Variation of seed oil content, oil yield, and fatty acids profile in Iranian Nigella sativa L. landraces

Abstract

Since there are several diverse landraces across Iran, screening the landraces with high production may lead to finding superior genotype(s) for the future conventional breeding programs. Thus, the aims of this study was to investigate the variation of oil content, yield, and profile of fatty acids in Iranian landraces of Nigella sativa L. Seed yield, oil content and oil yield significantly differed among landraces. The highest seed and oil yields were obtained from Semirom (1250 and 332 kg ha−1). Twelve different fatty acids were detected. Linoleic acid (18:2) had the highest concentration in oil of N. sativa landraces with a range of 48–55 %. After linoleic acid, oleic (18:2) and palmitic (16:0) acids, with an average of 22 and 13 %, accounted for the highest percentage of seed oil compared with the other fatty acids. Saturated fatty acids (∑SFA) was significantly different among the landraces and included 19–22 % and 21–24 % of total fatty acids. Double bond index (DBI) was significantly different among landraces and ranged between 136.5–145.3 in 2018 and 127.5–134.5 in 2019. The Gardmiran landrace had the highest Iodine value (IV) (111.7, an average of two years) and Khaf landrace had the lowest IV (105.7, in average of two years) compared with the other landraces. Cluster analysis indicated that the landraces can be divided into three groups; (1) high yield (>1000 kg ha-1 seeds and >250 kg ha−1 oil), (2) medium yield (700–1000 kg ha−1 seeds and 190–250 kg ha−1 oil), and low yield (<700 kg ha−1 seeds and <190 kg ha−1 oil) landraces. Iranian landraces were similar in fatty acid compositions and conventional breeding methods may not be a good choice to improve a special fatty acid. However, a large variations existed in seed and oil yield among the landraces for the future conventional breeding programs.