December 16th, 1994
To: Plant Virologists
From: Agriculture Canada, Pacific Agriculture Research Centre,
Vancouver (formerly Vancouver Research Station)
Agriculture and Agri-Food Canada's Pacific Agriculture Research
Centre (Vancouver) has just completed the rejuvenation of the
Station's collection which now comprises approximately 100 plant
viruses from 350 different isolates. We would like to make this
collection available to those interested in obtaining viruses for
research purposes. A complete inventory of the collection has
been compiled on a database and is available upon request.
Anyone interested in obtaining isolates from this collection
should consider phytosanitary regulations pertaining to the
importation of plant pathogens to avoid delays in shipping.
Inquiries/requests should be directed to:
Dr. Chris French
E-mail address: FRENCH at PARGVA.AGR.CA
Summary of PARC-Vancouver Plant Virus Collection.
Sources of Viruses.
Approximately 350 isolates of plant viruses are located in the
collection located in the walk-in freezer (-20oC) on the main
floor of the Pacific Agricultural Research Centre (PARC),
Vancouver. The collection consists primarily of those viruses
which were successfully resurrected from two existing collections
held within the station. Both of these contributing collections
have existed since the early 1970's with new samples continually
being added over the years so that as of 1994 there was a
combined total of approximately 650 isolates. Unfortunately, due
to the inevitable degradation of most viruses in storage for
several years, many of these isolates could not be recovered and
added to the new collection. Overall, there has been roughly a
50% recovery rate of the isolates from these collections in which
the average length of time in storage is about 15 years.
Generally speaking the recovery rate rises as the length of time
in storage decreases, however some virus groups have proven to be
almost 100% recoverable after over 20 years, especially after
freezedrying. Other groups proved difficult to recover after a
very short time in cold storage. Other sources of isolates for
the new collection include PARC's visiting scientists and
institutions such as the American Type Culture Collection.
Breakdown of Viruses by group.
Alfalfa Mosaic Group.........3 Ilar........................3
Bromo.......................10 Luteo.......................4
Carmo........................7 Necro.......................6
Carla.......................10 Nepo.......................23
Caulimo......................3 Potex......................25
Clostero.....................1 Poty.......................68
Como.........................3 Sobemo.....................20
Cucumo......................16 Tobamo.....................24
Diantho.....................42 Tobra.......................3
Faba.........................1 Tombus......................5
Gemini.......................2 Tospo.......................5
Hordei.......................6 Tymo........................1
Idaeo........................1 Unknown....................45
Geographic origins of isolates.
British Columbia.............30
Rest of Canada...............8
U.S.A. .....................27
Central & South America......11
Europe.......................9
Asia.........................2
Africa.......................32
Australia....................1
Quality Control.
1. Virus identity.
Electron microscopy, host range analysis, and/or, when
antiserum is available, serologEnzyme-linked Immunosorbant Assaimmuno-microscopy
Local lesion isolation over several generations, host range
analysis, electron microscopy, and/or ELISA are techniques which
have been employed where possible to try and minimize the
possibility of mixed infection in samples contained within the
collection. None of these techniques is completely foolproof and
therefore culture purity of isolates within the collection is not
guaranteed.
3. Storage method.
To maximize long-term viability of new additions to the
collection all isolates are ground to a fine powder using liquid
nitrogen in a mortar and pestle and immediately freezedried until
completely dry. Following this, the dry powder is added to 2ml
cryovials filled 1/3 with 6 - 18 mesh, colour-indicating silica
gel desiccant and a small amount of gauze. The sealed tubes are
colour-coded and then put in a plastic box and frozen at -20oC.
4. Testing after processing.
A small amount of the freezedried powder is retained for
testing bioactivity following freezedrying.
Compliments of the season from the virologists at Vancouver to
all our colleagues around the world!