Abstract
Interactions between the fungal symbionts of the polyphagous shot hole borer (PSHB) Euwallacea nr. fornicatus and avocado host trees of cultivars ‘Hass’ and ‘Ettinger’ were studied, with emphasis on the three symbiotic fungi of the beetle. Fusarium euwallaceae did not spread far from the beetle galleries and remained viable in live xylem for 25 months; Graphium euwallaceae and Paracremonium pembeum disappeared from the live tissue 2 months after inoculation, but remained viable in dead xylem. The role of F. euwallaceae as a pathogen that contributes to typical wilting symptoms of PSHB-colonized avocado branches was assessed. The enhanced resistance of ‘Ettinger’ than of ‘Hass’ as manifested in its fewer beetle attacks was not reflected in the interaction of these cultivars with the symbiotic fungi. The specific pseudo-pathogenic interaction of F. euwallaceae with the xylem may be the key to understanding the different susceptibility between attacked hosts.
Original language | English |
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Pages (from-to) | 117-130 |
Number of pages | 14 |
Journal | Fungal Ecology |
Volume | 39 |
DOIs | |
State | Published - Jun 2019 |
Externally published | Yes |
Bibliographical note
Funding Information:The authors are grateful to Dr. Hillary Voet, from the Robert H. Smith Faculty of Agriculture, Food and Environment at The Hebrew University of Jerusalem, for assistance with statistical analysis of the data. The authors thank Dr. Matt Kasson, Virginia Tech University, Blacksburg, VA, USA and Dr. K. O'Donnell, USDA-ARS, Peoria, IL, USA for their valuable comments, while previewing this manuscript before submission. We also thank the two anonymous reviewers for their important suggestions. We express our appreciation to Dr. Jonathan Maoz, of the Avocado Organization, Israeli Plants Board for sampling data, and to the many avocado growers, gardeners and landscape managers who shared valuable information regarding infested hosts on their properties and allowed us to remove plant materials for the present study. This research was partially funded by grants from the Chief Scientist of the Israeli Ministry of Agriculture and Rural Development (Nos. 131-1679 and 131-1834 ), and from the Israeli Avocado Growers' Association.
Publisher Copyright:
© 2018 Elsevier Ltd and British Mycological Society
Keywords
- Ambrosia beetle
- Avocado Fusarium
- Euwallacea
- Graphium
- Symbiotic fungi