Cryobanking of plant species, promise and status

Authors: Jenderek, Maria; Reed, Barbara

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/13/2015
Publication Date: 5/30/2015
Citation: Jenderek, M.M., Reed, B.M. 2015. Cryobanking of plant species, promise and status. Meeting Abstract. pp. 51. Society for In Vitro Biology, Tucson, AZ. May 30-June 6, 2015.

Interpretive Summary: Currently, the PAGRP has over 4,000 unique samples of clonally propagated species and about 49,000 seed samples in long-term liquid nitrogen storage. Cryopreservation of plant genetic resources has several advantages over germplasm maintenance in field or in vitro; the main of the advantages are protection from biotic and abiotic stress factors, small storage space needs and the possibility of long-term storage without a necessity of replanting or culture transfer. Any totipotent plant fragments can be considered for cryopreservation. In applied germplasm cryopreservation, the most commonly used explants are meristem shoots (MS) and winter dormant buds (DB) due to their low risk for somaclonal changes during the storage and regeneration. Each cryo-event requires several pretreatment steps of the processed tissue. The steps are more involved for MS than for DB; however these depend on the plant species and the cryo technique applied. The excision of meristem shoots is more laborious for monocotyledonous than for dicotyledonous species and the pretreatment steps are more involved for tropical and sub-tropical plant species than for species originating from temperate zones. Costs are trivial compared to the yearly cost of maintaining duplicate field or greenhouse collections. The initial expense of cryopreserving an accession by clonal propagules is high but the cost amortizes in a few years and the yearly maintenance cost of an accession in a liquid nitrogen tank is below $1. Cryopreservation of dormant buds is ca. 10 times less expensive than cryopreservation of meristem shoots. The USDA-ARS, National Plant Germplasm System holds over 570,000 plant germplasm accessions in field collections and under various storage conditions. The maintenance efforts of the genetic resources are enormous. Cryobanking of new plant species, beyond the currently cryopreserved, requires research on developing applicable procedures and may be challenging; however, it carries a great promise for food security in the future.

Technical Abstract: Currently, the PAGRP has over 4,000 unique samples of clonally propagated species and about 49,000 seed samples in long-term liquid nitrogen storage. Cryopreservation of plant genetic resources has several advantages over germplasm maintenance in field or in vitro; the main of the advantages are protection from biotic and abiotic stress factors, small storage space needs and the possibility of long-term storage without a necessity of replanting or culture transfer. Any totipotent plant fragments can be considered for cryopreservation. In applied germplasm cryopreservation, the most commonly used explants are meristem shoots (MS) and winter dormant buds (DB) due to their low risk for somaclonal changes during the storage and regeneration. Each cryo-event requires several pretreatment steps of the processed tissue. The steps are more involved for MS than for DB; however these depend on the plant species and the cryo technique applied. The excision of meristem shoots is more laborious for monocotyledonous than for dicotyledonous species and the pretreatment steps are more involved for tropical and sub-tropical plant species than for species originating from temperate zones. Costs are trivial compared to the yearly cost of maintaining duplicate field or greenhouse collections. The initial expense of cryopreserving an accession by clonal propagules is high but the cost amortizes in a few years and the yearly maintenance cost of an accession in a liquid nitrogen tank is below $1. Cryopreservation of dormant buds is ca. 10 times less expensive than cryopreservation of meristem shoots. The USDA-ARS, National Plant Germplasm System holds over 570,000 plant germplasm accessions in field collections and under various storage conditions. The maintenance efforts of the genetic resources are enormous. Cryobanking of new plant species, beyond the currently cryopreserved, requires research on developing applicable procedures and may be challenging; however, it carries a great promise for food security in the future.