Phenotypic divergence analysis of Ethiopian faba bean landraces reveals substantial morpho agronomic diversity for crop improvement

Abstract Genetic divergence is important in plant breeding to select parents for crossing. A study was initiated to assess the extent of genetic divergence and group faba bean accessions based on their similarity and dissimilarity. The experiment was conducted at Mecha district in 2019 main cropping season. A 9x9 simple lattice design was used and 14 important agronomic traits were collected. Cluster analysis distinguished the 81 accessions into seven groups. The discrimination of accessions into so many discrete clusters suggested the presence of genetic diversity in the material evaluated. The maximum inter-cluster distance was detected between cluster I and cluster III (D 2 = 152.28**) followed by cluster III and cluster IV (D 2 = 130.22**). The high values of inter-cluster distances indicate divergence among the accessions and may be used in selection of genetically divergent parents for exploitation in crossing programs for better genetic recombination. The results of principal component (PC) analysis demonstrated that first four PCs explained 73.81% of the total variations among the 81 faba bean accessions. Plant height, number of pods per plant, number of branches per plant, biomass yield, grain yield and disease scores (chocolate spot, ascochyta blight and rust) were important in the first and second PC axes; as a result, they are important in discriminating the faba bean landraces. The study shows the importance of multivariate methods in assessing genetic divergence so as to identify possible parents for crossing considering traits of agronomic importance.