The Influence of the Developmental Stage and Culture Medium upon the Somatic Embryo Induction in Quercus petraea

摘要

The somatic embryogenesis is an advanced method for clonal propagation and a useful tool for ex situ conservation of genetic resources. In this paper an experimental device was designed, composed of: one oak species (Quercus petraea), one provenance, four types of explants (developmental stages of the zygotic embryo) and four variants of culture medium. It was released the two-way statistical analyses of the two analyzed factors affecting the embryo induction efficiency: the stage of explant and culture medium (4 stages x 4 culture media). The most important factor affecting the efficiency of somatic embryogenesis was found to be the developmental stage of the zygotic embryos used as juvenile explants. The high embryogenic ability of young zygotic embryos and low embryogenic ability of maturing zygotic ones showed the strong positive relationship between somatic embryo induction and accumulation of reserve nutrients in cotyledons. The best results were obtained with the youngest embryos (stage 1), with a linear decrement towards the stage 4. The embryo induction efficiency ranged between 44% and 10% in Q. petraea. Two nutritive culture media and two growth hormone combinations were tested. The effect of culture medium proved to be totally insignificant, besides the differences observed among the variants cultivated on different media. The situation was the same as well for the nutrients as for growth regulators.