Very long chain and hydroxylated fatty acids in offspring of somatic hybrids between Brassica napus and Lesquerella fendleri

Offspring of somatic hybrids between the zero-erucic acid rapeseed cv Hanna and Lesquerella fendleri were analysed regarding their fatty acid profiles . In the first back-cross generation one plant was found that produced a se ed containing up to 16.5% erucic acid and 15% eicosaenoic acid (Line 1), as well as a seed having 4.3% ricinoleic acid (Line 2). This was interpreted as due to a contribution of elongase and hydroxylase genes from the L. fend leri genome since these two fatty acids are not produced in the recipient r apeseed cultivar Hanna. Crosses between Line 1 and cv Hanna resulted in the production of seeds with 35% erucic acid (F-2) Furthermore, crosses betwee n the F-2 plants and the rapeseed cultivar Guile, producing 35% erucic acid in the seeds, resulted in F-3 seeds with 48% erucic acid. The highest amou nt of erucic acid, 61.5%, was found in the F-6 generation after crossing Li ne 1 with a high erucic acid rapeseed line, HEAR, followed by self-fertilis ation for two generations. When performing Southern-blot analysis on the F- 6 plants, seven of the nine analysed plants hybridised with the L. fendleri species-specific repetitive probe. The presence of the hydroxylase gene wa s also observed in the F-6 generation of Line 1 according to Southern-blot analysis. Hybridisation with a hydroxylase probe was seen although no hydro xy fatty acids could be detected in any of the F-6 plants. In parallel, Lin e 2 was crossed with HEAR cv Guile and self fertilised. No hydroxy fatty ac ids were detected in the F-2 generation of Line 2 and no specific hybridisa tion patterns could be found in the Southern-blot analysis.