THE SURVIVAL OF GERMINATING ORTHODOX SEEDS AFTER DESICCATION AND HERMETIC STORAGE

Seeds of barley (Hordeum vulgare L.) and mung bean (Vigna radiata (L.) Wilczek), with orthodox seed storage behaviour, were imbibed for between 8 h and 96 h at 15-degrees-C and 25-degrees-C, respectively, while barley seeds were also maintained in moist aerated storage at 15-degrees-C for 14 d. These seeds and seedlings, together with controls, were then dried to various moisture contents between 3% and 16% (wet basis) and hermetically stored for six months at -20-degrees-C, 0-degrees-C or 15-degrees-C. In both species,. neither desiccation nor subsequent hermetic storage of the control lots resulted in loss in viability. The results for barley seeds imbibed for 24 h were similar to the control, but desiccation sensitivity increased progressively with duration of imbibition beyond 24 h in barley or 8 h in mung bean: these treatments also reduced the longevity of the surviving seeds in air-dry storage. Loss in viability in barley imbibed for 48 h was most rapid at the two extreme seed storage moisture contents of 3.6% and 14.3%, and in both these cases was more rapid at 15-degrees-C than at cooler temperatures. Similarly, for mung bean imbibed for 8 h, loss in viability was most rapid at the lowest (4.3%) moisture content, but in this case it was more rapid at -20-degrees-C than at warmer temperatures. Thus, these results for the storage of previously imbibed orthodox seeds conform with the main features of intermediate seed storage behaviour.