Development of functional markers specific for seven Pm3 resistance alleles and their validation in the bread wheat gene pool

In the ideal case, molecular markers used for marker-assisted selection are allele-specific even if the alleles differ only by a few nucleotide polymorphisms within the coding sequence of target genes. Such ‘perfect' markers are completely correlated with the trait of interest. In hexaploid wheat (Triticum aestivum L.) the Pm3 locus encodes seven alleles (Pm3a-Pm3g) conferring resistance to different races of Blumeria graminis f.sp. tritici, the agent of powdery mildew, a major disease of bread wheat. All Pm3 alleles are known at the molecular level. Here, we generated specific markers for the Pm3 alleles based on nucleotide polymorphisms of coding and adjacent non-coding regions. The specificity of these markers was validated in a collection of 93 modern or historically important cultivars and breeding lines of wheat and spelt (Triticum spelta L.). These markers confirmed the presence of the predicted Pm3 alleles in 31 varieties and lines known to carry Pm3 resistance alleles. In a few varieties, Pm3 alleles different from alleles previously described based on pathogenicity tests or tightly linked markers were observed. In all these cases, the identity of the marker-detected Pm3 alleles was confirmed by DNA sequence analysis. Pm3 markers confirmed the absence of known Pm3 resistance alleles in 54 European wheat and spelt varieties in which Pm3 alleles had not been previously identified. These results indicate that the developed markers are highly diagnostic for specific Pm3 resistance alleles in a wide range of varieties and breeding lines, and will be useful (1) for identifying Pm3 alleles in the wheat gene pool, (2) for efficient marker-assisted selection of these genes, and (3) for combining multiple Pm3 alleles within a single cultivar through transgenic approache

A generalized quantum nonlinear oscillator

We examine various generalizations, e.g. exactly solvable, quasi-exactly solvable and non-Hermitian variants, of a quantum nonlinear oscillator. For all these cases, the same mass function has been used and it has also been shown that the new exactly solvable potentials possess shape invariance symmetry. The solutions are obtained in terms of classical orthogonal polynomials

A MEMS-based solid propellant microthruster array for space and military applications

Since combustion is an easy way to achieve large quantities of energy from a small volume, we developed a MEMS based solid propellant microthruster array for small spacecraft and micro-air-vehicle applications. A thruster is composed of a fuel chamber layer, a top-side igniter with a micromachined nozzle in the same silicon layer. Layers are assembled by adhesive bonding to give final MEMS array. The thrust force is generated by the combustion of propellant stored in a few millimeter cube chamber. The micro-igniter is a polysilicon resistor deposited on a low stress SiO2/SiNx thin membrane to ensure a good heat transfer to the propellant and thus a low electric power consumption. A large range of thrust force is obtained simply by varying chamber and nozzle geometry parameters in one step of Deep Reactive Ion Etching (DRIE). Experimental tests of ignition and combustion employing home made (DB+x% BP) propellant composed of a Double-Base and Black-Powder. A temperature of 250 therefore degrees C, enough to propellant initiation, is reached for 40 mW of electric power. A combustion rate of about 3.4 mm/s is measured for DB+20% BP propellant and thrust ranges between 0.1 and 3,5 mN are obtained for BP ratio between 10% and 30% using a microthruster of 100 mu m of throat wide

Forced oscillations dynamic tribometer with real-time insights of lubricated interfaces

This paper presents an innovative forced oscillations dynamic tribometer, the CHRONOS tribometer, with a lubricated ball-on-flat contact configuration fitted out with an in situ optical visualization system and a triggered high-speed camera. The CHRONOS tribometer generates controlled oscillating kinematics by means of a shaker with a range of strokes from 5 μm to 2.5 mm and an oscillation frequency which can be adjusted from 5 Hz to 250 Hz. Displacement and velocity are measured using a vibrometer. The ball-on-flat mean contact pressure is set between 200 MPa and 600 MPa. During motion, the instantaneous normal and friction forces and the interfacial film thickness distribution (in the nanometer scale) are simultaneously measured. In addition to this instantaneous approach, a more macroscopic approach is developed in terms of moving averages of friction and velocity. Another parameter, the friction-velocity tilt angle, is also introduced. This last parameter may give information on the friction-velocity dependence. Eventually, the experiments performed on the CHRONOS device lead to the representation of synchronized temporal signals of displacement/velocity, friction, and lubricant central film thickness. This superimposition of key parameters reveals time effects introduced by the periodical fluid squeeze and flow in the contact

Molecular analysis of fungal disease resistance in wheat

La influencia de las Tecnologías de la Información y Comunicación (TIC) en el sector turístico y en especial en la comunicación de los productos y en la gestión de las relaciones con los públicos es ampliamente conocida. Las aplicaciones Web 2.0 basadas en comentarios y valoraciones de usuarios a escala mundial, en concreto TripAdvisor, influencian las prácticas en relaciones públicas y comunicación turísticas obligando a una cuidada gestión de la reputación online. Si por un lado las nuevas herramientas 2.0 están à disposición de las organizaciones para comunicar con sus públicos, por otro lado son también fuente de comentários y valoraciones directas que pueden reforzar positivamente la imagen de una organización o contribuir con opiniones negativas que desafian nuevas práticas en relaciones públicas. A fin de determinar si estas aplicaciones están afectando el comportamiento de planificación y reservas de productos y servicios turísticos, hicimos un estudio basado en el análisis de Burguess y Kerr (2012) dirigida a turistas portugueses

Comparative gene expression analysis of susceptible and resistant near-isogenic lines in common wheat infected by Puccinia triticina

Gene expression after leaf rust infection was compared in near-isogenic wheat lines differing in the Lr10 leaf rust resistance gene. RNA from susceptible and resistant plants was used for cDNA library construction. In total, 55 008 ESTs were sequenced from the two libraries, then combined and assembled into 14 268 unigenes for further analysis. Of these ESTs, 89% encoded proteins similar to (E value of < or =10(-5)) characterized or annotated proteins from the NCBI non-redundant database representing diverse molecular functions, cellular localization and biological processes based on gene ontology classification. Further, the unigenes were classified into susceptible and resistant classes based on the EST members assembled from the respective libraries. Several genes from the resistant sample (14-3-3 protein, wali5 protein, actin-depolymerization factor and ADP-ribosylation factor) and the susceptible sample (brown plant hopper resistance protein, caffeic acid O-methyltransferase, pathogenesis-related protein and senescence-associated protein) were selected and their differential expression in the resistant and susceptible samples collected at different time points after leaf rust infection was confirmed by RT-PCR analysis. The molecular pathogenicity of leaf rust in wheat was studied and the EST data generated made a foundation for future studies