Abstract:
Seed aging is the main
problem of seed storage. Changes of
enzyme activity and reduction of seedling
growth are consequence of seed
deterioration. An experiment was conducted
to evaluate the effects of accelerated aging
on germination indexes and enzyme activity
of barley seeds. Seeds were incubated in
closed plastic boxes for the accelerated
aging treatments at 41°C. Three accelerate
aging regimes were performed by placing
seeds at 41°C and relative humidity (RH) of
90-100 % for 0, 4 and 8 day periods. Our
results showed that increasing aging
duration resulted higher reduction in
germination percentage, germination index,
mean time to germination, normal seedling
percentage, catalase and ascorbate
peroxidase. The highest germination
percentage, germination index, normal
seedling percentage and enzyme activity
were achieved in control conditions (0 day
of aging). Under aging conditions,
germination percentage, means time to
germination, germination index, normal
seedling percentage and enzyme activity
decrease significantly. Also, our results
indicated that seed aging is related to
decrease of enzymes and may contribute to
low germination efficiency. The general decreases
in enzyme activity in the seed
lowers the respiratory capacity, which in
turn lowers both the energy (ATP) and
assimilates supply of the germinating seed,
also decrease in antioxidant enzymes is
linked to an increased accelerated ageing
and decreased germination characteristics.
Subsequently, proposed a positive
relationship between antioxidant enzyme
capacity and the vigour of the seed.
