THE EFFECT OF STORAGE ON THE GERMINATION AND SEEDLING ABNORMALITIES OF LEEK SEEDS PRIMED AND DRIED BY DIFFERENT METHODS

Seed germination and production of abnormal seedling were used to asse ss the performance of leek seeds primed in polyethylene glycol (PEG 6, 000) solutions in bioreactors or on filter paper, dried by various met hods, and stored for up to 525 days at 10-degrees-C and 40% RH in a co nventional seed store. Different priming treatments caused seed germin ation rates to differ making comparable assessment of abnormal seedlin gs impossible. Therefore, germination was synchronised and seed sample s/treatments were incubated sequentially so that all seedlings reached similar states of growth at assessment making possible objective eval uation of seedling abnormalities. These defects mainly affected the gr owing point of radicles and were categorised as 'primary' or 'advanced ', the sum of which, 'total abnormals' was used to record the performa nce of seeds. Although the seeds (from all treatments) maintained high percentage germination throughout storage, the incidence of abnormal seedlings from treated seeds increased with increase in duration of st orage beyond about 100 days. Experiments on methods and conditions of priming and drying showed that those treatments which increased the ef fectiveness of priming all caused increased numbers of abnormal seedli ngs after storage. While differences between effective priming treatme nts were minimal, prolonged immersion of seeds (30 d at 5-degrees-C) o r high temperature (60-degrees-C) drying of primed seeds further incre ased the rate of deterioration during storage.