The inheritance of the low linolenic acid content (derivated from muta
nt lines) in rapeseed was investigated. Molecular techniques of gene m
apping through RAPD markers were applied on a microspore-derived proge
ny from a high x low linolenic acid Fl hybrid. 'Bulked segregant analy
sis' made it possible to test rapidly number of RAPD primers. Two link
age groups of 6 markers (72.7 cM and 75.6 cM) were determined. Each co
rresponded to a major QTL which explained 24% and 30.7% of the total p
henotypic variation of the linolenic acid content. It was confirmed th
at two independant mutations were implied in the low linonenic acid co
ntent.