Germination, storage behaviour and cryopreservation of seeds of Champereia manillana (Opiliaceae) and Schefflera octophylla (Araliaceae) --Effect of cold moist storage on germination

Germination, storage behaviour and cryoperservation were tested for seeds of Champereia manillana and Schefflera octophylla. Freshly harvested, mature seeds of both species germinated > 90% after 3 weeks incubation at 30/20oC. Seeds of C. manillana survived desiccation to 5.6% moisture content (MC) (fresh weight basis) during storage at 4oC for 6 months without loss of viability, which thereafter decreased gradually. However, viability of seeds with a MC ≥ 5.6% decreased more rapidly during storage at 15oC than at 4oC. Survival of seeds stored at -20oC was lower than that of seeds stored either at 4 or 15oC. Nevertheless, maximum viability of Champereia seeds with a MC of 5.6% was maintained in liquid nitrogen (-196oC). Thus, C. manillana exhibited intermediate seed storage behaviour. Seeds of S. octophylla survived desiccation to 6~7% and -20oC storage for 24 months without loss of viability. Seeds of this species with a MC ≤ 6.2% also survived in liquid nitrogen, whereas viability was reduced to about 50% of that of seeds originally dried and not stored in liquid nitrogen. Thus, seeds of this species exhibit orthodox storage behaviour.本研究针对台湾山桂花（Champereia manillana）与鹅掌柴（Schefflera octophylla）的成熟种子，开展了发芽率、贮藏特性及超低温保存（cryoperservation）相关测试。两个物种的新鲜采收成熟种子，在30/20℃条件下萌发培养3周后，发芽率均高于90%。台湾山桂花种子经脱水至含水量（moisture content, MC）5.6%（鲜重基准）后，于4℃贮藏6个月期间未发生生活力流失，此后其生活力逐步下降。但含水量≥5.6%的种子，在15℃条件下贮藏时，其生活力下降速率较4℃贮藏时更快。于-20℃贮藏的种子，其存活率低于4℃或15℃贮藏的种子。不过，含水量为5.6%的台湾山桂花种子，在液氮（liquid nitrogen，-196℃）中可维持最高生活力水平。由此可见，台湾山桂花种子表现出中间型种子贮藏特性。鹅掌柴种子经脱水至含水量6%~7%后，于-20℃贮藏24个月仍未出现生活力流失。含水量≤6.2%的该物种种子同样可在液氮中存活，但生活力仅降至未经液氮贮藏的原脱水种子的约50%。据此可知，鹅掌柴种子表现出正常型种子贮藏特性。