Abstract Detail

Evolutionary Developmental Biology (Evo-Devo)

Spriggs, Elizabeth [1], Edwards, Erika J. [2], Donoghue, Michael [3].

Seasonal heteroblastic leaf sequences provide insight into the evolution of temperate leaf form.

The correlation between temperature and leaf margin is well established and has frequently been used to predict paleoclimates. Recently, leaf shape associations with climate have also been documented, and phylogenetic analyses have shown that these traits can evolve rapidly as lineages shift into new habitats. The adaptive significance of leaf teeth and of leaf shape, however, is not well understood, and there is substantial variation both within species and within individual plants. We show that leaf variation within individuals is highly regular in five distantly related Viburnum species and we identify consistent patterns in leaf shape and leaf margin traits along branches in the course of a single season. This pattern of heteroblasty is shared across diverse leaf morphologies, various growth architectures, and over 50Ma of evolutionary divergence. Further, we find that the trends in leaf form within individuals and across species are also evident among populations within two widespread Viburnum species complexes. Southern individuals of V. nudum and of V. dentatum are more ‘tropical’ while Northern individuals are more ‘temperate’ in both leaf shape and leaf margin characteristics. There is concordance between the traits that vary along branches and those that vary across latitudes, suggesting a shared mechanism in which prolonged dormancy and development within resting buds contributes to temperate leaf traits (the ‘bud packing hypothesis’). These results imply that changes in phenology could have cascading effects on leaf form and might facilitate major evolutionary transitions.

1 - Yale University, Ecology and Evolutionary Biology, 21 Sachem Street ESC 358C, New Haven, CT, 06511
2 - Brown University, Box G-W, 80 Waterman St, Providence, RI, 02912, USA
3 - Yale University, Department Of Ecology And Evolutionary Biology, 21 Sachem Street, PO Box 208105, New Haven, CT, 06511, USA

Keywords:
leaf shape
leaf margin
heteroblasty
Development
Viburnum.

Presentation Type: Oral Paper:Papers for Topics
Session: 42
Location: Hall B/The Shaw Conference Centre
Date: Tuesday, July 28th, 2015
Time: 11:15 AM
Number: 42005
Abstract ID:1020
Candidate for Awards:Katherine Esau Award