Multiple Bud Formation by Cultured Embryos of Pinus ponderosa

Excised embryos of Pinus ponderosa Dougl. ex Laws formed callus and initiated a few buds from the tips of the cotyledons when placed on the full-strength medium of Sommer et al. (1975) or Cheng (1975). When excised embryos were placed on a full or half strength dilution of the medium of Reilly and Washer (1977) or on a half strength dilution of Cheng (1975), buds were initiated along the entire length of those cotyledons which were in contact with the medium. Initiating buds along the entire length of the cotyledon increased the yield of excisable buds. Benzyladenine must be present in the media for bud initiation; however, the addition of auxin may increase the yield of excisable cotyledonary buds.