Assessing Inter-Relationship of Sesame Genotypes and their Traits Using Cluster Analysis and Principal Component Analysis Methods

Abstract

The study was carried out from 2011-2013 cropping seasons in three locations of Northern Ethiopia (a total of 7 environments) and thirteen sesame genotypes were evaluated. The objective of this study was to determine the interrelationship of the genotypes and their genetic divergence. The experiment was laid out in randomized complete block design with three replications. The thirteen sesame genotypes were grouped into four clusters based on the similarity of their agronomic traits and the dendrogram showed that clusters I, II, III and IV had 9, 1, 1 and 2 number of genotypes and the highest grain yield (918.1 kg haG1) as well as highest oil content (55.1%) was observed in cluster III. The Mahalanobis’s (D2) distance, genetic divergence, among the clusters were statistically significant and the highest genetic divergence was observed between clusters II and III (D2 = 7425.5), whereas, the lowest distance was found between clusters I and III (D2 = 179.64). Eight Principal Components (PCs) were extracted from the eight agronomic traits of sesame and the first three PCs accounted for 88.49% of the total variance (45.05, 28.25 and 15.20% for PC1, PC2 and PC3, respectively) and these three PCs were considered as significant. G1 and G4 were highly associated with traits such as grain yield, oil content, length of capsule bearing zone and number of capsules and G12 and G13 were relatively better yielding genotypes. G2 that aligned with days to maturity confirms its delaying character in maturity.