ISHS Acta Horticulturae 695: I International Symposium on Tomato Diseases
DETECTION AND CHARACTERIZATION OF PHYTOPHTHORA SPECIES INFECTING TOMATO IN SOUTHERN ITALY BY DNA-BASED METHODS |
| Authors: | I. Camele, C. Marcone, G.L. Rana |
| Keywords: | PCR, RFLP, ribosomal DNA, internal transcribed spacer, late blight, buckeye rot |
| Abstract:
During summer and autumn 2002, in three regions of southern Italy, Apulia, Basilicata and Campania, where tomato is an economically important crop, unusual cool and wet weather conditions, very favorable to diseases caused by Phytophthora species occurred. Consequently, severe late blight, buckeye rot and/or stem and root rot symptoms on tomato were observed in several tomato growing areas of the above mentioned regions. In order to test the Phytophthora etiology of the tomato diseases occurring in southern Italy, symptomatic plants were examined by polymerase chain reaction (PCR) assays using universal fungal primers and primers specific for Phytophthora species. The primers used were directed to nuclear ribosomal DNA (rDNA) sequences. All symptomatic plants tested positive. The detected fungi were differentiated and characterized on the basis of primer specificity and extensive restriction fragment length polymorphism (RFLP) and sequence analyses of PCR-amplified rDNA. P. infestans was identified in tomatoes with late blight symptoms, whereas buckeye rot-affected tomato plants proved to be infected by P. nicotianae. No polymorphism among isolates of each Phytophthora species identified was observed by RFLP analysis. The diseases examined were known in southern Italy, but the pathogens were molecularly detected and characterized only from other geographic areas outside Italy. Thus, this is the first report from Italy on molecular detection and identification of Phytophthora species infecting tomato using nuclear rDNA markers. | |
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