Tolerance of wheat varieties to Soil-borne Wheat Mosaic Virus (SBWMV)

Abstract

The discovery of soil-borne wheat mosaic virus (SBWMV) on a Wiltshire farm in 1999 triggered concern for the continuation of wheat production in the UK. Potential yield losses are high and the only practical method of control will be the use of resistant or partially resistant varieties. There was therefore an urgent need to:

•      compare the severity of SBWMV symptoms (confirmed by ELISA) in plots of wheat varieties grown on infected sites
•      identify UK varieties with resistance to SBWMV

Wheat varieties from the Recommended List (RL) and National List (NL) were sown on an infected site on the Wiltshire farm and assessed, both visually and by ELISA, to determine their susceptibility to the virus. 

Five varieties from the RL and provisional RL were resistant in the first year of testing with 29 varieties from the NL also being resistant. Approximately a third of the varieties tested had low levels of infection whilst just under a half of varieties were very susceptible. Currently, there are three resistant varieties on the Recommended List for 2002. These are Charger, Claire and Hereward. 

A further two infected sites were identified in Kent in 2000, but none was reported in 2001.

If SBWMV follows a similar pattern to the spread of BaYMV and BaMMV then we can expect the virus to be widespread throughout the UK by 2010.

The availability of resistant wheat varieties will not only maintain the viability of growing wheat on infected land but their use should also reduce the spread of infection. The evidence from this investigation and from countries already with widespread SBWMV would suggest that there is a sufficient gene pool to produce a number of resistant varieties suitable for the UK market. Routine testing as part of the Recommended List programme will keep levy payers abreast of new resistant varieties as they become available.