Effects of paclobutrazol and chlormequat on growth pattern and shoot proliferation of normal and variant aechmea faciata baker plant regenerated in vitro

In vitro propagated Aechmea facíala (clones Hip and Bayes) shoot tips regenerated profusely, but exhibited a high incidence (up to 20%) of variant plants. Some of the variation could be observed in vitro. However, after transplanting, the variant somaclones differed significantly, both morphologically and physiologically, from the parent plants. Aechmea variant somaclones are characterized by the development of several leaves on an elongated stem, assuming a grass-like appearance. The leaves are smaller than those of normal plants, non-waxy, and lack thorns and anthocyanin pigmentation. The growth regulators chlormequat ((2-chloroethyl) trimethyl ammonium chloride) and paclobutrazol (2RS, 3RS)- 1 -(chlorophenyl)-4, 4-dimethyl-2- (1 H-l, 2, 4-triazol-l-yl)pentane-ol) retarded normal and variant plants’ growth, and changed their leaf number and size. Paclobutrazol induced waxy leaf formation and promoted a massive development of adventitious buds on Aechmea variant somaclones transplanted to the greenhouse.