Screening Hybrid Poplars In Vitro for Resistance to Leaf Spot Caused by Septoria musiva. Michael E. Ostry, Principal Plant Pathologist, Forest Service, U. S. Department of Agriculture, North Central Forest Experiment Station, St. Paul, MN 55108. Ronald E. McRoberts, Kathleen T. Ward and Robert Resendez. Mathematical Statistician, Biological Technicians, Forest Service, U. S. Department of Agriculture, North Central Forest Experiment Station, St. Paul, MN 55108. Plant Dis. 72:497-499. Accepted for publication 21 January 1988. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1988. DOI: 10.1094/PD-72-0497.

An in vitro bioassay was developed to screen hybrid poplars (Populus spp.) for resistance to leaf spot caused by Septoria musiva. Leaf disks of clones inoculated with conidia of S. musiva displayed disease resistance similar to that found in field trials. This method shortens the time needed for evaluating the relative disease resistance of poplar clones.