Reference Cultures

Botanical Code and Rules of Nomenclature

The need for type specimens is clearly stated in the Botanical Code and rules of nomenclature. Such specimens for glomeromycotan species consist primarily of spores preserved in a liquid medium (lactophenol, formalin, azide) and mounted permanently on glass slides. These spores often change their appearance and internal structure as a result of degradation in the normal process of senescence after death or because of preservative-induced changes over time. Many type specimens also do not reflect morphology of healthy spores because they were collected from field soils and were either in poor condition or parasitized. We have found the types to be most useful when they are compared against healthy specimens obtained from a living culture. Schüßler and Walker (2010) have erected some ex-epitypes (cultures with provenance to type material) to link morphological and sequence data sets. We make use of reference cultures (listed below) because they may or may not be linked to type material but still provide a living standard for comparative analyses.

Showing how Golomus caledonium UK301 is made up of 3 different Golomus caledonium DN986, HA692B and OR211A

Since all cultures of the 1200+ accessions in the collection are started with spores of the organism, species identity (named or unnamed) must be defined for taxonomic reasons as well as for record-keeping and database management. To accomplish this purpose, spores of each accession are compared to those of other putative species in the collection using the following protocol:

  • If the organism has one or more unique characters, it is established as a reference culture for an established or a new species.
  • The reference culture is assigned a Latin binomial name if it can be linked definitively to a named species by the following criteria:
  1. Shared features with a type specimen in good structural condition.
  2. Close match with details of a published description or redescription.
  3. Verification in disputed or tentative cases with identifications made by authors of protologues or other taxonomists having experience with the species in question.
  4. An author of a prologue or collaborating with authors of a species.
  • One or more of these criteria have been used to ascertain the reference cultures now recognized in INVAM and listed in the table below. For reference culture that could not be linked to a classified species, then this accession was assigned a genus name (based on well-established morphological criteria) and a numerical code based on database record number as a temporary specific epithet. All pertinent accessions with the same suite of traits as those of the reference culture were grouped together. This grouping process occurred whether or not species were named.

Starred reference species are not available for distribution for various reasons. Some species in the collection are not listed here because not enough criteria are met at this time to assign names with confidence.

Reference Cultures of Species in the Collection
* A. capsicula NC1684
A. cavernata FL736B2, 3
A. colombiana FL1841, 2, 3
A. contigua (ined.) WV109B4
A. delicata AZ6611, 2
* A. denticulata CL1391, 2
* A. excavata CU1211
A. foveata CR3151, 2
A. kentinensis TW111A1, 2, 3
A. koskei WV7362, 3
A. lacunosa WV6134
A. laevis AU2111, 2
A.longula CL3722, 3
A. mellea BR9832, 3
A. morrowiae CL552, 3
*A. rehmii BR2371, 2
A. scrobiculata BR9841, 2
A. tuberculata VZ103E1, 2, 3
Am. leptoticha FL1841, 2, 3
Am. gerdemannii MT1061, 2, 3
Ar. trappei AU2191, 2
Ar. schenckii CL3831, 2, 3
C. pellucida FL9661, 2, 3
C. candidum NC268A3, 4
C. claroideum SC1861, 2
C. etunicatum NE108A1, 2
C. fragilistratum DN9881, 2
C. lamellosum ON3931, 2, 3
C. luteum SA1124
D. nigra NC1821, 2, 3
D. erythropa MA453B1, 2, 3
D. heterogama IL2031, 2, 3
* D. rubra BR2114
D. eburnea AZ420A1, 2
* D. insculpta PL1213
D. globifera FL327B2, 3
D. spurca HA5671, 2, 3
D. tortuosa JA301B1, 2
D. epigaea IT1041, 2, 3
E. infrequens CA2031, 2
F. caledonius UK3011, 2
F. coronatus AU2022, 3
F. geosporus NE2021, 2, 3
F. monosporus IT1021, 2
F. mosseae UK1151, 2
F. verruculosus PL1172, 3
Gi. albida BR2141, 2
Gi candida BEG171
Gi. decipiens AU1022, 3
Gi. gigantea VA105C2, 3
Gi. margarita WV205A2, 3
Gi. rosea FL1052, 3
* G. clavisporum KS8954
G. microaggregatum AZ2431, 2
* G. pustulatum BR606A1, 2
P. brasilianum BR1051, 2
P. occultum IA7021, 2
P. mirificum (ined.) MD2144
R. aggregatus HO1024
R. clarus FL2392, 3
R. diaphanus WV579B2, 3
R. intraradices FL2081, 2, 3
R. manihotis FL8791, 2
R. sinuosus MD1261, 2
S. calospora AU2121, 2, 3
S. dipurpurascens WV9304
* S. cerradensis BR1033, 4
* S. scutata BR2431, 2, 4
S. constrictum KS8901, 2
S. deserticola CA1132, 3
S. viscosum MD2151, 2
R. castanea BEG11, 2, 3
R. gregaria BR2391, 2, 3
R. coralloidea CA2601, 2, 3
R. fulgida VA103B1, 2, 3
R. persica MA461A1, 2, 3
R. reticulata CL7562, 3
R. verrucosa VA105B1, 2, 3