Deliberate release of genetically modified trees

An abundance of poplars

Compared with genetically modified agricultural crops, which are already grown commercially throughout the world, transgenic woody plants play only a minor part. Most of the field trials of genetically modified trees have been conducted in the USA, Canada and Europe. The first market approval for papaya and plums with genetically engineered viral resistance has been granted in the USA. In China the first transgenic black poplar clones with insect resistance were released for commercial use in 2002.

USA. Until now, by far the largest release of genetically modified trees has been undertaken in the USA, mainly of poplars. The new characteristics imparted by the introduction of genes are aimed primarily at altering the quality of the timber and increasing the biomass production. Both male and female sterile poplars, which cannot propagate have been tested in field trials.

Crops Number
Poplar 203
Pine 154
Eucalyptus 82
Apple 67

Deliberate release of genetically modified treesin the USA. (April 2012)
Source: ISB Information systems for biotechnology

Crops Country Number
Poplar F,D,S,GB,E,N,PL,B 30
Forest trees FIN 10
Apple GB,NL,S,B,D 10
Orange E 7
Plum CZ,RO 3
Cherry I 3
Birne S 2
Eucalyptus GB,E 2
Olive I 2
Paradise apple NL 2
Lemon I 1

Deliberate release of genetically modified treesin the EU. (April 2012)
Source EU: Federal Office of Consumer Protection and Food Safety (BVL)
A deliberate release application may involve several releases of a GMO at different sites over several years.

In mid-May 2010 the US Department of Agriculture (USDA) approved large-scale field trials with eucalyptus. A gene has been introduced into the trees that makes them less sensitive to cold. Until now cultivation of eucalyptus was only possible on the southern tip of Florida; frost tolerance could mean that cultivation would be possible in other parts of the USA.

Europe. In the EU as elsewhere, genetic modifications and field trials of trees focus primarily on poplars. The first official release trial of transgenic poplars in the EU took place in Belgium in 1988. Subsequent field trials with poplars have taken place in France (11), Sweden (6), Germany (4), Spain (4), the UK (2), Norway (1) and Poland (1).

Traits of commercial significance include the amount of the lignin in the wood, the optimized biomass production and the remediation of soils contaminated with heavy metals.

Around 70 deliberate releases of genetically modified trees were approved by national authorities in Europe between 1993 and 2011. Among these, besides poplars, are timbers such as birch, spruce, and pine, as well as fruit trees such as apple, cherry or plum.

Germany: Four deliberate releases of transgenic trees have taken place in Germany so far. In 1996 the Federal Research Centre for Forestry and Forest Products (BFH) in Grosshansdorf started the first deliberate release trial of genetically modified aspens. This trial was concerned with the influence of the environment on the genetic stability of the new traits over an extended period of time. The BFH obtained approval for a further trial in 2000. Two deliberate releases with poplars took place at the University of Freiburg as part of BMBF-funded biosafety research (2002, 2003). This time the focus was on soil decontamination using genetically modified poplars. Biological safety research projects have investigated whether the genetic modifications are stable in the field, and whether they have effects on the beneficial soil fungi that live in symbiosis with the trees.

In 2003 the Federal Centre for Breeding Research on Cultivated Plants (since 2008 Julius Kuehn Institute) initially obtained approval for a release trial of genetically modified apples with resistance to fire blight, but approval was subsequently withdrawn following pressure from the German government at the time.

World: The publication of the complete genetic structure of the American balsam poplar in September 2004 led people to expect that a range of new genes of commercial interest would be identified and isolated in the near future which would then be available for genetic work on trees. Since then, researchers have discovered that trees basically have the same set of genes as herbaceous plants, but that they are regulated in a different way. This applies in particular to the regulation of genes for wood formation and longevity. However, most of this data has not been published in detail, since attempts are being made to patent the findings.