MICROPROPAGATION OF WESTERN WHITE-PINE (PINUS-MONTICOLA) STARTING WITH MATURE EMBRYOS

As part of a program to develop micropropagation protocols for western white pine, the production of adventitious shoots from mature embryos was investigated. Litvay's medium proved to be the best of the six me dia formulations tried. The optimum concentration of N6-benzyladenine was 30 mu M for 21 days. BiTek agar which had an optimum at 8 g/L prod uced significantly more shoots than GelGro gellan gum which had an opt imum at 5 g/L. There was no significant difference in the shoot produc tion between three different seed lots, two from interior British Colu mbia and one from coastal British Columbia, with this protocol. Harves ted adventitious shoots survived best on the medium of GresshofF and D oy at half-strength. Using the protocol described here, it was possibl e to obtain 500 to 600 shoots for every 100 embryos explanted. Up to 8 0 percent of the shoots continued to grow three months after excision from the explants.