Phytopathological Threats Associated with Quinoa ( Willd.) Cultivation and Seed Production in an Area of Central Italy.

In 2017, in a new cultivation area (Central Italy), emergence failures of the Titicaca, Rio Bamba, and Real varieties, whose seeds were obtained the previous year (2016) in the same location, were observed. Moreover, leaf disease symptoms on the Regalona variety, whose seeds came from Chile, were detected. Visual and microscopic analyses showed the presence of browning/necrotic symptoms on the seeds of the three varieties whose emergence in the field had failed. In addition, their in vitro germination rates were strongly compromised. spp. was isolated with high incidence from Titicaca, Rio Bamba, and Real seeds. Among the detected species, in the phylogenetic analysis, the dominant one clustered in the sub-clade of the (FIESC) species complex. Instead, the pathogen associated with Regalona leaf symptoms was identified, by morphological and molecular features, as , the causal agents of downy mildew. This is the first report of both and on in Italy. Species-specific primers also detected in Regalona seeds. These results underline the importance of pathogen monitoring in new quinoa distribution areas, as well as of healthy seed production and import for successful cultivation.