Bryological and Lichenological Section/ABLS
Eppley, Sarah , Taylor, Philip , Linley, Jesson .
Self-fertilisation in mosses: a comparison of heterozygote deficiency between species with combined versus separate sexes.
SELF-FERTILISATION is a key difference of adaptive significance between species with combined versus separate sexes. In haploid-dominant species such as mosses and ferns, species with either combined or separate sexes (monoicous and dioicous, respectively) have the potential to self-fertilise (intergametophytic selfing), but combined sexes allows for an additional mechanism of selfing (intragametophytic selfing). We used allozyme electrophoresis to estimate deviations from expected levels of heterozygosity under Hardy-Weinberg equilibrium to infer selfing rates in ten moss species from 36 New Zealand populations. We found that while there were deficiencies of heterozygotes compared to expectation in both monoicous and dioicous mosses, monoicous species had significantly higher levels of heterozygote deficiency than dioicous species (FIS = 0.89 ± 0.12 and 0.41 ± 0.11, respectively). Estimated selfing rates suggest that selfing occurs frequently in monoicous populations, and rarely in dioicous populations. However, in two dioicous species (Polytrichadelphus magellanicus and Breutelia pendula), we found significant indications of mixed mating or biparental inbreeding in a handful of populations. These data provide the first analysis of heterozygote deficiency and selfing among haploid-dominant species with breeding system variation, and we discuss our results with respect to the consequences of inbreeding depression and the evolution of breeding systems.
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1 - Portland State University, Biology Department, Po Box 751, Portland, Oregon, 97207-0751, USA
2 - Victoria University of Wellington, School of Biological Sciences, P. O. Box 600, Wellington, , New Zealand
Presentation Type: Oral Paper:Papers for Sections
Location: 304/Bell Memorial Union
Date: Monday, July 31st, 2006
Time: 3:45 PM