MICROPROPAGACIÓN DE CHAYOTE (Sechium edule Jacq. SW.) AP ARTIR DE BROTES VEGETATIVOS 1

Micropropagation of waterpear (Sechium edule Jacq. S.W.) from vegetative shoots. Waterpear (Sechium edule) is an important source of revenue for the exporting countries, being Costa Rica the leading producer. Among the main limiting factors for its production are the planting materials, traditionally the seed, that because of its nature it does not allow the production of morphologically homogeneous fruits (color, shape and epidermal texture), which results in high percentages of rejected fruits at the packing plant. The establishment of a protocol for vegetative propagation of this species will help to solve the heterogeneity problems. The present research was directed to develop a micropropagation protocol from shoots. The effect of various desinfectants and concentration of growth regulators during the in vitro establishment, multiplication and rooting phases were evaluated. Desinfections with 4% calcium hypochlorite allowed the highest percentage of aseptically established explants under in vitro conditions. There was also observed that during the following phases of micropropagation the requirements of growth regulators were very low (0.1 mgL-1 BA during bud sprouting and 0.1 to 0.2 mgL-1 AIB during rooting) or were not required (microcutting multiplication).