Seed oil content and fatty acid composition response to ethyl methanesulphonate mutagenesis in vernonia

Vernonia [Centrapalus pauciflorus (Willd.) H.Rob.] is a novel industrial oilseed crop that can be used to produce vernolic acid, a naturally epoxidised fatty acid. The study objective was to determine whether ethyl methylsulphonate (EMS) mutagenesis significantly altered seed oil content and fatty acid compositions in selected vernonia accessions. Seeds were harvested from mutant plants with and without visual chlorophyll mutations from the Vge-1 and Vge-4 vernonia accessions, subjected to seed oil content and fatty acid composition analyses and compared with untreated controls. Visual chlorophyll mutations confirmed EMS mutation in harvested plants. Ethyl methylsulphonate mutagenesis significantly reduced vernolic acid composition, and significantly increased linoleic, oleic, palmitic, stearic and arachidic acid composition in the Vge-1 accession. In Vge-4, palmitic acid composition was significantly increased. Results obtained suggested that the effect of EMS mutagenesis on fatty acid composition in vernonia could be accession-specific and influenced by mutation level. The significant but negative association between vernolic acid and other fatty acids indicates that there is potential to increase vernolic acid while at the same time reducing the contents of other fatty acids through EMS mutagenesis in vernonia. There is a need to assess EMS mutagenesis impact on seed oil over successive generations to confirm results from this study.