Abstract Detail

Phytochemical

Sharrett, Lucas [1], Steven, Janet [2].

Covariation among floral volatile emission traits and morphological traits in sexually dimorphic Silene species with differing pollination syndromes.

Olfactory signaling as a method for pollinator attraction is common in flowering plants, and pollinator-specific signaling can be an important factor in speciation. In this research, we are quantifying the volatile organic compounds (VOC) that serve as olfactory signals in three species of Silene (Caryophyllaceae). Silene latifolia and Silene dioica, are closely related and display differing pollinator syndromes despite the ability to hybridize. S. latifolia, the white campion, is commonly pollinated at night by the Noctuid moth Hadena bicruris. However, S. dioica is red-flowered and primarily pollinated diurnally by hoverflies (Rhingia campestris), bumblebees, and honeybees. Silene vulgaris, the third study species, also displays characteristics of a moth-pollinated flower but is distantly related to S. latifolia and S. dioica. We expect that pollinator syndrome will contribute significantly to differences in the timing and composition of VOC emissions among species, but the extent to which VOCs covary with other floral traits is not well known. Therefore, we are measuring floral traits to determine whether there is covariation among olfactory and morphological traits within species. Correlations among VOCs known to attract certain pollinators, along with morphological traits connected to pollinator identity, like stigma exsertion, would indicate simultaneous evolution of a suite of traits associated with a particular pollinator syndrome. The comparison of VOC composition among the study species will also provide insight into the number and identity of compounds that determine pollinator syndromes; compounds that are common between the two moth-pollinated species but divergent between the two closely related species are likely to be coevolving with other pollinator syndrome traits. We are also estimating heritability of VOC traits in each species, which will inform the potential for VOC composition to respond to selection. In addition, the three study species are dioecious or gynodioecious, and we are measuring both male (hermaphroditic in S. vulgaris) and female flowers to explore the potential for sexual dimorphism in VOC emissions. By analyzing the scent emissions in these three species of Silene, we can better understand how pollinator selection pressures have led to divergence in S. latifolia and S. dioica. Our findings will also provide insight into within-species variation in the composition, concentration, and emissions rates of VOCs as well as potential covariance between VOCs and morphological traits within pollinator syndromes.

1 - Christopher Newport University, Department of Organismal And Environmental Biology, 1 Avenue Of The Arts, Newport News, VA, 23606, United States, 5403615099
2 - Christopher Newport University, Department Of Organismal And Environmental Biology, 1 Avenue Of The Arts, Newport News, VA, 23606, United States

Keywords:
Caryophyllaceae
Silene
pollination syndrome
plant-pollinator interactions
volatile organic compounds
sexual dimorphism.

Presentation Type: Oral Paper
Session: PHYT2, Phyochemistry II
Location: /
Date: Tuesday, July 20th, 2021
Time: 2:00 PM(EDT)
Number: PHYT2007
Abstract ID:1007
Candidate for Awards:Phytochemical Best Oral Presentation Award