The new deal in virus discovery: a major concern for "minor" crops.

The use of NGS approach allowed the identification and the complete genome characterization of several plant virus species, previously unknown (Persimmon cryptic virus, PeCV; Mulberry badnavirus-1, MBV-1), or scarcely characterized and never associated to a specific symptomatology and/or host (Persimmon rhabdovirus A, PeVA; Apple green crinkle associated virus, AGCaV). Significantly these findings arose from crops, respectively Japanese persimmon (Diospyros kaki) in the case of PeCV and PeVA, quince (Cydonia oblonga) for AGCV and mulberry (Morus alba) for MBV-1, disregarded in traditional quest for viral agents and diseases. Routinely used bio- and molecular assays, however modern they are, always hide an a priori choice for target, influenced by evident symptomatology, diagnostic purposes prone to certification standard enquiries, availability of literature, etc. NGS analysis, being apart from such constraints, gives the opportunity to widen the target range, thus including also cultivated and wild crops, so far considered not agronomically relevant, or never characterized for their sanitary status. The new approach, accounting on a better feasibility and reliability of detection performance, is leading to noteworthy steps forward for plant virology studies addressed to characterize minor crop infections. A rising number of new species discovered, in once misinvestigated temperate and tropical fruit crops, should not be merely regarded in terms of basic research accomplishments. The meaningful contribution of NGS advent in this field, relies in a potential of innovative knowledge to be expended, for instance, in upgrading the extant certification schemes, tracking unforeseen threats in propagative material exchanges and setting new attribution rules for a challenging taxonomical allocation of oncoming species or strains.