The use of the principal component analysis in ranking hemp (<i>Cannabis sativa</i> L.) accessions according to the seed oil fatty acid composition for crop improvement

Abstract

The use of modern methods for assessing the genotypic diversity of breeding material is effective in crop improvement. Interpretation of the results of a study of the fatty acid biochemical composition in seeds of hemp (Cannabis sativa L.) accessions is one of important stages in breeding oilseed varieties, since hemp possesses a unique fatty acid composition (FAC) among other oilseed crops in Russia. Studies of regularities in formation of seed oil FAC and the principal component analysis (PCA) of fatty acid contents have scientific significance and practical value for ensuring the acceleration of oilseed variety breeding aimed at improving quality and biological activity of oil. The use of PCA can be an effective in achieving this goal. The fatty acid profile of oil has been evaluated at the N.I. Vavilov Institute of Plant Genetic Resources in 25 hemp accessions from the VIR hemp collection. Local and industrial hemp varieties and breeding material of the Middle Russian ecotype were grown in Penza Province with a temperate continental climate on meadow-black soils of the Middle Volga Region of Russia. The seed oil FAC was studied using gas-liquid chromatography with mass spectrometry on an Agilent 6850 chromatograph. The results were processed using the UniChrom and AMDIS software. High content of omega-3 stearidonic fatty acid was found in accessions k-205 from Ukraine (1.23%) and k-168 from Russia (0.87%); that of α-linolenic acid in k-168 from Russia (0.82%) and k-224 from GDR (0.39%); of linoleic acid in k-154 (67.29%), k-360 (66.24%), and k-150 (64.58%) (all three from Russia); of γ-linolenic acid in k-88 from Russia (2.43%) and k-211 from GDR (1.92%). It has been established that the formation of hemp seed oil FAC is a multifactorial process. The main factor determined 27.8% of the variability. The presence of both positive and negative factor loadings was revealed. The highest factor loading for the variance of a complex of characters of the oil FAC is on the main factor, i.e. linoleic acid (+0.73). In relation to this acid, negative loadings were detected for myristic acid (−0.81), lauric acid (−0.78), palmitoleic acid (−0.72), and oleic acid (−0.72). The content of bioactive omega-6 diunsaturated linoleic acid was negatively associated with the content of omega-9 monounsaturated oleic acid, as well as with the content of polyunsaturated omega-6 γ-linolenic, omega-3 stearidonic, and omega-3 α-linoleic acids. The obtained information can be used for identifying accessions with the optimal FAC for their involvement in breeding oilseed hemp varieties.