Nesterova et al. Genome cryoconservation of Russian Far East plants by seeds, spores and pollen frozen in liquid nitrogen

Genome cryoconservation of Russian Far East plants by seeds, spores and pollen frozen in liquid nitrogen

Svetlana V. NESTEROVA¹, Irina B. KRESHCHENOK² & Irina N. KRESTOVA¹
¹ Botanical Garden-Institute FEB RAS, Vladivostok, Russia
² Amur Branch of Botanical Garden-Institute FEB RAS, Blagoveshchensk, Russia

Long-term storage gene banks are a promising ex situway to preserve the wealth of natural flora diversity. We investigated the possibility of cryopreservation using liquid nitrogen (-196°C) for seeds, spores and pollen. The seeds of the species studied retained their viability after thawing. However, a differential response of seeds to deep freezing was detected. Statistical analysis did not reveal changes in seed germination of species from the genera Agastache, Artemisia, Deutzia, Hypericum, Potentilla, Pinus, Papaver, Primula, Rabdosia, Thymus, Weigela. Seed germination of Ampelopsis and Celastrus species increased by 15-20 %. Saxifraga and Rhododendron seeds also responded positively. An increase in seed germination in Astragalus and Lespedeza could be explained by a decline in the proportion of hard seeds. Liquid nitrogen had a negative thermal effect on seeds in the genera Aristolochia, Armeniaca, Cerasus, and Microcerasus as indicated by a decrease in germination. Cryopreservation did not affect growth rate and development of plants when plants were grown from the frozen seeds. Although fern spores responded differently to freezing, in the majority of the species spore germination capacity remained unchanged after thawing. However, in some species we observed an increase in germination by 60-80 % and reduced spore germination by more than 40 %. It was revealed that the species of the same genus or family respond differently to spore freezing. Frozen pollen of Hemerocallis wild species and cultivars were used in the selection experiment with the cv. "Cork". When using thawed pollen of cv. "Regal Air" the number of ovules and seeds in the fruit increased. In the case of pollination with pollen cv. "Prairie Blue Eyes" seed germination also increased. Flowering plants were grown from the seeds obtained in these pollination experiments.