Evaluating the germination capacity of commercial seedlots of Quercus petraea

About 120 000 kg of sessile Oak acorns (Quercus petraea Liedl.) are collect ed each fall in France. A part of them have to be stored from one year to t he next for a regular production of plants. So far, only laboratory germina tion tests (8 weeks) are used to predict acorn viability. To improve the ma nagement of commercial seedlots and decide whether to store them or not, it would be useful to rapidly asses their viability. In the literature, two p arameters present correlation with viability for artificially dehydrated se eds. We wanted to know if the same correlation existed for commercially sto red acorns. Contrary to artificially dehydrated acorns, the moisture conten t of the embryonic axis of stored acorns does not correlate to the percenta ge of seedlings. A high embryonic axis moisture content (> 60%) is necessar y but not sufficient to indicate good viability of the seedlot. During long duration storage, even if water stress in the embryonic axis is moderate, germination physiology necessitates additional water. Electrolyte leakage d irectly evaluates the effects of this water stress, a decrease in membrane integrity. This test can be a good indicator of viability for acorns after long duration storage.