【作者】 胡婧楠；

【导师】 刘桂华；

【作者基本信息】 安徽农业大学 ， 园林植物与观赏园艺， 2010， 硕士

【摘要】 光合作用是绿色植物利用光能进行能量转化和形成有机物的过程,因受到外界环境条件和内部因素的影响而发生变化。本文采用美国LI-COR公司生产的LI-6400便携式光合作用测定系统,对安徽枞阳县大山珍稀树种园内华东楠(Machilus leptophylla Hand.-Mazz.)和桢楠(Phoebe zhennan S.Lee et F.N.Wei)幼树以及安农大校园内紫楠(Phoebe sheareri Hemsl. Gamble)在自然条件下春、夏、秋、冬四个季节的净光合速率和相关生理生态因子进行测定,同时测定三种楠木的光-光响应曲线,分析影响三种楠木净光合速率的生理生态因子;测定三种楠木叶片内叶绿素a、叶绿素b的含量和比叶重,分析三种楠木的耐阴性;测定三种楠木鲜叶和枯叶的养分含量,并分析其与净光合速率的相关关系。主要结果如下:1、在自然状态下,三种楠木在不同季节的净光合速率日变化有两种类型,夏季和秋季呈双峰曲线,有“午休”现象,春季和冬季呈单峰曲线。以观测期内三种楠木最大净光合速率和日均净光合速率综合分析其净光合速率水平,由大到小排列为紫楠>华东楠>桢楠。2、分析不同季节三种楠木的光-光响应曲线,华东楠和桢楠具有较低的光补偿点(10.89μmol/m~2·s、15.93μmol/m~2·s),利用弱光能力较强,有一定的耐阴性,紫楠具有较高的光饱和点(1100μmol/m~2·s),利用强光能力较强。3、结合通径分析和逐步回归分析影响三种楠木净光合速率的生理生态因子,光合有效辐射(PAR)、大气温度(Ta)以及气孔导度(Cond)、蒸腾速率(Tr)、叶片水压亏缺(Vpdl)是影响净光合速率的主要因子,并且在不同季节影响净光合速率的因子具有复杂性和不稳定性。4、不同季节三种楠木的水分利用率(WUE)无明显变化规律,光能利用率(LUE)的季节动态变化为冬>夏>秋>春,影响夏季光能利用率的主要因子是光合有效辐射(PAR)和蒸腾速率(Tr)。5、分析不同季节三种楠木的叶绿素a、叶绿素b含量和比叶重(LMA),叶绿素a/b的季节动态变化为秋>夏>春>冬,三者中华东楠叶绿素a/b最低,为1.7256,三者相比具有最强的耐阴性。比叶重与三种楠木净光合速率呈显著正相关关系,其相关系数分别为0.7678,0.8901和0.8777。6、测定不同季节三种楠木的叶片养分含量,分析叶片特征参数与净光合速率的关系,结果表明,华东楠和桢楠的磷含量(P)与净光合速率呈极显著相关关系,相关系数达到0.8283和0.8191;紫楠的氮含量(N)与净光合速率呈极显著相关关系,相关系数达到0.7545。更多还原

【Abstract】 Photosynthesis is the process in which the green plants use light energy to transform its energy and form organic substance. The process may be changed by environmental conditions. This study mainly tests the four following aspects. Firstly, it tests the net photosynthetic rate of Machilus leptophylla Hand.-Mazz and Phoebe zhennan S.Lee et F.N.Wei. in Zongyang County and Phoebe sheareri Hemsl. Gamble in Anhui Agricultural University in four different seasons by use of LI-6400 portable photosynthetic system produced by the LI-COR Company US. Secondly, the photosynthesis lightresponse curves of the three phoebe plants were tested in order to analyze the genetic controls on tue net photosynthetic rate. Thirdly, it measures the chlorophyll content and the rate of weight to area and analyzed the shade-tolerance nature of the three phoebe plants. Fourthly, it measured the nutrient content of the three phoebe plants’fresh leaf and withered leafage and analyzed the relationship between net photosynthetic rates. The main results are as follows:1. Under natural circumstances, the three phoebe plants’net photosynthetic rate has two different types in different seasons. Two-peak curve was observed in summer and autumn and one-peak curve in spring and winter. Based on the maximum net photosynthetic rate and average daily net photosynthetic rate, the sequence of the three phoebe plants renked as Phoebe sheareri > Phoebe zhennan > Machilus leptophylla.2. By analyzing the photosynthesis lightresponse curve, Machilus leptophylla and Phoebe zhennan showed a lower light-compensation point(10.89μmol/m~2·s、15.93μmol/m~2·s). Phoebe sheareri showed a relatively higher light-saturation point(1100μmol/m~2·s).3. In combination with All-through analysis and progressively-regression analysis, the main controls on net photosynthetic rate were photosynthetically active radiation (PAR), atmosphere temperature (Ta), stomatal conductance (Cond), transpiration rate (Tr) and leaf water deficit (Vpdl). These factors have complexity and instability when they impact net photosynthetic rate.4. In different seasons, the three phoebe plants do not have a distinct change rule in the event of water use efficiency (WUE), while the light use efficiency (LUE) embodies as Winter > Summer> Autumn >Spring. The main genetic in summer is photosynthetically active radiation (PAR) and transpiration rate(Tr). 5. By analyzing the chlorophyll a content, chlorophyll b content and LMA of the three phoebe plants, the seasonal dynamic change of chlorophyll a/b is Autumn > Summer > Spring > Winter. Among the three, Machilus leptophylla has the least chlorophyll a/b (1.7256) and has a relatively strong shade-tolerance nature.The rate of weight to area (LMA) and net photosynthetic rate (Pn) are distinctively related, the correlation coefficients are 0.7678,0.8901 and 0.8777 .6. By measuring the three kinds of Phoebe plants’leaf nutrient concentrations in different seasons and analyzing the relationship between leaf feature parameter and net photosynthetic rate, the result showed that the phosphor us content (P) of Machilus leptophylla and Phoebe zhennan was strongly related to net photosynthetic rate, with correlation coefficients of 0.8283 and 0.819;1and the nitrogen content (N) of Phoebe sheareri was strongly related to net photosynthetic rate, the correlation coefficient is 0.7545.更多还原