Late blight-resistant potato to help Russian farmers

Cornell University potato breeders are donating a disease-resistant potato to Russia in an effort to help combat aggressive strains of potato late blight that are threatening to devastate the nation’s essential small farms.

The Cornell-developed New York 121 potato, which also is able to fend off golden nematodes, scab and potato virus Y (PVY), will be given to Dokagene Technologies, a company specializing in producing pathogen-free seed in Russia, in a meeting and a field trip in Moscow on Aug. 20.

Dokagene will begin multiplying the potato seed, and the company hopes that it will have enough to begin commercial distribution in Russia within three or four growing seasons.

“Potato seed can become contaminated with viruses and other soil-borne pathogens,” says K. V. Raman, professor of plant breeding and executive director of the Cornell Eastern Europe Mexico (CEEM) program. “Over the next few years, Dokagene will propagate the potato seed, while Cornell expertise will act as a scientific backstop to ensure the availability of healthy seed.”

During their visit to Moscow, Cornell scientists will develop seed-multiplication procedures with Dokagene researchers. Also, they will review existing late blight projects and establish a plan for integrated late blight disease management involving a consortium of scientists from the European Union, Eastern Europe and the United States.

“After China, Russia is the second largest producer of potatoes in the world. It is considered the second bread for many parts of Russia. A severe late blight problem could put millions of people in harm’s way, and such a horrible problem could possibly destabilize the region,” says Ronnie Coffmann, Cornell professor of plant breeding.

Dokagene, a subsidiary of Troika Potato International of Elkton, Md., and Prince Edward Island, Canada, will recoup the expense of development, packaging, distribution and research by charging Russian market rates for the seed. An additional advantage for Russian farmers in growing the New York 121 variety is that the potato does not require pesticides or fertilizers.

During their visit to Russia, the Cornell group will visit the Dokagene propagation facilities near Moscow and farmers whose crops are grown on small plots called kitchen gardens.

These small farmers annually grow 3.4 million hectares (8.4 million acres) of potatoes with an average yield of 10 tons per hectare. Annual Russian potato production is between 34 million and 39 million tons .

New strains of the devastating fungus-like disease called Phytopthora infestans, or late blight, are far more aggressive than their ancestors that triggered the Irish potato famine of the 1840s. Due to commercial transportation, involving both imports and exports of potatoes, the disease has evolved through sexual mating. Unlike the old strains, the new pathogen can survive harsh winters in the soil, further endangering crops.

Because of a drought-caused potato shortage in 1976, the former Soviet Union and the nations of Eastern Europe inadvertently imported the disease in shipments of 25,000 tons of potatoes from Mexico, where the late blight pathogen originated. Beginning in the 1980s, Western Europe successfully battled the pathogen with integrated pest management measures, which included the selective use of fungicides, says William E. Fry, Cornell professor of plant pathology. Russia’s troubled economy makes pesticides unaffordable for the nation’s myriad small farms.

The story of the late blight pathogen is complex. The two mating types of the organism, A-1 and A-2, are both short-lived on their own. The Irish potato famine was caused only by A-1, which had escaped from Mexico. After the famine, the A-1 continued to be the only strain found outside Mexico, according to Fry. “Sexual reproduction didn’t occur then because partner mating types were found only in Mexico,” he says.

When potato tubers from Mexico arrived in Europe and the Soviet Union in 1976, some contained the A-2 strain, permitting A1 and A2 organisms to reproduce sexually and create oospores, the resting state of the pathogen. The pathogens proliferate freely and survive in the soil despite harsh winter conditions. When warm and moist summers arrive, they attack the potatoes and destroy the harvest. These spores reproduce and adapt other characteristics.

In the growing seasons between 1990 and 2000, the St. Petersburg region of Russia saw seven blight years, the Moscow region saw five and Siberia saw three. The federation’s Sakhalin Island, north of Hokkaido, Japan, saw blighted potato harvests every year in the 1990s.

CEEM scientists believe that the New York 121 and other varieties form the foundation for fighting late blight. The development of New York 121 dates back more than 30 years when Robert Plaisted, Cornell professor emeritus of plant breeding, acquired seeds of potato varieties grown in the Andes mountains of South America. Repeated selection for adaptation to the New York region and for disease resistance produced the E74-7, the mother of NY 121. This variety was important because of its extreme resistance to potato mosaic viruses.

In 1984 Plaisted obtained seeds, from the International Potato Center in Peru that had resistance to multiple races of the golden nematode, a soil-borne pest. One generation of breeding produced N43-288, the male parent of New York 121. This parent is mostly of Peruvian ancestry, but includes a wild species from Argentina.

By breeding the E74-7 with the N43-288 about 11 years ago, Plaisted developed a potato with multiple resistance. Typically it takes 14 years to bring a newly tested and developed potato to market, but New York 121 took less than a decade. This mid-season potato fits well with Russian needs since it is good for both boiling and baking.

Dokagene will import a total of 11 other new potato varieties into Russia, seven of which were bred at Cornell. They include:

o Reba—- A mid-season variety bred for both the potato-chip market and table use. It is resistant to the golden nematode and moderately resistant to early blight, verticillium wilt and scab.

o Salem —- A mid-season potato with high-yielding ability, bred for table stock. It is resistant to the golden nematode and scab.

o Keuka Gold —- A yellow-flesh potato, good for boiling, flavor and high yields. It is resistant to scab and golden nematodes.

o Eva —- A bright-white-skin potato, good for boiling. It is resistant to the mosaic virus, golden nematode and scab, and can be stored for a long time.

o Pike —- A round potato with a buff skin, good for making potato chips. It is resistant to golden nematode and scab.

o New York 128 —- A white, round potato for chipping. This offspring of New York 121 is resistant to the golden nematode and late blight.

CEEM’s work in Eastern Europe is funded by the Atlantic Philanthropic Service, the U.S. Department of Agriculture’s Foreign Agricultural Service, and the International Science and Technology Center.