Micropropagation of Douglas-fir in a Double-phase Culture Medium

Speaker: Leah Gross

Abstract: The timber and Christmas tree industries are important components of the Pacific Northwest economy. A goal of both industries is to produce high quality trees at high growth rates. This requires increased genetic quality of the trees grown. Tissue culture provides the most promise to propagate these better genotypes. Douglas-fir has been tissue cultured previously, however, multiplication rates were low and success with mature material was limited. Recent research found that a double-phase system significantly increases multiplication rates of fruit and nut trees. A double-phase system of tissue culture consists of the conventional solid layer with the addition of a top liquid layer. Therefore, the objective of this study is to test a double-phase system on micropropagation of Douglas-fir, particularly mature clones. Preliminary experiments were performed on juvenile Douglas-fir to test media and media components while waiting to obtain mature material. Preliminary experiments concluded that 1) Dunstan B-2 medium provides better multiplication rates compared to SEM medium, 2) activated charcoal is a beneficial addition to the medium, and 3) a low hormone liquid phase may be superior to high hormone liquid phase and to no liquid phase. Final results of several experiments have yet to be obtained.
Leah Gross