LabGeM___________________________

April 30, 2020

Studies that characterize the effects of climatic factors on the geographic distribution of trees are essential, especially for tropical trees frequently used for wood supply, such as Mimosa tenuiflora (Willd) Poiret (jurema-preta), Fabaceae.

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We asked the following questions: I) Over the years, will climate change negatively affect the occurrence of M. tenuiflora? II) Could areas with low suitability in the present become areas with high suitability in future prediction? III) Will annual rainfall be the variable with the most significant influence in determining the potential suitability of areas? Read More.

December 10, 2019

The Elaeis guineensis palm tree is popularly known as oil palm. Its economic prominence is due to its oil, that can be extracted from both the fruit (palm oil) and the nut (palm kernel oil).

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Through genetic studies of forest populations, knowledge about the genetic variability and the distribution of genotypes in space have been useful for both genetic conservation and genetic improvement.

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This study aimed to estimate the genetic diversity of three E. guineensis populations, as well as to verify the decreases in effective population size. The data obtained in this study will support ex-situ conservation projects for E. guineensis, contributing to the selection of genotypes and their sustainable use. Read More.

October 07, 2019

Protium is a well-known tree genus because of the production of secondary metabolites, mainly classes of terpenes. It is diverse and abundant in the Amazon basin where it can be found in up to 35 sympatric species. However, fragmentation leads to changes in the size and dynamics of forest populations.

Studies of genetic diversity support strategies for preserving the genetic resources and the data to date for the Atlantic Forest in northeast Brazil are scarce. Here, we studied the genetic diversity of natural Protium heptaphyllum populations, evaluating the genetic structure and the occurrence of population/genetic bottlenecks. Read More.

August 30, 2019

The fruits of the mangabeira (Hancornia speciosa) are used mainly in the Brazilian Northeast region to supply the agroindustry sector for the production of juices, sweets, ice cream and other derivatives. The harvest brings in around $1 million per year to Brazil.

The biometry of fruits and seeds is essential to characterize the intra and interpopulational variations, allowing to infer about environmental and genetic factors that determine these divergences. Such information is relevant to support strategies for conservation, management of natural populations and genetic improvement. Read More.

January 31, 2019

Strategies for the maintenance of forest resources have been increasingly important due to the rapid loss of natural habitats. The remaining forests are widely fragmented and mostly located in areas of monoculture and pasture. Thus, the gene flow from the pollen exchange between populations can be altered, as well as seed dispersal.

In the north east of Brazil, real estate speculation and the establishment of monocultures such as coconut, sugar cane, extensive livestock breeding, and various extractive activities are constant threats to the genetic integrity of the natural populations of Hancornia speciosa. Efforts are needed to reconcile conservation of the genetic resource and the sustainable use of H. speciosa. Read More.

September 22, 2017

The palm Copernicia prunifera, commonly known as carnaúba, can be used for a variety of purposes, from urban forestry to wax extraction from its leaves, the main product of the species, which is used in cosmetics, varnishes, and even for polishing fruit. 

The knowledge of the mating systems, as well as preliminary studies, such as reproductive biology, floral structures, and pollinators of a species, are essential to support taxonomy investigations, management strategies, breeding, and domestication of native species.

Thus, we found that the C. prunifera has multiple inflorescences with hermaphroditic flowers and pollen viability of 62%. Outcrossing rates at the population level produced a multilocus outcrossing rate of 0.878 (~88%), indicating that C. prunifera has a mixed mating system that is preferentially allogamous. Floral visits were also recorded by the “maribondo-caboclo” (Polistes canadensis) and by “irapuá” (Trigona spinipes).

That information helps us understand the reproduction mechanism, as well as to define management strategies for the conservation and genetic improvement of the C. prunifera palm. Read more.

January 12, 2017

Compared to other plant families, a large proportion of Orchidaceae genera and species are in danger of extinction. The fragmentation of native forests and illegal extraction have resulted in local extinction of many orchid species. 

Cattleya granulosa is an endangered epiphytic orchid and is threatened by habitat fragmentation, primarily the result of urban development, and predation due to its value as an ornamental plant. Because of these factors, the species is listed as Vulnerable (VU) based on the criteria of the International Union for Conservation of Nature, IUCN. Read More.

December 19, 2016

Previous studies on the genetic structure show that the individuals located close to each other tend to be related and usually there is greater genetic diversity within than there is among the life stages.

This variation might be the result of different ecological and genetic factors operating in the natural populations, as well as the varying spatial-temporal sampling and statistical methods used in the study.

In addition, the scale and magnitude of genetic structure may also differ significantly among the life stages, with seedlings often exhibiting greater structure within populations compared with the adults. Read more.

October 09, 2016

Although the number of studies on anthropogenic habitat fragmentation in plants is increasing, to date, there have been no reports on the genetic structure of populations that are naturally fragmented.

The perennial gymnosperm Podocarpus sellowii Klotzch is a typical tree species from a gallery forest in the rupestrian area in southeastern Brazil. Ten alloenzymatic loci were used to estimate the allelic frequency of 232 individuals distributed in eight subpopulations naturally divided by rock outcrops. Read more.

August 11, 2015

Assessment of genetic diversity of populations that occur in forest remnants and corridors of vegetation is crucial for developing efficient strategies for genetic conservation, and molecular markers can be used for this purpose.

In the present study, ISSR markers were used to analyze the genetic diversity of Myrcia splendens (Swartz) de Candolle on a fragment–corridor system. This knowledge will provide baseline information for the adequate management and the conservation of small forest fragments and vegetation corridors in the regional landscape. Read more.

January 29, 2015

We compared the evolutionary history of the tree Ficus bonijesulapensis, endemic to Brazilian seasonally dry tropical forests (SDTFs), with the two hypotheses about the historical biogeography of SDTFs in the region: retraction or expansion during the Holocene.

The low genetic diversity, unimodal mismatch distribution and unfavourable climatic conditions in the southern region suggest a recent southward expansion of the F. bonijesulapensis during the Holocene, supporting the hypothesis of the southward expansion of SDTFs during this period. Read more.

January 19, 2015

In Brazil, the Seasonally Dry Tropical Forests (SDTF) are found in the Caatinga and Cerrado Domains, and they are considered to be the remnants of vast semiarid vegetation. The SDTF grow on different types of soil, such as rocky outcrops that, because they hold species that are able to survive extreme climates, and in particular edaphic conditions, are considered peculiar ecosystems and centers of diversity.

Therefore, the conservation of these species in their natural habitat contributes to the maintenance of the long-term population viability and their genetic diversity. Read more.

December 31, 2014

Aspidosperma pyrifolium (Apocynaceae) and Caesalpinia pyramidalis (Fabaceae) share the same habitat in the Brazilian Caatinga domain.

In this paper, we investigate the intra and inter-species interactions between these two plants using spatial pattern analysis among cohorts. Using a bivariate analysis of the neighborhood density, we confirmed the significant coexistence between the two species. Read more.

August 21, 2014

Because of their interconnectedness, riparian forests play a central role in biogeographical and evolutionary shifts as they facilitate seed dispersal.

Calophyllum brasiliense (Clusiaceae), a Neotropical tree commonly known as “guanandi,” is widely distributed throughout Central and South America. In Brazil, the wide distribution ensures its presence in watersheds of several phytoecological regions.

The objective of this study was to assess the genetic variability in natural populations of C. brasiliense located along different rivers. Read more.

February 28, 2014

Inter simple sequence repeats (ISSRs) markers are a potential tool to be used in the phylogenetic reconstruction of closely related species.

The phylogenetic relationships between Cattleya granulosa, an endangered Brazilian orchid, and four other native Brazilian species (Brassavola tuberculata, Cattleya bicolor, Cattleya labiata and Cattleya schofieldiana) were analyzed for genetic diversity and differentiation. Read more.

December 28, 2012

Besides the quality of its wood, the extraction of the α-bisabolol oil from the candeia (Eremanthus erythropappus - Asteraceae) for pharmaceutical and cosmetic industries gives the species a high economic value.

We studied anthesis, flower morphology, stigmatic receptivity, pollen viability and floral visitors of candeia (Eremanthus erythropappus - Asteraceae).

We observed a large percentage of viable pollen (77.25%) and relatively scarce nectar availability for floral visitors (0.63 μL). The bees Apis mellifera and Trigona sp. were the most frequent visitors. The length of the bud, style and flowers varied significantly among plants. Read more.

April 22, 2012

We present a case study of the relationship between spatial genetic structure (SGS) and age structure in Protium spruceanum (Burseraceae), an insect-pollinated, mass-fruiting, and secondary bird-dispersed tree, as determined through variation in allozyme loci. 

The degree of SGS decreased across small- to large-diameter classes. We inferred that limited seed dispersal and subsequent density-dependent mortality from the family clusters are responsiblefor the observed changes in fine-scale SGS across different demographic classes. Read more.

February 25, 2011

Geonoma schottiana Mart. (Arecaceae) is an underbrush palm species found in high densities in tropical forests. It has a well defined supporting stalk, although it may shoot out to form a thicket structure, having a frequently twisted stipe, between 1.6 m and 6 m in length.

This species is known for its extended fruiting periods throughout virtually every month of the year, revealing its potential importance for the conservation of fruit eating birds.

We investigated the patterns of inter- and intrapopulation genetic diversity, in order to determine the spatial distribution of genotypes in two populations of G. schottiana. Read more.

October 22, 2010

Many members of the Burseraceae family, which are well-known sources of gums and resins, are dioecious and produce small flowers. Information on their reproductive biology however is available for only a few species of this family.

Protium spruceanum (Benth.) Engler, locally known as breu, is a large canopy tree (up to 20 m tall), found in the Amazon and Atlantic rainforests and on the cerrado riverbank woodland. We investigated the reproductive biology and phenology of P. spruceanum, and the effective pollinators were Apis mellifera and Trigona sp. (Hymenoptera, Apidae).

Pollen tubes of cross-pollinated flowers were observed entering the ovaries 48 h after pollination. The fruiting season is from October to March, with a peak in November, coinciding with the rainfall peak. Read more.

February 08, 2010

The spatial isolation and reduction of natural populations negatively affects the reproductive success of many tropical plants.

We investigated the occurrence of fine-scale genetic structure in a second-growth population of Euterpe edulis Mart., an insect pollinated and bird/mammal-dispersed native palm of the Brazilian Atlantic forest.

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We found a radial distribution of the density, suggesting dispersion distance from a single source. Moreover, the low density of maternal seed sources and, consequently, limited seed dispersal can explain the radial distribution. As a result, nonrandom spatial genetic patterns within a natural population of E. edulis were measured in this study. Read more about implications for conservation. Read more.

July 04, 2008

Tropical forests present very diverse terrestrial ecosystems, but much of this diversity is threatened by habitat destruction and extensive fragmentation of natural populations. Creation or preservation of landscape structures, such as vegetation corridors, has been indicated to minimize the effects of habitat fragmentation. Especially in the Neotropical region, little is known about corridor importance for plant species, and previous work on this topic was not focused on population genetic processes.

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The forest remnants in the state of Minas Gerais, Southeastern Brazil, are characterized by a hilly relief covered by vegetation mosaics formed by the contact between Atlantic seasonal forests, cerrado (woody savanna) and montane grasslands. In the vegetation corridors that connect small remnants of undisturbed primary forest in the Lavras landscape (Brazil), Protium spruceanum is a representative of a mass flowering insect-pollinated and bird-dispersed tree.

Allozyme variation was quantified from five forest remnants from secondary vegetation corridors linking them to generate information for genetic conservation. Evidence of recent bottlenecks by anthropogenic disturbance was detected in fragments, but the genetic differentiation among remnants was low, and vegetation corridors have genetic identity with the fragments. Thus, our results suggest that landscape management strategies should therefore consider both the creation of new vegetation corridors and the protection of extant ones. Read more.