IN VITRO STORAGE OF HOP (HUMULUS L.) GERMPLASM
In this study we characterized the response of 70 diverse Humulus L. genotypes from the USDA-ARS National Clonal Germplasm Repository, Corvallis, Oregon, to in vitro storage under low light at 4° C and 28 to cryopreservation in liquid nitrogen by slow cooling. Plantlets were cold acclimated, stored in plastic tissue-culture bags, and evaluated at 4 mo intervals. The average storage time without transfer for the 70 genotypes evaluated was 14.1 ± 3.5 mo with a range of 6 to 26 mo. Eight accessions stored for 2 cycles averaged 14.3 ± 3.2 months storage. Plantlets for cryopreservation were cold acclimated for 2 wks, pretreated for 48 hrs, cooled to -40° C at 1° C per min, and plunged into liquid nitrogen. Mean recovery of cryopreserved shoot tips of accessions was 54% ± 13 with 2-wk cold acclimation. A few genotypes required longer cold acclimation for good recovery following liquid nitrogen exposure.
Reed, B.M. (2005). IN VITRO STORAGE OF HOP (HUMULUS L.) GERMPLASM. Acta Hortic. 668, 249-256
cryopreservation, cold acclimation, cold storage, Humulus lupulus, liquid nitrogen, tissue culture