【摘要】 将黄瓜（ Ｃｕｃｕｍｉｓｓａｔｉｖｕｓ Ｌ．） 幼苗培养在相同辐照度（２０ μｍｏｌ·ｍ － ２·ｓ－１） 的白光、红光和蓝光下，研究了光质对黄瓜叶片的光合作用特性的影响。实验结果表明，生长在白光下的叶片，其叶绿素（Ｃｈｌ）含量分别比红光和蓝光下高７ ％ 和２２４％ ，在蓝光下的含量最低。生长在红光下的黄瓜叶片有较低的Ｃｈｌａ／ｂ 比值和较高的Ｃｈｌ ｂ 含量。低温（７７ Ｋ）荧光发射光谱和Ｃｈｌａ 荧光动力学诱导的实验结果表明，红光下的叶片具有较高的光系统Ⅱ（ＰＳⅡ） 活性和较低的光系统Ⅰ（ＰＳⅠ）活性，蓝光下的叶片具有较低的ＰＳⅡ活性和较高的ＰＳⅠ活性。红光下叶片的放Ｏ２ 速率比白光下叶片的放Ｏ２ 速率高４４９％ ，而蓝光下的叶片放Ｏ２ 速率略低于白光下的。表明光质对调节黄瓜叶片ＰＳⅠ和ＰＳⅡ的发育和光合活性以及光合放Ｏ２ 速率具有重要作用。更多还原

【Abstract】 Cucumber (Cucumis sativus L. cultivar “Changchun Mici”) seedlings were cultured in Hoagland solution under irradiation with different light spectra (8 h per day) for 20 days. The red light (λ max 658 nm, λ 1/2 25 nm), blue light (λ max 450 nm, λ 1/2 43 nm) and white fluorescent light possessed the same fluent rate (20 μmol·m -2 ·s -1 ). The experimental results showed that chlorophyll content of the leaves grown under white light was 7% and 22.4% higher than those in red and blue light, respectively. Compared with white and blue light, red light induced a lower Chl a/b ratio and a higher level of Chl b in the cucumber leaves. Measurements of the low temperature (77 K) fluorescence emission spectra and kinetics of Chl a fluorescence induction of the leaves proved that the leaves grown under red light expressed the highest PSⅡ and the lowest PSⅠ activities while the leaves under blue light had the lowest PSⅡ and the highest PSⅠ activities. The O 2 evolution rate of red light_grown leaves was 44.9% higher than that of the white light_grown leaves, while blue light effect was similar to that of white in respect of O 2 evolution. It is concluded that light quality is an important factor in regulating the development and activities of PSⅡ and PSⅠ and the O 2 evolution of photosynthesis in cucumber leaves.更多还原