Genetic Characterization of Russian Rapeseed Collection and Association Mapping of Novel Loci Affecting Glucosinolate Content.

Rapeseed is the second most common oilseed crop worldwide. While the start of rapeseed breeding in Russia dates back to the middle of the 20th century, its widespread cultivation began only recently. In contrast to the world's rapeseed genetic variation, the genetic composition of Russian rapeseed lines remained unexplored. We have addressed this question by performing genome-wide genotyping of 90 advanced rapeseed accessions provided by the All-Russian Research Institute of Oil Crops (VNIIMK). Genome-wide genetic analysis demonstrated a clear difference between Russian rapeseed varieties and the rapeseed varieties from the rest of the world, including the European ones, indicating that rapeseed breeding in Russia proceeded in its own independent direction. Hence, genetic determinants of agronomical traits might also be different in Russian rapeseed lines. To assess it, we collected the glucosinolate content data for the same 90 genotyped accessions obtained during three years and performed an association mapping of this trait. We indeed found that the loci significantly associated with glucosinolate content variation in the Russian rapeseed collection differ from those previously reported for the non-Russian rapeseed lines.

Ultra-performance liquid chromatography-mass spectrometry for precise fatty acid profiling of oilseed crops.

Oilseed crops are one of the most important sources of vegetable oils for food and industry. Nutritional and technical properties of vegetable oil are primarily determined by its fatty acid (FA) composition. The content and composition of FAs in plants are commonly determined using gas chromatography-mass spectrometry (GS-MS) or gas chromatography-flame ionization detection (GC-FID) techniques. In the present work, we applied ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) technique to FA profiling of sunflower and rapeseed seeds and compared this method with the GC-FID technique. GC-FID detected 11 FAs in sunflower and 13 FAs in rapeseed, while UPLC-MS appeared to be more sensitive, detecting about 2.5 times higher numbers of FAs in both plants. In addition to even-chain FAs, UPLC-MS was able to detect odd-chain FAs. The longest FA detected using GC-FID was an FA with 24 carbon atoms, whereas UPLC-MS could reveal the presence of longer FAs with the tails of up to 28 carbon atoms. Based on our results, we may conclude that UPLC-MS has great potential to be used for the assessment of FA profiles of oil crops.

UPLC⁻MS Triglyceride Profiling in Sunflower and Rapeseed Seeds.

Sunflower and rapeseed are among the most important sources of vegetable oil for food and industry. The main components of vegetable oil are triglycerides (TAGs) (about 97%). Ultra- performance liquid chromatography coupled with mass spectrometry (UPLC⁻MS) profiling of TAGs in sunflower and rapeseed has been performed and the TAG profiles obtained for these species have been compared. It has been identified that 34 TAGs are shared by sunflower and rapeseed. It was demonstrated that TAGs 52:2, 52:5, 52:6, 54:3; 54:4, 54:7, 56:3, 56:4, and 56:5 had the highest variability levels between sunflower and rapeseed with the higher presence in rapeseed. TAGs 50:2, 52:3, 52:4, 54:5, and 54:6 also showed high variability, but were the most abundant in sunflower. Moreover, the differences in TAG composition between the winter-type and spring-type rapeseed have been revealed, which may be associated with freezing tolerance. It was shown that winter-type rapeseed seeds contain TAGs with a lower degree of saturation, while in spring-type rapeseed highly saturated lipids are the most abundant. These findings may give new insights into the cold resistance mechanisms in plants the understanding of which is especially important in terms of global climate changes.