光照效應對台灣赤楊、山黃麻及構樹種子發芽的影響

Effects of Light on Seed Germination of Three Pioneer Tree Species (Alnus formosana, Trema orientalis, Broussonettia papyrifera)

張乃航(Nai-Hang Chang)

《台灣林業科學》 11卷2期 (1996/06) Pp. 195-199

https://doi.org/10.7075/TJFS.199606.0195

摘要

省產三種先驅樹種，台灣赤楊(Alnus formosana)，山黃麻(Trema orientalis)和構樹(Broussonetia papyrifera)在恒溫(25℃)及變溫(35℃-15℃，8h-16h)，不同之光質、光照時間及暗期處理下進行種子發芽試驗，其結果顯示，這三種樹種種子發芽可能是受到光敏素(phytochome)調節的。也就是Pr(符號略)Pfr的模式，其中台灣赤楊不論是在恆溫或變溫下，都是絕對需光的，且對光的敏感度根高。在林冠之下仍有部份種子會因為斑光的刺激而發芽。山黃麻及構樹種子則不是絕對需光的。變溫條件下，此二種種子可以在黑暗中發芽，恆溫條件下，山黃麻種子無法發芽，但構樹種子可以在較長期的暗期培養中發芽，兩種子對光的敏感度較低，微光無法刺激其發芽。經由樹葉，林冠層及不同顏色玻璃紙濾過的光線，會對三種種子產生抑制效果，但是將其移到正常日光下時，種子就可以順利發芽。

關鍵字

光敏素 ； 好光性 ； 變溫

並列摘要

The germination behavior of the seeds of 3 pioneer species, Alnus formosana, Trema orientalis, and Broussonettia papyrifera, these seeds was studied under various light and temperature environments. The results indicate that these seeds are regulated by the Pr(符號略)Pfr phytochome reaction. Alnus seeds absolutely need light for germination, and they are highly sensitive to light. A very weak spotlight can trigger germination of Alnus seeds. Trema and Broussonettia seeds are less sensitive to light; seeds of both species can germinate in an alternating temperature regime (35℃/8h-15℃/16h) without light stimulation. Broussonettia seeds can also germinate in the dark at a constant temperature after a prolonged incubation period. All thee kinds of seeds were unable to germinate under the cover of leaflitter, and also when covered with blue or blue and colored plastic paper. Once the seeds are exposed to full sunshine, they germinate rapidly.

並列關鍵字

phytochome ； light-favored seeds ； alternating temperatures