Abstract Detail


MacNeill, Bryan [1], McKain, Michael [2], Ruiz-Sanchez, Eduardo [3], Rodriguez Contreras, Aaron [4].

Dissecting pollinator-driven floral-trait evolution in Agave subg. Manfreda.

Agave is one of the most species-rich genera in the family Asparagaceae. The genus expanded through a radiation marked by two major diversification events: initial adaptation to arid environments and the secondary emergence of novel pollination syndromes. Agave subg. Manfreda has its center of diversity in Mexico and exhibits highly-variable floral architecture. Manfreda comprises approximately 52 species of the ~250 in Agave and is split into sections, Polianthes and Herbaceae, presenting various pollination syndromes and attracting a wide array of pollinators like bats, hummingbirds, and hawkmoths. Taxonomic descriptions of section Polianthes (and the formerly recognized genus Polianthes) have split members of this group into two series (Bravoa and Polianthes) based on character associated with hummingbird and hawkmoth pollination syndromes, respectively. Despite multiple taxonomic studies looking at morphological characters of the group, subgenus Manfreda does not have a robustly sampled molecular phylogeny to support these studies. Given the variation in pollination syndromes in the group and the absence of sufficient sampling of taxa in molecular phylogenies, the rate of pollination syndrome shifting in Manfreda is unknown. For example, Agave bulliana, Agave coetacapnia, and Agave multicolor have floral traits that align closely with hummingbird pollination syndrome: red coloration, tubular morphology, and lack of scent. Other species like Agave dolichantha, Agave virginica, or Agave neonelsonii share traits associated with hawkmoth pollination: white coloration, long trumpet-shaped tubes, and highly aromatic. To better describe the evolution of pollination syndrome in Manfreda, we reconstructed a chloroplast genome phylogeny to investigate molecular evidence of relationships among species. We sampled multiple individuals within species with varying pollination syndromes using primarily herbarium specimens. We also analyzed the floral morphospace occupancy using six different floral traits of species within this group. This analysis allowed us to categorize and visualize the different floral phenotypes within a phylogenetic framework and explore how morphology varies between and within Manfreda species. Here we present the first chloroplast genome phylogeny for the group, determining the phylogenetic relationships of species in Manfreda. These results demonstrate how pollination shifts occur within Manfreda and help to identify potential areas of future research in how interactions between pollinators and plant genomes can result in repeated origins of pollination syndromes. These results are also the first phylogeny to look in-depth at a significant and understudied clade in Agave and help develop our understanding of how the genus evolved and diversified.

1 - University Of Alabama , Department Of Biology, Science And Engineering Complex, 1325 Hackberry Ln, Tuiscaloosa, AL, 35401, United States
2 - University Of Alabama, 411 Mary Harmon Bryant Hall, Tuscaloosa, AL, 35487, United States
3 - Centro Universitario de Ciencias Biológicas y Agropecuarias, Departamento de Botánica y Zoología, Camino Ing. Ramón Padilla Sánchez 2100, Zapopan, Jalisco, 45200, México
4 - Centro Universitario de Ciencias Biológicas y Agropecuarias, Departame, Departamento de Botánica y Zoología, Zapopan, Jalisco, 45200, México

none specified

Presentation Type: Oral Paper
Number: PHYLO III007
Abstract ID:914
Candidate for Awards:None

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