In vitro conservation of fruit trees by slow growth storage

Abstract

In vitro culture has been confirmed today as a useful tool that facilitates the multiplication and conservation of genetic resources from vegetatively propagated species. Slow growth enables storage with lower labor costs. Low temperature, darkness and an adequate culture medium were the considered parameters when establishing the slow growth conditions. The aim of this work is to develop a routine protocol to maintain cultures for a wide variety of fruit tree genotypes. 138 different fruit-trees belonging to 18 species from Prunus, Punica, Ficus, Cydonia, Pyrus, Malus, Eriobotrya and Crataegus were maintained at 3-4°C, in darkness or continuous light, in order to compare two culture media for 7 or 12 months. Culture media were determinant in the multiplication and in the time for complete recovery of the optimal shoot growth in the genera Crataegus and Eriobotrya, while not in the rest. Continuous lighting was detrimental under these conditions for all the clones. Conservation for 12 months led to more shoot death, but only LSQUOCadamanRSQUO (Prunus persica × P. davidiana) and one clone of Punica granatum did not adapt to these slow growth conditions. The protocol presented here enabled the conservation for 12 months of 99% of the clones.