Somaclonal Variation During Picea abies and P. omorika Somatic Embryogenesis and Cryopreservation

Abstract Embryogenic cultures of plants are exposed to various stress factors bothin vitroand 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 ofPicea abies(L.) Karst. andP. omorika(Pančić) Purk. maintainedin vitroor stored in liquid nitrogen by the pregrowth-dehydration method. The analysis of genetic conformity with using microsatellite markers was performed on cotyledonary somatic embryos (CSE), germinating somatic embryos (GSE) and somatic seedlings (SS), obtained from tissues maintainedin vitroor from recovered embryogenic tissues (ETc) and CSE obtained after cryopreservation. The analysis revealed changes in the DNA of somatic embryogenesis-derived plant material of bothPiceaspp. They were found in plant material from 8 out of 10 tested embryogenic lines ofP. abiesand in 10 out of 19 embryogenic lines ofP. omorikaafterin vitroculture. Changes were also detected in plant material obtained after cryopreservation. Somaclonal variation was observed in ETc and CSE ofP. omorikaand at ETv stage ofP. 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.