MOLECULAR ANALYSIS OF COLLETOTRICHUM SPECIES ASSOCIATED TO OLIVE IN CALABRIA.

A new molecular approach based on the use of genus-specific primers targeting the internal transcribed spacer (ITS) regions of rDNA, was developed and used to study the diversity of Colletotrichum species associated with the olive canopy in the Gioia Tauro plain (Calabria, southern Italy). Representative symptomatic and symptomless samples of leaves, flowers and fruits were collected during 2012 and analyzed by extracting total DNA and amplifying the target region with the genus-specific primers. Amplicons were cloned and sequenced in order to use the ITS as a barcode gene. No Colletotrichum species were detected in the first sampling period (May 28, 2012), whereas around 15% of the analyze…

MOLECULAR ANALYSIS OF PHYTOPHTHORA DIVERSITY IN ORNAMENTAL NURSERIES.

A molecular approach based on the use of genus-specific nested-PCR primers (Scibetta et al., 2012; J. Microbiol. Meth. 88: 356-368) was utilized to detect Phytophthora species in soil and root samples of potted ornamentals, collected across Apulia and Calabria, Southern Italy. Analyzed samples comprised many plant species with different levels of symptoms of decline on the canopy and root rots. Extraction protocols were optimized to obtain DNA samples of appropriate quality from soil and roots. The analysis of sequences after cloning of nested-PCR amplicons enabled the identification of different Phytophthora species including P. nicotianae, P. cinnamomi, P. cryptogea, P. palmivora and P. n…

A Metabarcoding Survey on the Fungal Microbiota Associated to the Olive Fruit Fly.

The occurrence of interaction between insects and fungi is interesting from an ecological point of view, particularly when these interactions involve insect pests and plant pathogens within an agroecosystem. In this study, we aimed to perform an accurate analysis on the fungal microbiota associated to Bactrocera oleae (Rossi) through a metabarcoding approach based on 454 pyrosequencing. From this analysis, we retrieved 43,549 reads that clustered into 128 operational taxonomic units (OTUs), of which 29 resulted in the “core” associate fungi of B. oleae. This fungal community was mainly represented by sooty mould fungi, such as Cladosporium spp., Alternaria spp. and Aureobasidium spp., by pl…

Molecular analysis ofPhytophthoradiversity in nursery-grown ornamental and fruit plants

The genetic diversity of Phytophthora spp. was investigated in potted ornamental and fruit tree species. A metabarcoding approach was used, based on a semi-nested PCR with Phytophthora genus-specific primers targeting the ITS1 region of the rDNA. More than 50 ITS1 sequence types representing at least 15 distinct Phytophthora taxa were detected. Nine had ITS sequences that grouped them in defined taxonomic groups (P. nicotianae, P. citrophthora, P. meadii, P. taxon Pgchlamydo, P. cinnamomi, P. parvispora, P. cambivora, P. niederhauserii and P. lateralis) whereas three phylotypes were associated to two or more taxa (P. citricola taxon E or III; P. pseudosyringae, P. ilicis or P. nemorosa; and…

Caratterizzazione di isolati di Colletotrichum spp. agenti causali dell’antracnosi dell’olivo