|KAYA, ERGUN - The Gebze Institute Of Technology|
|ALVES, ALFREDO - Labex - Embrapa|
|RODRIGUES, LOE - Universidade Federal De Lavras|
|HERNANDEZ-ELLIS, MARGARITA - Non ARS Employee|
|OZUDIGRU, AILYN - National Research Council - Italy|
Submitted to: CryoLetters
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/1/2013
Publication Date: 12/1/2013
Citation: Kaya, E., Alves, A., Rodrigues, L., Jenderek, M.M., Hernandez-Ellis, M., Ozudigru, A., Ellis, D.D. 2013. Cryopreservation of eucalyptus genetic resources. CryoLetters. 34:608-618.
Interpretive Summary: The long-term preservation of forest genetic resources is vital for preserving our forest crops for future generations. Unfortunately there are few methods aside from field plantings of genetically diverse germplasm collections for preserving the diversity of forest trees or individual trees identified for superior traits. The use of liquid nitrogen (-320oF) for the long-term storage of elite germplasm is being used with agronomic crops yet for forest trees, such as Eucalyptus, the methodologies for this low temperature storage (known as cryopreservation) of diverse genetic resources collections has not been established. In this paper, we report the development of a successful method for the cryopreservation of a germplasm collection of thirteen Eucalyptus spp lines consisting of two E. grandis x E. camadulensis lines, seven E. urophylla x E. grandis lines, one E. grandis line, two E. grandis x E. urophylla lines, and one E. camadulensis line. We employed the use of a cryoprotectant, Plant Vitrification Solution 2 (PVS2), to precondition tiny growing shoot tips to survive the freezing and thawing process. Using a 30 minute exposure to PVS2 we were able to achieve a post-liquid nitrogen survival between 38% and 85% depending on the line. These lines are now securely preserved long-term so that they are available to future generations.
Technical Abstract: The long-term preservation of forest genetic resources is a vital part of preserving our forest crops for future generations. Unfortunately there are few genebanks dedicated to forest trees and very few methods aside from field plantings of germplasm collections of elite clonal individuals. The use of cryopreservation for the long-term storage of elite germplasm is making good headway with agronomic crops but for forest trees, such as Eucalyptus, the methodology for cryopreservation of diverse genetic resources collections has not been established. We report the successful cryopreservation of a germplasm collection of in vitro shoot cultures of thirteen Eucalyptus lines. While sucrose sensitivity limited the application of encapsulation-dehydration, with droplet vitrification all thirteen lines had good survival after liquid nitrogen. A 30 minutes exposure to PVS2 yielded post-liquid nitrogen survival between 38% and 85% depending on the line. One hundred shoot tips from all thirteen lines are currently in long-term storage as a germplasm collection.