Agaricus germ plasm program

Richard W. Kerrigan rwk at
Tue Mar 21 08:02:42 EST 1995

This informational posting may be freely (if faithfully) 
reproduced.  Please forward a copy of any re-posting or print 
publication to RWK.  (rwk at

                                                   1 March 1995
     The first seven years of the AGARICUS RESOURCE PROGRAM

The Agaricus Resource Program (ARP) was started in 1988 to 
encourage the discovery, acquisition, preservation, 
characterization, and distribution of novel germ plasm of 
_Agaricus bisporus_, the cultivated button mushroom, and other 
closely related species of _Agaricus_.  The program has been 
funded annually by ten to twelve commercial, quasi-governmental 
or government laboratories in the United States, the United 
Kingdom, the Netherlands, Switzerland, France, Italy, and China.  
These funds are primarily used to provide bounties, an incentive 
to motivate the collection and donation of viable samples of wild 
germ plasm to the ARP.  Bounties can range as high as $100 for a 
genetically unique new isolate of _A. bisporus_.  Collectors are 
also reimbursed for their costs.  More details are given below.

While 'Dollars-for-Diversity' may strike some as crass, it has 
proven to be the most cost-effective means of overcoming the 
severe genetic bottleneck afflicting resource collections of this 
species.  In the 1980s there appear to have been fewer than 20 
independent lines of _A. bisporus_ in mainstream culture 
collections worldwide, including those of commercial 
laboratories.  This may well be a record low for any commercially 
important crop species.  To judge from many herbaria and culture 
collections, this species has apparently been disdained by 
serious mushroom collectors (for speculation on possible reasons, 
see Kerrigan, R. W. 1993.  New prospects for Agaricus bisporus 
strain improvement.  Rept. Tottori Mycol. Inst. 31:188-200).

As for money, the ARP bounty provisions are intended to be of 
potential assistance to students and practitioners of mycology, 
including those in developing countries.  Bounties may always be 
declined by those primarily interested in contributing to 
scientific and agronomic progress.

Anyone with sufficient knowledge of mushroom taxonomy (an ability 
to recognize different species of _Agaricus_) may contribute 
samples to the ARP, either under the bounty program (assumed) or 
as gifts (if stated).  Any person or organization may become a 
sponsor of the ARP, receive the annual germ plasm distributions 
with an essentially unrestricted right to use the material 
scientifically or commercially, and receive as well updates on 
what is known about the genotypes and field origins of each 
isolate.  Details are given below.  

The ARP was originally known as the Agaricus Recovery Program.


Number of samples received:             206

Number of viable A. bisporus:           157

Number of definite novel genotypes:      58

Number of genotypes known/duplicated:    19

Number of samples distributed:          174

Number of countries sampled:              9

Number of continents sampled:             4

Number of collectors responding:         32   (see thanks below)

Number of new populations discovered:     1

Number of new taxa published:             1

Number of publications enabled:           5   (see list below)

Number of bounties paid:                122

Amount of bounties paid out:         $ 5750.00

Amount of costs reimbursed:          $ 1272.00

Herbarium support provided:          $  600.00

** Goal for new samples received:       300 in 2000

It is difficult to quantitatively summarize the genetic novelty 
obtained via the ARP.  Numerous new alleles at nuclear marker 
loci, and several new mtDNA haplotypes, have been found in the 
collection.  Ten of fourteen known mating types are available 
only from ARP strains (P. Callac, pers. comm.).

My sincere thanks to the following individuals, whose effort have 
placed collections in the ARP: A. Martyn Ainsworth, B. W. Beebe, 
Jerry B. Burnett, Laverne Chariton, James E. Cunningham, Vincent 
Demoulin, Dennis E. Desjardin, Royce Harvey, P. Heinemann, Jin 
Jiankang, Robert G. Kenneth, Martha Kingsbury, Lavina MacCubbin, 
(Hanne)lore Lebrecht, Pavel Lizon, Albert Marchal, Shea Moss, J. 
J. Muchovej, Jack Parkin, Bruce Prior, Dana Richter, Clark T. 
Rogerson, Robert Sellers, Myron L. Smith, Fred Stevens, 
Christopher Thayer, Thomas J. Volk, Glenn Walker, Wang Fang-hui, 
Lynn Williams, Nathan J. Wilson, Henry Young, and Kitt Scates.  

Thanks also to Doris A. Anders, Stephanie Digby, Robert W. 
Fisher, Lenhart Gidholm, Hans Kothe, David Porter, Richard Scrase 
for interest and/or effort.  

Special thanks to Ian K. Ross, James B. Anderson, Paul A. Horgen, 
and Mark Spear & Sylvan Spawn Laboratory for providing overhead 
support to the ARP along the way.

AND, without the sponsorship of the following organizations, 
operation of the ARP would not have been possible: Sylvan Spawn 
Laboratory Inc., Amycel/Spawn Mate, Campbell's Fresh Inc., 
Lambert Spawn Co. Inc., J. B. Swayne Spawn Co., Proefstation 
voor de Champignoncultuur - Horst, Hauser/Sylvan Pilz AG, Somycel 
S.A., Centre Technique du Champignon / INRA CR Bordeaux, Royale 
Champignon, Italspawn, Fujian Research Institute of Light 
Industry - Fuzhou, Penwest Foods Co., Horticultural Research 
International - Wellesbourne. 


Kerrigan, R. W., P. A. Horgen, and J. B. Anderson  1993.  The 
  California population of Agaricus bisporus comprises at least 
  two ancestral elements.  Sys. Bot. 18:123-136.

Wang, Z. S., J. H. Liao, F. G. Li, Z. N. Chi, and H. C. Wang  
  1993.  Identification of field-collected isolates of Agaricus 
  bisporus.  Micol. Neotrop. Apl. 6:127-136.

Callac, P., C. Billette, M. Imbernon, and R. W. Kerrigan  1993.  
  Morphological, genetic, and interfertility analyses reveal a 
  novel, tetrasporic variety of Agaricus bisporus from the 
  sonoran desert of California.  Mycologia 85:835-851.

Kerrigan, R. W., M. Imbernon, P. Callac, C. Billette, and J.-M. 
  Olivier  1994.  The heterothallic life cycle of Agaricus 
  bisporus var. burnettii and the inheritance of its tetrasporic 
  trait.  Exp. Mycol. 18:193-210.

Kerrigan, R. W.  (in press)  Global genetic resources for 
  Agaricus breeding and cultivation.  Can. J. Bot.

[Four other publications on ARP strains were submitted as of 
March '95.  Other projects in various laboratories are being 
readied for publication.]


Sonnenberg, A. S. M., C. Gere, and L. J. L. D. Van Griensven  
1994.  Mitochondria in a wild collection of the [white] button 
mushroom Agaricus bisporus.  IMC V, Vancouver.

Robison, M., and P. A. Horgen  1994.  RNA polymerase-like 
sequences in the mitochondria of Agaricus species.  IMC V, 


As part of a program to recover, characterize, and preserve wild 
germ plasm of the cultivated "button mushroom" species Agaricus 
bisporus (sometimes called A. brunnescens), a bounty of up to 
$100.00 (US) is offered for each living sample of a unique wild 
collection which is forwarded to the address below.  The reward 
program has long-term funding commitments from a group of 
corporate mushroom spawn producers.  The germ plasm recovered by 
this effort will be used in evolutionary studies on the origin 
and diversity of A. bisporus, and will be conserved for future 
controlled breeding programs leading to improved cultivars. 

Each A. bisporus bounty will be proportional to the genetic 
uniqueness of the isolate, scored for several genetic markers 
(allozymes and RFLPs).  Certain related species are also sought.  
Full collection data are expected.  The bounty scale is:

     A new combination of known alleles across loci     ... $ 25
     A new combination of alleles at one or more loci   ... $ 50
     A new allele at one or more loci                   ... $100
     A previously-recovered genotype                    ... $  0
     Closely related species such as A. subfloccosus or 
      A. subperonatus (not A. campestris or A. bitorquis).. $0-100
      (depending on novelty and origin)
     NOTE: in the event that genetic analysis is not complete 
      within one year of contribution, an upgradable bounty of
      $25.00 will be paid to the collector.

Sporocarp tissue-cultures, on agar slants, padded inside of a 
crush-proof box, are the preferred form of sample.  They should 
be sent by air mail (or express post or courier, during hot 
weather), marked "Urgent - Perishable.  Keep away from heat.  Do 
not freeze."  Any customs declaration should state "Research 
culture of edible Agaricus mushroom on sterile agar medium."  

Clean spore prints are the next best option.  These should be air 
dried (no or little heat).  Aluminum foil is ideal for such 
prints.  With old sporocarps, remove several gills and wrap the 
gills in facial tissue-paper ('Kleenex').  Prints and gills may 
be air-mailed.  

If necessary, ARP will accept fresh, sound sporocarps from US 
locations.  Call first: weekdays: 412-352-1521; else (8AM-9PM 
EST): 412-297-5844

When available, voucher specimens should be dried, boxed and sent 
later by surface post (Declared Value for US Customs = $0), 
and/or deposited in a recognized herbarium.  All materials should 
normally be sent to:

                    Agaricus Resource Program
                    Attn. Dr. R. W. Kerrigan 
                    RD #1 Box 461
                    Worthington, PA  16262  USA

During very hot or very cold weather please call before sending 
live biological materials, in case special delivery arrangements 
need to be made.  Costs of sending samples will be reimbursed 
promptly.  Bounties will be distributed annually, following 
genetic characterization of isolates.  I encourage anyone who 
finds A. bisporus growing away from sites of commercial 
cultivation to participate in this effort.  Thank you.

Richard W. Kerrigan, Ph.D.                   Revised: March, 1995


The Agaricus Resource Program (ARP) was initiated in August, 1988 
as an independent (non-institutional), not-for-profit service 
program.  The objectives of the ARP are to promote the discovery, 
acquisition, conservation, distribution, and characterization of 
wild germ plasm of Agaricus bisporus and very closely related 
species.  Acquisition is promoted by an international publicity 
campaign aimed at professional, amateur, and student field 
mycologists.  Incentive for contributions of field samples is 
augmented by the offer of bounties of up to US$ 100.00 on 
authentic, novel isolates.  Genetic novelty, as assessed by 
genotypic characterization at several well-studied loci, 
determines the size of each bounty.

Any organization or individual may become a sponsor of the ARP.  
Sponsorship is expected of each participating, independent 
organization; there are no "umbrella sponsors" such as national 
organizations.  Each sponsor annually remits an equal share of 
the projected costs of ARP operation for that year.  
Participation fees are set by the ARP based on the sponsorship 
support base, expenses incurred, bounties owed, and reserves 
necessary to sustain operation.  No salary is taken, nor is 
profit intended (however, under U.S. tax law monies not spent at 
year's end are treated as profit).  As of this date there are ten 
active sponsors of the ARP, and one host (Sylvan Spawn 
Laboratory, Inc.) which covers overhead.  Participation fees have 
ranged between $200 and $500 per year.  The ARP will normally 
attempt to broaden its sponsorship base before increasing cost 
shares.  Sponsors will be notified of any changes to current 
share amounts before April of each year.

Distribution of new isolates to sponsoring organizations occurs 
each Spring.  Replicate cultures are preserved in liquid nitrogen 
in the ARP collection.  Overseas sponsors pay an additional $15 
for express post service.  Sponsoring organizations are free to 
use ARP germ plasm as a strain development resource, without 
restraint.  However, the ARP expects that no sponsor will (1) 
attempt to establish proprietary rights over any particular ARP 
isolate, nor (2) redistribute ARP isolates without the written 
consent of the ARP.  ARP does intend that proprietary rights to 
strains selected from among inbred or crossbred progeny of ARP 
stocks, or rights to other inventions deriving from ARP germ 
plasm, may be asserted by originating sponsors, in the customary 
manner.  Publication of data on ARP isolates is encouraged; the 
ARP should be acknowledged as a source.

A report on the bounties paid and the genetic novelty, if any, 
detected in the screening program is conveyed to sponsors 
annually.  Sponsors joining after the first year may elect to 
receive prior-year sets by paying additional shares, 
or may propose more selective prior-year acquisitions.  ARP also 
exchanges isolates (generally on a novelty-weighted 1-for-1 
basis) with non-sponsors, and distributes such acquisitions 
annually to sponsors along with any gifts of isolates received.

The Agaricus Resource Program is meeting its goal of economically 
and efficiently developing a new germ plasm resource base for the 
commercial Agaricus strain development industry, while enabling 
scientific study of this natural resource.  Operation of ARP is 
intended to continue indefinitely.

Richard W. Kerrigan, Ph.D.       Revised and Updated: March, 1995

Richard W. Kerrigan, Research Department, Sylvan Spawn Laboratory, Inc.		
               1163 Winfield Rd., Cabot, PA  16032  USA
e-mail:	rwk at      phone: 412-352-1521      fax: 412-352-4062
	"Success has a thousand parents; failure is an orphan"

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