The effect of different carbohydrate sources upon the initiation of embryogenesis from barley microspores

Isolated microspores of Hordeum vulgare L. cv. Igri were incubated in the presence of different sugars. In the presence of maltose, the optimum concentration for the development of embryoids or calluses from the microspores was 175 mM. At this concentration 0.2% of the cells developed into embryoids or calluses. Microspores cultured without a carbohydrate source died after three days' incubation. In contrast microspores incubated in the presence of sucrose, glucose or fructose died within three days. Moreover, microspores also died when incubated in the presence of a combination of 175 mM maltose with varying concentrations of either sucrose, glucose or fructose. It is concluded that incubation of microspores in the presence of sucrose, glucose or fructose results in the death of the cells via some unknown mechanism. In contrast to this, maltose can sustain development of embryoids and calluses from cultured microspores.