The effects of mechanical and chemical treatments on dormancy breaking and seed germination indices of Myrtus communis L.

Myrtus communis (Myrtle) is an important medicinal plant in traditional medicine and cosmetic industry. This plant grows as evergreen shrub at slope regions and prevents soil erosion. Its seeds have elaisosomes, placed in micropile zone after fertilization. Due to dormancy, its rate and percentage of germination is low. This experiment was conducted in Payam nor university of Boshrouyeh, in order to study breaking of seed dormancy and germination of this plant. Seeds of M. communis exposed to different mechanical and chemical treatments including mechanical scarification with sand paper, sulfuric acid 90%, alcohol 96%, potassium nitrate acid 6% and H2O2 2%, each 10 minutes and untreated seeds as control. The results showed significant differences (P<1%) for all traits, including rate and percentage of germination, length of radicle and plumule, seed growth potential and germination energy. Mechanical scarification and sulfuric acid increased percentage of germination significantly (P<5%) in several traits except for germination index. The root-shoot ratio was more in all treatments than control. We concluded the type of seed dormancy is primary and inducible type that related to physical characters of seed coat.