寶山堇菜 (Viola baoshanensis) 和紫花地丁 (V. yedoensis) 葉綠素熒光參數的日變化

研究了寶山堇菜 (Viola baoshanensis) 和紫花地丁 (V. yedoensis) 葉片葉綠素熒光參數的日變化。紫花地丁NPQ呈單峰型增長，寶山堇菜NPQ有先增加，後下降的趨勢。2種堇菜rETR首先迅速上升，維持在一個較高水平，然後迅速下降，Ik變化趨勢相對一致。紫花地丁Pm和α呈雙峰型變化，寶山堇菜有先增加，後下降的變化趨勢。相關性顯示，寶山堇菜葉片rETR與光合有效輻射呈顯著正相關(P<0.05)。紫花地丁葉片溫度分別與Y、NPQ呈顯著負相關和正相關(P<0.05)，葉表光合有效輻射與Y、NPQ分別達極顯著負相關和正相關(P<0.01)，與rETR顯著正相關(P<0.05)。結果表明，正午時刻2種堇菜光系統Ⅱ遭受了光抑制，熱耗散和光呼吸是紫花地丁的重要光保護機制，寶山堇菜通過光呼吸來保護光合機構。
Diurnal dynamics of photosynthetic parameters of Viola baoshanensis and V. yedoensis were investigated. rETR (electron transport rate) of the two species increased very quickly in morning, and kept at a high level, then decreased. There were difference variation patterns between the two viola species for NPQ, rETR, Pm, I(subscript k) and α, and a significant relationship between PAR and rETR. For V. yedoensi, a significant negative relationship was found between leaf temperature and Y, a significant positive relationship between leaf temperature and NPQ, and a significant positive relationship between PAR and NPQ. The above results showed that excess light energy dissipated via the xanthophyll cycle and large proportion of electrons allocated to photorespiration for V. yedoensi played roles in protecting the photosynthetic apparatuses. For V. baoshanensis, preventing photodamage was mainly through large proportion of electrons allocated to photorespiration. Copyright © 2009 華南師範大學.