Genetic diversity analysis of sorghum (Sorghum bicolor L. Moench) mutant lines by using ISSR markers

The study evaluated the genetic diversity among 20 Sorghum bicolor genotypes, including 17 mutants and 3 wild types, using Inter Simple Sequence Repeat (ISSR) markers. Nine ISSR primers were used for PCR amplification, resulting in 1248 amplicons, of which 668 (53.5%) were polymorphic, with an average polymorphism rate of 72.74%. The number of alleles per primer ranged from 4 to 15, with an average of 11.2 alleles per primer. Polymorphic Information Content (PIC) values varied from 0.263 to 0.780, with UBC-843 being the most informative (PIC = 0.780) and UBC-842 the least informative (PIC = 0.263). Cluster analysis using the Unweighted Pair Group Method with Arithmetic Mean (UPGMA) identified one major cluster and three minor clusters, along with four outgroups. The genotypes showed high genetic similarity, with some clusters exhibiting up to 95% similarity. High-yielding and dwarf mutants clustered closely, while wild types and certain mutants formed out groups with similarities ranging from 71% to 85%. This analysis highlights the utility of ISSR markers in detecting polymorphism and genetic relationships among sorghum genotypes, offering valuable insights for breeding programs focused on enhancing genetic diversity and agronomic traits in sorghum.