Our involvement with Rick Hall's poplar breeding program at ISU was on Melampsora rusts of poplars and Cryptosphaeria canker in Iowa. Unfortunately, the project, like many alternative energy projects, was terminated by the US-DOE in 2001.
Chen, W., and T. C. Harrington. 2006. Genetic diversity of poplar leaf rust populations in the north-central United States. Can. J. For. Res. 36:2047-2057. (download PDF file here).
Steimel, J., W. Chen, and T. C. Harrington. 2005. Development and characterization of microsatellite markers for the poplar rust fungi Melampsora medusae and M. larici-populina. Molecular Ecology Notes 5:484-486. (download PDF file here).
Szabo, I., and T. C. Harrington. 2004. First report of Thielaviopsis populi on hybrid poplar in Hungary. Plant Pathology 53:249.
Wei Chen. 2001. Population genetics of Melampsora medusae on poplar in Minnesota, Iowa and Missouri. M.S. Thesis, Iowa State University.