Title: Somaclonal variation in hybrid poplars for resistance to Septoria leaf spot

Author: Ostry, M.E.; Skilling, D. D.

Year: 1987

Publication: In: Guries, R. P., ed. Proceedings of the Fifth North Central Tree Improvement Conference. Madison, WI: University of Wisconsin-Madison: 89-100.

Abstract: Tissue culture techniques have been used to obtain hybrid poplars with putative resistance to leaf spot caused by Septoria musiva from clones previously susceptible to the disease. Stem internode explants were used to obtain proliferating callus cultures. Adventitious bud formation and shoot proliferation were then induced. Elongated shoots were excised and rooted in a peat : perlite medium under high humidity. After acclimation, rooted plants were transferred to the greenhouse. Variant plants were selected among the regenerants using a leaf disc bioassay that rapidly distinguishes plants with high resistance. The incidence of somaclonal variation in disease resistance differed among the genotypes tested. Over 500 tissue culture-derived plants tested for resistance using the bioassay have been planted in the field and are being evaluated for field performance. Somaclonal variation and tissue culture have the potential to significantly change tree breeding programs by reducing the time required for selecting and improving desired traits.