Korarima (Aframomum corrorima) is one of the most threatened native spices and medicinal plant species of Ethiopia. Assessing its genetic diversity is critical to assist the breeding and conservation efforts of this crop. Information on the extent of its genetic diversity and population structure is very little. Hence, the present study was initiated to analyze the extents of genetic diversity of the crop using 12 cultivated and two wild A. corrorima populations and one related species called A. zambesiacum using nine inter simple sequence repeats markers. The populations were collected from 12 administrative zones of Ethiopia. Accordingly, nine ISSR primers were selected and generated a total of 109 scorable DNA bands. A total of 104 scorable bands were found to be polymorphic and reproducible. The markers showed a high level of mean percentage of polymorphic loci (PPL) (94.73%), mean expected heterozygosity (H) (0.49), and higher polymorphic information content (PIC) (0.60). Similarly, the study samples revealed higher extents of genetic diversity as evidenced from mean Nei’s gene diversity (H) (0.36) and mean Shannon’s diversity index (I) (0.48). Two and five private loci (Ap) were observed from cultivated and wild A. corrorima populations respectively while nine private loci were detected in A. zambesiacum population. Analysis of molecular variance (AMOVA) showed 64.8% intra-population variations and 34.2% inter-population variations. The AMOVA also revealed that variation among populations was highly significant (P < 0.001) which was supported by the relatively lower extent of gene differentiation (GST = 0.41) and high gene flow (Nm = 1.62). A dendrogram based on unweighted pair-group method with arithmetic mean (UPGMA) grouped the 15 populations into six clusters revealing strong pattern of geographic origin with some cases of intermixing among members of different populations. Similarly, the populations were grouped into three sub-populations. In general, the extents of genetic diversity in A. corrorima populations of the southern and southwestern parts of Ethiopia look high. West Omo, Sheka, Gofa and Basketo populations revealed the highest genetic diversity. Thus, these zones should be used as key sites in designing conservation strategies for korarima.
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