Development of cryopreservation methods for cherry birch (Betula lenta L.), an endangered tree species in Canada

• Main Authors: Rathwell, Ricki, Popova, Elena, Shukla, Mukund R, Saxena, Praveen K
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: NRC Research Press (a division of Canadian Science Publishing) 2016
• Subjects: Canada; First Nations
• Online Access: http://hdl.handle.net/1807/73418; http://www.nrcresearchpress.com/doi/abs/10.1139/cjfr-2016-0166

Cherry birch (Betula lenta L.) is an endangered species in Canada with only a single natural population of 18 trees found in the Niagara region, Ontario. The tree was reportedly used as a medicine by First Nations and Native American peoples. The current study describes a cryopreservation method for seeds and in vitro shoot tips of B. lenta in hopes of conserving its available germplasm. Cryopreservation of mature seeds was successful with 24% seeds germinating in the greenhouse and 12% seeds germinating in vitro on medium supplemented with 10 ¾M thidiazuron or 6-benzylaminopurine. Post-cryopreservation regrowth of in vitro shoot tips was achieved using a droplet-vitrification protocol after preculture in 0.3 M sucrose for 24 hours followed by osmoprotection in loading solution for 20 min and treatment with vitrification solution A3 composed of glycerol, sucrose, ethylene glycol and dimethylsulfoxide at 0°C for 60 min. The highest plant regeneration (52%) was obtained after unloading (rehydration) in medium with 0.8 M sucrose for 30 min. Differential scanning calorimetry analysis confirmed the absence of ice crystallization in the shoot tips during cooling and rewarming. This is the first report for successful cryopreservation of B. lenta, which will further promote conservation of North American biodiversity. The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author.