title: Sex change in the subdioecious shrubEurya japonica(Pentaphylacaceae).
abstract: Sex change affects the sex ratios of plant populations and may play an essential role in the evolutionary shift of sexual systems. Sex change can be a strategy for increasing fitness over the lifetime of a plant, and plant size, environmental factors, and growth rate may affect sex change. We described frequent, repeated sex changes following various patterns in a subdioeciousEurya japonicapopulation over five successive years. Of the individuals, 27.5% changed their sex at least once, and these changes were unidirectional or bidirectional. The sex ratio (females/males/all hermaphrodite types) did not fluctuate over the 5 years. In our study plots, although the current sex ratio among the sexes appears to be stable, the change in sex ratio may be slowly progressing toward increasing females and decreasing males. Sex was more likely to change with higher growth rates and more exposure to light throughout the year. Among individuals that changed sex, those that were less exposed to light in the leafy season and had less diameter growth tended to shift from hermaphrodite to a single sex. Therefore, sex change inE.japonicaseemed to be explained by a response to the internal physiological condition of an individual mediated by intrinsic and abiotic environmental factors.
authors.affiliation: School of Life Science Shandong University Jinan China; Laboratory of Forest Ecology and Physiology Graduate School of Bioagricultural Sciences Nagoya University Nagoya Japan.
authors.forename: Hui
authors.identifier: 0000-0003-2197-7075
authors.initials: H
authors.lastname: Wang
authors.affiliation: Forest Tree Breeding Center Forestry and Forest Products Research Institute Hitachi Japan.
authors.forename: Michinari
authors.initials: M
authors.lastname: Matsushita
authors.affiliation: Laboratory of Forest Ecology and Physiology Graduate School of Bioagricultural Sciences Nagoya University Nagoya Japan.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Tomaru
authors.affiliation: Laboratory of Forest Ecology and Physiology Graduate School of Bioagricultural Sciences Nagoya University Nagoya Japan.
authors.forename: Michiko
authors.initials: M
authors.lastname: Nakagawa
keywords: internal physiological condition; sex expression; sex ratio; steady state; subdioecy