Application of biostimulants for vegetative propagation of endangeredAbies gracilis

Abies gracilisKom. (Pinaceae) is one of the rarest and endangered conifers in the Russian flora, which must be cultivated ex situ to ensure its survival. Cuttings ofA. gracilisdo not take root without biostimulants. We used a selection of biostimulants, concentrations, and conditions of their use to significantly increaseAbies gracilisrooting, and to accelerate the production of planting material, and to reduce rooting time to one season. We tested 4 rooting systems: IBA, IBA with glucose and glycine, and original biostimulants (S-try and S-5). The original S-5 biostimulating system had the most balanced ratio of components. The number of rooted samples increased 2.7 times and the length of roots increased 1.8 time when using S-5 as compared to IBA. S-try and S-5-original biostimulant systems were synthesized and collected in 2011 and 2014, respectively, and were tested in St. Petersburg Forest Technical University.