The effect of different hormone combinations on direct and indirect somatic embryogenesis in Agave americana

Direct and indirect somatic embryogenesis in Agave Americana through basal parts of micropropagated shoots were considered in this study. For micropropagation, 2 factors (BA and NAA) were utilized in different concentrations. A factorial experiment based on a completely randomized design (CRD) was accomplished with four replicates in a modified Murashige and Skoog medium (MSB). BA in 3 mg/L along with NAA in 0.1 mg/L was the best treatment for multiplication. Callus and embryo induction were evaluated using different auxins in a CRD experiment with three replicates in MS medium supplemented with L2 vitamins. Picloram 2.5 and 2 mg/L and also Dicamba 1 mg/L induced 66.7%, 60%, and 53.3% of explants to somatic embryo, respectively. Also, 2,4-D 2 mg/L had the highest impact on callus induction (95.6%). Embryogenesis was studied using Dicamba and Picloram in the same culture medium in a factorial experiment based on CRD with three replicates. The results of orthogonal polynomial analaysisindicated that high concentrations of Dicamba from 0 to 1.5 mg/L had a significant effect on somatic embryo induction. However, higher concentrations had the opposite effect on somatic embryo numbers. Germination of somatic embryos was performed in MSB medium without growth regulators.