105 research outputs found

    Host responses of different Triticeae to species of the cereal cyst nematode complex in relation to breeding resistant durum wheat

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    Vingt-huit lignées ou cultivars de #Triticum diploïdes (génomes A, D, S(I), U), tétraploïdes (génomes AB, D(V)M(V), UM, US(V)) et hexaploïdes (génome ABD) ont été étudiés pour leur capacité à permettre le développement de neuf populations d'#Heterodera avenae originaires de six pays (Algérie, France, Espagne, Australie, Israël et Inde), deux populations d'#Heterodera filipjevi provenant de Russie et de Bulgarie et une population d'#Heterodera latipons provenant d'Israël. Les tests ont été conduits dans des conditions artificielles selon une technique miniaturisée. Les résultats ont montré une résistance élevée à l'encontre des populations d'#H. avenae sensu stricto au sein des trois niveaux de ploïde et dans les différents génomes S(1) (#T. longissimum), D(V)M(V) (#T. ventricosum), UM (#T. ovatum), US(V) (#T. variabile) et ABD (#T. aestivum AUS 4930). Des sources de résistance complÚte ou partielle ont été trouvées dans le génome D (#T. tauschii CPI 110813 ou AUS 18913), mais leur expression dans les blés hexaploïdes synthétiques est incomplÚte. Il a été confirmé que le gÚne #Cre1 du blé cv. Loros est inefficace contre les populations d'#H. avenae d'Australie, d'Inde, et d'Israël, ainsi que contre les populations d'#H. filipjevi. La différenciation inter- et intraspécifique dans ce complexe de nématodes à kystes des céréales pour leur (a)virulence vis-à-vis de #Triticeae$ et leur capacité reproductive intrinsÚque sont discutées, ainsi que l'utilisation de résistances complÚte et partielle dans les programmes de sélection. (Résumé d'auteur

    Pump-probe measurement of atomic parity violation in caesium with a precision of 2.6%

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    We present the atomic parity violation measurements made in Cs vapour using a pump-probe scheme. After pulsed excitation of the 6S-7S forbidden transition in the presence of a longitudinal electric field, a laser beam resonant with one of the 7S-6P transitions stimulates the 7S atom emission for a duration of 20 ns. The polarisation of the amplified probe beam is analysed. A seven-fold signature allows discrimination of the parity violating linear dichroism, and real-time calibration by a similar, known, parity conserving linear dichroism. The zero-field linear dichroism signal due to the magnetic dipole transition moment is observed for the first time, and used for in-situ determination of the electric field. The result, ImE1^{pv}= (-808+/- 21) 10^{-14} ea\_{0}, is in perfect agreement with the corresponding, more precise measurement obtained by the Boulder group. A transverse field configuration with large probe amplification could bring atomic parity violation measurements to the 0.1% accuracy level.Comment: "conference PAVI 06, Milos, Greece, May 2006

    Transfer of recessive skr crossability trait into well-adapted French wheat cultivar Barok through marker-assisted backcrossing method

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    In order to increase genetic diversity in cereals, interspecific or even intergeneric crosses are worthwhile, especially wheat by rye crosses for triticale production. However, these crosses often fail due to inhibiting genes. To overcome this obstacle, crossability trait, present in a few wheat cultivars, can be transferred into other wheat lines of agronomical interest. Nevertheless, this transfer remains tedious through conventional backcrossing methods because it is a recessive trait, which requires selfing generations and complex evaluation by many crosses. Here, we present a marker-assisted backcrossing method to transfer this trait more quickly and easily. We chose to introduce the recessive crossability skr, located on chromosome 5BS and originating from Asian wheat, into Barok, a non-crossable French wheat cultivar, with good agronomic characteristics. Six molecular markers, close to the Skr locus, were used to check the transfer of the gene at each of the three backcrosses, without selfing generation nor crosses with rye. Finally, we crossed the predicted crossable lines with rye to validate their crossability. We obtained sixteen lines, morphologically similar to Barok, exhibiting high crossability rate (30%). The markers were thus efficient to transfer the skr crossability but they remain too far from the Skr locus to be considered as diagnostic markers. Indeed, genotyping and phenotyping on other wheat cultivars showed some discrepancies. Nevertheless, this opens the way to enhance genetic diversity more easily and to improve traits of agronomic interest in triticale or wheat as well as to study further barriers to intergeneric crosses

    A new Manifestation of Atomic Parity Violation in Cesium: a Chiral Optical Gain induced by linearly polarized 6S-7S Excitation

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    We have detected, by using stimulated emission, an Atomic Parity Violation (APV) in the form of a chiral optical gain of a cesium vapor on the 7S - 6P3/2_{3/2} transition,consecutive to linearly polarized 6S-7S excitation. We demonstrate the validity of this detection method of APV, by presenting a 9% accurate measurement of expected sign and magnitude. We underline several advantages of this entirely new approach in which the cylindrical symmetry of the set-up can be fully exploited. Future measurements at the percent level will provide an important cross-check of an existing more precise result obtained by a different method.Comment: 4 pages, 2 figure

    Transfer of a major dominant gene for resistance to eyespot disease from a wild grass to hexaploid wheat

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    Eyespot disease, caused by the fungus Pseudocercosporella herpotrichoides, is responsible for considerable lodging and reductions of yield in extensive areas of wheat cultivation in North and South America, Europe, New Zealand, Australia and Africa1. The level of resistance of wheat cultivars is too low, even among the less susceptible ones (that is, Cappelle Desprez and Cerco) and no genes for resistance have to date been characterized in any species. Sprague2 found a high level of resistance to this disease in the wild grass Aegilops ventricosa and several workers have attempted its transfer to cultivated wheat with only partial success3−5. We report here a major dominant gene for resistance, which has been transferred from tetraploid Ae. ventricosa (genomes DvDvMvMv) to hexaploid wheat, Triticum aestivum (AABBDD), using tetraploid wheat, Triticum turgidum (AABB), as a 'bridge' species

    Asynchronous Testing of Synchronous Components in GALS Systems

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    International audienceGALS (Globally Asynchronous Locally Synchronous) systems, such as the Internet of Things or autonomous cars, integrate reactive synchronous components that interact asynchronously. The complexity induced by combining synchronous and asynchronous aspects makes GALS systems difficult to develop and debug. Ensuring their functional correctness and reliability requires rigorous design methodologies, based on formal methods and assisted by validation tools. In this paper we propose a testing methodology for GALS systems integrating: (1) synchronous and asynchronous concurrent models; (2) functional unit testing and behavioral conformance testing; and (3) various formal methods and their tool equipments. We leverage the conformance test generation for asynchronous systems to automatically derive realistic scenarios (input constraints and oracle), which are necessary ingredients for the unit testing of individual synchronous components, and are difficult and error-prone to design manually. We illustrate our approach on a simple, but relevant example inspired by autonomous cars

    Prediction of All-Cause Mortality Following Percutaneous Coronary Intervention in Bifurcation Lesions Using Machine Learning Algorithms

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    Stratifying prognosis following coronary bifurcation percutaneous coronary intervention (PCI) is an unmet clinical need that may be fulfilled through the adoption of machine learning (ML) algorithms to refine outcome predictions. We sought to develop an ML-based risk stratification model built on clinical, anatomical, and procedural features to predict all-cause mortality following contemporary bifurcation PCI. Multiple ML models to predict all-cause mortality were tested on a cohort of 2393 patients (training, n = 1795; internal validation, n = 598) undergoing bifurcation PCI with contemporary stents from the real-world RAIN registry. Twenty-five commonly available patient-/lesion-related features were selected to train ML models. The best model was validated in an external cohort of 1701 patients undergoing bifurcation PCI from the DUTCH PEERS and BIO-RESORT trial cohorts. At ROC curves, the AUC for the prediction of 2-year mortality was 0.79 (0.74–0.83) in the overall population, 0.74 (0.62–0.85) at internal validation and 0.71 (0.62–0.79) at external validation. Performance at risk ranking analysis, k-center cross-validation, and continual learning confirmed the generalizability of the models, also available as an online interface. The RAIN-ML prediction model represents the first tool combining clinical, anatomical, and procedural features to predict all-cause mortality among patients undergoing contemporary bifurcation PCI with reliable performance

    Partial Resistance to Heterodera avenae in Wheat Lines with the 6M v Chromosome from Aegilops ventricosa

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    Lines of wheat with the 6Mv chromosome from Aegilops ventricosa display partial resistance to both pathotypes Hal2 and Ha41 of Heterodera avenae. With either pathotype, the effect of this alien chromosome on cyst production, size, and fecundity was expressed in resistance tests. Partial resistance of five 6Mv(6D) substitution lines varied according to the intrinsic cyst-forming capacity of the nematode pathotypes and the recipient germplasms. Such partial resistance can be utilized in wheat breeding lines for integrated management of the cereal cyst nematode
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