Germination and Storage Behavior of Seeds of Scaevola taccada (Gaertner) Roxb.

草海桐種子的發芽與儲藏性質

楊正釧(Jeng-Chuann Yang) ； 郭幸榮(Shing-Rong Kuo)

《台灣林業科學》 33卷1期 (2018/03) Pp. 17-30

https://doi.org/10.7075/TJFS.201803_33(1).0002

摘要

The purpose of this study was to examine the germination characteristics of seeds of Scaevola taccada. Effects of the seed moisture content (MC) and storage temperature on germination were investigated to determine its seed storage behavior. Results showed that seeds of S. taccada were non-dormant. The majority of fresh mature seeds germinated during 2~5 wk under fluctuating temperatures of 30/20℃ with 8 h of light, and few seeds irregularly germinated in the subsequent 5~20 wk. It was speculated that the difference in germination speed was related to the degree of seed maturity. Moreover, stratification at 4℃ neither improved germination nor decreased the mean germination times (MGTs) of seeds of S. taccada. In other words, stratification at 4℃ is not practical for nursery operations because it cannot promote more-uniform germination. Besides, the seeds faced a great risk of dying during moist storage at 4℃ for more than 3 mo; thus, moist storage at 4℃ should not be applied to short-term storage of seeds of S. taccada. However, seeds of S. taccada dried to 1.9~5.9% MCs (on a fresh-weight basis) still maintained viability after 2 yr of storage at -20, 4, and 15℃. Seeds of S. taccada can tolerate desiccation and sub-zero temperatures, which qualifies them as orthodox. In short, seeds of S. taccada can be stored over a long-term period to assure future seed supplies. If seed storage of S. taccada is used for plant germplasm collection and long-term conservation, we recommend that seeds of S. taccada should be dehydrated to 3~7% MCs and then hermetically sealed before storage at -20℃.

關鍵字

Scaevola taccada (Gaertner) Roxb. ； germination ； orthodox ； seed storage behavior ； stratification

並列摘要

本研究探討草海桐種子的發芽特性，並以種子含水率與儲藏溫度對發芽率之影響來判定其種子儲藏性質。結果顯示草海桐種子不具休眠性，當新鮮的成熟種子以30/20℃變溫發芽時，大多數會在第2～5週中發芽，但可能有少數種子會在第5～20週零散發芽，推斷此與種子成熟度有關。4℃層積無法有效提升草海桐種子的發芽率，亦無法降低其平均發芽日數使其在短期內整齊發芽，即4℃層積處理在本種的育苗作業上不具實用價值，而且當4℃濕藏時間超過3個月後就有大量死亡的危險，故4℃濕藏並非短期儲藏本種種子的可行方法。當草海桐種子被乾燥至含水率1.9～5.9%，在-20、4與15℃經二年儲藏後活力仍未有下降趨勢，顯示其能耐乾燥且耐零下低溫環境，故判定其屬長壽命的正儲型，亦即可將種子進行長期儲藏以供日後利用，建議未來以儲存種子來進行本種種源的收集與長期保存時，應先將種子含水率降低到3～7%，然後密封儲藏在-20℃環境中。

並列關鍵字

草海桐 ； 發芽 ； 正儲型 ； 種子儲藏性質 ； 層積