Kuehllagerung von Gewebekulturen : Erhaltung forstlicher Genressourcen. Vortragstagung der Arbeitsgemeinschaft fuer Forstgenetik und Forstpflanzenzuechtung

1990

S. 137-144

3 Tab., 4 Lit. Ang.

Unselbständiges Werk

200045078

Beside the conventional ways of storing genetic resources in vitro culure techniques provide complementary methods. These are cryopreservation of tisues or organs (CHEN & KARTHA, 1987) and cold storage (AITKEN-CHRISTE & SINGH, 1987; WITHERS, 1985). The temperature for old storage ranges from 0 to + 15 Grad C depending onthe species. In case of woody plants usually shoot or plantlet cultures are cold-stoed. Successful cold storage is possible under a low light intensity or even in the dark. Shoot cultures are normally placed in the cold storage one to three weeks after their last transfer. Shoots of woody species have been successfully coldstored for up to two years. After this period a regenertion under normal culture conditions is necessary. The cultures can be placed in the cold storage again. By repeating this procedure at regular intervals the cultures will be maintained without limit. At the Lower Saxony Foest Research Institute Quercus, Betula, Sorbus, Malus, Prunus and Pinus have been successfully coldstored under slow growth conditions (+ 4 Grad C, 12 h photoperiod under low light intensity) over a period of 13 to 27 months (Tab. 2). The regeneration after cold storage was well, apples even showed an increased multiplication rate (Tab. 3). A long-term storage can be used in tree breeding and clonal forestry programs. Embryos from high quality seed can be isolated and multiplied in vitro. Material from each clone is cold-stored and field-tested. When the results of the field testing are available the superior clones ca be easily multiplied out of the cold-stored stock culture. Cold storage of in vitro shoot cultures for germplasm preservation purposes has several advantages. It uses less space than conventional methods, avoids losses by diseases, insects or air pollution and may cause lower costs than ex situ plantations. A disadvantage of in vitro methods is the unevitable selection for suitability for in vitro culture. It has still to be determined if cold-stored cultures remain juvenile and genetically stable.