65 research outputs found
Characterization of diversity and genetic structure in natural populations of Stryphnodendron adstringens (Mart.) Coville by means of allozyme markers
Recebido para publicação em 21/08/2012 Aceito para publicação em 08/10/2013 RESUMO: O S. adstringens, árvore tĂpica do Cerrado, tem sido explorada visando suas propriedades medicinais e tanantes. Em razĂŁo do ainda incipiente conhecimento genĂ©tico da espĂ©cie, este trabalho teve como objetivo caracterizar a diversidade e a estrutura genĂ©tica de S. adstringens por meio de marcadores aloenzimáticos. Foram coletadas sementes em cinco mesorregiões brasileiras, sendo amostrados 627 indivĂduos divididos em 16 populações localizadas nos Estados de Minas Gerais e Goiás. Foram testados 14 sistemas isoenzimáticos; destes, sete foram polimĂłrficos com o total de 10 locos e 28 alelos. O valor de diversidade genĂ©tica mĂ©dia (H) foi 0,226, a proporção mĂ©dia de locos polimĂłrficos (P) foi 68,75, o nĂşmero mĂ©dio de alelos por loco polimĂłrfico (AP) foi 2,65 e o nĂşmero efetivo de alelos (A e ) foi igual a 1,29. Resultados do Ăndice de fixação total (F= 0,003), do Ăndice de fixação dentro de populações (f = -0,114) e, da medida de diferenciação genĂ©tica (θ =0,105) foram nĂŁo significativos, indicando a inexistĂŞncia de estruturação genĂ©tica. Na análise de agrupamento (UPGMA) foram observados dois grupos principais, o primeiro formado pela população do Parque Estadual (PE) do Rio Preto (MG), e outro, formado pelas demais populações. Se excluĂda a população do PE do Rio Preto das análises, G ST Ă© drasticamente reduzido de 0,077 para 0,026. Assim, aproximadamente 2/3 do valor total de G ST verificado em S. adstringens foi devido Ă variação entre a população do PE do Rio Preto e as demais populações. De modo geral, os valores H e P observados em S. adstringens sĂŁo compatĂveis aos constatados em árvores tropicais comumente distribuĂdas. Por outro lado, excluindo a população do PE do Rio Preto, o valor da medida de diferenciação genĂ©tica G ST foi menor que o verificado em árvores tropicais nativas e pinheiros de zonas temperadas. A semelhança entre populações avaliadas indica que o fluxo gĂŞnico ainda Ă© alto o suficiente para prevenir a diferenciação genĂ©tica, pelo menos em nĂvel local. Palavras-chave: locos aloenzimáticos, diversidade genĂ©tica, barbatimĂŁo, plantas medicinais. ABSTRACT: Characterization of the diversity and genetic structure in natural populations of Stryphnodendron adstringens (Mart.) Coville by means of allozyme markers. The S. adstringens, a typical Cerrado (Brazilian savannah) tree, is used because of its medicinal and tanning properties. Because of the still incipient genetic knowledge of the species, the objective of this work was to characterize the diversity and genetic structure of S. adstringens by using allozyme markers. Seeds were collected in five Brazilian mesoregions, in which 627 individuals in 16 populations in the states of Minas Gerais and Goiás were sampled. Fourteen isoenzyme systems were assessed, out of which seven were polymorphic with a total of 10 loci and 28 alleles. Average genetic diversity (H) was 0.226, average proportion of polymorphic loci (P) was 68.75, average number of alleles per polymorphic locus (AP) was 2.65 and effective number of alleles (A e ) was equal to 1.29. The results of total fixation index (F= 0.003), within population fixation index (f =-0.114) and genetic differentiation measure (θ =0.105) were not significant, which shows the inexistence of genetic structure. Two principal groups were found in the cluster analysis (UPGMA), where the first one was formed by the population of State Park (PE) of Rio Preto (MG) and the other, by the other populations. If the population of PE of 12_102 217 Rev
Soybean Breeding Aiming at increasing Productivity and Root-Knot Nematode Resistance
In Brazil, the root-knot nematode (Pratylenchus brachyurus) has gained importance, whatever because of the damage caused to soybean crops or because of its broad dispersion and incidences in producing areas. Therefore, this invention aimed at developing a new cultivar resistant to the major soybean diseases as well as to the root-knot nematode. As a result, we developed a soybean cultivar designated UFUS 8301. Generations were advanced by the single seed descent method. Value for Cultivation and Use assays were carried out during a 3-year period (2010/13). Distinctness, uniformity, and stability experiments were carried out during a 2-year period (2011/13). We used the reproduction factor (RF) statistics to assess damage and reproductive potentials of P. Brachyurus; analysis of variance tested differences between means. We accepted the null hypothesis there was no difference between UFUS 8301 and the parameter of resistance Crotalaria spectabilis. UFUS 8301 was found distinct from any other cultivar, homogeneous to the descriptors that had identified it and stable through generations. UFUS 8301 presented 19% oil and 39% protein on the seeds, and yield (3687.5 kg ha-1) above Brazilian national average
Induction of Plasmodium falciparum-Specific CD4+ T Cells and Memory B Cells in Gabonese Children Vaccinated with RTS,S/AS01E and RTS,S/AS02D
The recombinant circumsporozoite protein (CS) based vaccine, RTS,S, confers protection against Plasmodium falciparum infection in controlled challenge trials and in field studies. The RTS,S recombinant antigen has been formulated with two adjuvant systems, AS01 and AS02, which have both been shown to induce strong specific antibody responses and CD4 T cell responses in adults. As infants and young children are particularly susceptible to malaria infection and constitute the main target population for a malaria vaccine, we have evaluated the induction of adaptive immune responses in young children living in malaria endemic regions following vaccination with RTS,S/AS01(E) and RTS,S/AS02(D). Our data show that a CS-specific memory B cell response is induced one month after the second and third vaccine dose and that CS-specific antibodies and memory B cells persist up to 12 months after the last vaccine injection. Both formulations also induced low but significant amounts of CS-specific IL-2(+) CD4(+) T cells one month after the second and third vaccine dose, upon short-term in vitro stimulation of whole blood cells with peptides covering the entire CS derived sequence in RTS,S. These results provide evidence that both RTS,S/AS01(E) and RTS,S/AS02(D) induced adaptive immune responses including antibodies, circulating memory B cells and CD4(+) T cells directed against P. falciparum CS protein.ClinicalTrials.gov NCT00307021
Carcass physical composition and meat quality of holstein calves, terminated in different finishing systems and slaughter weights
Perfil de ácidos graxos de cadeia longa e qualidade da carne de novilhos terminados em confinamento com diferentes nĂveis de monensina sĂłdica na dieta
- …