弱光胁迫下普通油茶岑软3号苗期光合速率及生长特性研究

Study on the Photosynthetic Rate and Growth Characteristics of Camellia oleifera Cenruan 3 in Seedling Stage under Low Light Stress

为了更好的研究弱光下油茶（Camelliaspp．），幼龄期光合及生长特性，对岑软3号苗期进行不同强度（60％、75％和90％）的遮荫处理，180天后调查结果表明：60％、75％和90％遮荫条件下岑软3号日平均净光和速率分别为3．60、3．17和2．42μmol／（m2·s），分别为对照的70．81％、62．49％和47．70％，均大于相对应透光率，遮荫处理后叶片光合能力增强；60％～90％弱光对岑软号苗期茎和叶片生长抑制作用不明显，而75％遮荫条件下岑软3号根系的干物质积累受到影响；弱光下叶片生长朝着更有利于捕捉光能的方向，叶片叶绿素a、叶绿素b以及类胡萝卜素都显著增加，且色素合成中优先合成了叶绿素。

Camellia oleiflera Cenruan 3 were shaded 60 % , 75 % and 90 % light, to better research the photosynthetic and growth characteristics in seedling stage under low light stress. After 180 days, the results of the survey showed that the daily average net photosynthetic efficiency of 60 %, 75 % and 90% shading treatment reached 3.60μmol/ （m2s）, 3.17 μmol/ （m2·s） and 2.42 μmol/ （m2s） respectively, taking up 70.81%, 62.49 %, and 47.70 % of control, which were greater than the cor- responding light transmittance, and that shading treatment could increase photosynthetic ability; un- der 60 % -- 90 % low light, it was not obvious to inhibitate the growth of stem and leaf of Cenruan 3 in seedling stage, while the accumulation of root dry matter was affected under the condition of 75 % shading treatment; under low light, leaf growed toward more conducive direction to capture the light, the chlorophyll a, chlorophyll b and carotenoids significantly increased, and the synthesis of chlorophyll was priority in the synthesis of pigment.