Grapevine Trunk Diseases (GTDs): Impact on Table Grapes and Wine Vineyards in Chile

This chapter involves the description and information about the main grapevine trunk diseases (GTDs) affecting Vitis vinifera in Chile. There is a complete description of Esca-type disease, bot canker disease affecting more than 7-year-old plants, and Petri disease affecting young plants. Symptom descriptions of GTD diseases are done, and also the principal species as causal agents and the importance of them are analyzed. The dispersal of Botryosphaeriaceae spores is considered, and finally, the principal management measures can be taken in order to avoid or control these important diseases. The information is contrasted with different researches done in the most important countries where these diseases are relevant

El análisis de datos en enfoques biográficos-narrativos: desde los métodos hacia una intencionalidad analítica

El análisis de datos es una etapa crucial en investigaciones cualitativas, influyendo la calidad y aplicabilidad de los resultados obtenidos. Los textos sobre análisis de datos suelen indicar principios generales a seguir, escaseando descripciones detalladas de los procedimientos involucrados. Los investigadores cualitativos privilegian difundir resultados de investigación, presentando muy someramente cómo se realizó el análisis y qué fundamentos epistemológicos lo sustentaron.En este artículo, se presentan tres investigaciones que utilizaron procedimientos analíticos desde enfoques biográficos-narrativos: sobre memoria colectiva de la dictadura militar chilena; transmisión transgeneracional del trauma en nietos de víctimas de prisión política y tortura durante la dictadura chilena; y procesos de transformación de subjetividades en pobladores de sectores populares en Santiago. Se presenta en detalle cómo fue diseñado, ejecutado y recreado el análisis de datos en el desarrollo de los procesos investigativos, problematizando epistemológica y metodológicamente las decisiones tomadas en cada fase.Se propone la intencionalidad analítica como una forma de enfrentar el análisis, considerando tres dimensiones: la reflexividad del investigador y su equipo; una escucha polifónica, la que abre nuevas y múltiples opciones de análisis; y el ejercicio sistemático de escritura como una forma de construcción y divulgación del conocimiento. Estas dimensiones pueden contribuir a dotar de sentido al trabajo el análisis de datos en la investigación cualitativa.Datenanalyse ist ein sensibles Stadium im Rahmen qualitativer Forschung, da sie die Qualität und Anwendbarkeit der Ergebnisse beeinflusst. Texte explizieren in der Regel grundlegende Analyseprinzipien, bleiben aber detaillierte Beschreibung der erforderlichen Vorgehensweisen schuldig. Wie andere Wissenschaftler/innen favorisieren auch qualitative Sozialforscher/innen die Verbreitung ihrer Forschungsergebnisse, indem sie die Analysemodi und deren epistemologische Grundlagen nur kurz skizzieren.In diesem Beitrag werden drei Studien vorgestellt, in denen narrativ-biografische Verfahren zum Einsatz kamen: kollektive Erinnerungen an die chilenische Militärdiktatur, die transgenerationale Weitergabe von Traumen an die Enkel von Opfern politischer Gewalt während der Militärdiktatur sowie subjektive Transformationsprozesse über die Zeit aufseiten der Bewohner/innen armer Distrikte in Santiago. Es werden die analytischen Designs und die Umsetzung der Methoden im Forschungsprozess beschrieben, wobei verdeutlicht wird, vor welchem epistemologischen und methodologischen Hintergrund Entscheidungen in jeder der drei Studien getroffen wurden.Analytische Intentionalität wird als Möglichkeit vorgeschlagen, um 1. die Reflexivität der Forschenden bzw. von Forschungsteams angemessen einzubeziehen, 2. polyphone Lesarten im Sinne BAKHTINs zu nutzen, um neue und multiple Analyseoptionen zu eröffnen und 3. systematische Schreibweisen mit dem Ziel einer besseren Verbreitung von Wissen zu erproben. Dies soll den Prozess der Datenanalyse in qualitativen Studien transparenter machen.Data analysis is crucial in qualitative research, influencing the quality and applicability of the results. Texts on data analysis typically describe general principles to be followed but lack detailed illustrations of the procedures involved. Qualitative researchers favor the dissemination of research results, providing an outline of how the analysis was done, and summarizing the epistemological foundations that sustained it.In this article, three investigations are briefly presented, each of which utilized analytical procedures from biographical-narrative approaches: collective memory of the Chilean dictatorship, transgenerational transmission of trauma in grandchildren of victims of political imprisonment and torture during dictatorship, and processes of transformation over time of the subjectivities of the residents of poor neighborhoods in Santiago. Detailed descriptions are presented of how data analysis was designed, executed, and reproduced during the investigations, problematizing from an epistemological and a methodological point of view the decisions made at each step.Analytical intentionality is proposed as a way to deal with analysis considering three dimensions: the reflexivity of the researcher and research team, a polyphonic listening in the BAKHTINian sense that opens new and multiple options for analysis, and a systematic writing exercise as a way of building and disseminating knowledge. These dimensions can help to make sense of the work of data analysis in qualitative research

PRINCIPALES HONGOS FITOPATOGENOS ASOCIADOS A BULBOS ALMACENADOS DE AJO ELEFANTE (Allium ampeloprasum var. holmense) DE LA ZONA DE QUILLOTA Y NOGALES (CHILE)

Se presentan los primeros antecedentes fitopatológicos referentes a una prospección de hongos presentes en bulbos almacenados y plantas deAllium ampeloprasum var. holmense (ajo elefante) provenientes de las zonas de Quillota y Nogales (V Región). A partir de bulbos con diferentes lesiones,se realizaron aislamientos fúngicos correspondientes a lossiguientes taxa: Penicillium hirsutum, P.aurantiogriseum, P.echinulatum, P.funiculosum, P.rugulosum, Fusarium oxysporum y Embellisia allii. Estos se inocularon para efectuar pruebas de patogenicidad; tantoen bulbos como en plantas en maceta (salvo Penicillium spp.).Los resultados obtenidos en bulbos almacenados indicaron que el principal problema en las muestras analizadas fue Penicillium hirsutum, asociado a lesiones inicialmente hendidas, secas, rodeadas de unhalo blanquecino, presentando al cabo de 7 días una pudrición blanda acuosa que involucraba la totalidad del bulbo, apareciendo posteriormente el moho azul en las lesiones. Los problemas de importancia secundaria para esta especie vegetal en la zona estudiadafueron Fusarium oxysporum y Embellisia allii. El principal problema en las plantas en maceta fue E. allii, el cual bajo condiciones de humedadprevia y en períodos cercanos a la cosecha, afectó al bulbo cubriéndolo de un micelio negro.

New strains obtained after UV treatment and protoplast fusion of native Trichoderma harzianum: their biocontrol activity on Pyrenochaeta lycopersici

Indexación: ScieloThe obtainment of 30 new strains from native Trichoderma harzianum after UV light irradiation (UV-A and UV-C), and of 82 strains resulted from protoplast fusion were accomplished. The new strains, initially selected for their growing rate under low temperature and high pH conditions, as well as for their innocuousness on tomato plants, were tested for in vitro inhibition of Pyrenochaeta lycopersici in dual cultures and due to secretion of volatile and diffusible metabolites. All the UV-A and UV-C selected candidate mutants were innocuous to tomato plants, but none of them showed improvement in their biocontrol activity on P. lycopersici. Th12A20.1 increased 1.3 and 1.9 fold the total fresh weight of Fortaleza tomato plants when compared to its parental strains Th12 and Th11, respectively. The selected candidate mutants obtained through protoplast fusion were also innocuous to tomato plants, but only ThF1-2 and ThF4-4 inhibited 1.3 fold (in dual cultures) and 5 fold (due to secretion of volatile metabolites) the growth of P. lycopersici, respectively, in relation to the mean inhibitory effect of both parents. Therefore, these candidate mutants could be included in experiments under field conditions

Selection of bioantagonistic bacteria to be used in biological control of Rhizoctonia solani in tomato

Bacteria from the rhizoplane and surrounding soil of healthy and Rhizoctonia solani diseased tomato plants, cropped in greenhouse of the V Region of Chile, were collected. The best bacterial strains, based on their ability to control development of three R. solani isolates (identified as belonging to the anastomosis groups AG-2-1, AG-4), were identified as B. subtilis (one isolate) and B. lentimorbus (two different isolates). All bacterial isolates resulted effective for the in vitro control of growth of all R. solani isolates, where the control mechanisms used by the bacteria do not involve the secretion of fungal cell wall hydrolytic enzymes. R. solani AG-2-1 was more sensitive than R. solani AG-4. On the other hand, all bacteria grew well in conditions similar to those that can be found at the field level (considering pH, salinity, Fe3+ and temperature) and showed a good capacity of tomato root colonization. These results suggest that the B. subtilis and B. lentimorbus isolates studied have an excellent potential to be used as biocontrol agents of R. solani in tomato greenhouses at the field level

Genetic and Phenotypic Characterization of Indole-Producing Isolates of Pseudomonas syringae pv. actinidiae Obtained From Chilean Kiwifruit Orchards

In recent years, Chilean kiwifruit production has been affected by the phytopathogen Pseudomonas syringae pv. actinidiae (Psa), which has caused losses to the industry. In this study, we report the genotypic and phenotypic characterization of 18 Psa isolates obtained from Chilean kiwifruits orchards between 2012 and 2016 from different geographic origins. Genetic analysis by multilocus sequence analysis (MLSA) using four housekeeping genes (gyrB, rpoD, gltA, and gapA) and the identification of type III effector genes suggest that the Chilean Psa isolates belong to the Psa Biovar 3 cluster. All of the isolates were highly homogenous in regard to their phenotypic characteristics. None of the isolates were able to form biofilms over solid plastic surfaces. However, all of the isolates formed cellular aggregates in the air–liquid interface. All of the isolates, except for Psa 889, demonstrated swimming motility, while only isolate Psa 510 demonstrated swarming motility. The biochemical profiles of the isolates revealed differences in 22% of the tests in at least one Psa isolate when analyzed with the BIOLOG system. Interestingly, all of the isolates were able to produce indole using a tryptophan-dependent pathway. PCR analysis revealed the presence of the genes aldA/aldB and iaaL/matE, which are associated with the production of indole-3-acetic acid (IAA) and indole-3-acetyl-3-L-lysine (IAA-Lys), respectively, in P. syringae. In addition, IAA was detected in the cell free supernatant of a representative Chilean Psa strain. This work represents the most extensive analysis in terms of the time and geographic origin of Chilean Psa isolates. To our knowledge, this is the first report of Psa being able to produce IAA. Further studies are needed to determine the potential role of IAA in the virulence of Psa during kiwifruit infections and whether this feature is observed in other Psa biovars

New strains obtained after UV treatment and protoplast fusion of native Trichoderma harzianum : their biocontrol activity on Pyrenochaeta lycopersici

The obtainment of 30 new strains from native Trichoderma harzianum after UV light irradiation (UV-A and UV-C), and of 82 strains resulted from protoplast fusion were accomplished. The new strains, initially selected for their growing rate under low temperature and high pH conditions, as well as for their innocuousness on tomato plants, were tested for in vitro inhibition of Pyrenochaeta lycopersici in dual cultures and due to secretion of volatile and diffusible metabolites. All the UV-A and UV-C selected candidate mutants were innocuous to tomato plants, but none of them showed improvement in their biocontrol activity on P. lycopersici. Th12A20.1 increased 1.3 and 1.9 fold the total fresh weight of Fortaleza tomato plants when compared to its parental strains Th12 and Th11, respectively. The selected candidate mutants obtained through protoplast fusion were also innocuous to tomato plants, but only ThF1-2 and ThF4-4 inhibited 1.3 fold (in dual cultures) and 5 fold (due to secretion of volatile metabolites) the growth of P. lycopersici, respectively, in relation to the mean inhibitory effect of both parents. Therefore, these candidate mutants could be included in experiments under field conditions

Pudrición negra en raicillas de palto (Persea americana Mill.) por Cylindrocarpon destructans: patogenicidad y aspectos epidemiologicos

En un vivero comercial de Quillota (V Región, Chile), durante los años 1994 y 1995 se produjo en plantas de de palto (Persea americana Mill.) un súbito decaimiento de éstas, caracterizado por sintomas  iniciales de marchitez, pérdida de turgor de las hojas, asociada a clorosis y necrosis marginal y al mismo tiempo, a nivel de las raíces, se observó una pudrición severa de color café oscuro a negro.  Sólo por concepto de estos problemas, se destruyeron 22.000 plantas en dos años. A partir de la zona de avance de las lesiones radiculares, se aisló en forma consistente colonias de Cylindrocarpon destructans, no detectándose representantes del género Phytophthora. Con el propósito de determinar la posible fuente de inóculo, se efectuaron aislamientos desde el sustrato empleado, sus diferentes componente y de semillas, recuperándose este patógeno sólo desde la arena de río y suelo de tranque.De acuerdo con los resultados obtenidos a partir de los diferentes aislamientos, las pruehas de patogenicidad y los síntomas observados, se considera a C. destructans como el agente causal de una nueva enfermedad que afecta a plantas de palto en vivero