Molecular insights into the genetic diversity of Curcuma longa L.: a comparative study with RAPD, ISSR and scot markers

Turmeric (Curcuma longa L.), a perennial medicinal plant cultivated globally, possesses significant economic importance. This study employed molecular markers, including RAPD, ISSR, and SCoT to examine genetic diversity and evolutionary relationships among turmeric cultivars. The study utilized 10 RAPD, 13 ISSR, and 13 SCoT markers, which generated 77, 78, and 126 amplified alleles, respectively. A total of 281 alleles were produced, comprising 243 polymorphic and 38 monomorphic alleles, with an overall polymorphism percentage of 86.47%. Amplicon sizes ranged from 100 to 3000 base pairs. RAPD markers exhibited the highest polymorphism rate (89.25%), followed by SCoT (84.22%) and ISSR (82.05%). The Polymorphic Information Content (PIC), employed to assess each marker’s discriminatory power, ranged from 0.16 (ISSR07) to 0.84 (S6). Mean PIC values were 0.46 for RAPD, 0.43 for ISSR, and 0.47 for SCoT markers. A dendrogram constructed using the UPGMA method, based on combined marker data, revealed two distinct clusters: a major cluster comprising 11 cultivars and a minor cluster consisting of 3 cultivars. Pitamber and Rajendra Sonia were identified as the most closely related cultivars(au: 79, bp: 58; edge #: 1), while PTS55 and Salem varieties exhibited the least similarity. SCoT markers delivered the highest efficiency in Curcuma longadiversity analysis (MI = 3.50), RAPD offered broader polymorphism coverage (MI = 2.89), and ISSR excelled in detecting highly specific loci (MI = 2.10). Combining top-performing primers across systems provides a powerful, precise, and comprehensive approach for germplasm characterization, breeding, and conservation. These findings enhance our understanding of turmeric’s genetic variability, providing valuable insights for crop improvement strategies, germplasm characterization and future plant breeding initiatives.=