麻竹山地笋用林笋期叶片光合及呼吸性状研究

Through analyzing the various position leaves character of 3 ages bamboo, including net photosyntheticrate, light respiratory rate, dark respiratory rate, CO2 compensation point and light compensation point, in five-years - old forest during different growing shoot stages in stated - own forestry farm of Nanjin, results showed thatleaves had vigorous physiological function during prosperity stage of growing shoot. Net photosynthetic rate was high-er, light respiratory rate, dark respiratory rate, CO2 compensation point and light compensation point were lower,the photosynthetic coefficients was larger.2- year bamboo and 3 - year bamboo had stronger photosynthetic ability. Different photosynthetic and respiratory indexes of various position leaves were not consistent, but in generally, mid-dle leaf had stronger assimilation ability.     

Effects of Iron Deficiency on Thylakoid Membrane Structure and Composition in the Alga Dunaliella salina

Abstract

The unicellular green alga Dunaliella was previously proposed as a model photosynthetic organism for adaptation to iron deficiency. The purpose of this study was to find out how iron limitation affects the structure and composition of the photosynthetic system of Dunaliella salina. Iron deprivation did not retard proliferation of D. salina cells, but was associated with a decrease in cell volume and chlorophyll content, and with a four‐fold reduction in iron content and a two‐fold increase in Cu content. Electron microscopic analysis revealed shrinkage of the chloroplast and decrease in stacked thylakoid membranes. Measurements of chlorophyll fluorescence induction in the presence of DCMU and of 77 K chlorophyll fluorescence emission spectra indicated gross changes in the photosynthetic efficiency of reaction centers and in the organization of their associated light harvesting antenna. Differential analysis of protein composition led to the identification of a major thylakoid membrane protein (Tidi), that was specifically induced under iron deprivation. Partial sequencing suggests that Tidi is a novel type of a chlorophyll a/b binding protein. These results clearly show that iron limitation is associated with extensive reorganization of the photosynthetic system in Dunaliella.     

自然强光对阴生植物虎耳草光合特性的影响

采用LI-6400光合测定仪对阴棚内和自然光强下的虎耳草叶片光合特性进行了比较,同时测定了叶绿素的含量。研究发现,阳光下的虎耳草光合速率显著降低,主要受光量子密度的影响;阳光下的叶片总叶绿素含量降低明显,类胡萝卜素却明显升高。     

多效唑对蓝莓干旱胁迫的缓解作用研究

[目的]研究多效唑对蓝莓(Vaccinium uliginosum Linn.)干旱胁迫的缓解作用的机理。[方法]以夏普兰和奥尼尔2个南高丛蓝莓品种为材料,通过提前喷施500 mg/L多效唑,研究多效唑对蓝莓受干旱后的保护效果。[结果]提前喷施多效唑可以减小干旱胁迫下蓝莓叶片的电导率、丙二醛含量、H2O2含量及O2-.含量等的上升,同时缓解干旱胁迫下光合速率、蒸腾速率、叶片相对含水量、叶绿素含量等的下降。[结论]通过喷施一定浓度的多效唑可以提高蓝莓的抗旱性。     

营养面积和行株距配置对红香芋植株光合特性及产量品质的影响

以地方品种‘建昌红香芋’为材料,设置6个植株配置组合,研究其对植株生长、冠层特征、光合参数及球茎产量品质等指标的影响,以探讨营养面积和行株距配置对芋植株光合特性及产量品质的影响。结果表明,单株营养面积越小,芋植株株高越高,叶片开展度越低。在营养面积为0.165m2和0.220m2的条件下,宽窄行为(70+40)cm的植株冠层光合有效辐射透过率显著高于宽窄行为(80+30)cm的植株,而光合有效辐射截获率则相反。株距为30cm的芋植株叶面积指数和冠层光合有效辐射截获率最大,冠层光合有效辐射透过率最小,植株的净光合速率(Pn)最低,其单株球茎产量最低,品质最差。株距为35cm时,芋植株具有较高的Pn,形成的单位面积球茎产量最高,品质最好。说明,合理的营养面积和行株距配置可有效调控芋植株冠层形态结构和光合有效辐射(PAR),影响光合作用,并最终影响球茎产量和品质。     

几种杀虫剂对小麦旗叶光合及叶绿素荧光特性的影响

为给小麦优质高效安全生产中科学使用杀虫剂提供理论和技术依据,以弱筋小麦扬麦13、强筋小麦烟农19为材料,在开花末期分别喷施推荐、3倍、6倍剂量的阿维菌素、毒死蜱、吡虫啉、乐果4种杀虫剂,研究其对小麦旗叶光合及叶绿素荧光特性的影响.结果表明,杀虫剂处理会改变小麦旗叶的SPAD值、光合速率及叶绿素荧光特性,且剂量越高影响越明显;不同类型杀虫剂对小麦光合速率及荧光特性的影响程度不同,影响较大的杀虫剂是吡虫啉和乐果,其次是毒死蜱,最后是阿维菌素;不同小麦品种对杀虫剂的耐受性不同,弱筋小麦扬麦13比强筋小麦烟农19的耐受性强.杀虫剂处理主要是通过降低叶片叶绿素含量、光系统Ⅱ的实际光化学效率(ΦPSⅡ)和光化学荧光淬灭系教(qP),引起单叶光合速率下降,最终导致小麦产量降低.     

花期干旱胁迫后限源疏库对玉米光合性能和茎流的影响

开展玉米花期干旱限源疏库试验,探索减轻花期干旱胁迫的技术途径。结果表明,去根叶组叶片可显著减少植株前期茎流,抑制叶片蒸腾,对穗5叶的叶绿素相对含量、光系统Ⅱ最大光化学效率(Fv/Fm)和潜在活性(Fv/Fo)影响不显著,正常灌溉情况下还有利于延缓玉米花后穗5叶的衰老,并促进后期茎流超补偿;去耕作层1/4根系会加剧前期植株水分的散失,干旱时浅中耕的措施是不可取的,并抑制后期茎流,增大Fv/Fm;去穗虽然可以显著减少茎流,抑制叶片蒸腾,但是因缺少库需求而加速花后穗5叶的叶绿素相对含量、Fv/Fm和Fv/Fo下降,促使叶片衰老。品种间对花期干旱胁迫后不同的限源疏库处理表现出显著差异,这是生物节水和作物补偿生长的生理基础。     

甜柿不同类型树体叶片光合、光照的研究

以成年新次郎树为试材,进行了甜柿树体的光合、光照研究。结果表明,丰产稳产树较低产树和变产树在光合、光照方面有以下特点:树冠叶幕外层叶面积较大;叶幕中层光照状况较好;叶幕中层叶片净光合速率较高,在所有测定时期整株净光合速率均较高。     

低磷胁迫下玉米幼苗生理响应及相关基因表达研究

以玉米品种合344为试验材料,对低磷胁迫下玉米幼苗叶片生理表型指标与玉米叶片转录组差异基因表达数据联合分析,探究低磷胁迫下与玉米幼苗叶片生理表型变化相关的关键响应基因及其调控规律.结果表明,低磷胁迫下玉米叶片的叶绿素荧光参数(FV/FM)以及叶绿素含量均有不同程度的降低,并且叶绿素合成相关基因大部分为下调表达,叶绿素降...     

等渗Ca和NaCl胁迫对黄瓜叶片叶绿体超微结构及光合特性的影响

采用营养液栽培,以盐敏感型的黄瓜品种津春2号为试材,研究了等渗Ca和NaCl胁迫对黄瓜幼苗叶绿体超微结构、叶片叶绿素含量、光合特性和叶绿素荧光参数的影响。结果表明：两种盐胁迫均降低了黄瓜叶片叶绿素含量,且NaCl胁迫后下降的幅度大于Ca胁迫。Ca胁迫后,叶绿体大部分与细胞壁脱离,基粒片层数减少|等渗的NaCl胁迫后,叶绿体结构变形,基粒片层膨胀、松散,片层之间界限模糊,嗜饿颗粒明显增多。Ca胁迫后净光合速率（Pn）、气孔导度（Gs）、PSⅡ最大潜在光化学效率（Fv/Fm）、PSⅡ实际光化学效率（ΦPSⅡ）和光化学淬灭系数（qP）下降的幅度均小于NaCl胁迫。Ca胁迫下植株的胞间CO2浓度（Ci）呈下降趋势,而NaCl胁迫下Ci呈上升趋势。综上所述,Ca胁迫主要通过气孔限制引起Pn下降|而NaCl胁迫严重破坏了叶绿体超微结构,主要通过非气孔因素限制引起Pn下降。