Brazil, UK develop wheat resistant to Fusarium Head Blight through partnership

A partnership between Brazilian and British researchers has simplified the production of wheat plants resistant to Fusarium Wilt and Rice Blast Fungus. Tens of Brazilian genotypes had already been characterized in the search for the FHB1 gene, used in genetic wheat programs run by major global research institutions.

Fusarium Wilt is one of the most critical diseases affecting wheat production in the world. Besides causing yield loss and low quality, the disease can also contaminate grains with microtoxins, a toxic substance produced by the fungus. In years with heavy rainfall, epidemics are frequently reported in the south of Brazil, affecting 90% of the produced wheat. Currently, levels of tolerance to Fusarium Wilt in cultivars are low and the use of fungicides has not been efficient.

A partnership between the Brazilian Agricultural Research Company (Embrapa) and the Biotechnology and Biological Sciences Research Council (BBSRC) allowed the exchange of researchers and genetic resources between the two institutions. Embrapa researcher Pedro Luiz Scheeren worked at the John Innes Center (JIC) in Norwich, England, from May to August 2013, attempting to isolate the FHB1 gene for its genetic resistance to Fusarium Wilt, a Brazilian germplasm in wheat.

The research focused on a collection of Brazilian wheat cultivars grown that year, which were taken to JIC for characterization by advanced biotechnological tools adept at identifying gene resistance. “The final response was deceptive. We concluded that none of the 96 cultivars of Brazilian wheat in use in the market had the FHB1 gene, which is capable of mitigating the impact of the disease on the crops,” stated Scheeren.

The alternative for Brazilian wheat is to work on the incorporation of a resistance gene in the cultivars through genetic improvement. Currently, FHB1 is the best source of resistance to Fusarium Wilt in the world, according to several studies. Introduced through the wheat variety Sumai 3, originating in China, the gene is capable of codifying a protein with antifungal properties.

"We are crossing two Brazilian cultivars with Sumai to ensure resistance. As soon as we see promising results from the assisted selection, we will transfer this resistant gene to the new cultivars for production under the improvement program for wheat at Embrapa. We aim to produce plants that are less affected by Fusarium Wilt until we gradually suppress the presence of the disease,” noted Scheeren. The researchers expect to create a cultivar more resistant to Fusarium in the next three years.

For JIC researcher Paul Nicholson, the use of molecular markers eases plant selection because it helps to locate the gene even during years when the disease was not widespread. According to him, in England, there are diverse wheat varieties available containing the FHB1 gene, which reduces the presence of the disease in the crop.

Some 18 researchers and the support staff of the two institutions have been studying genetic resistance to Fusarium Wilt and Blast Fungus in wheat.