Identificación de hongos fitopatógenos asociados a Brassica oleracea var. Capitata en la granja la Arandela de Armenia, Quindío. / Identification of phytopathogenic fungi associated with Brassica oleracea var. Capitata in the Armenia city, Quindío.

Introducción. Se ha informado que los hongos fitopatógenos representan las principales pérdidas económicas a nivel global en diferentes tipos de cultivos, entre los que se encuentran hortalizas como Brassica Oleracea var. capitata. Objetivos. Identificar los posibles hongos fitopatógenos asociados a Brassica, los signos y síntomas que estos pueden causar, su posible mecanismo de transmisión y comparar cualitativamente el crecimiento de estos en diferentes medios de cultivo. Materiales y métodos. Se aislaron hojas con y sin síntomas, junto con muestras de suelo. En cuanto a la microscopia se visualizaron las partes reproductivas de los hongos para su clasificación taxonómica. Resultados. Se aislaron un total de 17 morfotipos hasta nivel de género, siendo Botritis y Fusarium los que se encontraron con mayor presencia en las muestras de hojas asintomáticas y con síntomas. Para las muestras de suelo, el género más frecuente fue Penicillium. Conclusiones. De los tres medios evaluados, el agar extracto Sabouraud mostró los mejores resultados para el crecimiento de la mayoría de los hongos. Se establecieron mecanismos de transmisión probables para cada uno de los hongos encontrados en asociación a B. Oleracea var. capitata y se estableció que Botrytis sp. es el posible agente patógeno causante de la sintomatología observada en las muestras.

Introduction. Phytopathogenic fungi represent the main economic losses worldwide in different types of crops, including vegetables such as Brassica Oleracea var. capitata. Objectives. Identify the possible phytopathogenic fungi associated with Brassica, the signs and symptoms they may cause, their possible transmission mechanism, and to qualitatively compare their growth in different culture media. Materials and methods. Leaves with and without symptoms were isolated, together with soil samples to elaborate serial dilutions. As for microscopy, the reproductive parts of the fungi were visualized for taxonomic classification. Results. A total of 17 morphotypes were isolated up to genus level, being Botrytis and Fusarium, the genera found with the highest presence in asymptomatic and symptomatic leaf samples. For soil samples, the most frequent genus was Penicillium. Conclusions. Of the three media evaluated, Sabouraud's extract agar showed the best results for the growth of most fungi. Probable transmission mechanisms were established for each of the fungi found in association with B. oleracea var. capitata and Botrytis sp. was established as the possible pathogen causing the symptoms observed in the samples.

Control of pest ants by pathogenic fungi: state of the art.

Pest ants are known for their damage to biodiversity, harm to agriculture, and negative impact on human welfare. Ants thrive when environmental opportunities arise, becoming pests and/or invading non-native areas. As social insects, they are extremely difficult to control using sustainable methods like biological control. The latter, although safer to the environment, acts slowly allowing the ants to use their individual and social defenses. Among biocontrol agents, fungal pathogens were proposed as promising, however, it is difficult to ascertain their success when the bibliography has not been reviewed and condensed. Therefore, this paper is the first in performing such task by analyzing publications mainly from 2000 to 2022 about the control of pest ants by fungi. From 85 publications selected, 77% corresponded to laboratory studies. Beauveria and Metarhizium were the genera most used in laboratory and field studies. Most of them included Acromyrmex and Atta leaf-cutter ants (LCA), and Solenopsis fire ants. From laboratory experiments, we evaluated how ant net mortality was affected by ant and fungal species, and also by origin, concentration, and inoculation technique of the fungal strains tested. Beauveria bassiana and Metarhizium anisopliae produced the greatest mortality, along with the inoculation spray technique and fungal strains collected from ants. There was a positive relationship between ant mortality and fungal concentration only for those studies which evaluated more than one concentration. Twenty field experimental studies were found, covering 13 pest species, mainly LCA and Solenopsis invicta. Only B. bassiana was tested on Solenopsis, M. anisopliae was mostly used for Acromyrmex, and M. anisopliae or Trichoderma were mainly used with Atta species. The median control field efficiency varied from 20% to 85% for different fungi and ant genera. When grouping all fungal species together, the median control efficiency seemed to be better for Acromyrmex (67%) than for Atta and Solenopsis (both 43%). Our review shows that, at this stage of knowledge, it is very difficult to extrapolate any result. We offer suggestions to improve and standardize laboratory and field experimental studies in order to advance more efficiently in the fungal control of pest ants.