Variations in cryotolerance of embryogenic Picea abies cell lines and the association to genetic, morphological, and physiological factors

Two sets, containing 9 and 72 embryogenic cell lines of Picea abies (L.) Karst., were tested for cryotolerance using a standard two-step cryopreservation protocol. Eight and 69 cell lines, respectively, survived freezing in all or some of the trials. A strong effect of cell line on regrowth after freezing was demonstrated in both sets. Culture morphology and maturation competence of the nine cell lines was unaffected by freezing and were not correlated to cryotolerance. In the 72 cell lines originating from seeds of five full-sib families, selected from a progeny test for their widely different autumn frost hardiness, a family effect on cryotolerance was observed. This effect was not related to physiological characters (ability to form embryogenic cultures and mature somatic embryos, autumn frost hardiness)