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ARS Home » Pacific West Area » Corvallis, Oregon » National Clonal Germplasm Repository » Research » Publications at this Location » Publication #283025

Title: Cryopreservation of medicinal plants: role of melatonin

Author
item UCHENDU, ESTHER - University Of Guelph
item SHUKLA, KUKUND - University Of Guelph
item Reed, Barbara
item SAXENA, P. - University Of Guelph

Submitted to: Acta Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/15/2013
Publication Date: 6/23/2014
Citation: Uchendu, E.E., Shukla, K.R., Reed, B.M., Saxena, P.K. 2014. Cryopreservation of medicinal plants: role of melatonin. Acta Horticulturae. 1039:233-242.

Interpretive Summary: Many useful plant species found in Canada are of conservation concern. Storage of tissue cultures and cryopreservation in liquid nitrogen ensures safety of these species. Shoot tips of tissue cultured plantlets of American elm, St John’s Wort, tobacco and dormant winter buds of American elm were successfully cryopreserved in liquid nitrogen at -196 °C under controlled environment conditions following melatonin treatment and cold acclimation (CA). The antioxidant chemical melatonin added at two steps of the protocol improved regrowth of all three plant types. Under optimized conditions for cryopreservation of these species, the protocols resulted in 80 to 100% regrowth for all plant types. Shoot tips of dormant winter buds of the American elm consistently produced nearly 100% regrowth. This study indicates that antioxidant melatonin improves recovery of cryopreserved tissue and enables long-term storage of these economic species.

Technical Abstract: Many useful plant species found in Canada are of conservation concern. In vitro storage and cryopreservation techniques guarantees safety of these species and have potential applications which may result in sustainable agriculture. Shoot tips of in vitro-grown plantlets of American elm, St John’s Wort, tobacco and dormant winter buds of American elm were successfully cryopreserved in liquid nitrogen at -196 °C under controlled environment conditions following melatonin treatment and cold acclimation (CA) with either vitrification or encapsulation-vitrification protocols. Explants of St John’s Wort and tobacco had optimal regrowth following cryopreservation, when treated with the Plant Vitrification Solution #2 (PVS2) for 20 min on ice and those of American elm for 10 min on ice. Melatonin (0.1 µM), added to both preculture and regrowth medium significantly enhanced regrowth compared to the control (p<0.05). Under optimized conditions for cryopreservation of these species, the two protocols resulted in 80 to 100% regrowth for all plant types. Shoot tips of dormant winter buds of the American elm consistently produced nearly 100% regrowth with both techniques. This study indicates that antioxidant melatonin improves recovery of cryopreserved tissue and is a very viable option for long-term storage of these economic species. We recommend a 14 d CA; 24 h preculture of explants on medium with 0.1-0.5µM melatonin; application of PVS2 for 10 or 20 min depending on the plant; rapid cooling in liquid nitrogen; rapid rewarming process; removal of cryoprotectants; and recovery on 0.1-0.5µM melatonin medium.