Genetic Diversity of Sweet Sorghum [Sorghum bicolor (L.) Moench] Accessions from Ethiopia using Simple Sequence Repeat Markers

Abstract

Sweet sorghum is a cereal crop that can grow for multiple purpose uses. Despite its global significance and potential, it faced genetic erosion, due to its low productivity and low farmers’ preferences over grain sorghum, which is not considered as one of the most important cereal crops in Ethiopia. To utilize and popularize this crop, understanding the genetic diversity and population structure is a pre-request. Therefore, this study aimed to assess the genetic diversity and population structure of 82 Ethiopian sweet sorghum accessions that represents seven geographic regions of Ethiopia using 15 simple sequence repeat markers. The study revealed a total of 116 alleles with a mean of 11.6 alleles per locus being amplified. Ten microsatellite loci were highly polymorphic with polymorphic information content (PIC) ranging from 0.75 to 0.90 and an average of 0.82. They showed high gene diversity ranged from 0.59 to 0.81 with a mean of 0.70. There was moderate genetic differentiation (FST = 0.21), showing the presence of high gene flow where 90% of the total variation was accounted for among accessions and 5% accounted for genetic variability between populations. The clustering, principal coordinate analysis (PCoA) and population structure did not cluster the studied populations into separate groups according to their geographical origin due to the presence of high gene flow (Nm = 5.033). In conclusion, from the evaluated loci the highest private alleles were observed among populations in North Wollo and Kaffa, and hence these areas can be considered hot spots for the development of improved varieties with unique traits that are well-suited to the local agricultural practices.