A simple way to batch propagate direct somatic embryos and kanamycin resistance of Portulaca amilis (Portulacaceae)

Plant somatic embryogenesis has critical applications in science, agriculture and industry. A successful somatic embryogenesis protocol requires optimisation on numerous factors such as growth regulators, tissue type, light, temperature, survival rate and can be species specific. Due to lack of callus phase, direct somatic embryogenesis is usually more efficient but can be recalcitrant to induce. In this study, I established an efficient, simple way to induce, regenerate and acclimatise direct somatic embryos from various young shoot tissues of three-week-old seedlings in Portulaca amilis (Portulacaceae) with high survival rate. The regenerated plantlets can be maintained in sterile environment and set seeds in vitro or acclimatised and set seeds in non-sterile environment, flexible for different purposes. The species has great potential as a model species for biochemical, physiological, medical, genetical and morphological studies. The only external hormone is 1mg/L 6-benzylaminopurine and it only takes three to four months from preparing explants from sterile seeds to mature regenerated plants setting seeds in non-sterile glasshouses. I also found out the threshold kanamycin concentration in both tissue (50mg/L) and seeds (100mg/L) for P. amilis . Both direct somatic embryogenesis and kanamycin resistance will be informative for future genetic studies involving transformation.