Bread wheat callusogenesis and organogenesis using mature embryos as explants

Abstract

Background. Bread wheat (Triticum aestivum L.) is one of the staple cereal crops, so it is of great interest to breeders and researchers and requires constant monitoring of existing cultivars, including the development of new ones through classical breeding and modern gene engineering. The key stage in these techniques is successful callusogenesis and organogenesis in target objects. With this in view, the regeneration potential of two spring (‘Saratovskaya 55’ and ‘Sigma’) and three winter (‘Tanya’, ‘Fisht’ and ‘Pamyat’) cultivars of bread wheat was assessed, and optimal conditions were identified for callus induction and organogenesis using mature embryos. Materials and methods. Immature and mature embryos of the five bread wheat cultivars were used in the study. The in vitro morphogenetic potential was evaluated under the impact of abiotic factors: preliminary exposure of grains to cold and use of exogenous hormones (2,4-D in various concentrations). Pretreatment of wheat with cold was carried out as follows: sterilized grains were incubated on the hormonal medium at a temperature of 4 °C for 2 weeks, and then transferred to 26 °C for 4 more weeks. The efficiency of callusogenesis and rhizogenesis was assessed and the numbers of morphogenetic calluses, regenerated and acclimatized plants were calculated. Results and conclusions. The analysis made it possible to identify the bread wheat cultivars ‘Fisht’ and ‘Sigma’ for their high morphogenetic and regenerative potential. It was also shown that exposure to cold can serve as a good stimulating factor for producing a large number of calluses, but regenerants are better induced under normal conditions. The results also depended on the concentration of hormones applied. Universal conditions for morphogenesis and regeneration were not identified.

Keywords

• spring wheat
• winter wheat
• callusogenesis
• regeneration
• cold pretreatment
• 2,4-d