FIGURA 8- - uploaded by Maria Alves Ferreira
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A) Árvore infectada por Ceratocystis fimbriata em áreas de rebrota, B) Presença de cupins e morte em plantas infectada com C. fimbriata, C) Tronco infectado colonizado por cupins e D) Presença de galerias feitas por coleobrocas.
Citations
... In Brazil, only three species of Ceratocystis are found: C. paradoxa, which infects mainly monocots (SANTOS et al. 2017); C. cacaofunesta, which causes losses in cacao plantations (SILVA et al. 2007); and C. fimbriata, which attacks many woody plants (FERREIRA et al. 2013). Therefore, more indepth morphological studies, including macroscopic and microscopic characteristics, are essential tools in the taxonomic studies of Ceratocystis in yerba mate. ...
... For each fungal structure, 100 repetitions were performed. Data of the morphological characterization of the 11 isolates were compared with the results of the morphological characterization of isolates of C. fimbriata from rubber tree (VALDETARO, 2012), eucalyptus (FERREIRA et al. 2013) and kiwi (PIVETA, 2013). ...
... There was no mycelial growth below 8 ºC and above 36 ºC. The isolates of C. fimbriata from yerba mate showed superficial or submerged in the substrate perithecia, with color ranging from brown to black both at the base and neck of the perithecium, similar to the results in rubbertree (VALDETARO, 2012), in eucalyptus (FERREIRA et al. 2013) and kiwi (PIVETA, 2013). However, there were greater dimensions for length and width of the ascomatal base and neck of the perithecium; results that approach the values found in eucalyptus (FIRMINO, 2011). ...
This study aimed to morphologically characterize the isolates of Ceratocystis fimbriata from yerba mate and to evaluate the effect of culture medium and temperature on mycelial growth and sporulation of C. fimbriata. For the morphological characterization of the 11 monosporic isolates of the fungus, slides were prepared to determine the dimensions of the sexual and asexual structures of the fungus. Four experiments were conducted to evaluate the mycelial growth and to evaluate the sporulation of C. fimbriata in different culture mediums and temperatures. The isolates of C. fimbriata from yerba mate showed perithecia with brown to black necks, divergent ostiolar hyphae, hatshaped hyaline ascospores, single-celled, cylindrical endoconidia, and globular to ovoid aleurioconidia. PDA and V8-agar media showed the highest mycelial growth. The average optimum temperature for mycelial growth and sporulation of isolates of C. fimbriata of yerba mate were 22.5 and 22.4 ºC, respectively.
Tectona grandis L.f. es una especie forestal de madera dura, que a pesar de no ser nativa de América, su plasticidad de adaptación ha permitido que en Ecuador se establezcan plantaciones intensivas con fines de exportación. Una compleja enfermedad con características de marchitez vascular está matando miles de árboles de diferentes edades en el país. Se planteó conocer el agente fitopatógeno causante de la patogénesis y muerte de los árboles. Se aislaron los hongos Fusarium sp. y Ceratocystis fimbriata Ellis & Halst. desde árboles enfermos. A nivel de invernadero se plantearon los postulados de Koch, para el efecto 30 plantas de T. grandis de cuatro meses de edad por cada tratamiento, se inocularon con los microrganismos como se describe a continuación: T1= C. fimbriata, T2 = Fusarium sp., T3 = C. fimbriata + Fusarium sp., T4 = agar-agar (control). Se empleó un diseño completo al azar (DCA) y las plantas se evaluaron a los 45 días después de inoculadas. Los tratamientos C. fimbriata, y C. fimbriata + Fusarium sp., mostraron mayores volúmenes aparentes de necrosis, con 1.52 cm3 y 1.93 cm3, y plantas muertas por la infección durante el tiempo de evaluación, mientras que Fusarium sp. mostró baja o nula patogenicidad y comportamiento similar al control, con 0.27 cm3 y 0.16 cm3 respectivamente. Estos resultados sugieren que el agente causal de la enfermedad de marchitez vascular en T. grandis es C. fimbriata y sería el primer reporte del fitopatógeno atacando teca en Ecuador.
In Brazil, the selection and planting of eucalyptus clones resistant to Ceratocystis fimbriata is the pre-eminent control strategy for the wilt pathogen. However, little is known about host defence responses associated with resistance of eucalyptus to C. fimbriata infection. In this work, enzymatic activity, sugars, lignin, total phenols and phenolic compounds involved in the defence response of eucalyptus clones resistant (RC) and susceptible (SC) to the Ceratocystis wilt were evaluated. Changes were detected in the sugars produced by RC clones, with higher concentrations occurring compared with SC. A similar response occurred with lignin content at 28 days after inoculation (dai) in RC plants. SC plants had an increase in polyphenol oxidase and peroxidase activities at 7 dai. In contrast, RC plants demonstrated high activity of the same enzymes at 2 and 4 dai, decreasing afterwards. There was no difference in phenylalanine ammonia-lyase activity between resistant and susceptible clones. Hydroxycinnamic acid concentration was higher in RC than in SC; however, there was no difference between RC and SC in flavonoid concentrations. RC had high concentrations catechin, chlorogenic acid and caffeic acid. Histochemical tests demonstrated the presence of phenolic compounds and lignin, at higher intensities, in xylem of RC plants. Inoculation with C. fimbriata induced defence responses in both resistant and susceptible eucalyptus clones, but both the intensity and speed of the responses were higher in RC. Alterations in the concentrations of sugars and lignin, as well as certain enzymes and phenolic compounds, could be used to predict the relative susceptibilities to Ceratocystis wilt of different phenotypes of eucalyptus clones.
