Effect of Bead Composition, PVS Type, and Recovery Medium in Cryopreservation of Bleeding Heart 'Valentine'-Preliminary Study

Bleeding heart (Lamprocapnos spectabilis (L.) Fukuhara) is a valuable ornamental and medicinal perennial. To date, there are few studies focused on cryopreservation of this species, although it could be useful in storage and breeding. This research is aimed at analyzing the effect of bead composition, type of plant vitrification solution (PVS), and the recovery medium of cryopreservation of bleeding heart. Shoot tips of L. spectabilis `Valentine' were used in the study. The explants were precultured on modified Murashige and Skoog medium (MS; 1962), supplemented with 9% sucrose, 1.0-mg.L-1 kinetin (KIN), and 2.62-mg.L-1 abscisic acid. Next, in the first experiment, the shoot tips were embedded in 3% calcium alginate, based either on an MS medium or distilled sterile water. The produced synseeds were inoculated on the recovery medium with 3.0-mg.L-1 KIN, 0.5-mg.L-1 6-benzyladenine (BA), or cytokinin-free control. Based on the results of the first study, in the second experiment, precultured shoot tips were embedded in 3% calcium alginate based on MS medium and dehydrated with PVS2 or PVS3 for various durations. The pre-treated explants were plunged in liquid nitrogen and, after rewarming, inoculated on the recovery MS medium with 0.5-mg.L-1 BA. PVS3 was more effective in securing the shoot tips than PVS2. The highest recovery level (68.3%) was reported after a 150-min pretreatment with PVS3. Explants from this experimental combination also proliferated the highest number of shoots, as well as those with the greatest length. On the other hand, a higher share of dry weight was found in PVS2-derived shoots (13.5-18.2%) compared with plants produced after PVS3 treatment (10.6-11.4%). The obtained results here can serve as a good basis for further studies related to synthetic seeds and cryopreservation of bleeding heart.