Influence of salinity and drought stresses on seed germination and seedling growth characteristics in sesame (Sesamum indicum L.)

Abstract

In the present study, the potential for salt and drought tolerance of sesame genotypes were assessed. Seeds of three registered cultivars (Golmarmara, Muganli-57 and Uzun) were treated to seven levels (0, 25, 50, 75, 100, 150 and 200 mM) of NaCl to determine salinity influence on seeds. The drought condition was provided by Polyethylene glycol (PEG) induced water deficit. Seeds were germinated under stress of aqueous PEG solutions mixed to create water potentials of -2, -4, -6, -8 and -10 MPa. Effects of these abiotic stresses were assessed with the use of germination rate and early seedling growth traits which were root and shoot length, root fresh and dry weight, shoot fresh and dry weight. There is no germination at -8 and -10 MPa PEG applications for all the cultivars. Increasing concentrations of PEG from -2 to -6 MPa drastically reduced root length and the lowest value was recorded at -6 MPa. The cultivar, The treatment of different NaCl levels showed that increasing salt stress significantly decreased germination rate and seedling growth traits. The traits of the germination rate, root fresh weight and shoot dry weight were less affected at lower levels of salinity. However the concentration of >150 mM NaCI drastically reduced all the studied traits. The overall results suggest that germination and seedling growth traits were strongly inhibited by > -6 MPa PEG and 150 mM NaCl levels therefore lower concentrations should take into consideration for sustainable sesame production.