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ARS Home » Pacific West Area » Corvallis, Oregon » National Clonal Germplasm Repository » Research » Publications at this Location » Publication #207367
Title: A Comparative Study of Three Cryopreservation Protocols for Effective Storage of Mint (Mentha spp.)

Author
item UCHENDU, ESTHER - OREGON STATE UNIVERSITY
item Reed, Barbara

Submitted to: In Vitro Cellular and Developmental Biology
Publication Type: Abstract Only
Publication Acceptance Date: 5/20/2007
Publication Date: 5/20/2007
Citation: Uchendu, E.E., Reed, B.M. 2007. A comparative study of three cryopreservation protocols for effective storage of mint (mentha spp.). In Vitro Cellular and Developmental Biology. 43:545.

Interpretive Summary: Four mints from the tissue culture collections of the USDA-ARS National Clonal Germplasm Repository (NCGR), Corvallis, were tested for storage in liquid nitrogen (-320°F) using three standard protocols: controlled cooling (slowly cooled to -40°C then plunged in liquid nitrogen), encapsulation dehydration (enclosed in a gel bead, dried, then plunged in liquid nitrogen), and vitrification (treated with antifreeze solutions and plunged in liquid nitrogen). All four mints responded well to the controlled cooling protocol. Regrowth following controlled cooling was significantly better than the other two methods. These results indicate that controlled cooling was the most successful technique, however, shoot tip recovery from vitrification and encapsulation dehydration was usually high enough that these techniques could also be safely used for cryogenic storage of mint.

Technical Abstract: Four mint species [Mentha x piperita citrata (Ehrh.) Briq. (PI 557993); M. canadensis L., (PI 557613); M. australis R.Br, (PI 617498) and M. cunninghamii Benth, (PI 617481)] from the in vitro collections of the USDA-ARS National Clonal Germplasm Repository (NCGR), Corvallis, were cryopreserved using three standard protocols: controlled cooling (CC), encapsulation dehydration (ED), and PVS2 vitrification (VIT). All plants were cultured on MS medium with 0.5 mgl-1 benzyladenine (BA), 0.1 mgl-1 indole 3 butyric acid (IBA) and cold acclimated for 2 weeks before cryopreservation. Shoot tips were recovered on medium without IBA. All four genotypes responded well to the controlled cooling protocol. Regrowth following controlled cooling (93%) was significantly better (p<0.05) than for encapsulation dehydration (71%) or vitrification (73%). Recovery of Mentha x piperita citrata and M. australis showed significant differences among the three techniques with CC > VIT > ED. There were also significant differences in the recovery of M. canadensis and M. cunninghamii with CC and ED significantly better than VIT. Overall, regrowth of the genotypes was 60% to 90% for all but one treatment. These results indicate that controlled cooling was the most successful technique, however, recovery of shoot tips from VIT and ED was usually high enough that these techniques could also be used for cryogenic storage of mint germplasm.