Seed dormancy and germination in Dodonaea viscosa (Sapindaceae) from south-western Saudi Arabia

Saudi Journal of Biological Sciences

B.S. Al-Ammari¹  A.J. Davy²  A.A. Al-Namazi³  T.A. Al-Turki⁴ 

[1] Corresponding author.;Imam Mohammad ibn Saud Islamic University, College of Science, Biology Department, Saudi Arabia;King Abdulaziz City for Science and Technology (KACST), Box 6086, Riyadh 11442, Saudi Arabia;School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK;

关键词: Dodonaea viscosa;    Dormancy;    Light response;    Physical dormancy;    Salinity (NaCl);    Seed germination;   

DOI  :  

来源: DOAJ

【 摘 要 】

Dodonaea viscosa (Sapindaceae) is widespread in the mountainous highlands of the southwestern part of Kingdom of Saudi Arabia, where it is a medicinally important species for the people in Saudi Arabia. Seeds of this species were collected from Mount Atharb in Al-Baha region, at an altitude of 2100 m. The aims of this study were to determine if the seeds of D. viscosa have physical dormancy (i.e. a water-impermeable seed coat) and, if so, what treatments would break dormancy, and what conditions promote germination after dormancy has been broken. The dormancy-breaking treatments included: soaking of seeds in concentrated sulfuric acid (H2SO4) for 10 min, immersion in boiling water for 10 min and exposure to 50 °C for 1 min. After seeds had been pre-treated with H2SO4, to break dormancy, they were incubated at constant temperatures from 5 to 35 °C, under 12-h photoperiods or in continuous darkness, and germination recorded. Salinity tolerance was investigated by incubating acid-scarified seeds in different concentrations of mM NaCl in the light at 25 °C.Untreated seeds had low final germination 30%. Seeds that had been acid-scarified, immersed in boiling water or exposed to 50 °C all achieved 91% subsequently when incubated at 25 °C. Thus, seeds of this species in Saudi Arabia have physical dormancy, which can be broken by all three treatments designed to increase the permeability of the testa. After pre-treatment, there was a broad optimum constant temperature for germination that ranged between 5 and 25 °C but germination was inhibited by higher temperatures (30 and 35 °C). Light had little effect on this germination response. Scarified seeds were also sensitive to salinity, with the highest germination in distilled water and complete inhibition in 400 mM NaCl. Seeds that failed to germinate in saline treatments were mostly able to germinate on transfer to distilled water, suggesting osmotic inhibition.

【 授权许可】

Unknown