Seed germination characteristics of some medicinally important desert plants from the Arabian Peninsula

摘要: The arid climate of Saudi Arabia supports many medicinally important species. Germination behavior is crucial to their establishment in the face of low rainfall and high summer temperatures that produce high evapotranspiration and salt accumulation in the surface soil. We investigated the seed germination biology of three medicinal species from Wadi ad Dayqah in central Saudi Arabia: Salvia spinosa (Lamiaceae), Ochradenus arabicus, and Ochradenus baccatus (Resedaceae). We examined the responses of freshly collected seed to constant and alternating temperature, light, and salinity (NaCl). None of the species showed innate dormancy. All achieved high germination percentages over a wide range of diurnally alternating temperatures (5/15, 10/20, 15/25, 20/30 and 25/35 °C). However, the range of temperature for successful germination was narrower at constant temperature, especially for S. spinosa. The …