Sex change in the subdioecious shrub Eurya 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 subdioecious Eurya japonica population 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 in E. japonica seemed to be explained by a response to the internal physiological condition of an individual mediated by intrinsic and abiotic environmental factors.

Sexual and temporal variations in floral scent in the subdioecious shrub Eurya japonica Thunb

“…Eurya japonica Thunb., an evergreen broadleaf understory tree belonging to the Pentaphylaceae family (approximately 0.5–3 m in height) (Tsuji & Sota, ; Wang, Matsushita, Tomaru, & Nakagawa, ), was investigated in this study. As a subdioecious species, E. japonica consists of three sexual morphs: males with staminate flowers, females with pistillate flowers, and hermaphrodites with perfect flowers (i.e., flowers with both stamens and pistils) as well as staminate flowers and/or pistillate flowers (Motooka et al., ; Tsuji & Sota, ; Wang, Matsushita, Tomaru, & Nakagawa, , ; Wang et al., ). In Japan, flowers bloom from late February to early April, lasting for about 2 weeks (Kitamoto, Takasu, & Yagi, ; Wang et al., ).…”

Repetitive sex change in the stony coral Herpolitha limax across a wide geographic range

“…The higher overall energetic state of the corals in Okinawa is evident also in their higher percentages of reproduction and sex change (both being energetically costly functions) in comparison with their GoE/A conspecifics (Table 1). Similar to the Eurya japonica shrub, which changed sex more frequently with higher growth rates and more exposure to light throughout the year 19 , the higher percentages of reproduction and sex change documented in the H. limax population in Okinawa are correlated with higher growth rates (i.e. in comparison with the Eilat and Aqaba populations) (Tables 1, 2).…”

“…the occurrence of sex change from female to male and from male to female in the same population), or even repetitively (reviewed by 7 ). This phenomenon described both in animals 6–15 and plants 6,16–19 presumably conveys a selective advantage to an individual by increasing its reproductive potential.…”

Sex‐specific scaling of leaf phosphorus vs. nitrogen under unequal reproductive requirements in Eurya japonica, a dioecious plant

“…Eurya japonica is a short‐stature (<8 m) species that typically colonizes shaded habitats in forest understory (Wang et al, 2017). No apparent habitat separation between sexes has been observed in this species (Suzuki, 2005).…”