Fungi associated to bark lesions of Eucalyptus globulus stems in plantations from Uruguay

Abstract

-Trees with stem bark lesions are frequently observed in Eucalyptus globulus Labill. plantations, particularly in the central west region of Uruguay. These lesions constitute a problem for trunk decortications at harvest and they also facilitate the access of fungi that could cause wood decay. Seven, three and oneyear-old plantations, located at three sites in close proximity were selected. Four types of trunk lesions were present in trees regardless the age of plantation and more than one type was found in each plantation. The aim of this study was to investigate the fungal composition associated with these lesions and compare them to healthy tissues and try to find out the origin of these symptoms. Another purpose was to elucidate the real role of the fungi considered pathogens by means of experimental inoculations. Segments from lesions and healthy tissues yielded 897 fungal isolates belonging to 32 taxa, 681 isolates from bark lesions and 216 from healthy tissues. Both healthy and symptomatic tissues showed similar fungal species composition, but with differences in frequencies of colonization. Cytospora eucalypticola Van der Westhuizen, Botryosphaeria spp., Pestalotiopsis guepinii (Desm.) Stey. and Penicillium spp. were the dominant species isolated. As symptoms were not reproduced after experimental inoculation with Botryosphaeria ribis Grossenb. & Duggar and B. eucalyptorum Crous, & M.J. Wingf, it could be suggested that these lesions were originated by unfavorable environmental conditions. The frost that occurred for several days out of season and flooding may have been involved in the development of bark lesion.Keywords: Fungi, Botryosphaeria and Eucalyptus. FUNGOS ASOCIADOS AS LESÕES DA CASCA DO CAULE DE Eucalyptus globulus EM PLANTAÇÕES NO URUGUAI RESUMO -As lesões na casca de

A destructive new disease of Syzygium samarangense in Thailand caused by the new species Pestalotiopsis samarangensis

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Molecular, morphophysiological and pathogenic characterization of eucalypt Pestalotiopsis grandis-urophylla isolates, a new species

“…Besides, many phytosanitary problems are observed with several species in various locations and at different times of the year (Santos et al 2001). For that reason, Section Editor: Raul AllendeMolar information and research on pathogen identification and disease control are often required in order to generate knowledge on biotic problems associated to eucalypt that enable the establishment of appropriate control strategies, help reduce losses, and increase productivity in the forest sector (Alonso et al 2009;Kharwar et al 2010). Leaf spots caused by fungal pathogens have acquired great importance recently, mainly in mature eucalypt plantations (Rodas et al 2005;Lana et al 2012).…”

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A comparative study of cellulase production in inorganic and organic supplements by a cellulolytic tree bark fungus

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