Journal of Plant Pathology (2004) 86, 300-301

C. Moretti, F.M. Silvestri, E. Rossini, G. Natalini and R. Buonaurio (2004)
Diagnostic tools for the identification of Brenneria nigrifluens, the causal agent of Persian walnut bark canker
Journal of Plant Pathology 86 (4), 300-301
XI Meeting, Italian Society for Plant Pathology, Milan, 29/9 - 1/10, 2004
Abstract: After the first report from northern Italy (Veneto and Piemonte) in 1998, bark canker of Persian walnut (Juglans regia L.), caused by Brenneria nigrifluens, was recorded again from other Italian regions (Lazio and Campania). In 2002, we observed the disease in walnut plantations for timber production in 13 farms of central Italy (Umbria and Marche). The totality of 44 bacterial isolates from symptomatic plants were Gram-negative and had oxidative and fermentative metabolism. Twenty of them were submitted to API 20E system (bioMérieux) for identification because they were oxidase negative and therefore belonged to the Enterobacteriaceae. Four isolates (one from Umbria and three from Marche) gave the 7-digit code 0005773, which is identical to that reported for the type strain LMG 2694^T and the two reference strains LMG 5107 and LMG 5953 of B. nigrifluens. When trunks of young walnut plants were inoculated with these four isolates, typical symptoms of the disease developed three months after inoculation. A number of isolates associated with bark cankers, which were not pathogenic to walnut, were identified as Erwinia rhapontici using the API 20E system. Rep-PCR using primers REP showed that pathogenic isolates had high similarity (89%) with the type and reference strains of B. nigrifluens. The development is in progress of a molecular assay exploiting a 905 by fragment amplified during REP-PCR, which seems to be characteristic for B. nigrifluens.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Roberto Buonaurio, Chiaraluce Moretti

Research topic(s) for pests/diseases/weeds:
identification/taxonomy
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Brenneria nigrifluens	Walnut/butternut (Juglans)	Italy