Breeding Methods for Potatoes

Pollination

• Natural pollination results in distinctive, hardy potato breeds. Plant rows of all the potato varieties you want to breed together, with about ten plants in each row. Put a beehive between each row. The potato flowers, pollinated by the bees, will bear fruit. You should aim to pick between 50 and 100 fruits. Each of these fruits will contain approximately 300 seeds, and all the seeds will be genetically different from one another by the time you harvest them.

Separating Seeds

• Once you have harvested your potato fruits, put each type of fruit separately into a blender. Cover with water and blend just enough to break up the pulp of the fruit, so the seeds can be retrieved. Put each mixture in a plastic bowl for 24 hours. The fruit debris will float, and the seeds will sink. It will take several washings before your seeds are clean. Drain them with a coffee filter and put them on paper towel to dry. If stored in an airtight jar with silica gel, they will keep for several years.

Sowing Seeds

• In the spring, sow each of your seed varieties in a separate row using a hand seed drill. The weakest seedlings will succumb to beetles and blight. The most resistant seedlings should be marked with a colored stick. They are your future breeding stock. Harvest their fruit in the autumn and repeat the process from the previous year. These potato plants are developing horizontal resistance, which means they are learning to resist different strains of the blight fungus. Vertically resistant plants have only learned to resist one strain.

Additional Facts

• Potatoes come in two genetic varieties: tetraploid and diploid. The majority of potatoes are tetraploid, though the Mayan Gold and a few other varieties are diploid. A tetraploid organism has double the amount of genetic material that a diploid organism has. This genetic variety means that the exact outcome of breeding two tetraploid organisms is difficult to predict. However, it also means that as new diseases threaten potato crops, breeders will continually be able to find unique, natural ways of resisting them.