SOMACLONAL VARIATION DURING PICEA ABIES AND P-OMORIKA SOMATIC EMBRYOGENESIS AND CRYOPRESERVATION

Embryogenic cultures of plants are exposed to various stress factors both in vitro and during cryostorage. In order to safely include the plant material obtained by somatic embryogenesis in combination with cryopreservation for breeding programs, it is necessary to monitor its genetic stability. The aim of the present study was the assessment of somaclonal variation in plant material obtained from embryogenic cultures of Picea abies (L.) Karst. and P. omorika (Pancic) Purk. maintained in vitro or stored in liquid nitrogen by the pregrowth-dehydration method. The analysis of genetic confoimity with using microsatellite markers was performed on cotyledonary somatic embryos (CSE), germinating somatic embryos (GSE) and somatic seedlings (SS), obtained from tissues maintained in vitro or from recovered embryogenic tissues (ETc) and CSE obtained after cryopreservation. The analysis revealed changes in the DNA of somatic embryogenesis-derived plant material of both Picea spp. They were found in plant material from 8 out of 10 tested embryogenic lines of P abies and in 10 out of 19 embryogenic lines of P. omorika after in vitro culture. Changes were also detected in plant material obtained after cryopreservation. Somaclonal variation was observed in ETc and CSE of P omorika and at ETv stage of P abies. However, most of the changes were induced at the stage of somatic embryogenesis initiation. These results confirm the need for monitoring the genetic stability of plants obtained by somatic embryogenesis and after cryopreservation for both spruce species.