溫度對台南市雙春地區欖李光合作用及螢光反應之影響

EFFECT OF TEMPERATURES ON PHOTOSYNTHESIS AND FLUORESCENCE RESPONSE OF LUMNITZERA RACEMOSA IN SHUANGCHUN AREA OF TAINAN CITY

王經文(Ching-Wen Wang) ； 詹鈞皓(Chun-Hao Chan) ； 翁韶良(Shau-Lian Weng) ； 廖天賜(Tien-Szu Liao)

《中華林學季刊》 51卷4期 (2018/12) Pp. 347-368

摘要

欖李（Lumnitzera racemosa）為台灣原生種僅分布於台南地區，本研究擬探討欖李自然分布侷限於台灣南部之原因是否受溫度之影響，因此，以台南市雙春地區之材料為研究對象，設定15-35℃等5種溫度條件，溫度選擇為該週平均氣溫在15、20、25及30℃時進行量測，另35℃則以儀器提高溫度量測，測定其對光合作用速率及葉綠素螢光等生理活性之影響。結果顯示此地區欖李之光合作用速率會受到氣孔與非氣孔因素之限制而降低，其中光化學效能之PSII電子傳遞速率（ETR）、PSII開放程度（qP）、PSII光量子產量（ΦPSII）及PSⅡ最大光化學效能（Fv'/Fm'），皆明顯隨著溫度下降而降低，在15℃時出現最低，表示光合作用的光反應系統亦受到低溫之抑制。在光保護方面，欖李之可溶性蛋白、葉綠素a+b、類胡蘿素在≤20℃時具有較大的含量，分別為6.68、0.42與0.09 mg g^(-1)，其中可溶性蛋白含量的增加為提升其抗寒能力，非增加光合作用速率；又低溫高光的情況下，於15℃光抑制達到31.8%之最大值，且qE/NPQ值同時下降至18.7%的最低點，顯示欖李光合系統的生理活性受15℃低溫環境的影響而降低，這或許是欖李在台灣的自然分布侷限於南部的原因之一。

關鍵字

欖李 ； 溫度 ； 光合作用 ； 葉綠素螢光 ； 光抑制

並列摘要

Lumnitzera racemosa is indigenous species to Taiwan only distributed in Tainan. This study explores why the natural distribution of L. racemosa is limited to the southern part of Taiwan, is the effect of temperature? Therefore, the materials in the Shuangchun area of Tainan City are the research objects. We set five temperature conditions, such as 15-35℃. The temperature is selected to be the average temperature of the week at 15, 20, 25, 30, and 35℃ to increase the temperature of the instrument, to measure their effects on the physiological activity of photosynthesis and chlorophyll fluorescence. The results show that the photosynthesis rate is reduced by the limitation of stomatal and non-stomatal factors. The photochemical efficiency of ETR, qP, ΦPSII and Fv'/Fm' decreased significantly with decreasing temperature, and the lowest at 15℃, indicating that the photoreaction of photosynthesis system was also inhibited by low temperature. In terms of light protection, the soluble protein (6.68 mg g^(-1)), chlorophyll a+b (0.42 mg g^(-1)), and carotenoid (0.09 mg g^(-1)) of L. racemosa have a large content at 20℃ or less, and the increase of soluble protein content is to improve their cold resistance, not to increase the photosynthesis rate. In the case of simultaneous low temperature and highlights, the photoinhibition in 15℃ reaches a maximum of 31.8%, and the qE/NPQ value simultaneously drops to the lowest point of 18.7%. It is shown that the physiological activity of the photosynthetic system is reduced by the low temperature environment of 15℃, which may be one of the reasons why the natural distribution of L. racemosa in Taiwan is limited to the south.

並列關鍵字

Lumnitzera racemosa ； Temperature ； Photosynthesis ； Chlorophyll Fluorescence ； Photoinhibition