bioRxiv preprint doi: https://doi.org/10.1101/362400; this version posted January 8, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. 1 Life history evolution and phenotypic plasticity in parasitic eyebrights (Euphrasia, 2 Orobanchaceae) 3 Alex D. Twyford1,2, Natacha Frachon3, Edgar L. Y. Wong4, Chris Metherell5, Max R. Brown1 4 1University of Edinburgh, Institute of Evolutionary Biology, Charlotte Auerbach Road, Edinburgh, 5 EH9 3FL, UK. 6 3Royal Botanic Garden Edinburgh, 20A Inverleith Row, Edinburgh, EH3 5LR, UK. 7 4Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK. 8 5Botanical Society of Britain and Ireland, 57 Walton Rd, Bristol BS11 9TA. 9 2Author for correspondence (email:
[email protected]) 10 Manuscript received _______; revision accepted _______. 11 Running head: Life history of parasitic eyebrights 1 bioRxiv preprint doi: https://doi.org/10.1101/362400; this version posted January 8, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. 12 ABSTRACT 13 Premise of the study: Parasite lifetime reproductive success is determined by both genetic variation 14 and phenotypically plastic life history traits that respond to host quality and external environment. 15 Here, we use the generalist parasitic plant genus Euphrasia to investigate life history trait variation, in 16 particular whether there is a trade-off between growth and reproduction, and how life history traits are 17 affected by host quality.