Temperature Acclimation of Photosynthesis in Meconopsis horridula var. racemosa Prain.

總狀綠絨蒿光合作用的溫度馴化

張石寶(Shi-Bao Zhang)

《Botanical Studies》 51卷4期 (2010/10) Pp. 457-464

摘要

總狀綠絨蒿(Meconopsis horridula var. racemosa Prain.)是世界著名的高山花卉和藏藥資源。由於難于忍受炎熱的夏季，在低海拔處栽培總狀綠絨蒿是困難的。為了評估總狀綠絨蒿在不同溫度下的光合表現及生化、氣孔和葉肉因素對其光合作用的相對限制，我們在三種溫度下研究了其光合氣體交換和葉綠素螢光。結果表明，總狀綠絨蒿植株在20℃下比10℃和30℃下有更高的光合能力及光化學效率，且其在低溫下(10℃)的光合表現要好於高溫下(30℃)。非光化學淬滅是總裝綠絨蒿在溫度脅迫下保護光合機構的重要機制。雖然在低溫和高溫下葉肉導度都是總狀綠絨蒿的重要光合限制因素，但是在高溫下總狀綠絨蒿光合作用還受到氣孔和生化因素的限制。總狀綠絨蒿在高溫下不良的光合表現會限制其在低海拔地方的栽培。

關鍵字

總狀綠絨蒿 ； 高溫 ； 光合作用 ； 葉綠素螢光 ； 光合限制

並列摘要

Meconopsis horridula var. racemesa Prain. is a famous alpine flower and medicinal plant native to high elevations in the Himalayas, but cultivating it at lower altitudes presents great challenges. The photosynthetic gas exchange and chlorophyll fluorescence of M. horridula were investigated at three temperatures to evaluate its photosynthetic performance and the relative importance of biochemical limitation, stomatal limitation, and mesophyll limitation to photosynthesis under different temperature regimes. Meconopsis horridula grown at 20℃ could obtain the highest photosynthetic rate and photochemical efficiency among the three temperatures, and photosynthetic performance at low temperature was better than at high temperature. Non-photochemical quenching was an important mechanism protecting the photosynthetic apparatus of M. horridula under temperature stress conditions. Although mesophyll conductance was the dominant factor for limiting photosynthesis of M. horridula both at low temperature and high temperature, the photosynthesis at high temperature was also limited by stomatal conductance and biochemical efficiency. The poor photosynthetic performance at high temperature may be what limits M. horridula cultivation at low altitude.

並列關鍵字

Chlorophyll fluorescence ； High temperature ； Meconopsis horridula ； Photosynthesis ； Photosynthetic limitation