Abstract: The present study describes, firstly, the effect of cultivar, photoenvironment and different abscisic acid (ABA) treatments on somatic embryogenesis in Brassica napus and secondly, describes the effects of ABA and drying rates on acquisition desiccation tolerance in cultivar Opera. In embryogenesis experiment, 20 days old cotyledon-derived calli were cultured in somatic embryo induction media with different concentrations of ABA (0, 0.5, 10 and 50 μM). These were incubated either in the dark or light. The calli were transferred to the same medium with either the same ABA or different ABA concentrations every 10 days. After 30 days the numbers of mature somatic embryos were counted. The results showed that light stimulated somatic embryo formation and maturation. Furthermore, differences in ABA response related to somatic embryogenesis were observed between cultivars. Also, embryos were likely more sensitive to ABA in days 1-10 and 21-30. For desiccation experiment, three ABA treatments were chosen from cultivar Opera. Then these embryos were cultured in germination medium without dehydration or dehydrated either with a fast dehydration rate or a slow dehydration rate before culturing in germination medium. The results showed that ABA treated embryos were more desiccation tolerant than non ABA treated embryos. It also showed that as the concentration of ABA increased, embryos tolerance to desiccation also increased. Moreover, slow drying rate was more beneficial for desiccation tolerance induction than fast drying in ABA treated embryos. In addition, ABA treated embryos had higher germination rates even when they were not dehydrated.