|Boore, Jeffrey - DOE JOINT GENOME INSTIT.|
|Neelam, Beena - NATIONAL CANCER INSTITUTE|
|Stephens, Robert - NATIONAL CANCER INSTITUTE|
Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: May 1, 2007
Publication Date: August 1, 2007
Citation: Anderson, S.J., Stone, C.L., Boore, J.L., Neelam, B.A., Stephens, R.M., Luster, D.G., Frederick, R.D., Pedley, K.F. 2007. Phenotypic and genetic variation among soybean rust isolates. Phytopathology. 97:S4 Technical Abstract: Phakopsora pachyrhizi, the causal agent of soybean rust, is an aggressive foliar disease that is found in all major soybean growing regions. The discovery of soybean rust in production fields in the southeastern U. S. in 2004 and its spread to other areas in subsequent years has heightened concerns that the disease could become a major threat to the U. S. soybean crop. Its arrival in the U. S. has also raised many questions as to the source of the U. S. isolates, and the genetic diversity among isolates of the pathogen in the U. S. and other parts of the world. As a first step towards addressing these questions we have mined the genomic sequences deposited in GenBank for microsatellites. Twenty-four of the microsatellites discovered were used to survey 28 isolates of P. pachyrhizi collected from the U. S. and abroad. Nineteen of these microsatellite markers were useful for assessing genetic variation among the isolates. Based on this analysis we demonstrate that the six P. pachyrhizi isolates collected from Louisiana and Alabama in November 2004, are genetically diverse. These six U.S. isolates also showed different reaction phenotypes when inoculated onto soybean accessions containing the four rust resistance genes Rpp1-4.