Physical seed dormancy in Lepechinia floribunda (Lamiaceae): a medicinal native shrub.

Abstract

Physical seed dormancy in Lepechinia floribunda (Lamiaceae): a medicinal native shrub. Lepechinia floribunda is an aromatic and medicinal shrub with multiple uses. The low germination of its seeds is the main limiting trait for propagation. The goal of this study was to test the presence of physical seed dormancy in L. floribunda and to assess the effectiveness of time of storage and different pregermination treatments in order to overcome such dormancy. We conducted an imbibition experiment and tested germination in seeds stored for 0, 90, 270, and 1050 days, which were subjected to pretreatments of thermal (water at 100°C) and chemical scarification (sulphuric acid). Seeds of L. floribunda have physical dormancy, and the most effective treatment to break it was sulphuric acid, surpassing 70% of germination. Time of storage did not affect the state of dormancy, and the viability of seeds was maintained high for at least 3 years. Results from this study will help to establish strategies of sexual propagation of this native useful plant species.