( ects of the pathogen and disease ?what ...)Sugar beet virus mutation requires Texas touch

"We started doing a lot of work with both of the viruses, and by default, I ended up with more experience than anyone else," he said. Strong genetic resistance to rhizomania was bred into sugar beet varieties and until 2002, that was effective, Rush said. But with only one gene selected for resistance, the plant virus mutated and overcame the resistant gene.

"We're going in now and looking at the molecular makeup of the plant virus," he said.

Making trips to the Imperial Valley in California and the Red River Valley growing region in Minnesota and North Dakota, Rush said his team works with growers and sugar company representatives at harvest time.

Soil samples and infected beets are brought back to the lab at Bushland. Sugar beets are planted in the contaminated soil and the virus is purified from the infected plants, he said. The virus isolate is cultured in test tubes, and the plants are no longer needed.

"We're trying to find out why this genetically mutated pathogen is able to overcome the resistance in the plant," he said. "We're looking at new crosses by seed companies and challenging them with each of these two viruses, as well as a combination of the two."

By measuring the effect of the disease on the plant, as well as purifying the virus and quantifying how much is actually present, they can determine if resistance is expressing itself, Rush said.

Breeders have good indications they may have some resistance in some wild relatives of sugar beets, he said. Advanced lines identified with potentially high levels of resistance will be planted in test plots in the sugar beet growing regions.

When these lines become available to producers and allow them to grow beets at a profit, that's when the research has come full circle, Rush said.