Anthropogenic factors control the distribution of a southern conifer phytophthora disease in a peri‐urban area of Northern Patagonia, Argentina

Several mid‐sized urban areas have established boundaries overlapping with the distribution of Austrocedrus chilensis (D.Don) Pic.Serm. & Bizzarri forests in Patagonia. These forests suffer a disease whose primary cause is the aggressive pathogen Phytophthora austrocedri. This study analyzes the factors related to Austrocedrus disease in an urban and peri‐urban environment, showing that anthropogenic factors related to Phytophthora dispersion predominantly influence the disease distribution. The study was developed in urban and suburban areas of San Carlos de Bariloche county (Río Negro Province, Argentina). A database of requests to fell A. chilensis trees, from the Forest Department of Río Negro Province, was cleaned up and improved through satellite images analysis and field sampling. Data were analyzed in order to set up a layer of Austrocedrus disease presence. From this layer, and from anthropogenic and environmental layers (distance to houses, distance to roads, precipitation, slope, aspect, altitude, distance to water courses), a risk model was developed using the Maximum Entropy (MaxEnt) algorithm. In turn, data from the field sampling were assessed by contingency tables and chi square analysis. The results show that disease occurrence in San Carlos de Bariloche county is associated with the insertion of the urban network over areas of native forests. Distance to houses, distance to roads and distance to gardens with irrigation were the most important variables associated with the disease occurrence. A risk model was generated for the study area, which shows the current risk situation for the disease. Urbanization’s advance over the forest modifies key variables related to Phytophthora dispersion, such as the distance from cypress trees to houses and roads, thus progressively increasing the area at risk of becoming diseased. Based on these results, plausible measures and actions are proposed.Fil: Giordana, Guillermo. Dirección de Evaluación Ambiental, Secretaría de Ambiente y Desarrollo Urbano; ArgentinaFil: Kitzberger, Thomas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: la Manna, Ludmila Andrea. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ingeniería - Sede Esquel. Centro de Estudios Ambientales Integrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Evaluation of phenol detoxification by Brassica napus hairy roots, using Allium cepa test

Introduction: Meristematic mitotic cells of Allium cepa constitute an adequate material for cytotoxicity and genotoxicity evaluation of environmental pollutants, such as phenol, which is a contaminant frequently found in several industrial effluents. Results and discussion: In the present work, Brassica napus hairy roots (HR) were used for phenol removal assays. The toxicity of post-removal solutions (PRS) and phenol solutions was analyzed. These HR removed the contaminant with high efficiency (100-80% for phenol solutions containing 10-250 mg/L, respectively). Phenol solutions treated with B. napus HR showed a significant reduction of general toxicity compared to untreated phenol solutions, since the IC50 values were 318. 39 and 229. 02 mg/L, respectively. Moreover, PRS presented lower cytotoxicity and genotoxicity than that found in phenol solutions untreated. The mitotic index (MI) observed in meristematic cells treated with PRS (100 and 250 mg/L of phenol) showed an increase of 35% and 42%, whereas the chromosome aberrations showed a significant decrease. According to these results, B. napus HR cultures could be used for the treatment of solutions contaminated with phenol, since we observed not only high removal efficiency, but also an important reduction of the general toxicity, cytotoxicity, and genotoxicity.Fil: González, Paola Solange. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Maglione, Guillermo A.. Universidad Nacional de Río Cuarto; ArgentinaFil: Giordana, Micaela. Universidad Nacional de Río Cuarto; ArgentinaFil: Paisio, Cintia Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto; ArgentinaFil: Talano, Melina Andrea. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Agostini, Elizabeth. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentin