HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Taylor, P. J. Articles by Jesson, L. K. Search for Related Content PubMed Articles by Taylor, P. J. Articles by Jesson, L. K. Agricola Articles by Taylor, P. J. Articles by Jesson, L. K.

Sporophytic inbreeding depression in mosses occurs in a species with separate sexes but not in a species with combined sexes¹

School of Biological Sciences, Victoria University of Wellington, P.O. Box 600, Wellington, New Zealand; Portland State University, Department of Biology, P.O. Box 751, Portland, Oregon, 97207-0751, USA; University of New Brunswick, Department of Biology, P.O. Bag Service 45111, Fredericton, New Brunswick, Canada E3B 6E1

ABSTRACT

Inbreeding depression is a critical factor countering the evolution of inbreeding and thus potentially shaping the evolution of plant sexual systems. Current theory predicts that inbreeding depression could have important evolutionary consequences, even in haploid-dominant organisms. To date, no data have been reported on inbreeding depression in moss species. Here, we present data on the magnitude of inbreeding depression in sporophytic traits of moss species with contrasting breeding systems. In Ceratodon purpureus (Ditrichaceae), a moss species with separate sexes, self-fertilizations between sibling gametophytes (intergametophytic selfing) significantly reduced fitness in two of four traits quantified, with seta length and capsule length having inbreeding coefficients significantly different from zero, resulting in a cumulative inbreeding depression that was also significantly greater than zero ( = 0.619 ± 0.076). In hermaphroditic Funaria hygrometrica (Funariaceae), there was no evidence of inbreeding depression in seta length, spore number, capsule mass, or capsule length resulting from sporophytes generated by self-fertilization within an individual (intragametophytic selfing), and cumulative inbreeding depression was also not different from zero ( = 0.038 ± 0.022). These results provide evidence that, despite haploid dominance, inbreeding depression can be expressed at the diploid stage in mosses and may have implications for the evolution and maintenance of combined versus separate sexes in mosses.

Key Words: Ceratodon purpureus • Funaria hygrometrica • gender dimorphism • inbreeding depression • moss • sexual system • sporophytes