Comparative karyological investigation of four economically important ornamental Jasminum species from Bangladesh

Jasmine (Jasminum spp.) is a flowering plant cultivated commercially in Bangladesh, India, and other Southeast Asian nations like Singapore, Malaysia, and the Middle East. Despite being an economically important genus, reports on karyotypes of these species have been scarce due to the small and sticky chromosomes. Here, four economically important ornamental Jasminum species, namely, J. auriculatum, J. grandiflorum, J. multiflorum, and J. sambac, were cytogenetically studied to evaluate the karyological relationship. J. auriculatum, J. grandiflorum, and J. multiflorum were found to possess 2n=2x=26 (diploid) whereas 2n=3x=39 (triploid) somatic chromosome number was found in J. sambac. These four Jasminum species differed in karyotype formulae such as 24m + 2sm in J. auriculatum, 22m + 4sm in J. grandiflorum, 26m in J. multiflorum and 39m in J. sambac. Based on Stebbins classification, J. auriculatum was positioned in 1A karyotype whereas J. grandiflorum, J. multiflorum, and J. sambac were placed in 1B karyotype. Considering different karyotypic asymmetric parameters, J. sambac and J. auriculatum could be suggested as more primitive over J. grandiflorum and J. multiflorum. The cluster analysis revealed that these four Jasminum species could be grouped into two main clusters and J. sambac was comparatively more distantly related to the others. The above findings could be an important tool for characterization and effective for evaluating karyotype diversity among four Jasminum species.