Cell suspensions of Daucus carota and Haplopappus graciiis and callus suspensions of Allum cepa var. proliferum were grown in media with and without activated charcoal. Differentiation occurred in those Daucus and A Ilium cultures that contained charcoal. It was shown by mass spectrometry that the media without charcoal contained high amounts of phenylacetic acid and /i-OH-benzoic acid {Daucus), 2,6-OH-benzoic acid {Allium) and benzoic acid, pelargonic acid and caprylic acid {Haplopappus), whereas the media with activated charcoal did not. It was also shown that p-OH-benzoic acid had inhibitory effects on the embryogenesis in Daucus cultures.

No abstract

Isolated embryos of Pinus contorta Dougl. ex Loud, were induced to form adventitious buds on a cytokinin-supplemented medium. Further development of the buds required transfer to a cytokininless medium. Both bud induction and development were stimulated by a dilution of the basal culture medium and best growth was obtained if the buds were isolated from the original tissue when stem elongation had started. The growth of these isolated adventitious shoots was further stimulated by adding activated charcoal to the diluted medium. A small percentage of the shoots have been rooted. The capacity for bud formation varied among seeds collected from different regions of British Columbia. This method for induction of adventitious buds on embryos was also applicable to explants of young seedlings.

No abstract

The effects of activated charcoal on growth and morphogenesis in plate cultures of different plant cells have been studied. It was shown that medium containing charcoal induced embryogenesis in cultures of Daucus carota in which embryo formation could not be brought about by omitting auxin from the medium. Charcoal‐medium also induced abundant root formation in older cultures of Allium cepa, which normally did not produce roots. The growth of cultures of Glycine max and Haplopappus gracilis was totally inhibited by charcoal. It is thought that activated charcoal removes substances from the medium, one of which might be auxin.