The breeding of potato is a long term process: after making the cross it takes about 10 years before a new variety can be introduced into the market. The breeding program starts with the selection of two plants that will be used as crossing parents. By crossing the parent plants, the breeder tries to combine the good qualities of both parents in its progeny. These plants can be existing varieties but also genotypes from a pre-breeding program or wild Solanum species. They are put in the greenhouse in February and every year between 200 and 300 different crossing combinations are made. When a cross is successful a berry is formed containing about 100 seeds. The seeds are removed from the berries, cleaned and saved for sowing in the next year. Depending on the breeding goal 100 till 2,000 seeds of every cross are sown and transplanted two weeks after germination. Eighteen weeks after transplanting the seedlings one tuber of each plant is harvested and stored.
In the first three years the clones are tested in the field for agricultural traits like number and shape of the tubers, stolon length, yield and starch content. Only the clones that perform well on these traits are selected. Besides this selection the clones are also tested in the laboratory for resistance to potato cyst nematodes and wart disease. In the following years the clones are tested on a number of trial fields. This is necessary to determine the adaptation of the clones to diverse environments. Besides various trial fields in The Netherlands Averis Seeds also has trial fields in Germany, France, Sweden and Denmark. The clones are also tested on trial fields for resistance to Phytophthora, a number of viruses, common scab and wart disease.
After six years of selection the clones will be appointed to the official variety testing. Depending on the country where the clones are appointed to, the clones can be put on a official variety list and subsequently on the European Variety List. From this point it is necessary to have enough seed potatoes to provide the farmers. Therefore Averis Seeds will multiply the variety in vitro and produce mini tubers of it.