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.