Genetically Modified Potato

Over the last few years, potatoes have been losing importance as a food crop. The crop's prospects in the starch and chemical industry, however, have been growing for quite some time. For starch potatoes, taste isn't what's important. Instead, emphasis is placed on the quality and composition of the starch. An optimised starch potato could be making its way to fields in Europe soon. This new potato cultivar is genetically modified.

Only one in four potatoes grown in Europe actually gets eaten by people. Almost half end up being fed to livestock. The remaing one quarter are used as raw material in the production of alcohol and starch.


Potatoes are becoming more and more important as renewable raw materials for the starch industry. The starch produced in potatoes, however, isn't in an ideal form. It's composed of a mixture of two different kinds of starch: amylose and amylopectin. These two kinds of starch have very different properties.

Amylopectin, making up 80 percent of the starch content in potatoes, consists of large, highly-branched molecules. It is very useful in the food, paper, and chemical industries as paste, glue or as a lubricant.

Amylose is made up of long, chain-like molecules and is used predominantly in the production of films and foils.

Both of these kinds of starch are useful for human nutrition. But for the processing industry, a mixture of different starches is a problem. Industry must separate the two kinds of starch using expensive processes that take a toll on the environment. This is why plant breeders are working hard to develop potatoes that produce only one type of starch. Right now, emphasis has been placed upon developing potatoes containing only amylopectin, due to its diverse applications.

Classical breeding methods have not yet been able to provide an amylose-free potato that has acceptable yield and resistance to pests and diseases. Genetic engineering (Antisense-Strategy), on the other hand, offers a targeted approach to supressing the production of amylose.

Genetically modified amylopectin potatoes have been tested in field trials for several years. In the meantime, applications have been presented to European regulatory authorities for approving the cultivation of these potatoes as a renewable raw material for starch production. Starch-modified GM potatoes could be growing in European fields soon.


Resistance to pests and diseases

Attempts to confer pest and disease resistance to potatoes using genetic engineering haven't been quite as successful. Several GM potato cultivars with improved  resistance to viruses and to the potato beetle have been approved in the US and in Canada. In 1999, they were planted on approximately 25,000 hectares. Since then, cultivation of GM potatoes has ceased. The GM potatoes did not prevail, because they were not delivering any economic advantages, and some larger US companies refused to take the GM potatoes for further processing.