| Title: | Do we truly understand pollination syndromes in Petunia as much as we suppose? |
| Author(s): | Rodrigues DM; Caballero-Villalobos L; Turchetto C; Assis Jacques R; Kuhlemeier C; Freitas LB; |
| Address: | "Laboratory of Molecular Evolution, Department of Genetics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil. Department of Inorganic Chemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil. Institute of Plant Sciences, Altenbergrain, Bern, Switzerland" |
| ISSN/ISBN: | 2041-2851 (Print) 2041-2851 (Electronic) |
| Abstract: | "Petunia is endemic to South America grasslands; member of this genus exhibit variation in flower colour and shape, attracting bees, hawkmoths or hummingbirds. This group of plants is thus an excellent model system for evolutionary studies of diversification associated with pollinator shifts. Our aims were to identify the legitimate pollinator of Petunia secreta, a rare and endemic species, and to assess the importance of floral traits in pollinator attraction in this Petunia species. To determine the legitimate pollinator, field observations were conducted, and all floral visitors were recorded and evaluated. We also measured the nectar volume and sugar concentration. To characterize morphological cues for pollinators, we assessed the ultraviolet (UV)-light response in detached flowers, and characterized the floral pigments and pollen volatile scents for four different Petunia species that present different pollination syndromes. Petunia secreta shares the most recent ancestor with a white hawkmoth-pollinated species, P. axillaris, but presents flavonols and anthocyanin pigments responsible for the pink corolla colour and UV-light responses that are common to bee-pollinated Petunia species. Our study showed that a solitary bee in the genus Pseudagapostemon was the most frequent pollinator of P. secreta, and these bees collect only pollen as a reward. Despite being mainly bee-pollinated, different functional groups of pollinators visit P. secreta. Nectar volume, sugar concentration per flower, morphology and components of pollen scent would appear to be attractive to several different pollinator groups. Notably, the corolla includes a narrow tube with nectar at its base that cannot be reached by Pseudagapostemon, and flowers of P. secreta appear to follow an evolutionary transition, with traits attractive to several functional groups of pollinators. Additionally, the present study shows that differences in the volatiles of pollen scent are relevant for plant mutualistic and antagonist interactions in Petunia species and that pollen scent profile plays a key role in characterizing pollination syndromes" |
| Keywords: | Anthocyanins Pseudagapostemon UV-light response chemical ecology flavonols pollinator attraction scent; |
| Notes: | "PubMed-not-MEDLINERodrigues, Daniele M Caballero-Villalobos, Lina Turchetto, Caroline Assis Jacques, Rosangela Kuhlemeier, Cris Freitas, Loreta B eng England 2018/11/06 AoB Plants. 2018 Oct 1; 10(5):ply057. doi: 10.1093/aobpla/ply057. eCollection 2018 Oct" |
