Root Induction of Pinus Sylvestris L. Hypocotyl Cuttings using Specific Ectomycorrhizal Fungi in Vitro

Abstract

Scots pine (Pinus sylvestris L.) is one of the most widely distributed coniferous species in the world, with a natural range that stretches from Spain to large areas in Siberia (Sarvas, 1964). Genetic improvement of Scots pine by means of conventional breeding is hampered by the long generation time of the species, which is characterized by progressive transition from juvenile to the reproductive mature phase. Traditionally, the production of clonal material for Scots pine has been based on grafting. However, in seed orchards established using grafting it takes more than 15 years to produce a sufficient number of seeds (Antola, 1990). In vitro micropropagation of Scots pine using axillary buds induced on seedlings (Supriyanto & Rohr, 1994) or cotyledons excised from germinated embryos as explants has succeeded at the research level (Häggman et al., 1996). However, in practice the rooting phase has proven problematic particularly because of genotypic variation in the ability to form roots and of increased potential for plagiotrophic growth (Häggman et al., 1996).