characteristics: leaves, buds, fruits, bark.

‣ Complete Plastid Genome Sequences of Three Rosids (Castanea, Prunus, Theobroma): Evidence for At Least Two Independent Transfers of rpl22 to the Nucleus

Jansen, Robert K.; Saski, Christopher; Lee, Seung-Bum; Hansen, Anne K.; Daniell, Henry
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
Português
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Functional gene transfer from the plastid to the nucleus is rare among land plants despite evidence that DNA transfer to the nucleus is relatively frequent. During the course of sequencing plastid genomes from representative species from three rosid genera (Castanea, Prunus, Theobroma) and ongoing projects focusing on the Fagaceae and Passifloraceae, we identified putative losses of rpl22 in these two angiosperm families. We further characterized rpl22 from three species of Passiflora and one species of Quercus and identified sequences that likely represent pseudogenes. In Castanea and Quercus, both members of the Fagaceae, we identified a nuclear copy of rpl22, which consisted of two exons separated by an intron. Exon 1 encodes a transit peptide that likely targets the protein product back to the plastid and exon 2 encodes rpl22. We performed phylogenetic analyses of 97 taxa, including 93 angiosperms and four gymnosperm outgroups using alignments of 81 plastid genes to examine the phylogenetic distribution of rpl22 loss and transfer to the nucleus. Our results indicate that within rosids there have been independent transfers of rpl22 to the nucleus in Fabaceae and Fagaceae and a putative third transfer in Passiflora. The high level of sequence divergence between the transit peptides in Fabaceae and Fagaceae strongly suggest that these represent independent transfers. Furthermore...

‣ Species Differentiation of Chinese Mollitrichosiphum (Aphididae: Greenideinae) Driven by Geographical Isolation and Host Plant Acquirement

Zhang, Ruiling; Huang, Xiaolei; Jiang, Liyun; Lei, Fumin; Qiao, Gexia
Fonte: Molecular Diversity Preservation International (MDPI) Publicador: Molecular Diversity Preservation International (MDPI)
Tipo: Artigo de Revista Científica
Publicado em 21/08/2012 Português
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The impact of both the uplift of the Qinghai-Tibetan Plateau (QTP) and the separation of the Taiwan and Hainan Islands on the evolution of the fauna and flora in adjacent regions has been a topic of considerable interest. Mollitrichosiphum is a polyphagous insect group with a wide range of host plants (14 families) and distributions restricted to Southeast Asia. Based on the mitochondrial Cytochrome C Oxidase Subunit I (COI) and Cytochrome b (Cytb) genes, the nuclear elongation factor-1α (EF-1α) gene, and the detailed distribution and host plant data, we investigated the species differentiation modes of the Chinese Mollitrichosiphum species. Phylogenetic analyses supported the monophyly of Mollitrichosiphum. The divergence time of Mollitrichosiphum tenuicorpus (c. 11.0 mya (million years ago)), Mollitrichosiphum nandii and Mollitrichosiphum montanum (c. 10.6 mya) was within the time frame of the uplift of the QTP. Additionally, basal species mainly fed on Fagaceae, while species that fed on multiple plants diverged considerably later. Ancestral state reconstruction suggests that Fagaceae may be the first acquired host, and the acquisition of new hosts and the expansion of host range may have promoted species differentiation within this genus. Overall...

‣ Genetic Differentiation and Genetic Diversity of Castanopsis (Fagaceae), the Dominant Tree Species in Japanese Broadleaved Evergreen Forests, Revealed by Analysis of EST-Associated Microsatellites

Aoki, Kyoko; Ueno, Saneyoshi; Kamijo, Takashi; Setoguchi, Hiroaki; Murakami, Noriaki; Kato, Makoto; Tsumura, Yoshihiko
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 30/01/2014 Português
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The broadleaved evergreen forests of the East Asian warm temperate zone are characterised by their high biodiversity and endemism, and there is therefore a need to extend our understanding of its genetic diversity and phylogeographic patterns. Castanopsis (Fagaceae) is one of the dominant tree species in the broadleaved evergreen forests of Japan. In this study we investigate the genetic diversity, genetic structure and leaf epidermal morphology of 63 natural populations of C. sieboldii and C. cuspidata, using 32 Expressed Sequence Tag associated microsatellites. The overall genetic differentiation between populations was low (GST = 0.069 in C. sieboldii and GST = 0.057 in C. cuspidata). Neighbor-joining tree and Bayesian clustering analyses revealed that the populations of C. sieboldii and C. cuspidata were genetically clearly differentiated, a result which is consistent with the morphology of their epidermal cell layers. This suggests that C. sieboldii and C. cuspidata should be treated as independent species, although intermediate morphologies are often observed, especially at sites where the two species coexist. The higher level of genetic diversity observed in the Kyushu region (for both species) and the Ryukyu Islands (for C. sieboldii) is consistent with the available fossil pollen data for Castanopsis-type broadleaved evergreen trees during the Last Glacial Maximum and suggests the existence of refugia for Castanopsis forests in southern Japan. Within the C. sieboldii populations...

‣ Molecular Organization of the 25S–18S rDNA IGS of Fagus sylvatica and Quercus suber: A Comparative Analysis

Inácio, Vera; Rocheta, Margarida; Morais-Cecílio, Leonor
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 03/06/2014 Português
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The 35S ribosomal DNA (rDNA) units, repeated in tandem at one or more chromosomal loci, are separated by an intergenic spacer (IGS) containing functional elements involved in the regulation of transcription of downstream rRNA genes. In the present work, we have compared the IGS molecular organizations in two divergent species of Fagaceae, Fagus sylvatica and Quercus suber, aiming to comprehend the evolution of the IGS sequences within the family. Self- and cross-hybridization FISH was done on representative species of the Fagaceae. The IGS length variability and the methylation level of 18 and 25S rRNA genes were assessed in representatives of three genera of this family: Fagus, Quercus and Castanea. The intergenic spacers in Beech and Cork Oak showed similar overall organizations comprising putative functional elements needed for rRNA gene activity and containing a non-transcribed spacer (NTS), a promoter region, and a 5′-external transcribed spacer. In the NTS: the sub-repeats structure in Beech is more organized than in Cork Oak, sharing some short motifs which results in the lowest sequence similarity of the entire IGS; the AT-rich region differed in both spacers by a GC-rich block inserted in Cork Oak. The 5′-ETS is the region with the higher similarity...

‣ Taxonomic and ecological discrimination of Fagaceae species based on internal transcribed spacer polymerase chain reaction–restriction fragment length polymorphism

Coutinho, João Paulo; Carvalho, Ana; Lima-Brito, José
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
Publicado em 14/01/2015 Português
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In 30 Fagaceae individuals from the Castanea, Fagus and Quercus genera, the internal transcribed spacer region (ITS) of the ribosomal DNA (rDNA) was amplified and digested with four restriction enzymes (HaeIII, HpaII, Sau96I, and TaqI), producing ITS PCR-RFLP markers. This technique allowed the discrimination of the Fagaceae species according to genus, infrageneric group and ecological area. This study constitutes the first application of the alternative co-dominant marker system ITS PCR-RFLP in Fagaceae species and proved to be highly suitable for taxonomic and ecological discrimination, constituting a useful molecular tool for taxonomists and forestry researchers.

‣ Fagaceae pollen from the early Cenozoic of West Greenland: revisiting Engler’s and Chaney’s Arcto-Tertiary hypotheses

Grímsson, Friðgeir; Zetter, Reinhard; Grimm, Guido W.; Pedersen, Gunver Krarup; Pedersen, Asger Ken; Denk, Thomas
Fonte: Springer Vienna Publicador: Springer Vienna
Tipo: Artigo de Revista Científica
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In this paper we document Fagaceae pollen from the Eocene of western Greenland. The pollen record suggests a remarkable diversity of the family in the early Cenozoic of Greenland. Extinct Fagaceae pollen types include Eotrigonobalanus, which extends at least back to the Paleocene, and two ancestral pollen types with affinities to the Eurasian Quercus Group Ilex and the western North American Quercus Group Protobalanus. In addition, modern lineages of Fagaceae are unambiguously represented by pollen of Fagus, Quercus Group Lobatae/Quercus, and three Castaneoideae pollen types. These findings corroborate earlier findings from Axel Heiberg Island that Fagaceae were a dominant element at high latitudes during the early Cenozoic. Comparison with coeval or older mid-latitude records of modern lineages of Fagaceae shows that modern lineages found in western Greenland and Axel Heiberg likely originated at lower latitudes. Further examples comprise (possibly) Acer, Aesculus, Alnus, Ulmus, and others. Thus, before fossils belonging to modern northern temperate lineages will have been recovered from older (early Eocene, Paleocene) strata from high latitudes, Engler’s hypothesis of an Arctic origin of the modern temperate woody flora of Eurasia...

‣ Oviposition Preference and Offspring Performance of Mechoris ursulus (Coleoptera: Attelabidae) in Cyclobalanopsis glaucoides (Fagales: Fagaceae) and Quercus franchetii (Fagales: Fagaceae) in Central Yunnan, China

Wang, Xu; Hu, Shao-Ji; Zhang, Zhi-Ying; Geng, Yu-Peng; Bai, Xue
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
Publicado em 19/03/2015 Português
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Mechoris ursulus (Roelofs) (Coleoptera: Attelabidae) is a pest weevil of Fagaceae oak trees in eastern Asia. The female has a distinct branch-cutting behavior in conjunction with oviposition in the acorns of its host plant. This study analyzed the factors influencing oviposition preference by carrying out continuous field surveys over the course of 2009–2010 and through laboratory rearing. The field survey showed that for both of the hosts, Cyclobalanopsis glaucoides Schottky (Fagales: Fagaceae) and Quercus franchetii Skan, M. ursulus preferred branches with fewer acorns and larger acorns on the same branch for oviposition. Laboratory rearing experiments showed offspring performance (i.e., survival rate and fresh weight of larvae) was significantly and positively correlated with acorn size. Preference for larger acorns could maximize the fitness of offspring by providing sufficient food source and space.

‣ Epigenetic marks in the mature pollen of Quercus suber L. (Fagaceae)

Ribeiro, Teresa; Viegas, Wanda; Morais-Cecílio, Leonor
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
Publicado em //2009 Português
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We have analysed the distribution of epigenetic marks for histone modifications at lysine residues H3 and H4, and DNA methylation, in the nuclei of mature pollen cells of the Angiosperm tree Quercus suber; a monoecious wind pollinated species with a protandrous system, and a long post-pollination period. The ultrasonic treatment developed for the isolation of pollen nuclei proved to be a fast and reliable method, preventing the interference of cell wall autofluorescence in the in situ immunolabelling assays. In contrast with previous studies on herbaceous species with short progamic phases, our results are consistent with a high level of silent (5-mC and H3K9me2) epigenetic marks on chromatin of the generative nucleus, and the prevalence of active marks (H3K9me3 and H4Kac) in the vegetative nucleus. The findings are discussed in terms of the pollination/fertilization timing strategy adopted by this plant species

‣ Genetic diversity in Nothofagus alessandrii (Fagaceae), an endangered endemic tree species of the coastal maulino forest of central Chile

Cavieres, Lohengrin A.; Fuentes, Glenda; González, Fidelina; Ruiz, Eduardo; Torres Díaz, Cristian
Fonte: OXFORD UNIV PRESS Publicador: OXFORD UNIV PRESS
Tipo: Artículo de revista
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Background and Aims The endemic tree Nothofagus alessandrii (Fagaceae) has been historically restricted to the coastal range of Region VII of central Chile, and its forests have been increasingly destroyed and fragmented since the end of the 19th century. In this study, the patterns of within- and among-population genetic diversity in seven fragments of this endangered narrowly endemic tree were examined. Methods Allozyme electrophoresis of seven loci of N. alessandrii was used to estimate genetic diversity, genetic structure and gene flow. Key Results High levels of genetic diversity were found as shown by mean expected heterozygosity (11, = 0.182 +/- 0.034), percentage of polymorphic loci (P-p = 61 center dot 2 %), mean number of alleles per locus (A = 1 center dot 8) and mean number of alleles per polymorphic locus (A(p) = 2 center dot 3). Genetic differentiation was also high (GST = 0.257 and N-m = 0 center dot 7). These values are high compared with more widespread congeneric species. Conclusions Despite its endemic status and restricted geographical range N. alessandrii showed high levels of genetic diversity. The observed patterns of diversity are explained in part by historical processes and more recent human fragmentation.

‣ Protocol for micropropagation of Castanea sativa Mill.

Viéiztez, Ana M.; Sánchez Fernández, M.ª Concepción; García Nimo, M.ª Lourdes; Ballester, Antonio
Fonte: Springer Publicador: Springer
Tipo: Capítulo de libro Formato: 848267 bytes; application/pdf
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Final version of the chapter at: http://dx.doi.org/10.1007/978-1-4020-6352-7_28.; Since the 1970s, natural resources the world over have been progressively re-evaluated in accordance with the principles of sustainable agriculture. The European chestnut, Castanea sativa Mill., a hardwood species belonging to the family Fagaceae, has not been unaffected by this process. It is an important resource in many parts of the world because of its economic and environmental role in many agroforestry systems, and in Europe it has been gaining in value as a source of timber and nut production and due to the contribution of chestnut groves to the landscape (Bounous, 2005).; Like the American chestnut C. dentata, C. sativa has been plagued for more than a century by ink disease and chestnut blight, caused by the fungi Phytophthora cinnamomi and Cryphonectria parasitica, respectively. A great deal of research on chestnut focuses on the development of vegetative propagation systems capable of satisfying the demand for elite genotypes that provide both high-quality timber and/or nuts and resistance to these diseases. Since chestnut is a difficult-to-root species, grafting is the most frequent conventional propagation technique, although methods for layering and cutting have recently been improved and are widely used in nurseries to propagate ink-disease-resistant Euro-Japanese hybrids. However...

‣ Estudio cariológico de Quercus laurina Humb. & Bonpl.

Hernández-Vital,Carlos Rafael; Álvarez-Moctezuma,José Guadalupe; Zavala-Chávez,Fernando; Espinosa-Robles,Policarpo
Fonte: Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias Publicador: Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2009 Português
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Los encinos (Quercus spp., Fagaceae), en razón de su abundancia, son el grupo de latifoliadas más importante de las áreas templadas de México. A pesar de ello, han sido poco estudiadas desde el punto de vista cariológico. En este sentido, es escasa la información del género Quercus, que está basada en especies de Europa y Estados Unidos. En dichas investigaciones se reporta que el número básico cromosómico es 12 y el número cromosómico somático, 24. El objetivo de este trabajo fue realizar un análisis cariológico de Q. laurina para aplicarse en estudios taxonómicos. Se aislaron ápices radicales de plántulas recién emergidas, mismos que se conservaron en paradiclorobenceno (30g/L) y fijándose en solución Carnoy 6:1:1 (v:v:v). Se tiñó con acetocarmín. Se usó la técnica de aplastado con ácido acético. El análisis cromosómico se efectuó en un microscopio compuesto, observando las células mitóticas en metafase. Los resultados cariológicos de Q. laurina indican que es una especie diploide, con un número cromosómico básico x = 12, un complemento haploide de 37.2 μm, un índice centromérico de 40.83 μm y un índice de asimetría intracromosomal de 0.28 y un cariotipo de 18 cromosomas metacéntricos y seis submetacéntricos. La cariomorfología de Q. laurina es similar a la reportada para otras especies del género Quercus.

‣ Nuevas especies de Quercus (Fagaceae) en el Plioceno de Santa María Amajac, Hidalgo, México

Velasco-de León,María Patricia; Ortiz-Martínez,Erika Lourdes
Fonte: Instituto de Geología, UNAM Publicador: Instituto de Geología, UNAM
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2010 Português
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Se describen siete nuevas especies fósiles de la familia Fagaceae para México, utiliiando la arquitectura foliar: Quercus amajensis, Q. cevalli, Q. curvensis, Q. grandensis, Q. hidalgensis, Q. ovatus y Q. rugosus. Las impresiones de hojas fósiles fueron colectadas en las localidades de Sanctorum y Los Baños, Hidalgo, dentro de la Formación Atotonilco El Grande. El análisis fenético realiiado permite concluir que los caracteres importantes que definen a las nuevas especies son: recorrido de las venas terciarias, venación de quinto orden, forma y tamaño de areolas, presencia de venas intersecundarias y recorrido de la vena secundaria dentro del diente. Estos resultados apoyan la idea de la importancia del Cinturón Volcánico Transmexicano como área de especiación.

‣ The taxonomic status of the Mexican oak Quercus undata (Fagaceae, Quercus, Section Quercus)

Bacon,Jeffrey R.; Dávila-Aranda,Patricia Dolores; Spellenberg,Richard; González-Elizondo,M. Socorro
Fonte: Instituto de Biología Publicador: Instituto de Biología
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2011 Português
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Quercus undata Trel. (Fagaceae, Quercus, Section Quercus) has a complex taxonomic and nomenclatural history. Intensive sampling of oaks at the type locality of Q. undata Trel. in Durango, Mexico and evaluation of herbarium specimens and plants in the field indicate that Q. undata represents variation in Quercus chihuahuensis Trel. in white oak communities where introgressive hybridization among Q. chihuahuensis, Q. grisea Liebm., and a third white oak, Q. arizonica Sarg. made species identification difficult. Endlich's type specimen of Q. undata, as designated by Trelease, was apparently destroyed in bombing raids on Berlin during World War II, and we propose herein as lectotype the Trelease illustration of the type. An epitype is also designated in support of the lectotype, given that some features cannot be critically observed on the illustration. The long peduncles of the specimen illustrated by Trelease indicate a close relation to Q. chihuahuensis.

‣ La familia Fagaceae en el bosque mesófilo de montaña de México

Valencia-A.,Susana; Gual-Díaz,Martha
Fonte: Sociedad Botánica de México A.C. Publicador: Sociedad Botánica de México A.C.
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2014 Português
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El bosque mesófilo de montaña es uno de los tipos de vegetación más amenazados, donde la familia Fagaceae juega un papel ecológico clave, por lo que su conocimiento en esta comunidad es importante para su conservación. Con base en datos de herbario y de campo, de literatura y del Sistema de Información de los Bosques Mesófilos de Montaña en México, elaborado por la Comisión Nacional para el Conocimiento y Uso de la Biodiversidad, se presenta un análisis de la familia Fagaceae en el bosque mesófilo de montaña, con énfasis en las 13 regiones prioritarias propuestas por la Comisión Nacional para el Conocimiento y Uso de la Biodiversidad para la conservación del bosque mesófilo de montaña. Asimismo, se compiló la categoría de riesgo de las Fagaceae en este bosque. Los resultados muestran que en este ecosistema están presentes 47 especies de Fagaceae, 46 de Quercus (32 de la sección Lobatae y 14 de la sección Quercus) y una de Fagus; de ellas, 13 se consideran exclusivas o casi exclusivas de esta comunidad y endémicas de México. De las 13 regiones prioritarias, la región III (Huasteca Alta Hidalguense) resultó la de mayor diversidad con 26 especies, mientras que la región VII (Los Tuxtlas) es la menos diversa con sólo dos especies. El análisis de diversidad ß muestra un recambio de medio a alto que va de 0.41 a 1 entre las 13 regiones. Las regiones más similares en cuanto a especies de Fagaceae fueron la III (Huasteca Alta Hidalguense) y la V (Centro de Veracruz). Las especies de Fagaceae señaladas con alguna categoría de riesgo o amenaza son 41. Destacan ocho especies de Lobatae que se consideran críticamente amenazadas y cinco de Quercus en la misma categoría.

‣ Estructura y composición florística de dos comunidades con presencia de quercus (fagaceae) en el Estado de México

Rubio-Licona,Liliana E.; Romero-Rangel,Silvia; Rojas-Zenteno,E. Carlos
Fonte: Universidad Autónoma Chapingo, Coordinación de Revistas Institucionales Publicador: Universidad Autónoma Chapingo, Coordinación de Revistas Institucionales
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2011 Português
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En este trabajo se caracterizaron en términos de estructura, diversidad y composición florística, dos comunidades de Quercus del Estado de México. Se evaluaron la densidad y el área basal de los árboles del dosel, la cobertura del estrato arbustivo y se tomó registro de las especies herbáceas. Los atributos de la vegetación fueron empleados para calcular el valor de importancia relativa de las especies. El número de taxas y el valor de diversidad de las dos comunidades fueron similares. En la localidad de Cieneguillas de González, Temascaltepec, se encuentra un bosque mesófilo de montaña donde el encino de mayor importancia estructural es Quercus candicans; las otras especies de importancia fueron Clethra mexicana, Ternstroemia lineata, Pinus pseudostrobus y Pinus leiophylla. En la localidad de Llano del Huilo, Villa del Carbón, existe un bosque de encino-pino donde Quercus crassifolia posee el valor de importancia más alto, seguido por Pinus teocote, Quercus obtusata, Quercus candicans, Quercus crassipes y Arbutus xalapensis. El estrato arbustivo, aunque más diverso en el bosque mesófilo de montaña, tuvo mayor cobertura en el bosque de encino-pino.