Effect of growth regulators on maturation of geranium (Pelargonium × hortorum) somatic embryos

Interactions of growth regulators and polyethylene glycol on maturation of geranium somatic embryos were investigated. Somatic embryos were induced on medium with 20 μM thidiazuron for 3 days. The growth regulators used were 1 µM abscisic acid, jasmonic acid, napthaleneacetic acid and benzylaminopurine at 21 days from the start of induction. Benzylaminopurine and napthaleneacetic acid did not enhance abscisic acid effects on maturation frequency but only improved maturation frequency in the presence of polyethylene glycol. Abscisic acid significantly improved protein content in the presence of polyethylene glycol. Benzylaminopurine and napthalene acetic acid in combination with abscisic acid and jasmonic acid improved protein types in somatic embryos only in the absence of polyethylene glycol. Osmoticum effected by polyethylene glycol seems the main component required for protein synthesis. This study showed significant improvement of somatic embryo quality for artificial seed production.