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1.
Am J Bot ; 102(3): 423-38, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25784476

RESUMO

UNLABELLED: • PREMISE OF THE STUDY: Recent molecular studies provide a phylogenetic framework and some dated nodes for the monocot genus Smilax. The Caribbean Havanensis group of Smilax is part of a well-supported "New World clade" with a few disjunct taxa in the Old World. Although the fossil record of the genus is rich, it has been difficult to assign fossil taxa to extant groups based on their preserved morphological characters.• METHODS: Leaf fossils from Europe and Asia Minor were studied comparatively and put into a phylogenetic and biogeographic context using a molecular phylogeny of the genus.• KEY RESULTS: Fossils from the early Miocene of Anatolia represent a new species of Smilax with systematic affinities with the Havanensis group. The leaf type encountered in the fossil species is exclusively found in species of the Havanensis group among all modern Smilax. Scattered fossils of this type from the Miocene of Greece and Austria, previously referred to Quercus (Fagaceae), Ilex (Aquifoliaceae), and Mahonia (Berberidaceae) also belong to the new species.• CONCLUSIONS: The new Smilax provides first fossil evidence of the Havanensis group and proves that this group had a western Eurasian distribution during the Miocene. The age of the fossils is in good agreement with the (molecular-based) purported split between the Havanensis and Hispida groups within Smilax. The Miocene Smilax provides evidence that all four subclades within the "New World clade" had a disjunct intercontinental distribution during parts of the Neogene involving trans-Atlantic crossings (via floating islands or the North Atlantic land bridge) and the Beringia land bridge.


Assuntos
Evolução Biológica , Fósseis , Dispersão Vegetal , Smilax/classificação , Europa (Continente) , Filogenia , Smilax/anatomia & histologia , Turquia
2.
Rev Biol Trop ; 60(3): 1137-48, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23025085

RESUMO

Smilax L. in Brazil is represented by 32 taxa and it is a taxonomically difficult genus because the plants are dioecious and show wide phenotypic variation. The analysis and use of leaf anatomy characters is recognized as a frequently successful taxonomic method to distinguish between individual taxon, when floral material is absent or minute differences in flowers and foliage exist such as in Smilax. The aim of this study was to characterize the anatomical features of the aerial organs in Smilax syphilitica collected from the Atlantic Rainforest, in Santa Teresa-ES and the Smilax aff. syphilitica from the Amazon Rainforest, in Manaus, Brazil. For this, a total of three samples of Smilax were collected per site. Sample leaves and stems were fixed with FAA 50, embedded in historesin, sectioned on a rotary microtome, stained and mounted in synthetic resin. Additionally, histochemical tests were performed and cuticle ornamentation was analyzed with standard scanning electron microscopy. S. syphilitica and S. aff. syphilitica differed in cuticle ornamentation, epidermal cell arrangement and wall thickness, stomata type and orientation, calcium oxalate crystal type, and position of stem thorns. Leaf blades of S. syphilitica from the Amazon Rainforest have a network of rounded ridges on both sides, while in S. aff. syphilitica, these ridges are parallel and the spaces between them are filled with numerous membranous platelets. Viewed from the front, the epidermal cells of S. syphilitica have sinuous walls (even more pronounced in samples from the Amazon); while in S. aff. syphilitica, these cells are also sinuous but elongated in the cross-section of the blade and arranged in parallel. Stomata of S. syphilitica are paracytic, whereas in S. aff. syphilitica, are both paracytic and anisocytic, and their polar axes are directed towards the mid-vein. Calcium oxalate crystals in S. syphilitica are prisms, whereas in S. aff. syphilitica, crystal sand. Thorns occur in nodes and internodes in S. syphilitica but only in internodes in S. af. syphilitica. These features have proven to be of diagnostic value and may support a separation into two species, but future studies are needed to confirm that S. aff. syphilitica is indeed a new taxon.


Assuntos
Epiderme Vegetal/ultraestrutura , Folhas de Planta/ultraestrutura , Smilax/classificação , Microscopia Eletrônica de Varredura , Folhas de Planta/anatomia & histologia , Smilax/anatomia & histologia , Smilax/ultraestrutura
3.
Rev. biol. trop ; 60(3): 1137-1148, Sept. 2012. ilus, tab
Artigo em Inglês | LILACS | ID: lil-659575

RESUMO

Smilax L. in Brazil is represented by 32 taxa and it is a taxonomically difficult genus because the plants are dioecious and show wide phenotypic variation. The analysis and use of leaf anatomy characters is recognized as a frequently successful taxonomic method to distinguish between individual taxon, when floral material is absent or minute differences in flowers and foliage exist such as in Smilax. The aim of this study was to characterize the anatomical features of the aerial organs in Smilax syphilitica collected from the Atlantic Rainforest, in Santa Teresa-ES and the Smilax aff. syphilitica from the Amazon Rainforest, in Manaus, Brazil. For this, a total of three samples of Smilax were collected per site. Sample leaves and stems were fixed with FAA 50, embedded in historesin, sectioned on a rotary microtome, stained and mounted in synthetic resin. Additionally, histochemical tests were performed and cuticle ornamentation was analyzed with standard scanning electron microscopy. S. syphilitica and S. aff. syphilitica differed in cuticle ornamentation, epidermal cell arrangement and wall thickness, stomata type and orientation, calcium oxalate crystal type, and position of stem thorns. Leaf blades of S. syphilitica from the Amazon Rainforest have a network of rounded ridges on both sides, while in S. aff. syphilitica, these ridges are parallel and the spaces between them are filled with numerous membranous platelets. Viewed from the front, the epidermal cells of S. syphilitica have sinuous walls (even more pronounced in samples from the Amazon); while in S. aff. syphilitica, these cells are also sinuous but elongated in the cross-section of the blade and arranged in parallel. Stomata of S. syphilitica are paracytic, whereas in S. aff. syphilitica, are both paracytic and anisocytic, and their polar axes are directed towards the mid-vein. Calcium oxalate crystals in S. syphilitica are prisms, whereas in S. aff. syphilitica, crystal sand. Thorns occur in nodes and internodes in S. syphilitica but only in internodes in S. aff. syphilitica. These features have proven to be of diagnostic value and may support a separation into two species, but future studies are needed to confirm that S. aff. syphilitica is indeed a new taxon.


Smilax L. en Brasil está representado por 32 táxones y es un género difícil en lo que respecta a su taxonomía porque las plantas son diocas y presentan mucha variación fenotípica. El análisis y uso de los caracteres anatómicos de la hoja es reconocido frecuentemente como un exitoso método taxonómico para distinguir entre los táxones individuales cuando las flores están ausentes o hay diminutas diferencias. El objetivo de este estudio fue caracterizar los rasgos anatómicos de los órganos aéreos en Smilax syphilitica recolectados en el Bosque Atlántico en Santa Teresa- ES y de Smilax aff. syphilitica del Amazonas, Manaus, Brasil. Un total de tres muestras fueron recolectadas por sitio. Las muestras fueron fijadas en FAA 50, sumergidas en historesina, seccionadas en un micrótomo rotatorio, teñidas y montadas en resina sintética. Se hicieron pruebas histoquímicas y la ornamentación de la cutícula fue analizada con microscopía electrónica de barrido estándar. S. syphilitica y difirieron en la ornamentación de la cutícula, la disposición de células epidérmicas y el grosor de la pared, tipo y orientación de estomas, tipo de cristal de oxalato de calcio y la posición de las espinas del tallo. Estas características han probado ser de valor diagnóstico y pueden apoyar la separación de dos especies, pero se necesitan futuros estudios para confirmar que S. S. aff. syphiliticaaff. syphilitica es un nuevo taxon.


Assuntos
Epiderme Vegetal/ultraestrutura , Folhas de Planta/ultraestrutura , Smilax/classificação , Microscopia Eletrônica de Varredura , Folhas de Planta/anatomia & histologia , Smilax/anatomia & histologia , Smilax/ultraestrutura
4.
Mol Phylogenet Evol ; 64(3): 545-62, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22643288

RESUMO

The complete nucleotide sequence of the chloroplast genome (cpDNA) of Smilax china L. (Smilacaceae) is reported. It is the first complete cp genome sequence in Liliales. Genomic analyses were conducted to examine the rate and pattern of cpDNA genome evolution in Smilax relative to other major lineages of monocots. The cpDNA genomic sequences were combined with those available for Lilium to evaluate the phylogenetic position of Liliales and to investigate the influence of taxon sampling, gene sampling, gene function, natural selection, and substitution rate on phylogenetic inference in monocots. Phylogenetic analyses using sequence data of gene groups partitioned according to gene function, selection force, and total substitution rate demonstrated evident impacts of these factors on phylogenetic inference of monocots and the placement of Liliales, suggesting potential evolutionary convergence or adaptation of some cpDNA genes in monocots. Our study also demonstrated that reduced taxon sampling reduced the bootstrap support for the placement of Liliales in the cpDNA phylogenomic analysis. Analyses of sequences of 77 protein genes with some missing data and sequences of 81 genes (all protein genes plus the rRNA genes) support a sister relationship of Liliales to the commelinids-Asparagales clade, consistent with the APG III system. Analyses of 63 cpDNA protein genes for 32 taxa with few missing data, however, support a sister relationship of Liliales (represented by Smilax and Lilium) to Dioscoreales-Pandanales. Topology tests indicated that these two alignments do not significantly differ given any of these three cpDNA genomic sequence data sets. Furthermore, we found no saturation effect of the data, suggesting that the cpDNA genomic sequence data used in the study are appropriate for monocot phylogenetic study and long-branch attraction is unlikely to be the cause to explain the result of two well-supported, conflict placements of Liliales. Further analyses using sufficient nuclear data remain necessary to evaluate these two phylogenetic hypotheses regarding the position of Liliales and to address the causes of signal conflict among genes and partitions.


Assuntos
Genoma de Cloroplastos , Filogenia , Smilax/genética , Teorema de Bayes , DNA de Cloroplastos/genética , DNA de Plantas/genética , Biblioteca Gênica , Genoma de Planta , Análise de Sequência de DNA , Smilax/classificação
5.
Rev Biol Trop ; 60(1): 495-504, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22458242

RESUMO

Species of Smilax, also known as greenbrier, are widely distributed in Brazil and their commercial trades are carried out by the extractivism of native species. We the aim to provide information about the germination and development of seedlings in four Smilax species, different experiments were developed under controlled conditions. We evaluated two germination treatments: temperature (30 degrees C and 20-30 degrees C) and light (presence/ absence), and for few cases the tetrazolium treatment was applied. A different treatment response was observed among the studied species. Light had a significant influence in S. brasiliensis, with the highest germination rates at 20-30 degrees C in dark conditions. S. campestris showed significant differences among temperature treatments, but not to light; while S. cissoides showed high germination rates (66-78%), independently of treatment. However, S. polyantha had low germination rates (19-24%). After one year, the expanded leaves showed different characteristics among the studied species. Leaves of S. brasiliensis were ovate, coriaceous, three main veins and prickle-like structures only on the midrib on abaxial face. S. campestris leaves were oblong, coriaceous and prickle-like structures were located at the leaf midrib and margin. S. cissoides had ovate-elliptic, membranaceous leaves, with three main veins with prickle-like structures on the abaxial face. S. polyantha leaves showed ovate-elliptic, coriaceous leaves, with three main veins, translucent secondary veins and no prickle-like structures. A seedling identification key was elaborated based on morphological characteristics.


Assuntos
Germinação/fisiologia , Plântula/crescimento & desenvolvimento , Smilax/crescimento & desenvolvimento , Luz , Plântula/anatomia & histologia , Smilax/anatomia & histologia , Smilax/classificação , Temperatura
6.
Rev. biol. trop ; 60(1): 495-504, Mar. 2012. ilus, graf, tab
Artigo em Inglês | LILACS | ID: lil-657796

RESUMO

Species of Smilax, also known as greenbrier, are widely distributed in Brazil and their commercial trades are carried out by the extractivism of native species. We the aim to provide information about the germination and development of seedlings in four Smilax species, different experiments were developed under controlled conditions. We evaluated two germination treatments: temperature (30ºC and 20-30ºC) and light (presence/ absence), and for few cases the tetrazolium treatment was applied. A different treatment response was observed among the studied species. Light had a significant influence in S. brasiliensis, with the highest germination rates at 20-30ºC in dark conditions. S. campestris showed significant differences among temperature treatments, but not to light; while S. cissoides showed high germination rates (66-78%), independently of treatment. However, S. polyantha had low germination rates (19-24%). After one year, the expanded leaves showed different characteristics among the studied species. Leaves of S. brasiliensis were ovate, coriaceous, three main veins and prickle-like structures only on the midrib on abaxial face. S. campestris leaves were oblong, coriaceous and prickle-like structures were located at the leaf midrib and margin. S. cissoides had ovate-elliptic, membranaceous leaves, with three main veins with prickle-like structures on the abaxial face. S. polyantha leaves showed ovateelliptic, coriaceous leaves, with three main veins, translucent secondary veins and no prickle-like structures. A seedling identification key was elaborated based on morphological characteristics.


Assuntos
Germinação/fisiologia , Plântula/crescimento & desenvolvimento , Smilax/crescimento & desenvolvimento , Luz , Plântula/anatomia & histologia , Smilax/anatomia & histologia , Smilax/classificação , Temperatura
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