Cryopreservation of callus cells of grain crops in electric freezer

Modern breeding of cereals such as wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) is complemented by biotechnological methods, including in vitro cell selection and genetic transformation. For long-term preservation of the resulting unique cell lines and minimisation of genetic changes, the scientists should use cryopreservation, which halts metabolism and eliminates the need for regular passages. The aim of this study was to evaluate the efficiency of cryopreservation media (glycerol, glycerol and apple pectin) for preserving spring barley and wheat callus cells at –80 °C in a domestic electric freezer. Barley (four lines) and wheat (two lines) calli obtained from immature embryos were used. Callus cells were frozen under the protection of cryopreservative media in electric freezer at –80 °C for seven days, followed by cultivation of thawed callus cells in a nutrient medium. Before cooling and after thawing, we assessed the viability of callus cells using a vital dye. The ability of cells to regenerate after thawing was also assessed. After exposure to subzero temperatures using cryopreservation solutions, the cell membrane integrity of both barley and wheat calli, regardless of genotype, was consistently maintained at 50 %. Thus, the use of cryopreservation media (glycerol, glycerol and apple pectin) for preserving spring wheat and barley callus cells at –80 °C in a domestic electric freezer is successful in maintaining the cell membrane integrity of callus cells.