Variation for FAW damage in the GWAS panel
There was a wide range of variation in the damage ratings on the 289 inbred lines in the study, from a low of 2.01 to a high of 7.65 over the three years (Supplemental Table 1). The data over the three years of the study were well correlated, with correlations of 0.68 (2019 vs. 2021), 0.70 (2020 vs. 2021) and 0.72 (2019 vs. 2020). The 7-day ratings were also correlated with the 14-day ratings (0.94); (data not shown). The 31 most resistant inbred lines are highlighted in Supplemental Table 1 in green and include many lines from the USDA ARS CHPRRU (19 breeding lines and released inbred lines designated Mp); CIMMYT (10 released inbreds designated CML); and NCSU (1 inbred designated NC). Considering the large effect QTL identified in some of the CPHRRU lines in previous mapping studies (Brooks et al., 2007; Womack et al., 2018; 2020), and the strong resistance demonstrated by these lines in this study (all had average damage ratings of less than 4.0 over the three years), these lines would make excellent donor lines for introgression breeding of FAW resistance into elite but susceptible maize lines. The range of phenotypic variation was also sufficient for a successful GWAS study.