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Characterization of unisexual flower development in the endangered mahogany tree Swietenia macrophylla King. (Meliaceae)

GOUVEA, Cantidio Fernando; DORNELAS, Marcelo Carnier; MARTINELLI, Adriana Pinheiro
Fonte: BLACKWELL PUBLISHING Publicador: BLACKWELL PUBLISHING
Tipo: Artigo de Revista Científica
ENG
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27.52%
The selection of candidate plus trees of desirable phenotypes from tropical forest trees and the rapid devastation of the natural environments in which these trees are found have created the need for a more detailed knowledge of the floral and reproductive biology of tropical tree species. In this article, the organogenic processes related to unisexual flower development in tropical mahogany, Swietenia macrophylla, are described. Mahogany inflorescences at different developmental stages were evaluated using scanning electron microscopy or optical microscopy of histological sections. The unisexual flowers of S. macrophylla are usually formed in a thyrse, in which the positions of the female and male flowers are not random. Differences between male and female flowers arise late during development. Both female and male flowers can only be structurally distinguished after stage 9, where ovule primordia development is arrested in male flowers and microspore development is aborted in female flower anthers. After this stage, male and female flowers can be distinguished by the naked eye as a result of differences in the dimensions of the gynoecium. The floral characteristics of S. macrophylla (distribution of male and female flowers within the inflorescence...

How rare is too rare to harvest? Management challenges posed by timber species occurring at low densities in the Brazilian Amazon

SCHULZE, Mark; GROGAN, James; LANDIS, R. Matthew; VIDAL, Edson
Fonte: ELSEVIER SCIENCE BV Publicador: ELSEVIER SCIENCE BV
Tipo: Artigo de Revista Científica
ENG
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Tropical forests are characterized by diverse assemblages of plant and animal species compared to temperate forests. Corollary to this general rule is that most tree species, whether valued for timber or not, occur at low densities (<1 adult tree ha(-1)) or may be locally rare. In the Brazilian Amazon, many of the most highly valued timber species occur at extremely low densities yet are intensively harvested with little regard for impacts on population structures and dynamics. These include big-leaf mahogany (Swietenia macrophylla), ipe (Tabebuia serratifolia and Tabebuia impetiginosa), jatoba (Hymenaea courbaril), and freijo cinza (Cordia goeldiana). Brazilian forest regulations prohibit harvests of species that meet the legal definition of rare - fewer than three trees per 100 ha - but treat all species populations exceeding this density threshold equally. In this paper we simulate logging impacts on a group of timber species occurring at low densities that are widely distributed across eastern and southern Amazonia, based on field data collected at four research sites since 1997, asking: under current Brazilian forest legislation, what are the prospects for second harvests on 30-year cutting cycles given observed population structures...

What loggers leave behind: Impacts on big-leaf mahogany (Swietenia macrophylla) commercial populations and potential for post-logging recovery in the Brazilian Amazon

GROGAN, James; JENNINGS, Stephen B.; LANDIS, R. Matthew; SCHULZE, Mark; BAIMA, Anadilza M. V.; LOPES, J. do Carmo A.; NORGHAUER, Julian M.; OLIVEIRA, L. Rogerio; PANTOJA, Frank; PINTO, Diane; SILVA, Jose Natalino M.; VIDAL, Edson; ZIMMERMAN, Barbara L.
Fonte: ELSEVIER SCIENCE BV Publicador: ELSEVIER SCIENCE BV
Tipo: Artigo de Revista Científica
ENG
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37.95%
The sustainability of current harvest practices for high-value Meliaceae can be assessed by quantifying logging intensity and projecting growth and survival by post-logging populations over anticipated intervals between harvests. From 100%-area inventories of big-leaf mahogany (Swietenia macrophylla) covering 204 ha or more at eight logged and unlogged forest sites across southern Brazilian Amazonia, we report generally higher landscape-scale densities and smaller population-level mean diameters in eastern forests compared to western forests, where most commercial stocks survive. Density of trees >= 20 cm diameter varied by two orders of magnitude and peaked at 1.17 ha(-1). Size class frequency distributions appeared unimodal at two high-density sites, but were essentially arnodal or flat elsewhere; diameter increment patterns indicate that populations were multi- or all-aged. At two high-density sites, conventional logging removed 93-95% of commercial trees (>= 45 cm diameter at the time of logging), illegally eliminated 31-47% of sub-merchantable trees, and targeted trees as small as 20 cm diameter. Projected recovery by commercial stems during 30 years after conventional logging represented 9.9-37.5% of initial densities and was highly dependent on initial logging intensity and size class frequency distributions of commercial trees. We simulated post-logging recovery over the same period at all sites according to the 2003 regulatory framework for mahogany in Brazil...

Variation of wood density and relationship with the tree-ring width of mahogany trees, Swietenia macrophylla, from Amazonian tropical forest of Peru

ALVARADO, Jedi Rosero; TOMAZELLO FILHO, Mario; POLLITO, Percy Amilcar Zevallos; LOBAO, Moises Silveira
Fonte: IPEF-INST PESQUISAS ESTUDOS FLORESTAIS Publicador: IPEF-INST PESQUISAS ESTUDOS FLORESTAIS
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
38.02%
Mahogany trees, Swietenia macrophylla, occur in open rainforest, semi deciduous and deciduous and dense rainforest of Peruvian Amazonian tropical forest. They occur, preferentially, in areas with a defined dry season, with typical phenology and seasonal variation activity, forming distinct tree-rings. The present work had as aim to determine the wood density radial variation of 14 mahogany trees, of two populations of the Peruvian Amazonian tropical forest, through the X-ray densitometry and to evaluate their application as methodology, compared to the classic method of measurement table, for the determination of the treering width. The radial wood apparent density of the trees profiles rendered it possible to delimit the areas of juvenile-adult wood and of the heartwood-sapwood, relative to the anatomical structure and chemical composition differences, due to the extractives and the vessels obstruction by tyloses. The mean, minimum and maximum wood apparent density of the mahogany trees for the Populations A and B were of 0.70; 0.29; 1.01 g.cm(-3) and 0.81; 0.29; 1.19 g.cm(-3), respectively. The analysis of the variance and mean test indicate differences of mean wood density among the mahogany trees of each population, probably due to the age of the trees. There was no correlation between mean wood density of mahogany trees among the two populations...

Dendrocronologia de árvores de mogno, Swietenia macrophylla King., Meliaceae, ocorrentes na floresta tropical Amazônica do Departamento de Madre de Dios, Peru; Dendrochronology of the mahogany trees, Swietenia macrophylla King., Meliaceae, occurring in the Amazon Rainforest of the Department of Madre de Dios, Peru

Rosero Alvarado, Jedi
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 15/04/2009 PT
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Estudos sobre a fenologia e anatomia do lenho de árvores de espécies tropicais revelam um desenvolvimento e crescimento cíclicos, relacionados com as condições climáticas (temperatura e precipitação) e de sítio (competição, luz, armazenamento de água no solo, etc.). A sensibilidade a estes fatores resulta, para as árvores de algumas espécies, na sazonalidade da atividade cambial e na formação de anéis de crescimento anuais. Essa característica possibilita a determinação da idade, da taxa de crescimento em diâmetro do tronco e da reconstrução de eventos climáticos, bem como na aplicação de técnicas de manejo florestal sustentável. No presente trabalho, foram aplicadas as técnicas de dendrocronologia, em árvores de mogno, de duas populações na floresta tropical Amazônica do Peru, visando a (i) caracterização da estrutura macro e microscópica do lenho e dos anéis de crescimento, (ii) comprovação da anualidade da formação dos anéis de crescimento e determinação da idade das árvores, (iii) avaliação da biodeterioração do lenho das árvores, (iv) aplicação da densitometria de raios X no estudo do lenho e dos anéis de crescimento e (v) aplicação dos anéis de crescimento em dendroclimatologia e dendroecologia. Foram selecionadas 20 árvores de mogno em duas populações localizadas no Departamento de Madre de Dios...

Nutritional status and specific leaf area of mahogany and tonka bean under two light environments

Gonçalves,José Francisco de C.; Vieira,Gil; Marenco,Ricardo A.; Ferraz,João Baptista S.; Santos Junior,Ulysses Moreira dos; Barros,Francisco Cleber F.
Fonte: Instituto Nacional de Pesquisas da Amazônia Publicador: Instituto Nacional de Pesquisas da Amazônia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2005 EN
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27.21%
Studies on nutritional status and leaf traits were carried out in two tropical tree species Swietenia macrophylla King (mahogany) and Dipetryx odorata Aubl. Willd. (tonka bean) planted under contrasting light environments in Presidente Figueiredo-AM, Brazil. Leaves of S. macrophylla and D. odorata were collected in three year-old trees grown under full sunlight (about 2000 µmol m-2 s-1) and natural shade under a closed canopy of Balsa-wood plantation (Ochroma pyramidale Cav. Ex. Lam.Urb) about 260 µmol m-2 s-1. The parameters analysed were leaf area (LA), leaf dry mass (LDM), specific leaf area (SLA) and leaf nutrient contents. It was observed that, S. macrophylla leaves grown under full sunlight showed LA 35% lower than those grown under shade. In D. odorata leaves these differences in LA were not observed. In addition, it was observed that S. macrophylla shade leaves, for LDM, were 50% smaller than sun leaves, while in D. odorata, there differences were not observed. SLA in S. macrophylla presented that sun leaves were three times smaller than those grown under shade. In D. odorata, no differences were observed. Nutrient contents in S. macrophylla, regardless of their light environments, showed higher contents for P and Ca than those found in D. odorata. The N...

Conservative nutrient use by big-leaf mahogany (Swietenia macrophylla king) planted under contrasting environmental conditions

Medina,Ernesto; Cuevas,Elvira; Lugo,Ariel E.; Terezo,Evaristo; Jiménez-Osornio,Juan; Macario-Mendoza,Pedro Antonio; Montañez,Patricia
Fonte: Sociedade de Investigações Florestais Publicador: Sociedade de Investigações Florestais
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2014 EN
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We analyzed the nutritional composition and isotope ratios (C and N) of big-leaf mahogany (Swietenia macrophylla King) leaves in plantations established on contrasting soils and climates in Central America (State of Quintana Roo, Yucatán, México) and South America (State of Pará, Brazil). The objective was to determine the adaptability of this species to large differences in nutrient availability and rainfall regimes. Nutrient concentrations of leaves and soils were determined spectrophotometrically, and isotope ratios were measured using mass spectrometric techniques.In Pará soils were sandier, and acidic, receiving above 2000 mm of rain, whereas in Quintana Roo soils were predominantly clayey, with neutral to alkaline pH due to the underlying calcareous substrate, with about 1300 mm of rain. Leaf area/weight ratio was similar for both sites, but leaves from Quintana Roo were significantly smaller. Average N and K concentrations of adult leaves were similar, whereas Ca concentration was only slightly lower in Pará in spite of large differences in Ca availability. Leaves from this site had slightly higher P and lower Al concentrations. Differences in water use efficiency as measured by the natural abundance of 13C were negligible...

Phytochemicals and antimicrobial potentials of mahogany family

Paritala,Vikram; Chiruvella,Kishore K.; Thammineni,Chakradhar; Ghanta,Rama Gopal; Mohammed,Arifullah
Fonte: Sociedade Brasileira de Farmacognosia Publicador: Sociedade Brasileira de Farmacognosia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2015 EN
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Drug resistance to human infectious diseases caused by pathogens lead to premature deaths through out the world. Plants are sources for wide variety of drugs used for treating various diseases. Systematic screening of medicinal plants for the search of new antimicrobial drug candidates that can inhibit the growth of pathogens or kill with no toxicity to host is being continued by many laboratories. Here we review the phytochemical investigations and biological activities of Meliaceae. The mahogany (Meliaceae) is family of timber trees with rich source for limonoids. So far, amongst the different members of Meliaceae, Azadirachta indica and Melia dubia have been identified as the potential plant systems possessing a vast array of biologically active compounds which are chemically diverse and structurally complex. Despite biological activities on different taxa of Meliaceae have been carried out, the information of antibacterial and antifungal activity is a meager with exception to Azadirachta indica. Together we provide new insights of Meliaceae members demonstrating as a potential source as antimicrobial agents using in vitro studies.

Concentration of photosynthetic pigments and chlorophyll fluorescence of mahogany and tonka bean under two light environments

GONÇALVES,JOSÉ FRANCISCO DE CARVALHO; MARENCO,RICARDO ANTONIO; VIEIRA,GIL
Fonte: Sociedade Brasileira de Fisiologia Vegetal Publicador: Sociedade Brasileira de Fisiologia Vegetal
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2001 EN
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This study was carried out in a plantation of a degraded area in Central Amazon, Brazil, in order to assess environmental light effects on leaf pigment concentrations and chlorophyll a fluorescence in mahogany (Swietenia macrophylla King) and tonka bean (Dipteryx odorata Aubl. Willd). Three-year old saplings were grown in an open site (sun) with maximum radiation of approximately 2000 mumol m-2 s-1 and under the shade of a Ochroma pyramidale (Cav. ex Lam. Urb) canopy. A leaf area index of 2.46 was optically determined for the Ochroma foliage with 13% of full sunlight (maximum radiation about 260 mumol m-2 s-1). Carotenoid and chlorophyll concentrations were spectrophotometrically determined. Initial (Fo), maximum (Fm) and variable fluorescence (Fv) were determined with a portable fluorometer. Chlorophyll concentrations (Chl a, Chl b and Chl tot) on a fresh mass basis were greater in shade leaves than in sun acclimated leaves in both species. On the other hand, when comparisons were made on a per area basis, Chl a concentrations were greater in the sun than in shade leaves of tonka bean. In contrast, Chl b concentrations were higher in the shade environment for this species. No differences were observed in Chl concentrations per unit area in mahogany leaves. Carotenoid concentrations were higher for sun-acclimated leaves of mahogany...

Mahogany (mg) stimulates feeding and increases basal metabolic rate independent of its suppression of agouti

Dinulescu, Daniela M.; Fan, Wei; Boston, Bruce A.; McCall, Kathleen; Lamoreux, M. Lynn; Moore, Karen J.; Montagno, Jill; Cone, Roger D.
Fonte: The National Academy of Sciences Publicador: The National Academy of Sciences
Tipo: Artigo de Revista Científica
Publicado em 13/10/1998 EN
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The mahogany (mg) locus originally was identified as a recessive suppressor of agouti, a locus encoding a skin peptide that modifies coat color by antagonizing the melanocyte-stimulating hormone receptor or MC1-R. Certain dominant alleles of agouti cause an obesity syndrome when ectopic expression of the peptide aberrantly antagonizes the MC4-R, a related melanocyte-stimulating hormone receptor expressed in hypothalamic circuitry and involved in the regulation of feeding behavior and metabolism. Recent work has demonstrated that mg, when homozygous, blocks not only the ability of agouti to induce a yellow coat color when expressed in the skin of the lethal yellow mouse (AY), but also the obesity resulting from ectopic expression of agouti in the brain. Detailed analysis of mg/mg AY/a animals, presented here, demonstrates that mg/mg blocks the obesity, hyperinsulinemia, and increased linear growth induced by ectopic expression of the agouti peptide. Remarkably, however, mg/mg did not reduce hyperphagia in the AY/a mouse. Furthermore, mg/mg induced hyperphagia and an increase in basal metabolic rate in the C57BL/6J mouse in the absence of AY. Consequently, although mahogany is broadly required for agouti peptide action, it also appears to be involved in the control of metabolic rate and feeding behavior independent of its suppression of agouti.

The Importance of Tree Size and Fecundity for Wind Dispersal of Big-Leaf Mahogany

Norghauer, Julian M.; Nock, Charles A.; Grogan, James
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 07/03/2011 EN
Relevância na Pesquisa
27.52%
Seed dispersal by wind is a critical yet poorly understood process in tropical forest trees. How tree size and fecundity affect this process at the population level remains largely unknown because of insufficient replication across adults. We measured seed dispersal by the endangered neotropical timber species big-leaf mahogany (Swietenia macrophylla King, Meliaceae) in the Brazilian Amazon at 25 relatively isolated trees using multiple 1-m wide belt transects extended 100 m downwind. Tree diameter and fecundity correlated positively with increased seed shadow extent; but in combination large, high fecundity trees contributed disproportionately to longer-distance dispersal events (>60 m). Among three empirical models fitted to seed density vs. distance in one dimension, the Student-t (2Dt) generally fit best (compared to the negative exponential and inverse power). When seedfall downwind was modelled in two dimensions using a normalised sample, it peaked furthest downwind (c. 25 m) for large, high-fecundity trees; with the inverse Gaussian and Weibull functions providing comparable fits that were slightly better than the lognormal. Although most seeds fell within 30 m of parent trees, relatively few juveniles were found within this distance...

Shifts in reproductive assurance strategies and inbreeding costs associated with habitat fragmentation in Central American mahogany

Breed, Martin F; Gardner, Michael G; Ottewell, Kym M; Navarro, Carlos M; Lowe, Andrew J
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
Publicado em /05/2012 EN
Relevância na Pesquisa
27.52%
The influence of habitat fragmentation on mating patterns and progeny fitness in trees is critical for understanding the long-term impact of contemporary landscape change on the sustainability of biodiversity. We examined the relationship between mating patterns, using microsatellites, and fitness of progeny, in a common garden trial, for the insect-pollinated big-leaf mahogany, Swietenia macrophylla King, sourced from forests and isolated trees in 16 populations across Central America. As expected, isolated trees had disrupted mating patterns and reduced fitness. However, for dry provenances, fitness was negatively related to correlated paternity, while for mesic provenances, fitness was correlated positively with outcrossing rate and negatively with correlated paternity. Poorer performance of mesic provenances is likely because of reduced effective pollen donor density due to poorer environmental suitability and greater disturbance history. Our results demonstrate a differential shift in reproductive assurance and inbreeding costs in mahogany, driven by exploitation history and contemporary landscape context.

Wood typification by Venturi easy ambient sonic spray ionization mass spectrometry: the case of the endangered Mahogany tree

Cabral, Elaine Cristina; Simas, Rosineide Costa; Santos, Vanessa Goncalves dos; Queiroga, Carmen Lucia; Cunha, Valnei Smarçaro da; Sá, Gilberto Fernandes de; Daroda, Romeu José; Eberlin, Marcos Nogueira
Fonte: Inmetro - Instituto Nacional de Metrologia, Qualidade e Tecnologia Publicador: Inmetro - Instituto Nacional de Metrologia, Qualidade e Tecnologia
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
27.85%
6 p. : il.; Venturi easy ambient sonic spray ionization mass spectrometry in both its liquid (VL-EASI-MS) and solid samplemodes (VS-EASI-MS) is shown to provide nearly immediate and secure typification of woods, as demonstrated for Mahogany, an endangered and most valuable type of tropical wood. This reddish wood displays unique phytochemical markers (phragmalin-type limonoids) which are rapidly detected from the wood surface by VS-EASI-MS or from a simple methanol extract of a tiny wood chip by VL-EASI-MS. Unique profiles were obtained for Mahogany (Swietenia macrophylla) whereas genuine samples of six other similar types of woods, which are commonly falsified by artificial coloring and commercialized as Mahogany, display also typical but dissimilar pythochemical profiles as compared to that of the authentic wood. Variable and atypical chemical profiles were observed for artificially colored woods. Secure chemical characterization via VS-EASI-MS or Vs-EASI-MS fingerprints of Mahogany and other types of woods with similar appearance should help to control the illegal logging and trade of this and other endangered woods and their falsification, and to create certified standards. Copyright © 2012 John Wiley & Sons, Ltd.

Two men looking at a mahogany tree in the Royal Botanic Gardens of Trinidad and Tobago; The Bryant Slides Collection; The Bryant Slides Collection, Trinidad

Unknown ( Photographer )
Fonte: Universidade da Flórida Publicador: Universidade da Flórida
Tipo: still image Formato: 35 mm
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The slides were taken on collecting trips sponsored by the William L. Bryant Foundation, where books, music and art indigenous to the regions were gathered. The are organized by geographical location.; The Royal Botanic Gardens of Trinidad and Tobago, first opened in 1818, are located on the northern side of Queen’s Park Savannah in Port of Spain, Trinidad. In this image a park guide points out a mahogany tree, growing near a paved path, to a visitor. Hibiscuses, bougainvilleas, and palm trees can be seen. Slide labeled Mahogany Tree Trinidad.

Chloroplast DNA microsatellites reveal contrasting phylogeographic structure in mahogany (Swietenia macrophylla King, Meliaceae) from Amazonia and Central America

Lemes, M.; Dick, C.; Navarro, C.; Lowe, A.; Cavers, S.; Gribel, R.
Fonte: Springer New York LLC Publicador: Springer New York LLC
Tipo: Artigo de Revista Científica
Publicado em //2010 EN
Relevância na Pesquisa
37.72%
Big-leaf mahogany (Swietenia macrophylla King) is one of the most valuable and overharvested timber trees of tropical America. In order to better characterize geographic patterns of genetic variation, we performed a phylogeographic analysis of S. macrophylla based on six polymorphic chloroplast genome simple sequence repeat loci (cpSSRs) analyzed in 16 populations (N  = 245 individuals) distributed across Central America and the Brazilian Amazon. Of the 31 total cpDNA haplotypes identified, 16 occurred in Central America and 15 in Amazonia with no single haplotype shared between the two regions. Populations from Central America showed moderate differentiation (F ST  = 0.36) while within population genetic diversity was generally high (mean Nei’s H E  = 0.639). In contrast, the Amazonian populations were strongly differentiated (F ST  = 0.91) and contained relatively low genetic diversity (mean H E  = 0.176), except for one highly diverse population (H E  = 0.925) from eastern Amazonia. Spatial analysis of molecular variance (SAMOVA) identified a single Central American phylogroup and four Amazonian phylogroups, indicating stronger phylogeographic structure within Amazonia. The results demonstrate distinctive regional patterns of S. macrophylla differentiation...

Shifts in reproductive assurance strategies and inbreeding costs associated with habitat fragmentation in Central American mahogany

Breed, M.; Gardner, M.; Ottewell, K.; Navarro, C.; Lowe, A.
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
Publicado em //2012 EN
Relevância na Pesquisa
27.52%
The influence of habitat fragmentation on mating patterns and progeny fitness in trees is critical for understanding the long-term impact of contemporary landscape change on the sustainability of biodiversity. We examined the relationship between mating patterns, using microsatellites, and fitness of progeny, in a common garden trial, for the insect-pollinated big-leaf mahogany, Swietenia macrophylla King, sourced from forests and isolated trees in 16 populations across Central America. As expected, isolated trees had disrupted mating patterns and reduced fitness. However, for dry provenances, fitness was negatively related to correlated paternity, while for mesic provenances, fitness was correlated positively with outcrossing rate and negatively with correlated paternity. Poorer performance of mesic provenances is likely because of reduced effective pollen donor density due to poorer environmental suitability and greater disturbance history. Our results demonstrate a differential shift in reproductive assurance and inbreeding costs in mahogany, driven by exploitation history and contemporary landscape context.; Martin F. Breed, Michael G. Gardner, Kym M. Ottewell, Carlos M. Navarro and Andrew J. Lowe; Article first published online: 1 Mar 2012

Diversidade genética em população de melhoramento de mogno africano (Khaya ivorensis A. Chev.); Genetic diversity in breeding population of african mahogany (Khaya ivorensis)

Soares, Sabrina Delgado
Fonte: Universidade Federal de Goiás; Brasil; UFG; Programa de Pós-graduação em Genetica e Biologia Molecular; Instituto de Ciências Biológicas - ICB (RG) Publicador: Universidade Federal de Goiás; Brasil; UFG; Programa de Pós-graduação em Genetica e Biologia Molecular; Instituto de Ciências Biológicas - ICB (RG)
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
27.85%
The strong demand for hardwood drives selective logging and degradation of forests ecossystems in Brazil. Due to its wood value and predatory logging, Brazilian mahogany (Swietenia macrophylla) is at risk of extinction. Currently, its trees are protected and banned from logging by the Brazilian Institute of Environment (IBAMA). Monoculture of the Brazilian mahogany is proven unsuccessful due to the attack of the Hypsipyla grandella larvae. An alternative to Brazilian mahogany plantation is the African mahogany (Khaya ivorensis), a species with similar high valued wood properties. The Universidade Federal de Goiás in partnership with Mudas Nobres Company started a breeding program with Khaya ivorensis. The objective of this study was to evaluate the genetic diversity and divergence among 53 superior trees selected and cloned as part of the breeding strategies. Clones were selected from three different populations, planted in two farms in Pará state and originating from Ivory Coast and Tanzania populations. Twelve seedlings of Khaya senegalensis were also used as a control group in the analyses of genetic divergence. The individuals were genotyped with eight microsatellite loci developed for K. senegalensis, by capillary electrophoresis on the ABI-3100 (Applied Biosystems) platform. The software GeneMapper (Applied Biosystems) was used to genotype the alleles. The average number of alleles per locus was 5.875. The average expected heterozygosity was lower (HE = 0.563) than the average observed heterozygosity (HO = 0.738). Therefore...

Indução de deficiências nutricionais em mudas de mogno africano (Khaya ivorensis A. Chev.); Nutritional deficiencies in seedlings of african mahogany (Khaya ivorensis A. Chev.)

Corcioli, Graciella
Fonte: Universidade Federal de Goiás; Brasil; UFG; Programa de Pós-graduação em Agronomia (EAEA); Escola de Agronomia e Engenharia de Alimentos - EAEA (RG) Publicador: Universidade Federal de Goiás; Brasil; UFG; Programa de Pós-graduação em Agronomia (EAEA); Escola de Agronomia e Engenharia de Alimentos - EAEA (RG)
Tipo: Tese de Doutorado Formato: application/pdf
POR
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27.85%
The african mahogany (Khaya ivorensis) is a high value forest essence in the international trade and of great potential to replace the Brazilian mahogany (Swietenia macrophylla), which is one of the most valuable commercial species in the world, but presents serious difficulties in its cultivation. Currently, little is known about the nutritional requirements of the african mahogany. In this sense, this study aimed to characterize and induce the symptoms of the deficiencies of macro nutriens (nitrogen, phosphorus, potassium, calcium, magnesium, sulfur) and micro nutrients (iron, boron, copper, manganese, molybdenum and zinc) based on the diagnosis by the visual method and by means of chemical analysis on seedlings of african mahogany. In order to do that, two experiments were conducted with a nutritive solution with the following treatments: T1-Complete Solution; T2-Complete solution, with the omission of nitrogen; T3-complete solution, with the omission of phosphorus; T4-complete solution, with the omission of potassium, T5-complete solution, with the omission of calcium; T6-complete solution, with the omission of magnesium-T7 complete solution, with the omission of sulfur; T8-complete solution, with the omission of iron; T9-complete solution...

Energetic flux and performance index in copaiba (Copaifera multijuga Hayne) and mahogany (Swietenia macrophylla King) seedlings grown under two irradiance environments

Gonçalves,José F.C.; Santos Jr.,Ulysses M.; Nina Jr.,Adamir R.; Chevreuil,Larissa R.
Fonte: Brazilian Journal of Plant Physiology Publicador: Brazilian Journal of Plant Physiology
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2007 EN
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28.07%
Plant adaptation under conditions of limited irradiance can be investigated by their efficiency while using the available energy with a minimal thermodynamic energy loss. For this reason, we compared the energetic fluxes and the performance index (PI ABS) in copaiba (Copaifera multijuga) and mahogany (Swietenia macrophyla) seedlings under both sunlight and shade. The experiment was carried out in Manaus (3º8'S, 59º52'W), Amazonas State, Brazil. The fluorescence transients were obtained in intact and healthy leaves using a Plant Efficiency Analyser (PEA) between 1200 h and 1300 h. Using the O-J-I-P test, the following parameters were calculated: 1) density of reaction centers per cross section (RC/CS), 2) maximum quantum yield for primary photochemistry of photosystem II (sigmaPo), and 3) probability of energy excitation (psio) or that of an absorbed photon (sigmaEo) to move an electron further than quinone A, and 4) the performance index (PI ABS). The highest PI ABS was found in seedlings under shade for both species. Mahogany seedlings exhibited values of PI ABS about three-fold and 14-fold higher than copaiba seedlings under shade and sunlight, respectively. For RC/CS, reaction centers were inactive under sunlight, 58% for mahogany and 78% for copaiba. The high irradiance induced a decrease of sigmaPo in mahogany (36%) and in copaiba (69%) when compared to shaded seedlings. This likely was a result of need for excess energy dissipation under sunlight. In addition...

Population genetic structure of mahogany (Swietenia macrophylla King, Meliaceae) across the Brazilian Amazon, based on variation at microsatellite loci: implications for conservation

Lemes, Maristerra R.; Gribel, Rogério; Proctor, John; Grattapaglia, Dario
Fonte: Universidade Católica de Brasília Publicador: Universidade Católica de Brasília
Tipo: Artigo de Revista Científica Formato: Texto
EN
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Mahogany ( Swietenia macrophylla , Meliaceae) is the most valuable and intensively exploited Neotropical tree. No information is available regarding the genetic structure of mahogany in South America, yet the region harbours most of the unlogged populations of this prized hardwood. Here we report on the genetic diversity within and the differentiation among seven natural populations separated by up to 2100 km along the southern arc of the Brazilian Amazon basin. We analysed the variation at eight microsatellite loci for 194 adult individuals. All loci were highly variable, with the number of alleles per locus ranging from 13 to 27 (mean = 18.4). High levels of genetic diversity were found for all populations at the eight loci (mean H E = 0.781, range 0.754–0.812). We found moderate but statistically significant genetic differentiation among populations considering both estimators of F ST and R ST , θ = 0.097 and ρ = 0.147, respectively. Estimates of θ and ρ were significantly greater than zero for all pairwise population comparisons. Pairwise ρ -values were positively and significantly correlated with geographical distance under the isolation-by-distance model. Furthermore, four of the populations exhibited a significant inbreeding coefficient. The finding of local differentiation among Amazonian mahogany populations underscores the need for in situ conservation of multiple populations of S. macrophylla across its distribution in the Brazilian Amazon. In addition...