土壤鹽度對欖李苗木葉綠素螢光反應及呼吸作用之影響

Effects of Soil Salinity on Chlorophyll Fluorescence and Respiration of Mangrove Lumnitzera racemosa Seedlings

范貴珠(Kuei-Chu Fan) ； 許博行(Bor-Hung Sheu) ； 張峻德(Chun-Te Chang)

《台灣林業科學》 17卷3期 (2002/09) Pp. 323-335

https://doi.org/10.7075/TJFS.200209.0323

摘要

本研究探討不同土壤鹽分濃度對欖李(Lumnitzera racemosa)苗木葉綠素螢光反應及呼吸作用之影響。苗木以0、0.75、1.5及3.0% NaCl四種不同鹽度處理40、55、75及90 d後，以葉綠素螢光分析儀測定其光合活性。結果顯示在處理75及90 d後，0.75及1.5%二處理苗木暗適應後之最大PSⅡ光化學光量子產量(Fv/Fm)及PSⅡ潛在活性(Fv/Fo)明顯較0及3.0%處理者高，表示其葉片PSⅡ光化學活性較高。苗木之光化學淬熄係數(qP)則以0.75、1.5及3.0%三種處理較高，顯示PSⅡ反應中心氧化態之QA比例增加，有利於光合作用之電子傳遞；然3.0%處理苗木之非光化學淬熄係數(qN)明顯較高，而且葉片之光量子產量(Ф11)明顯較低，即PSⅡ反應中心所捕獲之光能，以非光化學反應之熱能散失機會增加。而四種不同鹽度處理苗木150 d後，0、0.75及1.5%三種處理苗木之葉片呼吸作用速率並無顯著差異，但3.0%高鹽度處理者則明顯增加。而苗木根部呼吸作用則以0.75及1.5%二種鹽度處理者較低，0及3.0%高鹽分處理苗木則較高。上述結果可說明欖李苗木在低鹽分濃度下，會有較佳之生長及生理表現。

關鍵字

紅樹林 ； 欖李 ； 鹽度 ； 葉綠素螢光反應 ； 呼吸作用

並列摘要

This study investigated the effect of different salinities on chlorophyll fluorescence and respiration of mangrove Lumnitzera racemosa seedlings. Seedlings were grown in different concentrations of salinity containing 0, 0.75, 1.5, and 3.0% NaCl each for 40, 55, 75, and 90 days. The effects of salinity on photosynthetic activity in seedlings were determined using a pulse amplitude-modulated chlorophyll fluorometer. The quantum yield of PS Ⅱ photochemistry in a dark-adapted state (Fv/Fm) and the potential activity of PS Ⅱ (Fv/Fo) were significantly higher in seedlings grown in both 0.75 and 1.5% NaCl compared to those treated with 0 and 3.0% NaCl after 75 and 90 days of treatment. The photochemical quenching coefficients (qP) were higher with 0.75, 1.5, and 3.0% treatments compared to 0%-treated seedlings, reflecting the capacity of PS Ⅱ reaction centers to compete for the Chl-excited state; it is related to the redox states of QA The non-photochemical fluorescence quenching (qN) of seedlings grown in 3.0% salinity increased and the quantum yield decreased, indicating that the reduction in quantum yield was due to increased heat dissipation. Foliar and root respiration rates were measured in seedlings grown in different salinities for 150 days. Although foliar respiration rates of seedlings grown in 0, 0.75, and 1.5% NaCl treatments did not differ, they significantly increased at 3.0% salinity. Root respiration rates were lower in the 0.75%-and 1.5%-treated seedlings compared to those of 0%-and 3.0%-treated ones. These results explain the better growth and physiological performance of seedlings of L. racemosa when grown in mild salinities.

並列關鍵字

mangrove ； Lumnitzera racemosa ； salinity ； chlorophyll fluorescence ； respiration