摘要
用盆栽和遮阴试验研究了露水草（Ｃｙａｎｏｔｉｓ ａｒａｃｈｎｏｉｄｅａ Ｃｌａｒｋｅ） 的光合作用特征，比较了不同遮光水平对光合速率、光合器官特性及光合产量的影响。结果如下：１．露水草是一种耐阴偏阳的Ｃ３ 类草木植物，其光合作用的光饱和点约为６５０ μｍ ｏｌ·ｍ － ２·ｓ－ １，光补偿点约为１７ μｍ ｏｌ·ｍ － ２·ｓ－ １，且具有高达１３０×１０－ ６的ＣＯ２ 补偿点。２．露水草的最大净光合速率为１２．４５ μｍ ｏｌ·ｍ － ２·ｓ－ １。叶片净光合速率的日变化规律呈双峰曲线，主峰在１１～１２ 时，次峰在１５时左右。３．遮光２０％ ～５０％ 有利于露水草的生长。与对照相比，叶片中叶绿素ｂ 的含量增加了４７％ ～８３％ ，并且由于净光合速率（相对光合速率）的提高，使光合生产量增加了１２％ ～１８％ 。
The photosynthetic characteristics of Cyanotis arachnoidea Clarke was studied through shading experimentation in pot culture.The effect of different shade level on the photosynthetic rate,the characteristics of photosynthetic organs and the bio production of C.arachnoidea were compared.The main results are as follows: 1.C.arachnoidea was a C 3 type solaphilic and shade tolerant herb.Its light saturation point was about 650 μmol·m -2 ·s -1 and the light compensation point was about 17 μmol·m -2 ·s -1 .Its CO 2 compensation point was about 130×10 -6 . 2.The maximum net photosynthetic rate of C.arachnoidea was about 12.45 μmol·m -2 ·s -1 .The diurnal variation regularity of its photosynthetic rates exhibited a double peak curve in which the main peak appeared during 11∶00～12∶00,and the second around 15∶00. 3. 20%～50% shading favored the growth of C.arachnoidea.In comparison with those with control treatment,the content of chlorophyll b with 20%～50% of shading treatment increased by 47%～83%,and the photosynthetic production increased by 12%～18% as a result of increase in the net photosynthetic rate (relative photosynthetic rate).
关键词
露水草
鸭舌草科
光合作用
生态学
Cyanotis arachnoidea
Photosynthetic characteristics
Shade effect
