The cost of realized sexual reproduction: Assessing patterns of reproductive allocation and sporophyte abortion in a desert moss

Lloyd R. Stark, Brent D. Mishler, D. Nicholas Mcletchie

Research output: Contribution to journalArticlepeer-review

108 Scopus citations

Abstract

The desert moss Syntrichia caninervis exhibits one of the most skewed sex ratios in the plant kingdom, with female individuals far outnumbering male individuals (exceeding 14♀:1♂). The 'cost of sex hypothesis' derives from allocational theory and predicts that the sex which is most expensive should be the rarer sex. This hypothesis, which, as considered here represents the realized cost of sexual reproduction, is contingent upon two assumptions that are explored: (1) that male sex expression is more expensive than female sex expression, and (2) that sexual reproduction is resource limited. Using inflorescence biomass and discounting sperm, male sex expression was found to be in the neighborhood of one order of magnitude more expensive than female sex expression, and this difference is reflected in higher numbers of gametangia per male inflorescence, presence of paraphyses in male inflorescences, and a much longer developmental time for male inflorescences. The realized cost of female reproduction from two communities dominated by S. caninervis was found to be lower than the realized cost of male sexual reproduction. Resource-limited reproduction was assessed by determining the frequency of sporophyte abortion, the age distribution of sporophyte abortions, and patterns of sporophyte abortion that may be density dependent. Among ten sexually reproducing populations, abortive sporophytes occurred at a frequency of 0.64. Abortive sporophytes averaged 8% the mass of mature sporophytes, and cohort sporophytes from the same individual female were found to abort in a density-dependent pattern. We conclude that the two assumptions, upon which the cost of sex hypothesis depends, are supported.

Original languageEnglish
Pages (from-to)1599-1608
Number of pages10
JournalAmerican Journal of Botany
Volume87
Issue number11
DOIs
StatePublished - Nov 2000

Keywords

  • Allocation
  • Bryophyte
  • Cost of sex
  • Cryptogamic crust
  • Desert
  • Haploid dioecy
  • Sex ratios
  • Sporophyte abortion
  • Syntrichia caninervis

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Genetics
  • Plant Science

Fingerprint

Dive into the research topics of 'The cost of realized sexual reproduction: Assessing patterns of reproductive allocation and sporophyte abortion in a desert moss'. Together they form a unique fingerprint.

Cite this