IF YOUR household celebrates Christmas, you may well have chosen to put up an artificial tree this year. Fake Christmas trees have been around almost as long as the real thing, but they first began to sell in large numbers in the 1930s, when a toilet-brush manufacturer realised it could make them cheaply by slightly altering its product. Artificial trees are now more popular than the real thing, some surveys suggest, not least because they can last for years and don’t drop annoying needles all over the carpet.
But tree growers aren’t giving up without a fight. They have long been trying to develop more attractive trees to win back customers – and recently, there have been some significant advances. In the not-too-distant future, it may be possible to create trees that not only hold onto their needles but also have distinctive scents or unusual colours.
For those who regard the idea of buying an artificial tree as heresy, you can already and caring for it properly. The traditional Christmas tree in Europe is the Norway spruce, with its piney scent. But it loses its needles easily compared with species such as the Nordman fir, now the bestseller in Europe, and the Douglas fir, popular in the US.
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Needle drop can be reduced even further by finding natural mutants that tend to hold onto their leaves. “Over the years, I’ve obtained a collection of individual trees that have excellent needle retention,” says of Washington State University in Puyallup, who leads a tree-breeding programme. Some are already being propagated in nurseries, but this is a slow process. It takes years to grow and assess trees by painstakingly counting dropped needles.
“This year the Norway spruce became the first conifer to have its genome sequenced”
To speed things up, several groups are hunting for the genes responsible. This would not only give researchers the option of genetically engineering trees that don’t drop needles, it would also make it far easier to find natural needle-retaining individuals, or to breed them. The hope is that the same genes will turn out to control needle drop in many different species.
The hunt became a whole lot easier this year when the Norway spruce . Meanwhile, a big clue to which genes are involved in making leaves fall came courtesy of the “lab rat” of plants, the thale cress. and his colleagues at the University of Missouri in Columbia . “These are all modified leaves,” says Walker. So tweaking the equivalent genes in Christmas trees might prevent needle loss. Retained needles would still dry out though, Walker cautions, potentially posing a fire risk.
Keeping carpets needle-free isn’t the only item on the wish list, though. “What sells is novelty,” says of North Carolina State University in Raleigh, who studies forestry and genomics. The most feasible exotic traits to introduce could be aromas, he says. Trees such as balsam firs already have fragrant, pine-like odours. But it might be possible to use genes from other trees or plants to produce scents such as vanilla, cinnamon and lemon.
Trees with yellow or red needles may also be possible. “Blue and white spruce already have differently coloured waxes on the outside of their needles, and all seem to be under metabolic control that could be manipulated,” says Sederoff.
“The most feasible exotic traits to introduce could be aromas such as vanilla and cinnamon”
But don’t expect trees that light up by themselves. While many have been created in labs, the light is . In conifer needles, the wax and other pigments would block the light, making the glow even dimmer. “This wouldn’t be a trivial project,” says Sederoff.
Trees with coloured and scented needles have yet to be created, but is already growing genetically modified Nordman firs at the University of Copenhagen Botanical Garden in Denmark. His team is trying to produce faster-growing trees, so they are available sooner for sale. “But legislation and public concerns mean that we are still very far away from commercial production of genetically engineered Christmas trees,” he says. Indeed, GM trees could fall into an unhappy middle ground. They will never offer the stick-it-in-a-cupboard convenience of artificial trees, nor will they appeal to traditionalists looking for “the real thing”.
But Find has an idea that might win some people over: Christmas trees that produce a valuable product, such as a perfume or pharmaceutical, that can be extracted after the 12 days are over. “You could argue that growing a tree for eight to 10 years then only using it over a few days of Christmas is a waste, so why not invent a double use,” he says.
This article appeared in print under the headline “All spruced up”
