Award details

Characterisation and diagnosis of fungally-transmitted viruses of cereals and their vectors

Reference	BBS/E/C/00000187
Principal Investigator / Supervisor	Professor Michael John Adams
Co-Investigators / Co-Supervisors
Institution	Rothamsted Research
Department	Rothamsted Research Department
Funding type	Research
Value (£)	244,340
Status	Completed
Type	Institute Project
Start date	01/04/1997
End date	31/03/1999
Duration	24 months

Abstract

There are several fungally-transmitted viruses of major importance to cereal crops, including barley yellow mosaic bymovirus (BaYMV), barley mild mosaic bymovirus (BaMMV), oat mosaic bymovirus (OMV), oat golden stripe furovirus (OGSV), wheat spindle streak mosaic bymovirus (WSSMV) and soil-borne wheat mosaic furovirus (SBWMV). These are apparently all transmitted by the obligate root infecting fungus, Polymyxa graminis. This fungus is classified in the Plamsodiophorales, a group of parasites that may have more affinities with protozoa or algae than with the more well- known fungi. This project aims to study the fundamental properties of the viruses, including genome characterisation, and to develop sensitive diagnostic methods. These studies will include nucleic acid sequencing of selected viruses (or portions of their genomes), production of antisera and the development of detection methods based on the polymerase chain reaction (PCR). 2 Virus isolates from different sites in the UK will be examined to determine the distribution of BaMMV and BaYMV on different cultivars and in different regions. It also aims to characterise the fungus vector, by examining its basic biology, determining biological differences between isolates and relating these to studies of the fungus genome. Fungus isolates will be grown on plant roots in sand culture and used to investigate the host range of different isolates. Factors affecting the efficacy of zoospore infection (and thus of virus transmission) will be investigated, including studies of the susceptibility of different parts of the root system and the possible role of attractants (chemotaxis). Electron microscopy will be used to study the fungus life-cycle and to assist studies on the basis of virus transmission. 3 Studies of ribosomal DNA (rDNA) from fungus isolates will be used in restriction fragment length polymorphism (RFLP) analysis to examine variation amonst isolates and portions of rDNA will be sequenced to determine the relatedness of isolates to one another and to other lower fungi of importance (e.g. Polymyxa betae, the vector of beet necrotic yellow vein furovirus, the cause of rhizomania of sugar beet). Microscopic and molecular comparisons will also be made with some less well known but related fungi, including Ligniera spp., that can be found in cereal roots. To begin sequencing oat mosaic virus. To test infected samples from different parts of the UK for the presence of the barley mosaic viruses. To examine factors affecting the efficacy of zoospore infection (and thus of virus transmission), including studies of the susceptibility of different parts of the root system and the possible role of attractants (chemotaxis). To develop improved bait plant methods for soil-borne wheat viruses by (1) designing PCR protocols to give increased sensitivity and (2) studying factors which stimulate germination of resting spores with a view to synchronizing and standardizing zoospore release and subsequent infection.

Summary

unavailable

Committee	Closed Committee - Agri-food (AF)
Research Topics	X – not assigned to a current Research Topic
Research Priority	X – Research Priority information not available
Research Initiative	X - not in an Initiative
Funding Scheme	X – not Funded via a specific Funding Scheme

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