Water availability drives population divergence and sex‐specific responses in a dioecious plant

Abstract

PREMISE:Water availability is an important abiotic factor, resulting in differences between plant species growing in xeric and mesic habitats. Species with populations occurring in both habitat types allow examination of whether water availability has acted as a selective force at the intraspecific level. Investigating responses to water availability with a dioecious species allows determination of whether males and females, which often have different physiologies and life histories, respond differently. METHODS:An experiment varying water availability was performed under an outdoor rain-out shelter using plants from two mesic and two xeric populations of the dioecious plant Silene latifolia. Early growth rate, flowering propensity, flower size, and specific leaf area were measured. At the end of the season, the plants were harvested, aboveground and root biomass were measured, and the total number of flowers and fruit produced were counted. RESULTS:Compared to the two mesic populations, plants from the two xeric populations grew more slowly, were less likely to flower, took longer to flower, had thicker leaves, invested less in aboveground biomass and more in root biomass, produced fewer flowers and fruit, but were more likely to live. Many traits exhibited significant habitat type × treatment interactions. Compared to the xeric populations, males-but not females-from mesic populations had less root biomass and greatly reduced their flower production in response to low water availability. CONCLUSIONS: Mesic and xeric populations responded in ways congruent with water availability being a selective force for among-population divergence, especially for males.

Canopy architecture and diurnal CO2 uptake in male and female clones of yerba‐mate cultivated in monoculture and agroforestry

“…Lower SLA in yerba-mate females than in males in MO is comparable to SSD of Silene latifolia, where females from the xeric habitat had the lowest SLA (Delph, 2019). Then we can argue that lower SLA in T A B L E 2 Architectural traitsmetamer number and length (cm), leaf number and elevation ( ), and specific leaf area (SLA, mg cm À2 )-of two yerbamate genders (female, ♀ and male, ♂) and four clones ('1', '12', '82' and '84') grown in two cultivation systems (CS): agroforestry system (AFS), and monoculture (MO).…”

“…Some species increase SLA under shading (Gunn et al, 1999), but yerba‐mate grown under AFS did not change its SLA. Lower SLA in yerba‐mate females than in males in MO is comparable to SSD of Silene latifolia , where females from the xeric habitat had the lowest SLA (Delph, 2019). Then we can argue that lower SLA in yerba‐mate females from MO (Table 2) can reflect their higher sensitivity to high‐light, within canopy C and water cycles than in males.…”

Quantitative trait locus mapping reveals an independent genetic basis for joint divergence in leaf function, life‐history, and floral traits between scarlet monkeyflower (Mimulus cardinalis) populations

“…In perennial Silene latifolia Poir. [Caryophyllaceae], xeric populations tended to have thicker leaves but also slower growth trajectories compared to mesic populations, suggesting tolerance (Delph, 2019). In contrast, increased leaf succulence (same as our thickness) and early flowering were significantly associated with aridity across replicate clines of annual M. guttatus (Kooyers et al, 2015), parallel to annualized M. cardinalis .…”

Quantitative trait locus mapping reveals an independent genetic basis for joint divergence in leaf function, life-history, and floral traits between scarlet monkeyflower (Mimulus cardinalis) populations

“…for tolerance vs. escape) depending on life history. For example, in perennial Silene latifolia, populations from xeric sites tended to be have thicker leaves but also slower growth trajectories compared to mesic populations (Delph, 2019). Similarly, work with annual Arabidopsis accessions suggests that complex combinations of environments (perhaps associated with winter vs. spring annual life histories) may be as important as any single environmental axis in shaping joint variation in fast-slow and LES traits (Sartori et al, 2019).…”