Next time you plant the garlic that's sprouted in your kitchen cupboard you could be contributing to the spread of exotic viruses, say researchers.
So suggests a new study published in PLOS ONE.
"Garlic can have large numbers of viruses in it and that's exactly what we found," says plant virologist Dr Steve Wylie of Murdoch University.
Garlic is particularly susceptible to plant viruses because it propagates vegetatively and does not go through a seed stage.
"The seed has got a lot of mechanisms to filter out viruses so a lot of viruses don't actually make it through the seed and it's a way of a plant cleaning itself of viruses by going through a seed stage," says Wylie.
"Garlic doesn't have this luxury," he says. "And if you are a virus that is just a godsend."
Year after year, garlic accumulates viruses and Wylie and colleagues wondered what viruses might by hitching a ride into Australia on imported garlic.
International trade in fresh produce has been on the rise since the softening of trade barriers and the ever-popular garlic is no exception, says Wylie, adding that Australia imports 85 per cent of its garlic.
"We're bringing in 3,500 tonnes of garlic a year, mostly from China."
Wylie and colleagues went to supermarkets and collected 11 bulbs of garlic including those from Australia, China, the US, Mexico, Argentina, Spain. They then used high-throughput sequencing technology as a means of detecting viruses in the bulbs.
"Every bulb had viruses," says Wylie.
He says they found 11 RNA viruses, including species from Mexico and Argentina that were "vastly different to anything that anybody in the world had ever seen before".