Effect of Pre-soaking by distilled water on seeds germination of black seeds (Nigella sativa L.) under salinity stress

Abstract

A laboratory experiment was conducted to study the effects of salinity and presoaking treatments on final germination percentage, days to 50% germination, and recovery percentage of Nigella sativa seeds. Seeds were divided into two groups and for 24h one group was presoaked in different NaCl concentrations (25, 50, 75, and 100 mM), while the other was presoaked in distilled water. They were then sown in Petri dishes and watered with salinity treatments. Results showed high significant difference between the two presoaking treatments. Final germination percentage of seeds of the first group was negatively affected where it decreased as salinity concentration increased. Only seeds at 25 mM reached to 50% of germination after ten days, while those at other concentrations failed. Results also showed that seeds of the second group were germinated well after being exposed to salinity stress. They also achieved more than 50% germination during the first five days of experiment. The recovery percentage of the un-germinated seeds of the two groups was low indicating toxic ionic effect on seed germination and viability. It was concluded that salinity effect on germination traits increases with the increase in concentration and presoaking treatment in distilled water helps seeds to reduce salinity stress.