Manuscript bioRxiv preprint doi: https://doi.org/10.1101/462663; this version postedClick April here18, 2019. to The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv aaccess/download;Manuscript;PTGR.genome.evolution.15April20 license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 1 Effects of genome size on pollen performance 2 3 4 5 How does genome size affect the evolution of pollen tube growth rate, a haploid 6 performance trait? 7 8 9 10 11 John B. Reese1,2 and Joseph H. Williams2 12 Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN 13 37996, U.S.A. 14 15 16 17 1Author for correspondence: 18 John B. Reese 19 Tel: 865 974 9371 20 Email:
[email protected] 21 1 bioRxiv preprint doi: https://doi.org/10.1101/462663; this version posted April 18, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 22 ABSTRACT 23 Premise of the Study – Male gametophytes of most seed plants deliver sperm to eggs via a 24 pollen tube. Pollen tube growth rates (PTGRs) of angiosperms are exceptionally rapid, a pattern 25 attributed to more effective haploid selection under stronger pollen competition. Paradoxically, 26 whole genome duplication (WGD) has been common in angiosperms but rare in gymnosperms.