Multiple Resistance

In Western Europe around 75% of the beet growing area is infected and in the UK, the market share of rhizomania restraint varieties looks set to break the current 35% mark as growers start to make their decisions for 2009.

However, KWS’ aim is to introduce multiple resistance – or tolerance - into all its varieties – not just for rhizomania, but also cercospora leaf spot and beet cyst “It is a case of stacking resistances one on top of the other and ironing out any negatives that resistance to one characteristic may bring to another, particularly in terms of yield,” says Dr Günter Diener.

“While rhizomania resistance has been available for around 20 years, it is only in the last 3-4 years that associated penalties in terms of yield loss have been ironed out.”

This is clear to see in Carissima, which tops the 2009 UK Recommended List for yield and in another KWS stable mate Sophia that is just a couple of percentage points behind.

“We’ve been able to do this by constantly introducing what is largely one major resistant gene into a well established, high yielding breeding pool,” says Dr Diener.

While the stability of this gene and its protection against the rhizomania virus remains highly effective, Günter Diener suggests that the next step is to work with transgenics to provide an alternative mechanism of controlling the virus.