Seed-borne diseases in pasture grasses and legumes: state of the art and gaps in knowledge

Information on fungal seed-borne diseases on main pasture grasses and legumes from the literature was reviewed. These diseases reduce biomass production, quality of forage, and persistence due to progressive plant mortality. The main fungal pathogens associated with forage seeds belong to the orders Hypocreales, Pleosporales, and Helotiales in the phylum Ascomycota. Hypocreales includes the genus Fusarium, which reduces seedling establishment, and contaminates plant tissues with mycotoxins. Pleosporales includes many genera associated with seeds of legumes (Leptosphaerulina and Ascochyta), grasses (Bipolaris, Pyrenophora, Curvularia, Drechslera, Alternaria, Exserohilum, and Phoma), and both (Stemphylium). Some fungal genera within this order induce the accumulation of coumestans (leafspot-producing fungi) or produce secondary metabolites that contaminate tissues (Alternaria). Within Helotiales, the main genera are Sclerotinia (affecting mainly legumes), Clarireedia and Gloeotinia (affecting grasses). Pyricularia (order Magnaporthales), Colletotrichum (order Glomerellales), and Cercospora (order Mycosphaerellales) also include seed-borne fungi that provoke diseases on forage species as well as Rhizoctonia (order Cantharellales) and Ustilago (order Ustilaginales) which belong to the phylum Basidiomycota. These pathogens affect pastures by (i) compromising seedling establishment at early stages and (ii) constraining growth by reducing yield and seed quality at later stages. Future research should address (i) generation of reliable data on forage yield loss due to seed-borne diseases, (ii) assessment of the interaction between seed-borne pathogens and other biotic and/or abiotic stresses, (iii) delve into the study of the role of wild and/or cultivated forage species as inoculum reservoirs of pathogens, and (vi) shed light on the contamination issue due to mycotoxins generation.Fil: Pérez Pizá, María Cecilia. Universidad del Salvador; ArgentinaFil: Striker, Gustavo Gabriel. Universidad de Buenos Aires; Argentina. University of Western Australia; Australia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Stenglein, Sebastian Alberto. Universidad Nacional del Centro de la Provincia de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Cientifico Tecnolológico Mar del Plata. Instituto de Investigaciones en Biodiversidad y Biotecnología. Laboratorio de Biología Funcional y Biotecnología; Argentin

Selection of alfalfa genotypes for resistance to the foliar pathogen Curvularia geniculata

ABSTRACT Foliar diseases impose severe restrictions on the persistence and productivity of Medicago sativa, both of which may be increased by developing disease resistant and more competitive genotypes that can improve pasture quality. We found Curvularia geniculata as the principal alfalfa foliar pathogen in the Brazilian state of Rio Grande do Sul (RS). Growth chamber experiments evaluated the resistance of alfalfa genotypes ‘E1C4’, ‘CPPSul’, ‘ABT 805’ and ‘CUF-101’ to C. geniculata as compared the control ‘Crioula’ genotype. These genotypes were also evaluated in field trials at a sea level site in Eldorado do Sul in central RS and at two sites £200 m above sea level, one in Bagé municipality in south west RS and the other at a farm near the town of Alto Feliz in north east RS. Plants were spray-inoculated with 1.6 x 106 ml-1 of C. geniculata spores and visually evaluated for leaf damage 14 days later. The C. geniculata infection rates varied from zero to 100%. Alfalfa persistence and forage mean dry mass (DM) production at the Eldorado site were measured during different seasons from November 2013 to January 2015 by calculating the incidence of invasive plants and morphologically separating leaves from stems and calculating both leaf and stem DM. Data were analysed using mixed statistical models. The best results for persistence and forage DM were shown by the ‘CPPSul’ genotypes (DM = 16,600 kg ha-1) and ‘Crioula’ (DM = 15,750 kg ha-1). These two genotypes will be used for subsequent investigations and selection cycles

VORCOR: A computer program for calculating characteristics of wings with edge vortex separation by using a vortex-filament and-core model

A computer code base on an improved vortex filament/vortex core method for predicting aerodynamic characteristics of slender wings with edge vortex separations is developed. The code is applicable to camber wings, straked wings or wings with leading edge vortex flaps at subsonic speeds. The prediction of lifting pressure distribution and the computer time are improved by using a pair of concentrated vortex cores above the wing surface. The main features of this computer program are: (1) arbitrary camber shape may be defined and an option for exactly defining leading edge flap geometry is also provided; (2) the side edge vortex system is incorporated

Providence Independent, V. 2, No. 26, Thursday, December 7, 1876

[4] p. “Independent in all Things – Neutral in Nothing.” Newspaper published in Trappe, Pa. Weekly. Contains local, national and international news, fiction and advertisements.https://digitalcommons.ursinus.edu/providence/1025/thumbnail.jp

Official Register of the United States, containing a list of the officers and employes in the Civil, Military, and Naval Service on the first of July, 1893; together with a list of vessels belonging to the United States. Volume II, Pt. 2 of 2.

Official Register of the U.S. 1 July. HMD 29 (pts. 1 and 2), 53-2. v2-3. 2779p. [3230-3231] Lists all employees of the Indian service

The Independent, V. 28, Thursday, February 12, 1903, [Whole Number: 1441]

[4] p. Accept the Truth Wherever Found - Dare to Maintain the Truth. Newspaper published in Collegeville, Pa. Weekly. Contains local, national and international news, fiction and advertisements.https://digitalcommons.ursinus.edu/independent/1243/thumbnail.jp

Streptococcus pneumoniae’s Virulence and Host Immunity: Aging, Diagnostics, and Prevention

Streptococcus pneumoniae is an infectious pathogen responsible for millions of deaths worldwide. Diseases caused by this bacterium are classified as pneumococcal diseases. This pathogen colonizes the nasopharynx of its host asymptomatically, but overtime can migrate to sterile tissues and organs and cause infections. Pneumonia is currently the most common pneumococcal disease. Pneumococcal pneumonia is a global health concern and vastly affects children under the age of five as well as the elderly and individuals with pre-existing health conditions. S. pneumoniae has a large selection of virulence factors that promote adherence, invasion of host tissues, and allows it to escape host immune defenses. A clear understanding of S. pneumoniae’s virulence factors, host immune responses, and examining the current techniques available for diagnosis, treatment, and disease prevention will allow for better regulation of the pathogen and its diseases. In terms of disease prevention, other considerations must include the effects of age on responses to vaccines and vaccine efficacy. Ongoing work aims to improve on current vaccination paradigms by including the use of serotype-independent vaccines, such as protein and whole cell vaccines. Extending our knowledge of the biology of, and associated host immune response to S. pneumoniae is paramount for our improvement of pneumococcal disease diagnosis, treatment, and improvement of patient outlook

Winona Daily News

https://openriver.winona.edu/winonadailynews/1649/thumbnail.jp