Morphological trait evolution in Solanum (Solanaceae): evolutionary lability of key taxonomic characters

REBECCA HILGENHOF ; EDELINE GAGNON; SANDRA KNAPP ; XAVIER AUBRIOT; ERIC J. TEPE ; LYNN BOHS; LEANDRO L. GIACOMIN; YURI F. GOUVÊA; CHRISTOPHER T. MARTINE; ANDRÉS OREJUELA; CLARA INÉS OROZCO ; IRIS E. PERALTA ; TIINA SÄRKINEN

TAXON

INT ASSOC PLANT TAXONOMY

Lugar: Viena; Año: 2022

0040-0262

Solanum L. is one of the world’s largest and economically most important plant genera,including 1,245 currently accepted species and several major and minor crops (e.g.,tomato, potato, brinjal eggplant, scarlet eggplant, Gboma eggplant, lulo, and pepino).Here we provide an overview of the evolution of 25 key morphological traits for themajor and minor clades of this giant genus based on stochastic mapping using a wellsampledrecently published phylogeny of Solanum. The most evolutionarily labile traits(showing >150 transitions across the genus) relate to plant structure (growth form andsympodial unit structure), herbivore defence (glandular trichomes), pollination (corollashape and colour), and dispersal (fruit colour). Ten further traits show evolutionarylability with 50-100 transitions across the genus (e.g., specialised underground organs,trichome structure, leaf type, inflorescence position and branching, stamenheteromorphism). Our results reveal a number of highly convergent traits in Solanum,including tubers, rhizomes, simple leaves, yellow corollas, heteromorphic anthers,dioecy, and dry fruits, and some unexpected pathways of trait evolution that could beexplored in future studies. We show that informally named clades of Solanum can bemorphologically defined by trait combinations providing a tool for identification andenabling predictive phylogenetic placement of unsampled species.