Molecular markers linked to the Aegilops variabilis‐derived root‐knot nematode resistance gene Rkn‐mn1 in wheat

Aegilops variabilis no. 1 is the only known source of resistance to the root‐knot nematode Meloidogyne naasi in wheat. Previous studies showed that a dominant gene, Rkn‐mn1, was transferred to a wheat translocation line from the donor Ae. variabilis. Random amplified polymorphic DNA (RAPD) analysis was performed on the wheat cultivar ‘Lutin’, on Ae. variabilis, on a resistant disomic addition line and on a resistant translocation line. For genetic and molecular studies, 114‐117 BC3F2 plants and F3‐derived families were tested. Five DNA and one isozyme marker were linked to Rkn‐mn1. Three RAPD markers flanking the Rkn‐mn1 locus were mapped at 0 cM (OpY16‐1065), 0.8 cM (OpB12‐1320) and 1.7 cM (OpN20‐1235), respectively. Since the Rkn‐mn1 gene remained effective, its introduction into different wheat cultivars by marker‐assisted selection is suggested.