Genetic Diversity and Population Structure of Lablab (Lablab purpureus L. Sweet) Accessions from Ethiopia Using SSR Markers

Abstract

Lablab is a regionally important multipurpose legume crop used for human consumption, animal feed, and soil conservation. Despite these qualities, the potential value of this crop has not been fully utilized, and very little research attention has been given to it. The main objective of the study was molecular genetic diversity analysis of Lablab collections using 15 SSR markers. The molecular genetic diversity study of 91 Lablab collections revealed a total of 225 alleles with an average of 14.80 alleles per locus. All markers across the entire population were found to be highly polymorphic and informative with PIC values ranging from 0.78 to 0.92 with a mean value of 0.85. The average expected heterozygosity and gene diversity were 0.75 and 0.86 respectively, indicating a high level of diversity. Analysis of molecular variance showed that 94% of the total genetic variation was attributed to within populations, while only 6% was attributed to among populations. The fixation index value (0.061) recorded indicates the presence of moderate population differentiation as a result of high gene flow (Nm = 3.820) among populations. Due to high gene flow, Cluster, PCoA, and structure analysis did not exactly categorize the populations into genetic groups corresponding to their geographic origin. The observed relatively higher genetic diversity in Konso and West Wellega populations among the eight populations indicates that these areas could be considered hot-spots for genetic diversity and possible germplasm evaluation. Generally, genetic diversity obtained from this study provides inputs for Lablab conservation and improvement in Ethiopia.