“…At present, more than 100 powdery mildew-resistance genes or alleles mapping to 63 different loci ( Pm1 – Pm68 , Pm18 / Pm1c , Pm22 / Pm1e , Pm23 / Pm4c , Pm31 / Pm21 , Pm48 / Pm46 , and Pm17 / Pm8 ) have been reported, with the loci Pm1 , Pm3 , Pm4 , Pm5 , and Pm24 having 5, 17, 8, 5, and 2 alleles, respectively ( Li et al, 2020 ; McIntosh et al, 2020 ; He et al, 2021 ; Zhang et al, 2021 ; Wu et al, 2022 ). These include five resistance alleles, Pm4a – Pm4e , reported at the locus Pm4 , located on the long arm of chromosome 2A.…”