The QTLs for KNPS were identified using MapQTL 6.0 (based on CIM, https://www.kyazma.nl/index.php/mc.MapQTL/), IciMapping 4.1 (based on ICIM, http://www.isbreeding.net/software/?type=detail&id=18), and QTLNetwork 2.0 (based on MLMA, http://ibi.zju.edu.cn/software/qtlnetwork/). For MapQTL 6.0 and IciMapping 4.1, the average KNPS values of each KJ-RIL in each environment were used for individual environment QTL mapping analysis. For QTLNetwork 2.0, the KNPS values of each KJ-RIL in each replication of the 10 environments were assembled to perform combined QTL analysis across environments to identify QTLs with additive-by-environment (A by E) interaction effects. The overlapping confidence intervals detected with the abovementioned programs were used to predict the candidate genes based on the sequence information of the flanking markers and the IWGSC WGA v0.4 assembly of chromosome 4A (https://urgi.versailles.inra.fr/download/iwgsc/IWGSC-WGA_Sequences/).