Temporary immersion system for in vitro propagation via organogenesis of forest plant species

Key message This article summarizes the latest findings on the parameters affecting shoot efficacy in TIS and the effects of intermittent immersion on the morpho-physiological characteristics and ex vitro survival of forest plant species. Tissue culture techniques for forest plant species are essential to meet the growing demand in the global plant market and to ensure the environmental sustainability of production; therefore, it is necessary to resort to innovative tools that allow to increase the number of plants in a short time. Various propagation protocols using semi-solid media systems have been described. However, in these protocols, the use of gelling agents contributes significantly to higher costs and limits the possibility of automation in commercial propagation. The solution is to use liquid culture media, which reduces production costs and facilitates automation of the in vitro propagation process. This system not only solves some problems caused by the use of a static liquid culture medium, such as hyperhydricity, but also opens up the possibility of automating some stages of in vitro culture. However, effective control of hyperhydricity may be one reason why few forest species have been successfully propagated in temporary immersion systems. This review focuses on the use of these systems for in vitro propagation of forest plant species. The parameters affecting the efficacy of shoots in temporary immersion systems are discussed, as well as the effects of temporary immersion on the morpho-physiological characteristics and ex vitro survival of forest plant species, considering several scientific articles by researchers.