Survey on the phytosanitary conditions of rice reproduction seeds in northern Italy

Among the European countries Italy, is the major producer and exporter of rice reproduction seeds. In 2003, 50.917,23 tons of rice reproduction seeds were certified and 10.057,83 tons were exported. The sanitary state of the kernels was carefully examined, because of the importance of the colture and the necessity to have high qualitative seed standards. Pyricularia oryzae, Bipolaris oryzae, Alternaria spp. and Fusarium moniliforme were the mesi frequently isolated fungal species. Since in these last years the infection on cereal grains by Fusarium spp. has increased, it has been investigated if this pathogen was present on rice production seeds. The survey carried out during 2003 had the aim to verify the sanitary state of rice seeds especially far the presence of Fusarium species. Three main regions of Northern Italy were taken into consideration: Piemonte with the districts of Alessandria, Biella, Cuneo and Novara, Lombardia with the districts of Lodi, Milano and Pavia and finally Venale with the district of Verona. Hundred and three samples of rice seeds with husks, approximately 1.0 kg far each sample, from farms that produce rice reproduction seeds, were collected and were subjected to laboratory analysis. The seeds were òisinfested with NaOCI, placed on the surface of PDA medium added with antibiotics and incubated at 21°C :!: 1°C under alternate cycles of 12 h NUV light and 12 h of darkness far 7 days. The fungal colonies which, far their morpholgy, resembled Fusarium species, were reisolated with a Single Spara method, plated on PDA medium, then identified under optical microscope and/or using qualitative Polymerase Chain Reaction (PCR). Eighty samples were infested with Fusarium spp.. In the district of Biella, Cuneo, Lodi and Milano ali the samples were infested with Fusarium while in Alessandria, Novara, Vercelli, Pavia and Verona the sample infestation was respectively of 71.4%, 78.3%, 64.0%, 80.8% and 84.6%. The infestation levai of the seeds was instead very low: in fact the highest value was found in the samples of Lodi district, with an average of 5.4% of infested seeds. F. semitectum was the mesi frequent Fusarium found with an average of 47% reaching peaks of 71 % in the district of Pavia. F. moniliforme complex (F. proliferatum, F. verticelloides and F. subglutinans), F. graminearum, F. oxysporum and F. equiseti were also isolated from rice reproduction seeds. Alternaria spp., Bipolaris sp., Nigrospora sp., Curvularia sp., Sordaria sp., Cladosporium sp., Aspergillus sp., besides the species of Fusarium, were also detected. The data obtained during the 2004 survey partially coFlfirm the 2003 results