title: Testing the "one-log-one-genet" hypothesis: methodological challenges of population sampling for the Hawaiian wood-decay fungus Rhodocollybia laulaha.
abstract: We test our "one-log-one-genet" sampling method for the Hawaiian mushroom Rhodocollybia laulaha that posits all R. laulaha mushrooms collected from a single log represent a single genet. We also examine the potential expansion of single genets beyond the confines of one log and the temporal persistence of genets in nature. Finally, we estimate error rates in AFLP scoring. To our knowledge, this is one of few examinations of naturally occurring fungal genets in the tropics and a novel report of AFLP error rates in fungi. Forty-six mushrooms from seven logs were genotyped with the IGS1 locus, two microsatellite loci and 184 AFLP loci from three primer pair combinations. One hundred fifty-three mushroom collections representing the geographic range of R. laulaha were genotyped with the IGS1 and microsatellite loci. The probabilities of two genets sharing identical multilocus genotypes by chance (without actually being the same genet) were calculated for each genotype recovered. The data suggest that R. laulaha mushrooms from one log typically represent one genet, that genets might expand beyond the confines of a single log and that a single genet may persist in a collecting site for as much as 13 y. We offer initial evidence to support the "one-log-one genet" sampling method and the idea that R. laulaha vegetative expansion and persistence in nature might be common. In addition, we caution against exclusive use of AFLP loci for identifying fungal genets due to relatively high error rates in scoring.
authors.affiliation: Committee on Evolutionary Biology, University of Chicago, Chicago, Illinois 60637, Department of Botany, the Field Museum, Chicago, Illinois 60605, and Natural Science Department, State College of Florida, Bradenton, Florida 34207 keirlem@scf.edu.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Keirle
authors.affiliation: Department of Botany, the Field Museum, Chicago, Illinois 60605, and Department of Biology, Indiana University Northwest, Gary, Indiana 46408.
authors.forename: Peter G
authors.initials: PG
authors.lastname: Avis
authors.affiliation: Department of Biology, University of Hawaii, Hilo, Hawaii 96720.
authors.forename: Don E
authors.initials: DE
authors.lastname: Hemmes
authors.affiliation: Department of Botany, the Field Museum, Chicago, Illinois 60605, and Chicago Botanic Garden, Glencoe, Illinois 60022.
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Mueller
mesh_terms: D000363:Agaricales / Q000235:genetics* / Q000302:isolation & purification; D000483:Alleles; D054458:Amplified Fragment Length Polymorphism Analysis; D017931:DNA Primers / Q000235:genetics; D004271:DNA, Fungal / Q000235:genetics; D056426:Genetic Loci / Q000235:genetics; D005828:Genetics, Population; D005838:Genotype; D005843:Geography; D006254:Hawaii; D014934:Wood / Q000382:microbiology
chemical_list: D017931:DNA Primers; D004271:DNA, Fungal
keywords: AFLP; Rhodocollybia saprotroph; dikaryon; genet