The Survey, formerly the Physiologic Race Survey of Cereal Pathogens, commenced in 1967 following an unexpected epidemic of wheat yellow rust (Puccinia striiformis) which caused severe yield losses in the widely grown cultivar Rothwell Perdix. The epidemic was the result of the development of increased virulence for this previously resistant cultivar. Objectives The principal objective of the survey is the early detection of increased virulence compatible with resistances being exploited in commercial cultivars and breeding programmes. Secondary objectives include providing information for cultivar diversification schemes, monitoring the frequency of virulences and virulence combinations measuring the effect of changes in cultivar on the pathogen population and detecting fungicide insensitivity in some pathogens. Methods The Survey is carried out annually. In April, a list of cereal cultivars from which disease samples are requested is sent to about 100 pathologists and agronomists throughout the United Kingdom, who collect samples of infected leaves from field crops and cultivar trials and send them to the two testing centres:
Other sampling methods such as static seedling nurseries are also used. At each centre, virulence is measured by inoculating seedlings and/or adult plants with spores multiplied from the disease samples. Seedling tests are usually carried out under controlled environment conditions. Adult plant tests are carried out in the field, in Polythene tunnels or in controlled environment rooms. Results The United Kingdom Cereal Pathogen Virulence Survey Committee meets annually to discuss the scientific and agricultural significance of the results of virulence tests carried out during the previous year. The results are used to place wheat and barley cultivars in diversification groups on the basis of their specific resistances. The results of the virulence tests and the diversification schemes are published in the Annual Report. An explanation of terms used to describe resistance and virulence is also published in the report. Summaries of the following annual reports are available: Copies of the full reports and further information is available from the Secretary: Dr Rosemary A Bayles, or John Clarkson, National Institute of Agricultural Botany, Huntingdon Road, Cambridge CB3 0LE, UK. Price GBP 17.50 The information provided by the Survey is used in several ways. Isolates possessing new virulences are used by the National Institute of Agricultural Botany to evaluate the resistance of cereal cultivars in official trials and by plant breeders to select lines with effective forms of resistance. Isolates are also supplied to Universities and Colleges for research projects and teaching purposes. Versions of the cultivar diversification schemes, modified to meet regional requirements, are published by the National Institute of Agricultural Botany and the Scottish Agricultural College. The UKCPVS is funded by MAFF and H-GCA, with a contribution from breeders through fees charged for National List testing.
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