Rust, caused by Melampsora, is the most serious problem for the willow (Salix), a main renewable energy crop and important vegetation for conservation in Europe. The European Union is committed to a 15% reduction of greenhouse gas emissions by 2010 and a large increase of energy production from renewable sources is expected. Economic and environmental considerations rule out the use of fungicide for rust control so this project will develop integrated rust control measures without fungicide. It will address population biology and epidemiology of Melampsora, sources and genetics of rust resistance in Salix, function of host mixtures against rust, and the potential of using a mycoparasite for biological control. The project will provide measures towards breeding for durable resistance, designing optimum mixtures and deploying the biocontrol agent to suppress rust disease.
The project is to develop, using host resistance and natural processes, integrated, low-cost and environment-friendly measures to control rust in willow plantations for renewable energy and conservation. The main objectives are:
1) to determine the variation, spread and life cycle of Melampsora in order to assess disease risks in willow
2) to determine sources and genetic behaviour of rust resistance
3) to clarify natural defences of willow mixtures against rust
4) to determine the potential of deploying the mycoparasite Sphaerellopsis filum for biological control
5) to recommend practical measures towards breeding for durable resistance, optimisation of clonal mixtures and the effective deployment of the biological control agent.
Progress to Date
The project has made excellent progress during the past three years and, in many respects, has achieved results better than was expected.
To identify Melampsora species/forms on willows occurring in Europe, rust-infected leaves were collected from a wide range of current and potential biomass willows in central, northern and western Europe. Identification of Melampsora species/forms was carried out and the colour and size of pustules, positions of uredinia and pathogenicity of rusts were examined.
Of the 213 AFLP markers scored, several were found to be exclusive to different form species. This would provide an opportunity to design specific primers to identify certain form species. From the AFLP profile, the five pathotypes appeared to be genetically distinct.
To determine the gene flow, patterns of life cycle and sources of primary inoculum in willow Melampsora, structured sampling was carried out in several important biomass willows grown in short-rotation coppice plantations in the partner countries. Studies of disease epidemiology were also carried out in the mixture trial containing different clones of S. viminalis, the most important biomass willow species. Cumulative rust scores were compiled and disease progress curves plotted to assess the disease dynamics and the performance of mixtures.
A breakthrough was achieved by using digital imaging techniques to characterise host resistance/pathogen virulence in leaf disc inoculations. Digital profiling of host/pathogen interactions greatly improved the efficiency and accuracy of disease assessments. Using this new method, a large number of samples can be processed in a single inoculation experiment and the reactions on leaf discs can be quantified.
The research results were made available to the biomass industry and public through publication of scientific papers, short articles, symposium presentations, posters and contacts with the growers.
ARABLE CROPS, CROP PESTS AND DISEASES, FORESTRY, NON-FOOD PRODUCTS
Scientist responsible for the project
Ms MING H. PEI
Weston Road, Long Ashton
BS41 9AF Bristol
United Kingdom (The) - GB
Phone: +44 1275 392181
Fax: +44 1275 394007
||University of Bristol Long Ashton Research Station (LARS)
||01 April 2000
||1 467 870 €
|Total EC contribution
||1 467 851 €
|Web address of the project