Morphological and Molecular Analysis of Fusarium lateritium, the Cause of Gray Necrosis of Hazelnut Fruit in Italy.
Vitale, S.; Santori, A.; Wajnberg, E.; Castagnone-Sereno, P.; Luongo, L.; Belisario, A.
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Americal Phytopathological Society Press
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|Abstract in English:|
Fusarium lateritium is a globally distributed pathogen. It was recently reported as the agent of nut grey necrosis (NGN) on hazelnut. Morphological studies combined with inter-simple-sequence-repeat (ISSR) analysis, and sequence analysis of translation elongation factor 1-? (TEF-1?) and beta-tubulin genes as well as of nrDNA internal transcribed spacer (ITS) region were conducted to resolve relationships among 32 F. lateritium isolates from NGN affected hazelnut fruit, and 14 from other substrates or 8 from other hosts than hazelnut. Colony of F. lateritium isolates from hazelnut showed dark greyish-olive differing from the orange-yellow color of all other isolates. Generally, isolates from NGN affected fruit failed to produce sporodochia on carnation leaf agar (CLA). The influence of host and substrate on the genetic structure of F. lateritium was revealed by ISSR analysis, and a relationship between hazelnut twig cankers and NGN occurrence was inferred. Phylogenetic analysis of ITS provided limited resolution, while TEF-1? and beta-tubulin analyses allowed a clear separation between the European and non European F. lateritium isolates, retrieved from GenBank, regardless of the host. These findings suggest a potential specialization within F. lateritium complex addressed to the resolution of a F. lateritium subspecific group associated with hazelnut and/or hazelnut fruit.