*4.4. Statistics*

The data were plotted and the figures were designed using Graphpad Prism software (San Diego, CA, USA). The statistical tests were performed using either Graphpad Prism (San Diego, CA, USA) or R software and the "LSmeans and "multmultcompView" packages. Potato tolerance data were analyzed through a generalized linear modeling (GLM) approach. A negative binomial error structure was used for the GLM. The other data were analyzed with either a Students *t*-test, 1-way or 2-way ANOVA. If necessary, data was log transformed to meet ANOVA prerequisites. Tukey's honestly significant difference (HSD) tests were used to correct for multiple comparisons.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2223-7747/9/8/1022/s1, Table S1: RT-qPCR primers used in this study.

**Author Contributions:** Conceptualization, S.H., R.S. and L.A.C.J.V.; methodology and experiments, S.H., N.v.D., D.M.H.J.R., R.A.M.W.-E. and J.K.; manuscript preparation, S.H., R.S. and L.A.C.J.V.; funding acquisition, S.H., R.S. and L.A.C.J.V. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by grants from the Netherlands Organization for Scientific Research (831.15.001 to S.H., 824.14.007 to L.A.C.J.V. and BB.00534.1 to R.S.).

**Acknowledgments:** We thank Mariëlle Muskens of Agrico Research B.V. and Jan De Haas and Robert Graveland of HZPC Research B.V. for valuable feedback and providing tubers of the potato cultivars used in this study (in kind donations). In addition, we kindly acknowledge Eric Visser & Ivo Rieu (both Radboud University Nijmegen, NL) for providing the seeds of *S. dulcamara* and *S. pennellii*, respectively. Finally, we thank Emilie Reinen, Sarah Courbier and Ankie Ammerlaan of Utrecht University for technical assistance.

**Conflicts of Interest:** The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

### **References**


© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
