|Riassunto in Inglese:|
Fusarium fujikuroi Nirenberg, (teleomorph: Gibberella fujikuroi Sawada) is the causal agent of Bakanae disease of rice, causing increasing losses to Italian production in the last years. The aim of this study is to understand the genetic structure of Italian F. fujikuroi populations identifying genetic and genotypic diversity by developing microsatellite molecular markers.
A collection of about 240 isolates of F. fujikuroi was established starting from the infected culms of plants showing the typical Bakanae symptoms, collected during 2011 from cultivated fields in different Italian regions. Morphological and molecular analysis allowed to identify F. fujikuroi as the major responsible for the disease. All the available nucleotidic sequences of F. fujikuroi, published in NCBI database, were used to find microsatellite motifs (SSRs) through a microsatellite finder software (WebSat; http://wsmartins.net/websat/). Perfect mono-, di-, tri-, tetra-, penta-, and hexa-nucleotide motifs with a repeat of ? 6 times were identified. The longest microsatellite repeats were selected and were amplified with primers designed by the primer3 software. Moreover, some of the SSRs used for Fusarium verticillioides and available from literature, are going to be tested for their capacity in identifying polymorphisms in F. fujikuroi, taking into account that both these species belong to Gibberella fujikuroi complex. The length polymorphisms were detected by Polyacrilamide Gel Electrophoresis (PAGE) and analysed by statistical tools. The genetic variation of pathogen populations opens up new challenges for rice breeders in developing Bakanae-resistant rice varieties. Understanding the genetic structure of F. fujikuroi may facilitate to understand its biology and evolution and can be useful to improve the disease management.