Mycopathologia (2005) 159, 591-599

Mariarosaria Vergara, Tiziana Capasso, Emanuela Gobbi and Giovanni Vannacci (2005)
Plasmid distribution in European Diaporthe helianthi isolates
Mycopathologia 159 (4), 591-599
Abstract: Diaporthe helianthi is the causal agent of sunflower stem canker, a serious pathogen of sunflower in Europe, which has been sporadically recorded in Italy. A collection of 26 Diaporthe helianthi isolates deriving from different geographic origins was analysed in order to determine the presence of extra-chromosomal genetic determinants and their molecular diversity. Extra-chromosomal bands in total genomic DNAs were identified in every French and the Yugoslavian isolate and in only one Italian isolate, while no Romanian and Argentinean isolates resulted to host any plasmids. When tested for their chemicophysical nature, they were recognised as linear plasmids sized about 2.3 Kb. A more detailed analysis was performed on a plasmid purified from a French isolate (plasmid F). Its intracellular localisation resulted as mitochondrial. Plasmid F was also exploited as a probe in Southern hybridisation experiments, in which it recognised only plasmids present in the genomes of French and Yugoslavian isolates (countries were the disease has a heavy incidence) indicating a strong correlation to geographic origin. An RFLP hybridisation analysis performed on genomic DNAs revealed a homogeneous restriction pattern in all French and Yugoslavian isolates, suggesting molecular homology among plasmids present in those isolates.
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Link to article at publishers website
Database assignments for author(s): Mariarosaria Vergara, Giovanni Vannacci, Emanuela Gobbi

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

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Diaporthe helianthi		France
	Diaporthe helianthi		Italy
	Diaporthe helianthi		Romania
	Diaporthe helianthi		Serbia
	Diaporthe helianthi		Argentina