Somatic Variation in Resistance of Populus to Septoria musiva. M. E. Ostry, Research Plant Pathologists, North Central Forest Experiment Station, St. Paul, MN 55108. D. D. Skilling, Research Plant Pathologists, North Central Forest Experiment Station, St. Paul, MN 55108. Plant Dis. 72:724-727. Accepted for publication 25 March 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-72-0724.

Tissue culture of hybrid poplars previously susceptible to leaf spot caused by Septoria musiva was used to obtain poplars with putative resistance. Stem internode explants were used to obtain proliferating callus cultures on which adventitious bud formation and shoot proliferation were induced. Elongated shoots were excised and rooted in a peat-perlite medium under high humidity and transferred to the greenhouse. Variant plants were selected among the regenerants using a leaf disk bioassay that distinguished resistant plants. The incidence of somaclonal variation differed among genotypes. Tissue culture of poplars is potentially useful in detecting and recovering somaclonal variation in resistance to Septoria.

Keyword(s): disease, tree improvement.