Submitted to: Annual Beet Sugar Development Foundation Research Report
Publication Type: Other
Publication Acceptance Date: 5/26/2007
Publication Date: 6/15/2007
Citation: Kuykendall, L.D., Upchurch, R.G., Panella, L.W., Lewellen, R.T., Saunders, J.W. 2007. Cfp positive progeny from genetic crosses of elite germplasm with a transgenic sugar beet. Annual Beet Sugar Development Foundation Research Report. pp. E5-E12. Interpretive Summary: Cercospora leafspot is the most serious plant disease impacting U.S. sugarbeet production and profitability. This problem has been addressed by ARS scientists who discovered and then introduced a new gene called “CFP” specifically designed to confer disease resistance in sugarbeet. Produced by genetic transformation of a biotechnology clone, the new sugarbeet was then bred with selectively improved sugarbeet varieties in order to transfer the CFP gene into agronomically superior germplasm. Laboratory tests conducted on DNA samples from these new hybrid sugarbeets showed that some first-generation progeny from these crosses carry the CFP gene. The research plan now is to examine relative disease susceptibility among second-generation progeny, and the research results to be obtained may be useful to sugarbeet breeders in developing new varieties of leafspot resistance sugarbeets.
Technical Abstract: Resistance to Cercospora leaf spot disease, a serious problem for sugar beet production in most growing regions, has historically not been very amenable to genetic improvement by traditional means since only moderate resistance occurs naturally and it is multigenic with low heritability. Therefore, a biotechnological approach has been pursued in the MPPL at Beltsville, MD where we successfully introduced the cercosporin toxin export gene CFP from Cercospora into Beta vulgaris L using conjugation with a Rhizobium bacterium. CFP plants were crossed with genotypes C842 and 9933 developed in Salinas, CA. In 2006 progeny carrying the CFP gene were identified. The vernalization of all CFP positive individuals is currently being completed so that seed will be produced in 2007. This new generation is to be evaluated for resistance to Cercospora.