Blanca B Landa

Two haplotypes of Xylella fastidiosa subsp. pauca (Xfp) that correlated with their host of origin were identified in a collection of 90 isolates infecting citrus and coffee plants in Brazil, based on a single-nucleotide polymorphism in the gyrB sequence. A new single-nucleotide primer extension (SNuPE) protocol was designed for rapid identification of Xfp according to the host source. The protocol proved to be robust for the prediction of the Xfp host source in blind tests using DNA from cultures of the bacterium, infected plants, and insect vectors allowed to feed on Xfp-infected citrus plants. AMOVA and STRUCTURE analyses of microsatellite data separated most Xfp populations on the basis of their host source, indicating that they were genetically distinct. The combined use of the SNaPshot protocol and three previously developed multilocus SSR markers showed that two haplotypes and distinct isolates of Xfp infect citrus and coffee in Brazil and that multiple, genetically different ...

La protección del sistema radical de plantones de olivo certificados libres de Verti-cillium dahliae de la infección severa por inóculo del patógeno residente en el suelo puede reducir el potencial de Verticilosis en árboles jóvenes y facilitar la expresión en ellos del fenómeno de recuperación sintomatológica. En este trabajo se ha contrastado esta hipótesis con el formulado de biocontrol Bioten®, compuesto por estirpes de los hongos Trichoderma asperellum y T. gamsii, utilizando plantones de olivo 'Picual' micropropagados o autoenraizados e inoculados con V. dahliae defoliante por inmersión radical o transplante a suelo infestado en experimentos repetidos en condiciones contro-ladas y en microparcelas en condiciones naturales. El tratamiento del sistema radical de la planta con Bioten ® al 1% redujo en más de 30% y de forma consistente la severidad de síntomas en plantones inoculados por inmersión radical, y en proporción variable, de 18 a 60%, la incidencia de la enfermed...

Las infecciones de la planta por nematodos fitoparásitos, particularmente Xiphinema index, X. italiae, Meloidogynes spp., Pratylencus spp., y Mesocriconema, spp. se han asociado frecuentemente con sintomas de decaimiento y pérdidas de vigor de los viñedos. En España, las investigaciones sobre nematodos se han concentrado en la Comunidades Autónomas de Canarias, Castilla La Mancha y La Rioja. En Andalucia el estudio de la distribuición y extensiór de los ataques por nematodos fitoparásitos en viñedos es muy limitada, y ha estado circunscrita alos nematodos trasmisores de virus. por ello, el objetivo de esta investigatión es determinar la distribuición y extentión de los ataques por nematodos fitoparásitos en viñedos de Andalucia. Para ello se han levado a cabo prospecciones fitopatológicas de en las zonas de cultivo de vid con Denominatión de origen (Condado de Huelva, Jerez, Montilla-Moriles) en dos fases de desarrollo del cultivo, incluyendo los meses de mayo-junio e septiembre-out...

Gut microbiota, which acts collectively as a fully-integrated organ in the host metabolism, can be shaped by long-term dietary interventions following a specific diet. To study the changes in microbiota after one year's consumption of a Mediterranean diet (Med diet) or a low-fat, high-complex carbohydrates diet (LFHCC diet) in an obese population. Participant swere randomized to receive Med diet (35% fat, 22% monounsaturated) and LFHCC diet (28% fat, 12% monounsaturated). The study was conducted in 20 obese patients (men) within the CORDIOPREV study, an ongoing prospective, randomized, opened, controlled trial in patients with coronary heart disease. We evaluated the bacterial composition and its relationship with the whole fecal and plasma metabolome. The LFHCC diet increased Prevotella and decreased the Roseburia genera while the Med diet decreased Prevotella and increased the Roseburia and Oscillospira genera (P=0.028, 0.002, and 0.016, respectively). The abundance of Parabacteroides distasonis (P=0.025) and Faecalibactrium prausnitzii (P=0.020) increased after the long-term consumption of the Med diet and LFHCC diet, respectively. The changes in the abundance of 7 out of 572 metabolites found in feces, including mainly aminoacids, peptides and the sphingolipid metabolism, could be linked to the changes in the gut microbiota. Our results suggest that a long-term consumption of the Med and LFHCC diets, exert a protective effect on the development of type 2 diabetes by different specific changes in the gut microbiota, increasing the abundance of the Roseburia genus and Faecalibacterium prausnitzii, respectively.

Intestinal microbiota changes may be involved in the development of metabolic syndrome (MetS), which is a multicomponent disorder frequently associated with obesity. The aim of this study was to test the effect of consuming two healthy diets: a Mediterranean diet and a low-fat high-carbohydrate diet, for 2years in the gut microbiota of MetS patients and those in the control group. We analyzed the differences in the bacterial community structure between the groups after 2years of dietary intervention (Mediterranean or low-fat diet) through quantitative polymerase chain reaction using primers, targeting specific bacterial taxa. We observed, at basal time, that the abundance of Bacteroides, Eubacterium and Lactobacillus genera is higher in the control group than in MetS patients, while Bacteroides fragilis group, Parabacteroides distasonis, Bacteroides thetaiotaomicron, Faecalibacterium prausnitzii, Fusobacterium nucleatum, Bifidobacterium longum, Bifidobacterium adolescentis, Ruminococcus flavefaciens subgroup and Eubacterium rectale are depleted in MetS patients (all P values <.05). Additionally, we found that long-term consumption of Mediterranean diet partially restores the population of P. distasonis, B. thetaiotaomicron, F. prausnitzii, B. adolescentis and B. longum in MetS patients (all P values <.05). Our results suggest that the Mediterranean diet could be a useful tool to restore potentially beneficial members of the gut microbiota, although the stability of these changes over time still remains to be assessed.

The present study explored the use of high-resolution thermal, multispectral and hyperspectral imagery as in-dicators of the infections caused by Verticillium wilt (VW) in olive trees and downy mildew (DM) in opium poppy fields. VW, caused by the soil-borne fungus Verticillium dahliae, and DM, caused by the biotrophic obligate oomycete Peronospora arborescens, are the most economically limiting diseases of olive trees and opium poppy, respectively, worldwide. V. dahliae infects the plant by the roots and colonizes its vascular system, blocking water flow and eventually inducing water stress. P. arborescens colonizes the mesophyll, appearing the first symptoms as small chlorotic leaf lesions, which can evolve to curled and thickened tissues and systemic infections that become deformed and necrotic as the disease develops. The work conducted to detect VW and DM infection consisted on the acquisition of time series of airborne thermal, multispectral and hyperspectral imagery using 2-m ...

... humid areas may pose an important constraint on the yield of opium poppy crops in Spain. References: (1) RS Dickey and A. Kelman. Pages 44-59 in: Laboratory Guide for Identification of Plant Pathogenic Bacteria. NW Schaad, ed. The American Phytopathological Society, St. ...