Abstract Detail


Streher, Nathália Susin [1], Mayrose, Itay [2], Ashman, Tia-Lynn [3].

Is polyploidy associated with phenotypic and ecological generalization of flowers?

Polyploidy, or whole genome duplication, promotes many genotypic and phenotypic changes that have potential to shape a species’ niche, however the biotic aspect of its consequences remains poorly explored. Phenotypic changes can create barriers that reduce or cease some interactions or, instead, can eliminate barriers giving opportunity for novel interactions. For angiosperms, changes at the flower level, specifically, can impact animal-mediated pollination, a fundamental biotic interaction upon which a majority (~90%) of flowering plant species rely. These changes are thus expected to play an important role in polyploid populations as well as in the structure of their communities. Pollination determines the way a new polypoid individual successfully accesses mates of its own cytotype and overcomes its initial frequency disadvantage. Changes in floral morphology can increase the probability of a new polyploid successfully mating via two main paths. Firstly, via recruitment of new pollinators, shifting or broadening its pollination niche (i.e., changes in the composition or diversity of flower visitors, respectively). Secondly, via greater self-pollination which would reduce reliance on pollinators, narrowing its pollination niche (i.e., reducing diversity of flower visitors), relative to its diploid progenitors. Because functional floral traits are the main forces driving plant-pollinator interactions and changes in ploidy mediate a suite of floral differences (e.g., flower size and shape, scent chemistry, nectar quantity) and potentially niche breath, it is highly probable that polyploids will have different roles than diploids within communities that could cascade to effect overall network structure. For instance, if polyploids have more accessible flowers (i.e., phenotypic generalization) and, consequently, have broad pollination niches then they may interact with and connect many species. Alternatively, if polyploidy generally result in phenotypic shifts that lead to restrictive flowers (i.e., phenotypic specialization) and narrow pollination niches then they may interact with few species, being weakly connected peripherals. Thus, accessing the phenotypic accessibility of flowers to pollinators can be an indicator of the role of polyploids in communities. To test whether there is an association between floral phenotype (specialist vs. generalist) and ploidy (diploid vs. polyploid), here we assembled literature data on species floral traits and crossed these with inferred ploidy levels across a wide range of animal-pollinated species, encompassing multiple clades. We defined the phenotypic specialization or generalization status based on floral traits typically associated with filtering pollinators’ accessibility to flowers, i.e., the degree of accessibility to reward, type of reward, flower tube size, flower shape, and flower symmetry. We are also sampling pollen grains on stigmas, a direct measure of generalization, which we will show data from a single clade. In this talk, we will discuss whether there is indeed a tendency for polyploids to have more generalist floral phenotypes than diploids, its potential impacts, and future avenues to help understanding ploidy level effect on pollination.

1 - University of Pittsburgh, Department of Biological Sciences, 4249 Fifth Avenue, 215 Clapp Hall, Pittsburgh, PA, 15260, USA
2 - Tel-Aviv University, Department of Molecular Biology and Ecology of Plants, Israel
3 - Department Of Biological Sciences, 1252 Bellerock Street, Pittsburgh, PA, 15217, United States

Floral traits
herbarium specimens.

Presentation Type: Oral Paper
Number: EC07003
Abstract ID:651
Candidate for Awards:None

Copyright © 2000-2022, Botanical Society of America. All rights reserved