Male flowers in Tulipa pumila Moench (Liliaceae) potentially originate from gender diphasy

Abstract

We found functionally male individuals in an otherwise hermaphroditic population of Tulipa pumila (Liliaceae) located in Tuscany (central Italy). We investigated the sex ratio of this population, followed by morphometric analyses of the scape, leaves and flowers, and tests on pollen germinability and seed number and mass, in order to infer which sexual strategy produced the observed co‐occurrence of male and hermaphrodite individuals. We found that sex ratio deviated from 1:1, and functionally male individuals showed a smaller plant size and a reduced pollen fitness (germinability and siring ability) compared to hermaphrodites. These findings point to a resource‐dependent sexual allocation strategy, probably associated with gender diphasy.

Andromonoecy in Solanum lycocarpum A. St. ‐Hil. (Solanaceae): Floral attributes, visitors and variation in sexual expression over time

“…In individuals with both sexual functions, there is a continuous variation in female function and there are no plants with only hermaphroditic flowers in the populations. In Tulipa pumila (Liliaceae), the presence of male individuals may be the result of limited resources for reproduction, indicating that the only production of staminate flowers may be a stage in growth to control sexual expression (Astuti, Pratesi, Carta, & Peruzzi, 2020). In S. lycocarpum this can also occur, but further analysis is needed at this point.…”

Two closely relatedTulipaspecies with different ploidy levels show distinct germination rates

“…This genus includes several species inhabiting open habitats, among which the only ones native to western Europe, namely Tulipa pumila Moench and Tulipa sylvestris L.; the latter presumably originated from the former via autopolyploidy (Cesca, 1986). This species reproduces sexually, and populations with functionally male flowers have been reported (Peruzzi, 2012), sharing this feature with the diploid ancestor T. pumila (Astuti et al, 2020).…”

Size-dependent sex allocation and the expression of andromonoecy in a protogynous perennial herb: both size and timing matter

“…Although gender diphasy in perennial plants most commonly involves a shift in gender expression from male to female, many species share the strategy displayed by P. alpina of shifting between male- and hermaphrodite-phases (Freeman et al 1980; Schlessman 1988), e.g., Lilium apertum (Zhang et al 2014), Lloydia oxycarpa (Niu et al 2017), Panax trifolium (Schlessman 1991), and Tulipa pumila (Astuti et al 2020). In these species, male-phase individuals are usually small and produce only one or few flowers, and it is generally thought that the small individuals in the male-phase likely contribute little to their lifetime fitness (Charlesworth 1984; Zhang and Jiang 2002).…”

“…In these species, male-phase individuals are usually small and produce only one or few flowers, and it is generally thought that the small individuals in the male-phase likely contribute little to their lifetime fitness (Charlesworth 1984; Zhang and Jiang 2002). Indeed, studies on gender diphasic species have typically failed to show any advantages in male RS of male-phase over hermaphrodite-phase individuals in terms of pollen production, flower size, pollinator visitation rate, or pollen siring ability (Peruzzi et al 2012; Zhang et al 2014; Niu et al 2017; Astuti et al 2020). However, in most of these cases, the male flowers are smaller and produce less pollen compared to hermaphroditic flowers (Zhang et al 2014; Niu et al 2017; Astuti et al 2020).…”

“…However, in most of these cases, the male flowers are smaller and produce less pollen compared to hermaphroditic flowers (Zhang et al 2014;Niu et al 2017;Astuti et al 2020).…”