Abstract:
Astragalus armatus Willd.
subsp. armatus is an endemic shrub of the
Northern Africa. Its cultivation and
domestication are very limited because of
difficulty with seed germination and
establishment. In this study, we investigated
some plant morphological characteristics
in real time and in situ (leaves, fruit
and seeds) of different ecotypes of
A. armatus, collected from two sites in
Algeria (Arid Steppe of Aïn Naga and
Condorcet Mountain), which elevation
and climate data are very different.
Moreover, the role played by the seed
coat in seed dormancy of these two
different populations was tested by the
effects of the pretreatment and its duration
on the performance of seed germination,
by considering the final germination
percentage (FGP) and the mean germination
time (MGT). These parameters are
estimated for 10 days in Petri dishes and
stored in darkness at (25°C). Pre-sowing
treatments included immersion in
concentrated sulphuric acid for 30, 60 and
90 min, and immersion in hot water
(100°C) for 10 min. Statistical analysis
showed that the treatment and the ecotypes
effects on both FGP and MGT were
highly significant (p< 0.0001). Untreated
seeds of both ecotypes of A. armatus
failed to germinate (except for a few of
Condorcet Mountain ecotypes). For both
populations, the most effective treatment
was immersion in sulphuric acid for
60 min for the ecotype of Arid Steppe of
Aïn Naga, and only 30 min for Condorcet
Mountain. An excellent germinative
strength is characterized by a higher FGP
and a reduced MGT. The morphological
characteristic and seed germination could
be attributed to intraspecific variations
resulting from the natural selection of the
same species.
