Variation and genetic analysis of fatty acid composition in flax (Linum usitatissimum L.)

Flax (Linum usitatissimum L.) is an important source of oil rich in omega-3 fatty acids (especially alpha-linolenic acid accounting for > 50%), which is proven to have health benefits and utilized as an industrial raw material. alpha-Linolenic acid is a polyunsaturated fatty acid that readily undergoes oxidative transformation. Autoxidation of alpha-linolenic acid is the principal process contributing to the development of off-flavors, loss of color, and alteration in the nutritional value of linseed oil. However, there is huge a demand on the market for oils having different compositions of fatty acids, including the linseed oil characterized by improved stability. For this purpose, a complete diallel cross was performed in this study using six flax genotypes varying in the fatty acid content to estimate the genetic parameters. The analysis of variances carried out for the studied traits (content of oleic, linoleic and alpha-linolenic acid) indicated large differences among the genotypes. Variances due to GCA were much higher in magnitude than those related to SCA for the content of linoleic and alpha-linolenic acid, which indicated the superiority of additive gene effects in determining the inheritance of these traits. The nonadditive gene action played an important role for oleic acid content, since the magnitude of SCA effect was almost two times higher than GCA effect. The parental lines of linola (Linola KLA and Linola KLB) exhibited the highest concentration of favorable alleles for the two traits (high content of linoleic acid and low content of alpha-linolenic acid) and were thus found suitable for a continuous improvement program. On the basis of the SCA effect, five cross combinations, were found to be promising F1 hybrids for use as a source population for further selection, in order to achieve fatty acid changes in linseed. These combinations allow selecting varieties with 1:1 and 2:1 ratio of omega-6:omega-3 fatty acids for producing oil with an extended shelf life for food products.

Automated summary

Flax is an important oil source rich in omega-3 fatty acids, but its oil is prone to oxidation. This study conducted a complete diallel cross using six flax genotypes and estimated the genetic parameters. Promising hybrids were identified for producing oil with an extended shelf life.