The role of seeds and airborne inoculum in the initiation of leaf blotch (Rhynchosporium secalis) epidemics in winter barley

A - Papers appearing in refereed journals

Fountaine, J. M., Shaw, M. W., Ward, E. and Fraaije, B. A. 2010. The role of seeds and airborne inoculum in the initiation of leaf blotch (Rhynchosporium secalis) epidemics in winter barley. Plant Pathology. 59 (2), pp. 330-337.

AuthorsFountaine, J. M., Shaw, M. W., Ward, E. and Fraaije, B. A.
Abstract

Both airborne spores of Rhynchosporium secalis and seed infection have been implied as major sources of primary inoculum for barley leaf blotch (scald) epidemics in fields without previous history of barley cropping. However, little is known about their relative importance in the onset of disease. Results from both quantitative real-time PCR and visual assessments indicated that seed infection was the main source of inoculum in the field trial conducted in this study. Glasshouse studies established that the pathogen can be transmitted from infected seeds into roots, shoots and leaves without causing symptoms. Plants in the field trial remained symptomless for approximately four months before symptoms were observed in the crop. Covering the crop during part of the growing season was shown to prevent pathogen growth, despite the use of infected seed, indicating that changes in the physiological condition of the plant and/or environmental conditions may trigger disease development. However, once the disease appeared in the field it quickly became uniform throughout the cropping area. Only small amounts of R. secalis DNA were measured in 24 h spore-trap tape samples using PCR. Inoculum levels equivalent to spore concentrations between 30 and 60 spores per m 3 of air were only detected on three occasions during the growing season. The temporal pattern and level of detection of R. secalis DNA in spore tape samples indicated that airborne inoculum was limited and most likely represented rain-splashed conidia rather than putative ascospores.

KeywordsAgronomy; Plant Sciences
Year of Publication2010
JournalPlant Pathology
Journal citation59 (2), pp. 330-337
Digital Object Identifier (DOI)doi:10.1111/j.1365-3059.2009.02213.x
Open accessPublished as non-open access
FunderBiotechnology and Biological Sciences Research Council
Syngenta
Funder project or codeCentre for Sustainable Pest and Disease Management (PDM)
ISSN00320862
PublisherWiley

Permalink - https://repository.rothamsted.ac.uk/item/8q4xw/the-role-of-seeds-and-airborne-inoculum-in-the-initiation-of-leaf-blotch-rhynchosporium-secalis-epidemics-in-winter-barley

5 total views
0 total downloads
0 views this month
0 downloads this month