Genetic Diversity and Population Structure Analysis of Vernonia [Vernonia galamensis (Cass.) Less L.] Germplasm in Ethiopia using ISSR Markers

Abstract

Vernonia galamensis L. is a wild plant from the family Asteraceae which is endemic to East Africa. This crop has the potential to become a new oil crop for industrial uses with very high content of natural epoxidized oil, which can be used for manufacturing of polyvinyl chloride, petrochemicals, cosmetic and pharmaceutical products. Knowledge of the genetic structure of the crop is important for its improvements, conservation and wise-utilization. Therefore, the present study was designed to investigate the genetic diversity and population structure of 60 V. galamensis L. germplasm in Ethiopia representing eight populations using eight inter simple sequence repeat markers. Awide range of diversity indices including number of alleles, effective number of alleles, Shannon's diversity index, percentage of polymorphic loci and polymorphic information content, were computed to determine the extents of genetic variation within and among populations. Analysis of molecular variance was performed to see genetic variation within and among the populations. All the markers used in the present study were polymorphic and highly informative. Polymorphic information content ranged from 0.5 to 0.71 with overall mean of 0.51. A high within-populations genetic diversity was confirmed with gene diversity values ranging from 0.28 to 0.43 with an overall mean of 0.36. Analysis of molecular variance revealed that most (65%) of the total genetic variation was accounted for within populations genetic variation and 35% was among population variation. Clustering and Principal co ordinate analyses did not sharply group the materials following their geographical areas of sampling. Population structure analysis revealed the presence of two sub-populations with lower degree of genetic admixture. In this study Inter simple sequence repeat markers were observed to be an appropriate molecular marker to analysis genetic diversity and population structures of Vernonia galamensis in Ethiopia. Among the studied populations, East Shoa and East Hararghe populations showed relatively higher gene diversity indicating that these sites could be targeted for breeding and conservation of Vernonia galamensis. Therefore, the present study had successfully disclosed the genetic diversity and population structure of Vernonia galamensis germplasms in Ethiopia.