Abstract Detail

Ecology

Lozada Gobilard, Sissi [1], Fedorenka, Aliza [2], Klein, Tamir [3], Lenhard, MIchael [4], Sapir, Yuval [5].

Conflicting selection on floral size and its relation with heat reward in Royal Irises.

Floral traits evolve in response to pollinators causing a strong selection on floral characteristics, in particular flower size. Larger flowers are more attractive to pollinators because they are easier to detect from a distance and can be a visual signal of higher energetic and nutritive rewards, mostly nectar but also resin or heat. Therefore, a positive correlation between floral advertisement and floral reward is expected. This positive relation is known as honest signaling. However, large flowers can be very costly to produce, and smaller flowers may be favored under certain environmental conditions. In particular, drought and other abiotic stress tends to select for smaller flowers. Thus, in arid environments the selection by pollinators and abiotic factors is likely conflicting. In the Royal Irises, large flowers offer heat reward to male bees that use flowers as night-shelters. The observed large flowers of the Royal Irises suggest that, despite a possible cost in water loss, which may exerts negative directional selection that favors smaller flowers, pollinator-mediated selection favors large flowers because size honestly signals for heat reward. In this study we aim to test this hypothesis using two extreme populations with large and small flowers of a Royal Iris species Iris atropurpurea.

1 - Tel Aviv University, Botanical Garden, Tel Aviv University, Tel Aviv, TA, 69978, Israel
2 - Weizmann Institute, Department of Plant and Environmental Science
3 - Weizmann Institute Of Science, 234 Herzl, 234 Herzl, Rehovot, M, 76100, Israel
4 - University of Potsdam, Institute for Biochemistry and Biology AG Genetics, Karl-Liebknecht-Str. 24-25, Potsdam, 14476 , Germany
5 - Tel Aviv University Botanical Garden, Tel Aviv University, Ramat Aviv, Tel Aviv University, Ramat Aviv, Tel Aviv, TA, 69978, Israel

Keywords:
Selection
flower size
heat reward
pollination
floral traits
plant-pollinator interactions.

Presentation Type: Oral Paper
Session: ECO5, Ecology: Stress
Location: /
Date: Thursday, July 22nd, 2021
Time: 1:30 PM(EDT)
Number: ECO5005
Abstract ID:1126
Candidate for Awards:Ecological Section Best Graduate Student Paper