Saffron (Crocus sativus L.) diseases in Italy

Surveys carried out in different Italian saffron-growing areas showed the presence of some fungal and bacterial diseases. Fusarium oxysporum f. sp. gladioli, a fungus transmitted through infected corms, was the major responsible of severe yield losses, especially in central Italy and, recently, also in Sardinia (Medio Campidano). Primary symptoms occurred during flowering. They included basal stem rot, yellowing and wilting of the shoots and corm rot. The rapid spread of the disease is caused by movement of contaminated and/or infected corms. The Italian fungus isolates from saffron did not differ by those obtained from gladiolus or saffron grown in Spain as shown by VCs groups studies. Macrophomina phaseolina was found in Sardinia. The fungus was transmitted by infected corms and caused wilting of plants and charcoal rot of corms. Penicillium spp. and Stromatinia gladioli were also found in/on the corms at the time of transplanting. Recent investigations carried out in Sardinia showed that Burkolderia sp. and Pseudomonas spp. are the causal agents of a disease characterized by rotting of the leaves, flowers and corms. Smooth and winkled colonies were isolated from plants and corms. Bacterial isolates were characterized by pathogenicity, phenotypic and PCR analysis. Most of the isolates were identified as Burkholderia gladioli and some as fluorescent pseudomonads. FLP analysis are under way to characterize the pathovar of the B. gladioli isolates. Other fungi that were recorded many years ago, such as Rhizoctonia spp. and Phoma crocophila, were not found.