The use of ectomycorrhizal fungi to restore root growth during in vitro rooting and minimize losses during the acclimation of stone pine (Pinus pinea L.)

Abstract

The ICAAM Institute aims to study Mediterranean forest ecosystems in all aspects. Our Plant Breeding and Biotechnology Laboratory of ICAAM has always been involved in biotechnology of Mediterranean woody species, and has developed various in vitro techniques for vegetative propagation of Quercus and Pinus (Ragonezi et al. 2010, Zavattieri et al. 2009). The power of clonal propagation for the improvement of these woody species is indisputable. However, despite the fact that a lot of improvement in micropropagation has been made, we have always faced problems in the rooting phase (lack or reduced root growth), acclimation (water stress, loss of plants) and transfer to the field (low adaptability, low plant establishment). In this context, a few years ago we found an adequate “natural solution” for the in vitro mycorrhization. Different ECM fungi from pure and mixed stands of Pinus pinea were tested for their ability to enhance root formation and root sustainability, acclimation performance and survival of plants. Results of growth and physiological parameters during the in vitro and ex vitro acclimation phases of microplants inoculated with Phisolithus arhizus growing in different substrates and different conditions during ex vitro development and colonization will be presented. Literature Ragonezi, C., Castro, M.R., Klimaszewska, K., Lima, M., Zavattieri, M.A. 2010: Influence of light quality and intensity on adventitious root formation in microshoots of Pinus pinea L. Acta Hort., (ISHS) 865:287- 291. Zavattieri, A., Lima, M., Sobral, V., Oliveira, P., Costa, A. 2009: Effects of carbon source carbon concentration and culture conditions on in vitro rooting of Pinus pinea L. microshoots. Acta Hort., (ISHS) 812:173-180.