BEN # 203

Adolf Ceska aceska at VICTORIA.TC.CA
Thu Sep 24 02:15:34 EST 1998


                                                   
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No. 203                              September 23, 1998

aceska at victoria.tc.ca                Victoria, B.C.
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 Dr. A. Ceska, P.O.Box 8546, Victoria, B.C. Canada V8W 3S2
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RARE PLANT SYMPOSIUM - UBC VANCOUVER, B.C. - OCTOBER 17, 1998
From: Patrick Williston <patrickw at interchange.ubc.ca>

What:  "Living  on  the  Edge: a symposium on the rare plants of
           British Columbia"
   
   An afternoon symposium addressing some  of  the  issues  sur-
   rounding  the rare plants and plant communities of BC. Topics
   will include rare mosses, liverworts, ferns and aquatics,  as
   well  as  the  rare  Coastal  Douglas fir zone grasslands and
   vascular plant conservation  issues  in  the  Fraser  Valley.
   Among the invited speakers will be Adolf Ceska of the Conser-
   vation  Data  Centre, Hans Roemer of the Ministry of Environ-
   ment, Wilf Schofield and Fred Ganders from the UBC Department
   of Botany, Brenda Costanzo from the  University  of  Victoria
   Biology Department, and others.

   The  symposium will also feature a showing of original paint-
   ings by Oluna Ceska  and  Lesley  Bohm  illustrating  British
   Columbia's flora.

When: October 17, 1998 1:00-6:00 pm

Where: University of British Columbia, Vancouver, B.C. 
   Bioscience 2000. 6270 University Blvd. (next building west of 
   the bookstore).

Who:  Patrick  Williston and Kelly Bannister are organizing this
   symposium jointly supported by the Botany  Graduate  Students
   Society  and  the  NPSBC  -  Native  Plant Society of British
   Columbia.

How much: Student $5. Regular $8 at the door.

Need more information? Contact Patrick Williston  (604)-266-7903
   or patrickw at interchange.ubc.ca


THE TWISTING TALE OF THE BLACK TRUFFLE (TUBER MELANOSPORUM)
From:  Bertault,  G.,  M.  Raymond,  A. Berthomieu, G. Callot, &
   D. Fernandez c/o <bertault at isem.univ-montp2.fr>

Of the ten species of European  truffles  (fungi  of  the  genus
Tuber,  phylum  Ascomycota), the Black Truffle, Tuber melanospo-
rum, is among the most valuable. Its taste and perfume has  made
it  famous  for connoisseurs, and no restaurant can achieve true
distinction unless it includes it in its  menu.  An  interesting
fact is the differences displayed by the fungus according to its
geographical  origin:  a  specialist  can tell whether a truffle
comes from one place or another. We attempted to determine which
factor, either nature or nurture (i.e. genetic or  environmental
grounds)  was  responsible  for  this variation by assessing the
genetic diversity on a sample as large as possible (Bertault  et
al.  1998).  More  than  200  ascocarps  were  investigated  for
microsatellite  and  Random  Amplified  Polymorphic  DNA  (RAPD)
variability,  and  the relation between this variability and the
geographic distance between truffles was tested.

Two striking results appeared:
 1. We found out that the Black Truffle displayed  an  amazingly
    low  degree  of genetic diversity, that could not compare to
    that found in some other  Tuber  species  (e.g., the  Summer
    Truffle,  Tuber  aestivum).  This result confirms those pre-
    viously found on small samples of  various  truffle  species
    (see e.g., Gandeboeuf 1997).
 2. We  could  not relate the little amount of genetic diversity
    found with the geographic distance between samples. In other
    words, truffles far away from  one  another  were  not  more
    genetically  diverse  than  truffles  coming  from  the same
    place.

These two facts enabled us to hypothesize that the Black Truffle
had experienced a drastic reduction in number  during  the  last
glacial  period  that  ended  some 10,000 years ago. Indeed, the
fungus' range has probably been  restricted  to  a  few  refugia
(maybe  even  only to a single one) in its southernmost limit of
distribution. During this period, it could thus have lost almost
all of its former genetic diversity, and a rapid  recolonization
of  its  previous  range  would not have allowed the isolates to
differentiate.

The Black Truffle ripens in winter, is very sensitive to  frost,
and  suffers  more  from  cold than does the Summer Truffle. The
Summer Truffle is dormant through the winter and it  has  higher
tolerance  to  cold.  During  the  glacial  period it might have
occupied a wider range  than  the  Black  Truffle  did,  and  it
retained higher genetic variation.

According  to  our  findings,  two  conclusions can be drawn for
truffle growing and collecting:
 1. The absence  of  genetic  differentiation  for  neutral  and
    anonymous  DNA  markers led us to advise against any program
    dealing with determining  subspecies  or  cross-breeding  of
    different strains in order to improve the genetic content of
    the  truffles, since they all seem to be genetically identi-
    cal regardless of the place where they were sampled.
 2. A special attention should  be  paid  to  the  environmental
    factors (e.g., soil, climate & associated tree species) that
    seem to rule the taste and perfume of the Black Truffle.

References:

Bertault, G., Raymond, M., Berthomieu, A., Callot, G. &  Fernan-
   dez,  D.  1998.  Trifling variation in truffles. Nature, 394:
   734.
Gandeboeuf, D., Dupre, C., Roeckel-Drevet, P.,  Nicolas,  P.  et
   Chevalier,  G.  1997.  Grouping  and  identification of Tuber
   species using RAPD markers. Canadian Journal of  Botany,  75:
   35-45.

Authors:

Bertault, G., Raymond, M., Berthomieu, A.
   Institut  des  Sciences de l'Evolution, Laboratoire Genetique
   et Environnement Cc  65,  Universite  Montpellier  II,  34095
   Montpellier Cedex 05, France.
Callot, G.
   Institut  des  Sciences  du  Sol,  Institut  National  de  la
   Recherche Agronomique, Place Viala, 34060  Montpellier  Cedex
   01, France.
Fernandez, D
   Laboratoire  de  Phytopathologie  Comparee,  ORSTOM, BP 5045,
   34032 Montpellier Cedex 01, France.


ERYTHRONIUM GRANDIFLORUM: ECOLOGY & ETHNOBOTANY
From: Dawn Loewen <dcl at larch.geog.uvic.ca>

I would  like  very  much  to  thank  the  countless  wonderful,
altruistic  botanists  and naturalists who took the time to con-
tact me via my "Erythronium hotline" with  site  information  or
who  otherwise  took  an  interest in my project. I finished and
defended my thesis in summer 1998.

Thesis abstract:

This  research  examined  a  single  bulb-bearing  edible  plant
species,  yellow  glacier lily (Erythronium grandiflorum). Three
main approaches to the research were taken:
 1. an ecological study, to determine the  general  habitat  re-
    quirements  of  the species in western Canada, and to inves-
    tigate the nature of vegetative reproduction in the species;
 2. an ethnobotanical study, consisting of an extensive  litera-
    ture  search  for  all  recorded  First Nations' uses of the
    species (in Canada and elsewhere), in addition to interviews
    with contemporary Interior Salish elders;
 3. a nutritional study, examining  in  detail  the  nutritional
    characteristics  of  the  bulbs, and particularly changes in
    the carbohydrate content over  the  course  of  the  growing
    season and with different types of treatments.

The  ecological  data  indicate that Erythronium grandiflorum is
more abundant in meadow environments  or  sites  with  deciduous
cover  than  in  sites  with  coniferous forest cover. Flowering
plants tended to be more abundant and robust  at  low  elevation
meadows,  while  seedlings and juveniles were disproportionately
represented at high elevation meadows. Decreased  juvenile  suc-
cess  in  the low-elevation meadows may be related to relatively
high litter from shrubs and grasses. Experimental data  indicate
that  appendages  on  the  bulbs,  which  persist as remnants of
previous years' bulbs,  can  act  as  vegetative  propagules  if
mechanically  separated.  In addition, both bulbs and appendages
were successfully transplanted over a  two-year  period  from  a
subalpine  meadow to a very different habitat type, 1500 m lower
in elevation.

The ethnobotanical review confirms that the species  was  tradi-
tionally a highly significant root resource for northern plateau
peoples, particularly the Secwepemc and Nlaka'pamux peoples, for
probably  thousands  of  years. These peoples collected, stored,
and traded large quantities of the bulbs,  and  the  traditional
processing strategies generally included drying and pit-cooking.
People  developed  a  detailed  ecological  understanding of the
species, and practiced active resource management strategies.

Nutritional results indicated a carbohydrate-rich food resource,
with the main storage carbohydrate  consisting  of  starch  (not
inulin  or  other  fructan)  through most of the growing season.
There are significant quantities of  sugars  (including  fructo-
oligosaccharides)  present  at  the  beginning  of  the  growing
season, but starch  increases  rapidly  and  peaks  (along  with
overall  food value) in the early (green) fruit stage of growth.
For bulbs at  the  fruiting  stage,  drying  markedly  increases
sugars  in  the  bulbs relative to starch, while pit-cooking the
dried bulbs  does  not  have  significant  effects  on  relative
amounts  of  carbohydrates.  However,  pit-cooking has important
qualitative effects  on  the  appearance,  taste,  and  possibly
storage  properties  of  the  bulbs,  as well as representing an
efficient processing strategy.

I argue that traditional harvesting  and  management  strategies
practiced  by First Nations people (including tilling, thinning,
replanting of appendages, and landscape burning) mean  that  the
ecology  and  ethnobotany of the species cannot be considered in
isolation. Based on previous ecological and ethnoecological work
on this and similar species, it seems likely that yellow glacier
lily is adapted to  a  periodic,  moderate  disturbance  regime,
which traditional practices may have mimicked or enhanced.

Loewen,  D.C.  1998. Ecological, Ethnobotanical, and Nutritional
   Aspects of Yellow Glacier  Lily,  _Erythronium  grandiflorum_
   Pursh  (Liliaceae),  in Western Canada. M.Sc. Thesis, Depart-
   ment of Biology, University of Victoria,  Victoria,  BC.  214
   pages.

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