bioRxiv preprint doi: https://doi.org/10.1101/751982; this version posted September 4, 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 The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.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. Resistance and Tolerance to Root Herbivory in Maize were Mediated by Domestication, Spread, and Breeding Ana A. Fontes-Puebla1,2, Julio S. Bernal1* 1Texas A&M University, Department of Entomology, College Station, TX, USA. 2Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias (INIFAP)-CECH-CIRNO, Hermosillo-Sonora, México. * Correspondence: Julio S. Bernal
[email protected] Abstract Plants may defend against herbivory and disease through various means. Plant defensive strategies against herbivores include resistance and tolerance, which may have metabolic costs that affect plant growth and reproduction. Thus, expression of these strategies may be mediated by a variety of factors, such as resource availability, herbivory pressure, and plant genetic variation, among others. Additionally, artificial selection by farmers and systematic breeding by scientists may mediate the expression of resistance and tolerance in crop plants. In this study, we tested whether maize defense against Western corn rootworm (WCR) was mediated by the crop´s domestication, spread, and modern breeding. We expected to find a trend of decreasing resistance to WCR with maize domestication, spread, and breeding, and a trend of increasing tolerance with decreasing resistance. To test our expectations, we compared resistance and tolerance among four Zea plants spanning those processes: Balsas teosinte, Mexican landrace maize, US landrace maize, and US inbred maize.