Genetic diversity and population structure of Ethiopian faba bean (Vicia faba L.) germplasm revealed by ISSR markers

Abstract

Molecular characterization of faba bean accessions is important for future collection, conservation, and crop improvement programs. However, molecular genetic diversity of the Ethiopian faba bean accessions has not been comprehensively characterized. The present study was conducted to determine the genetic diversity and population structure of 90 faba bean landraces and six released varieties using nine inter-simple sequence repeat (ISSR) markers. The polymorphic information content (PIC), marker index (MI), resolving power (RP) and effective multiplex ratio (EMR) showed average values of 0.32, 5.87, 7.14, and 18.34 per primer, indicating high polymorphism values. The marker revealed average gene diversity of 0.26, ranging from 0.15 to 0.36. The degree of polymorphism among the landrace accessions ranged from 44.91% for the Sidama population to 72.46% for the East Hararghe population, with a mean of 57.27%. Analysis of molecular variance (AMOVA) indicated 99 % variation within and 1% variation among population, respectively. The present study revealed little to moderate population differentiation accompanied by high gene flow. Both distance-based and model-based cluster analysis distinguished seven distinct groups illustrating the conformity of results obtained from the study. Accessions from different administrative zones (AZs) of the country were distributed over most of the clusters; exhibiting high genetic diversity in collection sites. Therefore, further collection, conservation, and utilization programs would be recommended from AZs with high genetic diversity.