The variation in oil content, oil yield and fatty acid compositions of 103 sesame landraces was investigated. The landraces varied widely in their oil quantity and quality. The oil content varied between 41.3 and 62.7%, the average being 53.3%. The percentage content of linoleic, oleic, palmitic and stearic acids in the seed oil ranged between 40.7-49.3, 29.3-41.4, 8.0-10.3 and 2.1-4.8%, respectively. Linolenic and arachidic acids were the minor constituents of the sesame oil. Linoleic and oleic acids were the major fatty acids of sesame with average values of 45.7 and 37.2%, respectively. The total means of oleic and linoleic acids as unsaturated fatty acids of sesame were about 83% which increases the suitability of the sesame oil for human consumption. The superiority of the collection was observed in oil content. The oil content of a few accessions was above 60%, proving claims that some varieties of sesame can reach up to 63% in oil content. The accessions with the highest oil content were relatively richer in the linoleic acid content while there were some landraces in which linoleic and oleic acid contents were in a proportion of almost 1:1. The results obtained in this study provide useful background information for developing new cultivars with a high oil content and different fatty acid compositions. Several accessions could be used as parental lines in breeding programmes aiming to increase sesame oil quantity and quality.

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Sesame mutants with closed capsules, determinate growth habit and wilt resistance, have been proposed to be suitable for intensive management conditions facilitating mechanized harvesting.

The Mediterranean sesame core collection contains agro-morphologically superior sesame accessions from geographically diverse regions in four continents. In the present investigation, the genetic diversity and population structure of this collection was analyzed with 5292 high-quality SNPs discovered by double-digest restriction site associated DNA (ddRAD) sequencing, a cost-effective and flexible next-generation sequencing method. The genetic distance between pairs of accessions varied from 0.023 to 0.524. The gene diversity was higher in accessions from Asia than from America, Africa, and Europe. The highest genetic differentiation was observed between accessions collected from America and Europe. Structure analysis showed the presence of three subpopulations among the sesame accessions, and only six accessions were placed in an admixture group. Phylogenetic tree and principal coordinate analysis clustered the accessions based on their countries of origin. However, no clear division was evident among the sesame accessions with regard to their continental locations. This result was supported by an AMOVA analysis, which revealed a genetic variation among continental groups of 5.53% of the total variation. The large number of SNPs clearly indicated that the Mediterranean sesame core collection is a highly diverse genetic resource. The collection can be exploited by breeders to select appropriate accessions that will provide high genetic gain in sesame improvement programs. The high-quality SNP data generated here should also be used in genome-wide association studies to explore qualitative trait loci and SNPs related to economically and agronomically important traits in sesame.