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Chromosomal patterns are valuable tools in evolutionary approaches. Despite the remarkable expansion of fish cytogenetic data, they are still highly deficient concerning deep oceanic species, including the Gempylidae snake mackerels. The snake mackerels are important commercial species composed by meso- and bento-pelagic predators with very limited information available about their lifestyle and genetics patterns. This study presents the first chromosomal data of two circumglobal species of this family, Ruvettus pretiosus and Promethichthys prometheus, from the São Pedro and São Paulo Archipelago. Conventional analyses, chromosomal staining with base-specific fluorochromes, and fluorescence in situ hybridization (FISH) for mapping of repetitive DNA classes were used. Both species have 2n = 48 chromosomes, but they highly differ regarding the karyotype formula (FN = 50 and FN = 84). The 18S rDNA/Ag-NOR and the 5S rDNA sites have a syntenic bi-telomeric array in R. pretiosus, but an independent distribution in P. prometheus. The transposable elements are dispersed, while the microsatellites are also clustered in the centromeric and terminal regions of some chromosomes. It is noteworthy that despite the 2n conservation, a marked macro and microstructural diversifications, mainly mediated by pericentric inversions, differentiates the karyotypes of the species, pointing to a particular chromosomal trajectory of the gempylids among marine fish. [ABSTRACT FROM AUTHOR]

The biogeographic history of a species results from responses to past and current processes, and understanding those responses at both temporal scales is essential. We explored phylogeographic and current genetic variation structure in Ctenomys flamarioni —a subterranean rodent that inhabits a small region of the coastal plain of Brazil—and contrasted the roles of "present-day niche suitability" versus "historical climate stability" to understand current and past intraspecific genetic diversity. We used both mitochondrial DNA sequences (concatenated Cytb and D-loop , n = 78) and nuclear DNA (9 microsatellites loci, n = 154) molecular markers for individuals across the entire distribution of the species. We used phylogeographic trees, Bayesian clustering, and haplotype networks to explore genetic variation and diversity. We correlated genetic diversity with measures of current niche suitability and potential areas of Late Quaternary paleostability. Phylogeographic patterns confirmed low levels of genetic diversity structured at different hierarchical levels. We also found a weak but significant pattern of isolation by distance, indicating that geographical distance partially modulates genetic differences among populations. We also observed a positive correlation between genetic diversity and climate paleostability for microsatellites at local and regional scales. However, we found no significant association between genetic diversity and niche suitability for microsatellites at local or regional scales. We observed several signatures of bottleneck and population expansion at different geographic scales. Our results suggest that Quaternary climatic fluctuations—acting together with habitat suitability and other contemporary factors—played a fundamental role in elucidating the evolutionary history of the species—including patterns of historical dispersal, and current patterns of habitat occupation and genetic structure. In addition, based on our molecular and environmental data sets from the across the range of the species and considering the restricted endemism of C. flamarioni , we emphasize the urgency of conservation actions to protect this endangered species. [ABSTRACT FROM AUTHOR]

Dams are one of the main threats to Neotropical potamodromous fish, causing blockages of migratory routes and loss of breeding areas in an increasing number of drainage systems. In this scenario, current data argue that the maintenance of free-flowing tributaries along fragmented watersheds would be an important strategy to the migratory fish conservation, both in panmixia situations and in scenarios with different coexisting stocks, as already reported for Prochilodus lineatus. This study analyzed microsatellite loci and mitochondrial haplotypes in samples of P. lineatus obtained in different years along the Cinzas River basin, as well as in the Capivara Reservoir (largest Reservoir in the Paranapanema main channel, upper Paraná River) and in the Tibagi River, all connected by free stretches, aiming to investigate the contributions of the Cinzas River basin to the population dynamics of migratory fish in the Capivara reservoir region. Both markers detected high genetic diversity levels and indicated different genetic stocks of P. lineatus along the Cinzas River basin, suggesting some temporal genetic structuring, as well as the mixture of these stocks in the sample from the Capivara reservoir and from other points, corroborating the relationships among stocks in this reservoir and its tributaries. [ABSTRACT FROM AUTHOR]

Cnesterodon hypselurus is a small fish that has a restricted distribution in southern Brazil, including headwaters of the Tibagi and Itararé river basins (Upper Paraná River). This study reported C. hypselurus in a headwater of Cinzas River basin, where there were no previous records of this species, and employed microsatellite loci and mitochondrial haplotypes in a population genetic analysis. A total of 57 specimens was analyzed, including 30 from Cinzas River basin, 25 from Itararé River basin and two from Tibagi River basin. Results indicated low genetic diversity levels (HE = 0.334 and h = 0.246) for the sample from Cinzas River, suggesting reflections of a founder effect after the species had dispersed from one watershed to another, possibly by headwater captures. Since different populations were detected between the Cinzas and Itararé rivers (DEST = 0.248, P-value < 0.05) and other occurrence sites are still unknown in the Cinzas River basin, the data herein have great relevance and should be taken into account in future management and conservation actions, as well as in evolutionary studies of C. hypselurus. [ABSTRACT FROM AUTHOR]

Mangaba tree is a fruit tree species whose natural populations are fragmented by anthropic actions. For this reason, studies assessing the impact of fragmentation on the diversity and genetic structure of these populations are required in order to establish suitable conservation strategies. In our study, we used data from analyzes through microsatellite markers in computer simulations to estimate the rates of migration and selfing of six mangaba populations. The studied populations are located in the northeastern states of Ceará, Pernambuco and Sergipe. We tested different selfing and migration rates and selected the combination that showed values of observed and expected heterozygosity closest to those previously obtained with microsatellite markers. According to our simulations, selfing and migration were moderate. This may have led to an increase in inbreeding and genetic drift, resulting in low genetic diversity. We recommend expanding the area and reducing disturbance to promote the occurrence of pollinators, which play an important role in increasing genetic diversity. [ABSTRACT FROM AUTHOR]

Prochilodus lineatus is a species of migratory fish widely distributed in the Paraná River basin, found mainly in the Grande, Pardo and Mogi-Guaçu rivers located in a well-developed region of the state of São Paulo. This study analyzes the genetic diversity and population structure in shoals of P. lineatus based on temporal analysis of specimens sampled over the years 2003, 2005, 2006, 2009, 2010, and 2015 in the Mogi-Guaçu River, São Paulo, at the region of Cachoeira de Emas. Genetic analysis performed using the D-Loop and seven microsatellite marker revealed significant genetic variability in all sampled groups. Moderate levels of structuring between groups were identified with the microsatellite markers (Fst = 0.14), while the mitochondrial marker did not reveal patterns of genetic structuring (Fst = 0.01). The genetic variability fluctuated over time, characterizing patterns of structuring among the analyzed samples. The occurrence of environmental alterations resulting in increased mortality rates, as well as changes in the water level in the ecosystem, among other factors, could determine changes in the reproductive behavior of species. The lack of favorable environmental conditions for reproduction in the basin, as reflected by tests of population bottlenecks, could have resulted in the differentiation of populations of P. lineatus over time. [ABSTRACT FROM AUTHOR]

Molecular markers can be used to monitor genetic variability in cultivated fish stocks with the aim of developing better aquaculture techniques and increasing productivity. In view of the above, the objective of the present work was to evaluate the genetic variability in pirarucu broodstocks in fish farms in the southeast and northeast of the of Pará state, Brazil. The samples were genotyped using four microsatellite markers, and genetic diversity indices were calculated for each broodstock. A total of 16 alleles were identified from the four loci tested in the 33 pirarucu samples, with means of 3.00, 2.75, and 2.25 alleles per locus in broodstocks from Tucumã, Parauapebas, and Moju municipalities, respectively. The Parauapebas broodstock had the highest mean observed heterozygosity. In the broodstocks from Tucumã and Parauapebas, the markers AgCAm16 and AgCAm18 were not at Hardy-Weinberg equilibrium. This pilot study showed that there were considerable losses of genetic variability in pirarucu breeding centers in the municipalities of Tucumã, Parauapebas and Moju compared to the variability in the natural populations of this fish species. [ABSTRACT FROM AUTHOR]

Few twinning events have been recorded in the West Indian manatee (Trichechus manatus, Sirenia: Trichechidae) and no previous published study has provided confirmation of this phenomenon based in molecular tools. Here we investigate a possible case of twinning in an endangered Brazilian population of T. manatus using molecular tools. We analyzed two male neonates found stranded in Ceará State, on the northeastern coast of Brazil. The DNA of both individuals was isolated, and 10 microsatellite loci were amplified and genotyped. Following the identification of the alleles, the probabilities of identity by descent (Δ7 and Δ8) and relatedness (rxy) were calculated using estimators that evaluate inbreeding. The two individuals shared most of the alleles, with differences in the genotypes being identified in only two loci. All the estimators identified a level of relatedness compatible with that found between siblings (selfed or outbred), indicating they were dizygotic twins. This is the first confirmed case of fraternal twins in free-ranging West Indian manatees in South America. The recognition of this type of twinning provides elements to improve actions for the rehabilitation of stranded animals and their subsequent release to the environment. [ABSTRACT FROM AUTHOR]

Background: Two biotypes of Aberdeen Angus cattle breed, known as Old Type and New Type, that differ in their origin and beef production are formally recognized. In Colombia, this breed has been commercialized for approximately 80 years. Studies on the origin, kinship and levels of genetic diversity of this breed in Colombian herds are scarce, yet important for planning crossing and management strategies. Objective: To measure the genetic diversity and structure of two Colombian herds of Old Type and New Type biotypes of Aberdeen Angus from Huila and Cundinamarca provinces and assess mitochondrial introgression with other breeds. Methods: A set of ten microsatellites and sequences of the Mitochondrial Control Region were characterized. Estimators of genetic diversity and population differentiation along with tests of population assignment were applied. Results: Nuclear loci were highly polymorphic as shown by the Polymorphic Information Content (0.599) and the Probability of Identity (1.896 10-08). Both populations were highly diverse and clearly differentiated into two groups corresponding to the Old Type and New Type phenotypes. In contrast, mitochondrial data failed to distinguish these two groups and showed extensive admixture. Conclusions: This study optimized a set of ten highly polymorphic nuclear markers that may be used for parentage and population genetic studies of Aberdeen Angus. Genetic differentiation in these loci agreed with phenotypic differences of the Old and New Types. However, mitochondrial data indicated ancestry of multiple European breeds in the origin of Colombian Aberdeen Angus. [ABSTRACT FROM AUTHOR]

In recent years, anthropogenic factors such as pollution, overfishing, and construction of hydroelectric plants have significantly impacted natural fish populations. Research focusing on genetically evaluation of these impacts is necessary to objectively target conservation programs. The aim of this study was to evaluate the genetic diversity of Curimba (Prochilodus lineatus), Pacu (Piaractus mesopotamicus), and Piracanjuba (Brycon orbignyanus) populations from the Água Vermelha Reservoir, Rio Grande-SP. Microsatellite loci were amplified, producing 56, 24, and 26 alleles for the populations of the three species, respectively. The number of alleles per locus ranged from three to ten for P. lineatus, two to five for P. mesopotamicus, and two to four for B. orbignyanus. The observed heterozygosity (Ho) was higher in the P. lineatus population (0.547), relative to the P. mesopotamicus and B. orbignyanus populations (0.473 and 0.527, respectively). The mean values of Ho were lower than the average expected heterozygosity (He) in the three species, being corroborated by the positive inbreeding coefficient (Fis). Deviations from the Hardy-Weinberg equilibrium (HWE) were found in five, three, and two loci for P. lineatus, P. mesopotamicus, and B. orbignyanus, respectively. Wilcoxon tests revealed recent bottlenecks in the three species, evidenced by a significant excess of heterozygotes (p < 0.05) detected only in the Infinite Allele Model (IAM). In conclusion, adequate genetic variability was observed in the three populations with the presence of heterozygous deficits.

Endemic, small range species are susceptible to environmental changes and landscape modification. Understanding genetic diversity and distributional patterns is important for implementation of effective conservation measures. In this context, genetic diversity was evaluated to update the conservation status of an endemic tuco-tuco, Ctenomys ibicuiensis. Phylogeographic and population genetic analyses of mitochondrial DNA and microsatellite loci were carried out using 46 individuals sampled across the species' distribution. Ctenomys ibicuiensis presented moderate to high genetic diversity and highly structured populations with low levels of gene flow and isolation by distance. Anthropogenic landscape changes threaten this restricted-range tuco-tuco. Considering its limited geographic distribution and highly structured populations with low gene flow, we consider C. ibicuiensis to be at significant risk of extinction. [ABSTRACT FROM AUTHOR]

O objetivo deste estudo foi avaliar o sistema de fecundação e a distribuição da variabilidade molecular entre e dentro de três grupos de progênies de polinização aberta de Euterpe oleracea, além de realizar um teste de paternidade para identificação dos genitores masculinos e promover a certificação genética das plântulas bífolioladas. Para tal, foram utilizados seis loci microssatélites em 306 amostras. Os grupos de progênies são resultado de um sistema misto de fecundação, com ausência de cruzamentos entre aparentados, sendo alógamos (tm e ts = 1,0), com correlação de autofecundação (rt) igual a 0,110. Foram constatados diferentes graus de parentescos (rp), entre 15,5 a 26,1% de irmãos completos. A paternidade foi atribuída para 51% e 24% das amostras, com 80 e 95% de confiança respectivamente. Foram identificados 22 doadores de pólen e uma autofecundação, verificou-se que o morfotipo bífoliolado não é garantia de cruzamento intraespecifico, já que quatro progênies foram identificadas como híbridos interespecíficos. Foram detectados em média 7 a 12,3 alelos por locus e uma heterozigosidade média observada entre 0,382 a 0,898 e a esperada entre 0,354 a 0,693. O índice de fixação foi entre -0,053 a -0,319. A variação entre os grupos foi de 5%, sendo 95% dentro deles. Os resultados indicam boas perspectivas para realização de trabalhos futuros relacionados à predição de ganhos genéticos a partir da seleção entre e dentro dos grupos de progênies.

Behavioral observations made on fish have revealed remarkably diverse reproductive strategies, including polygamy by both sexes. Still, to date, most Neotropical species remain unstudied as to whether the observed reproductive behavior in natural populations correlates with their genetic mating systems. Here, we investigated the genetic mating system of a wild population of Prochilodus lineatus settled in the Middle Uruguay River basin. By using sibship reconstruction and parental inference methods based on microsatellites' genotypes, we inferred 45 females and 47 males as potential parents of the 87 larvae analyzed. We found evidence supporting polygamous mating in both sexes: while a high percentage of males (44.7%) fertilized the eggs of one female, 55.3% of the inferred males fertilized eggs of up to four females. Likewise, while 44.5% of the inferred females had their eggs fertilized by one only male, 55.5% of females were fertilized by multiple males. The estimated proxy of the effective population size (Nb) was 126, exhibiting moderate to high levels of genetic diversity. The genetic evidence contributed in this study complements earlier behavioral observations of formation of spawning nuclei of aggregating breeders, which may be promoting a polygamous mating strategy in this long-distance migratory fish. [ABSTRACT FROM AUTHOR]

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Hymenaea courbaril L. (Fabaceae) is a tree species popularly known as 'jatobá'. Its wood is largely sold and its fruits are used as a food and medicinal resources. This species has been subjected to logging and habitat destruction. The knowledge about genetic polymorphism is important for the conservation of species affected by anthropic action. In this study, we analyzed the genetic diversity of natural populations of Hymenaea courbaril in the Mato Grosso Amazon. Seven microsatellite primers were used to genotyping of 43 individuals distributed in five populations in the north region of Mato Grosso State. All the seven primers were polymorphic, with 72 alleles detected, averaging 10.29 per locus. Expected and observed heterozygosities averaged 0.85 and 0.29 per locus, respectively. The fixation index was positive for all populations, suggesting excess homozygotes, probably due to inbreeding. Molecular analysis of variance revealed that 85.33% of genetic diversity is within the populations. Based on the UPGMA dendrogram, the individuals were divided into six groups. In the clustering provided by Structure software, four groups were formed which did not correspond to the geographic distribution of the individuals, indicating that the populations are not geographically structured. All sampled populations present elevated levels of genetic diversity, and so they can be used for conservation projects. Genetic variation is higher within the analyzed populations; therefore, several individuals must be conserved per population. [ABSTRACT FROM AUTHOR]

Resumo O objetivo deste trabalho foi caracterizar geneticamente e avaliar a estrutura populacional de galinhas crioulas Canela-Preta de três plantéis pertencentes aos municípios de Teresina, Oeiras e Queimada Nova, no Estado do Piauí. Utilizaram-se 12 marcadores microssatélites e amostras de DNA de 118 galinhas. Após a extração do DNA, os marcadores microssatélites foram amplificados por meio da técnica de reação em cadeia da polimerase (PCR). Efetuaram-se análises estatísticas da estimativa de heterozigosidades observada e esperada, análise de variância molecular, análise de componentes principais, estatística F de Wright e análise de estrutura populacional com base em análise bayesiana. As análises de diferenciação genética (Amova) sugerem baixa diferenciação entre os núcleos avaliados, o que indica se tratar geneticamente de um único grupo. Os resultados da estatística F indicaram tendência de endogamia dos plantéis estudados. O gráfico de dispersão e análise bayesiana, usado para mostrar a estrutura das aves Canela-Preta, sugeriu a existência de quatro grupos genéticos e revela que há fluxo gênico entre os plantéis analisados. Os marcadores moleculares microssatélites avaliados apresentam-se polimórficos, o que mostra alta variação nas amostras e revela sua eficiência no estudo de caracterização. Os resultados são indicativos de que as galinhas Canela-Preta estão geneticamente estruturadas.

Nos últimos anos, fatores antrópicos como poluição, sobrepesca e construção de hidrelétricas têm impactado significativamente as populações naturais de peixes. Pesquisas que permitam avaliar geneticamente esse impacto são necessárias para orientar objetivamente programas de conservação. O objetivo do presente estudo foi avaliar a diversidade genética de populações de Curimba (Prochilodus lineatus), Pacu (Piaractus mesopotamicus) e Piracanjuba (Brycon orbignyanus) provenientes do reservatório de Água Vermelha, Rio Grande-SP. Foram amplificados loci microssatélites que produziram 56, 24 e 26 alelos para as populações das três espécies, respectivamente. O número de alelos por locus variou de três a dez para P. lineatus, dois a cinco para P. mesopotamicus e dois a quatro para B. orbignianus. A heterozigosidade observada (Ho) foi mais elevada na população de P. lineatus (0,547) em relação às populações de P. mesopotamicus e B. orbignyanus (0,473 e 0,527, respectivamente). A média dos valores de Ho foram inferiores à média de He nas três espécies sendo corroborado pelo Fis positivo observado. Foi encontrado desvio do equilíbrio de Hardy-Weinberg (HWE) em cinco loci para P. lineatus, três loci para P. mesopotamicus e dois em B. orbignyanus. A análise de bottleneck revelou excesso de heterozigotos (p < 0,05) pelo teste de Wilcoxon nas três espécies apenas no modelo Infinite Allele Model (IAM). Foi observada adequada variabilidade genética nas três populações com a presença de déficit de heterozigotos.

Acasalamentos duvidosos são uma das causas dos erros nos programas de conservação e de melhoramento genético de raças. Os testes de paternidades são ferramentas que podem contribuir para minimizar esses erros pois tem sido usados para identificar paternidade duvidosa. O presente trabalho teve como objetivo definir um painel para teste de paternidade em caprinos para auxiliar programas de conservação e melhoramento de raças. Foram genotipados 381 animais de 10 populações caprinas sendo seis ecotipos locais brasileiros e quatro raças exóticas utilizadas atualmente no Brasil (Alpina, Anglo-Nubiana, Boer e Saanen). Realizou-se nove sistemas multiplex, totalizando 27 microssatélites. Foram estimados o PIC, as probabilidades de exclusão dos marcadores e o equilíbrio de Hardy-Weinberg (EHW) nas populações, seguida de determinação da probabilidade de identidade (PI). Para o sistema de 27 microssatélites a probabilidade de exclusão combinada (PE) foi de 0,999 e 0,999 (PE1 e PE2) e, 21 microssatélites apresentaram PIC ? 0,60, onde quatro apresentaramse monomórficos em algumas populações. Para compor o novo painel foram escolhidos 9 marcadores dos quais oito comuns aos dois grupos estudados (caprinos locais e exóticos), sendo o BM1818 mais informativo nas populações locais e, o marcador BM6506 nas populações exóticas. A probabilidade de exclusão combinada com o grupo dos microssatélites foi de 0,994 e 0,999 (PE1 e PE2). Baseado no cálculo das probabilidades de identidade dentro das populações foi possível discriminar um indivíduo entre um milhão (106). Os resultados indicaram a possibilidade de empregar poucos microssatélites na investigação de paternidade em caprinos, com alto grau de confiabilidade, minimizando assim custos para o criador.

Gene flow is important for the conservation of genetic resources to allow connectivity of geographically isolated populations and which genetic variability is reduced. Gene movement is a function of flow rate and model. Understanding how gene flow occurs can contribute to the conservation and selection of priority populations that could benefit from an eventual intervention. Simulation softwares allow making inferences about past events based on current datasets or predict future phenomena under real genetic scenarios. Adverse phenomena can be predicted and actions can be taken to avoid them. The aim of this study was to identify a model and the gene flow rates that could explain genetic structure of eight forest fragments of Cabralea canjerana in development in the Brazilian Atlantic Rainforest. To do this, simulations were performed with the EASYPOP software using a microsatellite marker dataset obtained for the species by Melo and collaborators, in 2012, 2014 and 2016. We tested five models and nine migration rates and we selected the model that produced values closer to those previously obtained for them. Criteria used for selection were the observed and expected heterozygosity and the Wright's F Statistics obtained in the simulations. The gene flow model selected was the isolation by distance model that used a rate of 0.1. We observed high levels of genetic differentiation among the fragments as result of their reproductive isolation. To allow homogenization of the allelic frequencies through gene flow, the solution would be to create ecological corridors with the aim of connecting distant fragments. [ABSTRACT FROM AUTHOR]

Background: Piracanjuba (Brycon orbignyanus) is a fish species highly affected by anthropogenic actions such as overfishing, water pollution, and hydroelectric developments. This species is currently considered in danger of extinction. Objective: To analyze the genetic diversity of a natural population (NP) and two captive broodstocks (SA and SB) of B. orbignyanus. Methods: Samples of caudal fins (NP: 24, SA: 30, and SB: 30) were collected. DNA was extracted and amplified for six RAPD primers and four microsatellite loci. Results: Sixty polymorphic fragments and 17 microsatellite alleles were detected. High intrapopulation heterozygosity (NP: 0.692, SA: 0.724, and SB: 0.686) was observed. Thirty-eight fragments and six alleles were shared among NP, SA, and SB. The FIS and Shannon's Index of diversity revealed a lack of inbreeding within groups. AMOVA analyses and FST indicated very high (NP vs SA and SB) and small (SA vs SB) genetic differentiation, confirmed by genetic distance and identity, number of migrants and a dendrogram, which revealed the formation of two genetic groups. Conclusions: The two marker types showed similar variability. The groups have adequate genetic variability, with high differentiation between NP and SA-SB, and similarity between broodstocks. [ABSTRACT FROM AUTHOR]

As vinhas antigas dos Açores são constituídas essencialmente por 3 castas: ‘Verdelho’, ‘Arinto dos Açores’ e ‘Terrantez do Pico’. Estas castas apresentam grande singularidade no contexto vitícola nacional, não sendo conhecida a sua presença em vinhas antigas do território continental português. Apesar de ao longo do tempo várias hipóteses terem sido colocadas quanto à origem destas castas, esta continua insuficientemente clarificada. No presente trabalho propõe-se que a hibridação de castas nas vinhas açorianas esteja na origem das castas ‘Terrantez do Pico’ e ‘Arinto dos Açores’, com o ‘Bastardo’ como provável progenitor da primeira e o ‘Verdelho’ como possível progenitor de ambas. Discute-se ainda a origem da casta ‘Verdelho’ e a sua ligação com diversas castas do Noroeste da Península Ibérica.

ABSTRACT The aim of this study was to evaluate the genetic diversity and structure in the germoplasm of Oenocarpus mapora conserved at Eastern Amazon. Thus, 88 individuals were genotyped with five microsatellite loci. These individuals belong to 24 accessions that were sampled in eight sample places of three Brazilian Amazon states conserved at the Active Germplasm Bank (AGB) of Embrapa Eastern Amazon. All loci were polymorphic and they generated 85 alleles with an average of 17 alleles per loci. Total genetic diversity (HE) was 0.48. Sample places were considered genetically distinct, with ?p = 0.354. The analysis of molecular variance (AMOVA) identified that the genetic portion among areas was of 36.14% and within 63.86%. The Nei distances varied from 0.091 between Abaetetuba and Santo Antônio do Tauá, both in the state of Pará (PA), to 4.18, between Parintins, AM and Rio Branco, AC. By means of Bayesian analysis, it was identified nine clusters that compose the accessions of the germplasm bank, with different distributions among individuals. The study showed high fixation rates per sample area, which indicates that there may have been significant inbreeding or crossing among parental individuals. It suggests that future samples should be made of different plants in natural populations. Even though, it was verified that there is considerable genetic variation in the germplasm of O. mapora.

ABSTRACT The macaw palm, Acrocomia aculeata (Jacq.) Lodd. ex Mart., is a Brazilian native species with great potential for biofuel production. The aim of this work was to analyze macaw palm genetic diversity to structure and assist in the definition of sampling strategies for germplasm banks. Forty-six microsatellite markers, from which seven polymorphic markers were used to evaluate 103 macaw palm individuals collected from different Brazilian locations. The polymorphic markers were used to generate a dissimilarity matrix by weighted index. The imaging of genetic variability was realized by 3D projection of matrix dissimilarity. Sixty-seven individuals had their ITS region sequenced and aligned, and the mutations found were used to generate a haplotype network. The average genetic distance identified between individuals was 76.2%, ranging from 3.7 to 100%. Genetic variability structure was not found. ITS region sequencing of the 67 individuals revealed four polymorphic sites, defining four haplotypes. The results of this study suggest that historically, macaw populations were strongly connected, indicating a recent population expansion of the species. The results indicate that macaw genetic variety sampling should focus on effective collection in selected locations. Areas such as Caatinga and Humid Chaco however, could present new sources of genetic variability, and should be studied.

This study aimed to investigate the genetic variability of two Brazilian free range (Caipira) chickens lines using microsatellites analysis of ten loci. It was collected a total of 99 blood samples, which 49 were from Paraíso Pedrês (PP) and 50 were from Rubro Negra (RN) lines. The amplification of the DNA fragments was performed by polymerase chain reaction (PCR) and the genotyping was conduct using ABI 3130 sequencer. The allele number variation was among 3 (LEI0254) to 32 (LEI0212) in the PP line, and 4 (LEI0254) to 31 (LEI0212) in the RN line. The allelic average per locus was 13.3 and 13.1 in the PP and RN lines, respectively. The average observed and the expected heterozygosity were 0.650 and 0.820 in the PP line, and 0.671 and 0.804 in the RN line. All of the analyzed loci were informative (PIC>0.5). These results indicate that these free-range animals have a high genetic variability, at least for the majority of the analyzed loci, and this genetic variation is higher than the commercial chickens and similar for the no-commercial birds

This study analyzed the reproductive system and the pollen dispersion pattern of Qualea grandiflora progenies. This is a typical species from the Brazilian Cerrado about which there are not too many studies from the genetics point of view. The study was conducted in an area of 2.2 hectares located in the Conservation Unit managed by the Forest Institute of the state of São Paulo, Brazil (Assis State Forest). Total genomic DNA of 300 seeds from 25 plants (12 seeds from each plant) was extracted and amplified using specific primers to obtain microsatellite markers. Results showed that selfing is frequent among adults and progenies, and the species reproduces by outcrossing between related and unrelated individuals (0.913). The single-locus outcrossing rate was 0.632, which indicates that mating between unrelated individuals is more frequent than between related plants. The selfing rate was low (0.087), that is, the species is allogamous and self-fertilization is reduced. About 35% of the plants in the progenies were full-sibs, and about 57%, half-sibs. Besides, about 8% of the progenies were selfing siblings. The genetic differentiation coefficient within progenies was 0.139, whereas the fixation rate was about 27%. The estimate of the effective size revealed that the genetic representativeness of descent was lower than expected in random mating progenies: The analyzed samples corresponded to only 13.2 individuals of an ideal panmictic population. In environmental recovery programs, seeds, preferably from different fruits, should be collected from 95 trees to preserve the genetic diversity of the species.

The objective of this work was to assess the genetic diversity and population structure of wheat genotypes, to detect significant and stable genetic associations, as well as to evaluate the efficiency of statistical models to identify chromosome regions responsible for the expression of spike-related traits. Eight important spike characteristics were measured during five growing seasons in Serbia. A set of 30 microsatellite markers positioned near important agronomic loci was used to evaluate genetic diversity, resulting in a total of 349 alleles. The marker-trait associations were analyzed using the general linear and mixed linear models. The results obtained for number of allelic variants per locus (11.5), average polymorphic information content value (0.68), and average gene diversity (0.722) showed that the exceptional level of polymorphism in the genotypes is the main requirement for association studies. The population structure estimated by model-based clustering distributed the genotypes into six subpopulations according to log probability of data. Significant and stable associations were detected on chromosomes 1B, 2A, 2B, 2D, and 6D, which explained from 4.7 to 40.7% of total phenotypic variations. The general linear model identified a significantly larger number of marker-trait associations (192) than the mixed linear model (76). The mixed linear model identified nine markers associated to six traits.

In this work, 25,806 potentially amplifiable microsatellite loci (PAL) were identified in pejerrey, (Odontesthes humensis), with 21% of dinucleotide, 22% trinucleotide, 37% tetranucleotide, 13% pentanucleotide and 7% hexanucleotide. Of the total loci, 167 were classified as "Best PAL", more likely to be variables in populations. The results show that with a small coverage of the genome it was possible to identify a large number of microsatellite loci.

The Chilean strawberry [Fragaria chiloensis (L.) Mill.] is the maternal progenitor of the commercial strawberry (Fragaria x ananassa Duch.), which is characterized by fruits with high organoleptic quality and is well-suited to areas where drought and salinity represent a constraint on crop growth and productivity. We examined the patterns of linkage disequilibrium, genetic diversity and population structure among 54 accessions of F. chiloensis to understand the genetic basis of this species. We used a core microsatellite marker set (n = 95) from a consensus linkage map of strawberry. A transferability rate of 82.1% (78/95) was found, and 38 markers were selected for this study. The SSR primers produced a total of 259 alleles, which varied between 112 and 342 bp. Lower genetic diversity at the species level (HE = 0.17, Shannon's index = 0.28) was found compared to previous studies of this species. No climatic region pattern for SSR diversity was observed. Structure analysis suggests that the accessions are grouped into three significantly differentiated clusters. Pairwise estimates of φST indicated a low degree of differentiation between the three genetic groups (φST = 0.023 to 0.06). These groups are in concordance with potential glacial refugia in the region, with many accessions being an admixture of them. [ABSTRACT FROM AUTHOR]

The stingless bees of tribe Meliponini are efficient pollinators playing a key role in ecosystem services. Frieseomelitta Friese (Hymenoptera: Apidae: Meliponini) includes 16 Neotropical species, of which 6 are found in the state of Bahia, northeastern Brazil. In order to provide a refined cytotaxonomic analysis, we characterized the heterochromatin composition and variation among 6 Frieseomelitta species. All species shared a diploid number (2n) of 30 chromosomes. Frieseomelitta dispar Moure, Frieseomelitta francoi Moure, and Frieseomelitta meadewaldoi Cockerell (Hymenoptera: Apidae), presented GC-rich heterochromatic regions while Frieseomelitta sp.n., Frieseomelitta varia Lepelitier, and Frieseomelitta doederleini Friese (Hymenoptera: Apidae) were characterized by homogenous heterochromatin, without evidence of AT or GC-rich sites. The number and location of microsatellite repeats mapped by fluorescence in situ hybridization revealed interspecific variation. These data were useful to identify each species based on chromosomal markers, and represent important tools for clarifying the interspecific differentiation among Frieseomelitta species and for understanding the genome evolution in bees as a whole. [ABSTRACT FROM AUTHOR]

The raspberry berries have outstanding nutritional and taste qualities and contain high levels of compounds with antioxidant activity (anthocyanins and others). Breeding of raspberries for the improvement of food traits can be significantly accelerated through the application of molecular markers. Seventeen varieties of raspberry and blackberry, including thirteen Russian cultivars with a wide variation of the berries coloring, were analyzed using 13 microsatellite loci. It is shown that the loci FJ194454, FJ194451, and AF29236 are specific only for raspberry, and the locus FJ194450 is only for blackberry. It has been established that the studied microsatellite loci can be used to identify raspberry cultivars of the Russian selection. It is shown that varieties with different coloring differ in the number of alleles in some microsatellite loci, what can be used for markerassisted selection for the content of anthocyanins. [ABSTRACT FROM AUTHOR]

The Chilean strawberry [Fragaria chiloensis (L.) Mill.] is the maternal progenitor of the commercial strawberry (Fragaria x ananassa Duch.), which is characterized by fruits with high organoleptic quality and is well-suited to areas where drought and salinity represent a constraint on crop growth and productivity. We examined the patterns of linkage disequilibrium, genetic diversity and population structure among 54 accessions of F. chiloensis to understand the genetic basis of this species. We used a core microsatellite marker set (n = 95) from a consensus linkage map of strawberry. A transferability rate of 82.1% (78/95) was found, and 38 markers were selected for this study. The SSR primers produced a total of 259 alleles, which varied between 112 and 342 bp. Lower genetic diversity at the species level (HE = 0.17, Shannon's index = 0.28) was found compared to previous studies of this species. No climatic region pattern for SSR diversity was observed. Structure analysis suggests that the accessions are grouped into three significantly differentiated clusters. Pairwise estimates of φST indicated a low degree of differentiation between the three genetic groups (φST = 0.023 to 0.06). These groups are in concordance with potential glacial refugia in the region, with many accessions being an admixture of them. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the genetic dissimilarity among sweet potato genotypes using morphological and molecular descriptors. The experiment was conducted in the Olericulture Sector at Federal University of Jequitinhonha and Mucuri Valleys (UFVJM) and evaluated 60 sweet potato genotypes. For morphological characterization, 24 descriptors were used. For molecular characterization, 11 microsatellite primers specific for sweet potatoes were used, obtaining 210 polymorphic bands. Morphological and molecular diversity was obtained by dissimilarity matrices based on the coefficient of simple matching and the Jaccard index for morphological and molecular data, respectively. From these matrices, dendrograms were built. There is a large amount of genetic variability among sweet potato genotypes of the germplasm bank at UFVJM based on morphological and molecular characterizations. There was no duplicate suspicion or strong association between morphological and molecular analyses. Divergent accessions have been identified by molecular and morphological analyses, which can be used as parents in breeding programmes to produce progenies with high genetic variability. [ABSTRACT FROM AUTHOR]

A Floresta Atlântica vem sendo afetada por ações antrópicas ao longo no tempo e ainda continua sofrendo com essas ameaças. A fragmentação florestal ocasionada pelo desmatamento e o corte seletivo de espécies arbóreas contribui significativamente para a perda de diversidade genética nas populações naturais. Anadenanthera peregrina é uma espécie arbórea de grande porte e está sob efeito da fragmentação e corte seletivo. Análises genéticas a nível populacional são importantes para direcionar estratégias conservacionistas. Neste trabalho foi avaliada a diversidade genética de uma amostra populacional de trinta e cinco indivíduos de A. peregrina utilizando marcadores SSR. As análises permitiram dizer que a população não é endogâmica, provavelmente pelo fato da espécie ser predominantemente auto incompatível predominando a fecundação cruzada. A diversidade genética foi inferior a outros trabalhos com a mesma espécie, possivelmente pelo histórico da área. As árvores amostradas podem servir como fonte de sementes para produção de mudas destinadas ao reflorestamento.

The loss of large areas of Cerrado (Brazilian savanna) in Brazil can lead to reduced biodiversity and to the extinction of species. Therefore, the present study aimed to investigate the genetic fragility of populations of Copaifera langsdorffii Desf exposed to different anthropic conditions in fragments of Cerrado in the state of São Paulo. The study was carried out in two Experimental Stations operated by the Forest Institute (Assis and Itirapina), in one fully protected conservation unit (Pedregulho) and in one private property (Brotas). Analyses were conducted using leaf samples from 353 adult specimens and eight pairs of microsatellite loci. The number of alleles per locus ranged from 13 to 15 in all populations, but the mean number of effective alleles was approximately half this value (7.2 to 9-1). Observed heterozygosity was significant and lower than the expected in all populations. Consequently, all populations deviated from Hardy-Weinberg expected frequencies. Fixation indexes were significant for all populations, with the Pedregulho population having the lowest value (0.189) and Itirapina having the highest (0.283). The analysis of spatial genetic structure detected family structures at distance classes of 20 to 65 m in the populations studied. No clones were detected in the populations. Estimates of effective population size were low, but the area occupied by each population studied was large enough for conservation, medium and long term. Recent reductions or bottlenecks were detected in all four populations. Mean Gst’ (genetic divergence) indicated that most of the variation was within populations. Cluster structure analysis based on the genotypes detected K= 4 clusters with distinct allele frequencies patterns. The genetic differentiation observed among populations is consistent with the hypothesis of genetic and geographic isolation. Therefore, it is essential to adopt conservation strategies that raise the gene flow between fragments.

O objetivo deste trabalho foi avaliar, por meio de marcadores SSR, a diversidade genética de Xylella fastidiosa no Estado da Bahia. Foram estudadas duas das principais regiões produtoras de citros no Estado, o Litoral Norte e o Recôncavo Sul. Para fins comparativos, utilizaram-se dez amostras provenientes do Estado de São Paulo. Foram empregados os seguintes iniciadores: ASSR20, OSSR9, OSSR17, CSSR4, CSSR12 e CSSR20, dos quais os quatro últimos permitiram identificar 22 loci polimórficos. As populações de X. fastidiosa presentes em citros no Estado da Bahia apresentam elevada diversidade genética, com base nos marcadores SSR, com pools gênicos distintos e agrupamento geográfico. No Litoral Norte, as populações do isolado apresentam maior diversidade genética do que as da região do Recôncavo Sul da Bahia.

Seabirds are of considerable conservation significance due to their key role in ecosystems and their generally high level of threat, especially from invasive species in breeding sites and as a result of bycatch during commercial fishing activities. We examined the genetic diversity, evidence for a bottleneck, and effective population size (Ne) of Redbilled Tropicbirds (Phaethon aethereus) from the Abrolhos Archipelago and White-tailed Tropicbirds (P. lepturus) from Fernando de Noronha Archipelago, both in the southwestern Atlantic Ocean. In addition, intraspecific genetic distance was assessed between 2 Red-billed Tropicbirds breeding on Fernando de Noronha and the larger population on Abrolhos, and between 5 White-tailed Tropicbird individuals breeding on Abrolhos and the breeding population on Fernando de Noronha, to identify relict populations. From 11 microsatellite loci, observed heterozygosity was 0.471 for White-tailed Tropicbirds and 0.267 for Red-billed Tropicbirds. Additionally, We was estimated to be as low as 100-200 individuals for each species, ~25-50% of recent census estimates for the largest population of each species. No deviation from mutation-drift equilibrium was detected, but both species had M-ratios indicative of populations that had experienced a bottleneck or been recently established, and seem to have persisted as small populations over the past few centuries on both archipelagos. Small population size coupled with low evolutionary potential make these populations vulnerable to extinction. In our study sites and worldwide, tropicbirds show slow population growth and vulnerability to introduced predators. These species would benefit from both colony-based management and a better understanding of patterns of genetic diversity within and among populations. [ABSTRACT FROM AUTHOR]

The objective of this work was to characterize morphologically and molecularly the genetic diversity of cassava accessions, collected from different regions in Brazil. A descriptive analysis was made for 12 morphological traits in 419 accessions. Data was transformed into binary data for cluster analysis and analysis of molecular variance. A higher proportion of white or cream (71%) root cortex color was found, while flesh colors were predominantly white (49%) and cream (42%). Four accession groups were classified by the cluster analysis, but they were not grouped according to their origin, which indicates that diversity is not structured in space. The variation was greater within regions (95.6%). Sixty genotypes were also evaluated using 14 polymorphic microsatellite markers. Molecular results corroborated the morphological ones, showing the same random distribution of genotypes, with no grouping according to origin. Diversity indices were high for each region, and a greater diversity was found within regions, with: a mean number of alleles per locus of 3.530; observed and expected heterozygosity of 0.499 and 0.642, respectively; and Shannon index of 1.03. The absence of spatial structure among cassava genotypes according to their origins shows the anthropic influence in the distribution and movement of germplasm, both within and among regions.

The development of homozygous breeding lines in maize may be accelerated through the use of haploids. Thus, the obtaining and prior identification of haploids generated by the haploid inducer lines is an important factor. The purpose of this study was to identify haploids by flow cytometry and to correlate the nuclear DNA content to the morphological and morphometric traits of the seeds that gave rise to them. In addition, molecular markers were used to confirm the androgenetic nature of the haploid. The seeds obtained were derived from the cross between the inbred line W23 and the commercial hybrid P30F90. Among these seeds, a group was selected, putative haploids, whose embryo was white and the pericarp purplish. This group, consisting of 330 seeds, was characterized based on seed morphology, seed morphometry and nuclear DNA content. Flow cytometry analyses identified four haploids, and all of them were small size plants and had brittle leaves. The weight, length, thickness and width of the haploid seeds were very variable indicating that morphometric traits do not constitute reliable data for visual selection of haploid seeds. Based on results, the inbred line W23 induced haploid maize even under tropical conditions. Microsatellite molecular markers (SSR) proved to be efficient, confirming the androgenetic trait of the haploids.O desenvolvimento de linhagens homozigotas em milho pode ser acelerado por meio do uso de haploides. Para isso, a obtenção e identificação prévia dos haploides gerados pelas linhagens indutoras de haploidia é um fator importante. O objetivo do trabalho foi identificar haplóides por meio de citometria de fluxo para então correlacionar o conteúdo de DNA nuclear aos caracteres morfológicos e morfométricos das sementes que os originaram. Além disso, marcadores moleculares foram utilizados para confirmar a natureza androgenética do haploide. As sementes obtidas foram provenientes do cruzamento entre a linhagem W23 e o híbrido comercial P30F90. Dentre essas sementes, foi selecionado um grupo, possíveis haplóides, cujo embrião era branco e o pericarpo arroxeado. Esse grupo, constituído de 330 sementes, foi caracterizado quanto à morfologia, morfometria e conteúdo de DNA nuclear. As análises de citometria de fluxo identificaram quatro haploides, e todos eles apresentaram porte reduzido e folhas quebradiças. Os pesos, comprimentos, espessuras e larguras das sementes haplóides variaram muito, indicando que caracteres morfométricos não são eficientes para a seleção visual de haploides. Baseado nos resultados, a linhagem W23 induz haplóides em milho mesmo em condições tropicais. Os marcadores moleculares microssatélites (SSR) mostraram-se eficientes, comprovando o caráter androgenético dos haploides.

Flowering time is an important trait for tree breeding because it determines the speed of generation turnover and therefore the rapidity of genetic gains, and it is of particular interest in Eucalyptus species. In this work, we used simple sequence repeats (SSRs), random amplified polymorphic DNA (RAPD) analysis and specific markers for flowering to evaluate early flowering segregation in a full-sibling family of Eucalyptus grandis and to identify molecular markers associated with the control of flowering time. A cross between a normal flowering tree (wild-type) and early flowering tree resulted in 118 progeny with a 1:1 Mendelian segregation ratio for flowering time (χ2 = 0.5424, P > 0.05), which suggested the action of one main gene in a locus named Early flowering in Eucalyptus grandis (PFEg). The SSR marker EMBRA 02 was related to the QTL PFEg, and identified this region as a candidate for trait control. These maps may be used as the basis for a study in which can be inserted new markers in an attempt to find more loci related to early flowering characteristic on eucalyptus. O tempo de florescimento é uma importante característica para o melhoramento genético de árvores, pois este determina o prazo para o surgimento de uma nova geração e a rapidez para o ganho genético de uma determinada espécie, como por exemplo, Eucalyptusgrandis. Neste estudo foram utilizados marcadores moleculares do tipo microssatélites, Random Amplified Polymorphism DNA – RAPD, além de marcadores específicos para avaliar a segregação do florescimento precoce em uma família de irmãos-germanos de E. grandis. Foi também verificado se esses marcadores estão associados ao controle do tempo de florescimento na espécie. A progênie de 118 indivíduos avaliada foi originada do cruzamento entre uma árvore de florescimento normal e outra de florescimento precoce. A segregação da característica de florescimento precoce apresentou uma razão de 1:1 (χ2 = 0,5424, P > 0,05), o que sugeriu a ação de um gene principal no loco denominado PFEg (Florescimento Precoce em Eucalyptus grandis). O marcador SSR EMBRA 02 foi relacionado ao QTL PFEg e esta região foi identificada como uma região candidata ao controle da característica. Estes mapas poderão ser utilizados como base para um novo estudo no qual podem ser inseridos novos marcadores na tentativa de localizar mais regiões relacionadas à característica de florescimento precoce em eucalipto.

The objective of this work was to estimate the genetic diversity of improved banana diploids using data from quantitative analysis and from simple sequence repeats (SSR) marker, simultaneously. The experiment was carried out with 33 diploids, in an augmented block design with 30 regular treatments and three common ones. Eighteen agronomic characteristics and 20 SSR primers were used. The agronomic characteristics and the SSR were analyzed simultaneously by the Ward-MLM, cluster, and IML procedures. The Ward clustering method considered the combined matrix obtained by the Gower algorithm. The Ward-MLM procedure identified three ideal groups (G1, G2, and G3) based on pseudo-F and pseudo-t² statistics. The dendrogram showed relative similarity between the G1 genotypes, justified by genealogy. In G2, 'Calcutta 4' appears in 62% of the genealogies. Similar behavior was observed in G3, in which the 028003-01 diploid is the male parent of the 086079-10 and 042079-06 genotypes. The method with canonical variables had greater discriminatory power than Ward-MLM. Although reduced, the genetic variability available is sufficient to be used in the development of new hybrids.

A realização do presente estudo teve como objetivo mapear Quantitative Trait Loci (QTL) de carcaça e qualidade de carne em uma população F2 de suínos desenvolvida pelo cruzamento de dois reprodutores da raça brasileira Piau com 18 fêmeas comerciais (Landrace x Large White x Pietrain). O mapa de ligação para essa população foi construído após a genotipagem de 684 animais para 35 marcadores microssatélites. Os dados foram analisados pelo mapeamento por intervalo usando-se sexo, lote e genótipo halotano como efeitos fixos e peso de carcaça ao abate, peso da carcaça direita e idade ao abate como covariáveis. Um total de 18 QTLs foi encontrado; os QTLs para maior espessura de toucinho na região da copa, na linha dorsolombar, e a perda por cozimento foram significativos em nível de 5% genômico. A característica espessura de toucinho foi essencialmente associada aos alelos da raça Piau, conhecido como porco tipo banha. As informações dos QTLs significativos encontrados servem para futuros estudos de mapeamento fino para identificação de genes a serem usados em conjunto com os métodos tradicionais de seleção, para melhorar a eficiência dos programas de melhoramento, assim como prover informação acerca da fisiologia envolvida no desenvolvimento das características quantitativas dos suínos.

The main objectives of hybrid development programs include incorporating genetic resistance to diseases and increasing grain yield. Identification of Quantitative Trait Loci (QTL) through the statistical analysis of molecular markers allows efficient selection of resistant and productive hybrids. The objective of this research was to identify QTL associated with resistance to gray leaf spot and for grain yield in the germplasm of tropical corn. We used two strains with different degrees of reaction to the disease; the genotypes are owned by GENESEEDS Ltda, their F1 hybrid and the F2 population. The plants were evaluated for gray leaf spot resistance, for grain yield and were genotyped with 94 microsatellite markers. Association of the markers with the QTL was performed by single marker analysis using linear regression and maximum likelihood analysis. It was observed that the additive effect was predominant for genetic control of resistance to gray leaf spot, and the dominant effect in that of grain yield. The most promising markers to be used in studies of assisted selection are: umc2082 in bins 4.03 and umc1117 in bins 4.04 for resistance to gray leaf spot; for grain yield umc1042 in bins 2.07 and umc1058 in bins 4.11.A incorporação de resistência genética a doenças e o aumento na produtividade de grãos estão entre os principais objetivos dos programas de desenvolvimento de híbridos. A identificação de locos de caracteres quantitativos (QTL) por meio de análises estatísticas associadas a marcadores moleculares possibilita a rápida obtenção de híbridos resistentes e produtivos. Nesta pesquisa, objetivou-se identificar locos de caracteres quantitativos (QTL) associados com resistência à cercosporiose e com produção de grãos em germoplasma de milho tropical. Foram utilizadas duas linhagens contrastantes em níveis de reação à doença (genótipos pertencentes à GENESEEDS - Ltda), seu híbrido F1 e a população segregante F2. Essas plantas foram fenotipadas quanto à resistência a doença e quanto a produção de grãos e genotipadas com 94 marcadores de microssatélites. A associação dos marcadores ao QTL foi realizada por meio de análises de marcas individuais, utilizando as metodologias de regressão linear e análise da máxima verossimilhança. Observou-se que o tipo de efeito predominante no controle genético da resist��ncia a cercosporiose foi o aditivo e para o controle genético da produção de grãos foi de dominância. Os marcadores microssatélites mais promissores para serem utilizados em estudos de seleção assistida para resistência a cercosporiose são umc2082 na posição 4.03 e umc1117 na posição 4.04 e para produção de grãos, umc1042 e umc1058 nas posições 2.07 e 4.11.

A estrutura genética de Aspidosperma polyneuron Muell Arg. (Apocynaceae)foi estudada utilizando a análise de marcadores microssatélites, nas localidades de Bauru,Gália, Avaré, Piracicaba, Valinhos, Teodoro Sampaio, Botucatu, Porto Ferreira, municípiosdo Estado de São Paulo, e Selvíria (Mato Grosso do Sul) onde foram coletadas folhas paraextração de DNA da população de cada local. Foram obtidos sete locos polimórficos e quatromonomórficos. Analisando os locos polimórficos, observou-se que o número de alelosvariou de dois a seis, que demonstraram uma alta heterozigosidade (ho = 0,5209). Em oitopopulações estudadas, os coeficientes de fixação f foram negativos com média de -0,0173 dasnove populações e a fixação total F foi 0,1034, enquanto o valor de coancestralidade θ p entrepopulações foi 0,1187. Foram também obtidos valores de fixação dentro de populações FIS(-0,0669), fixação total FIT (0,0747) e fixação genética entre populações com FST (0,1343) eGST (Hedrick) (0,4875). O fluxo gênico médio obtido Nm foi 1,6121. Exibe estrutura genéticatípica de espécie alógama, com baixo coeficiente de endogamia e alta heterozigosidade, comisolamento entre populações. A população Piracicaba indicou a maior erosão genética eisolamento; as outras populações ainda mostram a variabilidade original para coletas visandoà conservação e melhoramento genético.The genetic structure of Aspidosperma polyneuron Muell Arg. (Apocynaceae)was studied with SSR marker analysis, in Bauru, Gália, Avaré, Piracicaba, Valinhos, TeodoroSampaio, Botucatu, Porto Ferreira (São Paulo State cities), and Selvíria city (Mato Grosso doSul State), where leaves were collected for extracting DNA from the population of each site.Seven polymorphic and four monomorphic loci were obtained. Analyzing polymorphic loci,allele number ranged from two to six alleles, and showed high heterozigosity (ho = 0.5209).In eight populations the endogamy inbreeding coefficient f was negative, the nine populationsaverage was -0.0173, and total inbreeding coefficient F was 0.1034, meanwhile the coancestryvalue θ p among populations was 0.1187. Values of fixation within population FIS (-0.0669),total inbreeding FIT (0.0747), genetic fixation among populations with FST (0.1343) andGST (Hedrick) (0.4875) index were also obtained. The average gene flow Nm was 1.6121.It displays genetic structure typical of allogamous species with low inbreeding coefficientand high heterozygosity, with isolation between populations. Piracicaba population showedthe greatest genetic erosion and isolation, the other populations still remain the originalvariability for collections aiming conservation and breeding.

O objetivo deste trabalho foi investigar a diversidade, a estrutura genética e o tamanho efetivo, retido em um banco de germoplasma, de duas populações de Myracrodruon urundeuva Fr. All. (aroeira), procedentes de Aramina-SP e Selvíria-MS. As populações foram avaliadas a partir da amostragem de 25 progênies de polinização aberta de cada população. De cada progênie, 17 a 20 indivíduos foram amostrados e genotipados para oito locos microssatélites. Os maiores valores para o número total de alelos (At), número médio de alelos por loco (A), número efetivo de alelos (Ae), heterozigosidade observada (H0) e esperada (He) foram detectados na população Selvíria (At = 105, A = 13,13, Ae = 3,98, H0 = 0,669 e He = 0,749), enquanto Aramina teve At = 94, A = 13,75, Ae = 3,10, H 0 = 0,535 e He = 0,678. A diferenciação nas frequências alélicas das duas populações, com relação ao pólen cruzado (0,159) e do óvulo (0,235), indica que cerca de 84% e 77%, respectivamente, da diversidade genética está dentro das populações. O coeficiente médio de coancestria foi maior (Selvíria Θ = 0,165, Aramina Θ = 0,169) e o tamanho efetivo médio das progênies (Selvíria Ne(v) = 3,04, Aramina Ne(v) = 2,69) foi menor do que o esperado em progênies de populações panmíticas (Θ = 0,125, Ne(v) = 4). O tamanho efetivo total retido no banco ex situ foi estimado em 67,5 na população Selvíria e 71,1 na população Aramina, valores menores do que o requerido (Ne = 150) para a conservação de populações em curto prazo. Entretanto, as duas populações apresentaram alta diversidade genética, o que as qualifica para serem utilizadas em programas de conservação e melhoramento genético da espécie, desde que seja aumentado o tamanho efetivo populacional conservado ex situ.