Understanding soil fungi to save a genus of threatened orchids from extinction
Conservation of Leek Orchids (Prasophyllum)
There are almost 200 species of Leek Orchid (Prasophyllum spp.) in Australia, with over 40 species in New South Wales alone. They are beautiful, delicate little things, with long, slender flower spikes filled with small ‘upside-down’ flowers, often appearing the season after a fire or during wet years. But they are in trouble. Over a third of Leek Orchid species in New South Wales are endangered, some are critical - down to a handful of plants and on the very brink of extinction. The causes of their decline are all the usual suspects: land clearing, rabbits, weeds, and the situation is the same all across the country.
In this respect Leek Orchids are not unique; many of our native orchid species are struggling for survival. However, Leek Orchids face another issue: we currently do not know how to grow them in cultivation. Growing and re-introducing plants back into the wild is an essential tool in the conservation of threatened species. The Royal Botanic Gardens Victoria - Orchid Conservation Program has had great success with many endangered native orchids from southeast Australia, but we have not been able to crack the Leek Orchids. They have proven extremely difficult to grow, usually not germinating at all, or germinating but then dying soon after. Curiously though, occasionally some success has been had, but successful germination trials to our knowledge have so far proved un-repeatable.
The problem appears to be in the relationship between the Leek Orchid seed and its soil fungus. Due to the extremely small size of orchid seed, mycorrhizal fungi that live in the soil are required to inoculate and germinate the orchid seed and they also play an important role in adult plants, supplying nutrients, energy and water to the orchid. To grow native orchids from seed, we extract these fungi from the roots of an adult plant and then sow it with the seed in a petri dish in our lab. With most orchids, this works wonderfully well and the little baby orchids grow up just fine. But something is going on in the relationship between Leek Orchids and their mycorrhizal fungi that are causing seed germination and seedling growth to fail.
To try and remedy this, I am beginning a three year PhD study into Leek Orchids to work out what is going on. But, I NEED YOUR HELP! Have you ever tried to grow Leek Orchids or the related Midge Orchids (even if it was a complete failure)? Or have you ever observed them recruiting from seed in the wild? If so I would love to hear from you, please contact me at marc.freestone@rbg.vic.gov.au or 0428 304 299.
Funding and support for this project: Australian National University, Royal Botanic Gardens Victoria, Federal Government Environmental Science Programme, University of Tasmania.
Marung Leek-orchid (Prasophyllum beatrix)
restricted to a few remaining Cypress-pine blocks in the Riverina.
Sydney Group Support:
Sydney Group strongly supports all efforts aimed at conserving native orchids and requests any member who might be able to assist Marc to please get in contact with him at the earliest opportunity.
For member’s information, Marc is an Orchid Conservation Officer who works with Noushka Reiter and a dedicated group of volunteers at the Royal Botanic Gardens Victoria laboratory and nursery on their Orchid Conservation Program.
Riverina Leek-orchid (Prasophyllum aff. occidentale)
an endangered orchid from uncultivated native grasslands in the Riverina.
The Royal Botanic Gardens Victoria - Orchid Conservation Program, where Marc is studying, is the largest orchid conservation program of its type in the world. The Orchid Conservation at the Royal Botanic Gardens Victoria is entirely supported by grants and individual donations including from the Australian Orchid Foundation, The Australian Communities Foundation, The Australasian Native Orchid Society, local community groups and individuals.
Further information on the Orchid Conservation Program can be found at: https://www.rbg.vic.gov.au/science/projects/orchid-conservation
Marc is also a member of ANOS Vic and a regular radio guest on ABC Gippsland (in Victoria) where he presents a monthly segment on the flora of the Gippsland region.
Further information on Marc and his work is at the Orchid Conservation Program can be found at:
