[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
BEN # 203
BBBBB EEEEEE NN N ISSN 1188-603X
BB B EE NNN N
BBBBB EEEEE NN N N BOTANICAL
BB B EE NN NN ELECTRONIC
BBBBB EEEEEE NN N NEWS
No. 203 September 23, 1998
aceska@victoria.tc.ca Victoria, B.C.
-----------------------------------------------------------
Dr. A. Ceska, P.O.Box 8546, Victoria, B.C. Canada V8W 3S2
-----------------------------------------------------------
RARE PLANT SYMPOSIUM - UBC VANCOUVER, B.C. - OCTOBER 17, 1998
From: Patrick Williston <patrickw@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@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@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@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.
----------------------------------------------------------------
Submissions, subscriptions, etc.: aceska@victoria.tc.ca
BEN is archived at http://www.ou.edu/cas/botany-micro/ben/
________________________________________________________________