Format: ORAL

Violeta I. Simn-Porcar1,2, Ins Gmez-Ramos1, Marcial Escudero1, Steven D. Johnson2, Juan Arroyo1

1 Department of Plant Biology and Ecology, University of Seville, Seville, Spain 2 School of Life Sciences, University of KwaZulu-Natal, Pietermartizburg, South Africa

Linum was among the first examples of heterostyly reported by Darwin, and extensive research has been carried out since then in this study system. The yellow-flowered Linum clade (Sections Linopsis and Syllinum), mainly distributed in the Mediterranean Basin (MB) and the Cape Floristic Region (CFR) in South Africa, includes a great variation of mating phenotypes, including typical heterostyly, three-dimensional heterostyly and various types of monomorphic conditions. There is limited, mostly qualitative data about the pollination biology of the genus, but it has been suggested that pollinators may be the drivers of convergent evolution of stylar polymorphisms in the MB and CFR. In this talk, I will illustrate the use of geometric morphometrics to link the study of form and function across mating phenotypes in the yellow flaxes lineage. We use geometric morphometrics to investigate the variation of mating phenotypes in South African and Mediterranean yellow Linum species and their pollinators. Using phylogenetic analyses, we reconstruct the ancestral character and the evolution of the mating phenotypes and the convergent evolution of stylar polymorphisms in MTEs in relation with the pollination niche of species. We test the hypothesis that pollinators, through their morphological fit, are the evolutionary drivers of (i) the great variation of mating phenotypes in South African and Mediterranean yellow flaxes; and (ii) the convergent appearance of heterostyly in both separate regions. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 897890 FLAXMaTE. This work was also funded by MICINN-FEDER grant PID2021-122715NB-I00 DiversiChrom.