New stem rust-resistant wheat varieties introduced

New stem rust-resistant wheat varieties introduced

Kenyan university debuts two new varieties of disease-resistant wheat to the nation's farmers.

AS a result of a multinational effort supported by the International Atomic Energy Agency (IAEA) and the U.N. Food & Agriculture Organization (FAO), two new Ug99-resistant wheat varieties were showcased to Kenyan farmers by Eldoret University's School of Agriculture & Biotechnology this month.

For more than 30 years, wheat stem rust was under control, but a reawakening of the disease was discovered in 1999 in Uganda and swiftly spread to neighboring Kenya.

The wheat stem rust disease, caused by the strain of the fungus known as Ug99 — so named after the fungus destroyed the wheat harvest in Uganda in 1999 — is spreading rapidly across eastern Africa and the Middle East. Regions directly affected by Ug99 account for more than 37% of global wheat production.

The wind-carried spores have spread to Iran, Yemen and South Yemen and also threaten crops as far away as India.

If not prevented, the disease can destroy 70-100% of the wheat crop's yield.

"Wheat rusts, particularly the Ug99 strain, are a major threat to food security because rust epidemics can result in devastating yield losses," FAO director-general Jose Graziano da Silva said.

The rust-resistant wheat varieties were developed with the support of an IAEA technical cooperation project, "Responding to the Transboundary Threat of Wheat Black Stem Rust (Ug99)," which involved more than 20 nations and international organizations.

The varieties were developed using a nuclear technique for crop improvement known as mutation breeding. By exposing seeds, or plant tissue, to radiation, scientists accelerate the natural process of mutation, and breeders then are able to select and develop new varieties.

"Improving food security in developing countries through the use of nuclear techniques is an important priority of the IAEA," Yukiya Amano, director general of IAEA, said. "I am pleased that we have been able to make an important contribution to fighting wheat rust."

In 2009, Miriam Kinyua, a Kenyan plant breeder, sent 10 kg of five varieties of wheat seed to the FAO/IAEA laboratories in Seibersdorf, south of Vienna, Austria, where they were irradiated for mutation breeding.

These seeds were returned to Kenya, where they were planted in a hot spot for the Ug99 disease for screening and selection.

Kinyua and her colleagues at the University of Eldoret's biotechnology department identified eight lines that were resistant to Ug99. Four of these lines were submitted for national performance trials in Kenya, and two were officially approved as varieties by the national committee of the Ministry of Agriculture.

About six tons of seeds of the new varieties will be made available this month for the next planting season in Kenya.

Volume:85 Issue:38

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