Effect of gamma-irradiation on the fatty acid composition and susceptibility to powdery mildew (Erysiphe cruciferarum) of oilseed rape plants

M. Petkova1*, M. Dimova2, D. Dimova1, S. Bistrichanov3

1Department of Genetics and Plant Breeding, Faculty of Agronomy, Agricultural University, 12 Mendeleev, 4000 Plovdiv, Bulgaria 2Department of Phytopathology, Faculty of Plant Protection and Agroecology, Agricultural University, 12 Mendeleev, 4000 Plovdiv, Bulgaria 3Department of Plant Protection, Faculty of Agronomy, University of Forestry, 10 Kliment Ohridsky, 1756 Sofia, Bulgaria

Abstract. The present study investigates the effect of induced mutagenesis for improving the quality of oil from the seeds of oilseed rape (Brassica napus) and disease resistance. Fatty acid composition of the oil obtained from seeds irradiated with gamma-rays with absorbed dose 100 Gy and 150 Gy from M1 and M2 generation was analyzed by gas chromatography. The results from biochemical analysis revealed that compared with non-irradiated plants, irradiated plants exhibit a low content of oleic acid and high content of linoleic acid and linolenic acid. There is a tendency to increase total crude fat content in M1 and M2 populations of Abacus cultivar, compared with unexposed plants. Alterations in the biochemical content after gamma rays treatment is associated with changes in sensitivity to the powdery mildew pathogen (Erysiphe cruciferarum). The findings of the gas chromatography analysis of the quantitative and qualitative composition of fatty acids in irradiated rapeseed plants makes it possible to assess the effect that change in the fatty acid content has on the resistance to powdery mildew.