Cryopreservation of several Ribes species by dormant winter buds

Abstract

Currant and gooseberry plants (Ribes L.) are native to the temperate regions of the Northern hemisphere through high elevations in Mexico and Central America to the mountainous regions of South America. Annually, the global production is about 838 MT. The fruits are used for cassis, juice preserves, in bakery, dairy products and pharmaceuticals. Some species such as black currant (Ribes nigrum) have antimicrobial, antitumor and immunostimulatory qualities; hence, interest is growing in crop improvement using a diversity of plant genetic resources. Active germplasm collections preserve Ribes cultivars as clonal plantations in the field or under protected cultivation, and species as plants in the field or seeds in cold storage. Long-term preservation of Ribes germplasm may be accomplished by various methods, one of them is cryopreservation of dormant winter buds (DB). This method is reported for preservation of R. nigrum. We have investigated the possibility of applying DBs for cryopreservation of other Ribes species. Eleven accessions in seven species (R. aureum var. aureum, R. aureum var. villosum, R. cereum, R. erythrocarpum, R. mascalerium, R. turbinatum and R. uva-crispa) were cryopreserved over two winter seasons without a pretreatment (standard), with a cryoprotectant (0.75 M sucrose) or a cryoprotectant with an antioxidant (0.75 M sucrose with 0.75 mM vitamin C). A 2-year average viability varied significantly among the accessions processed with the standard method (10 to 87.5%) and among accessions processed with the pretreatments (32.5 to 97.5%); however, the difference between the standard and treatment procedures was not significant. A significant difference in viability between the processing years was observed and there was an interaction between accession, year and treatments for seven accessions processed in three treatments but not in the four accessions processed in the two treatments. Cryopreservation of the broad species in the Ribes germplasm collection may be supported by identifying modifications of the standard cryopreservation procedure.