Evaluación de protocolos para el establecimiento in vitro de cacao (Theobroma cacao L.)

Abstract

Theobroma cacao L. is a specie known for its economic importance in Ecuador, as it is one of the main agricultural products for export. For this reason, its cultivation continues to grow; however, its propagation faces phytosanitary problems due to the presence of diseases such as frosty pod rot (Moniliophthora roreri) and witch's broom (Moniliophthora perniciosa), which lead to large losses of up to 80% in production. Therefore, in vitro cultivation is presented as a solution for mass production of healthy plants. This research was divided into two complementary phases: In the first phase, a systematic review was conducted, and eight articles from the last ten years were selected based on inclusion and exclusion criteria. For the writing, information on the disinfection protocol was analysed, with four authors using compounds such as sodium hypochlorite and fungicides (azoxystrobin); while for cultivation, two authors suggest the addition of growth regulators to obtain a morphogenetic response. The second phase was carried out in the laboratory, where the best treatments found in the literature review on explants, buds, staminodes, and seeds were evaluated. For the disinfection protocol, two concentrations of NaClO (1,5 and 5%) and azoxystrobin (0,2 and 0,4%) were evaluated in bud and staminode explants, where 100% fungal contamination and mortality were found. Seeds showed 100% germination, but also 100% bacterial contamination. A directly proportional relationship was also found between the number of roots and stem length. In the evaluation of growth regulators, 2,4-D (2,2 ppm) and kinetin (1 ppm) were studied. In the explants of buds and staminodes, 100% fungal contamination and mortality were found. In seeds, 100% germination was observed despite 100% bacterial contamination.