IPPRAS Cryobank for the Conservation of Orthodox Seeds of Rare, Endangered, Medicinal, and Ornamental Plant Species—Current Research

Abstract

Plant cryobanks play a significant role in modern science and breeding. They contribute to the recovery of lost species, the emergence of new plant varieties, and help preserve and explore the diversity of the plant world. The IPPRAS Cryobank collection is constantly supplemented with new samples, while, at the same time, the stored samples are being monitored. In order to test seed germination, seeds of Allium and Veratrum species were thawed. Rare Allium species seeds, such as A. nutans, A. schoenoprasum, and A. victorialis were stored in liquid nitrogen for 17, 19, and 30 years, respectively. Long-term cryopreservation decreased germination rates for A. nutans from 96.55 to 50.00%, for A. schoenoprasum from 72.00 to 62.75%, and for A. victorialis from 90.00 to 83.05%. Seeds of a rare medicinal species, Veratrum lobelianum, were stored in liquid nitrogen for 18 years; the seed germination rate during this storage period has been significantly decreased from 75.00 to 14.81%. V. nigrum seeds were also collected and frozen in liquid nitrogen for 3 days. Short-term cryopreservation did not result in a statistically significant change in germination rates (from 79.71 to 82.69%). The seeds of an endangered ornamental species, Cypripedium calceolus, were collected and kept frozen for 3 days. After cryopreservation, the seeds were planted on three different media, as follows: ½ MS, MS with 10% coconut milk, and BM1. On ½ MS medium, 24.98% seeds formed protocorms, while on MS medium with 10% coconut milk, this number was 10.02%, and on BM1 medium, it was 15.02%, respectively; however, after 2.5 months, all of the protocorms died. Thus, it appears that the existing protocol for seed cryopreservation of C. calceolus needs further improvement. The size, weight, and free water content (WC) of six previously cryopreserved Stipa species and three Allium species were measured. For all the Allium and Stipa species studied, we found no correlation between seed size, WC, and cryotolerance. We also found no correlation between the life form, which reflects the water requirement of the species, and cryotolerance.