ESTATE CROPS INFO – The secondary somatic embryogenesis of coffee plant can be used to propagate superior varieties, plant resulted from genetic transformation and mutation. Present study aimed to obtain the best media composition for induction of secondary somatic embryos in solid or semi-solid media, and to evaluate the possibility of somaclonal variations occurrence in the resulting plantlets. Primary somatic embryos torpedo phase of the AS2K variety were used as explant sources. Types of cytokines i.e. 2-iP (4.54 and 9.08 μM), kinetin (9.30 μM) and BAP (BAP 17.76 and 1.33 μM) and medium density (solids and semi-solid) were used as treatments. A total of 20 SSRs marker were used in molecular analysis of plantlets with 10 replication per treatment. The results showed that the media with the addition of BAP 17.76 μM resulted in the highest percentage (75.50%), the highest number of secondary somatic embryos (10.63), the tertiary, quarter and quiner somatic embryos. Number of secondary somatic embryos produced in a dense media was higher than those in the semi-solid media.. Based on molecular analysis, planlets on all treatment were relatively homogenous except on medium with 17.76 μM BAP which indicated by one allelle changing at ssrR209 locus. These findings indicated that the use of culture medium with supplemented with 9.08 μM 2-iP is advisable to induce the secondary somatic embryos due to its capacity to produce high number of somatic embryos and exhibited no somaclonal variations occurred among the plantlets.
Keywords: Coffea arabica, tertiary somatic embryos, quarter somatic embryos, quiner somatic embryos, semi solid media