Detection and Identification of Phytophthora Species in Southern Italy by RFLP and Sequence Analysis of PCR-amplified Nuclear Ribosomal DNA

• Published in: European journal of plant pathology Vol. 113; no. 1; pp. 1 - 14
• Main Authors: Camele, I, Marcone, C, Cristinzio, G
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01.09.2005; Springer Nature B.V
• Subjects: Bacteria; Biological and medical sciences; blight; disease detection; Fragaria; Fundamental and applied biological sciences. Psychology; fungal diseases of plants; Fungal plant pathogens; host plants; host range; Lycopersicon esculentum; Microbiology; molecular sequence data; new geographic records; nucleotide sequences; pathogen identification; Phytopathology. Animal pests. Plant and forest protection; Phytophthora; Phytophthora capsici; Plant diseases; plant pathogenic fungi; polymerase chain reaction; restriction fragment length polymorphism; Ribosomal DNA; Tentaculata; Tomatoes; Vegetables; Italy; Calabria; Basilicata; Apulia; Campania; Europe; Small fruits; Repeated sequence; ITS regions; Citrus fruit; Phycomycetes; Rosaceae; Rutaceae; Ribosomal DNA; Identification; Fungi; phylogenetic analysis; Dicotyledones; Angiospermae; Lycopersicon esculentum; Solanaceae; Thallophyta; Citrus clementina; fungal-like organism taxonomy; Fragaria; Phytophthora diseases; Root; Nucleotide sequence; DNA-based methods; Polymerase chain reaction; restriction endonucleases; Vegetable crop; Herbaceous plant; Spermatophyta; Detection; Phytophthora capsici
• ISSN: 0929-1873; 1573-8469
• DOI: 10.1007/s10658-005-8915-1

In four neighbouring regions of southern Italy, Basilicata, Campania, Apulia and Calabria, pepper and zucchini plants showing Phytophthora blight symptoms, tomato plants with either late blight or buckeye rot symptoms, plants of strawberry showing crown rot symptoms and declining clementine trees with root and fruit rot were examined for Phytophthora infections by means of polymerase chain reaction (PCR) assays, using primers directed to nuclear ribosomal DNA (rDNA) repeat sequences. All diseased plants and trees examined tested positive. The detected fungal-like organisms were differentiated and characterized on the basis of primer specificity as well as through extensive restriction fragment length polymorphism (RFLP) and sequence analysis of PCR-amplified rDNA. Phytophthora capsici was identified in diseased pepper and zucchini plants, P. infestans was identified in tomato with late blight symptoms whereas buckeye rot-affected tomatoes and diseased strawberry plants proved to be infected by P. nicotianae and P. cactorum, respectively. Declining clementine trees were infected with P. citrophthora and P. nicotianae in about the same proportion. Also, thirty-one pure culture-maintained isolates of Phytophthora which had previously been identified in southern Italy by traditional methods but were never examined molecularly, were examined by RFLP and sequence analysis of PCR-amplified nuclear rDNA. Among these, an isolate from gerbera which had previously been identified by traditional methods only at genus level, was assigned to P. tentaculata. For the remaining pure culture-maintained isolates examined, the molecular identification data obtained corresponded with those delineated by traditional methods. Most of the diseases examined were already known to occur in southern Italy but the pathogens were molecularly detected and fully characterized at nuclear rDNA repeat level only from other geographic areas, very often outside Italy. A new disease to southern Italy was the Phytophthora blight of zucchini. This is also the first report on the presence and molecular identification of P. tentaculata from Italy.