Identification of Molecular Markers Linked to the Wilt Resistance Gene FuJ7（t） in Flax

A cross between wilt resistant flax variety Jinya7 and susceptible variety Jinyal was made for mapping wilt resistance gene(s). The inoculation test of F1 and F2 progeny proved that the resistance of Jinya7 to wilt is controlled by two dominant genes. With 48 EcoRⅠ /MseⅠ primer combinations, amplified fragment length polymorphisms (AFLP) analysis was performed on two parents and their F2 resistance and susceptibility bulks. A total of about 3 300 distinguishable bands were amplified, of which three bands had stable differences. The genetic linkage analysis of the three polymorphic DNA fragments with the resistance gene(s) was made in the F2 segregating population derived from the cross between Jinya7 and Jinyal. The DNA fragment AG/CAG was found closely linked to one of the wilt-resistant genes, which with a genetic distance of 5.2cm, was tentatively named FuJ7(t). The cloned fragment AG/CAG was sequenced and then converted successfully to a sequence characterized amplified region (SCAR) marker, which can be used more conveniently in the identification and marker-assisted selection for the wilt resistance gene FuJ7(t) to flax wilt.