Genomic location of the Fw gene for resistance to Fusarium wilt race 1 in peas.

Resistance to fusarium wilt in peas (Pisumsativum L.) caused by Fusarium oxysporum Schlect. f. sp. pisi race 1 (van Hall) Snyd. & Hans. is conferred by a single dominant gene, Fw. The gene was located in the pea genome by analyzing progenies from crosses involving genetic markers across all pea linkage groups. Phenotyping of the progenies for reaction to race 1 of the fusarium wilt pathogen was determined by field screening in a "wilt-sick" plot in Pullman, Washington. Fw was shown to be located on linkage group III, about 13 map units from Lap-1 and b and 14 map units from Td. The relatively large distances between these markers and Fw precludes the use of the linked markers in marker-assisted selection for wilt resistance. Additional markers in this region of the pea genome will be required if marker-assisted selection for Fw is to be successful.