The genetic diversity of Phytophthora was investigated in soil and root samples ofpotted ornamental and fruit tree plants collected in nurseries located in Apulia andCalabria (Southern Italy) using metagenomic approaches based on Phytophthoragenus specific primers. PCR amplicons containing the ITS1 region of the rDNA weresequenced using both a conventional cloning and Sanger sequencing approach and a454 pyrosequencing protocol. All sequences were accurately analyzed with anappropriate software and used as barcode for species identification utilizing a validatedITS database. The cloning/Sanger sequencing approach enabled the identification ofnine different Phytophthora taxa (P. nicotianae, P. citrophthora, P. meadii, P.cinnamomi, P. parvispora, P. cambivora, P. niederhauserii, P. taxon Pgchlamido, andP. lateralis), 3 phylotypes associated to “species complexes” (P. citricola, P. cryptogeaand P. pseudosyringae) and three other phylotypes considered as unknown or non wellidentified Phytophthora taxa. The 454 pyrosequencing confirmed above results andprovided a higher levels of accuracy enabling the detection of four additional species(P. cactorum, P. psycrophila, P. palmivora and P. ramorum) and a general higher levelof diversity (number of detected genotypes) within analyzed samples. Data of thepresent study indicate the use of genus specific primers combined with next generationsequencing approaches as valuable tools to investigate Phytophthora diversity indifferent environments and pathosystems. Furthermore, the large number of genotypesand Phytophthora taxa detected in a limited geographic area confirms a primary role ofnurseries in favoring the diffusion and the evolution of Phytophthora species.
|Number of pages||1|
|Publication status||Published - 2015|