Genetic diversity study of Ethiopian hot pepper cultivars (Capsicum spp.) using Inter Simple Sequence Repeat (ISSR) marker

Hot pepper (Capsicum spp.) is an economically important spice widely cultivated and consumed in Ethiopia. In spite of its wide importance, there is no information available on the molecular genetic diversity of this crop. Cultivars characterization is an important link between the conservation and utilization of plant genetic resources in various breeding programs. Using five ISSR primers, a total of 37 scorable bands were generated of which 35 (94.6%) were polymorphic bands. The diversity of polymorphic bands within population ranged from 51.35% to 91.89 % with a mean of 66.6 %, Nei’s genetic diversity of 0.19 - 0.30 with a mean of 0.28, and Shannon information index of 0.29 - 0.45 with a mean of 0.43. With all diversity parameters, the highest diversity was obtained from amhara2 populations, whilst the lowest was from Oromia2. From Jaccard’s pairwise similarity coefficient, Oromia1 and oromia2 were the most related populations exhibiting 0.956 similarity and Semn omo and Amhara 2 were the most distantly related populations with similarity of 0.827. Clustering was showed that there is strong correlation between geographic distance and genetic diversity of Ethiopian hot peppers cultivars because geographically closely related species have been clustered together. Amhara 2 populations exhibited the highest genetic diversity so that the populations should be considered as the primary sites in designing conservation areas for this crop in Ethiopia.  Further, it is suggested that molecular markers are valid tags for the assessment of genetic diversity in Capsicum spp. cultivars.