BARC to test its experimental wheat lines in Kenya

If BARC succeeds in obtaining resistant mutants which resist attack of the virulent stem rust Ug99, it will be a significant development as wheat scientists all over the world are looking for resistance to this disease.

The evolving pathogen Ug99 may pose even greater threat to global wheat production than the original Ug99 (identified first in Uganda in 1999), according to Food and Agricultural Organisation.

The virulent fungus race has moved to Kenya, Ethiopia, Sudan, Yemen and heading towards South Asia and recently reached Iran.

"The new mutants will be developed by treating the seeds of popular varieties of wheat with radiations to induce genetic variation and these may include the required resistance mutation," Dr. S G Bhagwat, Head, Mutation Breeding Section of BARC told PTI.

About the status of research on the resistant variety, Bhagwat said, the mutation often expresses in the second generation after radiation treatment.

"Currently, the mutagenised lines are undergoing generation advancement. Since the pathogen does not occur in India, some selected variants will be tested in Kenya where the disease is prevalent."

"We have applied for permission from the National Biodiversity Authority (NBA) to to send the experimental seed material to Kenya for screening against 'Ug99' race. The seeds will be sent through the National Bureau of Plant Genetic Resources (NBPGR)," Bhagwat said.
If a resistant mutant exists in the seeds sent to Kenya, it will be observed in this population of plants. Then screening and identification is a matter of months," he said.

The identified mutant will then be tested in comparative trials as per the normal protocol.
BARC is participating in an international project initiated by the International Atomic Energy Agency (IAEA) through which screening in Kenya will be carried out.

The deadly fungus was first identified in Uganda in 1999 and is named Ug99 for its place and date of identification.

The Ug99 grows on the stems and other parts of wheat plant and gets nutrition from the plant ultimately weakening the stem so that plants can no longer stand upright. Infected plants produce fewer seeds and may die.

Besides BARC, the Indian Council of Agricultural Research Labs are also working on the problem of Ug99. But their approach is based on selection from existing resistance or recombination breeding.

"But the radiation induced mutation approach has an advantage that it can produce the resistance trait in the specific variety that is being used for the experiment while preserving its good characteristics," Bhagwat said.

In India, there are 30 races of stem rust of wheat detected in different parts and these are kept under check by cultivation of varieties which carry complete or partial resistance to the existing races, Bhagwat said.

Asked how Ug99 is different from other races of rust, he said, "Ug99 is different because it can infect wheat varieties which do not support significant infection by existing stem rust races."

The incorporation of rust resistance genes is at the level of the scientists, the farmers contribute by cultivating resistant varieties, the BARC agriculture scientist said.

Asked besides Ug99, are there any other experiments to study and improve traits of wheat in the country, Bhagwat said, there are several experiments at various stages and will be published soon.

Meanwhile, Stanislaus F D’Souza, Head, Nuclear Agriculture and Biotechnology Division, BARC said so far 39 new crop varieties developed at the Research Centre have been released and Gazette notified by the Ministry of Agriculture for commercial cultivation.

"These include 20 in oilseeds, 17 in pulses and one each in rice and jute. Major contribution has been in oilseeds and pulses, especially in groundnut, mung and urad and are very popular among the farming community and grown extensively in the country benefiting farmers," he added.