Abstract:
The objective of the study
was to determine the responsible factors for
germination and early seedling growth due
to salt toxicity or osmotic effect and to
optimize the best priming treatment for
these stress conditions. To study the effect
of osmopriming and hydropriming on
germination and seedling growth of black
cumin (Nigella sativa L.) under salt stress
conditions this experiment was conducted at
Torbat-Heydariyeh University, Torbat, Iran.
The treated seeds (control, hydropriming
and ZnSO4) of black cumin were evaluated
at germination and seedling growth for
tolerance to salt (NaCl and Na2SO4)
conditions at the same water potentials of
0.0, -0.3, -0.6, -0.9 and -1.2MPa. Electrical
conductivity (EC) values of the NaCl
solutions were 0.0, 6.5, 12.7, 18.4 and 23.5
dSm-1, respectively. Results showed that
hydropriming increased germination and
seedling growth under salt stress.
Germination delayed in both solutions,
having variable germination with different
priming treatments. In NaCl treatment,
germination percentage, root and shoot
weight, shoot and root length were higher
but mean germination time and abnormal
germination percentage were lower than
Na2SO4, at the same water potential. The
root / shoot weight and R/S length enhanced
with increase of osmotic potential in both
NaCl and Na2SO4 solutions. NaCl had less
inhibitor effect on seedling growth than the
germination. It was concluded that
inhibition of germination at the same water
potential of NaCl and Na2SO4 resulted from
salt toxicity rather than osmotic effect. The
findings of this experiment can be useful
and applied to achieve best germination and
uniform emergence under field conditions
for farmers of medicinal plants.
