U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 Agricultural Genetic Resources Preservation Research: Fort Collins, CO
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                People

                    Staff Listing
                                    CareersSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Plains Area Fort Collins, Colorado Center for Agricultural Resources Research Agricultural Genetic Resources Preservation Research Docs Clonal







Welcome to the Clonally Maintained Plant Germplasm Cryopreservation Program Protocols    Statistics
Collage of tissue cultures growing on media, alginate beads, cryo tanks, storage tubes, and seedlings Plants that do not produce seeds, or if grown from seeds would not result in the same appearance and characteristics as the original plant, are propagated vegetatively or clonally. Examples of plant tissues that can produce a whole plant include shoots, root or stem fragments, dormant buds, or somatic embryos. Plants resulting from these plant parts are called clones because they will have the same qualities as the donor plant. For this reason these plant tissues can also be used in the cryopreservation of clonally propagated accessions. Our program preserves genetic resources provided by the crop-specific active field sites of the National Plant Germplasm System (NPGS) and selected Plant Variety Protection (PVP) voucher samples. Currently, the majority of cryopreservation techniques for clonally maintained germplasm use tissue culture.
plant tissues growing on media in cubes However, the PAGRPRU also preserves plant material as dormant winter buds. The choice of tissue being cryopreserved depends on availability of reliable cryopreservation protocols. In close collaboration with the NPGS curators, the group carries out applied research that improves and/or develops cryopreservation techniques that promote efficient long-term germplasm storage. Some of our current research projects focus on: Establishing optimal harvest time for almond (*Prunus dulcis*), apricot (*P. armeniaca*) and blueberry (*Vaccinium* hybr.) dormant winter buds used for cryopreservation. The ability of buds to survive low temperatures (-158 to -196°C) during storage depends on several factors; one of the factors is the sugar concentration at the time of cryoprocessing. The sugar concentration in dormant buds  changes as the tree physiological stages change. Analyzing the sugar concentration over a growing season and correlating it with post cryopreservation survival will help to determine the optimal harvest time for the bud long-term storage in liquid nitrogen. Developing procedures for long-term storage of cacao (*Theobroma cacao*) genetic resources. Cacao genetic resources are difficult to cryopreserve. Seeds of cacao are considered as recalcitrant in storage; cacao cultivars or selections are preserved vegetatively. Our project studies the suitability of different plant tissues for storage in liquid nitrogen, pre-treatment procedures and testing techniques for viability after cryopreservation to determine the most suitable method for long-term storage of cacao vegetatively maintained germplasm. Improvement of cryopreservation techniques for pineapple (*Ananas* spp.) cultivars, selections and breeding lines.After cryopreservation viability of different pineapple genotypes varies. This project evaluates the fitness of available cryopreservation techniques for long-term storage and tests different pretreatments to improve survival of meristematic shoots in liquid nitrogen.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov