Figure 3. Multiplex polymerase chain reaction (PCR) amplification patterns of Xrems1303 + Xgwm18 in 46 wheat cultivars, accessions, and breeding lines. The black or white arrows indicate the diagnostic band of specific markers. The lane codes are corresponding to that of cultivars or lines shown in Table 4. Resistant genotypes are shown based on the infestation results of biotype 2 Russian wheat aphid (RWA): RR = homozygous resistant, Rr = heterozygous resistant, rr = homozygous susceptible. The size difference among Xgwm18 bands reflects polymorphism among the wheat cultivars or recurrent parents of backcross-derived breeding lines.