温室生菜的光合特性及环境参数优化的试验研究

为探明温室生菜的光合作用与温室小气候之间的量化关系,以实验为基础,研究春、夏季玻璃温室条件下生菜的光合特性,分析温度、光照、ＣＯ２浓度、湿度等环境因子对光合作用的综合影响,初步建立了生菜的光合生产函数,从而可对环境因子进行优化组合以合理利用和调控气象资源测定和优化结果表明：生菜的光合速率在一定范围内随着光强和ＣＯ２浓度的增加而增加,但有一定的极限;夏季的光合速率日变化呈双峰曲线,在启用风机＋湿帘降温系统的情况下无午休现象;夏季较合理的调控参数为：温度３３℃,光强３５０００ｌｘ,相对湿度７５％     

短期高温对牡丹叶片光合作用及相关生理指标的影响

以3年生盆栽牡丹"洛阳红"为试材,研究了短期高温胁迫下牡丹叶片膨大期叶片的光合作用和几种生理指标的变化.结果表明,短期高温处理后,牡丹叶片净光合速率(Pn)及可溶性蛋白质、叶绿素、游离脯氨酸(Pro)含量分别比对照上升27.53%,74.86%,34.49%,8.79%,而气孔导度(Gs)、胞间CO2质量浓度(Ci)、蒸腾速率(Tr),丙二醛(MDA)含量分别比对照下降28.05%,61.9%,19.57%.短期适度的高温并不会对牡丹的生长造成不良影响.     

Distribution of lanthanum among the chloroplast subcomponents of spinach and its biological effects on photosynthesis： location of the lanthanum binding sites in photosystem Ⅱ

The effects of lanthanum at different concentrations on the related photosynthetic activities of Hill reaction, Mg^2＋-ATPase and Ca^2＋-ATPase in spinach chloroplast were studied. Experimental results showed that lanthanum can increase all the activities at suitable concentration （15-30 mg· L^-1）, however, it behaves toxically on them when over used （60 mg. L^-1）. To get an improved understanding of the mechanism of lanthanum effects on the photosynthesis of spinach, the different subcomponents in the chloroplast of the cultured spinach were isolated, and the content of lanthanum in each subcomponent was determined by ICP-MS. The results obtained indicated that among these different subcomponents, about 90% out of the total chloroplast lanthanum was located in photosystem Ⅱ （PS Ⅱ） while there was little lanthanum in photosystem Ⅰ （PS Ⅰ）. Moreover, size exclusion high performance liquid chromatography （SE-HPLC） coupled with online UV and ICP-MS detections was novelly used for locating lanthanum binding sites in PS Ⅱ proteins for the first time. It was found that lanthanum has two binding sites in PS Ⅱ： La associates with chlorophyll together with magnesium in PS Ⅱ by partly replacing magnesium and also shares the common binding sites of PS Ⅱ proteins together with the inorganic cofactors of calcium and manganese, influencing the process of photosynthesis.     

高寒地区地膜覆盖栽培饲用甜菜光合日变化初探

高寒地区饲用甜菜光合速率日变化呈现明显的双峰型,在上午10时和下午14时分别有两个高峰,且第二高峰低于第一高峰,在中午12时有一低谷,出现“光合午休”现象.相对湿度(RH)日变化呈双峰型,高峰和低谷出现的时间与光合速率(Pn)吻合.叶片温度(T1)日变化呈单峰型,高峰出现的时间为上午10时.覆膜饲用甜菜光合速率在第一高峰与对照差别明显,第二高峰差别不明显.     

紫细菌光合作用原初反应中的超快光动力学过程研究 (Ⅰ)--紫细菌捕光天线系统LH2

主要综述了紫细菌捕光天线系统LH2中的超快光动力学过程及相关的物理机制等方面的研究进展。     

Hypoosmotic shock induces a stateⅠtransition of photosynthetic apparatus in Dunaliella salina

The effects of hypoosmotic shock on state transition in darkness in Dunaliella salina were studied. When the concentration of NaCI in culture medium was dropped from 1.5 to 0.5 mol/L abruptly, the photosynthetic rate of D.salina declined, but the respiratory rate and intracellular ATP content increased in the dark. The FpsⅡ/FpsⅠ ratio at 77 K of D. salina cells exposed to hypoosmotic shock was higher than that of control cells, indicating that more excitation energy was distributed to PS Ⅱ in stressed D.salina cells upon illumination. A decrease in LHC Ⅱ phosphorylation level was also observed when D.salina was exposed to hypoosmotic shock. Thus a state Ⅰ transition of photosynthetic apparatus occurs when D.salina suffers hypoosmotic shock in darkness, which is supposed to be related to an enhancement of respiration and an increase in ATP content in stressed D.salina cells.     

城市森林生态系统太阳辐射能利用分析

城市自然环境本底的改变对城市森林的生长发育有深刻的影响．城市森林生态系统接受太阳辐射的强度、光照时间都小于自然环境下的最大可照时间，确定城市环境中不同立地树木可获得太阳辐射强度和光照时间，对提高城市森林生态系统太阳辐射能利用效率，发挥城市森林的功能和作用有重要意义．在调查分析的基础上，提出了城市森林两类不同立地环境下太阳辐射能利用的计算方法．     

光照对坛紫菜生长和无机碳利用的影响

］以坛紫菜Z-61品系为研究材料,分析坛紫菜叶状体和丝状体在三种光强（10,50,500 μmol·m-2·s-1）下的应答。发现:1）坛紫菜叶状体和丝状体的光系统 Ⅱ 最大量子产量及叶绿素a和藻红蛋白的含量都随光强增加而降低,但净光合速率、最大光合速率、胞外碳酸酐酶活性和总碳酸酐酶活性则随光强增加而增加。2）当光强从10 μmol·m-2·s-1增加到500 μmol·m-2·s-1时,坛紫菜叶状体的生长速率约增加77%;丝状体的生长速率先增加后降低,在光强500 μmol·m-2·s-1下达到最低,比在10 μmol·m-2·s-1下显著下降了约90%。3）在三种光强下,坛紫菜叶状体的最大光合速率、光系统 Ⅱ 最大量子产量和生长速率都大幅高于丝状体。这些结果表明:坛紫菜的光系统 Ⅱ、光合作用与生长对光强的应答并不完全一致;叶状体比丝状体更适应高光,这可能是长期进化的结果;光强可以改变坛紫菜对无机碳的吸收。     

田间增加UV-B辐射对丝瓜光合作用日变化及水分利用效率的影响

在自然条件下，增加不同强度的UV—B辐射，对攀援植物丝瓜叶片光合速率日变化和水分利用效率进行了研究，发现经增加R1强度UV—B辐射处理的丝瓜的净光合速率和蒸腾速率比对照上升了28％和33％，水分利用效率则下降了3．4％，而经增加R2强度UV—B辐射处理的丝瓜的净光合速率和蒸腾速率比对照上升了47％和13％，水分利用效率也上升了28％，且其光合作用不受午间强光的抑制，光合午休现象消失了．这表明，在该实验的UV—B强度下，丝瓜的光合作用不但未受抑制，反而还增强了，说明适当增加UV—B辐射对丝瓜的生长有利．     

在模型建构中开展的一堂高三生物专题复习课——《光合作用和呼吸作用》一节的课例分析

从模型建构入手,对高三专题复习《植物光合作用和呼吸作用》一节的教学进行了课堂整体设计,以期训练学生建立模型时抽象化或具体化的思维过程.