白桕與茄苳種子的儲藏性質

Seed Storage Behavior of Sapium discolor Muell.-Arg. and Bischofia javanica Blume

楊正釧(Jeng-Chuann Yang) ； 林讚標(Tsan-Piao Lin) ； 郭幸榮(Shing-Rong Kuo)

《台灣林業科學》 21卷4期 (2006/12) Pp. 433-445

https://doi.org/10.7075/TJFS.200612.0433

摘要

本研究目的在明瞭白桕與茄苳種子的發芽特性，並探討其儲藏性質。白桕種子採於高雄縣多納，新鮮種子以30/20℃（8h光照）變溫條件經16週後之發芽率為59%，以4℃層積處理解除休眠所得之發芽數據評估本批種子潛在的發芽率為85.3%，故本批種子約有30%具深度休眠。以4℃層積經1~8mo均能完全解除白桕種子休眠，且發芽速度會隨著層積時間的延長而顯著增快，平均發芽日數從新鮮種子的54d下降到層積1mo後的41d，再下降到層積7mo後的23d。白桕種子的含水率降低至1.8~7.9%（鮮重），儲藏在-20~15℃經24mo後仍不失活力，故判定其儲藏性質屬正儲型。
茄苳種子採於台北縣三峽，新鮮種子在30/20℃（8h光照）變溫條件經8週後發芽率為78%，平均發芽日數僅10~18d，且能在4週內完成發芽，顯示此種子不具休眠性。茄苳種子含水率被乾燥到5.3~12.5%後大部分種子仍能存活，但儲藏在-20℃時，含水率在3.7~12.5%範圍的種子在24mo後活力均顯著下降。茄苳種子儲藏在-20、4與15℃時其含水率最適界分別是8、5~13與5~8%。儲藏溫度以4℃較能維持種子活力，明顯優於-20與15℃。評估茄苳種子的最佳儲藏條件是將含水率8%的種子儲存於4℃環境中。茄苳種子能忍耐乾燥但對零下低溫敏感，此特性顯示其儲藏性質是介於正儲型與異儲型間的中間型。

關鍵字

白桕 ； 茄苳 ； 層積 ； 正儲型種子儲藏行為 ； 中間型種子儲藏性質

並列摘要

The storage behavior and germination characteristics of seeds of Taiwan tallow tree (Sapium discolor) and Javanese bishopwood (Bischofia javanica) were investigated in the present study. The germination percentage of freshly collected mature seeds of S. discolor from Duona, Kaohsiung County in 1997 was 59% over 16 weeks under alternating temperatures of 30/20℃ with 8h of light. With cold stratification of freshly collected seeds for 2mo, the germination percentage reached as high as 85.3%. Therefore, about 30% of seeds showed deep dormancy. The mean germination time was reduced from 54 d for freshly collected mature seeds to 41d after 1mo of stratification. Seed germinability of S. discolor could be maintained at -20~15℃, for at least 24 mo at MCs (moisture contents) of between 1.8 and 7.9% (on a fresh-weight basis). These results confirm that S. discolor seeds exhibit orthodox seed storage behavior.
The germination percentage of freshly collected mature seeds of B. javanica from Sansia, Taipei County in 1997 was 78% over 8 weeks under alternating temperatures of 30/20℃ with 8 h of light, and the mean germination times were between 10 and 18 d. Most freshly mature seeds survived when they were desiccated to 5.3~12.5% MCs; however, the viability of those seeds with 3.7~12.5% MCs dropped significantly at -20℃ after 24 mo of hermetic storage. The optimum seed moisture contents of B. javanica were 8, 5~13, and 5~8% for -20, 4, and 15℃ storage, respectively. The temperature effect on seed longevity revealed that the longevity of seeds stored at 4℃was better than those at -20 and 15℃. We estimated that the optimum seed storage conditions for B. javanica are provided by combining a temperature of 4℃ with about an 8% MC. These results confirm that B. javanica seeds exhibit intermediate storage behavior that is characterized as being tolerant to desiccation but sensitive to freezing temperatures.

並列關鍵字

Sapium discolor ； Bischofia javanica ； stratification ； orthodox seed storage behavior ； intermediate seed storage behavior