Grg. Clover et al., Preliminary investigations of an uncharacterized virus of winter wheat (Triticum aestivum L.) in England, Z PFLANZENK, 106(3), 1999, pp. 275-283
Citations number
27
Categorie Soggetti
Plant Sciences
Journal title
ZEITSCHRIFT FUR PFLANZENKRANKHEITEN UND PFLANZENSCHUTZ-JOURNAL OF PLANT DISEASES AND PROTECTION
In 1995 and each subsequent year, the symptoms of an unrecognized disease h
ave been recorded in a crop of winter wheat (cv. 'Riband') in Bedfordshire,
England. Leaves of affected plants initially show faint mosaic symptoms wh
ich appear in April and develop into a more extensive chlorotic streaking d
uring May and June. The disease appears to be restricted to discrete areas
in the field which have changed little in size or position. Measurements ma
de by comparing diseased and symptomless plants in 1996 showed that the yie
ld of affected plants was reduced by 24 %. Electron microscopy revealed tha
t the disease symptoms are associated with the presence of a rod-shaped vir
us which resembles soilborne wheat mosaic virus (BWMV). The particles are 1
8-20 nm in width and have modal lengths of 100, 220 or 300 nm suggesting th
at the virus is multipartite. The vector of the disease is unknown but the
virus can be transmitted in air-dried soil suggesting that a fungal vector
may be involved. Also in common with SBWMV, the virus can be transmitted by
seed and is nor readily transmitted mechanically. Despite these similariti
es, extensive tests using seven different serological assays which detect a
ll reported SBWMV isolates did not unequivocally identify this virus. Simil
arly, RT-PCR using primers developed against both RNA 1 and 2 of the type s
train of SBWMV did not amplify the expected product. However, the unidentif
ied virus does not resemble any other known virus of wheat and therefore it
is thought that it represents either an unreported. strain of SBWMV or a n
ew wheat virus.