Results of Developed Lines Will Appear After 10 Years

Reprinted from "Potecal" July 2025 issue (No. 159)

Text by Kazuyoshi Hosaka (Specially Appointed Professor, Potato Genetic Resources Development Course, Obihiro University of Agriculture and Veterinary Medicine, National University Corporation Hokkaido National University Organization)

To support the growth of the world population, the total production of major crops continues to increase, and yields per unit area are also rising. Potato production in Japan increased rapidly after the war, and yields rose from 1 ton per 10a to about 3.5 tons by the year 2000, but this is thanks to cultivation (fertilization and mechanization) and pest control (establishment of a disease-free seed potato supply system and pesticides) technologies. Since varieties from over 100 years ago, such as "Danshaku" (Irish Cobbler) and "May Queen," are still the main varieties, it is difficult to say that genetic improvement (breeding) has contributed to yield increases. Breeding has prioritized varieties suitable for specific uses—from fresh potatoes to those for starch, potato chips, fries, salads, and croquettes—as well as varieties resistant to potato cyst nematodes and common scab, while yield potential has been secondary. Breeding until now has been problem-solving oriented. Although the potato genome was decoded in 2011, subsequent research has only served to make us realize the complexity of the potato genome.

Great genetic diversity is necessary to create groundbreaking varieties. Since both Japanese and foreign varieties originally derive from the same limited sources, collecting foreign varieties does not lead to an expansion of diversity. Compared to other major crops, potatoes have a large number of wild species and possess vast genetic resources. To utilize these efficiently, an endowed chair was established at Obihiro University of Agriculture and Veterinary Medicine in 2013, based on donations from potato processing manufacturers and producer organizations. The "Potato Genetic Resources Development Laboratory," which was formed based on this, plays the role of creating new parent lines using cultivated potatoes from the Andean region of origin and related wild species, and supplying them to breeders. How much the lines we have created have contributed to new varieties will only be known in 10 or 20 years.

On the other hand, the Sli gene that I discovered and published in 1998 has begun to see the light of day in the form of F1 potato varieties after more than 20 years. The Dutch private company "Solynta" cultivated the first F1 varieties in Kenya, and in 2024, they are also conducting trial cultivation in Japan. In the United States, state universities have joined forces to develop F1 varieties as "The Potato 2.0 Project." China is also utilizing genomic information to advance the development of F1 varieties on a large scale. F1 varieties are grown by sowing seeds, not from seed potatoes. Potato seeds are about the size of sesame seeds and can be stored in a refrigerator for about 30 years. They can be taken out of the refrigerator and used whenever needed. There is no need to worry about huge seed potato storage facilities or transportation methods. Since seeds do not contain viruses, the current disease-free seed potato production system, which starts from pre-basic seed potatoes, will change significantly. If that happens, a new seed industry might begin where F1 varieties are bred in the cool climate of Hokkaido and seeds are sold all over the world.

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Research Frontline from the Potato Genetic Resources Development Laboratory, Obihiro University of Agriculture and Veterinary Medicine
Autumn 2025 Spring 2026