Biochimie et physiologie : accès libre

Abstrait

Limitation of Improvement in Germination by Osmopriming of Differentially Aged Non-Orthodox Neem (Azadirachta indica) Seeds

Vimal Pandey, Atanu Kumar Pati

This work involves physiological and biochemical features of seed ageing gauged from seed viability and vigour over the period of storage. Both conventional storage (natural ageing) and controlled deterioration (accelerated ageing) are resulted in loss of germination capacity and vigour as well as poor seedling establishment. Present findings indicate that both natural and accelerated ageing sustain similar pattern, except their mortality curve. In natural ageing, prior to entering sigmoidal type decline a period of relative stability exists; whereas in accelerated aging, such relative stability is absent. It is also observed that rate- controlling process of ageing (natural ageing slow whereas accelerated ageing fast) was dependent upon moisture content and temperature. These physical factors have negative linear correlation with seed viability. Membrane integrity and lipid peroxidation are associated with seed ageing, however peroxidation does not hold exact with accelerated ageing. Additionally, these aged seeds were exposed to osmopriming (controlled hydration) resulted in improved germination characterized by faster and uniform germination. For the first time, it was strongly established that osmopriming significantly improves the seed germination (about 12- 17%) until a critical level (up to 50% germination) during the ageing and thereafter priming does not support the process of improvement of germination. Such improvement prediction is important for physiologists and seed technologists to recruitment the degree of priming.