Abstract:
Seed ageing during storage is one of the main causes of reduction in seed quality and this results in loss of
vigour and failure to thrive. Finding appropriate storage conditions to ameliorate deterioration due to ageing is, therefore,
essential. Ultrastructural changes in cellular organelles during storage and seed germination rates are valuable indices
of damage that occurs during seed ageing. There is increasing interest in Moringa oleifera Lam. because of its multiple
uses as an agroforestry crop. Seeds of this species lose their viability within 6–12 months of harvest but no scientific information
is available on the longevity of seed stored in the fruit (capsules). Inmost undeveloped countries, seeds are still
stored inside the fruit by traditional methods in special handmade structures. In this experiment we tried to simulate
these traditional storage conditions. Capsules of Moringa were stored at ambient room temperature for 12, 24 and 36
months. The ultrastructure, solute leakage and viability of seed were investigated. The ultrastructure of 1-year-old seed
showed no sign of deterioration. It was evident, however, that some cells of the 3-year-old seed had deteriorated. The
remnants of the outer and inner two integuments that remain tightly attached to the cotyledons probably play a role in
seed dormancy. No significant difference was found between germination percentage of fresh and 1-year-old seed. The
germination percentage decreased significantly from 2 years of storage onward. The decrease in seed viability during
storage was associated with a loss in membrane integrity which was evidenced by an increase in electrolyte leakage.
Our findings indicate that the longevity of M. oleifera seeds can be maintained if they are stored within their capsules.
