RESUMO
BACKGROUND: Caryodaphnopsis, a group of tropical trees (ca. 20 spp.) in the family Lauraceae, has an amphi-Pacific disjunct distribution: ten species are distributed in Southeast Asia, while eight species are restricted to tropical rainforests in South America. Previously, phylogenetic analyses using two nuclear markers resolved the relationships among the five species from Latin America. However, the phylogenetic relationships between the species in Asia remain poorly known. RESULTS: Here, we first determined the complete mitochondrial genome (mitogenome), plastome, and the nuclear ribosomal cistron (nrDNA) sequences of C. henryi with lengths of 1,168,029 bp, 154,938 bp, and 6495 bp, respectively. We found 2233 repeats and 368 potential SSRs in the mitogenome of C. henryi and 50 homologous DNA fragments between its mitogenome and plastome. Gene synteny analysis revealed a mass of rearrangements in the mitogenomes of Magnolia biondii, Hernandia nymphaeifolia, and C. henryi and only six conserved clustered genes among them. In order to reconstruct relationships for the ten Caryodaphnopsis species in Asia, we created three datasets: one for the mitogenome (coding genes and ten intergenic regions), another for the plastome (whole genome), and the other for the nuclear ribosomal cistron. All of the 22 Caryodaphnopsis individuals were divided into four, five, and six different clades in the phylogenies based on mitogenome, plastome, and nrDNA datasets, respectively. CONCLUSIONS: The study showed phylogenetic conflicts within and between nuclear and organellar genome data of Caryodaphnopsis species. The sympatric Caryodaphnopsis species in Hekou and Malipo SW China may be related to the incomplete lineage sorting, chloroplast capture, and/or hybridization, which mixed the species as a complex in their evolutionary history.
Assuntos
Genoma Mitocondrial , Lauraceae , Filogenia , Lauraceae/genética , Lauraceae/classificação , Genoma de PlantaRESUMO
Abstract Essential oils from four Ocotea species collected in southern Brazil were evaluated for chemical composition using gas chromatography coupled with mass spectrometry. The primary compound identified in O. acutifolia essential oil was an unsaturated tetracyclic diterpene, phyllocladene (67.7%), followed by a sesquiterpene hydrocarbon, ß-selinene (18.0%). The sesquiterpene fraction was predominant in oils from two collections of O. puberula; ß-caryophyllene (25.2%) and globulol (22.6%) were the major compounds identified in collections 1 and 2, respectively. O. silvestris essential oil contained predominantly germacrene D and bicyclogermacrene. These compounds were also predominant in essential oil from O. indecora leaves collected from shady habitats. By contrast, essential oil extracted from O. indecora grown under direct sunlight contained mainly oxygenated sesquiterpenes, such as guaiol (30.2%), α-eudesmol (27.6%), and ß-eudesmol (12.7%). Chemotaxis assays showed that Ocotea essential oils had no significant inhibitory activity on leukocyte migration compared with a chemotactic stimulant (lipopolysaccharide from Escherichia coli). However, the oils exhibited antifungal activity against Candida parapsilosis, with a minimum inhibitory concentration of 500 µg/mL. To our knowledge, this is the first study to investigate the in vitro antifungal and antichemotactic activities of essential oils from Ocotea species native to southern Brazil
Assuntos
Óleos Voláteis/química , Ocotea/anatomia & histologia , Produtos Biológicos , Ecossistema , Lauraceae/classificação , Candida parapsilosis , Cromatografia Gasosa-Espectrometria de Massas/métodosRESUMO
Lauraceae species are widely represented in the Amazon, presenting a significant essential oil yield, large chemical variability, various biological applications, and high economic potential. Its taxonomic classification is difficult due to the accentuated morphological uniformity, even among taxa from a different genus. For this reason, the present work aimed to find chemical and molecular markers to discriminate Aniba species collected in the Pará State (Brazil). The chemical composition of the essential oils from Aniba canelilla, A. parviflora, A. rosaeodora, and A. terminalis were grouped by multivariate statistical analysis. The major compounds were rich in benzenoids and terpenoids such as 1-nitro-2-phenylethane (88.34-70.85%), linalool (15.2-75.3%), α-phellandrene (36.0-51.8%), and ß-phellandrene (11.6-25.6%). DNA barcodes were developed using the internal transcribed spacer (ITS) nuclear region, and the matK, psbA-trnH, rbcL, and ycf1 plastid regions. The markers psbA-trnH and ITS showed the best discrimination for the species, and the phylogenic analysis in the three- (rbcL + matK + trnH - psbA and rbcL + matK + ITS) and four-locus (rbcL + matK + trnH - psbA + ITS) combination formed clades with groups strongly supported by the Bayesian inference (BI) (PP:1.00) and maximum likelihood (ML) (BS ≥ 97%). Therefore, based on statistical multivariate and phylogenetic analysis, the results showed a significant correlation between volatile chemical classes and genetic characteristics of Aniba species.
Assuntos
Código de Barras de DNA Taxonômico/métodos , DNA de Plantas , Lauraceae , Óleos Voláteis/análise , Brasil , Lauraceae/química , Lauraceae/classificação , Filogenia , Especificidade da EspécieRESUMO
This study aimed to evaluate the anticholinesterase activities of extracts and fractions of Ocotea daphnifolia in vitro and characterize its constituents. The effects of hexane, ethyl acetate, and ethanolic extracts on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activity were determined with a spectrophotometry assay. All extracts inhibited cholinesterase activity, and the ethanolic extract (2 mg/mL) exhibited the highest inhibition of both enzymes (99.7% for BuChE and 82.4% for AChE). The ethanolic extract was fractionated by column chromatography resulting in 14 fractions that were also screened for their anticholinesterase effects. Fraction 9 (2 mg/mL) showed the highest activity, inhibiting AChE and BuChE by 71.8% and 90.2%, respectively. This fraction was analyzed by high-performance liquid chromatography high-resolution mass spectrometry which allowed the characterization of seven glycosylated flavonoids (containing kaempferol and quercetin nucleus) and one alkaloid (reticuline). In order to better understand the enzyme-inhibitor interaction of the reticuline toward cholinesterase, molecular modeling studies were performed. Reticuline targeted the catalytic activity site of the enzymes. Ocotea daphnifolia exhibits a dual cholinesterase inhibitory activity and displays the same pattern of intermolecular interactions as described in the literature. The alkaloid reticuline can be considered as an important bioactive constituent of this plant.
Assuntos
Técnicas In Vitro/instrumentação , Inibidores da Colinesterase/análise , Lauraceae/classificação , Ocotea/efeitos adversos , Simulação de Acoplamento Molecular/instrumentação , Plantas Medicinais/anatomia & histologia , Acetilcolinesterase/efeitos adversos , Espectrofotometria/instrumentação , Flavonoides , Butirilcolinesterase/efeitos adversos , AlcaloidesRESUMO
Intergeneric relationships of the Beilschmiedia group (Lauraceae) remain unresolved, hindering our understanding of their classification and evolutionary diversification. To remedy this, we sequenced and assembled complete plastid genomes (plastomes) from 25 species representing five genera spanning most major clades of Beilschmiedia and close relatives. Our inferred phylogeny is robust and includes two major clades. The first includes a monophyletic Endiandra nested within a paraphyletic Australasian Beilschmiedia group. The second includes (i) a subclade of African Beilschmiedia plus Malagasy Potameia, (ii) a subclade of Asian species including Syndiclis and Sinopora, (iii) the lone Neotropical species B. immersinervis, (iv) a subclade of core Asian Beilschmiedia, sister to the Neotropical species B. brenesii, and v) two Asian species including B. turbinata and B. glauca. The rampant non-monophyly of Beilschmiedia we identify necessitates a major taxonomic realignment of the genus, including but not limited to the mergers of Brassiodendron and Sinopora into the genera Endiandra and Syndiclis, respectively. Along these lines, the high degree of continental, clade-wide endemism we identify suggests that geographical distribution may be a good proxy for delineating taxa within this group. Our molecular divergence time estimates indicate that stem Beilschmiedia group members date to the Early Eocene (~50 Ma); their crown age dates to the Eocene-Oligocene boundary (~34 Ma). These findings contradict older estimates of the group and support mounting evidence that the origin and diversification of many pantropical angiosperm clades are not easily attributed to strict western Gondwanan vicariance. Finally, our study highlights the phylogenetic utility of plastomes in Lauraceace, and lays a solid foundation for future phylogenomic and biogeographic investigations within the family.
Assuntos
Genomas de Plastídeos , Lauraceae/classificação , Lauraceae/genética , Filogenia , Sequência de Bases , Calibragem , DNA Circular/genética , DNA de Plantas/genética , Fósseis , Repetições de Microssatélites/genética , Anotação de Sequência Molecular , Fatores de TempoRESUMO
To date, little is known about the evolution of plastid genomes (plastomes) in Lauraceae. As one of the top five largest families in tropical forests, the Lauraceae contain many species that are important ecologically and economically. Lauraceous species also provide wonderful materials to study the evolutionary trajectory in response to parasitism because they contain both nonparasitic and parasitic species. This study compared the plastomes of nine Lauraceous species, including the sole hemiparasitic and herbaceous genus Cassytha (laurel dodder; here represented by Cassytha filiformis). We found differential contractions of the canonical inverted repeat (IR), resulting in two IR types present in Lauraceae. These two IR types reinforce Cryptocaryeae and Neocinnamomum-Perseeae-Laureae as two separate clades. Our data reveal several traits unique to Cas. filiformis, including loss of IRs, loss or pseudogenization of 11 ndh and rpl23 genes, richness of repeats, and accelerated rates of nucleotide substitutions in protein-coding genes. Although Cas. filiformis is low in chlorophyll content, our analysis based on dN/dS ratios suggests that both its plastid house-keeping and photosynthetic genes are under strong selective constraints. Hence, we propose that short generation time and herbaceous lifestyle rather than reduced photosynthetic ability drive the accelerated rates of nucleotide substitutions in Cas. filiformis.
Assuntos
Evolução Molecular , Genomas de Plastídeos , Lauraceae/genética , Rearranjo Gênico , Sequências Repetidas Invertidas , Lauraceae/classificação , Filogenia , Proteínas de Plantas/genética , PseudogenesRESUMO
Machilus pauhoi Kanehira is an important timber species in China. A provenance trial was recently set up to evaluate the growth performance of trees from different localities, with the aim of designing seed transfer guidelines. Here, we tested twelve nuclear microsatellite markers derived from other species of the Lauraceae family and investigated population genetic structure in M. pauhoi. Both the number of observed alleles per locus (Na) and the polymorphic information content (PIC) significantly decreased against the latitude, but showed an insignificant decrease against the longitude. Heterozygosity (Ho) and gene diversity (h) exhibited a weak correlation with geographic location. Private alleles were present in multiple populations, and a moderate level of population genetic differentiation was detected (Gst = 0.1691). The joint pattern of genetic diversity (Na, PIC, Ho, and h) suggests that general northeastward dispersal led to the current distribution of M. pauhoi. Significant but weak effects of isolation-by-distance (IBD) occurred, implicating the mountain ranges as the major barrier to gene flow. Both STRUCTURE and hierarchical clustering analyses showed three distinct groups of populations related to the physical connectivity among mountain ranges. A priority in designing genetic conservation should be given to the populations at the southwest side of the species' distribution. This conservation strategy can also be combined with the pattern of adaptive genetic variation from the provenance trial for comprehensive genetic resource management of native M. pauhoi.
Assuntos
Lauraceae/classificação , Lauraceae/genética , Filogenia , Filogeografia , Alelos , China , Meio Ambiente , Variação Genética , Genética Populacional , Geografia , Repetições de Microssatélites , Polimorfismo Genético , Dinâmica PopulacionalRESUMO
Available plastomes of the Lauraceae show similar structure and varied size, but there has been no systematic comparison across the family. In order to understand the variation in plastome size and structure in the Lauraceae and related families of magnoliids, we here compare 47 plastomes, 15 newly sequenced, from 27 representative genera. We reveal that the two shortest plastomes are in the parasitic Lauraceae genus Cassytha, with lengths of 114,623 (C. filiformis) and 114,963 bp (C. capillaris), and that they have lost NADH dehydrogenase (ndh) genes in the large single-copy region and one entire copy of the inverted repeat (IR) region. The plastomes of the core Lauraceae group, with lengths from 150,749 bp (Nectandra angustifolia) to 152,739 bp (Actinodaphne trichocarpa), have lost trnI-CAU, rpl23, rpl2, a fragment of ycf2, and their intergenic regions in IRb region, whereas the plastomes of the basal Lauraceae group, with lengths from 157,577 bp (Eusideroxylon zwageri) to 158,530 bp (Beilschmiedia tungfangensis), have lost rpl2 in IRa region. The plastomes of Calycanthus (Calycanthaceae, Laurales) have lost rpl2 in IRb region, but the plastome of Caryodaphnopsis henryi (Lauraceae) remain intact, as do those of the nonLaurales magnoliid genera Piper, Liriodendron, and Magnolia. On the basis of our phylogenetic analysis and structural comparisons, different loss events occurred in different lineages of the Laurales, and fragment loss events in the IR regions have largely driven the contraction of the plastome in the Lauraceae. These results provide new insights into the evolution of the Lauraceae as well as the magnoliids as a whole.
Assuntos
Evolução Molecular , Genoma de Cloroplastos , Lauraceae/genética , Magnolia/genética , DNA Intergênico , Sequências Repetidas Invertidas , Lauraceae/classificação , Magnolia/classificação , NADH Desidrogenase/genética , Filogenia , Proteínas de Plantas/genética , Homologia de SequênciaRESUMO
Ocotea species present economic importance and biological activities attributed to their essential oils (EOs) and extracts. For this reason, various strategies have been developed for their conservation. The chemical compositions of the essential oils and matK DNA sequences of O. caudata, O. cujumary, and O. caniculata were subjected to comparison with data from O. floribunda, O. veraguensis, and O. whitei, previously reported. The multivariate analysis of chemical composition classified the EOs into two main clusters. Group I was characterized by the presence of α-pinene (9.8-22.5%) and ß-pinene (9.7-21.3%) and it includes O. caudata, O. whitei, and O. floribunda. In group II, the oils of O. cujumary and O. caniculata showed high similarity due amounts of ß-caryophyllene (22.2% and 18.9%, respectively). The EO of O. veraguensis, rich in p-cymene (19.8%), showed minor similarity among all samples. The oils displayed promising antimicrobial and cytotoxic activities against Escherichia coli (minimum inhibitory concentration (MIC) < 19.5 µg·mL-1) and MCF-7 cells (median inhibitory concentration (IC50) â 65.0 µg·mL-1), respectively. The analysis of matK gene displayed a good correlation with the main class of chemical compounds present in the EOs. However, the matK gene data did not show correlation with specific compounds.
Assuntos
Ocotea/química , Ocotea/genética , Terpenos/química , Compostos Orgânicos Voláteis/química , Monoterpenos Bicíclicos , Cimenos , Escherichia coli/efeitos dos fármacos , Humanos , Lauraceae/química , Lauraceae/classificação , Lauraceae/genética , Células MCF-7 , Monoterpenos/química , Ocotea/classificação , Filogenia , Compostos Orgânicos Voláteis/farmacologiaRESUMO
Lauraceae are an important component of tropical and subtropical forests and have major ecological and economic significance. Owing to lack of clear-cut morphological differences between genera and species, this family is an ideal case for testing the efficacy of DNA barcoding in the identification and discrimination of species and genera. In this study, we evaluated five widely recommended plant DNA barcode loci matK, rbcL, trnH-psbA, ITS2 and the entire ITS region for 409 individuals representing 133 species, 12 genera from China. We tested the ability of DNA barcoding to distinguish species and as an alternative tool for correcting species misidentification. We also used the rbcL+matK+trnH-psbA+ITS loci to investigate the phylogenetic relationships of the species examined. Among the gene regions and their combinations, ITS was the most efficient for identifying species (57.5%) and genera (70%). DNA barcoding also had a positive role for correcting species misidentification (10.8%). Furthermore, based on the results of the phylogenetic analyses, Chinese Lauraceae species formed three supported monophyletic clades, with the Cryptocarya group strongly supported (PP = 1.00, BS = 100%) and the clade including the Persea group, Laureae and Cinnamomum also receiving strong support (PP = 1.00, BS = 98%), whereas the Caryodaphnopsis-Neocinnamomum received only moderate support (PP = 1.00 and BS = 85%). This study indicates that molecular barcoding can assist in screening difficult to identify families like Lauraceae, detecting errors of species identification, as well as helping to reconstruct phylogenetic relationships. DNA barcoding can thus help with large-scale biodiversity inventories and rare species conservation by improving accuracy, as well as reducing time and costs associated with species identification.
Assuntos
Código de Barras de DNA Taxonômico , DNA de Plantas/genética , Lauraceae/classificação , Lauraceae/genética , China , Filogenia , Especificidade da EspécieRESUMO
The accurate identification of bay leaf in natural products commerce may often be confusing as the name is applied to several different species of aromatic plants. The true "bay leaf", also known as "bay laurel" or "sweet bay", is sourced from the tree Laurus nobilis, a native of the Mediterranean region. Nevertheless, the leaves of several other species including Cinnamomum tamala, Litsea glaucescens, Pimenta racemosa, Syzygium polyanthum, and Umbellularia californica are commonly substituted or mistaken for true bay leaves due to their similarity in the leaf morphology, aroma, and flavor. Substitute species are, however, often sold as "bay leaves". As such, the name "bay leaf" in literature and herbal commerce may refer to any of these botanicals. The odor and flavor of these leaves are, however, not the same as the true bay leaf, and for that reason they should not be used in cooking as a substitute for L. nobilis. Some of the bay leaf substitutes can also cause potential health problems. Therefore, the correct identification of the true bay leaf is important. The present work provides a detailed comparative study of the leaf morphological and anatomical features of L. nobilis and its common surrogates to allow for correct identification.
Assuntos
Lauraceae/classificação , Laurus/classificação , Myrtaceae/classificação , Cinnamomum/anatomia & histologia , Cinnamomum/classificação , Lauraceae/anatomia & histologia , Laurus/anatomia & histologia , Litsea/anatomia & histologia , Litsea/classificação , Myrtaceae/anatomia & histologia , Pimenta/anatomia & histologia , Pimenta/classificação , Folhas de Planta/anatomia & histologia , Folhas de Planta/classificação , Controle de Qualidade , Syzygium/anatomia & histologia , Syzygium/classificação , Árvores , Umbellularia/anatomia & histologia , Umbellularia/classificaçãoRESUMO
ABSTRACT The essential oil composition of the Ocotea bicolor, native plant of Brazil, was studied for the first time. The essential oil of the leaf was obtained by hydrodistillation and analyzed by GC/MS. The analytical procedure revealed a predominance of sesquiterpenes, δ-cadinene (7.39%), ß-sesquiphellandrene (6.67%), ß-elemene (5.41%) and α-cadinol (5,23%). The essential oil was submitted to brine shrimp toxicity evaluation, antioxidant and antibacterial tests. The antioxidant activity by the formation of phosphomolybdenum complex method presented positive results. The minimum inhibitory concentration (MIC) values were higher than 1000 µg/mL for the microorganisms tested. Toxicity activity revealed LC50 results of 40.10 (µg/mL), being toxic to the organisms in this study
Assuntos
Óleos Voláteis/análise , Lauraceae/classificação , Lauraceae/química , Antioxidantes/análise , Plantas Medicinais/anatomia & histologia , Ocotea/efeitos adversosRESUMO
The complete chloroplast genome of Cinnamomum kanehirae (Hayata), the first to be completely sequenced of Lauraceae family, is presented in this study. The total genome size is 152,700 bp, with a typical circular structure including a pair of inverted repeats (IRa/b) of 20,107 bp of length separated by a large single-copy region (LSC) and a small single-copy region (SSC) of 93,642 bp and 18,844 bp of length, respectively. The overall GC content of the genome is 39.1%. The nucleotide sequence shows 91% identities with Liriodendron tulipifera in the Magnoliaceae. In total, 123 annotated genes consisted of 79 coding genes, eight rRNA genes, and 36 tRNA genes. Among all 79 coding genes, seven genes (rpoC1, atpF, rpl2, ndhB, ndhA, rps16, and rpl2) contain one intron, while two genes (ycf3 and clpP) contain two introns. The maximum likelihood phylogenetic analysis revealed that C. kanehirae chloroplast genome is closely related to Calycanthus fertilis within Laurales order.
Assuntos
Genoma de Cloroplastos/genética , Genoma Mitocondrial/genética , Lauraceae/genética , Composição de Bases/genética , Evolução Molecular , Lauraceae/classificação , Filogenia , RNA Ribossômico/genética , RNA de Transferência/genéticaRESUMO
The genus Nectandra belongs to the Ocotea complex and these species (Nectandra) are generally trees. It is considered endemic in the Neotropics. This genus has been reported uses in folk medicine as antifungal, anti-inflammatory, antimalarial, analgesic, treatment of ulcers, and febrifuge, among others; have also been reported some biological activity assays including: antitumor and antimalarial activity, activity against cardiovascular disease, among others. The genus Nectandra contains different secondary metabolites and they have been reported: Alkaloids; such as aporfinic, proaporfin, benzylisoquinoline, bisbenzylisoquinoline, and morfinandienone-type; lignans and neolignans, furofuran, benzofuran, tetrahydrofuran and dihydrofuran, and 3,3-neolignans-type; terpenes and sesquiterpenoid (monocyclic and bicyclic); Phytosterols and derived from those (3-hydroxy and the 3-ketone pentacyclic compounds); flavonoids, particularly O- glycosylated; xanthones, phenolic acids, polyalcohol, and alkene-alkyne, especially rubrenolide and rubrynolide.
El género Nectandra pertenece al complejo Ocotea y estas especies (Nectandra) son por lo general árboles. Se considera endémica en el Neotrópico. Este género se ha informado de usos en medicina popular como antifúngico, anti-inflamatorio, antimalárico, analgésico, el tratamiento de las úlceras, y febrífugo, entre otros; También se han informado de algunos ensayos de actividad biológica, incluyendo: antitumoral y actividad antipalúdica, actividad contra las enfermedades cardiovasculares, entre otros. El género Nectandra contiene diferentes metabolitos secundarios y se han reportado alcaloides; tales como aporfinas, proaporfina, benzylisoquinolina, y del tipo morfinandienona; lignanos y neolignanos, furofuran, benzofurano, tetrahidrofurano y dihidrofurano, y del tipo 3,3-neolignanos; terpenos y sesquiterpenoide (monocíclicos y bicíclicos); Los fitoesteroles se derivan de aquellos (3-hidroxi y los compuestos pentacíclicos 3-cetona); flavonoides, particularmente O-glicosilada; xantonas, ácidos fenólicos, polialcohol, y alqueno-alquino, especialmente rubrenolide y rubrynolida.
Assuntos
Alcaloides/química , Lauraceae/química , Medicina Tradicional , Etnobotânica , Lauraceae/classificaçãoRESUMO
Fengshui forests (sacred groves) are important in traditional Chinese culture and home to many endangered species. These forests may provide protection for some endangered plant species outside the nature reserves, but little is known about their role in genetic conservation. Using inter-simple sequence repeat (ISSR) markers, we compared the genetic diversity of 6 populations of Phoebe bournei (Hemsl.) Yang, a commercially important woody species, which is under second-class national protection and endemic to China. Samples were collected from the nature reserves and Fengshui forests in southern China. Herein, we show that Fengshui forest populations are capable of maintaining some level of genetic diversity. For nature reserve populations, the average NA and NE were 1.58 and 1.39, respectively; and for Fengshui forests, they were 1.39 and 1.12, respectively. For nature reserve populations, Nei's gene diversity (H) and Shannon's index (I) were 0.32 and 0.11, respectively; and for Fengshui forests, they were 0.22 and 0.07, respectively. We discuss the reasons for the genetic differences between populations of the Fengshui forests and nature reserves and propose conservation strategies for the Fengshui forest.
Assuntos
Florestas , Genética Populacional , Lauraceae/genética , China , Espécies em Perigo de Extinção , Variação Genética , Lauraceae/classificação , Repetições de Microssatélites , Filogenia , FilogeografiaRESUMO
Nectandra megapotamica (Spreng.) Mez. is a tree species that naturally occurs in the Atlantic Forest, Brazil. The aim of this study was to evaluate the genetic diversity and structure of a natural population of 12 N. megapotamica individuals using random amplified polymorphic DNA markers. Eleven primers were used in this study, producing 81 bands, of which 98.99% were polymorphic. Analysis using STRUCTURE defined three different clusters (K = 3), results that were consistent with those of principal coordinates analysis. Both Nei's genetic diversity (h = 0.33) and Shannon's diversity index (I = 0.49) were relatively high. Analysis of molecular variance indicated that 24.89% of the genetic variability was among clusters, while the remaining 75.11% was within clusters. The Mantel test showed a weak correlation between genetic and geographic distances (r = 0.25, P = 0.105). Overall, the results revealed high levels of genetic diversity within clusters and high genetic differentiation among clusters without any spatial pattern of genetic variability. In addition, gene flow was independent of the geographical distribution and was compatible with the hierarchical island model.
Assuntos
Marcadores Genéticos , Variação Genética , Genética Populacional , Lauraceae/genética , Alelos , Análise por Conglomerados , Evolução Molecular , Lauraceae/classificação , Técnica de Amplificação ao Acaso de DNA PolimórficoRESUMO
Spatial distribution pattern of biological related species present unique opportunities and challenges to explain species coexistence. In this study, we explored the spatial distributions and associations among congeneric species at both the species and genus levels to explain their coexistence through examining the similarities and differences at these two levels. We first used DNA and cluster analysis to confirmed the relative relationship of eight species within a 20 ha subtropical forest in southern China. We compared Diameter at breast height (DBH) classes, aggregation intensities and spatial patterns, associations, and distributions of four closely related species pairs to reveal similarities and differences at the species and genus levels. These comparisons provided insight into the mechanisms of coexistence of these congeners. O-ring statistics were used to measure spatial patterns of species. Ω0-10, the mean conspecific density within 10 m of a tree, was used as a measure of the intensity of aggregation of a species, and g-function was used to analyze spatial associations. Our results suggested that spatial aggregations were common, but the differences between spatial patterns were reduced at the genus level. Aggregation intensity clearly reduced at the genus level. Negative association frequencies decreased at the genus level, such that independent association was commonplace among all four genera. Relationships between more closely related species appeared to be more competitive at both the species and genus levels. The importance of competition on interactions is most likely influenced by similarity in lifestyle, and the habitat diversity within the species' distribution areas. Relatives with different lifestyles likely produce different distribution patterns through different interaction process. In order to fully understand the mechanisms generating spatial distributions of coexisting siblings, further research is required to determine the spatial patterns and associations at other classification levels.
Assuntos
Lauraceae/classificação , Lauraceae/genética , Análise Espacial , Biodiversidade , China , Filogenia , Especificidade da EspécieRESUMO
The invasive redbay ambrosia beetle, Xyleborus glabratus, is the primary vector of Raffaelea lauricola, a symbiotic fungus and the etiologic agent of laurel wilt. This lethal disease has caused severe mortality of redbay (Persea borbonia) and swampbay (P. palustris) trees in the southeastern USA, threatens avocado (P. americana) production in Florida, and has potential to impact additional New World species. To date, all North American hosts of X. glabratus and suscepts of laurel wilt are members of the family Lauraceae. This comparative study combined field tests and laboratory bioassays to evaluate attraction and boring preferences of female X. glabratus using freshly-cut bolts from nine species of Lauraceae: avocado (one cultivar of each botanical race), redbay, swampbay, silkbay (Persea humilis), California bay laurel (Umbellularia californica), sassafras (Sassafras albidum), northern spicebush (Lindera benzoin), camphor tree (Cinnamomum camphora), and lancewood (Nectandra coriacea). In addition, volatile collections and gas chromatography-mass spectroscopy (GC-MS) were conducted to quantify terpenoid emissions from test bolts, and electroantennography (EAG) was performed to measure olfactory responses of X. glabratus to terpenoids identified by GC-MS. Significant differences were observed among treatments in both field and laboratory tests. Silkbay and camphor tree attracted the highest numbers of the beetle in the field, and lancewood and spicebush the lowest, whereas boring activity was greatest on silkbay, bay laurel, swampbay, and redbay, and lowest on lancewood, spicebush, and camphor tree. The Guatemalan cultivar of avocado was more attractive than those of the other races, but boring response among the three was equivalent. The results suggest that camphor tree may contain a chemical deterrent to boring, and that different cues are associated with host location and host acceptance. Emissions of α-cubebene, α-copaene, α-humulene, and calamenene were positively correlated with attraction, and EAG analyses confirmed chemoreception of terpenoids by antennal receptors of X. glabratus.
Assuntos
Lauraceae/química , Lauraceae/parasitologia , Terpenos/isolamento & purificação , Gorgulhos/fisiologia , Animais , Feminino , Cromatografia Gasosa-Espectrometria de Massas/métodos , Lauraceae/classificação , Feromônios/isolamento & purificação , Extratos Vegetais/química , Olfato , Estados UnidosRESUMO
Muitas plantas são utilizadas pela população para o tratamento e a cura de doenças. Entre elas encontram-se a Persea major Kopp, Piper mollicomum Kunth. e Serjania erecta Radlk. as quais são utilizadas para diversas enfermidades, inclusive para tratar distúrbios do trato gastrointestinal. O objetivo deste trabalho foi estudar os efeitos dos extratos dessas três plantas sobre a motilidade gastrointestinal. Camundongos Swiss foram tratados com os extratos pela via oral 1 hora antes da administração de uma solução semisólida de carboximetilcelulose 1,5% e vermelho de fenol 0,05% e, após 15 minutos, o esvaziamento gástrico e o trânsito intestinal avaliados. O extrato hidroalcoólico da P. major (100 a 1000 mg Kg-1, p.o.) e o extrato hidroalcoólico da P. mollicomum (100 e 300 mg Kg-1, p.o.) aumentaram o trânsito intestinal. No entanto, somente o extrato da P. major (100 e 300 mg Kg-1) também aumentou o esvaziamento gástrico. O extrato etanólico da S. erecta (100 a 1000 mg Kg-1, p.o.) não alterou a motilidade gastrointestinal. Estes resultados sugerem que a Persea major e a Piper mollicomum mereçam estudos mais aprofundados em busca de princípios ativos ou matéria vegetal efetiva para o tratamento de distúrbios do trato gastrointestinal como a constipação.
Many plants are popularly used for the treatment and healing of diseases. The Persea major Kopp, Piper mollicomum Kunth. and Serjania erecta Radlk. are used in several illnesses, including the treatment of disorders of the gastrointestinal tract. The aim of this study was to evaluate the effects of the extracts of these plants on the gastrointestinal motility. Swiss mice were orally treated with extracts one hour before the administration of a semisolid solution of 1.5% carboxymethylcellulose and 0.05% phenol red. After 15 minutes, the gastric emptying and intestinal transit were determined. The hydroalcoholic extract of P. major (100 to 1000 mg Kg-1, p.o.) and the hydroalcoholic extract of P. mollicomum (100 and 300 mg Kg-1, p.o.) increased the intestinal transit. However, only the P. major extract (100 and 300 mg Kg-1) increased the gastric emptying. The ethanolic extract of S. erecta (100 to 1000 mg Kg-1, p.o.) did not alter the gastrointestinal motility. These results suggest that Persea major and Piper mollicomum can be of interest for further studies in the search of active principles or effective plant material for the treatment of disorders of the gastrointestinal tract, such as constipation.
Assuntos
Animais , Masculino , Feminino , Ratos , Plantas Medicinais/metabolismo , Extratos Vegetais/análise , Trato Gastrointestinal/fisiopatologia , Lauraceae/classificação , Piper/classificação , Esvaziamento Gástrico/fisiologiaRESUMO
Topography is a factor that can significantly affect the diversity and the distribution of trees species in tropical forests. Aniba perutilis, a timber species listed as vulnerable to extinction, is widely distributed in Andean forest fragments, especially in those with highly variable topography. Based on field surveys and logistic regression analyses, we studied the population structure and the effect of highly variable topography on the spatial distribution of this tree in three protected forest fragments in the central Andes of Colombia. Individuals of A. perutilis were mainly found on mountain ridges and hills with gentle slopes; no individuals were found in valleys. Using a species distribution model with presence/absence data, we showed that the available habitat for A. perutilis is significantly smaller than the extension of the fragments and much smaller than the extension of the currently protected areas. Our results have important implications for the conservation ofA. perutilis and likely for other threatened Andean tree species, which can also have locally restricted distributions due to highly variable local topography.