3,909 research outputs found
Loss of redundant gene expression after polyploidization in plants
Based on chromosomal location data of genes encoding 28 biochemical systems in allohexaploid wheat,Triticum aestivum L. (genomes AABBDD), it is concluded that the proportions of systems controlled by triplicate, duplicate, and single loci are 57%, 25%, and 18% respectively
Resistance to eyespot (Pseudocercosporella herpotricoides) and distribution of biochemical markers in hexaploid lines derived from double cross (Triticum turgidum x Aegilops ventricosa) x T. aestivum
There are not good intraspecific sources of resistance to the eyespot disea se of wheat, aaused by Cercosporella herpotrichoides Fvon . The -Ănterspecifia transfer of genes for resistanoe from Aegitops ventricosa into hexaploid wheat has been only partially achieved, because the degree of resistanoe attained is not as high as that of the donor. We report here on the transfer of resistanoe in a double oross (Triticum turgidum var. rubroatrwv H-1-1 x Ae.ventricosa AP-D x T.aestivum cv. Almatense H-10-15. The high level of resistanoe in a high proportion of the lines strongly suggests a simple genetic control for this oharacter (possibly by one major gene). The gene(s) responsible for resistanoe in the selected lines must be associa ted with the D genome of Aegilops ventricosa on the basis of a detailed study of the distribution of biochemioal markers in the H-93 lines. These results do not exelude that genes with similar effeets might be looated in the M° genome
Eyespot resistance gene Pch-1 from Aegilops ventricosa is associated with a different chromosome in wheat line H-93-70 than the resistance factor in "Roazon" wheat
The hexaploid wheat line H-93-70 carries a gene (Pch-1) that has been transferred from the wild grass Aegilops ventricosa and confers a high degree of resistance to eyespot diesease, caused by the fungus Pseudocercosporella herpotrichoides. Crosses of the resistant line H-93-70 with the susceptible wheat Pané 247 and with a 7D/7Ag wheat/Agropyron substitution line were carried out and F2 kernels were obtained. The kernels were cut transversally and the halves carrying the embryos were used for the resistance test, while the distal halves were used for genetic typing. Biochemical markers were used to discriminate whether the transferred Pch-1 gene was located in chromosome 7D, as is the case for a resistance factor present in Roazon wheat. In the crosses involving Pané 247, resistance was not associated with the 7D locus Pln, which determines sterol ester pattern (dominant allele in H-93-70). In the crosses with the 7D/7Ag substitution line, resistance was neither associated with protein NGE-11 (7D marker), nor alternatively inherited with respect to protein C-7 (7Ag marker). It is concluded that gene Pch-1 represents a different locus and is not an allele of the resistance factor in Roazon whea
Treinamento presencial e à distância em mapeamento digital de solos para latinoamericanos.
A produção de informação de solos Ă© demorada e custosa, sendo essa informação essencial para a agricultura, gerenciamento dos recursos naturais, simulações dos efeitos das mudanças climáticas, entre outros. O mapeamento digital de solos (MDS) tem avançado como metodologia complementar ao levantamento clássico de solos buscando soluções rápidas e eficazes para o mapeamento de solos, utilizando dados auxiliares (covariáveis) e mĂ©todos estatĂsticos e matemáticos. Nesse contexto, a Embrapa Solos realizou, atravĂ©s de um acordo firmado com a Organização das Nações Unidas para a Alimentação e a Agricultura (FAO), cursos de capacitação em MDS para tĂ©cnicos de 18 paĂses da AmĂ©rica Latina e Caribe (LAC). Foram oferecidos dois cursos presenciais nas instalações da Embrapa Solos, no Rio de Janeiro, RJ, Brasil, e um curso Ă distância, onde foram empregados softwares livres para preparação e análise de dados (SAGA, R e RStudio), criação de vĂdeo (CamStudio e iSpring) e ensino Ă distância (Moodle). Os cursos tiveram conteĂşdo teĂłrico-prático, tendo sido realizado como estudo de caso no primeiro curso presencial o mapeamento digital de carbono do solo (cujos resultados sĂŁo apresentados em outro trabalho nestes anais). Este trabalho apresenta a experiĂŞncia desenvolvida pela Embrapa Solos e os principais resultados do esforço para capacitar, presencialmente e Ă distância, tĂ©cnicos de diferentes paĂses da LAC em MDS
Treinamento em mapeamento digital de solos: carbono no Rio de Janeiro, Brasil.
No perĂodo de 24 a 28 de setembro de 2012 foi realizado na Embrapa Solos, Rio de Janeiro, RJ, o Curso de CapacitaciĂłn en CartografĂa Digital de Suelos, que contou com a presença de 17 pedĂłlogos de 17 paĂses da AmĂ©rica Latina e Caribe. O objetivo do curso foi capacitar os pedĂłlogos em mapeamento digital de solos utilizando os softwares livres SAGA, R e RStudio. No curso realizou-se, como estudo de caso, o mapeamento do carbono orgânico do solo na camada 0-10 cm no municĂpio de Campos dos Goytacazes, RJ, Brasil. Apresentamos as etapas de treinamento realizadas durante o curso, incluindo a preparação de dados de solos e covariáveis ambientais, análise exploratĂłria de dados, modelagem espacial, produção de mapas e validação dos resultados obtidos. A combinação dos softwares livres SAGA, R e RStudio mostrou-se bastante flexĂvel para a realização do curso e mapeamento digital de carbono orgânico do solo, sendo recomendada para outros cursos e projetos de mapeamento digital de solos. A estrutura do curso mostrou-se adequada tambĂ©m para implementação atravĂ©s de ensino Ă distância (resultados apresentados em outro trabalho nestes anais). Para ĂŞxito de cursos e projetos similares, salientamos a importância da experiĂŞncia prĂ©via dos participantes com conceitos e tĂ©cnicas de pedologia, estatĂstica, geoprocessamento e linguagem de programação, bem como da existĂŞncia de um banco de dados de solos organizado e disponĂvel
Capacitação em mapeamento digital de solos. Parte 1- cursos presenciais e à distância para técnicos da América Latina e Caribe.
A produção de informação de solos Ă© muito demorada e custosa, sendo essa informação essencial na agricultura, gerenciamento dos recursos naturais, simulações dos efeitos das mudanças climáticas, entre outros. É de tal importância este problema de falta de informação de solos, que cientistas de solos do mundo tĂŞm utilizado o mapeamento digital de solos (MDS) como metodologia para encontrar soluções rápidas e eficazes para geração dessa informação, utilizando dados auxiliares (covariáveis) e mĂ©todos estatĂsticos e matemáticos. Nesse contexto, a Embrapa Solos realizou, atravĂ©s de um acordo firmado com a Organização das Nações Unidas para a Alimentação e a Agricultura (FAO), cursos de capacitação em MDS para tĂ©cnicos de 18 paĂses da AmĂ©rica Latina e Caribe. Foram oferecidos dois cursos presenciais nas instalações da Embrapa Solos, no Rio de Janeiro, RJ, e um curso Ă distância, onde foram empregados softwares livres para preparação e análise de dados (SAGA, R e RStudio), criação de vĂdeo (CamStudio e iSpring) e ensino Ă distância (Moodle). Os cursos tiveram conteĂşdo teĂłrico-prático, tendo sido realizado como estudo de caso no primeiro curso presencial o mapeamento digital de carbono orgânico do solo (cujos resultados sĂŁo apresentados em outro trabalho nestes anais). Este trabalho apresenta a experiĂŞncia desenvolvida pela Embrapa Solos e os principais resultados do esforço para capacitar, presencialmente e Ă distância, tĂ©cnicos de diferentes paĂses em MDS
Power Doppler can detect the presence of 7–8 day conceptuses prior to flushing in an equine embryo transfer program
In order to determine whether differences in uterine blood flow between pregnant and non-pregnant mares can be used to predict the presence of the equine embryo prior to flushing in an embryo transfer program, power Doppler ultrasonography was used on a total of 52 mares on days 7 or 8 post-ovulation. Computer analysis of Doppler images was subsequently performed using ImageJ v1.48 software. Vascular perfusion of the endometrium was analyzed using spot meter techniques, measuring mean pixel intensity and area of blood flow. Mares with positive flushings presented a higher uterine blood flow area (one embryo: 54.01 ± 2.27 mm2 or two embryos: 61.01 ± 6.73 mm2) prior to embryo recovery compared to barren mares (21.77 ± 2.22 mm2) (p ≤ 0.05). However, significant differences in vascular perfusion were not detected between single or twin pregnancies. Blood flow area appears to be a good predictor for differentiation between pregnant and non-pregnant mares with an AUC: 0.869; p ≤ 0.001 and an optimal cut-off value of 37.21 mm2. Both the mare's age and day of embryo recovery caused effects on uterine vascular perfusion. According to Youden's J statistics the uterine blood flow area of young pregnant mares was greater than 25.4 mm2 on day 7 (with a sensitivity of 75% and a specificity of 87.5%) and greater than 21.02 mm2 on day 8 post-ovulation (with a sensitivity of 93.8% and a specificity of 100%). The uterine blood flow area in adult pregnant mares was greater than 41.4 mm2 on day 7 (with a sensitivity of 80% and a specificity of 85.5%) and greater than 35.55 mm2 on day 8 after ovulation (with a sensitivity of 97.2% and a specificity of 85.7%). Evaluation on day 8 is therefore considered to be more reliable. Older and middle aged pregnant mares (5–18 years old) had increased uterine vascularization compared to young pregnant mares (2–5 years old) (p ≤ 0.001). Conversely, older barren mares showed higher endometrial vascularity (35.06 ± 2.56 mm2) than young (17.21 ± 1.26 mm2) and middle aged non-pregnant mares (23.84 ± 1.50 mm2) (p ≤ 0.05). We hypothesized that the higher blood flow area seen in older barren mares may be a consequence of a subclinical endometritis due to repeated flushing for embryo recovery. The results of the present study indicate that power Doppler ultrasound combined with computer assisted analysis of images are reliable techniques to detect early pregnancy prior to embryo recovery
Dataset of endometrial blood flow from pregnant and non-pregnant mares on day 7 and 8 post-ovulation
This article provides the dataset for the use of power Doppler ultrasound to assess the equine uterus from the recent research article titled “Power Doppler can detect the presence of 7-8 days conceptuses prior to flushing in an equine embryo transfer program”(1). The vascularization of the endometrium was objectively assessed in mares by quantification of pixels in bitmap format (BMP) using computer assisted analysis of images. Fifty-two mares were examined on days 7 (26 mares) and 8 (26 mares) post-ovulation prior to performing flushing procedures for embryo recovery. Receiver operating characteristic (ROC) curves and Youden's J statistics were used to evaluate the value of the suggested variable in terms of its diagnostic value for identification of early pregnancy and to establish cut-off values allowing differentiation between pregnant and non-pregnant mares on days 7 and 8 post-ovulation
Biochemical and cytological characterization of wheat/Aegilops ventricosa addition and transfer lines carrying chromosome 4MV
The gene encoding a variant of alcohol dehydrogenase, Adh-, has been found to be associated with the chromosome of the Mv genome which is present in type 9 wheat/Aegilops ventricosa addition line, to which the genes for protein CM-4 and for a phosphatase variant, Aph-v, had been previously assigned. Transfer line H-93-33, which has 42 chromosomes and has been derived from the cross (Triticum turgidum x Ae. ventricosa) x T. aestivum, carries genes encoding all three biochemical markers. Linkage between these genes has been demonstrated by analysis of individual kernels of the F2 (H-93-33 x T. aestivum cv. Almatense H-10-15). A study of the hybrids of line H-93-33 with T. aestivum H-10-15 and with the 4DS ditelosomic line has confirmed that, as suspected, the linkage group corresponds to chromosome 4Mv from Ae. ventricosa. Additionally, it has been found that the previously reported resistance of line H-93-33 to powdery mildew (Erysiphe graminis) is also linked to the biochemical markers; this indicates that either the gene responsible for it is different from that in lines H-93-8 and H-93-35, or that a translocation between two different Mv chromosomes has occurred in line H-93-33
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