ISSN:
1365-3059
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Seventy-one isolates of Pseudocercosporella herpotrichoides, a non-random sample obtained from cereal crops in Britain between 1981 and 1983, were classified as either sensitive or resistant to 2 mg/l benomyl. In agar culture, isolates were of two distinct morphological types, described as ‘fast-even’ and ‘slow-feathery’. Pathogenicity to wheat and rye seedlings was determined for 21 fast-even and 32 slow-feathery isolates. Fast-even isolates were much more pathogenic to wheat than to rye; nearly all slow-feathery isolates were about equally pathogenic to wheat and rye. Thus, in morphology and pathogenicity, irrespective of sensitivity to benomyl, fast-even isolates conformed to the published descriptions of W-types, while slow-feathery isolates conformed to the descriptions of R-types.Sensitivity to 2 mg/l benomyl was determined for 97 isolates, including W-types and R-types, collected between 1956 and 1983, mainly from England but including some from nine other countries. Only 16 isolates were resistant; three were fast-even and 13 were slow-feathery. All were collected in England since 1981, suggesting that resistance has been rare until recently. Resistance was not a feature of R-type isolates collected before 1981. The increase in the proportion of resistant isolates since 1981 appears to have coincided with an increase in the proportion of R-type isolates.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-3059.1985.tb01375.x
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