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Goncalves L.O.,Federal University of Sergipe | Pinheiro J.B.,University of Sao Paulo | Zucchi M.I.,Polo Regional Of Desenvolvimento Tecnologico Do Centro Sul | Silva-Mann R.,Federal University of Sergipe
Revista Ciencia Agronomica

The coral tree (Erythrina velutina Willd.), popularly known in Brazil as mulungu, presents various pharmacological properties and although extremely scarce, can be found in regions of the State of Sergipe, Brazil. Due to economic interests, producing information in order to set up plans for its conservation and sustainable exploitation becomes essential. The objective of this work was to characterize individuals of Erythrina velutina by means of ISSR markers. In order to do this, 40 individuals were studied from three locations in the State of Sergipe (The town of Pinhão-Caatinga; The towns of Santana do San Francisco and São Cristóvão-Atlantic Forest). In total, 149 loci from 11 ISSR primers were obtained and evaluated. The minimum number of loci for the study of diversity in E. velutina was 117, agreeing with Kruskal's stress value. Spatial genetic structuring is seen in the population from Santana, but the population from Pinhão lacks this structuring; its individuals are distributed randomly, compromising sustainability over time and therefore requiring immediate action for its conservation and restoration. Source

Silvestrini M.,University of Campinas | Pinto-Maglio C.A.F.,Instituto Agronomico Of Campinas | Zucchi M.I.,Polo Regional Of Desenvolvimento Tecnologico Do Centro Sul | Dos Santos F.A.M.,University of Campinas

Despite the recent advances in plant population genetic studies, the lack of information regarding pedigree, ploidy level, or mode of inheritance for many polyploids can compromise the analysis of the molecular data produced. The aim of this study was to examine both microsatellite and cytogenetic characteristics of the pioneer tree Croton floribundus Spreng. (Euphorbiaceae) to test for the occurrence of polyploidy in the species and to evaluate its implications for the appropriate use of SSR markers. Seven microsatellite markers were developed and screened for 62 individuals from a semi-deciduous tropical forest in Brazil. Chromosome number, meiotic behavior, and pollen viability were evaluated from male flower buds. All SSR loci were highly polymorphic. The number of bivalents observed in meiosis n = 56 (2n = 8× = 112) and the maximum number of alleles per individual (Ni = 8) demonstrated the occurrence of polyploidy in C. floribundus. The normal meiotic pairing and the high pollen viability suggested that C. floribundus is a regular and stable polyploid, most likely an allopolyploid. The combined SSR and cytogenetic data provided new evidence on the origin and evolution of the species as well as assured the accurate use of SSR loci for population genetic studies of the polyploid pioneer species. © 2013 Published by NRC Research Press. Source

Silvestrini M.,University of Campinas | McCauley D.E.,Vanderbilt University | Zucchi M.I.,Polo Regional Of Desenvolvimento Tecnologico Do Centro Sul | Santos F.A.M.,University of Campinas
Forest Ecology and Management

Pioneer tree species exhibit life-cycle characteristics and population structures that are mainly affected by natural or human disturbances. In primary forests, demographic dynamics of pioneer species may resemble those defined for a metapopulation. In early successional forests, the patterns of establishment, survival and reproduction are mainly determined by microclimate and biota modifications of the site after the human disturbance. The aim of this study was to investigate how the ecological processes and the population genetic factors associated with disturbances can affect the genetic diversity and structure of populations of a pioneer tree species: Croton floribundus Spreng. (Euphorbiaceae). Nuclear and chloroplast microsatellite markers were examined in plants of two size classes sampled in four gaps of primary forest and four sub-areas of early successional forest. Despite presenting similar genetic diversity levels, the genetic diversity was distributed differently between forests. The combined effects of seed dispersal and colonizations (and extinctions) were determinants of the fine-scale genetic structure of C. floribundus. The main finding was that human disturbances seem to boost the influence of founder effects in populations of a species with limited seed dispersal. Results suggested that gene flow by pollen was responsible for maintaining the genetic diversity within populations of C. floribundus in both forests, but in the early successional forest, gene flow by seeds was equally important. We conclude that gap dynamics, colonization, and pollen and seed dispersal affect the genetic diversity and structure of the pioneer species depending mainly on the number of colonizers, the number of source populations, the gene flow rates, and the level of human disturbance. © 2015 Elsevier B.V. Source

Melo M.F.V.,Sao Paulo State University | Goncalves L.O.,Secretaria Municipal de Agricultura e Desenvolvimento Economico | Rabbani A.R.C.,Instituto Federal Of Educacao | Alvares-Carvalho S.V.,Federal University of Sergipe | And 3 more authors.
Genetics and Molecular Research

The goal of this study was to characterize the structure of two natural populations of the coral tree using RAPD and ISSR markers. The study evaluated all individuals in two different areas in the northeastern region of Brazil: the first was in the riparian area, 10 km x 100 m along the edge of the lower São Francisco River, and the second was in the municipality of Pinhão, in a semiarid region between the municipalities of Neópolis and Santana do São Francisco. We used all the coral trees present in those two areas (37 individuals). The results of the RAPD and ISSR markers were highly congruent, supporting the reliability of the techniques used. Similarity was estimated using the Jaccard arithmetic complement index. A dendrogram was constructed using the unweighted pair group method with arithmetic mean cluster algorithm, and the robustness of the data was bootstrapped with 5000 replicates. A principal coordinate analysis was performed on the basis of Jaccard coefficients. The total genetic variation observed was 21%, corresponding to the variation between the populations, and 79% of the variation was observed within the populations. © FUNPEC-RP. Source

Facanali R.,Instituto Agronomico IAC | Facanali R.,Sao Paulo State University | Colombo C.A.,Instituto Agronomico IAC | Teixeira J.P.F.,Instituto Agronomico IAC | And 3 more authors.
Industrial Crops and Products

The present work aimed to characterize the chemical composition of essential oils and genetic diversity of three native populations of Ocimum selloi collected in Brazil southern and southeastern. Thus, with the proposals to subsidize genetic improvement programs for the species preservation and commercial application of the essential oil.A total of 60 samples from Iporanga and Piquete counties (State of São Paulo) and Adrianópolis county (State of Paraná) were analyzed by RAPD - genetic polymorphism - and GC-MS - chemical composition of essential oils. The data showed that the variation of the chemical composition of the essential oils of the samples was influenced by geographical region and genetic factors. The Piquete population was more homogeneous with respect to factors evaluated, and presented germacrene D, elemicin, trans-α-bergamotene, and bicyclogermacrene as the major components. Populations of Adrianópolis and Iporanga showed strong variability probably due to the gene flow between these populations, because they are geographically close. Most samples of these two regions had as major substances elemicin, β-selinene, and β-4-copaen-α-ol. The results showed a great genetic and chemical divergence among and inside the populations between, being the diversity inside the populations bigger than among populations. The oils presented potential for commercial use in the manufacture of veterinary, pharmaceutical, and agricultural products. © 2015 Elsevier B.V. Source

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