Diplodia corticola and Phytophthora cinnamomi: the main pathogens involved in holm oak decline on Caprera Island (Italy). Issue 3 (4th December 2013)

• Record Type: Journal Article
• Authors: Linaldeddu, B. T.; Scanu, B.; Maddau, L.; Franceschini, A.; Belbahri, L.
• Is Part Of: Forest pathology. Volume 44:Issue 3(2014:Jun.)
• Page Start: 191
• Page End: 200
• Publication Date: 2013-12-04
• Subjects: Trees -- Diseases and pests -- Periodicals; Trees -- Effect of air pollution on -- Periodicals; Forests and forestry -- Environmental aspects -- Periodicals; 634.9
• DOI: 10.1111/efp.12081
• Languages: English
• ISSNs: 1437-4781

Abstract

<abstract abstract-type="main" id="efp12081-abs-0001"> <title>Summary</title> <p>Since 2008, severe and widespread tree decline and mortality has been observed at the main growing <italic>Quercus ilex</italic> L. (holm oak) forest on Caprera Island, Italy. To clarify the symptomatology and aetiology of this phenomenon, field surveys and isolations from symptomatic trees were carried out in summer 2010. Affected trees exhibited crown thinning, branch dieback, sunken cankers, epicormic shoots, exudates on branches and trunk, root losses and sudden death symptoms. Four fungal species belonging to <italic>Botryosphaeriaceae</italic> family, namely <italic>Botryosphaeria dothidea</italic>, <italic> Diplodia corticola</italic>, <italic> D. seriata</italic> and <italic>Neofusicoccum parvum</italic>, were isolated from cankers on trunk and branches, whereas three species of <italic>Phytophthora</italic>, namely <italic>P. cinnamomi</italic>, <italic> P. cryptogea</italic> and <italic>P. gonapodyides</italic>, were isolated from fine roots and rhizosphere soil samples. Isolates were identified using both morphological analysis and DNA‐based techniques. Pathogenicity trials on holm oak seedlings showed that all the isolated species are pathogenic. <italic>D. corticola</italic> proved to be the most aggressive species. Our results provide the first evidence for a combined involvement of <italic>D. corticola</italic> and <italic>P. cinnamomi</italic> in the aetiology of holm oak decline in Italy and suggest that these pathogens are not only important contributing factors in the onset of long‐term tree decline, but also may cause the rapid devastation of extensive oak ecosystems.</p> </abstract>