Pollinator shifts, contingent evolution, and evolutionary constraint drive floral disparity inSalvia(Lamiaceae): Evidence from morphometrics and phylogenetic comparative methods

Kriebel, Ricardo/0000-0002-1138-7533; Drew, Bryan T./0000-0001-7248-2799; mahdjoub, mohamed malik/0000-0001-5584-6642; Celep, Ferhat/0000-0003-3280-8373WOS:000540384100001PubMed: 32484910Switches in pollinators have been argued to be key drivers of floral evolution in angiosperms. However, few studies have tested the relationship between floral shape evolution and switches in pollination in large clades. In concert with a dated phylogeny, we present a morphometric analysis of corolla, anther connective, and style shape across 44% of nearly 1000 species ofSalvia(Lamiaceae) and test four hypotheses of floral evolution. We demonstrate that floral morphospace of New World (NW)Salviais largely distinct from that of Old World (OW)Salviaand that these differences are pollinator driven; shifts in floral morphology sometimes mirror shifts in pollinators; anther connectives (key constituents of theSalviastaminal lever) and styles co-evolved from curved to linear shapes following shifts from bee to bird pollination; and morphological differences between NW and OW bee flowers are partly the legacy of constraints imposed by an earlier shift to bird pollination in the NW. The distinctive staminal lever inSalviais a morphologically diverse structure that has evolved in concert with both the corolla and style, under different pollinator pressures, and in contingent fashion.University of Wisconsin Graduate School grant; University of Wisconsin Botany Department Hofmeister Endowment; National Science Foundation-DOB grant [DOB-1046355]; National Science Foundation-DEB grant [DEB-1655606]; CONACYTConsejo Nacional de Ciencia y Tecnologia (CONACyT) [255165]; TUBITAK-BIDEB 2219 Postdoctoral Research ProgramTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK)The authors would like to thank the editors and reviewers for their time and constructive comments that improved this article. We also thank I. Cacho, E. Dariotis, and C.-L. Xiang for help obtaining floral scans in Mexico, Greece, and China, respectively, as well as the UC-Berkeley and Denver Botanical Gardens. We also thank the Phylogenetics and Evolution group in the Botany Department, University of Wisconsin, and C. Ane for statistical advice. The work was funded in part by a University of Wisconsin Graduate School grant, the University of Wisconsin Botany Department Hofmeister Endowment, a National Science Foundation-DOB grant to Sytsma (DOB-1046355), and a National Science Foundation-DEB grant to Sytsma and Drew (DEB-1655606). GG thanks financial support provided by CONACYT (project 255165). FC thanks the TUBITAK-BIDEB 2219 Postdoctoral Research Program for financial support