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Detection of plasmid families carrying ESBL genes in clinical and environmental E. coli and K. pneumoniae isolates / Detektion av plasmidfamiljer som bär ESBL-gener i E. coli och K. pneumoniae isolerade från klinik och miljöNilsson, Johanna January 2019 (has links)
Extended Spectrum β-Lactamases (ESBLs) are produced by the Enterobacteriaceae bacterial family, mainly by E. coli and K. pneumoniae. As these species are some of the main causes of urinary tract infections and sepsis, ESBL-production is of major concern. Occurrence of ESBLs also gives rise to concern as it is increasing epidemically. This because the genes coding for ESBLs (i.e. bla-genes) are located on plasmids replicating and spreading the replicated copies independently. Plasmids replicate by replicons. Plasmids with the same replicon variant are grouped into the same plasmid family. The aim of this study was to detect plasmid families carrying bla-genes in E. coli and K. pneumoniae from clinical (n = 6) and environmental water (n = 22) isolates. Plasmid family prevalence was examined. Association between plasmid families and bla-genes was also examined. Plasmid families were detected by a PBRT kit (PCR Based Replicon Typing), a multiplex PCR kit that detected 30 replicons, whereof 27 replicons representing the 27 plasmid families in Enterobacteriaceae, and three novel replicons. The IncF plasmid family was the most prevalent for both species in both clinical and environmental isolates. IncF seemed to be prevalent for all examined ESBLs, but it was difficult to associate one bla-gene with one plasmid family as most isolates carried several bla-genes and several plasmid families. / Extended Spectrum β-Lactamases (ESBLs) produceras av bakteriefamiljen Enterobacteriaceae, främst av E. coli och K. pneumoniae. Eftersom dessa arter är bland de vanligaste orsakerna till urinvägsinfektioner och sepsis är ESBL-produktion ett allvarligt problem. ESBL är också oroande eftersom det sprids epidemiskt. Detta möjliggörs av att generna som kodar för ESBLs (s.k. bla-gener) ligger på plasmider, som replikerar och sprider de replikerade plasmidkopiorna självständigt. Plasmider replikeras som s.k. replikon. Plasmider med samma replikonvariant tillhör samma plasmidfamilj. Syftet med detta arbete var att detektera plasmidfamiljer som bär bla-gener i E. coli och K. pneumoniae isolerade från kliniska prov (n = 6) och miljöprov (n = 22) från Helge Å. Plasmidfamiljernas prevalens undersöktes, liksom sambandet mellan plasmidfamiljer och bla-gener. Plasmidfamiljerna detekterades med ett PBRT-kit (PCR Based Replicon Typing), ett multiplext PCR-kit som detekterade 30 replikon varav 27 replikon som representerar de 27 plasmidfamiljer som finns i Enterobacteriaceae och tre nya replikon. Plasmidfamiljen IncF var vanligast förekommande i båda arter i både kliniska isolat och miljöisolat. IncF verkade förekomma för alla undersökta typer av ESBL, men det var generellt svårt att förknippa en bla-gen med en plasmidfamilj, eftersom de flesta isolaten bar flera bla-gener och flera plasmidfamiljer.
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Incompatibilidade de medicamentos intravenosos e fatores de risco em pacientes críticos: coorte histórica / Incompatibility of intravenous medications and risk factors in critically ill patients: historical cohortGarcia, Julia Helena 30 June 2015 (has links)
Introdução: A incompatibilidade de medicamento resulta de um fenômeno físico-químico causado pela combinação de dois ou mais medicamentos na mesma solução ou misturados em um mesmo recipiente. Pode ser considerado um erro de medicação pelo potencial de comprometer negativamente o tratamento. Objetivo: Estimar a incidência de incompatibilidades potenciais de medicamentos administrados por via intravenosa e fatores associados em pacientes críticos. Método: Coorte retrospectiva conduzida com pacientes internados nas Unidades de Terapia Intensiva e Semi-intensiva do Hospital Universitário da Universidade de São Paulo. A amostra foi composta por 110 indivíduos adultos hospitalizados, por pelo menos 72 horas, nessas unidades e submetidos à terapia intravenosa. A incompatibilidade potencial de medicamento foi analisada em duplas de medicamentos, utilizando-se a ferramenta Trissel´s TM 2 Compatibility IV, através da base de dados Micromedex 2.0®. A variável dependente foi a ocorrência de incompatibilidade. As variáveis independentes foram idade, sexo, procedência, tipo de internação, tempo de permanência, SAPSII, índice de Charlson, carga de trabalho de enfermagem, condição de alta, modo de infusão, número de medicamentos prescritos e de prescritores. Na análise dos dados utilizaram-se os testes qui-quadrado de Pearson, Exato de Fisher, Kruskal-Wallis, modelo de análise de variância ANOVA e regressão logística, com significância de p 0,05. Resultados: A incidência de incompatibilidade potencial de medicamentos foi de 2,7%. Foram prescritos 72 tipos diferentes de medicamentos que formaram 565 duplas, destas, 44,9%, foram compatíveis e 8,8%, incompatíveis. O aparecimento de precipitação (50,0%) foi a alteração físico-química mais identificada, após as combinações via dispositivo em Y. Na frequência de aparecimento, as duplas de medicamentos incompatíveis formadas por fenitoína (32,0%), diazepam (14,0%), midazolam (10,0%) e dobutamina (8,0%) foram as mais identificadas. Cerca de 70% dos pacientes receberam medicamentos prescritos a critério médico, principalmente durante o período noturno. Os fatores de riscos associados à incompatibilidade foram procedência (RC: 1,506; IC: 0,327 - 6,934); tempo de permanência prolongado nas unidades (RC: 1,175; IC: 1,058 - 1,306); maior número de medicamentos prescritos (RC: 1,395; IC: 1,091 -1,784) e carga elevada de trabalho de enfermagem (RC: 1,060; IC: 1,010 -1,113). Conclusão: O número de medicamentos prescritos aos pacientes críticos, em decorrência da gravidade clínica, aumenta exponencialmente a ocorrência de incompatibilidade e, os expõe a graves consequências. Embora haja outros estudos que identifiquem as incompatibilidades potenciais, observa-se, no cotidiano das unidades críticas, a repetição de rotinas que comprometem a segurança do paciente. A incompatibilidade poderá ser teoricamente diminuída, quando houver ênfase nas medidas preventivas e na contínua educação da equipe multidisciplinar. / Introduction: Drug incompatibility results from a physicochemical phenomenon caused by the combination of two or more drugs in the same solution or mixed in a single container. It can be considered a medication error due to its potential to compromise the treatment. Objective: To estimate the incidence of potential incompatibilities of drugs administered intravenously and associated factors in critically ill patients. Methods: Retrospective cohort study conducted with patients in Intensive and Semi-intensive Care Units at the University Hospital of the University of São Paulo. The sample consisted of 110 adults hospitalized for, at least 72 hours, in these units and submitted to intravenous therapy. The potential drug incompatibility was analyzed in pairs of drugs, using the TM Trissel\'s 2 Compatibility IV tool through Micromedex 2.0® database. The dependent variable was the occurrence of incompatibility. The independent variables were age, gender, origin, type of admission, length of stay, SAPSII, Charlson index, nursing workload (NAS), discharge condition, infusion mode, number of prescription drugs and prescribers. To analyze the data we used the chi-squared Pearson tests, Fisher Exact test, Kruskal-Wallis, ANOVA model and logistic regression, with significance p 0.05. Results: The incidence of potential incompatibility of drugs was 2.7%. Seventy-two 72 different types of drugs were prescribed forming 565 pairs of which 44.9% were compatible and 8.8%, incompatible. The precipitation onset (50.0%) was most identified physical-chemical change after the combinations via device Y. In frequency of appearance, the pairs of drugs formed by phenytoin (32.0%), diazepam (14.0%), midazolam (10.0%) and dobutamine (8.0%) were the most identified. About 70% of the patients received prescription drugs to medical criteria, especially during the night. Risk factors associated with the incompatibility were origin (OR: 1.506; CI: 0.327 to 6.934); prolonged length of stay in the units (OR: 1.175; CI: 1.058 to 1.306); greater number of prescribed medications (OR: 1.395; CI: 1.091 -1.784) and high nursing workload (OR: 1.060; CI: 1.010 -1.113). Conclusion: The number of prescription drugs to critically ill patients, due to the clinical severity, exponentially increases the occurrence of incompatibility and exposes them to serious consequences. Although there are other studies that identify the potential incompatibilities, we observe, in the daily life of critical units, repeating routines that compromise patient safety. Incompatibility can be theoretically reduced when there is emphasis on preventive measures and continuous education of the multidisciplinary team
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Tribunal Penal Internacional e o direito interno brasileiroBueno, Luciana de Oliveira 01 August 2014 (has links)
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Previous issue date: 2014-08-01 / The International Criminal Court represented a major breakthrough in the international scenery, as the accountability of agents who commit extremely serious crimes because it was created in a permanent and complementary manner to national jurisdictions, respecting the principles of universality, complementarity, natural justice and independence. This Court, which differed from background experiences, for their essential characteristics, was structured in an organized way, giving the prosecutor the important investigative role, which greatly contributed to the achievement of the Court work. The Court's decisions, in turn, are uttered with the observance of the principles of legal reserve and prior criminal law, giving them greater legal certainty and fairness. However, what is observed is that the States that are committed to cooperate with the work of the Court, often do not contribute to the investigation or to implement the decisions of the Court, which has sparked many debates about the need to apply the law of force rather than the force of law. Another issue of great importance lies in the compatibility of the rules laid down in the Rome Statute with the Brazilian Federal Constitution, which, in some cases, apparently contrasts with our legal system. However, as it will be seen throughout this study, the problem of effectiveness slips in the very development of the countries involved in the conflict and the alleged incompatibilities exist in appearance only and do not constitute in reality / O Tribunal Penal Internacional representou um grande avanço no cenário
internacional, quanto à responsabilização de agentes que cometem crimes de
extrema gravidade, pois foi criado de forma permanente e complementar às
jurisdições nacionais, respeitando os princípios da universalidade,
complementaridade, juiz natural e independência. Esse Tribunal, que se
diferenciou das experiências antecedentes, por suas características essenciais,
foi estruturado de forma organizada, atribuindo ao Procurador o importante papel
investigativo, o que muito contribuiu para a concretização dos trabalhos da Corte.
As decisões do Tribunal, por sua vez, são proferidas com a observância dos
princípios da reserva legal e da anterioridade da lei penal, conferindo-lhes maior
segurança jurídica e imparcialidade. Entretanto, o que se observa é que os
Estados, que assumem o compromisso de cooperar com os trabalhos da Corte,
por muitas vezes não contribuem com a investigação ou para a execução das
decisões proferidas pelo Tribunal, o que tem suscitado diversos debates acerca
da necessidade da aplicação do direito da força em detrimento da força do direito.
Outra questão de grande relevo reside na compatibilidade das normas
previstas no Estatuto de Roma com a Constituição Federal brasileira, as quais,
em algumas hipóteses, aparentemente contrastam com nosso ordenamento
jurídico.
Contudo, como se verá no decorrer desse estudo, o problema da
efetividade resvala no próprio desenvolvimento dos países envolvidos nos
conflitos e as supostas incompatibilidades só existem na aparência e não se
configuram na realidade
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Breeding System Evolution and Pollination Success in the Wind-Pollinated Herb <i>Plantago maritima</i>Nilsson, Emil January 2005 (has links)
<p>In this thesis, I examined variation in sex expression and mating patterns in the sexually polymorphic, wind-pollinated herb <i>Plantago maritima</i>. With a combination of field studies, greenhouse experiments, and genetic analyses, I (a) examined factors influencing sex ratio variation in gynodioecious plants (in which hermaphrodites and females coexist), (b) discovered variation in breeding system, (c) investigated density-dependence of seed production, and (d) documented genetic variation within and among populations close to the northern range margin in Europe. </p><p>In a survey of 104 <i>P. maritima</i> populations, I documented considerable variation in sex ratio (range 0-70% females, median 6.3% females). As predicted, females were more frequently missing from small than from large populations, and the variance in sex ratio increased with decreasing population size. Among twelve populations sampled for seed production, the frequency of females was positively related to relative fecundity of females and negatively related to population size. The results suggest that the local sex ratio is influenced both by the relative fecundity of females and hermaphrodites, and by stochastic processes in small populations.</p><p>A comparative field study showed that plant fecundity decreased with increasing distance to nearest pollen donor both within and among populations in an archipelago in southern Sweden, where self-incompatibility was confirmed in controlled crosses. In contrast, plant fecundity was overall higher and was not density-dependent in the Skeppsvik archipelago in northern Sweden, where controlled crosses showed that plants are self-compatible. The results were consistent with the prediction that evolution of self-fertility should reduce density-dependence of pollination success.</p><p>I quantified the genetic structure within and among populations from eastern Sweden and western Finland based on variation at four polymorphic microsatellite loci. The genetic diversity was low in northern Sweden, which may be the result of a history of small population sizes and periods of frequent self-fertilization.</p>
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Breeding System Evolution and Pollination Success in the Wind-Pollinated Herb Plantago maritimaNilsson, Emil January 2005 (has links)
In this thesis, I examined variation in sex expression and mating patterns in the sexually polymorphic, wind-pollinated herb Plantago maritima. With a combination of field studies, greenhouse experiments, and genetic analyses, I (a) examined factors influencing sex ratio variation in gynodioecious plants (in which hermaphrodites and females coexist), (b) discovered variation in breeding system, (c) investigated density-dependence of seed production, and (d) documented genetic variation within and among populations close to the northern range margin in Europe. In a survey of 104 P. maritima populations, I documented considerable variation in sex ratio (range 0-70% females, median 6.3% females). As predicted, females were more frequently missing from small than from large populations, and the variance in sex ratio increased with decreasing population size. Among twelve populations sampled for seed production, the frequency of females was positively related to relative fecundity of females and negatively related to population size. The results suggest that the local sex ratio is influenced both by the relative fecundity of females and hermaphrodites, and by stochastic processes in small populations. A comparative field study showed that plant fecundity decreased with increasing distance to nearest pollen donor both within and among populations in an archipelago in southern Sweden, where self-incompatibility was confirmed in controlled crosses. In contrast, plant fecundity was overall higher and was not density-dependent in the Skeppsvik archipelago in northern Sweden, where controlled crosses showed that plants are self-compatible. The results were consistent with the prediction that evolution of self-fertility should reduce density-dependence of pollination success. I quantified the genetic structure within and among populations from eastern Sweden and western Finland based on variation at four polymorphic microsatellite loci. The genetic diversity was low in northern Sweden, which may be the result of a history of small population sizes and periods of frequent self-fertilization.
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An Investigation of the Exocyst Complex and its role in Compatible Pollen-pistil Interactions in ArabidopsisHaasen, Katrina Ellen 06 April 2010 (has links)
Compatible interactions between male gametophytes (pollen) and the female reproductive organ (pistil) are essential for fertilization in flowering plants. Recognition at a molecular level allows “compatible” pollen grains to adhere/germinate on the stigma while pollen grains from unrelated plant species are largely ignored. The exocyst is a large eight subunit complex that is primarily involved in polarized secretion or regulated exocytosis in eukaryotic cells where it functions to tether vesicles to the plasma membrane. Recent research has implicated one of the Exo70 family members, Exo70A1, in compatible pollen-pistil interactions in Arabidopsis and Brassica. The loss of Exo70A1 in Arabidopsis Col-0 stigmas leads to the rejection of compatible pollen producing a “female sterile” phenotype. Through my research I have demonstrated that, driven by a stigma-specific promoter, an RFP:Exo70A1 fusion protein rescues this defect in exo70A1-1 mutant and Exo70A1 is found to be localized to the plasma membrane at flower opening.
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An Investigation of the Exocyst Complex and its role in Compatible Pollen-pistil Interactions in ArabidopsisHaasen, Katrina Ellen 06 April 2010 (has links)
Compatible interactions between male gametophytes (pollen) and the female reproductive organ (pistil) are essential for fertilization in flowering plants. Recognition at a molecular level allows “compatible” pollen grains to adhere/germinate on the stigma while pollen grains from unrelated plant species are largely ignored. The exocyst is a large eight subunit complex that is primarily involved in polarized secretion or regulated exocytosis in eukaryotic cells where it functions to tether vesicles to the plasma membrane. Recent research has implicated one of the Exo70 family members, Exo70A1, in compatible pollen-pistil interactions in Arabidopsis and Brassica. The loss of Exo70A1 in Arabidopsis Col-0 stigmas leads to the rejection of compatible pollen producing a “female sterile” phenotype. Through my research I have demonstrated that, driven by a stigma-specific promoter, an RFP:Exo70A1 fusion protein rescues this defect in exo70A1-1 mutant and Exo70A1 is found to be localized to the plasma membrane at flower opening.
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Regulation of Self-Incompatibility by Endocytic TraffickingSchnabel, Jonathan 29 November 2013 (has links) (PDF)
Self-incompatibility is a genetic barrier by which a plant recognizes and rejects its own pollen while allowing pollen from more distantly related plants to germinate. In the Brassicacea family, it is controlled by a highly polymorphic locus called the S-locus, which contains the male and female determinants of self-incompatibility. The stigma expresses the female determinant of self-incompatibility, the plant receptor kinase (PRK) S-LOCUS RECEPTOR KINASE (SRK). In Brassica oleracea, SRK has a unique subcellular localization among PRK: the receptor is mostly localized in endosomes and to a lesser extent at the plasma membrane.We investigated the function of the endosomal localization of SRK in Arabidopsis thaliana. Firstly, we reintroduced self-incompatibility in Arabidopsis thaliana by expression of a functional SRK allele from Arabidopsis lyrata (a self-incompatible species). Secondly, we showed that a loss-of-function mutant of DYNAMIN-RELATED PROTEIN1A, a protein required for endocytosis, abolished self-incompatibility. Our results suggest that endocytosis is required for self-incompatibility, and that SRK may be signaling from endosomal compartments.
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Características dos doadores de medula óssea e seu impacto no desfecho dos pacientes submetidos a transplante alogênico no Hospital de Clinicas de Porto AlegrePaz, Alessandra Aparecida January 2015 (has links)
Introdução: O Transplante de Célula Tronco Hematopoiética (TCTH) é um tratamento potencialmente curativo para muitas desordens hematológicas. A disparidade HLA entre doador e receptor é um fator crítico para os resultados do TCTH. No entanto novas evidencias tem demonstrado que outros fatores como a fonte de célula tronco, o tipo de condicionamento e fatores relacionados aos doadores, entre eles o sexo, a idade e o status sorológico para Citomegalovirus (CMV) podem influenciar os desfechos do procedimento. Objetivo: Avaliar as características dos doadores de medula óssea e seu impacto nos desfechos do TCTH em um centro do Sul do Brasil. Métodos: Foram avaliadas retrospectivamente as características dos doadores como sexo, idade, presença de exposição previa ao CMV, incompatibilidade ABO e suas relações com a ocorrência de doença do enxerto contra hospedeiro (DECH) aguda e crônica, a mortalidade relacionada ao transplante (do inglês tumor related mortality – TRM) sobrevida livre de doença (SLD) e sobrevida Global (SG) em todos os pacientes submetidos a TCTH alogênico em um único centro durante o período de 1994 a 2012. Resultados: 347 pacientes foram incluídos na análise. O TCTH aparentado foi significativamente mais freqüente que o não aparentado (81.2 x 18.7), a mediana de idade foi de 34 (1-61) para os receptores e 33 (1-65) para os doadores. Na analise multivariada a presença de DECH agudo (33% vs 47%) p=0,04 e ter doadores mais idosos (>40 anos) foram associados a uma redução de SG em 5 anos (41% vs 52%) p=0,038. Ter um doador acima de 40 anos aumenta significativamente a incidência de DECH aguda (52% vs 65,8%) p=0,03 e crônica (60% vs 43%) p=0,015. O sexo do doador, presença de CMV e incompatibilidade ABO não tiveram influencia nos desfechos. Conclusão: Em um centro único avaliado receber um transplante de CTH de doadores acima de 40 anos aumenta a incidência de DECH aguda e crônica e influencia negativamente na SG. / Background: Hematopoietic Stem cell Transplantation (HSCT) is a curative treatment for many patients with hematological disorders. Donor – recipient genetic disparity, especially involving the HLA systems is a critical factor for HSCT outcome There are increasing evidences, however that other issues as source of stem cell, conditioning regimen, donor gender, age and CMV infection can affect HSCT outcomes. Objective: To study the influence of donor’s characteristics on the HSCT outcomes in a south Brazilian population subjected to allogeneic SCT in a single center. Methods: We retrospectively evaluated donor characteristics such as gender, age, CMV serologic status and ABO compatibility and its relation to the occurrence of acute and chronic graft versus host disease (GVHD), disease free survival (DFS) and overall survival (OS) in all patients submitted to related and unrelated allogeneic HSCT, performed between 1994 and 2012. Results: Overall 347 consecutives HSCT were included in this analysis. Related HSCT was significantly more frequent than unrelated (81.2% x 18.7%); donor and recipient median age were 34 (1- 61) and 33 (1-65), respectively. In the multivariate analyses, presence acute GVHD (33%vs 47%)p=0.04 ,with relative risk and donors older than 40 years old was associated with lower probability of OS in 5 years (41% vs 52%) p=0,038 and higher rate of acute (65.8%vs 52%) p=0.03 and chronic GVHD (43% vs 60%) p=0,015. Donor’s sex, CMV status, ABO incompatibility have not influenced 5-years survival. Conclusions: In a single center population of patients submitted to related and unrelated HSCT in southern Brazil donor older then 40 years of age is a factor negatively influencing HSCT outcome.
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Genotipagem de alelos S em macieira e sua utilização como ferramenta auxiliar ao melhoramento genético / Genotyping of S alleles in apple tree and its use as an auxiliary tool for genetic improvementBrancher, Thyana Lays 02 February 2017 (has links)
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Previous issue date: 2017-02-02 / PROMOP / CAPES / Due to the gametophytic self-incompatibility (GSI), the occurrence of cross-pollination
between genetically compatible plants is necessary for the naturally fructification of
apple trees (Malus domestica Borkh.). The GSI is governed by the multiallelic locus
called S, which encodes a family of RNases thats act on the pistil and prevents the
formation of the pollen tube when the S alleles presented in the pollen grain is the
same as that is presented in the diploid tissue of the pistil. From the identification of
the S alleles of plants of interest it is possible to guide the combinations between
parents to obtain segregant populations and to predict the efficiency of apple tree
genotypes when they are used as pollinators in commercial orchards. The objectives
of this dissertation were to validate the use of DNA markers in the identification of the
genetic constitution of the S locus of apple tree genotypes, as well as the definition of
pollinators genotypes to be adopted in commercial orchards, serving as an auxiliary
tool for the apple breeding. The study of the segregation of the S alleles carried out in
segregating populations of apple trees by DNA markers (Chapter 2); the locus S of
28 genotypes of apple trees were analyzed by DNA markers and the genetic
dissimilarity analysis was done based on the characterization of the same genotypes
for based on the minimum descriptors required for the protection of new cultivars
(Chapter 3); and the determination of the pollinators genotypes for three apple was
done based on the genotyping of the S alleles associated with cross testing (Chapter
4). In the study of segregation of S alleles in segregating populations, the progeny of
the cross between Fred Hough (S5S19) vs. Monalisa (S2S10) followed the expected
segregation ratio for genotype compatibility: 1:1:1:1. In the other population
evaluated, the same pair of S alleles, S3S5, were identified in both parents (M-11/01
and M-13/91), and the progeny showed the same genotype. In 26 of the 28
genotypes evaluated, both alleles S were identified, and in the remaining two
genotypes only one allele was identified in each genotype. The average dissimilarity
of the 28 genotypes obtained by the morphoagronomic characterization was 35 %.
Considering the total genetic compatibility between the genotypes and the five major
dissimilarities obtained, 15 crosses were suggested to increase the genetic base of
the Epagri's Genetic Apple Breeding Program. Regarding the selection of pollinators,
the field pollination tests did not show a significant difference between the cultivars
and their respective pollinators tested for characters the fruit set and seed number,
but when the S alleles present in each of the genotypes, were identified the presence
of semi-compatibility cases between them. This fact can be explain by the high
concentration of pollen grains applied on the pistil of the flowers on artificial
pollination, which may mask the existing semi-compatibility. Considering the results
obtained in this study, DNA markers can be used to identify the locus S genotype in
apple trees as an auxiliary tool to the Epagri's Genetic Apple Breeding Program, both
for the definition of combinations between parents for the formation of segregant
populations as to chose pollinators to fruit-producing cultivars to be adopted in
commercial orchards / Devido a autoincompatibilidade gametofítica (AIG), para a formação de frutos em
plantas de macieira (Malus domestica Borkh.) é necessária a ocorrência de
polinização cruzada entre plantas geneticamente compatíveis. A AIG é governada
pelo loco multialélico S, que codifica para uma família de RNases atuantes no pistilo
da planta e impede a formação do tubo polínico quando os alelos S presentes no
grão de pólen forem iguais àqueles presentes no tecido diploide do pistilo. A partir da
identificação dos alelos S de plantas de interesse é possível orientar as
combinações entre genitores para a obtenção de populações segregantes via
hibridações dirigidas e prever a eficiência de genótipos de macieira quando
utilizados como polinizadores em pomares comerciais. Os objetivos dessa
dissertação foram validar o uso de marcadores de DNA na identificação da
constituição genética do loco S de genótipos de macieira e na definição de genótipos
polinizadores a serem adotados em pomares comerciais, servindo como ferramenta
auxiliar ao melhoramento genético de macieira. Realizou-se: o estudo da
segregação dos alelos S em populações segregantes de macieira mediante
genotipagem via marcadores de DNA (Capítulo 2); a genotipagem dos alelos S de
28 genótipos elite de macieira via marcadores de DNA e análise de dissimilaridade
genética com base na caracterização quanto aos descritores mínimos requisitados
para a proteção de novas cultivares (Capítulo 3); e a determinação dos genótipos
polinizadores para três cultivares de macieira baseando-se na genotipagem dos
alelos S associada à realização de cruzamentos teste a campo (Capítulo 4). No
estudo da segregação dos alelos S em populações segregantes, a progênie do
cruzamento entre Fred Hough (S5S19) vs. Monalisa (S2S10) apresentou a proporção
de segregação esperada para compatibilidade entre genótipos: 1:1:1:1. Na segunda
população avaliada, em ambos os genitores (M-11/01 e M-13/91) foi identificado o
mesmo par de alelos S: S3S5, sendo que a progênie apresentou esse mesmo
genótipo. Mediante a análise molecular, em 26 dos 28 genótipos avaliados foram
identificados ambos os alelos do loco S, sendo que nos dois restantes apenas um
alelo foi identificado em cada genótipo. A dissimilaridade média dos 28 genótipos
identificada pela caracterização morfoagronômica foi de 35 %. Considerando a
compatibilidade genética total entre os genótipos e as cinco maiores dissimilaridades
obtidas, foram sugeridos 15 cruzamentos para ampliação da base genética do
Programa de Melhoramento Genético da Epagri. Quanto a seleção de polinizadoras,
os testes de polinização a campo não demonstraram diferença significativa entre as
cultivares e suas respectivas polinizadoras para as características avaliadas, porém
quando os alelos S foram identificados constatou-se a presença de casos de
semicompatibilidade entre alguns dos genótipos avaliados. Sugere-se que a não
identificação dos genótipos semicompatíveis ocorre devido a alta concentração de
grãos de pólen aplicada sobre o pistilo das flores via polinização artificial das
cultivares, que pode mascarar a semicompatibilidade existente. Considerando os
resultados obtidos nesse estudo, a utilização de marcadores de DNA para
identificação do genótipo do loco S em macieira pode ser empregada como
ferramenta auxiliar ao programa de melhoramento genético de macieira da Epagri,
tanto para a definição de combinações entre genitores para a formação de
populações segregantes que serão alvo de seleção quanto para a escolha de
polinizadoras geneticamente compatíveis com as cultivares produtoras de frutos a
serem adotados em pomares comerciais, minimizando as perdas de produção em
pomares comerciais devido a semicompatibilidade genética ou incompatibilidade
entre os genótipos de macieira (cultivar copa x polinizadora)
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