中国植物花粉形态的研究进展

中国植物花粉形态研究经历了3个发展阶段;从1953年建立国内第一个孢粉学实验室到1960年我国第一部花粉形态学专著的出版为起步阶段;1961-1980年由于历史的原因,国内的研究发展较慢;80年代以来,中国植物花粉形态学研究进入了一个高速发展阶段。迄今已系统研究过花粉形态的在中国裸子植物中占63.64%。在双子叶植物中占36.36%,在单子叶植物中占33.33%。     

中国红树科7种红树植物遗传多样性分析

以红树、红海榄、秋茄、角果木、木榄、海莲、尖瓣海莲等7种红树科植物为材料,采用改进的CTAB法获得了纯度较高、得率高、片段完整的基因组DNA。通过筛选出的15个有效引物进行RAPD分析,探讨了7种树植物间的亲缘关系。15个有效引物共扩增出617条DNA带,其中多态性条带415条,占总扩增条带的67.26%。利用Nei指数法得出7个分类群间的遗传一致度和遗传距离,并运用UPGMA法进行聚类分析。7个分类群分为A、B两个大组,平均遗传距离为0.41。将得出的7个分类群的DNA分子分类系统图,与传统的分类进行比较,发现结果相符。同时获得一个OPG05－900的差异片段可作为区分海莲和尖瓣海莲的分子标记。     

大亚湾红树林研究Ⅱ,澳头港部分红树植物的生态生理

对大亚湾澳头港的３种红树植物的光合速率、呼吸速率和蒸腾速率进行测定,结果表明：桐花树、白骨壤和木榄的光合速率日进程呈双峰曲线,日平均光合速率的大小为桐花树＞木榄＞白骨壤,而日均呼吸速率的大小为桐花树＞白骨壤＞木榄,呼吸速率的变化幅度小于光合速率,提示白骨壤的生产力最低,可能与其所处的生境含盐量更高有关。蒸腾速率日进程呈单峰曲线,且泌盐植物桐花树和白骨壤的日均值很接近,都高于拒盐种木榄,表明蒸腾速率与它们的泌盐或拒盐生理特性密切相关。总体上,这些红树植物具有较高的光合速率、较低的呼吸速率和蒸腾速率,有利于生长在盐渍淹水的特殊海滩环境。     

我国药用红树植物

红树植物的药用价值逐渐被世界各地的科学家所认识,相关的研究也正在成为热点。其实,我国红树林生长地区的居民一直在用红树植物治疗一些疾病,红树药用资源也十分丰富,绝大多数药用红树植物在我国都能找到。比如前文提到的海漆、老鼠勒,此外还有角果木、银叶树等等。     

我国某些蜜源植物花粉形态研究

本文对我国一些蜜源植物花粉形态特征用光学显微镜作了各种数据测定,并对花粉形态进行了扫描摄片研究。对蜂花粉团成分也作了观察。本项研究为了蜜源花粉的开发和利用提供了有价值的资料。     

真红树植物和半红树植物叶片性状的比较研究

红树植物是一类生长在热带、亚热带海岸潮间带的乔木、灌木或草本植物,根据其分布特征可分为真红树植物植物和半红树植物.为了探究两者对海岸潮间带高盐、高光和缺氧等环境的生态适应策略的异同,该文选取5种真红树植物植物[卤蕨(Acrostichum aureum)、木榄(Bruguiera gymnorrhiza)、老鼠簕(Ac...     

中国东属植物花粉形态及其系统学意义

从系统学分类学的角度出发,对国产栎属31个种的花粉进行了光学显微镜和扫描电镜观察。研究结果表明栎属的花粉萌发孔对该属的系统与分类无太大的参考价值;但栎属的花粉纹饰有颗粒状,聚粒状两种主要类型,具有重要的系统学分类学价值。花粉形态的研究结果支持将栎属植物划分为常绿类与落叶类的观点,栎属巴东栎组植物的花粉纹饰在种间存在分化,花粉形态的研究结果支持将巴东栎组至少划分为两个不同类群的观点;在佐以其他证据的情况下,栎属植物的花粉纹饰还具有重要的分类学价值。     

红树(Rhizophora a piculata Bl.)的花粉形态与多态现象

通过光学显微镜(LM)和扫描电子显微镜(SEM)观察表明,红树(Rhizophora apiculata)花粉粒赤道面的形状为球形-近球形,极面观为圆三角形,偶见圆四方形,3-4孔沟,具有连续的环赤道内孔,花粉外壁的典型纹饰为细网状-皱纹状(microreticulate-rugulate)。作者首次报道红树花粉的多态现象,其花粉外壁纹饰和萌发孔数量存在显著的变异,SEM观察到花粉外壁纹饰的变异主要是孔状(perforate)、皱纹状(rugulate)和穴状(foveolate)等类型,LM观察发现4个萌发孔的花粉变异类型。花粉形态的观察与描述为化石花粉的鉴别提供了不可或缺的对比依据。研究红树的花粉形态和发现多态现象有助于了解红树科红树属的花粉外壁演化。花粉的多态现象表明单个花粉形态特征并不能完全代表种的特征。花粉的分类也应该充分考虑花粉性状的间断和连续性,以期正确认识花粉性状在种群内的变异和变异式样,达到客观认识和正确划分植物种下等级的目的。花粉的多态现象为化石花粉的种类鉴定增加了新的参考信息,作者也讨论了花粉多态现象在植物系统演化和古生态学等研究中的可能价值与意义。     

天南星属植物的花粉形态

利用扫描电镜对天南星科天南星属（Arisaema)8组25种植物的花粉进行研究（其中,12种前人未观察过,12种中11种为我国特有）。结果显示：本属花粉形态基本一致,即球形,无萌发孔,无覆盖层,具微刺,是一个非常自然的类群。但各个种在花粉粒大小,刺长,刺的形状,刺基部上径,刺的密度和刺间纹饰方面差别较大,可以作为区别种的依据。这进一步证实了前人的结论。花粉形态支持学者们关于天南星属是本科最进化的类群之一的观点。天南星属花粉可能由线花组从花粉大小适中、刺密度居中向大或小、密或疏的方向发展;刺间表面纹饰对探讨组间演化关系意义不大。Murata等对于花粉刺间具较密颗粒为曲序组特征的界定可疑;把A.yunnanense Buchet、A.bathycoleum Hand.-Mazt.和A.prazeri Hook.f.归入曲序组似乎不妥。A.consanguineum Schott和A.fraternum Schott的花粉形态没有支持李恒对这两个种的归并。     

水雍科植物的花粉形态研究

应用光学显微镜、扫描电镜和透射电镜对世界水雍科6种植物的花粉形态进行了观察。水雍科植物花粉为舟形或船形,具远极单沟萌发孔类型,外壁纹饰通常为浅网状至网状,稀为小刺状纹饰,外壁外层由覆盖层、柱状层和基层组成,覆盖层厚。水雍科植物花粉外壁纹饰表现了从小刺状向网状的过渡。该科花粉为远极单沟,覆盖层厚,具小刺等特征反映了其与水鳖科和泽泻目花蔺科的密切联系,而该科花粉外壁纹饰多为网状则与茨藻目植物接近。这一结果支持将水雍科从茨藻目中分出作为一个独立的目处理的观点。此外,水雍科植物的花粉大小、纹饰类型、网眼大小与深浅等方面的差异对种级分类有一定意义。     

人工红树林幼林藤壶危害及防治研究进展

随着近年来红树林恢复性造林面积的扩大,海洋污损生物藤壶对红树林幼林的危害问题日益突出.文中综述了藤壶附着的生物化学、藤壶在红树林附着的生态学、藤壶对人工红树林幼林的危害和国内所采用的化学药物防治措施等方面的研究进展,以及今后的研究方向.藤壶在红树林的附着和分布模式受海水盐度、浸淹深度、林分郁闭度、水文条件等环境因素和生物因素的影响.而藤壶胶粘蛋白的氨基酸组成、一维结构,胶粘蛋白在水下的交联、组装和胶粘的过程与机制,以及藤壶危害红树幼苗的机制和危害权重尚需要深入探讨.研究红树植物对藤壶附着的响应和长期适应机制将为藤壶的防治提供更多的启示.     

Late Holocene mangrove dynamics of Marajó Island in Amazonia,northern Brazil

Two sediment cores from the eastern coastal region of Marajó Island, Pará State, northern Brazil have been studied by pollen analysis to reconstruct late Holocene mangrove dynamics and environmental changes. Seven AMS radiocarbon dates provide time control. Mangrove vegetation became established at the Barra Velha site at about 2750 B.P. (2880 cal B.P.) and at the Praia do Pesqueiro site at about 650 B.P. (670 cal B.P.). Rhizophora was the dominant mangrove tree throughout the recorded period, while Avicennia and Laguncularia were rare. Existing remnants of the former coastal Amazon rain forest were replaced by mangrove in the Barra Velha area between about 2750 and 740 B.P. (2880–760 cal B.P.) and at Praia do Pesqueiro area between about 650 and 530 B.P. (670–540 cal B.P.), suggesting a rise in relative sea level or, alternatively, an increase in discharge from the river Amazon. Areas of coastal shrub and herb vegetation, the so-called restinga vegetation, also became slightly reduced during the late Holocene. The largest area of mangrove at the two sites suggests that the highest sea level was probably reached during the last 200–250 years. The only evidence of human activity at the two sites is an indication of cattle pastureland at the Barra Velha area during the last decades.     

Holocene mangrove dynamics and sea-level changes in northern Brazil, inferences from the Taperebal core in northeastern Pará State

A 450 cm sediment core from Taperebal, in the mangrove region of northeastern Pará State in northern Brazil has been studied through pollen analysis in order to reconstruct mangrove development and dynamics and to infer relative sea-level (RSL) changes during the Holocene. Six AMS radiocarbon dates, which provide a somewhat limited age control with some uncertainties, suggest early and late Holocene deposits interrupted by a hiatus between them. A patchy vegetation of coastal Amazon rain forest, restinga, salt marsh and some mangrove, which was dominated by Avicennia, covered the study area during the early Holocene period. The occurrence of an early Avicennia dominated mangrove phase has not been reported so far from other sites in northern Brazil. During the mid Holocene mangroves mostly replaced the former coastal Amazon rain forest, restinga and some salt marsh vegetation, reflecting the rise in the RSL. Rhizophora trees expanded markedly and Avicennia became rare. In the sediment core there is apparently a gap between the depths of 115 and 85 cm (possibly starting between 5900 and 5750 b.p.). The deposits above 85 cm are of modern age and were probably deposited during the last decades. This gap can be explained by the lowering of the RSL as is shown for other northern Brazilian coastal sites. The deposition of sediments during the last decades suggests that the modern RSL is high compared to other periods in the Holocene. Pollen data from these deposits show that Rhizophora trees dominate the mangrove forests, also indicating a high RSL.     

Holocene palynology and sea-level change in two estuaries in Southern Irian Jaya

Southern New Guinea leads the continental Australian plate into convergence to form the New Guinea Highlands. Extensive inter-tidal deltas are typical of much of this low gradient equatorial coastline. In two adjacent estuaries in Irian Jaya (West Papua), this study uses present elevations of mangrove species zones as a finite indicator of Holocene sea levels from pollen diagrams of estuarine cores. All cores showed mangroves at levels well below the present tidal range, with landward species zones being replaced over time by seaward zones. Results show tectonic subsidence in the recent period, with Late Holocene relative sea-level rise of 0.67 mm year⁻¹.     

Evaluating Swiss pollen productivity estimates using a simulation approach

We simulated pollen assemblages for 11 sites on the Swiss Plateau (Schweizer Mittelland) based on a low resolution land cover map and pollen productivity estimates (PPE) from this region. A comparison between observed and simulated pollen data demonstrated that the majority of the simulated pollen proportions were within a range of 5% of over- or underestimation, and that at eight of the 11 sites the dominant taxon was correctly estimated. The modelled sum of arboreal pollen was correct within ±11% at nine sites. Our results indicate that the PPE established for the Swiss Plateau can be used to simulate pollen assemblages with reasonable accuracy. Moreover, our results justify the use of the POLLSCAPE simulation using the Prentice-Sugita model and its variations of pollen dispersal and deposition in more complex topographic landscapes than those to which they have hitherto been applied.     

深圳福田白骨壤群落Cr,Ni,Mn的累积及分布

探讨了深圳福田自然保护区白骨壤红树林对Ｃｒ、Ｎｉ、Ｍｎ的吸收、累积及分布．结果表明,该林地土壤Ｃｒ、Ｎｉ、Ｍｎ含量从底层至表层逐步提高;表层（０～３０ｃｍ深）３种元素含量分别为７．９７、２５．０和５３７μｇ·ｇ－１,贮量分别为１０９９．８６、３４５０．００和７４１０６．００ｍｇ·ｍ－２．白骨壤植物各部位Ｃｒ、Ｎｉ、Ｍｎ含量范围分别为０．２８～０．７５、０．４３～７．６５和２５～１５５２μｇ·ｇ－１;植物对表层土壤加权平均富集系数为Ｍｎ＞Ｎｉ≈Ｃｒ．该群落Ｃｒ、Ｎｉ、Ｍｎ的现存累积量分别为６．０６、２０．７６和１６３１．１７ｍｇ·ｍ－２,年净存留累积量分别为０．４３、１．４３和１０７．９８ｍｇ·ｍ－２;林地残留物相应元素储量分别为Ｃｒ７８．００μｇ·ｍ－２、Ｎｉ１５３６．３３μｇ·ｍ－２和Ｍｎ４０５．５４ｍｇ·ｍ－２．该林区３种不同类型群落叶层Ｃｒ、Ｎｉ现存累积量为白骨壤林＞桐花树林＞秋茄林,Ｍｎ为秋茄林＞白骨壤林＞桐花树林．     

Seasonal distribution of airborne pollen in the coastal plain of Israel

Airborne pollen was monitored in three major urban centers of the coastal plain of Israel during the years 1993–1995. Results show spatial and temporal variations among the three sites. Altogether, the number of identified species was rather low. Ornamental trees (Cupressaceae,Pinus, Olea, Casuarina, Ceratonia) and grasses, have constituted the main source of the pollen rain. A substantial contribution of the wild plants of the region was restricted toParietaria, Urtica, Mercurialis, Artemisia, grasses and members of the Chenopodiaceae and Amaranthaceae.     

同一植物群落中基于光学显微镜荧光和亮场成像的花粉形态鉴定：以一个横断山脉高山草甸为例

花粉形态具有物种特异性,是花粉识别的关键属性。花粉的精确识别可为植物分类、物种演化、花粉传递网络等研究提供基础信息。本研究采集了滇西北香格里拉区域高山草甸群落36科92属135个植物物种的花粉,归纳总结了花粉的提取、测量和特征描述方法。首次利用光学显微镜荧光和亮场成像描述花粉的形态特征,并绘制了完备的花粉图像库。本研究使用多重因子分析对花粉形态特征进行了贡献值排序,建立了定距式花粉检索表。本文为区域群落传粉生态学等研究中基础花粉库的建立提供了参考。     

Development of mangrove habitats along ria shorelines in north and northwestern tropical Australia

Along ria shorelines mangrove assemblages are closely related to habitat types and there is a recurring pattern in their distribution that is linked to the origin and history of the geomorphic units. The coastal geomorphology is related to ancestral landforms developed prior to the post-glacial transgression, as well as to tidal levels, aspect, modern shore-forming processes, and types of hinterland/tidal flat contacts. These historical and process patterns develop distinct geomorphic units which dictate the distribution of habitats and their mangrove assemblages. Mangrove assemblages are classified according to their habitat: main tidal flat, hinterland fringe, alluvial fan, spit/chenier, tidal creek bank, tidal creek shoal and rocky shore. Within a given habitat there are various physico-chemical gradients which are instrumental in developing zonation within the assemblages. The variety of internal zones within an assemblage is related to the richness of species within the regional species pool which in turn is related to climate.