Diverged subpopulations in tropical Urochloa (Brachiaria) forage species indicate a role for facultative apomixis and varying ploidy in their population structure and evolution

Abstract Background Urochloa (syn. Brachiaria) is a genus of tropical grasses sown as forage feedstock, particularly in marginal soils. Here we aimed to clarify the genetic diversity and population structure in Urochloa species to understand better how population evolution relates to ploidy level and occurrence of apomictic reproduction. Methods We explored the genetic diversity of 111 accessions from the five Urochloa species used to develop commercial cultivars. These accessions were conserved from wild materials collected at their centre of origin in Africa, and they tentatively represent the complete Urochloa gene pool used in breeding programmes. We used RNA-sequencing to generate 1.1 million single nucleotide polymorphism loci. We employed genetic admixture, principal component and phylogenetic analyses to define subpopulations. Results We observed three highly differentiated subpopulations in U. brizantha, which were unrelated to ploidy: one intermixed with U. decumbens, and two diverged from the former and the other species in the complex. We also observed two subpopulations in U. humidicola, unrelated to ploidy; one subpopulation had fewer accessions but included the only characterized sexual accession in the species. Our results also supported a division of U. decumbens between diploids and polyploids, and no subpopulations within U. ruziziensis and U. maxima. Conclusions Polyploid U. decumbens are more closely related to polyploid U. brizantha than to diploid U. decumbens, which supports the divergence of both polyploid groups from a common tetraploid ancestor and provides evidence for the hybridization barrier of ploidy. The three differentiated subpopulations of apomictic polyploid U. brizantha accessions constitute diverged ecotypes, which can probably be utilized in hybrid breeding. Subpopulations were not observed in non-apomictic U. ruziziensis. Sexual Urochloa polyploids were not found (U. brizantha, U. decumbens) or were limited to small subpopulations (U. humidicola). The subpopulation structure observed in the Urochloa sexual–apomictic multiploidy complexes supports geographical parthenogenesis, where the polyploid genotypes exploit the evolutionary advantage of apomixis, i.e. uniparental reproduction and clonality, to occupy extensive geographical areas

Potencial de rendimiento y calidad de 13 variedades e híbridos comerciales de cítricos en condiciones del piedemonte llanero de Colombia

Con el propósito de seleccionar cultivares de cítricos con potencial productivo y con calidad de fruta adecuada para el consumo, se evaluó el comportamiento de 13 variedades e híbridos de cítricos en condiciones del piedemonte llanero en el departamento del Meta (Colombia). Se midieron las variables de crecimiento (altura de planta, diámetro de copa), potencial productivo (rendimiento por planta y peso de fruto) y calidad del fruto (sólidos solubles totales, acidez total titulable y contenido de jugo). Los cultivares que mostraron mejor potencial productivo y de calidad del fruto fueron: mandarina ‘Dancy’, naranja ‘Crescent Sweet’, toronja ‘Star Ruby’, tangor ‘Ellendale’ y el tangelo ‘Orlando’, estos pueden ser clasificados como materiales promisorios  para la región. Con un comportamiento intermedio en la variable de producción acumulada estuvieron las selecciones de naranja ‘Valencia Rhode Red’, ‘Delta’ y ‘Midknight’, mientras que la naranja ‘Cara-Cara Navel’, la toronja ‘Río Red’ y el tangelo ‘Pear ’ se pueden descartar como potenciales, pues no se adaptaron a las condiciones ambientales del lugar de evaluación, presentando una baja producción y pobre calidad del fruto.El tangelo ‘Pear ’ se confirmó como susceptible a Phytophthora en la evaluación realizada

Genotype-by-Environment Interaction in Interspecific \u3cem\u3eUrochloa\u3c/em\u3e Hybrids Using Factor Analytic Models

Environmental factors can influence plant phenotypes shaping the expression of pastures. The ability to test genotypes in multiple environments is critical in a breeding program because important traits are heavily influenced by the environment. Nutritional quality is critical in forage breeding because it affects the rate of live weight gain in livestock as well as the quality of end products such as milk and meat. However, there is not much information on the environmental effect on agronomic and nutritional quality traits in tropical forages. For this reason, the objective of the present study was to investigate the genotype-by-environment interaction in a breeding population of interspecific Urochloa hybrids evaluated for agronomic and nutritional quality traits across four locations in Colombia, using factor analytic mixed models. Phenotypic correlations among traits ranged from 0.26 (plant area vs dry weight) to 0.93 (fresh weight vs dry weight), indicating a strong interaction in some traits. Genetic correlations among environments showed different ranges depending on the variable evaluated. For example, plant height genetic correlations among environments ranged from 0.16 to 0.9, indicating high genotype-byenvironment interaction. The factor analytic analysis revealed that two factors explained more than 60% of the genetic variance in all traits evaluated and that 80% of the environments were clustered in the first factor. Factor analytic biplot indicates that Llanos location differed strongly from other locations evaluated. Based on the results obtained, the factor analytic analysis is a useful tool to stratify environments and identify Urochloa cultivars adapted to different ecological niches

The type VI secretion system of Xanthomonas phaseoli pv. manihotis is involved in virulence and in vitro motility.

BACKGROUND: The type VI protein secretion system (T6SS) is important in diverse cellular processes in Gram-negative bacteria, including interactions with other bacteria and with eukaryotic hosts. In this study we analyze the evolution of the T6SS in the genus Xanthomonas and evaluate its importance of the T6SS for virulence and in vitro motility in Xanthomonas phaseoli pv. manihotis (Xpm), the causal agent of bacterial blight in cassava (Manihot esculenta). We delineate the organization of the T6SS gene clusters in Xanthomonas and then characterize proteins of this secretion system in Xpm strain CIO151. RESULTS: We describe the presence of three different clusters in the genus Xanthomonas that vary in their organization and degree of synteny between species. Using a gene knockout strategy, we also found that vgrG and hcp are required for maximal aggressiveness of Xpm on cassava plants while clpV is important for both motility and maximal aggressiveness. CONCLUSION: We characterized the T6SS in 15 different strains in Xanthomonas and our phylogenetic analyses suggest that the T6SS might have been acquired by a very ancient event of horizontal gene transfer and maintained through evolution, hinting at their importance for the adaptation of Xanthomonas to their hosts. Finally, we demonstrated that the T6SS of Xpm is functional, and significantly contributes to virulence and motility. This is the first experimental study that demonstrates the role of the T6SS in the Xpm-cassava interaction and the T6SS organization in the genus Xanthomonas

Complex polyploid and hybrid species in an apomictic and sexual tropical forage grass group: genomic composition and evolution in Urochloa (Brachiaria) species

Background and Aims Diploid and polyploid Urochloa (including Brachiaria, Panicum and Megathyrsus species) C-4 tropical forage grasses originating from Africa are important for food security and the environment, often being planted in marginal lands worldwide. We aimed to characterize the nature of their genomes, the repetitive DNA and the genome composition of polyploids, leading to a model of the evolutionary pathways within the group including many apomictic species. Methods Some 362 forage grass accessions from international germplasm collections were studied, and ploidy was determined using an optimized flow cytometry method. Whole-genome survey sequencing and molecular cytogenetic analysis were used to identify chromosomes and genomes in Urochloa accessions belonging to the 'brizantha' and 'humidicola' agamic complexes and U. maxima. Key Results Genome structures are complex and variable, with multiple ploidies and genome compositions within the species, and no clear geographical patterns. Sequence analysis of nine diploid and polyploid accessions enabled identification of abundant genome-specific repetitive DNA motifs. In situ hybridization with a combination of repetitive DNA and genomic DNA probes identified evolutionary divergence and allowed us to discriminate the different genomes present in polyploids. Conclusions We suggest a new coherent nomenclature for the genomes present. We develop a model of evolution at the whole-genome level in diploid and polyploid accessions showing processes of grass evolution. We support the retention of narrow species concepts for Urochloa brizantha, U. decumbens and U. ruziziensis, and do not consider diploids and polyploids of single species as cytotypes. The results and model will be valuable in making rational choices of parents for new hybrids, assist in use of the germplasm for breeding and selection of Urochloa with improved sustainability and agronomic potential, and assist in measuring and conserving biodiversity in grasslands

ADENOCARCINOMA PAPILAR DEL CUELLO UTERINO: COMUNICACIÓN DE UN CASO Y REVISIÓN DE LA LITERATURA

Se presenta el caso clínico de una paciente de 42 años con diagnóstico de adenocarcinoma seroso papilar del cuello uterino etapa Ib1 tratada mediante histerectomía radical más linfadenectomía pélvica bilateral. El estudio anatomopatológico demostró bordes quirúrgicos libres y ausencia de enfermedad metastásica ganglionar por lo que se consideró a la paciente tratada. Este es el primer caso de adenocarcinoma seroso papilar del cuello uterino reportado en el país. Hay que descartar el compromiso cervical secundario por tumores serosos de endometrio, ovario o trompa antes de plantear el origen primario de cuello uterino. No se conoce el real comportamiento, pronóstico y óptimo tratamiento en este tipo de tumores. La determinación de los niveles de CA-125 basal y seriados durante el seguimiento pudiese ser de utilidad en la evaluación del tratamiento realizado y en la sospecha de enfermedad persistente o reciPad

VOLUMEN 18, NÚMERO 32 (1989)

MODELO PRELIMINAR DE SEDIMENTACIÓN ACTUAL EN EL GRABEN COLOMBO - ECUATORIANO. Padilla, L. E.; León, L. A.ASPECTOS GEOLÓGICOS Y GEOMORFOLÓGICOS DE COMO EL RÍO CAUCA CORRÍA HACIA EL SUR. Padilla, L. E.; León, L. A.ESTUDIO TEXTURAL Y COMPOSICIONAL DE SEDIMENTOS ACTIVOS DEL RÍO MAGDALENA, ENTRE NEIVA Y BOCAS DE CENIZA. Castiblanco, C. R.; Lombana, P. E.APPLICATION OF SCANNING ELECTRON MICROSCOPE AND X-RAY MICROANALYSIS TECHNIQUES IN THE EVALUATION OF RESERVOIR QUALITY AND PETROLEUM PRODUCTION PROBLEMS. Reyes, R.; Pinzón, P.TÉCNICAS DE EVALUACIÓN DE PROYECTOS CARBONÍFEROS. Ortega, C

VOLUMEN 18, NÚMERO 32 (1989)

MODELO PRELIMINAR DE SEDIMENTACIÓN ACTUAL EN EL GRABEN COLOMBO - ECUATORIANO. Padilla, L. E.; León, L. A.ASPECTOS GEOLÓGICOS Y GEOMORFOLÓGICOS DE COMO EL RÍO CAUCA CORRÍA HACIA EL SUR. Padilla, L. E.; León, L. A.ESTUDIO TEXTURAL Y COMPOSICIONAL DE SEDIMENTOS ACTIVOS DEL RÍO MAGDALENA, ENTRE NEIVA Y BOCAS DE CENIZA. Castiblanco, C. R.; Lombana, P. E.APPLICATION OF SCANNING ELECTRON MICROSCOPE AND X-RAY MICROANALYSIS TECHNIQUES IN THE EVALUATION OF RESERVOIR QUALITY AND PETROLEUM PRODUCTION PROBLEMS. Reyes, R.; Pinzón, P.TÉCNICAS DE EVALUACIÓN DE PROYECTOS CARBONÍFEROS. Ortega, C

Alternativas práticas ao modelo de saúde ocidental, utilizadas pelos cuidadores de pacientes com neoplasia hematológicas

Introducción: Las neoplasias hematológicas tienen la carga cultural de la palabra cáncer lo cual lleva a los cuidadores a buscar diversas alternativas. Objetivo: Describir las prácticas consideradas alternativas al modelo de salud occidental utilizadas para el cuidado de la salud, desde la experiencia de los cuidadores de pacientes adultos con neoplasias hematológicas en un Servicio de Hematología. Metodología: Estudio cualitativo descriptivo. Participaron 17 cuidadores de pacientes adultos con neoplasias hematológicas, seleccionados por conveniencia del registro del servicio de Hematología. Como técnica de recolección se realizaron dos grupos de discusión. Las sesiones fueron grabadas y transcritas en su totalidad. El análisis se hizo de acuerdo con la propuesta de Janice M. Morse y se efectuó triangulación por parte de investigadores. Resultados: Emergieron tres tipos de prácticas. 1. Prácticas espirituales: la voluntad de Dios como influyente en la recuperación.; 2. Las prácticas afectivas: los lazos familiares hacen más llevadera la enfermedad y el tratamiento, y 3. Prácticas Corporales: productos de origen, vegetal, animal, semisintético y farmacológicos no convencionales. Conclusión: Los cuidadores de la población con Cáncer utilizan prácticas alternativas al tratamiento convencional, por tanto, el equipo de salud no puede ignorarlas y necesita fortalecer la orientación al paciente y sus cuidadores.Introduction: Hematological neoplasms have the cultural burden of the word cancer which leads caregivers to look for different alternatives. Objective: To analyse the anthropological link between care and tenderness to potentiate care as an essential “way to be” of the human being, who ontological way was born of care and needs care. Methodology: Descriptive qualitative study. The participants were 17 caregivers, who were selected by convenience. Two discussion groups’ sessions were performed. The sessions were recorded and transcribed in full. The analysis followed the Janice M. Morse framework. Results: The findings that emerged permitted an approach toward understanding the practices used to care for patients affected by malignant hematological disease. The practices were organized in three types: 1. Spiritual practices: God´s Will as determinant in the recovery process; 2. Emotional Practices: the familiar ties make more bearable the illness and the treatment, and, 3. Corporal practices: origin products, vegetal, animal, semi-synthetic and no conventional pharmacological products. Conclusion: The utilization of alternative practices is very common by caregivers. Healthcare practitioners cannot ignore this reality and need tools to adequately guide and inform patients and caregivers.Introdução: As neoplasias hematológicas têm carga cultural da palavra câncer, levando aos cuidadores das pessoas que o sofrem a procurar diversas alternativas. Objetivo: Descrever as práticas consideradas alternativas ao modelo de saúde Ocidental usado para cuidados de saúde, a partir da experiência de cuidadores de pacientes adultos com doenças hematológicas malignas no servicio de Hematologia Hospital San José de Bogotá. Metodologia: Estudo qualitativo descritiva. Participaram 17 cuidadores de pacientes adultos com neoplasias hematológicas, seleccionados por conveniência dos registos do servicio Hematologia. Como uma técnica de coleta de informações dois grupos de discussão foram realizadas. As sessões foram gravadas e transcritas em sua totalidade. A análise foi feita de acordo com a proposta Janice M Morse e se efectou uma triangulação foi realizado por pesquisadores. Resultados: Surgiram três tipos de práticas utilizadas para cuidar de pessoas afectadas pela doença hematológica maligna; 1. As práticas espirituais: a vontade de Deus tão influente na recuperação;. 2. práticas Affective: laços familiares tornar mais suportável a doença e o tratamento, e 3. práticas corporais: produtos de origem vegetal, animal, semi-sintético e farmacológico não convencional. Conclusão: Os cuidadores de pessoas com câncer muitas vezes usam alternativa às práticas convencionais de tratamento, assim, a equipe de saúde não pode ignorar esta realidade e precisa de reforçar a orientação aos pacientes e seus cuidadores

Managing neotropical oil palm expansion to retain phylogenetic diversity

Summary: The expansion of tropical agriculture is a major driver of the extinction crisis. A key question is whether biodiversity losses can be minimized by restricting future expansion to low-productivity farmland and retaining forest fragments, especially in rapidly changing Neotropical landscapes. We investigated these methods in the context of avian phylogenetic diversity, which summarizes the evolutionary history preserved within communities. Evidence suggests that phylogenetic diversity plays an important role in maintaining key ecosystem functions. We collected data on avian communities in the Colombian Llanos, a region highlighted as being optimal for the expansion of oil palm, at the expense of existing habitats including forest remnants and improved cattle pastures. PD, a measure of phylogenetic richness, and MPD, a measure of the phylogenetic distance between individuals in a community in deep evolutionary time, were significantly higher in forest than in oil palm or pasture, but did not differ significantly between oil palm and pasture. MNTD, a measure of distance between individuals in a community at the intra-familial and intra-generic level, was significantly higher in oil palm and pasture than in forest. However, median evolutionary distinctiveness (ED) was highest in pasture, partly due to the abundance of distinct waterbirds, but did not differ between oil palm and forest. PD in oil palm and pasture increased with the extent of remnant forest cover. Synthesis and applications. The PD (a measure of phylogenetic richness) and MPD (a measure of the phylogenetic distance) of bird communities in this region can best be conserved by ensuring that new oil palm plantations replace pasturelands rather than forest. A secondary benefit of preserving forest would be the enhancement of PD in the surrounding agricultural landscape. This strategy will need to be coupled with measures to either reduce pasture demand or to intensify existing cattle production to ensure that forest is not replaced by pasture elsewhere