Liquid Culture Systems for in vitro Plant Propagation

Mass propagation of conifer trees 393
For germination, good quality cotyledonary embryos were selected
individually (as looking similar to zygotic embryos) by hand from
development medium under a stereo microscope. After cold treatment,
selected embryos were transferred onto semi-solid medium for germination.
Culture plates were incubated for the first 5-7 days in the dark followed by
transfer to light. Percentage germination varied considerably among
genotypes. Germinated embryos (Figure 2) bearing an epicotyl were then
selected by hand and transplanted into 10 cubic inch Supercell pots
containing a mixture of peat, vermiculite and perlite, and incubated in the
greenhouse with frequent misting for acclimatization and growth. After
establishment in soil, somatic seedlings were transplanted to Weyerhaeuser
forest regeneration sites (Figure 3).
Figure 1: Somatic embryos of Douglas-fir from liquid medium.
Figure 2: Germinating somatic embryos on semi-solid medium.