Effect of different disinfection methods on the in vitro establishment of cocoa (Theobroma cacao L.) at the Sapecho Experimental Station - Bolivia

Marco Antonio Echenique Quezada; Delcy Calle Alanoca

Abstract

Cocoa (Theobroma cacao L.) is a perennial tree grown in humid tropical areas, of great economic importance for Africa, Asia and Latin America, its production has been limited by the impact of diseases and the low productive potential of plantations. There are clones with high productive potential and tolerance to the main diseases, but there is no efficient method of plant propagation, so somatic embryogenesis is seen as a tool for the mass production of these clones. The work was carried out in the Plant Biotechnology Laboratory of the Sapecho Experimental Station, located in the municipality of Palos Blancos in the department of La Paz, with the aim of establishing in vitro, using explants from the flower buds of cocoa, using three methods disinfection. Fourteen days after starting the in vitro implantation, total contamination (fungi, bacteria) was evaluated. 21 days later, the surviving explants and callus formation were observed. As a result, it can be mentioned that the highest percentage of fungal and bacterial contamination was 98.5%, which was presented using method III independent of the type of explant used, the disinfection method with the highest survival rate was method I with 64% in staminodia and method II with 25% in cocoa petals, the highest percentage of callogenesis formation occurred with method I and method II using staminoids with 35% and 10% respectively. The type of explant used has a great influence on contamination, survival and callus formation, so it can be indicated that the type of explant that presents the best in vitro establishment of cocoa is staminodies, in order to obtain disease-free seedlings.