Pathogenicity of multiple Providencia species (Enterobacteriales: Morganellaceae) to the mass-reared Mexican fruit fly (Diptera: Tephritidae)

Mexican fruit fly (Anastrepha ludens (Loew)) (Diptera: Tephritidae) represents a major threat to fruit production in the Western Hemisphere. Sterile insect technique is used to suppress and eradicate wild populations. Success of this control method necessitates weekly production of hundreds of millions of flies, their sterilization by irradiation, and their aerial release. Diet needed to produce large fly numbers are conducive to the spread of bacteria. Pathogenic bacteria were isolated from 3 rearing facilities and from multiple sources: eggs, larvae, pupae and spent diet, and were found to include some isolates identified to the genus Providencia (Enterobacteriales: Morganellaceae). We identified 41 Providencia isolates and tested their pathogenicity to A. ludens. Based on 16s rRNA sequences, 3 groups were clustered into several species of Providencia with varying capacities to affect the Mexican fruit fly production. Isolates putatively identified as P. alcalifaciens/P. rustigianii were all pathogenic causing larval and pupal yield reduction of 46–64% and 37–57%, respectively. Among them, Providencia isolate 3006 was the most pathogenic reducing larval and pupae yield by 73 and 81%, respectively. Isolates identified as P. sneebia were not pathogenic. The final cluster, P. rettgeri/P. vermicola, were variable in pathogenicity with 3 isolates yielding like the control and the rest causing larval and pupal yield reduction of 26–53% and 23–51%, respectively. Isolates putatively identified as P. alcalifaciens/P. rustigianii were more virulent than P. rettgeri/P. vermicola. Accurate identification of species is needed to diagnose and monitor pathogenic versus nonpathogenic Providencia strains

Morganella morganii (Enterobacteriales: Enterobacteriaceae) is a lethal pathogen of Mexican fruit fly (Diptera: Tephritidae) larvae

Tephritid pests, such as the Mexican fruit fly, Anastrepha ludens (Loew), represent a major threat to fruit production worldwide. In order to control these pests, sterile insect technique is used to suppress and eradicate wild populations. For this control method to be successful, hundreds of millions of flies must be produced weekly in mass rearing facilities. The large quantity of artificial diet and close proximity of flies at various life stages allows bacteria from family Enterobacteriaceae, Bacillaceae, Pseudomonadaceae, and others to multiply and spread more easily. In this study, bacteria with a possible pathogenic effect were isolated from Mexican fruit fly eggs and dead Mexican fruit fly larvae. Two strains of bacteria associated with dead and dying larvae were identified using the 16S rRNA sequence as a species of Morganella. Further sequencing of multiple genes and the entire genomes identified both strains as Morganella morganii. Pathogenicity tests were completed to assess this bacterium as a Mexican fruit fly pathogen. Several measures of pathogenicity including effects on larval and pupal weight, adult percent emergence, and flight ability were measured for the 2 strains of Morganella compared against a control. In all cases, the presence of the Morganella strains significantly reduced all quality control measurements compared to the control. Also, at 105 colony forming units per ml or higher levels of inoculum, the presence of Morganella resulted in 100% mortality of larvae. This study illustrates that Morganella morganii is an extremely lethal pathogen of mass reared Mexican fruit flies. - Las moscas tefritidas como la mosca Mexicana de la fruta (Anastrepha ludens Loew), representan un peligro para la producción de la fruta a nivel mundial. Para controlar estas plagas, la técnica del insecto estéril es usada para suprimir y erradicar poblaciones naturales. Para que este método de control tenga éxito, cientos de millones de moscas deben ser producidos en plantas de crianza masiva. La gran cantidad de dieta artificial y la cercanía de moscas en diversos estadios de desarrollo permiten que las bacterias perteneciendo a la familia Entobacteriacea, Baciliiacea, Pseudomonadacea, y otros se multipliquen y diseminen rápidamente. En este estudio, bacterias con posibilidad de ser patogénicas fueron aislados de huevos y larvas muertas de la mosca Mexicana de la fruta. Dos cepas de bacteria aisladas de larvas muertas o moribundas fueron identificados usando secuencias de ARN ribosoma 16S como una especie de Morganella. Adicionalmente, la realización de secuencias de múltiples genes y el genoma entero reveló que las dos cepas de bacteria fueron identificados como Morganella morganii. Pruebas de patogenicidad fueron completadas para determinar la patogenicidad de Morganella hacia la mosca Mexicana de la fruta. Diferentes variables de patogenicidad como el efecto sobre el peso de las larvas y pupas, porcentaje de emergencia de moscas adultas y habilidad de vuelo fueron evaluadas para las cepas de dos Morganella y comparados contra el control. En todos los casos, la presencia de cepas de Morganella redujeron significativamente las medidas de control de calidad comparado con el control. También, al 105 de unidades formadoras de colonias, la presencia de Morganella resultó en una mortalidad del 100% de larvas. Este estudio ilustra que Morganella morganii es un patógeno extremadamente letal para la mosca Mexicana de la fruta

B843: The Ecology, Economics, and Management of Potato Cropping Systems: A Report of the First Four Years of the Maine Potato Ecosystem Project

The bulletin reports on the first four years of the Maine Potato Ecosystem Project, a long-term, multidisciplinary study of alternative crop management strategies. The study site is a 15-acre tract on the northern boundary of the University of Maine\u27s Aroostook Farm in Presque Isle, Maine, divided into 96 main plots that are grouped into four blocks. Each block is an area where soil survey data show similar soil characteristics. Thus, given the same production inputs, the crop output is expected to be the same on each plot within a block. Within each block there are 24 plots to which the different treatments have been randomly assigned. A treatment is a particular combination of the following factors: (1) pest management—conventiorial, reduced input, or biological; (2) potato variety—Atlantic or Superior; and (3) soil management—amended or unamended.https://digitalcommons.library.umaine.edu/aes_bulletin/1025/thumbnail.jp

First report on citrus dry rot in sour orange rootstock in Texas

A grapefruit tree on sour orange rootstock in a residential property in Mission, TX was suspected to have citrus dry root rot disease based on symptoms. The causal organism was isolated from the infected root samples and based on fungal cultural and microscopic morphology and PCR, it was confirmed to be Fusarium solani (Martius) Appel & Wollenweber emend. Snyder & Hansen. A total of 10 healthy sour orange rootstock seedlings were inoculated using conidial suspension of the fungus by the standard root-dip method. After 9 month post inoculation, the inoculated fungus was re-isolated from root and stem sections of these plants. Plants were smaller in size and displayed the classical symptoms of dry rot. The fungal colonies were confirmed to be F. solani based on fungal morphology and PCR. This is the first report of F. solani infecting sour orange rootstock plants in Texas

First report on citrus dry rot in sour orange rootstock in Texas

A grapefruit tree on sour orange rootstock in a residential property in Mission, TX was suspected to have citrus dry root rot disease based on symptoms. The causal organism was isolated from the infected root samples and based on fungal cultural and microscopic morphology and PCR, it was confirmed to be Fusarium solani (Martius) Appel & Wollenweber emend. Snyder & Hansen. A total of 10 healthy sour orange rootstock seedlings were inoculated using conidial suspension of the fungus by the standard root-dip method. After 9 month post inoculation, the inoculated fungus was re-isolated from root and stem sections of these plants. Plants were smaller in size and displayed the classical symptoms of dry rot. The fungal colonies were confirmed to be F. solani based on fungal morphology and PCR. This is the first report of F. solani infecting sour orange rootstock plants in Texas

Trichothecene profiling and population genetic analysis of Gibberella zeae from barley in North Dakota and Minnesota

Gibberella zeae, the principal cause of Fusarium head blight (FHB) of barley, contaminates grains with several mycotoxins, which creates a serious problem for the malting barley industry in the United States, China, and Europe. However, limited studies have been conducted on the trichothecene profiles and population genetic structure of G. zeae isolates collected from barley in the United States. Trichothecene biosynthesis gene (TRI)-based polymerase chain reaction (PCR) assays and 10 variable number tandem repeat (VNTR) markers were used to determine the genetic diversity and compare the trichothecene profiles of an older population (n = 115 isolates) of G. zeae collected in 1997 to 2000 with a newer population (n = 147 isolates) collected in 2008. Samples were from across the major barley-growing regions in North Dakota and Minnesota. The results of TRI-based PCR assays were further validated using a subset of 32 and 28 isolates of G. zeae by sequence analysis and gas chromatography, respectively. TRI-based PCR assays revealed that all the G. zeae isolates in both populations had markers for deoxynivalenol (DON), and the frequencies of isolates with a 3-acetyldeoxynivalenol (3-ADON) marker in the newer population were ≈11-fold higher than those among isolates in the older population. G. zeae populations from barley in the Midwest of the United States showed no spatial structure, and all the isolates were solidly in clade 7 of G. zeae, which is quite different from other barley-growing areas of world, where multiple species of G. zeae are commonly found in close proximity and display spatial structure. VNTR analysis showed high gene diversity (H = 0.82 to 0.83) and genotypic diversity but low linkage disequilibrium (LD = 0.02 to 0.07) in both populations. Low genetic differentiation (FST = 0.013) and high gene flow (Nm = 36.84) was observed between the two populations and among subpopulations within the same population (Nm = 12.77 to 29.97), suggesting that temporal and spatial variations had little influence on population differentiation in the Upper Midwest. Similarly, low FST (0.02) was observed between 3-ADON and 15-acetyldeoxynivalenol populations, indicating minor influence of the chemotype of G. zeae isolates on population subdivision, although there was a rapid increase in the frequencies of isolates with the 3-ADON marker in the Upper Midwest between the older collection made in 1997 to 2000 and the newer collection made in 2008. This study provides information to barley-breeding programs for their selection of isolates of G. zeae for evaluating barley genotypes for resistance to FHB and DON accumulation

Territorialidades, migración y políticas públicas en el contexto rural latinoamericano

Teniendo como antecedente el interés de investigadores e investigadoras de la Universidad Autónoma del Estado de México (uaem) en los temas de desarrollo, género y participación social, el Cuerpo Académico Procesos Sociales en el Medio Rural del Instituto de Ciencias Agropecuarias y Rurales genera la propuesta de establecer una cooperación académica para el desarrollo científico, social y ambiental de los territorios. Así, se consolida la Red Internacional de Procesos Participativos, Género y Desarrollo Territorial, que de manera interdisciplinaria aborda temas transversales relacionados con los procesos participativos de hombres y mujeres en los diversos espacios productivos, públicos, institucionales y regionales, además de su impacto en temas en el desarrollo de sectores o territorios específicos, especialmente de zonas rurales donde la marginación y la pobreza persisten como factores limitantes para la prosperidad nacional. A esta propuesta de Red se adhieren de manera importante los siguientes Cuerpos Académicos de la uaem: 1) Estudios Agroalimentarios, 2) Desarrollo Social y Político en México y América Latina, 3) Género, Migraciones y Desigualdades, y 4) Sustentabilidad, Territorio y Educación. Además de Grupos de Investigación de Colombia, Ecuador y Chile como Grupo Gestión y Desarrollo Rural de la Universidad Nacional de Colombia (gigdr), Grupo de Investigación del Instituto de Investigaciones del Ecuador, y Grupo de investigación en Migraciones, Representaciones de Género, Lengua, Te- rritorialidad y Exclusión Social de la Universidad Católica del Maule-Chile. Cabe destacar que todos ellos poseen amplia experiencia y reconocimiento en los temas de desarrollo territorial y local. Bajo estas circunstancias surge la idea de publicar un libro, en el que se considera que el territorio es un constructo social complejo y abierto, de dinámica colectiva, donde los actores como la academia, las instituciones y las comunidades locales interactúan en una red de conocimiento y de saberes que permite a los procesos participativos una identidad más precisa, con referentes definidos de encuentro y de interacción, especialmente en zonas rurales de Latinoamérica.Instituto de Ciencias Agropecuarias y Rurales, Centro de Investigación en Ciencias Sociales y Humanidades, Red Internacional de Procesos Participativos,Género y Desarrollo Territoria