Archive Article: 1997/09/20
DR FINLAY Dale doesnt look much like a bookie. But, as one of three potato breeders at the Scottish Crop Research Institute (SCRI) at Dundee, thats how he sometimes feels: "When you take two parents, the odds are 10,000 to one that youll find a cross with, say, the six disease characteristics that youre aiming for." It doesnt help that many of the desired attributes are polygenic – that is, determined by more than one gene.
Speaking at a variety day hosted by Nickerson Seeds, SCRIs commercial partner, Dr Dale describes how it can take up to 15 years to develop a new variety. But targeted breeding techniques at SCRI have managed to reduced this lag, and make the job more efficient, meaning there are fewer rejects to discard in the process.
Even so, breeders still feel a little at the mercy of the market. "I find the supermarkets domination of the fresh market slightly concerning. They have undoubted power, but remove themselves from market responsibility. So a variety can be on their list one year and dropped the next, yet there might be 10 years worth of seed in the pipeline."
Methods such as cell fusion, where an electric current is used to break down cell walls and fuse the cells together, will at least reduce the breeders response time yet further. The aim – to reduce the process of producing a new variety to one year is, admits Dr Dale, ambitious. But the technology already exists to speed things up.
For instance, resistance to leaf roll virus is available off the shelf. "If you want it, its there," he states. And theres good progress, too, towards potato mop top and tobacco rattle virus resistance and better pallida resistance.
The urge to reduce chemical inputs is shunting natural health up the list of priorities for new varieties and, meanwhile, will determine which of the existing ones will be grown, explains Dr Dale. "Potatoes are the heaviest users of agrochemicals and consumers are tuning in.
"The variety Stirling, for instance, rated 8 for foliage blight and 7 for tuber blight, has been identified by the Henry Doubleday Research Association as having a real benefit in reducing blight sprays. Instead of fortnightly applications, it may only need two or three sprays all season."
PCN resistance is one of Dr Dales special interests. "Up to 70-80% of yield can be lost to high infestations. The chemicals used to control nematodes are highly toxic and environmentally questionable at best." One solution is offered by the natural resistance found in certain wild relatives which breeders are attempting to harness.
Sprout suppressants are a particular area of consumer concern. "Theyre applied straight onto the product so theyre going to be first on the hit list. The good news is that weve identified the germplasm that will allow potatoes to be stored at 4íC without the associated problem of deteriorating fry colour," says Dr Dale.