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.
