Molecular diagnostic tools for the detection and characterization of Phoma tracheiphila

In the recent years PCR-based techniques for the identification and detection of Phoma tracheiphila, the causal agent of citrus mal secco disease, have been evaluated aiming to provide tools for biological and epidemiological studies. A wide collection of P. tracheiphila strains was used to evaluate and validate diagnostic protocols and a fAFLP method for fungal characterization. Conventional and real-time PCR protocols were successfully tested for the specific identification of P. tracheiphila and its detection in planta. A further improvement of the real-time PCR protocol and the DNA extraction methods allowed the quantification of the fungus both from naturally infected and artificially …

Identification and Detection of Phoma tracheiphila, Causal Agent of Citrus Mal Secco Disease, by Real-Time Polymerase Chain Reaction.

Phoma tracheiphila is the causal agent of a tracheomycotic disease of citrus called mal secco causing the dieback of twigs and branches. This pathogen is of quarantine concern; therefore, fast and reliable protocols are required to detect it promptly. A specific primer pair and a dual-labeled fluorogenic probe were used in a real-time polymerase chain reaction (PCR) with the Cepheid Smart Cycler II System (Transportable Device TD configuration) to detect this fungus in citrus samples. Real-time PCR assay was compared to modified conventional PCR assay. The sensitivity of the former was evaluated by testing P. tracheiphila DNA dilutions, and the minimum amount detectable was about 500 fg, wh…

First Report of Armillaria Butt Rot Caused by Armillaria mellea on Phoenix canariensis in Italy.

During 2006, in a garden in the Mount Etna Piedmont, eastern Sicily (Italy), a 40-year-old specimen of Canary Island date palm (Phoenix canariensis hort. ex Chabaud) with a trunk circumference at breast height of 220 cm showed a rotted lesion with a viscous, brown ooze at the stem base and root initials. The lesion extended to approximately one-third of the trunk circumference. Trunk excavation exposed a wet rot of internal tissues, a cream-colored mycelial mat, and a mushroom-like smell. Although the rot spread inward (approximately 25 cm deep) with decay of nonlignified ground tissues and blackening of wood fibers, the palm did not show symptoms on the canopy. Conversely, ferns, apricot,…

Phytophthora species on ornamental plants in Italy