Effect of temperature and osmotic stress during somatic embryogenesis on phenology and physiology of abies nordmanniana emblings

Epigenetic modification induced during embryogenesis can serve as a mechanism for rapid adaptation of plants to climate change, especially for long living organisms such as trees. Here, we test if temperature and osmotic stress during embryogenesis influences spring and autumn phenology, photosynthesis rate, growth and water stress tolerance in Abies nordmanniana. Somatic embryogenic plants (emblings) were developed under different temperatures to test if temperature influences the spring phenology. Our results show that 9 °C higher temperature during somatic embryogenesis advanced budburst by an average of 4 days, but with significant differences among different genotypes in their response. This reveals genetic variation in the observed phenological response to temperature during somatic embryogenesis. However, we did not observe an effect of differences in osmotic stress during somatic embryogenesis on the response of the emblings to water stress. Optimum temperatures for photosynthesis and maximal photosynthetic rates were not found to be influenced by the temperature during somatic embryogenesis. Both height and autumn senescence were significantly different among the genotypes, but the temperature during somatic embryogenesis did not affect these traits. The observed responses in our study complement findings from other species and support that epigenetic modification in phenology may help the species to cope with fluctuations in temperatures in future climate, and may have practical applications for reducing spring frost risk in plantations of the species.