哈密瓜花粉离体萌发特性的研究

通过哈密瓜花粉在固体培养基上进行离体培养，对哈密瓜品种金皇后的离体萌发特性进行研究。结果表明，培养基中硼酸的不同浓度对哈密瓜花粉离体萌发具有明显的影响，适宜的硼酸浓度为20mg／L；在不同的温度条件下，哈密瓜花粉的萌发率不同，25℃时哈密瓜花粉的萌发率达到了最大值，花粉萌发的适宜温度范围为10．35℃，随着温度的升高，花粉管的长度也相应的增加；另外，不同的贮藏时间和贮藏温度对哈密瓜花粉的萌发率也有一定的影响，一般在低温条件下贮藏花粉，可以较长时间保持花粉较高的萌发率。     

十字花科植物花粉发育相关基因的研究

花粉发育是一个极其复杂的过程,众多基因参与其中,这些基因的行为控制着花粉发育的各个关键步骤,从而调控花粉发育的正常进行.从分析以拟南芥为代表的十字花科植物花粉发育基因的行为入手,介绍了十字花科植物花粉发育研究的最新进展,包括目前人们在花粉发育的起始、减数分裂、花粉有丝分裂、生殖细胞有丝分裂,以及绒毡层在花粉发育过程中的作用等方面的认识和理解.     

Pollen Morphology of Artemisia L. and Its Systematic Significance

The pollen of 57 species representing 7 sections of Artemisia was examined hy light microscope and scanning microscope for the purpose to elucidate the systematic relationships of the genus. The examination indicates that the pollen grains present high concordance which is characterized by the globular or the appruximate shape. 3-lobed circular from polar view while granular or ellipse sphere from tropical plate with tricolporate structure. The exinc of pollen has an obvious double structure of inner and outer layers (including the tecturn and columnar layers) where the outer is thicker than the inner and the sculpture of exine degenerates into small spinules easily distinguishable from other genera of the Compositae. Based on cxine sculpture, the pollen grains of Artemisia can be divided into two types: Myriantha type and Mongolica type, which possesses 4 subtypes according to the distribution forms of spinulc: (1) Sacrorum subtype, (2) Oligocarpa subtype, (3) Lavandulaefolia subtype. (4) Anomale subtype.     

从中国古植被记录看东亚季风的年龄

我国最近发现的早中新世季风记录，对东亚季风系统何时形成又提出了疑问．现代季风系统的一个明显特征，在于它打乱了行星气候系统纬向分布的带状模式，因而地质记录中季风气候地理模式的出现，就应当意味着季风系统的建立．据此汇总了中国大陆125个地点所获得的古植物和岩性资料，揭示了两种完全不同的气候分带模式：早第三纪宽阔的干旱带由西向东横跨中国大陆，而晚第三纪至今的干旱带仅局限在中国西北部．渐新世／中新世交界时气候系统的大改组，就是现代东亚季风建立的证据．其后，季风系统在晚第三纪又经历了巨大变化，包括15～13Ma前、8Ma、3Ma前干旱气候的加剧和季风系统的加强．所获得的新资料并不支持亚洲季风系统起源于约8Ma前这一观点，而认为东亚大约是在晚渐新世向季风气候转变这一假设更为合适．     

半夏绒毡层细胞降解的显微观察及花粉活力检测

本文对三叶半夏的变形绒毡层的降解过程进行了显微观察，发现绒毡层细胞随着花粉母细胞的减数分裂和小孢子发育的进行，其细胞位置、细胞壁和核的形态发生改变．Feulgen反应显示变化过程中细胞核内染色质结构是完整的，染色质与细胞结构随着花粉的成熟逐渐降解．FCR法检测，发现花粉活力在散落后逐渐降低．本文探讨了绒毡层与花粉活力的关系，以及半夏在自然情况下有性繁殖能力较低的原因．     

玉米花粉多糖中的单糖组成分析

单糖经α-萘胺衍生化以后，用硼砂做电泳介质，实现高效毛细管分离，得到标准的α-萘胺衍生单糖的毛细管区带电泳图谱．将不同分离纯度的玉米花粉多糖水解成单糖，用相同的方法衍生后电泳，得到多糖的毛细管电泳图谱．与标准谱图对照。得出多糖的组成成分．     

Deep-water Oligocene pollen record from South China Sea

Leg 184 of ODP recovered a record of deepwater sediments spanning the past 32.8 Ma from the South China Sea (SCS). The sediments of the Ofigocene (32.8-23.8 Ma) at Site 1148 contain relatively abundant fossil pollen. The pollen analysis at Site 1148 has established the first pollen assemblage sequence of deep-water Oligocene in the China Sea. The pollen assemblages of the Ofigocene are dominated by montane conifer tree pollen. The abundances of broad-leaved tree pollen are lower in the assemblages.Both of the montane conifer and broad-leaved tree pollen groups include mainly tropical-subtropical components. The pollen of cold and drought-enduring plants is present in lower content. The distinct change in pollen assemblage sequence of deep-water Oligocene of the SCS occurred at 32.0 Ma, indicative of an important shift of the Oligocene climate in the SCS region. The characteristics of the pollen flora of the deep-water Oligocene indicate the tropical montane ralnforest and lowland ralnforest developed on the areas around the SCS before 32.0 Ma, reflecting the warm and wet climatic condition. In the pollen flora of the Oligocene after 32.0 Ma, the temperate montane conifer and cool and drought-en- during deciduous tree taxa remarkably increased, indicating that the climate in the SCS region became comparatively cool and dry.     

几种常见观赏植物花粉的电镜观察

用扫描电镜对金盏菊等观赏植物的花粉进行了形态观察,探讨了不同科属植物花粉之间的关系.结果显示,菊科(金盏菊和绿串珠)花粉为近球形或扁球形,表面为脑网状纹饰,具刺状突起;芸香科(佛手、柚和金桔)花粉为长球形,表面具清晰的网状纹饰或穴状纹饰;木兰科(含笑和广玉兰)花粉为两侧对称,表面为拟网状或脑网状纹饰;百合科(百合和吊兰)花粉为两侧对称,表面为网状或穴状纹饰;蔷薇科(野蔷薇和月季)花粉为长球形,表面为条纹状或皱波状纹饰.表明不同科属植物的花粉大小、形状、表面纹饰不同,可作为植物学分类的依据.     

Pollen evidence of early human activities in Erhai basin, Yunnan Province

The evidence of human activities around Erhai Lake catchment was revealed by pollen records from a sediment core in the lake, northwest Yunnan Province. The chronologic sequence based on AMS ^14C data made it possible for pollen results to compare with archaeological records and historical documents. The preliminary deforestation started from the selective clearance at about 5500 ^14C a BP, marked by the loss of vertically distributed montane forest and the expansion of second pine woodland across the catchment. The deforestation resulted in the increase of surface runoff and the enhanced erosion in the catchment. The increased herbs of pasture and crop suggested the primitive agriculture and stockbreeding in study region. With the limited human activity, as well as the suitable climatic condition, second pine forest expanded quickly, resulting in the weakened soil erosion around the basin. The strong forest clearance inferred from pollen occurred since 2160 ^14C a BP, paralleling to the first dense immigration of population, when Yeyu County was first set up around west coast of Erhai Lake, documented in historic record. The development of agriculture led to the steady enhancement of soil erosion from farming land, increasing the input of fine materials and nutrients to the lake. Moreover, the serious deforestation by human activity stressed the vulnerability in ecosystem of the landscape. The time of primary anthropologic impact recorded from pollen is earlier than that of the oldest archaeological record by 1500 a (^14C year).     

松属花粉形态研究及其分类学意义

本文报道了松属7种植物花粉形态的光学显微镜和扫描电子显微镜的研究结果,并分析了该属花粉的亚显微形态特征.各种花粉粒从远极面观呈近圆形、方形、椭圆形;近极而观呈椭圆形或近圆形.帽的表面纹饰为颗粒状或瘤状.花粉粒的体高×体长介干43.2μm×36.8μm～64.2μm×46.3μm之间.研究结果表明松属花粉的形态特征支持传统的属级和种级水平的分类.