Latent potyvirus infections in Crocus sativus cartwrightianus: an underestimated problem in saffron?

Abstract

In over two decades, while studying saffron reproductive biology, we frequently found ultrastructural alterations typical of potyvirus infection in stigmas, styles and leaves of Crocus sativus (saffron) and C. cartwrightianus (wild and ornamental species, a putative ancestor of saffron) from different provenance. This suggests that these viruses are widely diffused in cultivated Crocus spp., possibly causing latent infections. The few data found in literature, while highlighting the general lack of attention given by plant virologists to Crocus spp., nevertheless confi rm that potyviruses, particularly Bean yellow mosaic virus (BYMV), can cause asymptomatic infections in these host species. The reasons and possible implications of widely distributed potyvirus latent infections in Crocus spp. are reported and discussed, with the aim of increasing general awareness of these viruses, and of encouraging sanitary selection programs focused on saffron, that could improve the quantity and quality of yields of the most expensive spice commodity grown.