【作者】 王强；

【导师】 金则新； 郭水良；

【作者基本信息】 上海师范大学 ， 植物学， 2013， 硕士

【摘要】 以国家2级保护植物长叶榧(Torreya jackii)为研究对象，对长叶榧及其伴生植物的光合特性、长叶榧不同营养器官黄酮类化合物和挥发油类化合物含量、不同居群长叶榧黄酮类化合物和挥发油类化合物含量进行测定与分析，比较不同季节不同生境中长叶榧叶片光合速率的大小，并分析环境因子对其光合作用和次生代谢产物的影响，从光合特性方面阐明长叶榧的濒危机理，同时通过对长叶榧次生代谢产物合成和积累规律的认识，有助于对红豆杉科植物长叶榧合理的开发和利用。1、利用Li-6400XT便携式光合作用仪对不同生境、不同季节长叶榧光合生理生态指标进行测定，探讨林窗、林缘、林下3种生境中长叶榧光合能力的季节变化及其对不同光环境的响应。结果表明：夏季，林窗、林缘的长叶榧净光合速率(Pn)日变化呈“双峰”曲线，其他季节均呈“单峰”曲线;林下的长叶榧Pn日变化在4个季节均呈“单峰”曲线。3种生境中最大净光合速率(Pnmax)、光饱和点(LSP)、表观量子效率(AQY)、最大羧化速率(Vcmax)、最大电子传递速率(Jmax)、磷酸丙糖利用率(TPU)均为夏季>秋季>春季>冬季，他们之间均差异显著；林窗、林缘的光补偿点(LCP)以夏季最高，林下以冬季最低；3种生境中的暗呼吸速率(Rd)均以夏季最高，和其他季节差异显著。四个季节中，长叶榧的Pnmax、LSP、TPU、Rd均以林窗最高，林缘次之，林下最低，Pnmax、LSP、TPU不同生境差异显著；Rd林窗、林缘和林下差异显著；春季、秋季和冬季Vcmax、Jmax也为林窗最高，林缘次之，林下最低，不同生境差异显著；夏季Vcmax、Jmax林缘最高，林窗次之，林下最低；其他季节均为林窗最高，林缘次之，林下最低，不同生境差异显著；4个季节中AQY为林下最高，林缘次之，林窗最低，林下与林窗、林缘差异显著。综上所述，长叶榧在4个季节中以夏季光合能力最强，3种生境下均以林窗的光合能力最强，长叶榧表现出阳性植物的特点，适宜生长于光线充足的环境。林窗环境下，长叶榧在春季、夏季Pnmax、LSP、AQY显著低于其伴生植物，秋季长叶榧的AQY也显著低于其常绿伴生种，冬季LSP也显著低于其常绿伴生植物。春季林窗长叶榧LCP显著低于其4种伴生植物，而在夏季LCP显著高于其4种伴生植物。春季林窗长叶榧Rd显著低于伴生种，而在夏季显著高于伴生种。春季和夏季林窗长叶榧Vcmax、Jmax、TPU均显著低于除薄叶润楠以外的伴生种，秋季、冬季也显著低于青冈栎。前3个季节长叶榧月均Pn与伴生种相比处于中下水平，并且由于夏季强光和高温的作用限制了长叶榧光合能力，Pn午间下降持续时间最长，光合能力低，在群落内种间竞争将处于不利地位。2、不同生境中叶绿素a、叶绿素a+b含量为夏季>秋季>春季>冬季，不同季节差异显著，叶绿素b含量夏季显著高于其他季节。春季、夏季、秋季不同生境的叶绿素a、叶绿素a+b含量均以林下最高，林缘次之，林窗最低，它们之间均差异显著，叶绿素b含量林下显著高于与林窗、林缘。冬季叶绿素a、叶绿素b、叶绿素a+b含量均为林窗最高，林缘次之，林下最低，它们之间差异显著。春季、夏季、秋季长叶榧及其伴生种叶片Fv/Fm日进程变化规律基本一致，呈“V”字型，早上较高，之后逐渐降低，在中午12:00时降到最低点，下午又能逐渐恢复到最初的水平。夏季林窗和林缘12:00时Fv/Fm显著低于林下。夏季林窗长叶榧在12:00时Fv/Fm显著低于其种伴生植物，表明在夏季高温和强光下长叶榧受到的胁迫要显著高于其伴生种。3、3种生境中，长叶榧叶片SOD酶活性和POD酶活性均以夏季>秋季>冬季>春季，不同季节差异显著；夏季SOD酶活性和POD酶活性均以林窗最高，林缘次之，林下最低，不同生境差异显著。春季长叶榧SOD酶活性显著低于除白栎以外的伴生种，秋季和冬季显著低于其伴生种。春季长叶榧POD酶活性显著低于其伴生种，夏季、秋季显著高于青冈栎和盐肤木，而冬季要显著高于青冈栎。不同季节长叶榧及其伴生植物叶片MDA含量均以夏季>冬季>秋季>春季，不同季节差异显著。春季、夏季不同生境中MDA含量均以林窗最高，林缘次之，林下最低，不同生境差异显著。长叶榧MDA含量在4个季节中均显著低于其伴生种。不同季节中长叶榧叶片膜透性以夏季>冬季>秋季>春季，不同季节差异显著，夏季、秋季膜透性以林窗最高，林缘次之，林下最低，夏季不同生境差异显著；春季长叶榧膜透性显著高于其伴生种，而在夏季显著低于其伴生种。4、采用微波辅助萃取从长叶榧不同营养器官中提取黄酮类化合物，最佳萃取条件为乙醇浓度90%、料液比1:40、萃取温度85℃、微波时间5min。结果表明：长叶榧各营养器官中均含有黄酮类化合物，以一年生叶中含量最高，其次为老叶，嫩枝中含量也较高，而老枝、树皮、根中含量较少。在4个季节中黄酮总量为林窗>林缘>林下，不同生境差异显著，一年生叶片和老叶中黄酮类化合物含量为夏季>秋季>春季>冬季，不同季节差异显著。采用超零界CO2萃取技术从长叶榧不同营养器官中萃取挥发油，最佳萃取条件为萃取压力16Mpa、萃取温度45℃、萃取时间5min。结果表明：长叶榧各营养器官中也均含有挥发油，以一年生叶中含量最高，其次为老叶，老枝、树皮，根中含量较少。4个季节中一年生叶片和老叶挥发油含量夏季>秋季>春季>冬季，不同季节差异显著，挥发油总量为林缘>林窗>林下，不同生境差异显著。利用HPLC对长叶榧不同营养器官黄酮类和生物碱类化合物进行成分分析，结果表明：黄酮类和生物碱种类均以叶片中最多，根中次之，树皮和老枝中种类较少。5、抑菌试验表明：长叶榧精油对细菌的抑菌属于低敏，对霉菌的抑菌效果属于中敏，而长叶榧乙醇提取物对细菌和霉菌的抑菌能力都属于中敏。长叶榧乙醇提取物具有较好的清除DPPH自由基、抗氧化能力，1g长叶榧叶片干粉相当于3.05mg维生素C清除DPPH自由基的能力。更多还原

【Abstract】 The photosynthetic physiological characteristics and the secondarymetabolites of Torreya jackii in family Taxaceae, an endangered species endemic toChina, was studied in order to better develop and utilze this resource. The photosyntheticcharacteristics of T. jackii and its accompanying plants, the content of the flavonoids andvolatile oil of Torreya jackii collected from different populations and those in thedifferent organs of T. jackii were tested. The photosynthetic rates of Torreya jackii indifferent habitats collected in different seasons were compared and the effect of theenvironmental factors on the photosynthesis and the sedonary metabolites were analyzed.The endangered mechanism of T. jackii was elucidated based on the photosyntheticcharacteirstics and the rules of the synthesis and accumulation of the secondarymetabolites were concluded in this study.1. We used a portable photosynthesis measuring system （Li-6400XT） to determinethe photosynthesis characteirstics of T. jackii in three natural light habitats （gap, edgeand understory）. The results show that the diurnal vairation of the photosynthetic rate ofT.jackii in forest gap and edge habitats in the summer are typical curves with doublepeaks, while those in the other seasons and those at understory habitat in all four seasonsare shown in curves with single peak. The net photosynthetic rate (P_nmax), light saturationpoint （LSP）, the apparent quantum yield （AQY）, maxmium rate of carboxy lation （Fcmax）,maxmium rate of electron transport （Jmax）, and triose phosphate utilization rate （TPU）significantly differ in four different seasons ranking in the order:summer>autumn>spring>winter. The light compensation points （LCP） of T. jackii in theforest gap and edge habitats are the highest in the summer, while those of Torreya jackiiunder the forest is the lowest in the winter. The dark respiration rate （Rd） in three different habitats are the highest in the summer, which is significantly different from theother three seasons.P_nmax, LSP and TPU of T. jackii in four seasons differ significantly in three differenthabitats, ranking in the order: forest gap>forest edge>underforest./?d differ signiifcantlyamong three different habitats. Fcmax and./max of T. jackii in spring, autum and winterdiffer signiifcantly in three different habitats with the order: forest gap〉forestedge>underforest, while the order in the summer is forest edge>forest gap>underforest.AQY in four seasons in three different habites ranked in the order: underforest>forestedge>forest gap and that in underforcst habitat is significantly higher than those in forestgap and edge habitats. In conclusion, the photosynthetic efficiency of T. jackii is thehighest in the summer and that of T. jackii in forest gap habitat. This suggests that T.jackii is a typical sunny plant based on the photosynthetic characteristics and growsbetter in the habitat with enough light.In the spring and summer, the尸nmax、LSP、AQY of T. jackii in forest gap aresignificantly lower than its acompanying plants, and the AQY of T. jackii in autumn issignificantly lower than its acompanying plants, and in winter, the LSP of T. jackii isalso significantly lower kythan its acompanying plants. The LCP and Rd of T. jackii inspring are significantly lower than four acompanying plants, but are signiifcantly higherthan the other four acompanying plants. Rd of T. jackii in spring is significantly lowerthat its accompanying plants，while that in summer is signficanlty higher than itsaccompanying plants. In spring and winter, the Fcmax、Jmax> TPU of T. jackii aresigniifcantly lower than its companying plants except Mach i I us leptophylla, and inautumn and winter, those are signiifcantly lower than Cyclobal anopsisglauca.Compared with the accompanying plants, the monthly Pn of T. jackii is under theaveraged level and the photosynthetic efficiency is low limited by the strong light andhigh temperature with the longest lasting period of the declination of midday Pn. Thissuggests that T, jackii takes adisadvantage place in the interspeciifc competition in thecommunity.2. The content of chlorophyll a. chlorophyll b and chlorophyll a+b of T. jackii indifferent habitats differ signiifcantly among four seasons, ranking in the order:summer>autum>spring>winter. The content of chlorophyll b in summer is significantly higher than the other three seasons. In spring, summer and autumn, the content ofchlorophyll a and chlorophyll a+b differ significantly in different habitats, ranking in theorder: underforest>forest edge〉gap，while the content of chlorophyll b of T. jackii in theunderforest habitat is significantly higher than that in the forest edge and forest gaphabitat. In winter, the content of chlorophyll a, chlorophyll b and chlorophyll a+b of T.jackii differ significantly in different habitats, raking in the order: gap>forestedge>underforest. In spring, summer and autumn, the diurnal variation curves of FJFmof T. jackii and its acompanying plants are typical “V” type, which is the highest in themorning，then decreases gradually and reaches the lowest at12:00. and returns graduallyto the initial level in the atfernoon. In summer, FJFm of T. jackii at12:00in the forestgap is signiifcantly lower than its acompanying plants, suggesting the effects of the hightemperature and strong light on T. jackii were higher than those its acompanying plants.3. The activities of peroxidase and superoxide dismutase differ significantly in thefour seasons, ranking in the order: summer>autumn> winter>spring. In summer, theactivity of peroxidase and superoxide dismutase different significantly in three habitats，ranking in the order: forest gap>forest edge>underforest. In spring, the activity ofsuperoxide dismutase of T. jackii is significantly lower than its acompanying plantsexcept for Quercus fabric. In autumn and winter, that is significantly lower than itsacompanying plants. In spring, the activity of peroxidase is significantly lower than itsacompanying plants, but in summer and autumn, that is signiifcantly higher thanCyclobalartopsis glauca and Rhus chinensis, while in winter, that is significantly higherthan Cyclobalartopsis glauca. Tthe malonydialdehvde content of T. jackii and itscompanying plants in three habitats differ significantly among four different seasons,raking in the order: summer>winter>autumn>spring. In spring and summer, the contentof malonydialdehyde differs significantly among different habitats, ranking in the order:forest gap>forest edge>understory. The malonydialdehvde content of T. jackii in fourdifferent seaons are significantly lower than those in its companying plants. Themembrane permeability of T. jackii differs signiifcantly among four seasons, ranking inthe order: summer〉winter>autumn>spring. In summer and autumn, the membranepermeability of T. jackii in the forest gap are the highest followed by the forest edge,while that in the understory habitat is the lowest. In summer，there are significant difference among three different habitats. In spring, the membrane permeability of T.jackii is significantly higher than its companying plants, but is significantly lower thanits companying plants in summer.4.Flavonoids was extracted from T. jackii using the microwave-assisted extractionmethod. The optimal condition is:90%ethanol, solid-liquid ratio1:40, irradiation°temperature85C and the irradiation time5min. Flavonoids were detected in allthevegetative organs of T‘jackii, with the highest in the annual leaves and the second inthe old leaves followed by the twigs. The flavonoids content in the old branches，barkesand roots were relatively low. The flavonoids content of T. jackii differed significantlyamong three different habitats, ranking in the order: gap>edge>understory. The contentof flavonoids in annual leaves and the old leaves differed significantly among fourdifferent seasons, ranking in the order: summer>autumn>spring>winter.The volatile oil of T. jackii was extracted using the supercritical carbon dioxideextracted method. The optimal condition is: extraction pressure16Mpa，extractiontemperature45°C, extraction time5min. The volatile oil were detected in allthevegetative organs of T, jackii，with the highest in the annual leaves followed by theold leaves, while that in the old branches, barkes and roots were relatively low. Thevolatile oil content in the annual leaveas and old leaves of T. jackii differed significantlyamong four different seasons, ranking in the order: summer>autum>spring>winter.The total content of volatile oil of T. jackii differed signiifcantly among three differenthabitats, ranking in the order: forest edge>forest gap>underforest. The composition ofthe flavonoids and alkaloid extracted from different organs of T. jackii were analyzedusing HPLC method. The number of the components in the flavonoids and alkaloids of T.jackii in the annual leaves and the old leaves were the most followed by those in theroots, while those in the old branches and barkes were the lowest.5.The bacteria are lowly sensitive to the volatile oil of T. jackii while the fungi aremoderately sensitive*The bacteria and fungi are moderately sensitive to the ethanolextract of T. jackii. The ethanol extract of T. jackii showed strong DPPH-free radicalsclearance effect and the antioxidant capacity.1gram dry powder of the extrac had theDPPH^free radicals clearance ability similar with3.05mg of ascorbic acid.更多还原