|Denoma, Jeanine - OREGON STATE UNIVERSITY|
|Chang, Yongjian - OREGON STATE UNIVERSITY|
Submitted to: Plant Genetic Resources International Board Newsletter
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 18, 1998
Publication Date: N/A
Interpretive Summary: Duplicate collections of pear trees from arround the world are now preserved in two ways: using refrigerated tissue cultured plants or stored in liquid nitrogen (cryopreserved). The in vitro cultured plants can be stored without repropagation for one to five years and remain alive. The cryopreserved pears we anticipate will survive for 100 or more years. Ten percent (169 accessions) of the pear trees held at the National Clonal Germplasm Repository are also kept as tissue cultures in refridgerator temperature storage. Meristems (small shoot tips) of more than 50 types of pears are now stored in liquid nitrogen. More than 100 additional pears were screened for survival following brief freezing in liquid nitrogen. pear meristems are stored in liquid nitrogen at the National Seed Storage As an added security precaution, cryopreserved pear meristems are stored in a remote location at the National Seed Storage Laboratory, Fort Collins, ,Colorado.
Technical Abstract: The security of genetic resource collections mandate preservation by several techniques. Duplicate collections of field-grown pear genetic resources are now preserved in medium and long-term storage using cold rooms or liquid nitrogen dewars. Ten percent (169 accessions) of the primary pear field collection held at the National Clonal Germplasm Repository are kept as in vitro cultures in 4 degree C storage in polyethylene tissue culture bags. In vitro cultures were stored under refrigerated temperatures for 8 months to 4.7 yr with a mean storage time of 2.75 yr. Meristems for more than 50 peear accessions are stored in liquid nitrogen. More than 100 additional genotypes have been screened for survival following cryopreserved storage. As an added security precaution cryopreserved pear meristems are stored in liquid nitrogenat the National Seed Storage Laboratory, Fort Collins, Colorado as a remote long-term base collection.