Influence of fungicide application and vine age on trichoderma diversity as source of biological control agents

Fungi from the genus Trichoderma have a worldwide distribution and are commonly found in agricultural lands. Further, it has been described as a non-virulent and symbiont microorganism that can contribute to minimize the pernicious effects of pathogens. In the present work we have isolated Trichoderma spp. from bark of grapevine in different orchards in order to determine the influence of fungicide application and vine age on Trichoderma diversity in plant. An opposite correlation between the number of fungicides sprayed per campaign and the diversity of Trichoderma spp. isolates was found. Moreover, the older are grapevine plants the higher is the diversity of Trichoderma spp. isolates. The different Trichoderma strains isolated were tested against Phaeoacremonium minimum, a grapevine trunk pathogen, to evaluate their biocontrol capacity. Three Trichoderma strains shown a significant capacity to control P. minimum and were selected as candidates to be used as biological control agents. In addition, a rapid and easy method for isolating Trichoderma spp. from grapevine plants has been developed, which allowed to determine that the reduction in the amount of pesticide use, together with the preservation of old vineyards, lead to healthier agroecosystems containing higher levels of beneficial microorganisms

Vineyard Management and Physicochemical Parameters of Soil Affect Native <i>Trichoderma</i> Populations, Sources of Biocontrol Agents against <i>Phaeoacremonium minimum</i>

Native strains of Trichoderma in vineyard soil represent an opportunity for reducing the incidence of grapevine trunk diseases (GTDs) in vineyards. Moreover, its relationship with the environment (physicochemical soil characteristics and farming management practices) remains unclear. In the current study, a survey was carried out on farming management used by viticulturists, and soil samples were studied to analyze their physicochemical properties and to isolate Trichoderma strains. Later, statistical analyses were performed to identify possible correlations between Trichoderma populations, soil management and soil characteristics. In addition, in vitro tests, including antibiosis and mycoparasitism, were performed to select those Trichoderma strains able to antagonize Phaeoacremonium minimum. In this study a positive correlation was found between the iron content and pH in the soil, and a lower pH increases Trichoderma populations in soils. Vineyard management also affects Trichoderma populations in the soil, negatively in the case of fertilization and tillage and positively in the case of herbicide spraying. Two Trichoderma native strains were selected as potential biocontrol agents (Trichoderma gamsii T065 and Trichoderma harzianum T087) using antibiosis and mycoparasitism as mechanisms of action. These results led to the conclusion that native Trichoderma strains hold great potential as biological control agents and as producers of secondary metabolites

The Influence of Temperature on the Growth, Sporulation, Colonization, and Survival of Trichoderma spp. in Grapevine Pruning Wounds

Trichoderma is a genus of fungi used for the biological control of plant diseases and a large number of its bio-formulates are available in the market. However, its efficacy under field conditions remains unclear, especially for the protection of grapevine plants against Grapevine Trunk Diseases (GTDs). These diseases are caused by a complex of fungal pathogens whose main point of entrance into the affected plants is through pruning wounds. In this research, different Trichoderma native strains have been evaluated according to their ability to grow at different temperatures and their capacity to colonize pruning wounds in adverse climatic conditions. Strains from section Trichoderma have adapted to cooler conditions. On the other hand, strains from clade Harzianum/Virens grow at higher temperatures. However, differences can also be found between strains inside the same clade/section. Native strains were able to colonize more than 70% of vine pruning wounds in winter conditions. The Trichoderma strain T154 showed a significantly higher re-isolation degree from vine plants and its concentration was optimized for spraying onto vine plants. In conclusion, Trichoderma native strains are better adapted to survive in a changing environment, and they could give better protection to grapevine plants in co-evolution with each specific vineyard

Influence of Physicochemical Characteristics of Bean Crop Soil in <i>Trichoderma</i> spp. Development

Spain has ranked 6th on the harvested bean area and 8th in bean production in the European Union (EU). The soils of this area have mixed silt loam and sandy loam texture, with moderate clay content, neutral or acidic pH, rich in organic matter and low carbonate levels, providing beans with high water absorption capacity and better organoleptic qualities after cooking. Similar to other crops, it is attacked by some phytopathogens. Hitherto, chemical methods have been used to control these organisms. However, with the Reform of the Community Agrarian Policy in the EU, the number of authorized plant protection products has been reduced to prevail food security, as well as to be sustainable in the long term, giving priority to the non-chemical methods that use biological agents, such as Trichoderma. This study aimed to investigate the relative importance of various crop soil parameters in the adaptation of Trichoderma spp. autoclaved soils (AS) and natural soils (NS) from the Protected Geographical Indication (PGI) “Alubia La Bañeza—León” that were inoculated with Trichoderma velutinum T029 and T. harzianum T059 and incubated in a culture chamber at 25 °C for 15 days. Their development was determined by quantitative PCR. Twelve soil samples were selected and analyzed from the productive zones of Astorga, La Bañeza, La Cabrera, Esla-Campos and Páramo. Their physicochemical characteristics were different by zone, as the texture of soils ranged between sandy loam and silt loam and the pH between strongly acid and slightly alkaline, as well as the organic matter (OM) concentration between low and remarkably high. Total C and N concentrations and their ratio were between medium and high in most of the soils and the rest of the micronutrients had an acceptable concentration except for Paramo’s soil. Both Trichoderma species developed better in AS than in NS, T. velutinum T029 grew better with high levels of OM, total C, ratio C:N, P, K, Fe, and Zn than T. harzianum T059 in clay soils, with the highest values of cation exchange capacity (CEC), pH, Ca, Mg and Mn. These effects were validated by Canonical Correlation Analysis (CCA), texture, particularly clay concentration, OM, electrical conductivity (EC), and pH (physical parameters) and B and Cu (soil elements) are the main factors explaining the influence in the Trichoderma development. OM, EC, C:N ratio and Cu are the main soil characteristics that influence in T. velutinum T029 development and pH in the development of T. harzianum T059

Effect of Farnesol in Trichoderma Physiology and in Fungal&ndash;Plant Interaction

Farnesol is an isoprenoid intermediate in the mevalonate (MVA) pathway and is produced by the dephosphorylation of farnesyl diphosphate. Farnesol plays a central role in cell growth and differentiation, controls production of ubiquinone and ergosterol, and participates in the regulation of filamentation and biofilm formation. Despite these important functions, studies of farnesol in filamentous fungi are limited, and information on its effects on antifungal and/or biocontrol activity is scarce. In the present article, we identified the Trichoderma harzianum gene dpp1, encoding a diacylglycerol pyrophosphatase that catalyzes production of farnesol from farnesol diphosphate. We analyzed the function of dpp1 to address the importance of farnesol in Trichoderma physiology and ecology. Overexpression of dpp1 in T. harzianum caused an expected increase in farnesol production as well as a marked change in squalene and ergosterol levels, but overexpression did not affect antifungal activity. In interaction with plants, a dpp1-overexpressing transformant acted as a sensitizing agent in that it up-regulated expression of plant defense salicylate-related genes in the presence of a fungal plant pathogen. In addition, toxicity of farnesol on Trichoderma and plants was examined. Finally, a phylogenetic study of dpp1 was performed to understand its evolutionary history as a primary metabolite gene. This article represents a step forward in the acquisition of knowledge on the role of farnesol in fungal physiology and in fungus-environment interactions

La literatura popular impresa en España y en la América Colonial. Formas y temas, géneros, funciones, difusión, historia y teoría

El libro, publicado bajo la dirección del prof. Pedro M. Cátedra, contiene más de treinta monografías sobre la literatura popular impresa de los siglos XV al XVIII en España y América, con acercamientos muy variados y desde las perspectivas de la historia de la cultura popular, la historia de la imprenta, la aculturación tipográfica, los generos editoriales, etc., etc

[Correspondencia de Camilo Díaz Baliño] , 1917-1936

Mss. (algúns en fotocopia) autógrafo e mecanografiadoResumen: Correspondencia recibida por Camilo Díaz Baliño entre os anos 1917-1936 relacionada con asuntos persoais e laboraisBiblioteca de GaliciaForma de ingreso: Depósito. Fuente de ingreso: Díaz Pardo, Isaac. Fecha de ingreso: 2011. Propietario: Herdeiros de Isaac Díaz PardoDixitalización Telefónica-IDP 2012Contén : Cartas de: Manuel Abelenda (1 páx.) -- Cesar Alvarez (1 páx.) -- Carlos Amigo Collía (2 páxs.) -- Banco Hispano-Americano (2 páxs.) -- Alfonso Barreiro (3 páxs.) -- Eliseo Barros Gamallo (1 páx.),(2 páxs.) -- Ramón Beade (2 páxs.) -- Benito(2 páxs.) -- Fernando Blanco(1 páx.) -- José Bouzas y Cardama (1 páx.) -- Albino Bouzó Fernández (1 páx.),(2 páxs) -- José Cabada Vázquez (4 páxs.),(1 páx.),(1 páx.) --Salvador Cabeza (1 páx.) -- Antonio Carballa (1 páx.) -- Leandro y Euxenio Carré (2 páxs.) -- V. Carro (1 páx.) -- Santiago Casares (1 páx.) -- Alvaro Cebreiro (2 páxs.) -- Centro Gallego de Buenos Aires (1 páx.),(1 páx.) -- Compostela (2 páxs.) -- Manolo: Continental (2 páxs.) -- Coral de Ruada (1 páx.),(2 páxs.) -- Amando Cotarelo(1 páx.),(1 páx.) -- Eduardo Dorado Xaneiro (8 páx.) -- Círculo Mercantil e Idustrial: Ramón Fernández (1 páx.) --Virgilio Fernández(3 páxs.) -- Ramón Fernández Mato (2 páxs.) -- B. Ferreiro(1 páx.) -- Jenaro de la Fuente (1 páx.) -- Isaac Fraga: Espéctaculos Empresa Fraga (1 páx.),(1 páx.) -- Antonio Folgar Lema(1 páx.)--Alicio Garcitoral (1 páx.) -- Cándido González Raño (1 páx.) -- Daniel González Rodriguez (2 páxs.),(2 páxs.) -- Edurardo G.del Río (1 páx.) -- Hermanos Hernández (2 páxs.),(1 páx.),(1 páx.),(1 páx.) -- José Iglesias Sánchez (2 páxs.) -- Irmandades da Fala (1 páx.) -- José Silva? (2 páxs.) -- Arturo Longa (1 páx.) -- Casimiro López (1 páx.) -- Edmundo López (1 páx.),(1 páx.) -- Eduardo R. Losada y Rebellón (2 páx.) -- Carlos Maside (1 páx.) -- Enrique Mayer (1 páx.) -- Antonio Méndez Laserna (1 páx.) -- Anselmo Padín (1 páx.) -- Xavier Pardo (1 páx.) -- Partido Republicano Radical Socialista (1 páx.) -- Pérez Bustamante (1 páx.) -- Modesto Piñeiro (2 páxs.) -- Salustiano Portela (2 páxs.) -- José Seijo Rubio (2 páxs.) -- Suarez Picallo (2 páxs.) -- Luis Losada (1 páx), (1 páx.) -- Ricardo Valdés (2 páxs.),(2 páxs.),(2 páxs.),(1 páx.) -- A.Nilo Varela (1 páx.),(2 páxs.),(2 páxs.) -- Juan Varela de Limia (1 páx.) -- Victorino? Varela (1 páx.) -- Jesús Varela (3 páxs.) -- F.Vázquez Suarez (1 páx.) -- Santiago Vidal Gimeno (1 páx.) -- Pedro Vieitez (1 páx.) -- M. Villar (2 páxs.) -- Anónima (1 páx.) -- Anónima (1 páx.