FUNDING
This work was supported by the Swiss National Science Foundation [P2BEP3_175254] and USDA National Institute of Food and Agriculture gransts 2016-67013-25088 and WIS01651. Participation of coauthor KM was supported by the Utah Agricultural Experiment Station, and this is UAES publication #9516.  
 
ACKNOWLEDGEMENTS
We thank Chris Cole, Jack Schaefer, Allyson Richins, Andrew Helm and the Walnut street greenhouse staff for help with setting up the experiments, Mark Zierden for assistance with the chemical analyses, Rick Jellen for cytotype identification and Rebecca Best for advice regarding statistical analyses.