Dugotrajno čuvanje germplazme voćaka primenom in vitro tehnika za krioprezervaciju vrhova izdanaka u Institutu za voćarstvo, Čačak | Long-term conservation of fruit tree germplasm using different in vitro cryopreservation techniques at Fruit Research Institute, Čačak

Cryopreservation represents contemporary method for long-term conservation of plant germplasm at ultralow temperature (liquid nitrogen, -196oC). Since cryopreservation reduces cost and risks linked to management of field germplasm collections, it has become a complementary approach to conventional conservation methods. Program for application of this strategy was also initiated within Department of Fruit Physiology of FRI, ^a~ak more than a decade ago. Most of the research has been focused on optimization of the protocols for different vitrification-based cryopreservation techniques and their application for conserving temperate fruit tree genotypes. Encapsulation-dehydration technique has been successfully applied for cryopreservation of cherry plum and blackberry ‘Čačanska Bestrna’. Research on application of vitrification technique for conservation of Prunus and Malus germplasm has shown that significant increase in regrowth of cryopreserved shoot tips of cherry rootstock ‘Gisela 5’ and apple ‘Gala Must’ can be achieved by varying duration of dehydration and/or type of vitrification solution (VS) employed. Optimization of the droplet-vitrification protocol in representatives of Prunus (plums ‘Crvena Ranka’, ‘Sitnica’, ‘Požegača’, and ‘Krina’, cherry plum, rootstock ‘Gisela 5’), Malus (apple ‘Gala Must’) and Rubus (blackberry ‘Čačanska Bestrna’) genera was performed by evaluating the effect of different VSs, treatment durations, temperature of dehydration and duration of unloading on recovery of cryopreserved explants. Recently, the research on application of newly developed V and D cryo-plate techniques has been initiated, too. These methods allow overcoming disadvantages of other vitrification procedures such as mistiming dehydration, damage and loss of material and manipulative problems. Shoot tips of number of autochthonous plums (‘Crvena Ranka’, ‘Požegača’, ‘Sitnica’, ‘Moravka’, ‘Belošljiva’), cherry plum, rootstock ‘Gisela 5’, strawberry ‘Clery’, blueberry ‘Toro’ and saskatoon (Amelanchier alnifolia) were successfully cryopreserved using these methods. Results obtained in this research represent a substantial contribution to establishing optimized conservation technology by application of different vitrification based cryopreservation techniques, as well as a good basis for further optimization of the protocols that will be possible to directly implement in the future program of establishing an in vitro germplasm bank of fruit tree species in our country.