Genome-wide DNA-(de)methylation is associated with Noninfectious Bud-failure exhibition in Almond (Prunus dulcis [Mill.] D.A.Webb).

Noninfectious bud-failure (BF) remains a major threat to almond production in California, particularly with the recent rapid expansion of acreage and as more intensive cultural practices and modern cultivars are adopted. BF has been shown to be inherited in both vegetative and sexual progeny, with exhibition related to the age and propagation history of scion clonal sources. These characteristics suggest an epigenetic influence, such as the loss of juvenility mediated by DNA-(de)methylation. Various degrees of BF have been reported among cultivars as well as within sources of clonal propagation of the same cultivar. Genome-wide methylation profiles for different clones within almond genotypes were developed to examine their association with BF levels and association with the chronological time from initial propagation. The degree of BF exhibition was found to be associated with DNA-(de)methylation and clonal age, which suggests that epigenetic changes associated with ageing may be involved in the differential exhibition of BF within and among almond clones. Research is needed to investigate the potential of DNA-(de)methylation status as a predictor for BF as well as for effective strategies to improve clonal selection against age related deterioration. This is the first report of an epigenetic-related disorder threatening a major tree crop

Phenotypic diversity among local Spanish and foreign peach and nectarine [Prunus persica (L.) Batsch] accessions

17 Pags., 7 Tabls., 1 Fig. The definitive version is available at: http://link.springer.com/journal/10681Phenotypic data for tree and fruit characteristics was collected over three consecutive years from a germplasm collection of 94 peach and nectarine accessions representing both traditional Spanish as well as foreign cultivars with widespread global plantings. All accessions were grown at the Experimental Station of Aula Dei located in the Ebro Valley (Northern Spain, Zaragoza) under a Mediterranean climate. Tree traits evaluated included bloom and harvest date, vigor, yield, yield efficiency and flower and leaf characteristics. Fruit traits included fresh weight, firmness, soluble solids, titratable acidity, levels of individual soluble sugars (sucrose, glucose, fructose and sorbitol), vitamin C, total phenolics, flavonoids, anthocyanins, relative antioxidant capacity and ripening index. Extensive variability was observed for most qualitative and quantitative traits with significant correlations identified between many traits. While the traditional Spanish accessions demonstrated good adaptability to the northern Spain evaluation site, opportunities for continued improvement in tree and fruit quality traits were demonstrated by an extensive phenotypic variability within the germplasm collection.This study was funded by the Spanish Ministry of Science and Innovation (MICINN) grants AGL2005-05533, AGL2008-00283 and AGL2011-24576, and RFP 2009-00016 cofunded by FEDER and the Regional Government of Aragon (A44). C. Font was supported by a JAE fellowship from Consejo Superior de Investigaciones Científicas (CSIC).Peer reviewe

Phenotypic diversity among local Spanish and foreign peach and nectarine [Prunus persica (L.) Batsch] accessions

17 Pags., 7 Tabls., 1 Fig. The definitive version is available at: http://link.springer.com/journal/10681Phenotypic data for tree and fruit characteristics was collected over three consecutive years from a germplasm collection of 94 peach and nectarine accessions representing both traditional Spanish as well as foreign cultivars with widespread global plantings. All accessions were grown at the Experimental Station of Aula Dei located in the Ebro Valley (Northern Spain, Zaragoza) under a Mediterranean climate. Tree traits evaluated included bloom and harvest date, vigor, yield, yield efficiency and flower and leaf characteristics. Fruit traits included fresh weight, firmness, soluble solids, titratable acidity, levels of individual soluble sugars (sucrose, glucose, fructose and sorbitol), vitamin C, total phenolics, flavonoids, anthocyanins, relative antioxidant capacity and ripening index. Extensive variability was observed for most qualitative and quantitative traits with significant correlations identified between many traits. While the traditional Spanish accessions demonstrated good adaptability to the northern Spain evaluation site, opportunities for continued improvement in tree and fruit quality traits were demonstrated by an extensive phenotypic variability within the germplasm collection.This study was funded by the Spanish Ministry of Science and Innovation (MICINN) grants AGL2005-05533, AGL2008-00283 and AGL2011-24576, and RFP 2009-00016 cofunded by FEDER and the Regional Government of Aragon (A44). C. Font was supported by a JAE fellowship from Consejo Superior de Investigaciones Científicas (CSIC).Peer reviewe

Application of genomic and quantitative genetic tools to identify candidate resistance genes for brown rot resistance in peach.

The availability of a complete peach genome assembly and three different peach genome sequences created by our group provide new opportunities for application of genomic data and can improve the power of the classical Quantitative Trait Loci (QTL) approaches to identify candidate genes for peach disease resistance. Brown rot caused by Monilinia spp., is the most important fungal disease of stone fruits worldwide. Improved levels of peach fruit rot resistance have been identified in some cultivars and advanced selections developed in the UC Davis and USDA breeding programs. Whole genome sequencing of the Pop-DF parents lead to discovery of high-quality SNP markers for QTL genome scanning in this experimental population. Pop-DF created by crossing a brown rot moderately resistant cultivar 'Dr. Davis' and a brown rot resistant introgression line, 'F8,1-42', derived from an initial almond × peach interspecific hybrid, was evaluated for brown rot resistance in fruit of harvest maturity over three seasons. Using the SNP linkage map of Pop-DF and phenotypic data collected with inoculated fruit, a genome scan for QTL identified several SNP markers associated with brown rot resistance. Two of these QTLs were placed on linkage group 1, covering a large (physical) region on chromosome 1. The genome scan for QTL and SNP effects predicted several candidate genes associated with disease resistance responses in other host-pathogen systems. Two potential candidate genes, ppa011763m and ppa026453m, may be the genes primarily responsible for M. fructicola recognition in peach, activating both PAMP-triggered immunity (PTI) and effector-triggered immunity (ETI) responses. Our results provide a foundation for further genetic dissection, marker assisted breeding for brown rot resistance, and development of peach cultivars resistant to brown rot

Folded Resonant Horns for Power Ultrasonic Applications

Folded horns have been conceived as alternatives to straight horns used as resonators and strain amplifiers in power ultrasonic systems. Such systems are used for cleaning, welding, soldering, cutting, and drilling in a variety of industries. In addition, several previous NASA Tech Briefs articles have described instrumented drilling, coring, and burrowing machines that utilize combinations of sonic and ultrasonic vibrational actuation. The main advantage of a folded horn, relative to a straight horn of the same resonance frequency, is that the folded horn can be made shorter (that is, its greatest linear dimension measured from the outside can be made smaller). Alternatively, for a given length, the resonance frequency can be reduced. Hence, the folded-horn concept affords an additional degree of design freedom for reducing the length of an ultrasonic power system that includes a horn

Probing Hyperbolic and Surface Phonon-Polaritons in 2D materials using Raman Spectroscopy

The hyperbolic dispersion relation of phonon-polaritons (PhPol) provides high-momentum states, highly directional propagation, subdiffractional confinement, large optical density of states, and enhanced light-matter interactions. In this work, we use Raman spectroscopy in the convenient backscattering configuration to probe PhPol in GaSe, a 2D material presenting two hyperbolic regions separated by a \textit{double} reststrahlen band. By varying the incidence angle, dispersion relations are revealed. Raman spectra calculations confirm the observation of one surface and two extraordinary guided polaritons and matches the evolution of PhPol frequency as a function of confinement. Resonant excitation close to the excitonic state singularly exalts the scattering efficiency of PhPol. Raman spectroscopy of PhPol in non-centrosymmetry 2D materials does not require any wavevector matching strategies. Widely available, it may accelerate the development of MIR nanophotonic devices and applications

QUBIC: The QU Bolometric Interferometer for Cosmology

One of the major challenges of modern cosmology is the detection of B-mode polarization anisotropies in the CMB. These originate from tensor fluctuations of the metric produced during the inflationary phase. Their detection would therefore constitute a major step towards understanding the primordial Universe. The expected level of these anisotropies is however so small that it requires a new generation of instruments with high sensitivity and extremely good control of systematic effects. We propose the QUBIC instrument based on the novel concept of bolometric interferometry, bringing together the sensitivity advantages of bolometric detectors with the systematics effects advantages of interferometry. Methods: The instrument will directly observe the sky through an array of entry horns whose signals will be combined together using an optical combiner. The whole set-up is located inside a cryostat. Polarization modulation will be achieved using a rotating half-wave plate and interference fringes will be imaged on two focal planes (separated by a polarizing grid) tiled with bolometers. We show that QUBIC can be considered as a synthetic imager, exactly similar to a usual imager but with a synthesized beam formed by the array of entry horns. Scanning the sky provides an additional modulation of the signal and improve the sky coverage shape. The usual techniques of map-making and power spectrum estimation can then be applied. We show that the sensitivity of such an instrument is comparable with that of an imager with the same number of horns. We anticipate a low level of beam-related systematics thanks to the fact that the synthesized beam is determined by the location of the primary horns. Other systematics should be under good control thanks to an autocalibration technique, specific to our concept, that will permit the accurate determination of most of the systematics parameters.Comment: 12 pages, 10 figures, submitted to Astronomy and Astrophysic

Physical Fruit Traits in Moroccan Almond Seedlings: Quality Aspects and Post-Harvest Uses

The physical traits of local almond populations from Morocco were studied to characterize their genetic resources and to evaluate the possibility of their commercial valorization. Nut weight ranged between 1.15 and 7.39 g, and kernel weight between 0.54 and 1.85 g, but most accessions were characterized by small kernels, pronounced wrinkles, and double kernels. Although the physical quality of the kernels of these populations was low, they show the possibility of some specialized uses, which could improve their marketable value. The genotypes with favorable values could be incorporated into an almond breeding program as parents to increase the kernel quality.Publishe

Genetic analysis for physical nut traits in almond

Peer ReviewedPublishe