Onion seeds subjected to accelerated ageing showed rapid
decline in overall germinability and seedling vigour (Table 3).
Germination was reduced from 99% to 55% after 10 days of
accelerated ageing (DAA), whereas vigour loss was about 58%
by 8 DAA. These data reinforce the concept that the ageing
seeds lose the ability to develop into uniform and vigourous
seedlings faster than the ability to germinate. The conductivity
of seed leachates increased more than four times by 10 DAA.
Malondialdehyde content increased with degree of seed
deterioration while the activity of free radical scavenging
enzymes viz., peroxidase, catalase and superoxide dismutase
showed inverse relationships with ageing period and direct
proportion to reductions in the seed germination (Table 3).