Seed-borne fungi: challenges in seed health testing for biosecurity and agricultural sustainability

Seed is one of the key inputs which play an important role in ensuring long-term conservation of crops for sustainability. On the other hand, infected seeds, a threatening biosecurity concern, is a mean of perpetuation/ survival and long-distance movement of fungal pathogens breaking geographical barrier. Large number of fungal plant pathogens belonging to as many as ~ 1500 species are known to be seed-borne/ seed-transmitted in more than 500 crop species of economic importance, which cause not only significant yield losses, but also deteriorate the seed quality drastically. As a result of international exchange of crop seeds, several seed-borne fungi have been proven detrimental leading to severe epidemics in the past. To ensure agricultural sustainability and biosecurity in future, this review presents the implication of testing seed-borne fungal pathogens for healthy long-term conservation as well as safe international exchange of plant genetic resources including crop wild relatives, and strategies to combat those implications.