Effects of autoclaving on the physiological action of paclobutrazol

Abstract

Besides being employed as an efficient plant growth retardant for field, garden and potted plants, paclobutrazol (PBZ) is also used in labo-ratory experiments, mainly in aseptic cultures, both in autoclaved and non-autoclaved form. Therefore it is not known if autoclaving can par-tial or completely inactivate the product, thus decreasing its efficacy. Thus a simple experi-ment was carried out to assess to what extent the autoclaving process can affect some growth components and dry mass accumulation and partition in sunflower seedlings, by employing the techniques of Plant Growth Analysis. Auto-claving did not modify either qualitative or quantitatively any of the plant responses to PBZ as well their reversions by gibberellic acid.