A polyphasic approach for the characterization of endophytic Alternaria strains isolates from grapevines
Articolo
Data di Pubblicazione:
2012
Citazione:
A polyphasic approach for the characterization of endophytic Alternaria strains isolates from grapevines / R. Polizzotto, B. Andersen, M. Martini, S. Grisan, G. Assante, R. Musetti. - In: JOURNAL OF MICROBIOLOGICAL METHODS. - ISSN 0167-7012. - 88:1(2012 Jan), pp. 162-171.
Abstract:
A polyphasic approach was set up and applied to characterize 20 fungal endophytes
belonging to the genus Alternaria, recovered from grapevine in different Italian regions.
Morphological, microscopical, molecular and chemical investigations were performed and the obtained
results were combined in a pooled cluster analysis. Following morphological analyses, all strains were
grouped according to their three-dimensional sporulation pattern on PCA and to the colony
characteristics on different substrates. After DNA extraction, all strains were analyzed by RAPD-PCR
and the resulting profiles were subjected to cluster analysis. The metabolites extracted from the 20
Alternaria endophytes were analyzed by a HPLC and the resulting metabolite profiles were subjected
to multivariate statistic analyses. In comparison with reference 'small-spored' Alternaria species, the
20 strains were segregated into two morphological groups: one belonging to the A. arborescens
species-group and a second to the A. tenuissima species-group. RAPD analysis also showed that
grapevine endophytes belonged to either the A. arborescens or the A. tenuissima species-group and
that they were molecularly distinct from strains belonging to A. alternata. Chemotaxonomy gave the
same grouping: the grapevine endophytic strains belong to A. arborescens or A. tenuissima speciesgroups
producing known metabolites typical of these species-groups. Interestingly, the 20 grapevine
endophytes were able to produce also a number of unknown metabolites, whose characterization
could be useful for a more precise segregation of the two species-groups.
The results show how complementary morphological, molecular and chemical data can clarify
relationships among endophyte species-groups of low morphological divergence.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
morphology ; RAPD ; chemotaxonomy ; metabolite profiling
Elenco autori:
R. Polizzotto, B. Andersen, M. Martini, S. Grisan, G. Assante, R. Musetti
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