Estrutura genética e sistema de acasalamento de Piper hispidinervum

Long pepper (Piper hispidinervum C. DC.) is a small tree with high commercial value found in areas under anthropic influence in the State of Acre, Brazil. The genetic structure and mating system of P. hispidinervum were evaluated using RAPD markers. The genetic diversity within and between natural populations were evaluated in 13 populations in the Basin Acre River - Western Brazilian Amazon. Twenty five open-pollinating families in a population located in Assis Brasil were evaluated to estimate the preferential crossing rate. Genetic diversity was observed, revealing that this species is spatially structured according to a pattern of isolation by distance. Most of the genetic variability was found within populations, and the variation between populations was also high (θP = 0.28). Two distinct groups were formed, based on genetic distances (φST), representing the Upper Acre and Lower Acre watersheds. By AMOVA, 20.61% of the total variability occurs between those two watershed regions. The multilocus crossing rate was estimated at 1.033, the estimate of the inbreeding coefficient (F) did not vary from zero, and the crosses preferentially occurred between unrelated individuals.A pimenta-longa (Piper hispidinervum C. DC.) arbusto encontrado em áreas antropizadas no Estado do Acre, possui expressiva importância econômica decorrente da presença de safrol em seu óleo essencial. O objetivo deste trabalho foi avaliar a estrutura genética e o sistema de acasalamento dessa espécie, utilizando marcadores RAPD (polimorfismo de DNA amplificado ao acaso). A diversidade genética entre e dentro de populações naturais foi avaliada em 13 populações do Vale do Rio Acre, distribuídas nas Regiões do Baixo e Alto Acre. A taxa preferencial de cruzamento foi estimada em 25 famílias de polinização livre de uma população do Município de Assis Brasil, Acre. A espécie apresentou diversidade genética estruturada no espaço segundo um padrão de isolamento por distância. A maior parte da variabilidade genética foi encontrada dentro das populações, porém a diferenciação entre populações, como um todo, foi alta (θP = 0,28). O agrupamento das populações, pela distância genética (φST) entre elas, mostrou dois grupos distintos, os quais representam as regiões do Alto Acre e Baixo Acre. A AMOVA mostrou que 20,61% da variabilidade total está entre essas duas regiões. A taxa de cruzamento multilocos foi estimada em 1,033, evidenciando que a espécie é alógama. A estimativa do coeficiente de endogamia F não diferiu de zero e os cruzamentos ocorreram preferencialmente entre indivíduos não-aparentados

Coeficiente de repetibilidade para produção de frutos e seleção de matrizes de Bertholletia excelsa (Bonpl.) em castanhais nativos do estado do Acre

More than 95% of Brazil nut production in Brazil comes from the extractive collection, with few plantations for commercial production. To contribute with Brazil nut tree genetic improvement, this study aimed to estimate number of fruits (NFP) repeatability coefficients; determine the appropriate number of measurements for efficient selection; and select Brazil nut promising trees from two Brazil nut stands in the state of Acre. The study was carried out in permanent plots in Filipinas (Resex Chico Mendes, Epitaciolândia-AC) and Cachoeira (PAE Chico Mendes, Xapuri-AC). The number of fruits per plant (NFP) was estimated at 140 Brazil nut trees from 2002 to 2014 (13 years), while in Cachoeira there were 175 Brazil nut trees from 2009 to 2014 (six years). Genetic-statistical analyzes were performed based on the mixed model methodology, using the Selegen-REML/BLUP Model 63. Twenty matrices were selected, 08 in Filipinas and 12 in Cachoeira. In both Brazil nuts stands, the permanent phenotypic variance (Vfp) represented the largest percentage of the individual phenotypic variance (Vf). The repeatability coefficient was considered moderate for Cachoeira and high for Filipinas. Considering a 90% coefficient of determination, it would take seven years of NFP assessment for Cachoeira and six years for Filipinas. The existing database for the Brazil nut production is sufficient to make selection for matrices with high fruit production. Based on the estimated values we expect the new population to have an average yield of 465.3 fruits.arv-1, indicating a gain in fruit production of about 2.4 times for Cachoeira and 4.2 for Filipinas.Mais de 95% da produção brasileira de castanha-da-amazônia é oriunda da coleta extrativista sendo poucos os plantios para produção comercial. Buscando contribuir com informações básicas para o melhoramento genético da castanheira, este estudo teve por objetivos: estimar os coeficientes de repetibilidade para o número de frutos (NFP); determinar o número adequado de medições para uma eficiente seleção de matrizes; e, selecionar castanheiras promissoras em dois castanhais nativos, no Estado do Acre. O estudo foi realizado em parcelas permanentes no Filipinas (Resex Chico Mendes, Epitaciolândia-AC) e Cachoeira (PAE Chico Mendes, Xapuri-AC). O número de frutos por planta (NFP) foi avaliado em 140 castanheiras no Filipinas, no período de 2002 a 2014 (13 anos), enquanto no Cachoeira foram 175 castanheiras de 2009 a 2014 (seis anos). As análises genético-estatísticas foram feitas com base na metodologia de modelos mistos, utilizando-se o software Selegen-REML/BLUP, Modelo 63. Foram selecionadas 20 matrizes, sendo 08 no Filipinas e 12 no Cachoeira. Em ambos os castanhais, a variância fenotípica permanente (Vfp) representou a maior porcentagem da variância fenotípica individual (Vf). O coeficiente de repetibilidade foi considerado moderado para o Cachoeira e alto para o Filipinas. Considerando um coeficiente de determinação de 90%, seriam necessários sete anos de avaliação do NFP para o Cachoeira e seis anos para o Filipinas. O banco de dados existentes para a produção de frutos das castanheiras é suficiente para se realizar a seleção de matrizes com alta produção de frutos. Com base nos valores estimados espera-se que a nova população apresente uma produção média de 465,3 frutos.arv-1, indicando um ganho na produção de frutos cerca de 2,4 vezes para o Cachoeira e 4,2 para o Filipinas

Coeficiente de repetibilidade para produção de frutos e seleção de matrizes de Bertholletia excelsa (Bonpl.) em castanhais nativos do estado do Acre

More than 95% of Brazil nut production in Brazil comes from the extractive collection, with few plantations for commercial production. To contribute with Brazil nut tree genetic improvement, this study aimed to estimate number of fruits (NFP) repeatability coefficients; determine the appropriate number of measurements for efficient selection; and select Brazil nut promising trees from two Brazil nut stands in the state of Acre. The study was carried out in permanent plots in Filipinas (Resex Chico Mendes, Epitaciolândia-AC) and Cachoeira (PAE Chico Mendes, Xapuri-AC). The number of fruits per plant (NFP) was estimated at 140 Brazil nut trees from 2002 to 2014 (13 years), while in Cachoeira there were 175 Brazil nut trees from 2009 to 2014 (six years). Genetic-statistical analyzes were performed based on the mixed model methodology, using the Selegen-REML/BLUP Model 63. Twenty matrices were selected, 08 in Filipinas and 12 in Cachoeira. In both Brazil nuts stands, the permanent phenotypic variance (Vfp) represented the largest percentage of the individual phenotypic variance (Vf). The repeatability coefficient was considered moderate for Cachoeira and high for Filipinas. Considering a 90% coefficient of determination, it would take seven years of NFP assessment for Cachoeira and six years for Filipinas. The existing database for the Brazil nut production is sufficient to make selection for matrices with high fruit production. Based on the estimated values we expect the new population to have an average yield of 465.3 fruits.arv-1, indicating a gain in fruit production of about 2.4 times for Cachoeira and 4.2 for Filipinas.Mais de 95% da produção brasileira de castanha-da-amazônia é oriunda da coleta extrativista sendo poucos os plantios para produção comercial. Buscando contribuir com informações básicas para o melhoramento genético da castanheira, este estudo teve por objetivos: estimar os coeficientes de repetibilidade para o número de frutos (NFP); determinar o número adequado de medições para uma eficiente seleção de matrizes; e, selecionar castanheiras promissoras em dois castanhais nativos, no Estado do Acre. O estudo foi realizado em parcelas permanentes no Filipinas (Resex Chico Mendes, Epitaciolândia-AC) e Cachoeira (PAE Chico Mendes, Xapuri-AC). O número de frutos por planta (NFP) foi avaliado em 140 castanheiras no Filipinas, no período de 2002 a 2014 (13 anos), enquanto no Cachoeira foram 175 castanheiras de 2009 a 2014 (seis anos). As análises genético-estatísticas foram feitas com base na metodologia de modelos mistos, utilizando-se o software Selegen-REML/BLUP, Modelo 63. Foram selecionadas 20 matrizes, sendo 08 no Filipinas e 12 no Cachoeira. Em ambos os castanhais, a variância fenotípica permanente (Vfp) representou a maior porcentagem da variância fenotípica individual (Vf). O coeficiente de repetibilidade foi considerado moderado para o Cachoeira e alto para o Filipinas. Considerando um coeficiente de determinação de 90%, seriam necessários sete anos de avaliação do NFP para o Cachoeira e seis anos para o Filipinas. O banco de dados existentes para a produção de frutos das castanheiras é suficiente para se realizar a seleção de matrizes com alta produção de frutos. Com base nos valores estimados espera-se que a nova população apresente uma produção média de 465,3 frutos.arv-1, indicando um ganho na produção de frutos cerca de 2,4 vezes para o Cachoeira e 4,2 para o Filipinas

Genetic diversity structure of crabwood in Baixo Acre, Brazil

O objetivo deste trabalho foi avaliar a diversidade genética em duas populações de Carapa guianensis Aubl. (andiroba), no Estado do Acre, e comparar os parâmetros de diversidade com os observados em outras populações da espécie (no Brasil: Flona Tapajós, PA, Porto Acre, AC; e na Costa Rica). Foram avaliados 77 indivíduos adultos com sete locos polimórficos de microssatélites. Observaram-se 51 alelos nas duas populações, em que o número efetivo de alelos por loco (Âe = 3,2) foi inferior ao número médio de alelos por loco ( = 7,3), o que indica elevado número de alelos com baixa freqüência. Os valores estimados de f^ não diferiram de zero, o que mostra que não ocorre endogamia nas populações. A taxa de cruzamento aparente foi alta (t^a = 1,11 na população Porto Acre, e t^a = 0,88 na de Rio Branco), resultado indicador de que a espécie se reproduz por alogamia. Foi observado, por meio das estimativas de  , Ĥe (diversidade gênica) e N^e (número efetivo populacional) que as populações de andiroba, comparadas neste trabalho, tiveram padrões de diversidade semelhantes, porém, proporções de alelos raros diferentes.The objective of this work was to evaluate the genetic diversity of two Carapa guianensis Aubl. (crabwood) populations, in the State of Acre, Brazil, and to compare the diversity estimations with those obtained in other populations of the species (in Brazil: Flona Tapajós, PA, Porto Acre, AC; and in Costa Rica). Seventy-seven individuals were assessed using seven polymorphic microsatellite loci. Fifty-one alleles were observed in the two populations, in which the effective number of alleles per locus (Âe = 3.2) was lower than the average number of alleles per locus ( = 7.3), which indicates a high number of low frequency alleles. The estimated f^ values did not differ from zero, showing that inbreeding does not occur in these populations. The apparent outcrossing rate was high for both populations (t^a = 1.11 in Porto Acre population, and t^a = 0.88 in Rio Branco), indicating that this species reproduces by outcrossing. Comparing the estimates of A^e, Ĥe (gene diversity) and N^e (effective population number), it was observed that the general patterns of genetic diversity were similar. However, the number of rare alleles differ between populations

Preservation and maceration of amazon açai leaflet tissue to obtain genomic DNA

The objective of this study was to test the efficiency of preservation and maceration methods for Euterpe precatoria leaflet tissue to obtain genomic DNA for molecular studies. The leaflets of E. precatoria were collected in an experimental field at Embrapa Acre, Brazil. The study was conducted in a completely randomized design with 10 replicates, in a 12 × 2 factorial structure, with 12 storage treatments (fresh; lyophiliser 3 days; refrigerator 3, 5, and 7 days; silica gel 7, 10, 20, and 30 days; and transport buffer 3, 5, and 7 days) and two leaf tissue maceration methods (liquid nitrogen and the TissueLyser®). Statistically significant differences in the obtained DNA concentration were found between the maceration and storage treatments. The TissueLyser® macerator produced higher DNA concentrations when compared to liquid nitrogen. For the storage treatments, five groups were formed based on DNA concentration when macerated with the TissueLyser® and two groups when macerated with liquid nitrogen. The DNA concentrations ranged from 285.00 ng/µL (7 days in transport buffer) to 702.00 ng/µL (30 days in silica gel) when the leaflets were macerated with liquid nitrogen, and from 572.73 ng/µL (30 days in silica gel) to 2,850.00 ng/µL (3 days in lyophiliser) using the TissueLyser® macerator. The DNA purity (A260/A280 nm) varied from 1.30 to 1.70 when the leaflets were macerated with liquid nitrogen and from 1.30 to 1.90 with the TissueLyser® macerator. Despite the variations in leaf tissue preservation and DNA concentration, all treatments were effective for DNA isolation and it was possible to amplify genomic regions of microsatellite markers by PCR. It was concluded that leaflets of E. precatoria stored in a lyophiliser and processed with an automatic macerator resulted in satisfactory DNA for molecular studies

Natural variation of arsenic fractions in soils of the Brazilian Amazon

Arsenic (As) in native soils of the Amazon rainforest is a concern due to its likely origin from the Andean rivers, which transport loads of sediments containing substantial amounts of trace elements coming from the cordilleras. Yet, unveiling soil As baseline concentrations in the Amazon basin is still a need because most studies in Brazil have been performed in areas with predominantly high concentrations and cannot express a real baseline value for the region. In this study, 414 soil samples (0–20, 20–40 and 40–60 cm layers) were collected from different sites throughout the Amazon basin - including native Amazon rainforest and minimally disturbed areas - and used to determine total and extractable (soluble + available) As concentrations along with relevant soil physicochemical properties. Descriptive statistics of the data was performed and Pearson correlation supported by a Principal Component Analysis (PCA) provided an improved understanding of where and how As concentrations are influenced by soil attributes. Total As concentration ranged from 0.98 to 41.71 mg kg−1 with values usually increasing from the topsoil (0–20 cm) to the deepest layer (40–60 cm) in all sites studied. Considering the proportional contribution given by each fraction (soluble and available) on extractable As concentration, it is noticeable that KH2PO4-extractable As represents the most important fraction, with >70% of the As extracted on average in all the sites studied. Still, the extractable fractions (soluble + available) correspond to ~0.24% of the total As, on average. Total, available, and soluble As fractions were strongly and positively correlated with soil Al3+. The PCA indicated that soil pH in combination with CEC might be the key factors controlling soil As concentrations and the occurrence of each arsenic fraction in the soil layers

MASTREE+: Time-series of plant reproductive effort from six continents.

Significant gaps remain in understanding the response of plant reproduction to environmental change. This is partly because measuring reproduction in long-lived plants requires direct observation over many years and such datasets have rarely been made publicly available. Here we introduce MASTREE+, a data set that collates reproductive time-series data from across the globe and makes these data freely available to the community. MASTREE+ includes 73,828 georeferenced observations of annual reproduction (e.g. seed and fruit counts) in perennial plant populations worldwide. These observations consist of 5971 population-level time-series from 974 species in 66 countries. The mean and median time-series length is 12.4 and 10 years respectively, and the data set includes 1122 series that extend over at least two decades (≥20 years of observations). For a subset of well-studied species, MASTREE+ includes extensive replication of time-series across geographical and climatic gradients. Here we describe the open-access data set, available as a.csv file, and we introduce an associated web-based app for data exploration. MASTREE+ will provide the basis for improved understanding of the response of long-lived plant reproduction to environmental change. Additionally, MASTREE+ will enable investigation of the ecology and evolution of reproductive strategies in perennial plants, and the role of plant reproduction as a driver of ecosystem dynamics

Movimentação de cátions em amostras de um Latossolo Vermelho-Amarelo incubadas com duas fontes de cálcio

Este artículo presenta una revisión de los desarrollos más notables en la tecnología de reconocimiento del iris humano, así como nuevas aproximaciones que buscan una mayor robustez del proceso con diferentes optimizaciones a través de técnicas computacionales y/o matemáticas. Se pretende brindar una visión completa pero sucinta de los avances logrados, así como futuros desarrollos que pueden aportar a la consolidación de esta tecnología biométrica