New form of resistance to light leaf spot discovered in oilseed rape

A team of researchers funded by BBSRC and KWS UK Ltd and led by Professor Bruce Fitt, formerly of Rothamsted Research and now at the University of Hertfordshire, has found a new form of resistance to the damaging pathogen that causes light leaf spot in oilseed rape - one of the world's most important crops.

In a paper published in Plant Pathology this week (31 August 2011), the team describes a research project carried out at Rothamsted Research that looked at disease in UK oilseed rape and came up with new findings about resistance to pathogens, which could impact on the global bid to protect arable crops from disease.

Results indicate a novel form of resistance in a specific variety of Brassica napus (oilseed rape) mediated by a single so-called "R gene". R genes are important for plant resistance to pathogens and they work in various different ways. In this case, the R gene produces a protein inside the plant that can limit pathogen asexual reproduction (which occurs regularly during the cropping season) but allows sexual reproduction (which generally occurs only once a year) and so significantly reduces the chances of a light leaf spot epidemic developing during the crop growing season.

"This is the first time that anyone has come up with a finding like this in crop resistance," said Professor Fitt, a leading authority on oilseed rape diseases. "Our results could lead to new strategies for breeding resistance against crop pathogens, leading to increased yields and reduced costs both to the farmer and the environment and reduce the need for chemical fungicides."

Oilseed rape is one of the world's most important brassica crops. Grown for the production of vegetable oil, and for use in biodiesel and animal feed, oilseed rape makes a significant contribution to the agricultural economies of Europe, Australia, Canada, China and India.

There is a major drive to increase global food yields by controlling diseases. Under new European Union legislation, some fungicides will be banned and those that will still be available will be too expensive for developing countries to use.

According to Professor Fitt, "The holy grail for crop breeders is a resistance that lasts and is not broken down by changes in pathogen populations. Examples such as the resistance we have discovered with a specific variety of oilseed rape offers new possibilities for breeders."

Source: Biotechnology and Biological Sciences Research Council