【作者】 徐克章；

【导师】 张荣铣；

【作者基本信息】 南京农业大学 ， 植物学， 2003， 博士

【摘要】 人参、西洋参为多年生草本阴生植物，是吉林省特有和大面积引进栽培种植的名贵中药材。其产量低、生长周期长一直是限制人参、西洋参生产的关键因素。为了阐明人参、西洋参光合作用和干物质生产特性，为高产栽培实践提供理论依据，用红外线CO₂分析仪、稳态气孔仪、光学和电子显微技术，并结合常规生理生化分析技术，对不同生境条件下，以及植物生长室、人工气候箱和光照培养室内生长的人参、西洋参叶片光合作用对光强、光质和温度响应特性、叶片结构和超微结构、叶绿素含量以及光合作用的生育期变化和日变化进行了比较系统的研究，主要结果如下： 1．对六种透光率（LTR）荫棚下长成的人参叶片结构和超微结构的研究表明，在5％、10％和20％三种LTR荫棚下人参叶片叶面积、叶片厚度、比叶重、单位叶面积叶肉细胞数目、叶肉细胞内表面积随着光强的增加而增加，其中5％LTR荫棚下人参叶片显著（显著水平达0.01）低于其它透光率荫棚下叶片。20％、30％和40％三种LTR荫棚下叶片形态结构特征的变化并不明显，50％LTR荫棚下叶片呈明显下降变化。5％LTR荫棚下叶片叶绿体片层系统发达，叶绿体内淀粉粒稀少，随着光强的增加叶绿体内片层系统减少，淀粉粒增多变大，以50％LTR荫棚下叶片叶绿体内片层系统最少，叶绿体内淀粉粒最多最大。 人参叶片叶绿素含量以10％LTR荫棚下最高，随着光强的增加叶绿素含量下降，叶绿素a／b比值增加，叶绿素含量在50％LTR荫棚下叶片达到最低。10％、30％和50％三种LTR荫棚下西洋参叶片叶绿素含量的测定结果也表现与人参叶片相同的变化趋势。 人参叶片在5％、10％、20％和30％四种LTR荫棚下，西洋参叶片在10％、20％和30％三种LTR荫棚下，叶片光合速率、光合作用的光补偿点和光饱和点随着光强的增加呈显著性增加变化，30％和40％LTR荫棚下长成叶片光合作用特性基本一致，50％LTR荫棚下叶片光合速率略有下降。田间荫棚下叶片光合速率的测定结果普遍低于室内饱和光下叶片的测定结果，其中，人参叶片在5％、10％和20％三种LTR荫棚下，西洋参叶片在10％和20％两种LTR荫棚下，田间荫棚下叶片所测的光合速率显著低于室内所测叶片的光合速率。30％、40％和50％三种透光率荫棚下叶片，在田间荫棚下和室内饱和光下所测光合速率结果差异并不明显。 2．蓝、紫光对人参、西洋参茎叶生长有抑制作用，蓝、紫光下植株提前两周左右衰老，其中以紫色光下最为明显.红、绿光对植株茎叶生长有促进作用，但绿光下叶片展叶时间推迟2一3d。叶片叶绿素含量以蓝、紫光下最高，白、绿光下次之，红、黄光下最低;叶绿素a/b比值以蓝、紫光下最低，红、绿光下最高;与白光下叶片相比，蓝、紫光和黄光下叶片较厚，叶肉细胞层数和单位面积细胞数目增加，而红、绿光下则较低;在低光强（70似Em一，s一，）下，蓝、紫光下和红光下叶片光合作用和光合效率最高，白光下次之，黄、绿光下最低。饱和光下，各种光质下叶片光合作用基本一致。不同光质下，叶片光合作用的光饱和点有差异、以黄、绿光下最高，白、红光下次之，蓝、紫光下最低。 3.人参叶片光合作用适宜温度为15一27℃，西洋参叶片光合作用的适宜温度为20一32℃。不同生长阶段叶片光合作用对温度的响应特性有变化，展叶期至绿果期的叶片不仅光合速率较高，对温度变化的响应也敏感;红果期和黄叶期的叶片不仅光合速率较低，对温度变化的响应也不敏感。 在不同温度条件下培养的人参、西洋参植株叶片也表现为随着生长期间温度的变化，光合作用的温度响应也发生相应适应性变化的趋势。用室内不同温度条件下培养的人参、西洋参植株叶片研究表明，生长期间温度增加5一6℃，光合作用的适宜温度增加2一3℃。叶片光合作用和呼吸作用对温度的响应特性也有差异，当温度低于15℃时，呼吸作用的变化不大，随着温度的增加，呼吸作用增加，在35一38℃时达到最大值，此后随着温度的增加，呼吸作用下降。西洋参叶片光合作用和呼吸作用的C02交换比值，光合作用效率均比光合作用的适宜温度低5℃左右。由此推测，人参、西洋参生长的最适宜温度要低于光合作用的适宜温度5℃左右。 4.人参、西洋参叶片完全展开后，叶片光合速率即达到最大值，开花期叶片光合速率略有下降，绿果期出现第二个高峰，此后随着果实的成熟，光合速率呈持续性下降。弱光下和适宜光照条件下，绿果期后叶片光合速率下降较小，强光下叶片光合速率下降较大，叶片出现早衰。叶片光合效率在绿果期后也呈下降变化，但在叶片完全展开后至绿果期叶片光合效率基本稳定。叶片气孔导度和蒸腾作用在整个生长季节表现与光合速率类似的变化趋势，但绿果期后叶片光合速率的下降较大，气孔导度和蒸腾作用的下降较小。对不同生长阶段胞间C02浓度的分析表明，胞间C0:浓度以绿果期最低，红果期和黄叶期依次上升，说明绿果期后叶片光合速率的下降属于非气孔限制，气孑匕导度的变化在于实现叶片对水分的最优化矛」用。不同生长阶段叶片光合速率的变化可能与植株对光合产物的需求有关，比叶重（SLw）与光合速率（Pn）呈?更多还原

【Abstract】 Panax ginseng (Pg) and Panax quinquefolium (Pq) are famous herb medicine which are planted at large area in Jilin province. As poly-year shade medicine crops, both Pg and Pq are growing very slowly. It will take at least four years in Pq and at least six years in Pg, the yield is very low and it is a limitation factor for the production of Pg and Pq. In order to investigate the characteristics of photosynthesis and matter production, and provide physiological basis of high yield culture in Pg and Pq follow photosynthetic, physiological and structural characteristic were studied;(1) Microstructure and ultra structure of Pg leaves grown under different light conditions were observed under light microscope and electronic microscope.(2) Response characteristic of photosynthesis and photosynthetic efficiency (Apparent Quantum Yield, AQY) to light intensity, light quality and temperature during the growth were measured by model Beckman 865 and QGD-07 infrared gas analyzer.(3) Changes of different growth stage and diurnal of photosynthesis, stomatal conductance, transpiration, water usage efficiency (WUE) and intercellular CO2 concentration (Ci) under different growth region were measured infrared gas analyzer and model Li-1600 stable porometer.(4) Chlorophyll content, starch content, soluble sugar content were analyzed by normal chemical method.The main results are as follows:1. The light intensity during the growth for Pg was arranged with 5%, 10%, 20%, 30%, 40% and 50%, six light transmission rate (LTR) shades; and Pq was arranged with 10%, 20%, 30%, 40% and 50%, five LTR shades. Leaf growth, microstructure, ultrastructure chlorophyll content and photosynthetic characteristic were studied with leaves grown under different light conditions. Specific leaf weight (SLW), leaf thickness, number of mesophyll cell and surface area of mesophyll cell per unit leaf area were increased as the increase oflight intensity grown under 5%, 10% and 20% LTR shades in Pg leaves. Changes of leaf structure were not obvious in leaves grown under 20%, 30% and 40% LTR shades, and SLW, leaf thickness, number of mesophyll cell per unit leaf area and surface area of mesophyll cell per unit leaf area were showed decreased changes in leaves grown under 50% LTR shade. The system of granum lamella in chloroplast was well developed in leaves grown under 5% LTR shade, as the increase of light intensity the system of granum lamella was decreased in leaves grown under 20% to 50% LTR shades. Highest chlorophyll content were measured in leaves grown under 10% LTR shade, as the increase of light intensity, chlorophyll content was decreased and chlorophyll a/b ratio was increased.Starch grain in chloroplast as a product of photosynthesis, were changed dramatically under different light conditions. There was almost no starch grain in chloroplast in the leaves grown under 5% LTR shade, as the increase of light intensity, the size and number of starch grain were increased in chloroplast. Under 50% LTR shade, most of space of chloroplast was occupied by starch grain, the maximum diameter of starch grain was in 3 to 4um in chloroplast.Net photosynthetic rate (Pn), light compensation point and light saturation point were increased as the increase of light intensity in leaves of Pg grown under 5%, 10%, 20% and 30% LTR shades and Pq grown under 10%, 20% , 30% LTR shades. Photosynthetic characteristic was nearly same in leaves of Pg and Pq grown under 30% and 40% LTR shades. Pn in leaves of Pg and Pq grown under 50% LTR shade was showed slightly decreased.2. Growth of stem length and leaf area in Pg were inhibited grown under blue and violet light, and were promoted under red and green light. The stem and leaf grown under yellow light were same as those grown under white light. There were higher total chlorophyll content, chlorophyll b content, leaf thickness and number of mesophyll cell per unit leaf area grown under blue and violet light than those grown under other light quality. Under low light intensity (70uE m-更多还原