Genetic control of intermediate erucic acid content in the seed oil of the mutant Ethiopian mustard line L-935

Chemical-mutagen treatment of Ethiopian mustard (Brassica carinata A. Braun) line C-101 seeds (which contained about 441 g/kg C22:1) led to isolation of a mutant, L-935, which contained about 190 g/kg erucic acid (intermediate C22:1) in the seed oil. The objective was to determine the inheritance of the intermediate C22:1 level in this mutant. The mutant L-935 was reciprocally crossed to C-101 and to the mutant line L-2890 (which contained 112 g/kg C22:1; low). The F-1, F-2 and BC1F1 generations were obtained. Cytoplasmic effects were not observed in any of the crosses. The analysis of the fatty acid composition in the F-2 populations from the crosses of L-935 with C-101 revealed a segregation pattern fitting a ratio 1:2:1 for intermediate, high and very high C22:1 content. The segregation patterns fitted a one-locus (designated M2) model with two alleles (M-2 and m(i)) and with partial dominance of high over intermediate C22:1 content. The segregating generations of the crosses L-935 x L-2890 showed a strong transgressive segregation with C22: l values ranged from 1.3-406.5 g/kg. The analyses of the F-2, BC1F1 and F-3 generations indicated that the combination of alleles at two loci, M1 and M2 controlled the transgressive segregation for C22:1 content. The proposed genotypes (C22:1 content) for each parent were as follows: L-935 (190 g/kg C22:1)=MMm(i)m(i)EEEE; L-2890 (112 g/kg C22:1)=mmmmEEEE; and C-101 (441 g/kg C22:1)= MMMMEEEE.