Control of Embryogenesis and Organogenesis in Immature Wheat Embryo Callus Using Increased Medium Osmolarity and Abscisic Acid

Abstract

The effects of various sugars, sugar alcohols and PEG, on the growth, organogenesis and embryogenesis of calli initiated from immature embryos of wheat ( Triticum aeetivum L.) were investigated. Typically, media with higher osmolarities slowed callus growth. The number of shoots per callus and the number of regenerating calli depended on the osmotic potential, carbon source and osmoticum in the medium. The onset of shoot regeneration and the extent of shooting were both increased by adding 3 % sucrose to the basal medium. The number of embryogenic calli and the size of embyogenic sectors per callus were increased by the addition of 3 % sucrose, 3 % mannitol or 5 % PEG to the basal medium. Low concentrations of ABA (0.1 and 1.0mg/l) also increased embryogenesis. The reported effects of osmotic potential, carbon source and ABA on in vitro behaviour will be of value in improving the frequency and uniformity of callus regeneration in wheat.