Callus-Mediated Plant Regeneration from Morphologically Changed Petals Produced by Mutagen-Treated Apical Rose Buds

摘要

The apical buds of lateral rose branches (Rosa hybrida ‘Carl Red’) were asexually propagated by cutting and treatment with chemical mutagens (N-methyl-N’-nitro-N-nitrosoguanidine, ethyl methane sulfonate, 6-azacytidine, and acridine orange), and the growth and differentiation or morphological alterations of the mutagen-treated buds were traced in developed flowers. Variations in size, shape, colour, and the number of petals were detected most frequently in flowers produced from apical buds treatedwith 100 jig/ml N-methyl-N’-nitro-N-nitrosoguanidine. The variant petals were cultured on Murashige and Skoog medium supplemented with a-naphthalene acetic acid and 6-benzylaminopurine for in vitro isolation and the reproduction of morphologically altered rose plants. Embryogenic calli were obtained from adventitious roots induced from the petals and were successfully differentiated into intact plants. Consequently, the regenerated plants produced flowers that were different from those originally usedfor tissue culture. The appearance of the flowers in these rose plants was highly consistent through repeated cycles of cutting, suggesting that the present approach is an easy and rapid procedure for mutation breeding in rose in combination with tissueculture techniques for the in situ isolation and propagation of variant plants. This approach is expected to provide an effective method for easily and rapidly inducing variations in rose flowers and for in vitro morphogenesis through their regeneration.