Genetic diversity of the myrtle rust pathogen (Austropuccinia psidii) in the Americas and Hawaii : global implications for invasive threat assessments

Since the myrtle rust pathogen (Austropuccinia psidii) was first reported (as Puccinia psidii) in Brazil on guava (Psidium guajava) in 1884, it has been found infecting diverse myrtaceous species. Because A. psidii has recently spread rapidly worldwide with an extensive host range, genetic and genotypic diversities were evaluated within and among A. psidii populations in its putative native range and other areas of myrtle rust emergence in the Americas and Hawaii. Microsatellite markers revealed several unique multilocus genotypes (MLGs), which grouped isolates into nine distinct genetic clusters [C1–C9 comprising C1: from diverse hosts from Costa Rica, Jamaica, Mexico, Puerto Rico, and USA‐Hawaii, and USA‐California; C2: from eucalypts (Eucalyptus spp.) in Brazil/Uruguay and rose apple (Syzygium jambos) in Brazil; C3: from eucalypts in Brazil; C4: from diverse hosts in USA‐Florida; C5: from Java plum (Syzygium cumini) in Brazil; C6: from guava and Brazilian guava (Psidium guineense) in Brazil; C7: from pitanga (Eugenia uniflora) in Brazil; C8: from allspice (Pimenta dioica) in Jamaica and sweet flower (Myrrhinium atropurpureum) in Uruguay; C9: from jabuticaba (Myrciaria cauliflora) in Brazil]. The C1 cluster, which included a single MLG infecting diverse host in many geographic regions, and the closely related C4 cluster are considered as a “Pandemic biotype,” associated with myrtle rust emergence in Central America, the Caribbean, USA‐Florida, USA‐Hawaii, Australia, China‐Hainan, New Caledonia, Indonesia and Colombia. Based on 19 bioclimatic variables and documented occurrences of A. psidii contrasted with reduced sets of specific genetic clusters (subnetworks, considered as biotypes), maximum entropy bioclimatic modelling was used to predict geographic locations with suitable climate for A. psidii which are at risk from invasion. The genetic diversity of A. psidii throughout the Americas and Hawaii demonstrates the importance of recognizing biotypes when assessing the invasive threats posed by A. psidii around the globe.USDA-Forest Service, RMRS-Forest and Woodlands Ecosystem Program, Western Wildlands Environmental Threat Assessment Center, Special Technology Development Program, State and Private Forestry, Forest Health Protection-Region 5; Conselho Nactional de Desenvolvimento Científico e Tecnológico, Brasil (CNPq); Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG); Research Joint Venture Agreements RMRS 15-JV-11221633-160 (Jane Stewart, Colorado State University) and RMRS 14-JV-11221633-117 (Western Forest Conservation Association).http://wileyonlinelibrary.com/journal/efp2019-02-01hj2018Forestry and Agricultural Biotechnology Institute (FABI)Plant Production and Soil Scienc

Nuevo módulo de consulta de la aplicación P-FOR INIA: el avance de una herramienta interactiva.

El sector forestal uruguayo, ubicado actualmente entre los tres principales sectores agroindustriales exportadores del país, ha enfrentado en los últimos años un incremento del ingreso accidental de nuevos patógenos y plagas forestales, así como de la incidencia y severidad de los problemas sanitarios ya existentes, resultandoambos casos en pérdidas productivas tanto en el volumen como en la calidad de la madera. En este contexto, la detección temprana de plagas y enfermedades forestaleses crucial para el desarrollo de estrategias de manejo dirigidas a mitigar su impacto en plantaciones comerciales. Como material de apoyo para estas actividades se desarrolló inicialmente una serie de cartillas informativas y posteriormente, en el año 2015, una aplicación para teléfonos inteligentes: P-FOR INIA - Guía de Plagasy Enfermedades Forestales en Uruguay, dirigida a personas en contacto con plantaciones forestales y que necesiten identificar, en forma ágil e in situ, los principalesproblemas sanitarios existentes en las mismas

Nueva herramienta en sanidad forestal: aplicación P-FOR para teléfonos inteligentes.

P-FOR es una Guía de Plagas y Enfermedades Forestales en Uruguay que presenta información sobre los principales problemas sanitarios de origen biótico que afectan las plantaciones forestales, en un formato sencillo y amigable para el usuario.Consta básicamente de dos módulos:- Biblioteca: en este módulo se tendrá acceso a la información de las cartillas INIA de ?Reconocimiento a campo de plagas y enfermedades forestales?, con un diseño adecuado para la navegación en pequeñas pantallas, para el acceso fácil a la información e imágenes sobre los diferentes problemas sanitarios reportados para nuestro país.- Guía de Síntomas: en este módulo el usuario será guiado mediante preguntas sobre lo que observa en el rodal o en el árbol, para llegar a la identificación del problema y acceder a información sobre el mismo

Productivity losses caused by Teratosphaeria nubilosa on Eucalyptus globulus and Eucalyptus maidenii in Uruguay. [Resumen].

Teratosphaeria nubilosa severely affects young plantations of Eucalyptus globulus and E. maidenii in Uruguay. This work analyzes theeffect of this pathogen on the growth and survival of both species, based on data from a naturally infected field trial. The degree of defoliation was quantified at 21 months old, and its effects on diameter and mortality were evaluated at 62 months old. Defoliation in E. globulus was higher than in E. maidenii, with an average of 52.5 and 28.8%, respectively. Four years after the epidemic, defoliation classes of 40% or higher had significant growth losses on E. globulus, while losses in E. maidenii were significant when defoliation was 30% or higher. An average loss in DAP of 27.5 % in E. globulus and 12.5 % in E. maidenii was observed. The most affected trees, with 70-80% of defoliation in E. globulus and 60% in E. maidenii, had similar growth loss in both species, suffering a reduction in DAP of 43.9% and 42.5%, respectively. By contrast, the average mortality that occurred between 21 and 62 months old was significantly higher in E. globulus (16.7%) than in E. maidenii (3.3%). Mortality in the higher defoliation classes reached 44.7% on E. globulus and 47.1% on E. maidenii. Although E. globulus showed greater susceptibility to the disease and higher productivity losses, the significant defoliation and growth losses registered in E. maidenii suggest that this species is not as suitable as previously thought to replace E. globulus on sites with high risk of T. nubilosa

INIA SOMBRA: una alternativa para la protección del ganado y para la diversificación productiva.

La instalación de pequeños montes en establecimientos agropecuarios para brindar sombra y abrigo al ganado fue una práctica frecuente en todo el país durantebuena parte del siglo XX. Se estima que existen más de 40.000 hectáreas de este tipo de montes, denominados ?cortinas?, ?granjas? o ?islas?, la mayor parte de los cuales fueron plantadas con eucaliptos colorados (nombre común de algunas especies de Eucalyptus dado por la coloración rojiza de su madera), principalmente con E.camaldulensis y E. tereticornis. El uso generalizado de estas especies se debió a su gran rusticidad (buena adaptación a todo tipo de suelos, tolerancia a sequías y heladas), lo cual contribuyó en gran medida a la buena implantación y sobrevivencia de los montes, incluso en suelos que limitan la adaptación de la mayoríade las especies forestales, como las planicies del este o los suelos de basalto. La utilización de eucaliptos colorados también demostró ser acertada por otro motivo, elde presentar una madera de gran aptitud para diferentes usos. Por su alta densidad y poder calórico su madera es excelente para fines energéticos (leña y carbón). Por otra parte, su gran resistencia y durabilidad hacen que la madera de eucalipto colorado sea muy utilizada para columnas, postes, piques y carpintería rural. A su vez, por su coloración y dureza, la madera de estas especies es muy apreciada para pisos y muebles. En los últimos años se ha retomado el interés de productores agropecuarios en instalar montes de protección para el ganado y/o diversificar su producción con especies forestales que permitan obtener productos dealto valor. Por las características mencionadas anteriormente, los eucaliptos colorados son una de las alternativas más adecuadas para ambos cometidos. Dadoque los montes deben permanecer cerrados al pastoreo hasta que los árboles tengan dos o tres metros de altura, la velocidad de crecimiento inicial es otro de losaspectos a tener en cuenta en la elección de la especie a utilizar. Si bien los eucaliptos colorados tienen aceptable tasa de crecimiento, la misma es menor que lade las especies utilizadas con fines industriales (como E. grandis o E. dunnii). Para mejorar la velocidad de crecimiento, INIA inició en el año 2007 un Plan de Mejoramiento Genético en E. tereticornis. A partir del 2015 y una vez completado el primer ciclo de selección, INIA comenzó a producir semilla mejorada, la que es comercializada con el nombre de INIA SOMBRA. En el año 2018 se inició el segundo ciclo de selección, en el cual se priorizará la mejora del comportamiento sanitario. Se describe a continuación el plan de mejoramiento y el sistema de comercialización de semilla INIA SOMBRA

Biological control of Thaumastocoris peregrinus Carpintero and Dellappé (Heteroptera: Thaumastocoridae): towards the development of a mycoinsecticide. [Resumen].

The bronze bug, Thaumastocoris peregrinus (Heteroptera: Thaumastocoridae) is a small sap feeding hemipteran bug that has becomea serious pest of Eucalyptus plantations worldwide. Affected trees display foliage blight and defoliation, thus reducing photosynthesis and sometimes leading to the death of those highly infested mature trees. The use of entomopathogenic fungi as biological control agents is seen as an environmentally friendly alternative for pest control being chemical control seldom used in commercial forestry because its environmental and economical disadvantages. In this study, naturally occurring entomopathogenic fungi on T. peregrinus were isolated from dead and mycosed insects found in Eucalyptus plantations in Uruguay. Fungal species were identified based on spore and reproductive structures, morphology, culture characteristics, and molecular identification by amplification of the ribosomal DNA comprising ITS1, ITS2 and the 5.8S subunit. The identified entomopathogenic species belong to the genera Beauveria, Isaria, Lecanicillium, Purpureocillium and Pochonia. Bioassays using fiftyeight entomopathogenic fungal isolates from bronze bug and other forestry and agricultural pest insects were performed to determine their pathogenicity and virulence against T. peregrinus. A first in vitro screening was made by spraying 10 7 conidia/ml suspensions onto adults of T. peregrinus reared in mesh cages on detached leaf- bearing twigs of E. tereticornis. Isolates were classified into four categories based on the number of days to reach 90% of mortality. Most of the tested strains (80%) were pathogenic to bronze bug showing different degrees of virulence. For a subset of strains, values of LC 50 and LT50 were determined. In addition, the most promising strains are being subjected to mass production studies in order to identify cost-effective production methods and to select the most stable and virulent formulated strains

Genetic diversity of the myrtle rust pathogen (Austropuccinia psidii) in the Americas and Hawaii: global implications for invasive threat assessments

Since the myrtle rust pathogen (Austropuccinia psidii) was first reported (as Puccinia psidii) in Brazil on guava (Psidium guajava) in 1884, it has been found infecting diverse myrtaceous species. Because A.psidii has recently spread rapidly worldwide with an extensive host range, genetic and genotypic diversities were evaluated within and among A.psidii populations in its putative native range and other areas of myrtle rust emergence in the Americas and Hawaii. Microsatellite markers revealed several unique multilocus genotypes (MLGs), which grouped isolates into nine distinct genetic clusters [C1-C9 comprising C1: from diverse hosts from Costa Rica, Jamaica, Mexico, Puerto Rico, and USA-Hawaii, and USA-California; C2: from eucalypts (Eucalyptus spp.) in Brazil/Uruguay and rose apple (Syzygium jambos) in Brazil; C3: from eucalypts in Brazil; C4: from diverse hosts in USA-Florida; C5: from Java plum (Syzygium cumini) in Brazil; C6: from guava and Brazilian guava (Psidium guineense) in Brazil; C7: from pitanga (Eugenia uniflora) in Brazil; C8: from allspice (Pimenta dioica) in Jamaica and sweet flower (Myrrhinium atropurpureum) in Uruguay; C9: from jabuticaba (Myrciaria cauliflora) in Brazil]. The C1 cluster, which included a single MLG infecting diverse host in many geographic regions, and the closely related C4 cluster are considered as a Pandemic biotype, associated with myrtle rust emergence in Central America, the Caribbean, USA-Florida, USA-Hawaii, Australia, China-Hainan, New Caledonia, Indonesia and Colombia. Based on 19 bioclimatic variables and documented occurrences of A.psidii contrasted with reduced sets of specific genetic clusters (subnetworks, considered as biotypes), maximum entropy bioclimatic modelling was used to predict geographic locations with suitable climate for A.psidii which are at risk from invasion. The genetic diversity of A.psidii throughout the Americas and Hawaii demonstrates the importance of recognizing biotypes when assessing the invasive threats posed by A.psidii around the globe

Fungi associated to bark lesions of Eucalyptus globulus stems in plantations from Uruguay Fungos asociados as lesões da casca do caule de Eucalyptus globulus em plantações no uruguai

Trees with stem bark lesions are frequently observed in Eucalyptus globulus Labill. plantations, particularly in the central west region of Uruguay. These lesions constitute a problem for trunk decortications at harvest and they also facilitate the access of fungi that could cause wood decay. Seven, three and oneyear-old plantations, located at three sites in close proximity were selected. Four types of trunk lesions were present in trees regardless the age of plantation and more than one type was found in each plantation. The aim of this study was to investigate the fungal composition associated with these lesions and compare them to healthy tissues and try to find out the origin of these symptoms. Another purpose was to elucidate the real role of the fungi considered pathogens by means of experimental inoculations. Segments from lesions and healthy tissues yielded 897 fungal isolates belonging to 32 taxa, 681 isolates from bark lesions and 216 from healthy tissues. Both healthy and symptomatic tissues showed similar fungal species composition, but with differences in frequencies of colonization. Cytospora eucalypticola Van der Westhuizen, Botryosphaeria spp., Pestalotiopsis guepinii (Desm.) Stey. and Penicillium spp. were the dominant species isolated. As symptoms were not reproduced after experimental inoculation with Botryosphaeria ribis Grossenb. & Duggar and B. eucalyptorum Crous, & M.J. Wingf, it could be suggested that these lesions were originated by unfavorable environmental conditions. The frost that occurred for several days out of season and flooding may have been involved in the development of bark lesion.<br>As lesões na casca de Eucalyptus globulus Labill. são frequentemente observadas nas plantações da Região Centro-Oeste do Uruguai. Constituem problema para o descortiçamento na colheita e, além disso, facilita a penetraçao de fungos apodrecedores da madeira. Selecionaram-se plantações com 1, 3 e 7 anos de idade, em três localidades próximas, para serem estudadas. Quatro tipos de lesões em caule foram encontrados nas árvores, independentemente da idade destas. Numa mesma plantaçao, havia mais de um tipo de lesão. Os objetivos deste estudo foram identificar a composição da micobiota associada a cada tipo de lesão da casca, compará-la com a dos tecidos sadios e investigar a origem desses sintomas. Outro objetivo foi verificar o papel de alguns colonizadores considerados patógenos, através de inoculações experimentais. Obtiveram-se 897 isolamentos correspondentes, a 32 taxa, 681 de casca lesionada e 216 dos tecidos sadios. Tanto os tecidos lesionados quanto os sadios mostraram composição micobiota específica similar, mas diferentes na frequência de colonização. Cytospora eucalyptica Van der Westhuizen, Botryosphaeria spp., Pestalotiopsis guepinii (Desm.) Stey. e Penicillum spp. foram as espécies dominantes isoladas. Devido à não reprodução dos sintomas depois da inoculação experimental com Botryosphaeria ribis Grossenb. & Duggar e B. eucalyptorum Crous & Wingf, foi sugerido que as lesões aqui estudadas fossem originadas de condições ambientais desfavoráveis. A ocorrência de geadas fora de estação associada à inundação pode ter influenciado o desenvolvimento dessas lesões na casca