Chrysoporthe cubensis emerges causing wilt on Eucalyptus mini-stumps in Brazil

• Published in: Australasian plant pathology 2023-09, Vol.52 (5), p.517-527
• Main Authors: Martins, Mateus Durso, Guterres, Débora Cervieri, Andrade, Priscila Raiane Assunção, Machado, Franklin Jackson, Furtado, Gleiber Quintão
• Format: Article
• Language: English
• Subjects: Actin; Agriculture; Biomedical and Life Sciences; Chrysoporthe cubensis; Cloning; Ecology; Entomology; Eucalyptus; High temperature; Life Sciences; Original Research Article; Pathogenicity; Pathogens; Phylogeny; Plant Pathology; Plant Sciences; Signs and symptoms; Temperature effects; Tubulin; Wilt; Xylem
• ISSN: 0815-3191; 1448-6032
• DOI: 10.1007/s13313-023-00940-w

A fungus that resembles Chrysoporthe sp. was found associated with Eucalyptus mini-stumps in clonal mini-gardens in Brazil causing severe losses. The symptoms observed were wilt that evolves into partial or complete drying and death of the canopy, and lesion in the xylem of the mini-stumps. The primary objectives of this research were (i) to determine the causal agent of the wilt disease using morphological and molecular analyses; (ii) to assess the pathogenicity of the isolates on various commercial clones of Eucalyptus ; and (iii) to evaluate the impact of temperature on the pathogen’s development. Through phylogenetic analyses of sequences from the Internal Transcribed Spacer, actin, and β-tubulin genes, Chrysoporthe cubensis was identified as the causal agent responsible for the wilt disease. All six tested Eucalyptus clones exhibited susceptibility to the pathogen, with clone CNB 007 demonstrating higher susceptibility and clones CNB 005 and CNB 030 displaying comparatively lower susceptibility. Furthermore, the development of the isolates varied depending on the Eucalyptus clone, with higher temperatures favouring pathogen growth. Notably, the less susceptible clones exhibited greater sensitivity to elevated temperatures compared to the more susceptible ones. This study represents the first report of C. cubensis causing wilt disease on Eucalyptus mini-stumps worldwide.