Abstract Detail

Reproductive Processes

Semski, Wendy [1], Mitchell, Randall [2], Karron, Jeffrey [3].

Individual flowering schedules and floral display size in monkeyflower: a common garden study.

Flowering patterns often vary widely and can have important consequences for reproductive success. Variation among individuals in the timing of flowering onset may result in reduced flowering overlap, especially when flowering durations are short, since plants that flower early in the season are unable to mate with plants that flower later. How plants deploy their flowers over the season is also important for reproductive success. In populations where individuals deploy their flowers in pulses, with large day-to-day variation in daily floral display size, flowering may be more asynchronous so that on a given day, only a portion may be in flower. Asynchrony reduces total floral abundance, so successful outcross reproduction may decline through insufficient pollinator attraction. However, although large daily floral displays may enhance pollinator visitation and promote pollen transfer, they may also promote increased self-fertilization as pollinators transport pollen among flowers on a single plant. This type of selfing is costly because pollen that would otherwise be available for outcrossing are instead used for selfing. In populations with substantial inbreeding depression, selection should therefore favor plants that produce small floral displays over many days rather than plants that produce large displays over few days.
In nature, the relative contributions of environmental conditions and heritable traits that influence the flowering schedule are often confounded. There is a critical need for common garden studies to tease apart the environmental and genetic factors influencing flowering phenology. In this study, we raised individual plants grown from seed from 9 natural populations of Mimulus ringens in a common garden. M. ringens is a wetland perennial native to central and eastern North America, and plants produce flowers that last for only half a day. We recorded the daily floral display for the duration of the flowering period for 20 individuals from each of the 9 populations. We then analyzed the components of the flowering phenology, including date of first flower, total flower number, flowering duration, and flowering synchrony. Individual flowering schedules and components vary widely within and among populations in the common garden. First and last flowering do not fully explain the shape of the individual flowering schedules. Within populations, individuals are asynchronous in their peak flowering, which may reduce mate diversity and effective population size.

1 - UW-Milwaukee, Dept Of Bio Sci, P.O. Box 413, Milwaukee, WI, 53201, United States
2 - University Of Akron, Department Of Biology, Dept Of Biology, Akron, OH, 44325, United States
3 - University Of Wisconsin-Milwaukee, Department Of Biological Sciences, Po Box 413, Milwaukee, WI, 53201, United States

Keywords:
flowering phenology
floral display
pollination
selfing.

Presentation Type: Oral Paper
Session: RP1, Reproductive Processes 1
Location: /
Date: Thursday, July 22nd, 2021
Time: 10:15 AM(EDT)
Number: RP1002
Abstract ID:38
Candidate for Awards:None