含水率與儲藏溫度對烏心石種子可儲藏性之影響

Effect of Moisture Content and Storage Temperature on the Storability of Seeds of Michelia compressa (Max.) Sargent

林讚標(Tsan-Piao Lin)

《台灣林業科學》 11卷4期 (1996/12) Pp. 373-384

https://doi.org/10.7075/TJFS.199612.0373

摘要

本文旨在探討烏心石種子在不同種子含水率與儲藏溫度下對儲藏壽命的影響並探討烏心石種子的後熟現象。烏心石種子於1993年分別採自南庄、棲蘭與孝義。在乾燥儲藏於相對濕度94% r.h、75% r.h、40% r.h、35% r.h與14% r.h.下，種子之含水率分別保持在13.6%±1.5%，11.5%±1.2%，7.8%±1.5%，6.3%±1.3%與4.7%±1.3%（鮮重為基準）。新鮮烏心石種子所具有的特徵是休眠現象，並且在乾燥與乾藏過程中維持休眠。在經過18個月的儲藏中觀測到：恆溫下，種子之含水率愈低，種子壽命愈長：在35%~40%相對濕度下，儲藏的溫度愈低，種子壽命愈長。6.3%的含水率或以下，種子在-20℃儲藏發芽率可維持至少18個月不墜。烏心石種子含水率15%時，種子敗壞甚速，在儲藏4個月內喪失80%至100%之發芽率。低溫濕藏種子亦可維持至少一年之發芽率。濕藏處理一方面破除休眠現象，也可以大為縮短種子達到最高發芽率之50%所須時間(G50)，儲存半年之後G50縮短至小於兩個星期。乾藏亦可略為縮短G50之時間。新鮮成熟烏心石種子在乾藏的最初一個星期內有明顯的後熟作用，G50在此一期間內亦呈大幅縮短，此一現象在低(5℃)高(25℃)溫均可發生，但高溫則維持了較大幅度的後熟現象。若以儲藏較長時間的觀點看，當種子含水率於12%或種子平衡於75% r.h.時之後熟作用較為不明顯。低於此後熟作用明顯。當種子儲藏於94%相對濕度與4℃下種子在儲藏之前幾個月期間發芽率遠較75%相對濕度為高，而且G50也顯著短於低相對濕度的種子，此一現象我們暫稱為礙層積現象。

關鍵字

烏心石 ； 種子生活力 ； 種子可儲藏性

並列摘要

Seeds of Michelia compressa were collected from Nanjung, Chilan and Shiauhyi in 1993. Moisture contents of 13.6%±1.5%, 11.5%±1.2%, 7.8%±1.5%, 6.3%±1.3% and 4.7%±1.3% (fresh weight basis) were maintained for seeds dry stored at 94% r.h., 75% r.h., 40% r.h., 35% r.h., and 14% r.h., respectively. Fresh mature seeds were characterized by dormancy which prevailed over the dry storage condition. With an 18-month storage period, it was found that at a constant storage temperature, germination was better maintained at a lower moisture content. At relative humidities of 35%-40%, longevity was better maintained at a lower storage temperature. Seed germinability could be kept for at least 18 months at moisture contents of 6.3% or less and at -20℃. Seeds of M. compressa were also characterized with high deterioration rates at high storage temperatures; at a moisture content of 15% and 15℃, seeds lost 80% to 100% of their germinability within 4 month of storage. Cold and wet storage kept the germinability at least for 1 year. In addition to breaking dormancy, cold wet storage could reduce the time of reaching 50% of the final germination (G50) to 2 weeks after the seeds were stored for half a year. Dry storage only slightly reduced After-ripening of mature M. compressa seeds occurred extremely fast in the first week of dry storage, and at 25℃ the seeds had a higher germination rate and lower G50 than at 5℃. On a longer time scale, after-ripening was less obvious at a seed moisture content around 12% or when the seeds were equilibrated to a relative humidity of 75%. M. compressa seeds stored at 94% relative humidity, had much higher germination rates than those stored at 75% relative humidity in the first several months of storage; also seeds stored at 94% relative humidity had significantly lower G50 than those stored at the other 3 relative humidities. It is considered that this phenomenon mimics the effect of stratification.

並列關鍵字

Michelia compressa ； seed viability ； seed storability