Diversity of Sweet Basil Accessions from Croatian National Plant Gene Bank Based on Amplified Fragment Length Polymorphism Markers

This study investigates genetic diversity among five morphotypes and five chemotypes of Ocimum basilicum L. (sweet basil) using amplified fragment length polymorphism (AFLP) markers. Conducted on 80 basil accessions from the Collection of Medicinal and Aromatic Plants of the National Plant Gene Bank of the Republic of Croatia, this research aims to enhance the conservation and utilization of sweet basil’s genetic resources. AFLP analysis using extracted genomic DNA revealed high levels of polymorphism, particularly within the True basil morphotype, which displayed 95.6% polymorphic markers. The results showed genetic differentiation between the morphotypes, particularly between the ’green’ and ’purple’ groups, and within certain chemotypes, such as the High-linalool chemotype (Chemotype A). Principal coordinate analysis (PCoA) and Bayesian clustering further highlighted the genetic structures, with some admixture observed, particularly in the Purple basil B morphotype. Analysis of molecular variance (AMOVA) indicated that most of the genetic diversity was between accessions, emphasizing the value of individual variability. These findings underscore the genetic potential within sweet basil accessions, offering valuable insights for future breeding programs aimed at selecting basil cultivars with tailored biochemical and morphological traits suited for pharmaceutical, culinary, and ornamental applications. The study provides an important basis for the conservation and improvement of basil genetic resources.