Rooting of Pinus radiata somatic embryos: factors involved in the success of the process

In vitro conditions of the culture media, plant growth regulators and culture containers may cause anatomical and physiological changes that have negative effects on rooting and ex vitro acclimatization of somatic plantlets. The control of these factors could contribute to the improvement of somatic embryogenesis systems in conifers, especially in pines. The influence of macronutrient concentrations, explant type and culture containers in Pinus radiata D. Don in vitro somatic embryo rooting were analyzed. The highest rooting percentage was observed using half-strength macronutrient concentrations, complete micronutrients and vitamins of Quoirin and Lepoivre medium. Although the use of glass culture vessels was the best to increase the efficiency of the somatic embryogenesis process in terms of rooting, the use of ventilated containers resulted in a significant increase in the percentage of plants able to be planted in the field.