Forecasting effects of climate changes on the population genetic structure of Anacardium occidentale in the Cerrado biome, Brazil.

There has been a continuous interest in understanding the patterns of genetic diversity in natural populations because of the role of intraspecific genetic diversity as the basis of all evolutionary change and thus, its potential effects on population persistence when facing environmental changes. Here, we provided the first description of genetic diversity distribution and population structure of Anacardium occidentale L. (cashew) from the Brazilian Cerrado, one of the most economically important tropical crops in the world. We applied Bayesian clustering approaches (STRUCTURE and POPS) that allow predicting the effects of future climatic changes on the population genetic structure of A. occidentale. We identified distinct genetic groups corresponding to the southwestern, central, and northern regions of the species' range. The characterized genetic clusters will disappear under future climate change scenarios, leading to a homogenization of genetic variability across the landscape. Our findings suggest a high likelihood for the loss of genetic diversity, which in turn will reduce the evolutionary potential of the species to cope with predicted future climatic changes. Results from this study may help develop management strategies to conserve the genetic diversity and structure of natural cashew populations.

Multi-Scale Landscape Influences on Genetic Diversity and Adaptive Traits in a Neotropical Savanna Tree.

Changes in landscape structure can affect essential population ecological features, such as dispersal and recruitment, and thus genetic processes. Here, we analyze the effects of landscape metrics on adaptive quantitative traits variation, evolutionary potential, and on neutral genetic diversity in populations of the Neotropical savanna tree Tabebuia aurea. Using a multi-scale approach, we sampled five landscapes with two sites of savanna in each. To obtain neutral genetic variation, we genotyped 60 adult individuals from each site using 10 microsatellite loci. We measured seed size and mass. Seeds were grown in nursery in completely randomized experimental design and 17 traits were measured in seedlings to obtain the average, additive genetic variance (V a ) and coefficient of variation (CV a %), which measures evolvability, for each trait. We found that habitat loss increased genetic diversity (He) and allelic richness (AR), and decreased genetic differentiation among populations (F ST ), most likely due to longer dispersal distance of pollen in landscapes with lower density of flowering individuals. Habitat amount positively influenced seed size. Seeds of T. aurea are wind-dispersed and larger seeds may be dispersed to short distance, increasing genetic differentiation and decreasing genetic diversity and allelic richness. Evolvability (CV a %) in root length decreased with habitat amount. Savanna trees have higher root than shoot growth rate in the initial stages, allowing seedlings to obtain water from water tables. Landscapes with lower habitat amount may be more stressful for plant species, due to the lower plant density, edge effects and the negative impacts of agroecosystems. In these landscapes, larger roots may provide higher ability to obtain water, increasing survival and avoiding dying back because of fire. Despite the very recent agriculture expansion in Central Brazil, landscape changes are affecting neutral and adaptive variation in T. aurea. Several populations have low additive genetic variation for some traits and thus, may have limited evolvability, which may jeopardize species long-term persistence. The effect of habitat loss on highly variable neutral loci may only be detected after a certain threshold of population size is attained, that could become dangerously small masking important losses of heterozygosity endangering species conservation.

Agricultural Landscape Heterogeneity Matter: Responses of Neutral Genetic Diversity and Adaptive Traits in a Neotropical Savanna Tree.

Plants are one of the most vulnerable groups to fragmentation and habitat loss, that may affect community richness, abundance, functional traits, and genetic diversity. Here, we address the effects of landscape features on adaptive quantitative traits and evolutionary potential, and on neutral genetic diversity in populations of the Neotropical savanna tree Caryocar brasiliense. We sampled adults and juveniles in 10 savanna remnants within five landscapes. To obtain neutral genetic variation, we genotyped all individuals from each site using nine microsatellite loci. For adaptive traits we measured seed size and mass and grown seeds in nursery in completely randomized experimental design. We obtained mean, additive genetic variance (V a ) and coefficient of variation (CV a %), which measures evolvability, for 17 traits in seedlings. We found that landscapes with higher compositional heterogeneity (SHDI) had lower evolutionary potential (CV a %) in leaf length (LL) and lower aboveground dry mass (ADM) genetic differentiation (Q ST ). We also found that landscapes with higher SHDI had higher genetic diversity (He) and allelic richness (AR) in adults, and lower genetic differentiation (F ST ). In juveniles, SHDI was also positively related to AR. These results are most likely due to longer dispersal distance of pollen in landscapes with lower density of flowering individuals. Agricultural landscapes with low quality mosaic may be more stressful for plant species, due to the lower habitat cover (%), higher cover of monocropping (%) and other land covers, and edge effects. However, in landscapes with higher SHDI with high quality mosaic, forest nearby savanna habitat and the other environments may facilitate the movement or provide additional habitat and resources for seed disperses and pollinators, increasing gene flow and genetic diversity. Finally, despite the very recent agriculture expansion in Central Brazil, we found no time lag in response to habitat loss, because both adults and juveniles were affected by landscape changes.

Genetic variability and effective population size in Hymenaea stigonocarpa (Fabaceae) germplasm collection: tools for breeding programs and genetic conservation.

The conservation of plant genetic resources is essential for breeding programs. Regarding the native species of the Brazilian Cerrado biome, many studies have demonstrated their high potential for use in both medicines and foods. Hymenaea stigonocarpa, a tree with wide occurrence in the Cerrado, has economic importance, and due its extractive use, the establishment of a breeding program is relevant for sustainable use and conservation. Thus, the first germplasm collection of the species was installed at the Federal University of Goiás (UFG). To know the magnitude of genetic variability and how it was distributed in the collection, 353 individuals, distributed in 119 families from 24 subpopulations collected in the Cerrado biome, were genotyped using capillary electrophoresis. Nine pairs of microsatellite markers were genotyped. The UFG germplasm collection showed a high level of genetic diversity (mean [Formula: see text] = 0.554) at the evaluated loci. By Analysis of Molecular Variance (AMOVA), a significant genetic structure was detected (θP = 0.152, p < 0.01), which was expected since the subpopulations that originated the germplasm collection were collected in geographically distant locations. In addition, the germplasm collection had a population effective size of 54.9 and presented an allelic representation of 79.89% compared to 32 natural subpopulations. These results demonstrate that the germplasm collection preserves a high genetic diversity of H. stigonocarpa with a population effective size considered sufficient for the conduction of a breeding program.

Caracterização física e físico-química de frutos de araticum (Annona crassiflora Mart. ) / Physical and physical and chemical characterization of araticum fruits (Annona crassiflora Mart. )

Este trabalho objetivou caracterizar física e quimicamente frutos de araticum coletados de populações naturais de plantas localizadas em cinco áreas de Cerrado do estado de Goiás. O trabalho foi realizado na Escola de Agronomia e Engenharia de Alimentos da Universidade Federal de Goiás. Os frutos maduros foram avaliados individualmente, por área e por planta. Determinaram-se: massas do fruto, da polpa e da casca, diâmetro e altura do fruto, número total de sementes e de sementes defeituosas por fruto, massa das sementes, cores do fruto, da casca e da polpa, textura da casca e teor de sólidos solúveis totais. As características físicas mostraram variação significativa entre frutos de plantas das diferentes áreas. A massa média do fruto foi de 872,06 g. A polpa, parte de importância econômica, representou cerca de 47% dessa massa, cuja variação por região foi de 44% a 49%. O número de sementes foi elevado, em média 108, representando 15,8% da massa do fruto. Há tendência para a cor marrom da casca, assim como para a cor amarelada ou creme da polpa. Observou-se uma variação de textura da casca, desde lisa até rugosa. Do total de 219 frutos avaliados, 15,5% apresentaram o orifício de saída de Bephratelloides pomorum. Houve diferenças significativas entre áreas e entre plantas dentro de áreas para todas as variáveis físicas. A massa média dos frutos de araticum foi de 872,06 g com rendimento médio de polpa, casca e sementes de: 46,8%, 37,4% e 15,8%, respectivamente.

This work objectified to characterize physics chemically and collected fruits of araticum of natural populations of plants located in five areas of Cerrado of the state of Goiás. The work was carried through in the "Escola de Agronomia e Engenharia de Alimentos, Universidade Federal de Goiás". The mature fruits had been evaluated individually, for area and plant. They had been determined: masses of the fruit, the pulp and the rind, diameter and height of the fruit, total number of seeds and defective seeds for fruit, mass of the seeds, colors of the fruit, the rind and the pulp, texture of the rind and total soluble solids. The physical characteristics had shown significant variation between fruits of plants of the different areas. The average mass of the fruit was of 872,06 g. The pulp, part of economic importance, represented about 47% of this mass, whose variation for region was of 44% 49%. The number of seeds was raised, on average 108, representing 15.8% of the mass of the fruit. It has trend for the brown color of the rind, as well as for the yellowish color or cream of the pulp. A variation of texture of the rind was observed, since smooth until rough. Of the total 219 of evaluated fruits, 15.5% had presented the orifice of exit of Bephratelloides pomorum. It inside had significant differences between areas and plants of areas for all the variable physicist. The mass average of the 872,06 fruits of araticum was of g with average income of pulp, rind and seeds of: 46.8%, 37.4% and 15.8%, respectively.

Germinação de sementes e emergência de plântulas de araticum oriundos do cerrado de Goiás / Seed germination and seedling emergence of araticum from cerrado of Goiás state

O araticum (Annona crassiflora M.) é uma espécie frutífera da família Annonaceae, nativa da região dos cerrados, com ocorrência em todo o Estado de Goiás. O objetivo deste trabalho foi estudar a germinação de sementes de frutos de araticum coletados de populações naturais de plantas localizadas em cinco áreas de Cerrado do Estado de Goiás, tratadas com ácido giberélico (GA3). Determinou-se a velocidade de emergência a cada três dias e o percentual de germinação de sementes, de frutos de 75 plantas. O delineamento utilizado foi o de blocos casualizados, com quatro blocos e 75 tratamentos. Cada parcela foi composta por 50 sementes de uma mesma planta, totalizando 15.000 sementes. Os dados foram submetidos à análise de variância e aplicando-se o teste F. Houve germinação da maioria das sementes das plantas de cada área, mostrando que, independentemente do vigor, a dosagem utilizada de ácido giberélico foi adequada. Em média a percentagem de germinação variou de 12,81% em Vila Propicio a 28,81% em Campos Belos. Na planta 10 de Campos Belos observou-se a maior média para germinação (66%) e a menor média de dias necessários para a emergência (49 dias). As sementes provenientes de frutos de araticum das cinco áreas de Cerrado em estudo, apresentam diferenças na percentagem de germinação e na velocidade de emergêngia. As diferenças de germinação ocorrem entre plantas na área e entre áreas.

Araticum (Annona crassiflora M.) is a species of native fruit of the Annonaceas family which grows in the whole State of Goiás, Brazil. The objective of this work was to evaluate the germination of araticum fruits seeds collected of natural populations of plants located in five areas of Cerrado of the State of Goiás, treated with gibberellic acid (GA3). It was determined speed of emergency to each three days and the germination percentage of seeds, fruits of 75 plants. The used delineation was of randomized blocks, with four blocks and 75 treatments. Each parcel was composed for 50 seeds of one same plant, totalizing 15.000 seeds. The data had been submitted to the variance analysis and applying test F. It had germination of the majority of the seeds of the plants of each area, showing that, independently of the vigor, the used dosage of gibberellic acid was adjusted. On average the germination percentage varied of 12.81% in Vila Propicio 28.81% in Campos Belos. In plant 10 of Campos Belos observed it bigger average for germination (66%) and the average minor of necessary days for the emergency (49 days). The seeds proceeding from of araticum fruits of the five areas of Cerrado in study, present differences in the germination percentage and the speed of emergency. The germination differences occur between plants in the area and areas.

Development of microsatellite markers for the neotropical tree species Dipteryx alata (Fabaceae).

PREMISE OF THE STUDY: Microsatellite markers were developed for the population genetic analyses of the neotropical tree Dipteryx alata (Fabaceae). METHODS AND RESULTS: Microsatellites were developed from a genomic shotgun library. Polymorphism at each microsatellite loci was analyzed based on 94 individuals from three populations. Eight loci amplified successfully and presented one to 10 alleles, and expected heterozygosities ranged from 0.097 to 0.862. Four loci also amplified in Pterodon emarginatus and presented similar polymorphism. CONCLUSION: The eight microsatellite primer pairs are potentially suitable for population genetic studies and successfully amplified in another Fabaceae species.

Genetic structure of mangaba (Hancornia speciosa Gomes) populations in the cerrado region of central Brazil / Estrutura genética de subpopulações de mangabeira (Hancornia speciosa Gomes) no cerrado do Brasil central

Mangaba tree (Hancornia speciosa Gomes) is a fruit species with great potential for commercial exploitation, found in most regions of Brazil and highly frequent in the Cerrado biome. Information on the genetic variability in this biome is scarce. This study aimed at characterizing the genetic structure of eight populations found in the states of Goiás, Bahia and Minas Gerais by using RAPD markers. Genetic variability was assessed by the analysis of variance on molecular data. A significant proportion of genetic variance was found among populations, corresponding to 19.6 % of the total variation. The correlation between the matrices of geographic and genetic distances was not significant, indicating that there is no spatial structure of the genetic variability among the populations, for the RAPD marker loci used here. The high variability suggests that a strategy for in situ, as well as ex situ conservation, must be based on sampling a large number of local populations.

A mangabeira (Hancornia speciosa Gomes) é uma espécie frutífera com grande potencial para exploração econômica, encontrada em várias regiões do Brasil, sendo freqüente no bioma Cerrado. Informações sobre a variabilidade genética das populações existentes neste bioma são escassas. Este estudo teve como objetivo caracterizar a estrutura genética de oito populações situadas nos Estados de Goiás, Bahia e Minas Gerais por meio de marcadores RAPD. A estrutura da variabilidade genética foi avaliada utilizando-se a análise de variância de dados moleculares. Uma proporção significativa da variância genética foi encontrada entre populações, correspondendo a 19,6 % da variação total. A correlação entre as matrizes de distâncias geográficas e genéticas não foi significativa, indicando que não existe estruturação espacial da variabilidade genética entre populações, para os locos marcadores RAPD utilizados. A alta variabilidade sugere que estratégias para conservação in situ, bem como ex situ, devem ser baseadas em amostragem de um grande número de populações locais.

Correlação entre floração, frutificação e variáveis ambientais em Solanum lycocarpum. A. St. Hil, Solanaceae / Correlation between flowering, fructification and environmental variables in Solanum lycocarpum A. St.-Hil, Solanaceae

A lobeira (S. lycocarpum) é uma espécie típica e abundante do Cerrado, que ocupa principalmente ambientes antropizados. Possui características interessantes do ponto de vista da biologia reprodutiva, que provavelmente estão favorecendo a ampla ocupação pela espécie. Tendo em vista que a planta floresce e frutifica durante todo o ano, o presente estudo teve por objetivo verificar se existe correlação entre floração, frutificação e variáveis ambientais (temperatura, umidade e precipitação), como suporte para estudos futuros referentes à biologia reprodutiva e ecologia de espécies de plantas do Cerrado. Foi escolhida uma população de lobeira situada no município de Morrinhos, Sul do estado de Goiás, composta de 34 plantas em fase reprodutiva. Todas as plantas foram georreferenciados com um aparelho GPS. Foram feitas observações mensais durante 13 meses (junho de 2005 a julho de 2006) e quantificados flores abertas e frutos produzidos nos intervalos entre observações. Pode-se inferir alta conversão de flores hermafroditas em frutos. Por meio da correlação de Spearman, pode-se constatar correlação positiva entre floração e precipitação e umidade, o mesmo, aparentemente, não ocorre para frutificação.

Solanum lycocarpum (lobeira) is a typical and abundant species of brazilian Cerrado, which occupies mainly surrounding disturbed areas. It has interesting characteristics from the point of view of reproductive biology, that probably are favoring the large occupation of habitats by the species. Based on the fact that the species produces flowers and fruit during all the year, the present study had the purpose to verify the association between flower and fruit production with environmental variables (temperature, relative humidity and precipitation), aiming to support future studies referring to reproductive biology and ecology of plant species from Cerrado biome. A population of S. lycocarpum composed of 34 plants in reproductive phase, situated in Morrinhos, south of the State of Goiás, Brazil, , was evaluated. All the plants were geographically referenced with a GPS receptor. Observations were made monthly during 13 months (June, 2005 to July, 2006) quantifying open flowers and fruits produced in the intervals between the observations. It was possible suggest high conversion of flowers in fruits. The Spearman rank correlation showed positive correlation of flower number with precipitation and relative humidity. Fruit number was not correlated with the environmental variables.

Landscape conservation genetics of Dipteryx alata ("baru" tree: Fabaceae) from Cerrado region of central Brazil.

In this paper random amplified polymorphic DNA (RAPD) was used to evaluate the degree of among-population differentiation and associated spatial patterns of genetic divergence for Dipteryx alata Vogel populations from Cerrado region of central Brazil, furnishing support for future programs of conservation of this species. We analyzed patterns of genetic and spatial population structure using 45 RAPD loci scored for 309 trees, sampled from five different regions with two populations each. Genetic structure analysis suggested that panmixia null hypothesis can be rejected, with significant among-population components of 15%. Hierarchical partition by Analysis of Molecular Variance (AMOVA) shows that 5% of genetic variation is within regions, whereas 10% of variation is among regions, and these results were confirmed by a Bayesian analyses on HICKORY. The Mantel correlogram revealed that this divergence is spatially structured, so that local populations situated at short geographic distances could not be considered independent units for conservation and management. However, genetic discontinuities among populations were found in the northwest and southeast parts of the study area, corresponding to regions of recent socio-economic expansion and high population density, respectively. Taking both geographic distances and genetic discontinuities into account it is possible to establish a group of population to be conserved, covering most of D. alata geographic distribution and congruent with previously established priority areas for conservation in the Cerrado region.

Genetic structure of natural Eugenia dysenterica DC (Myrtaceae) populations in northeastern Goiás, Brazil, accessed by morphological traits and RAPD markers

The Brazilian Cerrado (Savannah) is a biome with great biodiversity. Many of the species found in this biome have unlimited economic potential and are used by the local population for various purposes. With the opening of the agricultural frontiers in this region, much of the native flora has been replaced by extensive areas of monocultures. Thirteen populations of the Eugenia dysenterica DC species were sampled in the northeast of the state of Goiás, Brazil, to analyze their genetic structure. Morphological traits were measured for all the progeny obtained and some of them were analyzed by using RAPD markers. The natural populations of the species showed high levels of variability for the morphological traits. The phenotypic, genotypic and genetic variabilities as structured in these populations were highly significant among populations, although most of the variability was detected within populations. The phenotypic and genetic variabilities were structured spatially as shown by the positive and highly significant correlation coefficients between the phenotypic and genetic distance matrixes and the geographic distance matrix. The ideal conservation strategy for the species in the region requires sampling of a high number of individuals of each population and also a significant number of populations to ensure suitable effective population sizes.

Prediction of hybrid means from a partial circulant diallel table using the ordinary least square and the mixed model methods

By definition, the genetic effects obtained from a circulant diallel table are random. However, because of the methods of analysis, those effects have been considered as fixed. Two different statistical approaches were applied. One assumed the model to be fixed and obtained solutions through the ordinary least square (OLS) method. The other assumed a mixed model and estimated the fixed effects (BLUE) by generalized least squares (GLS) and the best linear unbiased predictor (BLUP) of the random effects. The goal of this study was to evaluate the consequences when considering these effects as fixed or random, using the coefficient of correlation between the responses of observed and non-observed hybrids. Crossings were made between S1 inbred lines from two maize populations developed at Universidade Federal de Goiás, the UFG-Samambaia "Dent" and UFG-Samambaia "Flint". A circulant inter-group design was applied, and there were five (s = 5) crossings for each parent. The predictions were made using a reduced model. Diallels with different sizes of s (from 2 to 5) were simulated, and the coefficients of correlation were obtained using two different approaches for each size of s. In the first approach, the observed hybrids were included in both the estimation of the genetic parameters and the coefficient of correlation, while in the second a cross-validation process was employed. In this process, the set of hybrids was divided in two groups: one group, comprising 75 percent of the original group, to estimate the genetic parameters, and a second one, consisting of the remaining 25 percent, to validate the predictions. In all cases, a bootstrap process with 200 resamplings was used to generate the empirical distribution of the correlation coefficient. This coefficient showed a decrease as the value of s decreased. The cross-validation method allowed to estimate the bias magnitude in evaluating the correlation coefficient using the same hybrids, to predict the genetic parameters and the correlation evaluation. The bias was shown to be greater when the OLS method was used...

Genetic structure and gene flow in Eugenia dysenterica DC in the Brazilian Cerrado utilizing SSR markers

The ''cagaita tree'' (Eugenia dysenterica) is a plant found widespread in the Brazilian Cerrado. Its fruit is used for popular consumption and for industrial purposes. This study opens a new perspective for the generation of population genetic data and parameters estimates for devising sound collection and conservation procedures for Eugenia dysenterica. A battery of 356 primer pairs developed for Eucalyptus spp. was tested on the ''cagaita tree''. Only 10 primer pairs were found to be transferable between the two species. Using a polyacrilamide gel, an average of 10.4 alleles per locus was detected, in a sample of 116 individuals from 10 natural ''cagaita tree'' populations. Seven polymorphic loci allowed estimation of genetic parameters, including expected average heterozygosity He = 0,442, among population diversity, R ST = 0,268 and gene flow Nm = 0,680. Results indicated a potential of SSR locus transferability developed for Eucalyptus to other species of different genera, such as in the case of the ''cagaita tree''. The high genetic diversity among populations detected with SSR markers indicated that these markers are highly sensitive to detect population structure. Estimated Nm values and the existence of private alleles indicated reduced gene flow and consequently possible damage to the metapopulation structure.