Chrysanthemum under ice spell
‘Cryopreservation of chrysanthemums using encapsulation-dehydration’
Dariusz Kulus1, Anna Mikuła2 – authors of photographs,
Małgorzata Zalewska1 – project manager
11University of Technology and Life Sciences in Bydgoszcz, Faculty of Agriculture and Biotechnology,
Department of Ornamental Plants and Vegetable Crops – Laboratory of Biotechnology,
Bernardyńska 6, 85-029 Bydgoszcz
2Polish Academy of Sciences, Botanical Garden – Center for Biological Diversity Conservation,
Prawdziwka 2, 02-973 Warszawa,
Smurfy apex – shoot tip shown in ultraviolet light
“The Milky Way” – vascular bundle viewed with fluorescence microscope
Greater than pearls – shoot tips encapsulated in protective, alginate
Description popularizing the research project
Out of all chrysanthemums, the best-preserved ones are the flowers that were immortalized in songs and poems. They have lasted unchanged for decades, untouched by turbulent times and wars. They radiate with beauty and strength every time the song is played, the poem is read. When the last verse fades, they fall into a slumber until somebody wakes them up again evoking distant romantic memories.
Chrysanthemums are just perfect for hibernating and reanimating them. They appear in late summer or autumn when most of other flowers have already faded leaving just their seeds or dried bouquets. Among the few flowers available then, chrysanthemums are unique with their long blossom, resistance and plethora of varieties, colours and forms. There are still new ones: more interesting, more colourful, more resistant to pests and infections, and easier in breeding. Yet today although the new flowers seem to be a work of art, poets do not create them. They are born in biotechnological laboratories, where the desired effects are obtained through genetic engineering. Yet to preserve and awake the precious beauties even the most sublime poetry is helpless. Instead of that, or apart from that, the carefully prepared delicate buds are frozen at the temperature of nearly minus 200 °C. Although the chrysanthemums preserved with low temperatures do not last as long as the ones described in poetry, cryopreservation is an efficient method of storing the buds. Protected with capsules and immersed in liquid nitrogen they have a chance to survive, and more than half of them can turn into the beautiful and sentimental flowers. Surely, they will enchant new generations of poets and they, in turn, will preserve them in the next poem.
Thanks to their great variety, aesthetic value, cultural meaning and wide practical use, chrysanthemums are one of the most popular plants, cultivated all over the world. Every year, new varieties are introduced to the market, replacing the current assortment. Nowadays it is important to elaborate a strategy for conservation of valuable genetic material for the purpose of breeding. Cryopreservation is believed to be the most effective technique of plant germplasm conservation. During this process, tissues are stored in liquid nitrogen (-196 °C). As a result, all metabolic functions are arrested. To prevent cells from death, a proper preparation is necessary. The aim of this study was to work out an effective, inexpensive and easy to apply method of chrysanthemum shoot tips cryopreservation, which would allow for their storage for an undefined time, and to elaborate an effective in vitro regeneration system for the purpose of breeding and horticultural industry. During the experiment, before direct immersion in liquid nitrogem, shoot tips were precultured, than encapsulated in calcium alginate and dehydrated in sucrose gradient, to prevent the material from any damage. After 1 hour, the buds were thawed and inoculated on the regeneration medium. The survival rate of the frozen material reached 85%. The growth ratio was however much lower and reached 25%.
Dyrektor Muzeum ¦l±skiego w Katowicach
Marszałek Województwa ¦l±skiego