Forestry Commission scientists have helped to crack a secret that might help to conserve a South American tree species that is at risk of extinction in the wild.

The Chilean plum yew (Prumnopitys andina) is an attractive conifer tree native to the Andean regions of southern Chile and Argentina. It is under threat from hydro-electric power station developments flooding its territory, and the conversion of its habitat to farmland and commercial forestry plantations. It is estimated that perhaps fewer than 10,000 plum yew trees now remain in the wild in their natural range.

And if all that were not bad enough, plum yew seeds do their species no favours in the battle for survival by being very reluctant to germinate. Previous research had indicated that germination occurs in only about 10 per cent of seeds, and this could take four years to occur. Although this rate of germination was probably enough to keep populations of the trees regenerating satisfactorily, once they are threatened by animals, flooding, fire or felling, the overall rate is too low to ensure a healthy future for the species.

Now, however, scientists in Farnham, England, working in collaboration with colleagues in Edinburgh, Scotland, have used their expertise in tree seed biology to treble the germination rate in just one year - holding out the hope that foresters will be able to boost the rate of regeneration and help the tree to flourish in healthy numbers once again.

Scientists from the Commission's Forest Research agency and from the Royal Botanic Garden Edinburgh have been working on the problem with colleagues at Chile's Austral de Chile University in Valdivia. Initiated through the Botanic Garden's International Conifer Conservation Programme (ICCP), funding has also been provided by the UK Government's Darwin Initiative for the Survival of Species.

Dr Peter Gosling from Forest Research explained,

"By integrating good collection methods, fruit handling, local storage conditions, careful transport and a unique combination of pulp removal, washing, moist pre-germination treatment, surgical dissection and embryo culture, we've achieved 34 per cent germination in just under one year.

"We started with 262 seeds, and by using these techniques we succeeded in getting 89 seedlings established within a year. That's more than double the number of plum yews in some groups of the trees in their native area!"

The seedlings are being cared for at Forest Research's Alice Holt Lodge research station near Farnham in Surrey, and once they're big enough they'll be planted out in the Forestry Commission's National Pinetum at Bedgebury in Kent.

Dr Martin Gardner from the Royal Botanic Garden Edinburgh added,

"We cannot afford to lose a single species from our planet, and definitely not a significant tree such as Prumnopitys andina , which is an important component of the Chilean rainforests.

"As technologies progress we are finding more and more important compounds that can be extracted from plants and used for medicinal treatments. Already it is known that this species has anti-fungal properties that could one day play an important role in the treatment of human diseases.

"So this is an exciting breakthrough. The technique is now assisting Chilean researchers in conservation programmes to restore degraded forest environments in Chile.

"One restoration programme has already begun in partnership with a local landowner, who has fenced off a planting site to keep animals away from the young trees.

"We also hope that conservation programmes will generate employment opportunities in nurseries for poor local people, and help poorer landowners to make sustainable economic use of their forests, for example, by small-scale cultivation and sale of the native trees and plants growing on their land."

Paulina Hechenleitner, from Austral de Chile University, added,

"We are very pleased to have been part of a collaborative initiative involving leading UK research institutes to help understand more about the propagation methods that can be used to assist the conservation of one of Chile’s most important conifer species."

The techniques and treatments have been published in the Royal Botanic Garden Edinburgh's journal, Sibbaldia.

NOTES TO EDITOR:

1. The Chilean plum yew is a member of the podocarp family (genus Podocarpaceae ). It grows to about 15 metres (50 feet) tall and often occurs on the margins of large rivers in the Chilean Andes, with one known population across the border in Argentina. There are fewer than 12 known populations left in the wild, and most of these groups have fewer than 100 trees each. The timber is prized for fine furniture (although felling for timber production is not thought to be a current problem), and local people eat the sweet, fleshy cones. Wildfires, indiscriminate logging and hydro-electric development have greatly reduced the trees' numbers, and although the female trees produce plenty of seed, regeneration is generally poor, partly because many of the seeds are eaten by domesticated animals such as pigs and goats introduced to the trees' habitat by farmers.
2. There are Chilean plum yews growing in botanic gardens, arboreta and private collections around the world, but most of these are thought to have been propagated from cuttings rather than grown from seed, giving rise to scientists' doubts about how much genetic variety they represent. Scientists are also investigating the genetic integrity of the remaining wild populations of the tree.
3. The technique developed for improving the germination rate of Prumnopitys andina involves:
   • removing the fleshy sarcotesta (the olive-green, covering 'berry');
   • thoroughly washing the seed-coat;
   • ‘pretreating’ the imbibed seeds by incubating them in moist peat and sand at a daily alternating 10/15°C for several months (to allow ‘ maturation’ or ‘after-ripening’/‘dormancy breakage’: the researchers are not yet sure which of these processes is occurring);
   • carefully cracking the seed coat in a vice and extracting the embryo;
   • culturing clean, firm, healthy (‘viable’) embryos on moist filter paper at a daily alternating 20/30°C (with lights during the 30°C phase);
   • where necessary, freeing the cotyledons (embryo 'leaves') of all seedlings that become trapped in the female gametophyte (the embryo food store); and
   • transplanting the seedlings to conventional nursery practice. A further 1008 seeds are continuing ‘pre-treatment’ to investigate whether this will increase the proportion of seedlings achieved or, better still, lead to a less labour-intensive means of ensuring that seedlings emerge from intact seeds.
4. The Darwin Initiative for the Survival of Species is a grants programme that promotes conservation of biodiversity and sustainable use of resources around the world. It is funded and administered by the UK Government's Department for Environment, Food & Rural Affairs (Defra). For further information, visit www.darwin.gov.uk.
5. Forest Research is an agency of the Forestry Commission, which is the government department for forestry in Great Britain. It carries out world-class scientific research and technical development relevant to forestry for a range of internal and external clients. For further information, visit www.forestresearch.gov.uk and www.forestry.gov.uk/research
6. The Royal Botanic Garden Edinburgh, also known as the National Botanic Gardens of Scotland, is a scientific institution dedicated to discovering and describing plants and their relationships, evolution, conservation and biology. It is supported by the Scottish Executive's Environment & Rural Affairs Department, and has sites in Edinburgh, Dawyck in the Scottish Borders, Benmore in Argyll and Logan in Dumfries & Galloway. For further information visit www.rbge.org.uk.

NEWS MEDIA CONTACTS:

• Forest Research / Forestry Commission - Charlton Clark, 0131 314 6500 or 07810 181067;
• Royal Botanic Garden Edinburgh - Martin Gardner or Philip Thomas, 0131 552 7171 ;
• Universidad Austral de Chile - Paulina Hechenleitner, 00 56 63 221277; phechenleitner@uach.cl;
• Bedgebury National Arboretum – Chris Reynolds, 01580 213043 or Dan Luscombe, 01580 211044 / 07881 835929