Date: Thu, 09 Nov 2000 23:57:52 -0800
From: Wayne Tyson <firstname.lastname@example.org>
To: email@example.com, firstname.lastname@example.org
>In reply to Janice.
>Thanks for the additional info concerning what you have in culture.
>Bugs, algae, cyanobacteria (perhaps not quite so problematic) and
>fungi (perhaps the worst of all) are all hazards to be faced. In bulk
>culture in a "free" place (i.e., in the open or in a terrarium), these
>can be a problem (Janice has mentioned in particular the bugs).
>In culture on a solid medium (Agar or other alternative medium
[[Would you cite some examples, with pros and cons and relationships to
substrates--and substrate requirements as well as limiting factors in
>bugs are not so much of a problem as fungi, algae and
>cyanobacteria - in that order.
[[While inconvenient and time-consuming, might there be hope for an
"ecological mimicry" procedure whereby fungal, algal, and cyanobacterial
"succession" phenomena could be accelerated and/or conditions favorable to
bryophytes established short of sterilization? Particularly for
>One species Janice and Peg have in culture interested me:
>Lunularia cruciata. Perhaps this primarily southern hemisphere
>taxon is a northern novelty. But, in the wild, it is a particularly
>robust bryophyte. If it is found in wet shaded habitats it produces
>almost entirely gemmae. In sites that are more exposed and drier
>and subject to periods of desiccation, it produced both gemmae
>(when the conditions are wettest - e.g., autumn and winter) and at
>the end of Spring, it forms sporophytes - but these develop only to
>a "bud" stage i.e., the small white cones near the thallus apex.
>These sporophytes (complete with elaters and spores, I might add)
>remain in a state of suspended animation until the following autumn
>rains, when there will be a burst of growth and maturation with
>spore release. In summer, the plants become "cooked" on the soil
>surface, and large areas of a thallus (but not the part with the
>sporophyte) may die. A good example of a bryophyte finely tuned
>to its habitat.
[[What is known about the conditions of habitat that favor and limit
bryophyte growth in "the wild," for example the species mentioned?]]
>On the subject of cultures: I have just been to have a look at what
>Jane Burch (Micropropagation Unit at Kew Gardens, London) is
>doing with her experimental studies on culturing bryophytes with
>particular regard to the ex situ conservation of rare or endangered
>species. Axenic culture is not necessarily an easy thing to
[[What are the primary factors limiting success? Do fungi confer any
benefits, particularly with respect to natural [micro-]site modification,
such as physical and/or chemical alteration of site conditions? In my
limited and terribly ignorant observations, there appears to be a
"succession" process with bryophytes at the "climax." Could fungal, algal,
cyanobacterial and other metabolites and breakdown products be producing a
film-like substrate analogous to algin in the lab? What about other
bacteria, such as free-living N-fixers? Would anyone be interested in
looking at field samples? Do I presume correctly that someone is looking
(or already has looked at) such ecological phenomena?]]
>I was impressed by what can be done with a little experimentation
>(and, obviously time and care). Perhaps, Jane, the basics of your
>methodology could be shared on the net.
>Perhaps, some general questions for discussion:
>For those who have experience in axenic culture of bryophytes,
>what method is being used to surface sterilise the material?
>How effective is the technique in (i) providing surface sterility and
>(ii) not killing or damaging the bryophyte tissue.
>Perhaps, also, for propagationists who wish to share their
>techniques, may be the culture medium and nutrient sources.
>Public opinion would seem to dictate that it is only showy vascular
>plants that get much attention with regard to conservation.
>However, one intersting feature of Jane's work at Kew is the culture
>of a relatively recently described species of the moss Ditrichum -
>the type locality of which no longer exists!!
[[In 1969 I suggested that a local area be preserved in lieu of planting a
Bermuda-grass lawn in a large park and was promptly branded as one of
suspect character, political and sexual affiliations. Needless to say, I
needled them evermore...]]
>Prof. Rod Seppelt
>Royal Botanic Gardens, Kew
>Richmond, Surrey TW9 3AB