Abstract:
Saline soils contain multiple
types of salt, each of them may exert a
different effect on seed germination and
seedling growth. The aim of this study is
to assess the effects of five types of salt
on the seed germination and radicle
establishment of common bean
(Phaseolus vulgaris L. var. Djedida).
The experiment was set out as a factorial
experiment based on completely
randomized design with four replications
of ten seeds for the seed germination and
twelve replicates for the seedling growth.
We used five kinds of salts (NaCl,
Na2SO4, CaCl2, CaCO3 and KCl) with
concentrations of 0, 100, 200 and 300 mM.
Seeds were incubated in Petri dishes at
25°C, in the dark, for 10 days. The results
of analysis of variance indicated that the
effects of salt types and concentrations,
and their interaction effect were
significant in all measured traits (P< 0.01).
However, no significance effect was
found on secondary roots number and
seedlings dry biomass with CaCO3
treatment solution. According to the
results, the inhibitory effects of the five
salt types differed significantly. Indeed,
germination of common bean seeds by
various salts were in the order of NaCl >
KCl > CaCO3 > Na2SO4 > CaCl2.
However, the taproot length, the number
of secondary roots and the seedlings dry
weight by various salts were in the order
of CaCO3 > KCl > NaCl > CaCl2 >
Na2SO4. The effect of salt concentration
was also obvious. The reduction in dry
biomass of cotyledons is proportional to
germination rates and to the development
of seedlings in dry biomass and in size.
Seeds of P. vulgaris var. Djedida were
able to germinate under all concentrations
of the various types of salt. The lowest
final germination percentage (FGP) was
obtained under 300 mM of all salts
recording the following values: CaCO3 -
60%, NaCl - 60%, KCl - 52.5%, Na2SO4 -
50% and CaCl2 - 27.5%. During germination stage, the radicle emergence
would be controlled by the environment
osmolarity, while the later growth of the
seedling would be limited by the reserve
mobilization.
