Resterilization in Cocoa (Theobroma Cacao L.) Somatic Embryogenesispropagation to Save Contaminated Embryos

Somatic embryogenesis is a technique to produce primary embryos using tissue culture. Contamination in tissue culture can be caused by internal and external contaminant. Resterilization can be performed to save contaminated embryos. The aim of this research is to obtain resterilization method in cocoa micropropagation by tissue culture so that free bacterial explants can be obtained and embryogenic. This experiments used five clones of cocoa, namely Sulawesi 1, KW 514, ICCRI 05, ICCRI 03 and ICCRI 04. Embryogenic clusters in multiplication medium were used as explant. Sodium hypochloride was used as sterilant. Several factors were evaluated using randomized block complete design, i.e. contaminant level, concentration of sterilant and period of sterilant application. Results of resterilization methods showed no significant effect among several factors tested. Among those factors, low contamination level, 10% concentra tion of sterilant and no soaking showed the highest percentage of saving of contaminated embryos. There was different response among five cocoa clones in producing embryogenic explants when using combination of resterilization methods

The Effect of 2,4 Dichlorophenoxyacetic Acid on in Vitro Callogenesis of Cocoa (Theobroma Cacao L.)

Cocoa (Theobroma cacao L.) development using modern breeding techniques can be facilitated by propagation of planting material through somatic embryogenesis. Various factors that may affect embryogenesis are the composition of culture medium and culture condition. Hormone commonly used to initiate the formation of callus is auxin with type 2.4-D (2.4 Dichlorophenoxy acetic acid). The aim of this study was to determine the effect of the addition of 2.4 -D hormoneson the process of cocoa embryogenesis. The treatments were arragged in factorial combination in completely randomized design, which consisted of two factors. Thefirst factor was the concentration of auxin 2,4-D 25 %, 50 %, 75 %, and 100 %; and the second factor was cocoa clones; Sulawesi 01 and Sulawesi 02. The resultshowed that the addition of 2.4-D hormone up to 100% on somatic embryogenesis of cocoa for Sulawesi 01 clone was not significantly different from Sulawesi 02 clone for all parameters. While on the addition of 2.4-D, there was significant difference between Sulawesi 01 and 02. Cocoa embryogenic callus using the addition of 2.4-D (25%-100%) was significantly different from control. Increased concentrations of 2,4-D hormone which is applied onto media would inhibit the formation of the somatic embryo. Addition of 2.4 D 25%, encouraged towards non-embryogenic callus