Germination of Euryops arabicus Casso Compositae from Asir Mountains, Saudi Arabia PDF

Keywords

Saudi Arabia, botany, seedlings

Abstract

Euryops arabicus is a perennial shrub whose distribution in Saudi Arabia is limited to the high mountainous region (2280- 3000 m above sea level) of the southern region and south Hijaz. The freshly harvested seeds were germinated over a range of alternating (12 hourly) temperature regimes; 18/8, 21/10, 28/14, 32/16, 36/21 and 40/26 C. The geobotanical distribution of E.arabicus is reflected in its germination temperature responses. The germination of the seed of E. arabicus is not regulated by genetically fixed innate dormancy. However, the germination temperature responses of the seeds of the species serve as a mechanism specific to environmental cues, which indicate the probability of favourable conditions for subsequent growth and seedlings establishment. The ecological significance of the temperature responses of the seeds is discussed.