Molecular Markers Reveal Cryptic Species Within Polytrichum commune (Common Hair-Cap Moss)

Abstract

Based on morphological characters only, the taxonomy of the moss genus Polytrichum has still not been fully resolved. Application of molecular techniques might clarify some of these problems. Within P. commune s.l., the taxonomic status of several varieties, e.g., P. commune var. commune and P. commune var. uliginosum, is still debated. This study uses allozyme electrophoresis to show that there are two distinct allozyme multi-locus genotypes within our P. commune samples. These two multi-locus genotypes coincide with both differences in morphology and differences in habitat association. This division is corroborated by observations from different Danish and Dutch populations. Based on these results, in connection with a genetic comparison of the two infraspecific taxa of P. commune s.l. with a related species P. formosum, we argue that P. commune var. commune and P. commune var. uliginosum are two genetically distinct entities with fixed morphological differences and a considerable niche differentiation. They should, therefore, be regarded as two distinct species: P. commune and P. uliginosum.

Key words

Allozymes - cryptic species - genetic identity - Polytrichum commune - Polytrichum commune var. commune - Polytrichum commune var. uliginosum - taxonomy

References

• 01 Anderson,  L. E.. (1963);  Modern species concepts: mosses.  The Bryologist. 66 107-119
• 02 Avise,  J. C.. (1994) Molecular markers, natural history and evolution. New York; Chapman & Hall
• 03 Crawford,  D. J.. (1983) Phylogenetic and systematic inferences from electrophoretic studies. Isozymes in plant genetics and breeding, Part A. Tanksley, S. D. and Orton, T. J., eds. New York; Elseviers Science Publishers pp. 257-287
• 04 Cronberg,  N.. (1998);  Population structure and interspecific differentiation of the peat moss sister species Sphagnum rubellum and S. capillifolium (Sphagnaceae) in northern Europe.  Plant Systematics and Evolution. 209 139-158
• 05 Crum,  H. A.. (1972);  The geographic origin of the mosses of North America's eastern deciduous forest.  Journal of the Hattori Botanical Laboratory. 35 269-298
• 06 Crum,  H. A., and Anderson,  L. E.. (1981) Mosses of eastern North America, Vol. 2. New York; Columbia University Press
• 07 Derda,  G. S., and Wyatt,  R.. (1990);  Genetic variation in the common hair-cap moss, Polytrichum commune. .  Systematic Botany. 15 592-605
• 08 De Vries,  A.,, Van Zanten,  B. O.,, and Van Dijk,  H.. (1983);  Genetic variation within and between populations of two species of Racopilum (Racopilaceae, Bryopsida).  Lindbergia. 9 73-80
• 09 De Vries,  A.,, Bramer,  J. P. J.,, Van Zanten,  B. O.,, Hofman,  A.,, and Bijlsma,  R.. (1989);  Allozyme variation in four Racopilum species including the polyploid R. tomentosum. .  Lindbergia. 15 47-49
• 10 Hampe,  E.. (1839);  Relation über die von dem Reisenden C. Beyrich auf seiner letzten Reise in Nordamerika gesammelten Laubmoose.  Linnaea. 13 39-48
• 11 Hedwig,  J.. (1801) Species muscorum frondosorum. Lipsiae. 
• 12 Hofman,  A.. (1988);  A preliminary survey of allozyme variation in the genus Plagiothecium (Plagiotheciaceae, Bryopsida).  Journal of the Hattori Botanical Laboratory. 64 143-150
• 13 Lawton,  E.. (1971) Moss flora of the pacific Northwest. Nichinan; Hattori Botanical Laboratory
• 14 Longton,  R. E.. (1976);  Reproductive biology and evolutionary potential in bryophytes.  Journal of the Hattori Botanical Laboratory. 41 205-223
• 15 Margadant,  W. D., and During,  H. J.. (1982) Beknopte flora van Nederlandse blad- en levermossen. Zutphen; Thieme
• 16 Michaux,  A.. (1803) Flora Boreali-Americana, sistens caracteres plantarum quas in America septentrionalii collegit et detexit, tab. ornata. Parisiis et Argentorati; André Michaux, II.
• 17 Möller,  E. M.,, Bahnweg,  G.,, Sandermann,  H.,, and Geiger,  H. H.. (1992);  A simple and efficient protocol for isolation of high molecular weight DNA from filamentous fungi, fruit bodies, and infected tissues.  Nucleic Acids Research. 20 6115-6116
• 18 Nei,  M.. (1987) Molecular evolutionary genetics. New York; Columbia University Press
• 19 Nyholm,  E.. (1969) Illustrated moss flora of Fennoscandia, II. Musci. Lund; Gleerup
• 20 Schriebl,  A.. (1982);  Culture experiments on the moss genus Polytrichum. .  Journal of the Hattori Botanical Laboratory. 53 157-158
• 21 Schriebl,  A.. (1991);  Experimentelle Studien über die Laubmoosgattung Polytrichum. .  Carinthia II. 181 461-506
• 22 Smith,  A. J. E.. (1978) The moss flora of Britain and Ireland. Cambridge; Cambridge University Press
• 23 Smith,  G. L.. (1971);  Conspectus of the genera of Polytrichaceae.  Memoirs of the New York Botanical Garden. 21 1-83
• 24 Stoneburner,  A.,, Wyatt,  R.,, and Odrzykoski,  I. J.. (1991);  Application of enzyme electrophoresis to bryophyte systematics and population biology.  Advances in Bryology. 4 1-27
• 25 Swofford,  D. L., and Selander,  R. B.. (1981) Biosys-I, a computer program for the analysis of allelic variation in genetics, User's manual. Urbana; University of Illinois
• 26 Sytsma,  K. J., and Gottlieb,  L. D.. (1986);  Chloroplast DNA evidence for the origin of the genus Heterogaura from a species of Clarkia (Onagraceae).  Proceedings of the National Academy of Sciences of the USA. 83 5554-5557
• 27 Touw,  A., and Rubers,  W. V.. (1989) De Nederlandse Bladmossen. Utrecht; Stichting Uitgeverij van de Koninklijke Nederlandse Natuurhistorische Vereniging
• 28 Van de Ven,  W. T. G., and McNicol,  R. J.. (1995);  The use of RAPD markers for the identification of Sitka spruce (Picea sitchensis) clones.  Heredity. 75 126-132
• 29 Van de Zande,  L., and Bijlsma,  R.. (1995);  Limitations of the RAPD technique in phylogeny reconstructions in Drosophila. .  Journal of Evolutionary Biology. 8 645-656
• 30 Van Treuren,  R.,, Bijlsma,  R.,, Van Delden,  W.,, and Ouborg,  N. J.. (1991);  The significance of genetic erosion in the process of extinction. I. Genetic differentiation in Salvia pratensis and Scabiosa columbaria in relation to population size.  Heredity. 66 181-189
• 31 Van Zanten,  B. O., and Hofman,  A.. (1994);  On the possible origin and taxonomic status of Hypnum heseleri Ando & Higuchi.  Journal of the Hattori Botanical Laboratory. 75 107-117
• 32 Wallroth,  F. G.. (1831) Flora cryptogamica Germaniae. Norimbergae. 
• 33 Wyatt,  R.. (1985);  Species concepts in bryophytes: input from population biology.  The Bryologist. 88 182-189
• 34 Wyatt,  R., and Derda,  G. S.. (1997);  Population biology of the Polytrichaceae.  Advances in Bryology. 6 265-296
• 35 Wyatt,  R.,, Odrzykoski,  I. J.,, and Stoneburner,  A.. (1989 a);  High levels of genetic variability in the haploid moss Plagiomnium ciliare. .  Evolution. 43 1085-1096
• 36 Wyatt,  R.,, Odrzykoski,  I. J.,, and Stoneburner,  A.. (1992);  Isozyme evidence of reticulate evolution in mosses: Plagiomnium medium is an allopolyploid of P. ellipticum × P. insigne. .  Systematic Botany. 17 532-550
• 37 Wyatt,  R.,, Stoneburner,  A.,, and Odrzykoski,  I. J.. (1989 b) Bryophyte isozymes: systematic and evolutionary implications. Isozymes in plant biology. Soltis, D. E. and Soltis, P. S., eds. Portland; Dioscorides Press pp. 221-240
• 38 Yamazaki,  T.. (1981);  Genic variabilities in natural population of haploid plant, Conocephalum conicum. I. The amount of heterozygosity.  Japanese Journal of Genetics. 56 373-383
• 39 Yamazaki,  T.. (1984);  The amount of polymorphism and genetic differentiation in natural populations of the haploid liverwort Conocephalum conicum. .  Japanese Journal of Genetics. 59 133-139
• 40 Van der Velde,  M., and Bijlsma,  R.. (2000);  Amount and structure of intra- and interspecific genetic variation in the moss genus Polytrichum. .  Heredity. 85 in press

Section Editor: F. Salamini