Substantial reductions in a deadly root disease of wheat crops and corresponding increases in yields of grain and straw mark a significant advance in the continuing war to protect the staple cereal from the ravages of the take-all soil pathogen, to which it is highly susceptible.
Researchers have now shown that careful selection of the variety of the first wheat in a new cropping cycle can reduce the disease's severity and increase yields in the second crop variety. Their findings are published today in Scientific Reports.
Furthermore, these benefits are irrespective of the second variety or its susceptibility to this fungal pathogen. And though the findings relate to short rotations, in which the type of crop is changed after just two harvests, the benefits seem to continue for subsequent harvests.
"In rotation field experiments, we demonstrated the considerable and lasting impact of the choice of the first wheat variety on root health and the yields of the second wheat," says Vanessa McMillan, a plant pathologist at Rothamsted Research who led the study.
"There was a consistent reduction in take-all disease and a grain yield advantage of between 0.2 and 2.4 tonnes per hectare (or up to 25% of average UK yields)," adds McMillan. "The results were consistent across multiple field seasons and sites."
The research team had already identified and reported a new genetic trait in wheat, called take-all inoculum build-up (TAB); in spite of wheat's high susceptibility to take-all disease, there are low TAB varieties that minimise the presence of the pathogen in soil.
The team's latest findings show that using one of these low TAB varieties in Year-1 of a cycle generates the benefits for the second crop. The team is now investigating how lasting are these benefits in subsequent crops.
Take-all, caused by the soil-borne fungus Gaeumannomyces tritici, is the major root disease of wheat worldwide. Infection causes yellowing of crops and stunted growth, typically developing as patches that can spread throughout fields. Few chemical seed treatments are available.
Genetic traits, such as TAB, could provide a new way of combating take-all, particularly in association with cultural control techniques, such as crop rotation, within an integrated disease management strategy.
As part of the latest work, the team sampled commercial wheat varieties across a range of field sites from the AHDB Recommended List that demonstrated variation in TAB properties of modern wheats currently being grown by farmers in the UK.
"While there was evidence of significant interaction between the varieties across the trial sites, we could still identify a small number of low TAB varieties across all sites," notes McMillan, who also leads the take-all research group at Rothamsted.
Her group is currently investigating the potential mechanisms underlying the low TAB trait, including exploring whether low TAB varieties create an antagonistic rhizosphere environment against the take-all fungus.
Rothamsted's take-all research group is part of one of the institute's five strategic programmes, namely Designing Future Wheat, a multi-institute initiative that focuses specifically on improving overall crop val-ue and resilience. The work is funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and the Lawes Agricultural Trust (LAT). The rotation field experiments formed part of the core project of the Wheat Genetic Improvement Network (WGIN), which is supported by the Department for Environment, Food and Rural Affairs (Defra).
NOTES TO EDITORS
Rothamsted Research contacts:
Vanessa McMillan, Plant Pathologist
Tel: +44 (0) 1582 938 448/527
Susan Watts, Head of Communications
Tel: +44 (0) 1582 938 109
Mob: +44 (0) 7964 832 719
About Rothamsted Research
Rothamsted Research is the longest-running agricultural research institute in the world. We work from gene to field with a proud history of ground-breaking discoveries, from crop treatment to crop protection, from statistical interpretation to soils management. Our founders, in 1843, were the pioneers of modern agriculture, and we are known for our imaginative science and our collaborative influence on fresh thinking and farming practices. Through independent science and innovation, we make significant contributions to improving agri-food systems in the UK and internationally. In terms of the institute's economic contribution, the cumulative impact of our work in the UK was calculated to exceed £3000 million a year in 2015 (Rothamsted Research and the Value of Excellence: A synthesis of the available evidence, by Séan Rickard). Our strength lies in our systems approach, which combines science and strategic research, interdisciplinary teams and partnerships.
Rothamsted is also home to three unique resources. These National Capabilities are open to researchers from all over the world: The Long-Term Experiments, Rothamsted Insect Survey and the North Wyke Farm Platform.
We are strategically funded by the Biotechnology and Biological Sciences Research Council (BBSRC), with additional support from other national and international funding streams, and from industry. We are also supported by the Lawes Agricultural Trust (LAT).For more information, visit https:/
The Biotechnology and Biological Sciences Research Council is part of UK Research and Innovation, a non-departmental public body funded by a grant-in-aid from the UK government.
BBSRC invests in world-class bioscience research and training on behalf of the UK public. Our aim is to further scientific knowledge, to promote economic growth, wealth and job creation and to improve quality of life in the UK and beyond.
Funded by government, BBSRC invested £469 million in world-class bioscience in 2016-17. We support research and training in universities and strategically funded institutes. BBSRC research and the people we fund are helping society to meet major challenges, including food security, green energy and healthier, longer lives. Our investments underpin important UK economic sectors, such as farming, food, industrial biotechnology and pharmaceuticals.
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The Lawes Agricultural Trust, established in 1889 by Sir John Bennet Lawes, supports Rothamsted Research's national and international agricultural science through the provision of land, facilities and funding. LAT, a charitable trust, owns the estates at Harpenden and Broom's Barn, including many of the buildings used by Rothamsted Research. LAT provides an annual research grant to the Director, accommodation for nearly 200 people, and support for fellowships for young scientists from developing countries. LAT also makes capital grants to help modernise facilities at Rothamsted, or invests in new buildings.