Tuesday, November 6, 2007
170-5

Identification of Mutations in Poa annua Alpha-Tubulin Conferring Resistance to Dinitroanilines.

Matthew Cutulle1, J. Scott McElroy2, C. Neal Stewart1, and Joshua S. Yuan1. (1) University of Tennessee, University of Tennessee, 2431 Joe Johnson Drive, Knoxville, TN 37996, (2) 2431 Joe Johnson Drive, University of Tennessee, University of Tennessee/ Turfgrass Weed Science, 252 Ellington Plant Science Building, Knoxville, TN 37996-4561

 Dinitroaniline herbicide resistant annual bluegrass (Poa annua L.) has been reported in North Carolina due to the repeated use of prodiamine in golf course fairways.  However, in Tennessee there have been no reported cases of annual bluegrass resistance to any dinitroaniline herbicides.  Reduced preemergence control of annual bluegrass with prodiamine was reported at Eagles Bluff Golf Course in Chattanooga, Tenn. Bioassays have previously been used to evaluate resistance to dinitroanilines; however they require mature seed and are very labor intensive.  Nucleic acid based screens do not require living tissue and the diagnosis time is short.  A single base pair mutation in the α-tubulin gene has been shown to confer resistance to dinitroanilines in multiple weeds.  α-tubulin genomic DNA from the Chattanooga population and  sensitive control was sequenced. Primers were designed complementary  to the mutation causing resistance.  Polymerse Chain Reaction (PCR) was utilized to amplify DNA containing the mutation. PCR products were run on an agarose gel and the presence of a distinct DNA band confirms resistance.