Chemical and molecular diversity of rosemary (Salvia rosmarinus L.) clones

In recent years, rosemary received more attention in India for its essential oil, fresh herb, and dry herb. Hence, it is very much essential to assess the genetic diversity for the development of new high-yielding cultivars and also for germplasm characterization, conservation, and utilization in a breeding program. In the present study, 24 clones were used to assess the chemical and inter simple sequence repeat (ISSR) based genetic diversity. The analysis of variance based on chemical constituents showed significant differences among the clones for chemical components, and 24 progenies were grouped into four chemotypes groups viz.,1,8-cineole type (18.59-35.19%), verbenone type (2.71-15.70%), camphor type (3.12-29.86%), and alpha-pinene type (4.33-27.71%). Thirteen ISSR primers produced 6.51 average polymorphic bands with 58.26% percent polymorphism. The cluster analysis, using the unweighted pair group method with Arithmetic mean (UPGMA) tree method, classified the 24 rosemary progenies into three major clusters at a coefficient of 0.24. Even though the chemotype and molecular grouping were different, the study's results emphasize that evaluating both chemical and genetic diversity is crucial for successful rosemary cultivation and breeding efforts. The findings contribute valuable insights for further research and development in the field of rosemary cultivation and utilization in India.