Date: Fri, 10 Nov 2000 09:48:31 +0100
From: "Sigurd M. Såstad" <firstname.lastname@example.org>
Some additional points on moss cultures
We have been sucessfully propagating Sphagnum-clones from gametophore
fragments (branch fragments) in agar cultures for use in transplant
experiments. Our major problem has been contamination (bacterial and
fungal), and two measures have been taken to avoid this: 1) we surface
sterilise material in a a 10% chlorine solution, using the 'washing
machine' described by Basile and Basile (1988), this seems to be efficient
removing contaminants which may be stuck in between the densely packed
branch leaves. Our material generally has had no problem surviving a one
minute treatment (with three subsequent washes in destilled water) 2) we
don't use any additions of carbone to the medium. The latter measure has
reduced our loss of cultures from over 80% to below 20%. Admittedly the
cultures will grow slower with no added carbone, but so will indeed the
contaminants. Frequent reinoculation of cultures gives acceptable growth,
so that we are able to produce material suitable for transplantation to
field conditions in 5-6 months. Our experience is that the contamination
always comes from the Sphagnum itself, thus we are less strict on
autocleaving media etc. and work under sterile conditions.
Spores vs. vegetative fragments
Initiation of cultures from spores is much easier with regard to
sterilisation, however, for many purposes this may be impractical or even
impossible as one is depending on the ability of the bryophyte in question
to produce sporophytes and spores. As Sphagnum often show spatial and
temporal variation in the patterns of sporulation, such patterns limit the
use of spores in designs where spatial and/or temporal data are required.
Thus, as material for clonal propagation, we have found vegetative parts of
the gametophore offer the greatest flexibility with respect to our research
Some useful references:
Anderson, L. E., Basile, M. R. and Basile, D. V. 1992. Common garden
experiments with Sphagnum in axenic culture. - J. Bryol. 17: 15-25.
Basile, D.V. and Basile, M. R. 1988. Procedures used for the axenic culture
and experimental treatment of bryophytes. - In: Glime, J. M. (ed.), Methods
in Bryology. Hattori Botanical laboratory, Nichinan, pp. 1-16.
Såstad SM, Bakken S, Pedersen B. 1998. Propagation of Sphagnum in axenic
culture - a method for obtaining large numbers of cloned gametophores.
Lindbergia 23: 65-73.
Sigurd M. Såstad
Dept. of Natural History, NTNU
N-7491 Trondheim, Norway
tel +47-73592251, fax +47-73592249, www.ntnu.no/~vmbossaa