Multigenerational Effects of Flowering and Fruiting Phenology in Plantago Lanceolata

Abstract

Abstract:Phenological patterns of flowering and fruiting can be influenced by the effects of reproductive time on seed production. We propose here that these patterns are also influenced by phenological effects on offspring quality. Furthermore, we hypothesize that there are cross-generational trade-offs between parental and offspring components of parental fitness influencing the evolution of reproductive phenology.To test our hypothesis, we examined the multigenerational effects of flowering and fruiting phenology in Plantago lanceolata. Offspring of 30 families were transplanted into field plots to measure the effects of onsets of flowering and fruiting, duration of fruiting, percentage fungal infection, and damage by grasshoppers on total seed production, our measure of the within-generational component of parental fitness. To gather information about cross-generational contributions to parental fitness, we assessed the quality of off-spring produced at different times in terms of seed mass and germination.Families significantly differed in flowering and fruiting onsets. Larger plants began flowering earlier, and earlier flowering plants matured fruits earlier and produced fruits for a longer time. Significant family-mean correlations among these traits suggest that selection on any one trait will change all three traits. A negative family-mean correlation between fruiting onset and seed production suggests that we can expect an antagonistic trade-off in response to selection on these two traits. Early fruiting significantly reduced seed predation by grasshoppers and increased seed production. In contrast, late-maturing seeds were significantly heavier and germinated more rapidly than did early-maturing seeds produced by the same plants. The directions of the multigenerational effects support the hypothesis that there are cross-generational trade-offs between parental and offspring components of parental fitness. The experiments indicate that multigenerational fitness effects should be considered in future studies addressing the evolution of flowering and fruiting phenology.

Intraspecific functional differentiation suggests local adaptation to long‐term climate change in a calcareous grassland

“…Individuals that allocated more to reproduction (high PC1 scores) had less total biomass, higher chlorophyll content, longer scapes and a later flowering phenology, consistent with a drought avoidance strategy. Similar to Lacey et al (2003), we found differences in flowering phenology associated with competitive and avoidance strategies that could increase the potential for within-population assortative mating and thus contribute to the maintenance of functional diversity within populations of P. lanceolata. The second axis of functional variation explained an equivalent amount of trait variation in P. lanceolata and reflected leaf-level trade-offs associated with resource acquisition (high SLA, leaf nitrogen, A max ) and resource conservation (LDMC, leaf C:N) (Grime 1977;Reich et al 2003;Díaz et al 2004).…”

Time after time: flowering phenology and biotic interactions

“…Most field surveys compare temporal variation in the intensity of seed and flower predation and flowering phenology to infer the direction of selection acting on phenology. Most studies found that flowering off-peak (either early [23,[34][35][36][37], or late [11,[38][39][40][41]) is associated with reduced seed predation, probably because fewer herbivores are present at those times. Similar effects are highlighted by studies indicating highest seed predation during peak flowering [42][43][44], especially when peak flowering attracts more seed predators owing to a higher density of flowers and fruits ( [28], J.A.…”

Response to joint selection on germination and flowering phenology depends on the direction of selection

“…For example, in Arabidopsis thaliana , the FLOWERING LOCUS C (FLC) gene regulates flowering time and mediates germination time by affecting seed dormancy through a pleiotropic genetic correlation (Chiang et al., 2009). Simultaneously, in A. thaliana and many flowering plants, the sequential nature of expression of phenological traits results in functional linkage, as the timing of flowering affects traits later in development such as fruit maturation and seed dispersal (Donohue, 2009; Galloway & Burgess, 2009; Lacey & Pace, 1983; Lacey, Roach, Herr, Kincaid, & Perrott, 2003). These correlations may extend into the next generation such that timing of flowering influences offspring germination environment by determining the timing of seed dispersal.…”