Size advantage for male function and size‐dependent sex allocation inAmbrosia artemisiifolia, a wind‐pollinated plant

Abstract

In wind‐pollinated plants, male‐biased sex allocation is often positively associated with plant size and height. However, effects of size (biomass or reproductive investment) and height were not separated in most previous studies. Here, using experimental populations of monoecious plants, Ambrosia altemisiifolia, we examined (1) how male and female reproductive investments (MRI and FRI) change with biomass and height, (2) how MRI and height affect male reproductive success (MRS) and pollen dispersal, and (3) how height affects seed production. Pollen dispersal kernel and selection gradients on MRS were estimated by 2,102 seeds using six microsatellite markers. First, MRI increased with height, but FRI did not, suggesting that sex allocation is more male‐biased with increasing plant height. On the other hand, both MRI and FRI increased with biomass but often more greatly for FRI, and consequently, sex allocation was often female‐biased with biomass. Second, MRS increased with both height and MRI, the latter having the same or larger effect on MRS. Estimated pollen dispersal kernel was fat‐tailed, with the maximum distance between mates tending to increase with MRI but not with height. Third, the number of seeds did not increase with height. Those findings showed that the male‐biased sex allocation in taller plants of A. artemisiifolia is explained by a direct effect of height on MRS.

Individual reproductive strategy of Stipa breviflora under different grazing pressures

“…In natural conditions, plant reproductive allocation is dependent on individual size (Nakahara, Fukano, Hirota, & Yahara, 2018), which is consistent with our research results. No reproductive individuals were found in the seedling stage during the field observations (Figure 3).…”

Sex‐specific selection on plant architecture through “budget” and “direct” effects in experimental populations of the wind‐pollinated herb, Mercurialis annua

“…A budget effect was found for Ambrosia artemisiifolia , but there was no direct effect of plant height (Nakahara et al. ). Our study contributes to this body of work both by examining the relationship between fitness components (pollen production and dispersal) and morphological components that tend to have been examined separately (biomass and dimensions of plant architecture), as well as by providing a novel way to estimate variance in pollen dispersal distance in a spatially explicit context.…”

The interactions between habitat, sex, biomass and leaf traits of different willow (Salix) genotypes

“…Meanwhile, focusing attention on the sex of plant specimens and the effects of the differences between the sexes may have significant ecological and practical significance. This has been demonstrated, among others, on an example of Cannabis sativa and Spinacia oleracea (Lloyd and Webb 1977), Nyssa aquatica (Shea et al 1993), Phoenix dactylifera, Silene latifolia, Zea mays and Ceratopteris richardii (Juarez and Banks 1998), Corema album (Álvarez-Cansino et al 2010), Mercurialis annua (Hesse and Pannell, 2011), Phoenix dactylifera (Intha and Chaiprasart, 2018) and Ambrosia artemisiifolia (Nakahara et al 2018), but there are few such works on willows (Mirski 2014;Yang et al 2020).…”