Abstract: Using 162 families of a recombinant inbred line(RIL)population that crossed between oil-flax Longya8 and fiber-flax Alian, the fatty acid contents in the RIL population were measured by gas chromatography, and their genetic mutation and distribution traits were analyzed. Moreover, applying combined genetic model of major gene +polygene, the contents of crude fat and 5 fatty acids were primarily analyzed in genetic aspect, aiming at providing the reference for further study of RIL population. The results showed that variations of contents of fatty acid and crude fat were significant, and the transgressive segregation of fatty acid content commonly existed. The frequency distributions of crude fat and fatty acid content in RIL populations showed the characteristics of approximately normal distribution and continuous variation of quantitative traits. The analysis by major gene +polygene inheritance model revealed that the content of crude fat was controlled by three major genes with equal additive effects, and the heritability of major gene was 85%；among 5 fatty acids, the contents of linolenic acid was controlled by two major genes with duplicate effects, and the heritability of major gene was 36%；the content of linoleic acid was controlled by three major genes with equal additive effects, and the heritability of major gene was 80%；the contents of oleic acid, palmitic acid and stearic acid were controlled by polygene without major gene effects. Moreover, 11 fine RIL families with high oil and high linoleic acid content or high linolenic acid content were screened, which provides the new resources for flax quality breeding.

Key words: flax, recombinant inbred lines, fatty acid content, genetic analysis