Inheritance and mapping of a restorer gene for the rapeseed cytoplasmic male sterile line 681A

A novel cytoplasmic male sterility-fertility restoration system has been developed in rapeseed (Brassica napus). The cytoplasmic male sterile line 681A was derived from a spontaneous male sterile mutant in a newly released double-low rapeseed cultivar 'Xiangyou 13'. The restorer line 714R was identified in the interspecific progeny from a B. napus x B. juncea-cross. Genetic analysis showed that fertility restoration for 681A cytoplasmic male sterility was controlled by a single dominant nuclear gene which might originate from B. juncea. The RAPD marker S1039(-520) was found to be linked to the restorer gene in F-2 progeny of 681A x 714R with a recombination frequency of 5.45%.