Creation of rosemary germplasm resources with high glandular trichome density and elevated levels of volatile and non-volatile functional components

Abstract

Rosemary originates in the Mediterranean region and is a traditional medicinal and aromatic plant. It contains a variety of bioactive components, including both volatile and non-volatile, and exhibits properties such as antioxidant, anti-inflammatory, anti-tumor, anti-fungal, and anti-viral effects. As the demand for rosemary continues to rise, existing resources are insufficient to meet people’s needs. In this study, we identified two rosemary varieties that exhibited significant differences in leaf glandular secretory trichome (GST) densities, as well as the volatile and non-volatile components. Using these two varieties as parents, we performed crossbreeding to generate F 1 hybrid progenies. Based on haplotype-based whole-genome sequencing (Data unpublished), 200 pairs of SSR molecular markers were developed. Using these markers, the hybrid authenticity of the F 1 lines was assessed, and three F 1 lines were confirmed. Subsequently, these three F 1 lines were self-crossed to construct F 2 lines. From these, 56 true hybrid progenies were identified using SSR marker. By observing GST densities in the parents, F 1 and F 2 lines, and seven promising germplasm resources with higher GST densities than both parents were selected. The volatile and non-volatile functional components of the parents, F 1 and F 2 lines were also determined. As a result, several promising germplasm resources with high levels of volatile and non-volatile components were created, providing a foundation for the selection and breeding of high-yield and high-quality new varieties. This work will also lay the groundwork for the construction of a genetic linkage map, localization QTLs related to important functional components and their yield in rosemary.