Molecular Genetic Diversity of Plectranthus edulis (Vatke) Agnew as Revealed by Inter Simple Sequence Repeat Markers

Plectranthus edulis (Vatke) Agnew is an underutilized and neglected ancient Ethiopian indigenous annual tuber crop. Very limited research has been done to improve this crop especially in the area of molecular genetic diversity. Therefore, this study was aimed to assess the genetic diversity of this crop using ISSR markers. Fourteen ISSR primers were screened, and four polymorphic and reproducible primers were selected. These primers generated a total of 46 scorable bands of which 42 were polymorphic. Primer UBC-880 showed 100% polymorphism, and a unique band in some individuals was observed. Within-population diversity ranged from 41.30% to 65.22% with overall percentage of polymorphic loci of 91.30%, Nei’s gene diversity of 0.18–0.30 with overall diversity of 0.33, Shannon information index of 0.25–0.39 with overall index of 0.48, and 74.23% within-population variation was detected. Sodo Zuria, Gojam-II and Areka populations showed the highest diversity, whereas the lowest was exhibited by Nekemte. According to Jaccard’s pairwise similarity coefficient, Ambo and Sodo Zuria were most related populations exhibiting 0.648 similarity coefficient, and Gojam-I and Sodo Zuria were the most distantly related populations with similarity coefficient of 0.489. Wolaita and Wollega populations showed the highest genetic diversity so that these populations should be considered as the primary sites in designing conservation strategies for this crop.