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 HighWire Citing Articles via ISI Web of Science (6) Citing Articles via Google Scholar Google Scholar Articles by Delph, L. F. Search for Related Content PubMed Articles by Delph, L. F. Agricola Articles by Delph, L. F.

Testing for sex differences in biparental inbreeding and its consequences in a gynodioecious species¹

Department of Biology, Jordan Hall, 1001 East Third Street, Indiana University, Bloomington, Indiana 47405 USA

In many gynodioecious species cross-pollinated seeds from females outperform those from hermaphrodites. Using the gynodioecious alpine perennial Silene acaulis, I investigated whether this was the result of greater biparental inbreeding among hermaphrodites leading to greater biparental inbreeding depression. I also determined the influence of relatedness on progeny fitness. Experiments were performed using individuals from a site whose population structure and coefficient of inbreeding was known. In the first experiment, crosses were made on plants in the field to determine the effect of seven different crossing distances, plus selfing, on germination and early seedling survival and growth. Although selfed seeds died more often and grew slower than crossed seeds, the effect of crossing distance was negligible for all measured fitness traits, refuting the biparental inbreeding hypothesis as a mechanism to explain why seeds from hermaphrodites die more often than those from females. Nonetheless, cross-pollinated seeds from hermaphrodites did die more, indicating that another mechanism must be responsible. In the second experiment, the effect of different levels of inbreeding on germination and seedling survival was determined by growing seeds from experimental matings varying in relatedness. Inbreeding depression for a multiplicative fitness estimate was significant for all levels of inbreeding, suggesting that inbred individuals are unlikely to become established in the population and providing insight into the results of the first experiment. Alternative hypotheses are discussed to explain why seeds from hermaphrodites die more often, which together with the results of this study, suggest that the restoration of male function in hermaphrodites comes with a correlated cost to seedling survival.

Key Words: biparental inbreeding depression • Caryophyllaceae • crossing distance • hand pollination • Silene acaulis

This article has been cited by other articles:

				D. E. McCauley and M. F. Bailey Recent advances in the study of gynodioecy: the interface of theory and empiricism Ann. Bot., June 10, 2009; (2009) mcp141v1. [Abstract] [Full Text] [PDF]

				M. GLAETTLI, L. PESCATORE, and J. GOUDET Proximity-dependent Pollen Performance in Silene vulgaris Ann. Bot., August 1, 2006; 98(2): 431 - 437. [Abstract] [Full Text] [PDF]