Genetic Diversity and Population Structure of Roselle (H. sabdariffa L.) Germplasm from Africa and Maintained at Wondogenet, Ethiopia Using a Simple Sequence Repeat (SSR) Marker

Roselle (H. sabdariffa L.) is an economically important nutritional, medicinal, and industrial plant that belongs to the Malvaceae family and is native to Africa. In Ethiopia Roselle (H. sabdariffa L.) germplasm was introduced from different parts of Africa and maintained for breeding purposes in the Wondogenet agricultural research center, but there was no information on genetic diversity by using molecular markers. Thus, assessment of the genetic diversity of available accessions is a prerequisite for genetic improvement. Therefore, the present study was aimed at assessing the extent of genetic diversity and population structure in Roselle (H. sabdariffa L.) accessions maintained in Ethiopia. A sample of 75 accessions was obtained from the, Wondogenet Agricultural Research Center. A total of 12 simple sequence repeat (SSR) markers produced 55 alleles in the range of 3 to 6, with an average of 4.58 per locus. Overall genetic diversity parameters such as the number of effective alleles (Ne), polymorphic information content (PIC), observed heterozygosity (Ho), expected heterozygosity (He), Shannon’s index (I), fixation index (F), and gene flow (Nm) were estimated to be 0.24, 0.72, 0.07, 0.5, 0.86, and 1.19, respectively. Analysis of molecular variance showed highly significant (P<0.001) molecular variances. The highest (88%) of the variation was attributed to genetic variability among individuals within populations, while 12% of the variation was observed among populations. The principal coordinate analysis (PCoA) analysis in the two-dimensional plot showed that accessions from different country collections were often grouped. The dendrogram derived from UPGMA analysis of the 12 SSR data with 75 accessions showed two major distinct clusters. In all clustering analyses, most of the accessions clustered together without considering their respective geographic origins. Generally, the present study showed the existence of wide genetic variation among Roselle accession germplasm maintained in Ethiopia. Thus, the information generated serves as baseline information for available germplasm conservation and genetic improvement.