Part1
在墾丁海域內，每年3-6月正是多數藻類的大量繁生期。根據觀察，在所有的大型藻類中，以匍匐生長的食用松藻覆蓋珊瑚礁的比例最高。但到了7-9月間，生長在亞潮帶5公尺以上的食用松藻覆蓋率即明顯下滑；過了11月之後，亞潮帶的食用松藻族群又慢慢回復，直到隔年3月才又開始大量繁生。到目前為止，尚無任何針對食用松藻在7-9月間其族群大量鋭減的原因進行探討。因此，本研究即對此一生態現象，由形態及生理方面著手，做一初步的研究。
本實驗利用葉綠素螢光作為食用松藻在逆境之下其生理變化的指標；在形態觀察方面，則是利用電子顯微鏡觀察在環境逆境之下食用松藻細胞內部微細結構所發生的變化。我們發現到食用松藻在33℃下，其光合作用雖然會失去光週期性，但仍然能夠維持一個定值，整株藻體的外觀並沒有很明顯的變化，顯示出33℃對食用松藻的葉綠素螢光有影響，但並不足以造成細胞死亡。
將溫度提升至35℃時整株藻體才會開始發生不可逆的傷害。在35℃之下，我們發現到在30分鐘之內食用松藻的光飽和點及電子傳遞速率明顯高於25℃環境下的食用松藻，顯示細胞的光合作用會在短時間內快速提升。經過3-5小時後，整個藻體結構已經產生不可逆的軟化現象。隨後出現的是葉綠素螢光快速地下降，而在8-10小時之後，葉綠素的螢光已經無法偵測到；另外根據形態觀察，我們也發現在35℃環境下4小時之後，細胞內的液泡已經開始縮小，並有許多小囊泡的產生，使得細胞逐漸失去支撐力而出現軟化，這應是決定細胞死亡的關鍵。到6小時之後，整個細胞發生了質離現象，細胞膜的結構也受到破壞，失去其完整性，顯示細胞已經出現了壞死的現象。
綜合以上的發現，我們可以確定暴露在35℃的海水中，會使食用松藻的細胞結構造成不可逆的破壞，而液泡的瓦解是造成食用松藻死亡的主要原因。

PartII
本實驗是藉由穿透式電子顯微鏡來觀察同步化的Chlorella pyrenoidosa小細胞在經過46℃的熱處理後，置於連續光照的環境之下，細胞逐漸死亡的過程。
在熱處理後的Chlorella細胞內首先發生的是染色質體濃縮並聚集在細胞核的周圍，顯示加熱對小球藻細胞產生的立即性影響。將經過加熱處理的小球藻置於光照環境下6小時後，小球藻因為葉綠素的分解而有明顯白化的現象，相對應於電顯切片的結果，雖然此時類囊膜結構都還很完整，膜並未受到破壞，但類囊膜間的顆粒狀結構已經消失。在光照的第8小時，我們已經看不到細胞內液泡、粒線體內膜及核仁的結構，而葉綠體的類囊膜結構也在這段時間由細胞內部開始向外部瓦解。顯示在光照第6~8小時之間是細胞形態發生變化的最大期，隨著這些胞器的消失，細胞質緊接著開始濃縮，由於細胞壁、細胞膜並未破裂，而導致質離現象的發生，而到光照第12小時達到最大數量，但質離現象會隨時間經過而逐漸變得不明顯；除此之外，染色質體仍然持續濃縮而形成一個空心環狀，此一現象可以維持一段相當長的時間。
綜合以上的觀察，可以確定小球藻在經過高溫處理後置於連續光照的環境下培養，會導致細胞內部機制所引發的細胞死亡，並有其一定的死亡過程，有別於因細胞膜破裂引起的細胞壞死。

PartI
The growth period for many macroalgae in Ken Ting is from March to June. According to preview studies, Codium edule has the largest covering ratio on the coral reef among all the macroalgae, but its population above 5m depth of subtidal drastically decreases from July to September. After November C. edule gradually recover and rapid growth state until March next year. In this article, we use the chlorophyll fluorescence and transmission electrons microscopic（TEM） to find out the possible reasons for C. edule drastically decrease between July to September.
According to chlorophyll fluorescence studies, we found that C. edule lost photosynthetic circadian rhythm at 33℃, but it was not lethal at the temperature. Upon exposure to 35℃, the photosynthetic activity of the algae would drastically decrease after 4 hours and drop to zero after 8 hours. From TEM studies, the vacuoles reduce in size which was accompanied by the appearance of many small vesicles after exposing to 35℃ about 4 hours. In the meantime, the algae became soft and underwent plasmolysis that is believed a key induced cell death. Finally, the vacuole collapsed completely and the plasmamembrane destroyed which means the algal cells started to necroses.
In summery, our data suggested that 35℃ would cause the vacuole to collapse and lead to C. edule is cell death. This might be for the reason it drastically decrease between July to September.

PartII
In this study, we examined the programmed cell death （PCD）of synchronous Chlorella pyrenoidosa culture by transmission electron microscopic（TEM）. The PCD started right affect high temperature stress（46.5℃）followed by continuous illumination under normal culture condition.
We noticed that high temperature stress induced chromatin condensation around the inner membrane of nuclear and something in vacuole. These phenomena elucidated the immediate effect on Chlorella brought about by heat stress. In 6 h after stress we found that Chlorella cell were bleached. But according to the images of TEM, the destruction of the thylakoids started at 8 h but not at 6 h. The direction of thylakoid destruction was from inner to outer side of Chlorella cells. At the same time, the structures of vacuole, mitochondria and nuclei in Chlorella also disappeared. These showed that there were dramatic morphological changes in Chlorella between 6-8h. The disappearances of organells were followed by and then the cytosolic condensation which in turn induced plasmolysis, but the later phenomenon would vanished gradually. In addition, the chromatins condensation formed an annular structure that was preserved for more than two days.
In summery, Chlorella would die after heat treatment. The death was induced by a spontaneous mechanism and a programmed process different from ordinary.

Part I
蔡娟娟 （2000） 營養鹽與溫度對墾丁南灣大型海藻生物量之影響

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