BEN # 259
Adolf Ceska
aceska at victoria.tc.ca
Tue Oct 24 04:52:46 EST 2000
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No. 259 October 24, 2000
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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_PTEROSPORA ANDROMEDEA_: MORPHOLOGICAL AND MOLECULAR ASSESSMENT
OF MYCORRHIZAE FROM PLANTS GROWING IN A CONIFEROUS FOREST
ECOSYSTEM IN CENTRAL BRITISH COLUMBIA
From: Catherall J.M., H.B. Massicotte, B.W. Young,
L.E. Tackaberry, & K.N. Egger
c/o Jen Catherall <cather0 at hotmail.com>
[This is a summary from a poster presented at the Canadian
Botanical Association Annual Meeting in London, Ontario, in June
2000. The poster that I produced received the Ian and Sylvia
Taylor Award for best student poster. This project is part of my
undergraduate thesis project that is still underway and will be
completed in June 2001. - Jen Catherall, University of Northern
British Columbia, Prince George, BC, Canada V2N 4Z9]
_Pterospora andromedea_ Nutt. (pinedrops; Ericaceae, Monotro-
poideae) is a curiously impressive epiparasitic species that has
attracted numerous ecological and morphological investigations.
This achlorophyllous species, the only member of its genus, has
a complex mode of nutrition, receiving photosynthates from
neighbouring trees via shared fungi.
To explore the mycorrhizal associations within its northern
range, plants were sampled from 4 sub-boreal forest locations
near Prince George, BC. Site-associated trees varied but in-
cluded _Pinus contorta_, _Picea_ spp., and _Populus tremulo-
ides_. A minimum of 5 root clusters per location were collected
over 10 weeks (June to August, 1999). Both epigeous and
hypogeous sporocarps of the _Suillus_-_Boletus_-_Rhizopogon_
group found within close vicinity of the sampled plants were
also collected.
Mycorrhizae were assessed morphologically (light microscopy) and
by molecular analysis (PCR-RFLP and DNA sequencing). All methods
showed that individual root clusters (often several hundred
tips) consisted of fungal monocultures. Only one fungal mor-
photype was characterized for all tips; this mycorrhizae
produced a white mantle (sometimes mauve to darker blue), short
bristle-like verrucose cystidia, no clamps, and rhizomorphs.
The three restriction endonucleases (AluI, HinfI and RsaI) used
to cleave the PCR product for RFLP analysis showed no variation
between the fragment patterns for the samples. DNA sequencing of
the 5' end of the 28S region of the ribosomal RNA gene of the
_Pterospora andromedea_ and _Pinus contorta_ root tips, as well
as the hypogeous sporocarp, resulted in a highly similar partial
sequence alignment. Submission of the fungal sequences to Gen-
Bank suggests that these fungi closely resemble _Rhizopogon
subcaerulescens_ (I.D. #AF071534).
These data are still being analysed but early results from the
investigation support findings by Cullings et al. (1996).
_Pterospora andromedea_ appears to be uniquely specialized with
the _Rhizopogon subcaerulescens_ group across widely disparate
regions of North America, including its northern range. This
study also provides increased evidence into the probable ec-
tomycorrhizal linkage between _Pterospora andromedea_, _Pinus
contorta_ and _Rhizopogon subcaerulescens_. The mycorrhizal
specialization exhibited by _Pterospora andromedea_ may directly
impact the ability of this mycoheterotrophic plant to link with
its autotrophic host(s) and ultimately its survival in changing
forest ecosystems.
Reference:
Cullings, K. W., T.M. Szaro, & T.D. Bruns. 1996. Evolution of
extreme specialization within a lineage of ectomycorrhizal
epiparasites. Nature 379(6560): 63-67.
PROTECTION OF WETLANDS IN CANADA
From: Clay Rubec [Clay.Rubec at ec.gc.ca]
Wetlands in Canada are managed very differently than in other
developed nations, particularly in the United States. While
American experience has been strongly oriented to a regulated
permitting system and protection based on litigation, Canadian
federal and provincial management to date has a strong focus on
voluntary, non-regulatory action supported by policy based on
sound scientific advice. The Government of Canada and four
provinces (Alberta, Saskatchewan, Manitoba and Ontario) have
adopted wetland management policies articulating goals and
strategies for cooperation and stewardship. This is not to say
regulatory actions are also not in use, in Ontario and Prince
Edward Island for example provincial law regulates the use and
development in and around wetlands.
In all provinces and territories in Canada a wide range of
wetland conservation programs and other regulatory tools are
also in place that assist in protecting wetlands and encouraging
an overall no net loss perspective. These are summarized in a
recent publication entitled "_Wetlands and Government_" avail-
able from the North American Wetland Conservation Council
(Canada), Suite 200, 1750 Courtwood Cres., Ottawa, ON K2C 2B5
(e-mail: nawcc at igs.ca) or on line at http://www.cws-scf.ec.gc.ca
- see publications section of this Environment Canada web site).
Why this voluntary-policy approach? Experience in Canada sug-
gests organizations feel there are circumstances where a regu-
lated system is appropriate as no other options exist. In some
geographic areas (e.g., the Fraser Lowland and southeast On-
tario) too many wetlands are degraded and too few options for
voluntary action exist. However, in much of Canada a voluntary
stewardship approach offering landowner incentives and support
may be more effective. Despite over 20 years of costly, time
consuming litigation and regulation across the USA, wetlands are
still being lost. Canadians have benefitted from watching this
USA experience and seek a better more successful approach here.
A major difference also lies in the constitutional authorities
across the USA versus Canada. In the USA, the federal government
may regulate all wetlands over a minimum size using federal
water course protection legislation and other mechanisms. Small
wetlands and those not associated with federally regulated
waters are under state authority in most cases. Such is not the
case in Canada, where most wetlands as a provincial natural
resource are owned and managed under provincial jurisdiction.
Only wetlands on federal lands, and in the Northern Territories
generally lie under direct federal management. The federal
government has laid out its commitments for wetlands through the
Federal Policy on Wetland Conservation since 1991 and the Guide
for Federal Land Managers under this Policy (1996).
Contact: Clayton Rubec, A/Chief Habitat Conservation, Environ-
ment Canada, Ottawa, ON K1A 0H3.
BOOK REVIEW: BRYOPHYTE BIOLOGY
From: Wilf Schofield [wilfs at interchange.ubc.ca]
Shaw, A. Jonathan & Bernard Goffinet [eds.] 2000. Bryophyte
Biology. x+476 p., Cambridge University Press, Cambridge.
ISBN 0-521-66097-1 [hard cover] Price: US$100.00, ISBN 0-521-
66794-1 [soft cover] Price: US$35.95.
Available from:
Cambridge University Press
The Edinburgh Bldg., Cambridge CB2 2RU, United Kingdom
http://www.cup.cam.ac.uk
40 West 20th Street, New York, NY 10011-4211, USA
http://www.cup.org
This book presents a valuable summary of current knowledge of
selected aspects of bryophyte biology. It is an essential
reference for bryologists and invaluable to those pursuing
specialized topics in the biology of bryophytes. Few of the
contributors have attempted to write for a novice; most articles
are dense with specialized terminology. A glossary would have
helped all readers immeasurably.
The contributions include articles on anatomy , development, and
classification of hornworts (Renzaglia & Vaughn), morphology and
classification of the Marchantiophyta (Crandall-Stotler &
Stotler), morphology and classification of the mosses (Buck &
Goffinet), origin and phylogenetic relationships of the
bryophytes (Goffinet), chemical constituents and biochemistry
(Mues), molecular genetic studies of moss species (Cove), con-
trol of morphogenesis in bryophytes (Christianson), physiologi-
cal ecology (Proctor), mineral nutrition, substratum ecology,
and pollution (Bates), peatlands: ecosystems dominated by
bryophytes (Vitt), role of bryophyte-dominated ecosystems in the
global carbon budget (O'Neil), population ecology, population
genetics, and microevolution (Shaw), and bryogeography and
conservation of bryophytes (Tan & Pocs).
Illustrations are few and reproduction of half-tones is
generally poor, often resulting in grey blurred images.The
illustration of _Polytrichum piliferum_, for example, is so
blurred that it is impossible to determine the species, and
acrocarpy is not clearly represented because attachment of the
sporophytes is obscure; the illustrations for pleurocarpy are
highly successful.
It is disappointing to see, yet again the terms haplolepideous
and diplolepideous used when it is apparent that haplolepidous
and diplolepidous are meant.
In summary, this book contains extremely useful articles on the
current status of selected topics in bryology. It is probable
that the classification systems are premature, based on inade-
quate data; these systems will be vastly altered when those data
become available. Still, they represent useful summaries. As a
reference book for students who have had education in fundamen-
tal bryology, it will be highly useful, but for beginning stu-
dents, it is far too specialized.
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