Morphological Characterization and Genetic Diversity of Sesame (Sesamum indicum L.) Varieties Cultivated in Ethiopia

The experiments were conducted to identify and group sesame genotypes by morphological and genetic characteristics.

Ten nationally released sesame genotypes were obtained from Humera and Melka-Worer research centers and planted at Humera experimental sites. The number of primary branches per plant was found higher (5.93) for M-80. However, the number of nodes per plant was grouped as ‘more’ (24.13) for M-80 compared to Humera-1, which was grouped as the ‘highest’ (26.13). Plant height was tall in all the sesame genotypes studied. Likewise, the number of nodes per plant in all the genotypes was grouped as more nodes per plant i.e. greater than 15. The leaf length ranged from 7.769 cm to 6.67 cm and genotypes, Argene and K-74 had the lowest and the highest values, respectively. The variation was least in qualitative characteristics like flower colour, number of locules per pod, pod pubescence, and type of pod beak. Thousand seed weight and seed yield per kg per ha had a significance level at P=0.05. Pod length was found to be varied among the genotypes and grouped as ‘long “with a mean pod length of 2.44 cm. Hence, genotypes having a long pod length might be preferred for seed production.

The genetic characters of the genotypes were characterized and the level of polymorphism for the selected primers ranged from 56.25% to 100%. ISSR-880 was found with the least level of polymorphism while the other three (ISSR-811, ISSR-812 and ISSR-860,) were found with a high level of polymorphism. Five sesame genotypes (ADI, Humera1, Serkamo, M-80 and E) were clustered and grouped together, while three genotypes, namely, Argena, K-74, and S-Breeder appeared to have their own cluster separately.

Our study indicates that agro-morphological and genetic characterization of genotypes is useful and effective in determining polymorphisms in the sesame genotypes molecular genotyping, reproducible and it can also produce enough polymorphism to cluster and identify the genotypes.

The findings presented in this paper may prove useful in the future to include more ISSR markers and induvial genotype investigation for detailed characterization of sesame germplasm that would be important for future breeding and sesame improvement program.