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 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. Index terms: Glycine max, linkage map, molecular markers, recombinant inbred lines, quantitative trait loci. Mapeamento de QTL quanto ao conteúdo de proteína em soja cultivada em dois ambientes tropicaisResumo -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.Termos de indexação: Glycine max, mapa de ligação, marcador molecular, l...
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. Bromeliads are greatly represented in the Atlantic Forest, although many species are threatened with extinction owing to habitat fragmentation and intense extraction for ornamental purposes. Therefore, it is necessary to conduct studies generating knowledge about genetic 15893 Genetic variability in Pitcairnia flammea (Bromeliaceae) ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (4): 15892-15901 (2015) diversity and the distribution of this diversity among and within natural populations to establish conservation strategies. These studies can be performed with the use of molecular markers. Molecular markers are advantageous for studies of natural populations, for conservation programs, and to aid in properly classifying plant species. This study aimed to evaluate the genetic diversity among and within natural populations of Pitcairnia flammea, occurring in three fragments of the Atlantic Forest in the southern State of Espírito Santo through the use of inter-simple sequence repeat (ISSR) markers. DNA samples from 55 individuals were amplified with 18 ISSR primers, generating 180 bands, 159 of which were polymorphic. The Shannon genetic diversity index ranged from 0.348 to 0.465, with an average of 0.412. The Bayesian approach for the molecular data indicated the existence of two genetic groups. Analysis of molecular variance indicated the existence of 90.3% diversity within the population and 9.74% among populations. The amount of genetic differentiation of populations was moderate (0.0974), indicating that gene flow rates may be enough to counteract the effects of genetic drift. Greater genetic variability found in population B indicates that this area is an important source of genetic variability.
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. Leaf samples were collected from individuals of these species in natural populations occurring in fragments of the Atlantic Forests, in Burarama, Cachoeiro de Itapemirim, ES. DNA of plant samples were extracted and purified using the cetyltrimethylammonium bromide (CTAB) extraction method, as described by Doyle & Doyle (1990).In order to improve the PCR result, the optimal annealing temperatures of each pair of primers to be tested were determined (between 48 and 56 °C). In all cases, microsatellite loci were amplified in a 15 µL volume containing 0.4 µM of each primer, 1 U Taq DNA polymerase, 0.1 mM of each dNTP, 1 × MgCl 2 -free reaction buffer (10 mM Tris-HCl pH 8.3 and 50 mM KCl), 2 mM MgCl 2 and 30 ng of template DNA.Amplifications were performed using a Techne TC-412 thermal cycler under the following conditions: 5 minutes denaturation at 94 °C followed by 30 cycles of 1 minute of initial denaturation at 94 °C, 1 minute of annealing temperature at 54 °C and 1 minute of extension at 72 °C, and elongation at 72 °C for 7 minutes.Amplified fragments were separated by electrophoresis on 2.5% agarose gel containing 0.02 ug/mL ethidium bromide, 1x TBE buffer (0.89 M Tris-HCl pH 8.3, 0.89 M boric acid and 0.02 M EDTA), at 110 volts for approximately three hours. Afterwards, the gels were photo graphed under UV light, using the gel documentation system Biolocus L PIX (Loccus Biotecnologia ® ). Gel electrophoresis was used to assess the number and size of amplified fragments, as well as polymorphism detection.Analyses of genetic variability at the microsatellite loci were done using the genotypes obtained for all five species of bromeliads evaluated in this study. The number of alleles per locus and the observed and expected heterozygosities under Hardy-Weinberg equilibrium were estimated. These analyses and the test for deviation from Hardy-Weinberg expectations were performed with Genes program (Cruz 2008).
Pitcairnia azouryi is a species of Bromeliaceae restricted to Atlantic Forest inselbergs of southeastern Brazil. Since the species was first described, populations of P. azouryi have been observed from three locations in the states of Rio de Janeiro and Espírito Santo. Here we report four new populations discovered after extensive fieldwork during a period of three years on 21 inselbergs in the states of Espírito Santo and Rio de Janeiro, Brazil. With the discovery of these four new populations from the inselbergs Pedra Lisa, Pedra do Jacu, Pedra Três Irmãs e Pedra Parada Cristal (all located in the State of Espírito Santo), the number of locations where P. azouryi is known to occur has increased to seven. The analysis of these new samples allowed the evaluation of within species morphological variation, compared to the protologue description of plant height and leaf dimensions. We classify Pitcairnia azouryi as endangered (EN). This classification is based on the species’ extension of occurrence (1,470 km2), area of occupancy (ca. 53 km2), number of known populations (7), and the fact that none of its occurrence sites are within a protected conservation areas.
Studies of genetic diversity in natural populations are important for the definition of conservation strategies, especially in populations reduced by processes of fragmentation and continuous forest extraction. Molecular markers stand out as interesting tools for these studies. The objective of this research was to characterize the diversity and genetic structure of Plathymenia reticulata (Fabaceae), occurring in two fragments of the Montana Semideciduous Forest in the southern of Espírito Santo State, Brazil, using inter-simple sequence repeat (ISSR) molecular markers. DNA samples from 149 individuals were analyzed using 10 ISSR primers, generating 156 fragments, of which 101 were polymorphic (64.74%). The individuals sampled were classified into three units: adult trees (A), a mixture of progenies (B), and young regenerating individuals (C). The number of loci used (N = 101) was greater than that established as optimal number (N = 88), indicating precision in analyses. The genetic diversity index of Nei (H' = 0.407) and the Shannon index (I = 0.594) were found to have high genetic diversity. Besides, through the diversity parameters evaluated, it was possible to confirm that in the areas of natural regeneration and progeny mix there is genetic diversity equivalent to that found in adults. The analysis of molecular variance indicated that most of the genetic variation is found within the groups (96.53%). Genetic differentiation among adult trees was low (Φ = 0.03) indicating that high gene flow rates (N = 12.70) are counteracting the effects of genetic drift. The data obtained allowed to evaluate the potential of adult trees as matrices for seed collection and to obtain seedlings with confirmed genetic variability.
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