EFFECT OF HORMONES AND VITAMIN B12 ON GAMETOPHORE DEVELOPMENT IN THE MOSS PYLAISIELLA SELWYNII |
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Authors: | Luretta D Spiess Barbara B Lippincott James A Lippincott |
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Institution: | Department of Biology, Lake Forest College, Lake Forest, Illinois, 60045
Department of Biological Sciences, Northwestern University, Evanston, Illinois, 60201 |
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Abstract: | Bud formation in the moss Pylaisiella selwynii is greatly enhanced by cytokinins at concentrations as low as 10−12m , yet these buds usually fail to develop into normal gametophores. Various ratios at different concentrations of the cytokinin N-6-γ,γ-dimethylallylaminopurine to indoleacetic acid failed to enhance bud initiation over that obtained with cytokinin alone or to permit normal gametophore development. Deletion of the cobaltous ions from the culture medium prevented the appearance of the few gametophores usually formed in the complete medium, but different amounts of cobaltous ion did not significantly enhance initiation of gametophore development. Bud initiation was enhanced 3- to 20-fold by vitamin B12 at 10−5m or by B12 coenzyme at 10−4m , and the time of appearance of these buds was advanced by 6–12 days compared to control plants. At these concentrations of the B12 compounds the buds formed normal gametophores, but at 10−4m vitamin B12 they grew into callus-like masses similar to those obtained with cytokinins. Although the effects of B12 on bud initiation and development mimicked those of cytokinins, except in permitting normal development, no additive or synergistic effects were observed when they were tested together. It is suggested that B12 may play a regulatory role in the control of gametophore initiation and development in mosses. |
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