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Regeneration in Streptocarpus Leaf Discs and its Regulation by Temperature and Growth Substances
Author(s) -
APPELGREN MAIGULL,
HEIDE OLA M.
Publication year - 1972
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1972.tb03637.x
Subject(s) - auxin , cytokinin , biology , abscisic acid , botany , endogeny , limiting , regeneration (biology) , microbiology and biotechnology , biochemistry , mechanical engineering , gene , engineering
The formation of adventitious buds and roots in leaf discs of Streptocarpus x bybridus ‘Constant Nymph’ were both stimulated by relatively low temperatures (12 and 18°C) applied to isolated discs or to the growing plants before leaf harvest. Auxins also promoted both bud and root formation, the optimum concentration for rooting always being one to two orders of magnitude higher than the optimum for budding. Cytokinins had only a small stimulatory effect on bud formation. At higher concentrations it was inhibitory and even counteracted the stimulatory effect of auxin on bud formation. As usual, root formation was inhibited by cytokinin. GA 3 inhibited both bud and root formation but the inhibition was reversible by auxin. In presence of optimum auxin levels abscisic acid enhanced bud formation. It had little effect on root formation except for an inhibition at high concentrations. The effects of exogenous auxin and cytokinin suggest that Streptocarpus leaves have a high and non‐limiting level of endogenous cytokinin with auxin as the limiting factor for both root and bud formation. This would also explain the exceptionally high regeneration ability of this plant.