NEWS for North Dakotans
Agriculture Communication, North Dakota State University
7 Morrill Hall, Fargo, ND 58105-5665
May 25, 2000
Nowhere has the fungal disease Fusarium head blight (scab) been more thoroughly studied than in China, which in early May hosted the International Symposium of Wheat Improvement for Scab Resistance in the cities of Suzhou and Nanjing. A plant pathologist at North Dakota State University who attended that meeting says scab research is advancing evenly around the world.
"All of the research methods and facilities in China are the same as those being used here and all around the world. This is because of the communication that's occurred during the past 10 years. We're all on the same page," says Robert Stack, a professor in NDSU's plant pathology department.
At the symposium, Stack gave a presentation about the inheritance of scab resistance based on NDSU research he has conducted in cooperation with Richard Frohberg, NDSU's hard red spring wheat breeder. Accompanying Stack to China for the symposium was Robert Todd, an NDSU soil scientist who is investigating how the scab fungus survives in crop residue.
"The problems we've been seeing are being shared by scientists from around the world. We're not alone in this problem, " Stack stresses. "Despite a lot more experience in dealing with the scab issue, the Chinese are not really any further along than we are."
About 100 scientists from around the world attended the symposium, Stack says, and most were plant breeders and geneticists. Some of the presentations focused on genetic engineering and the use of pieces of plant DNA called "molecular markers," which researchers use to identify genes that are associated with a specific trait such as disease resistance. Other presentations emphasized classical breeding methods.
"Exotic sources of resistance are being found. An example would be resistance genes from a wild grass unrelated to wheat. But nobody has yet made any of these exotic sources work in a resistant, commercial wheat variety," Stack reports. "All the commercial varieties currently available have scab-resistance traits that have been derived originally from the Chinese variety Sumai3."
Since its release in 1974, Sumai3 has become recognized by wheat breeders worldwide as having superior scab resistance. Sumai3 is one of the parents of Alsen, an NDSU hard red spring wheat variety that in field trials conducted throughout multiple years has demonstrated a level of scab resistance better than virtually all commercial varieties currently available. In addition, Alsen displays resistance to other troublesome diseases affecting cereal production in the northern plains, such as wheat stem and leaf rust, and it possesses other good agronomic qualities as well. Its milling and baking qualities range from average to good.
Stack says much of China's wheat production is concentrated in the Yangtze River Valley, and the cropping system there consists of a wheat-rice double-crop rotation. He explains, "It's a subtropical environment, so they can plant all year long. This has been their cropping system for at least 1,000 years."
Under this cropping system, the Chinese plant wheat in January and harvest it in May and June. Then they flood the fields and plant rice, which they harvest in November or December. Based on recent production figures, Stack estimates that a typical Chinese wheat yield may average about 45 to 50 bushels per acre. The Chinese wheat-growing region comprises about 75 million acres. Besides wheat and rice, the Chinese also produce rapeseed and hemp in areas of the Yangtze River Valley.
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Source: Robert Stack (701) 231-7077
Editor: Dean Hulse (701) 231-6136