Saturday, 19 January 2013

A touch of the exotic

When you hear the word ‘virus’ at this time of year, you think of ’flu and other nasty infections.

One doesn’t associate orchids with viruses, but they do get them. However, many are ‘symptomless’ – surely the best kind.

Australian scientists investigating indigenous and exotic viruses in orchids have identified a virus never before found in orchids.

Researchers from Murdoch University and the Botanic Gardens and Parks Authority tested four species of donkey orchids (Diuris) for RNA viruses.

They tested two wild populations of donkey orchids and two captive populations including one at Kings Park and one in South Australia and found 11 isolates of eight distinct viruses.

According to Murdoch University’s WA State Agricultural Biotechnology Centre senior research fellow Steve Wylie: ‘Nobody has looked seriously at Western Australian indigenous plants for the viruses that infect them or what sort of implications they might have for the plants.’

A report says they are concerned that exotic viruses, ones brought into the country, might spread to native flora. Meanwhile, other viruses must have evolved long before anybody came here.

The team tested four orchid species with a technique called Next Generation Sequencing because of the plants’ wide distribution in wild and captive populations.

They found exotic viruses are infecting both the captive populations and the wild populations. One rare orchid (diuris pendunculata) was co-infected with four different viruses but was otherwise healthy.

One of the four viruses (Turnip yellows virus) had never been found in orchids before and is prevalent in canola, cabbages and turnips.

Everything they tested had at least one virus and surmised that in the wild most plants are infected yet live quite happily. The next job is to see if indigenous viruses are possibly even beneficial, or if introduced viruses have a negative effect such as reducing lifespan and then, seeing if it would it be worthwhile getting rid of the viruses to safeguard stock.