MICROPROPAGATION OF CAMPANULA-ISOPHYLLA MORETTI

A method for micropropagation of Campanula isophylla Moretti is described. The method is based on division of the basal parts of shoot clusters into sections, each with four 3 mm stem stubs. Shoots from the shoot clusters are easy to root and give plants without apparent phenotypic aberrations. It is thus possible to propagate the stock and produce rooted plantlets in the same process. Basal sections of shoot clusters formed more shoots than shoot tips or single nodes. The medium used for propagation was MS with 4.4-mu-M benzyladenine (BA). Addition of naphthaleneacetic acid or raising the concentration of BA did not improve the results significantly. As primary explants 2 mm stem segments with an axillary or apical bud were used; smaller explants often failed to grow. For rooting the concentration of macronutrients was reduced to one-half, and BA was omitted. The cultures received an irradiance of 20-mu-mol m-2 s-1 fluorescent light; dry weight of shoots decreased if the irradiance was reduced. The method was used for propagation of 113 genotypes; shoot numbers and days to first root differed significantly among genotypes.