Paclobutrazol on In Vitro Growth and Development of Zygopetalum crinitum Orchid, and on Seedling Acclimatization

In vitro cultivation is a technique that allows the production of great amount of plants. However, significant losses may occur during the acclimatization period (ex vitro stage). The objective of this study was to evaluate the effect of paclobutrazol, in the Murashige and Skoog culture medium, on growth, development, and survival of Zygopetalum crinitum plants. The experimental design (both in vitro and ex vitro) was completely randomized with four treatments: three paclobutrazol concentrations (0.5; 1.0; and 1.5 mg L-1 active ingredient) and the control (without PBZ). Morphological changes promoted by the paclobutrazol application were observed in the seedlings; however, it did not result in higher seedling survival rates of the Zygopetalum crinitum orchid.