INDUCED VARIABILITY FOR C18 UNSATURATED FATTY-ACIDS IN ETHIOPIAN MUSTARD

The improvement of oil composition for C18 unsaturated fatty acids is one of the most important breeding objectives for the development of h igh-quality Ethiopian mustard oil. The objective of this research was to induce variability for fatty acid composition in this species using chemical mutagenesis. Seeds of line C-101 were treated with 1% ethylm ethane sulfonate and the progenies of 8331 M2 plants were screened for fatty acid composition of the oil with near infrared reflectance spec troscopy followed by gas liquid chromatography on selected plants. Ole ic and linoleic desaturation ratios (ODR and LDR, respectively) were u sed to detect putative mutants with altered levels of C18 unsaturated fatty acids. Seven of these mutants were isolated and M4 lines were de veloped. Six lines were characterized by low ODR, showing an increase in oleic acid and a reduction in linoleic acid. Three of these lines a lso showed reduced levels of linolenic acid. The other mutant line sho wed a decrease in both LDR and linolenic acid content. Since different enzyme systems seemed to be altered, a further oil improvement for C1 8 unsaturated fatty acids may be achieved through recombination among mutants.