ABSTRACT Background: The objective of this study was the genetic characterization of remaining populations of the species Paratecoma peroba occurring in fragments of the Atlantic Forest, by estimating parameters of diversity and genetic structure. The study was carried out in two forest fragments, the Atlantic Forest Environmental Education Pole (area 1) and the Pacotuba National Forest (area 2), where 93 adult trees were identified. Results: Ten Inter Simple Sequence Repeats (ISSR) primers were used in genotyping, obtaining 112 amplified bands with 87.5% polymorphism. The genetic diversity estimated for the populations from the Nei (H*) and Shannon (I*) indices was higher for area 1. For the joint data, moderate genetic diversity was observed, referring to the average values of 0.26 and 0.40, obtained for the H* and I* indices, respectively. Molecular variance analysis resulted in moderate differentiation between populations (Φ ST = 0.143), while gene flow analysis (N m = 6.69) revealed the occurrence of similar alleles between them. However, the predominance of a single genetic group in area 2, revealed from Bayesian approach, indicates that its genetic structure, possibly generated by the current scenario of fragmentation of the Atlantic Forest and the distancing of populations, affecting the contemporary gene flow. Conclusion: Despite the moderate genetic diversity of the species for the area 2 population, actions toward inclusion of seedlings obtained from seeds from neighboring fragments, including area 1, and the increase in the connectivity of forest fragments through ecological corridors, could assist in augmenting its genetic variation.

Resumo Espécies de plantas que mostram padrão gregário de distribuição e endemismo na Floresta Atlântica, como Dorstenia elata, são particularmente sensíveis aos efeitos da perda da diversidade genética. Considerando isso, objetivou-se com este trabalho quantificar a diversidade genética em populações nativas dessa espécie em um remanescente da Mata Atlântica. A amostra incluiu três subpopulações de indivíduos e a caracterização molecular foi realizada com doze primers ISSR. As análises intrapopulacionais foram baseadas no cálculo do índice de Shannon; a heterozigosidade total esperada e a matriz de distâncias entre pares de indivíduos também foram calculadas. O dendrograma de agrupamento obtido evidenciou a formação de dois grupos. As investigações interpopulacionais foram baseadas na análise de variância molecular e na estimativa do fluxo gênico. Os resultados demonstram que um grupo compreendeu os genótipos de duas subpopulações, e o outro continha exclusivamente os genótipos de uma terceira subpopulação. A maior variabilidade genética foi observada dentro e não entre populações, indicando que a distância geográfica e a estrada que divide as populações estudadas não estão causando perda de diversidade genética.

Abstract Plant species that show gregarious spatial distribution and endemism to the Atlantic Forest, such as Dorstenia elata, are particularly sensitive to the effects of genetic diversity loss. In the present study, we aimed to quantify the genetic diversity in native populations of this species in an Atlantic Forest remnant. The sample included three aggregates of individuals, and molecular characterization was performed with twelve ISSR primers. Intrapopulation analyses were based on the calculation of the Shannon index; total expected heterozygosity and the matrix of distances between pairs of individuals were also calculated. The obtained grouping dendrogram evinced the formation of two groups. Interpopulation investigations were based on the analysis of molecular variance and the estimate of historical gene flow. The results demonstrate that one group comprised the genotypes from two subpopulations, and the other contained exclusively the genotypes of a third subpopulation. The greatest genetic variability was observed within rather than among populations, indicating that the geographical distance and the road that divides the studied populations are not causing loss of genetic diversity.

ABSTRACT: The evaluation of diversity and genetic structure allows us to verify with precision the effect of evolutionary and anthropic processes on species. The objective of this research was to evaluate the divergence and the genetic structure of two natural populations of Dalbergia nigra, using molecular markers Inter Simple Sequence Repeats (ISSR). Leaf samples were collected from two populations, located in the National Forest of Pacotuba and the Private Natural Heritage Reserve of Cafundó. Eight ISSR primers were used, which resulted in 97 bands, with 68.04% of polymorphism. Based on the joint data, the values of 0.33 for the Nei index (H*) and 0.50 for the Shannon index (I*) indicated moderate to high genetic diversity, being influenced by the presence of genetically dissimilar individuals in the National Forest of Pacotuba. Most of the genetic divergence was intrapopulational (85.96%), with moderate differentiation between populations (ΦST = 0.1404). The estimated historical gene flow between the fragments was low (Nm = 3.21) when compared with results from other tree species, and the genetic structuring analysis separated the populations into two groups, corresponding to the two populations evaluated. The results indicate a small genetic share among populations, however, populations are becoming structured. The satisfactory levels of genetic diversity benefit the use of the trees as matrixes for programs of restoration and recovery of degraded areas, connectivity of landscapes, and sustainable use of forest resources.

ABSTRACT Although a species’ sexual system may influence the genetic diversity of its populations in their natural environment, there have been few such studies involving indigenous species of the Atlantic Forest. Here we study Myrsine coriacea, a dioecious tree widely used in reforestation programs despite a lack of information about its natural interpopulation genetic variation. To address this knowledge gap, intra- and interpopulation genetic diversity were measured for male and female individuals of ten natural populations using ISSR markers. Greater intrapopulation genetic diversity indicated interpopulation gene flow, regardless of isolation and distance between populations. Multivariate analyses detected significant differences in genetic diversity between populations, but not between males and females, which indicates that genetic diversity did not differ between the two sex morphs. Distance between populations was unrelated to genetic diversity. Myrsine coriacea has not experienced a loss of genetic variability despite the characteristic segregated spatial distribution of its populations. These results suggest that obligatory cross-pollination and dispersal by birds may be important mechanisms for the maintenance of genetic diversity in natural populations of M. coriacea.

Abstract The objective of this work was to map QTL for agronomic traits in a Brazilian soybean population. For this, 207 F2:3 progenies from the cross CS3035PTA276-1-5-2 x UFVS2012 were genotyped and cultivated in Viçosa-MG, using randomized block design with three replications. QTL detection was carried out by linear regression and composite interval mapping. Thirty molecular markers linked to QTL were detected by linear regression for the total of nine agronomic traits. QTL for SWP (seed weight per plant), W100S (weight of 100 seeds), NPP (number of pods per plant), and NSP (number of seeds per plant) were detected by composite interval mapping. Four QTL with additive effect are promising for marker-assisted selection (MAS). Particularly, the markers Satt155 and Satt300 could be useful in simultaneous selection for greater SWP, NPP, and NSP.

Marcadores microssatélites originalmente desenvolvidos para Pitcairnia albiflos Herb. e Pitcairnia geysksii L.B.Sm. foram testados para amplificação heteróloga do genoma de cinco outras espécies de Bromeliacea. Dos treze pares de primers avaliados, dez (76,9%) geraram resultados positivos para algumas das espécies em estudo. O número de alelos polimórficos por loco variou entre dois e quatro para a maioria das espécies. Os valores de Ho variaram entre zero em Pitcairnia flammea Lindl. (PaA05), Aechmea ramosa Mart ex Schult & Schult e Billbergia horrida Regel (PaC05) e um para Billbergia euphemiae E. Morren (PaA05, PaA10, PaC05 e PaD07). Este estudo demonstrou que marcadores microssatélites desenvolvidos para P. albiflos e P. geysksii mostraram-se eficientes para amplificação heteróloga de amostras de DNA de Pitcairnia flammea, Aechmea nudicaulis (L.) Griseb., Aechmea ramosa, Billbergia horrida e Billbergia euphemiae, validando a transferibilidade destes marcadores para espécies das subfamílias Pitcairnioideae e Bromelioideae.

Microsatellite markers previously developed for Pitcairnia albiflos Herb. and Pitcairnia geysksii L.B.Sm. were used in cross-amplification tests of five other Bromeliaceae species. Ten (76.9%) out of the 13 evaluated pair of primers had positive results for some of the species tested. The number of polymorphic alleles ranged between two and four in most species. Ho values ranged between zero, in Pitcairnia flammea Lindl. (PaA05), Aechmea ramosa Mart ex Schult & Schult and Billbergia horrida Regel (PaC05), and one in Billbergia euphemiae E. Morren (PaA05, PaA10, PaC05 and PaD07). This study showed that microsatellite markers developed for P. albiflos and P. geysksii effectively amplified the DNA samples of Pitcairnia flammea, Aechmea nudicaulis (L.) Griseb., Aechmea ramosa, Billbergia horrida and Billbergia euphemiae, validating the transferability of these markers to species of the Pitcairnioideae and Bromelioideae subfamilies.

O objetivo deste trabalho foi detectar e mapear locos de caracteres quantitativos (QTL) que afetam os conteúdos de proteína e óleo em soja (Glycine max L. Merr.). Plantas F2, derivadas do cruzamento entre a linhagem CS3032PTA276 e a variedade UFVS2012, foram cultivadas em casa de vegetação e forneceram as folhas para extração e análise de DNA. Quarenta e oito marcadores microssatélites (SSR) polimórficos foram avaliados na população F2. A avaliação dos fenótipos foi realizada em 207 famílias das progênies F2:3, em um delineamento em blocos ao acaso, com três repetições, conduzido em Viçosa, MG, em 2006. Foram detectados quatro QTL associados ao conteúdo de proteína, nos grupos de ligação D1a, G, A1, e I, e três QTL associados ao conteúdo de óleo, nos grupos A1, I e O. A variação fenotípica explicada pelos QTL variou de 6,24 a 18,94% e 17,26 a 25,93%, respectivamente, para os conteúdos de proteína e óleo. Foram detectados novos QTL associados aos conteúdos de proteína e óleo, além dos previamente relatados em outros estudos. Regiões distintas das atualmente conhecidas podem estar envolvidas no controle genético do teor de proteína e óleo na soja.

The objective of this study was to detect and map quantitative trait loci (QTL) affecting soybean (Glycine max L. Merr.) protein and oil contents. F2 plants, derived from the cross between the CS3032PTA276 line and the variety UFVS2012, were grown in a greenhouse and provided the leaves for DNA extraction and analysis. Forty-eight polymorphic microsatelite markers (SSR) were evaluated in the F2 population. Evaluation of the phenotype was performed in 207 families from F2:3 progenies, in a complete block design with three replicates, carried out in Viçosa, MG, Brazil, in 2006. Four QTL associated with protein content, in linkage groups D1a, G, A1, and I, and three QTL for oil content in groups A1, I and O were identified. Phenotypic variation for protein and oil explained by QTL ranged from 6.24 to 18.94% and 17.26 to 25.93%, respectively. New QTL associated with protein and oil contents were detected, besides those previously reported in other studies. Other regions may be involved in the genetic control of protein and oil contents in soybean besides those already known.

Os objetivos deste trabalho foram detectar QTL relativos ao conteúdo de proteína, em soja cultivada em dois ambientes tropicais divergentes, e construir um mapa genético para o conteúdo de proteína em genótipos adaptados a condições tropicais. Foram usadas 118 linhagens recombinantes endogâmicas de soja, obtidas do cruzamento entre as cultivares BARC 8 e Garimpo. A população de linhagens recombinantes endogâmicas foi cultivada em dois ambientes contrastantes: Cascavel, PR, e Viçosa, MG (24º57'S, 53º27'W; e 20º45'S, 42º52'W, respectivamente). Sessenta e seis pares de iniciadores SSR e 65 iniciadores RAPD apresentaram fragmentos polimórficos que segregaram à proporção de 1:1. Foram obtidos 30 grupos de ligação pouco saturados, com 90 marcadores, além de 41 marcas não ligadas. Para as famílias cultivadas em Cascavel, três QTL foram mapeados nos grupos de ligação C2, E, e N, que explicaram 14,37, 10,31 e 7,34% da variação fenotípica do conteúdo de proteína, respectivamente. Para as famílias cultivadas em Viçosa, dois QTL foram mapeados nos grupos de ligação G e #1, que explicaram 9,51 e 7,34% da variação fenotípica do conteúdo de proteína. Com base na média dos dois ambientes, dois QTL foram identificados: um no grupo de ligação E (9,90%) e outro no grupo L (7,11%). Genótipos com maior estabilidade devem ser uados em trabalhos futuros, para a detecção de QTL com efeitos consistentes, em diferentes ambientes.

The objectives of this study were to detect quantitative trait loci (QTL) for protein content in soybean grown in two distinct tropical environments and to build a genetic map for protein content. One hundred eighteen soybean recombinant inbred lines (RIL), obtained from a cross between cultivars BARC 8 and Garimpo, were used. The RIL were cultivated in two distinct Brazilian tropical environments: Cascavel county, in Paraná, and Viçosa county, in Minas Gerais (24º57'S, 53º27'W and 20º45'S, 42º52'W, respectively). Sixty-six SSR primer pairs and 65 RAPD primers were polymorphic and segregated at a 1:1 proportion. Thirty poorly saturated linkage groups were obtained, with 90 markers and 41 nonlinked markers. For the lines cultivated in Cascavel, three QTL were mapped in C2, E and N linkage groups, which explained 14.37, 10.31 and 7.34% of the phenotypic variation of protein content, respectively. For the lines cultivated in Viçosa, two QTL were mapped in linkage groups G and #1, which explained 9.51 and 7.34% of the phenotypic variation of protein content. Based on the mean of the two environments, two QTL were identified: one in the linkage group E (9.90%) and other in the group L (7.11%). In order for future studies to consistently detect QTL effects of different environments, genotypes with greater stability should be used.