中国木犀属花粉形态研究及其系统学意义

观察了中国木犀属4组21种植物的花粉形态。花粉为圆球形或近长球形,外壁表面均具网状纹饰。大多数种类都具有三孔沟的萌发孔,极少四孔沟,或六萌发孔。内孔明显或不明显,有9种植物同时存在具三孔沟和具三沟二种类型的花粉及中间过渡类型(显脉木犀同时存在具三拟孔沟和具四拟孔沟)。很多特点表明,木犀属花粉的萌发孔在木犀科中处于由简单萌发孔向复合萌发孔过渡的阶段。根据网眼从沟间区中央到沟边是否变细,可将本属花粉分为两大类型,与分组有一定的对应关系。综合一些花粉特征,可发现本属花粉形态差异较明显,与一般形态差异有一定的相关性。花粉形态在木犀属具有一定的系统学意义。     

中国贝母属花粉形态的研究

本文对分布于我国的贝母属(Fritillaria L.)27种(变种)植物的花粉形态进行了光学显微镜和扫描电镜的观察,并对本属植物花粉的形态结构、类型、演化关系以及在分类学上的意义进行了讨论。     

中国西北地区萱草属花粉形态研究

本文借助光学显微镜和扫描电镜,对我国西北地区萱草属6种1变种的花粉形态进行了比较研究,不同的种类,其花粉形态或多或少有所不同,说明花粉形态在种间具有分类意义,而且6种、1变种可自然地分为两大类群,第一类群包括小黄花菜、北萱草、黄花菜,第二类群包括北黄花菜、折叶萱草、萱草、重瓣萱草。#br#北黄花菜、小黄花菜的花粉形态差别较大,证明把小黄花菜做为北黄花菜的变种是不妥当的。     

中国沙参属花粉形态的研究

对分布于我国的沙参属３２种（亚种,变种）植物的花粉形态进行了光学显微镜和扫描电镜的观察,研究结果表明：（１）沙参属植物花粉形态较相似,但其外壁纹饰,厚度,小刺密度,萌发孔情况在种,亚种,变种鉴别上有一定的意义。（２）本属花粉粒演化趋势为：表面条网状,条脊窄,小刺多,网孔类圆形→表面条状,脑纹状,条脊宽,小刺少,网孔不规则形。（３）花粉形态结合植物形态和染色体演化趋势,推断本属各组的演化关系为：基生     

中国苏铁属花粉形态研究

对中国苏铁属花粉进行了光镜和扫描电镜观察。花粉中等大,极轴长２６．５－３５．７μｍ,赤道轴长２０．６－２６．４μｍ;极面观椭圆形至近圆形,赤道面观船形或肾形,具远极单沟,达两端,其开闭和形状随花粉干燥或潮湿而变化,内部具多种不规则突起,两端具皱纹;远极面外壁光滑或稀具微突起,近极面具穿孔,孔穴或蜂窝状纹饰。     

中国钩藤属9种植物的花粉形态

利用光学显微镜和扫描电镜对中国钩藤属(Uncaria Schreb)9种植物的花粉形态进行了观察.结果表明,钩藤属植物的花粉为单粒,小型,辐射对称,赤道面观圆球形至近长球形,极面观3-裂圆形,具3孔沟,萌发沟裂缝状,长达两极.萌发沟中央有"内壁加厚突出"结构.外壁具条纹至细网纹饰,表面光滑无附属物.钩藤属花粉大小、形状、萌发沟和纹饰类型都较接近,属于单一型花粉.钩藤属植物的花粉形态特征是茜草科(Rubiaceae)中较为原始的类型.     

八角属花粉形态研究

本文利用光学显微镜和扫描电镜对八角属(Illicium L.)14种1变种的花粉形态作了研究。通过花粉形态的研究,验证了在分类上本属所分各组的合理性,讨论了该属花粉形态的演化趋势。     

中国鸢尾属花粉形态研究

本文借助光学显微镜和扫描电镜,对我国产鸢尾属Iris L．32种植物的花粉形态进行 了观察。该属植物的花粉为舟形或近球形。萌发孔可分为远极单沟、远极单沟-拟沟、二合 沟及无萌发孔等类型。外壁主要为网状纹饰,少数具瘤状或鼓槌状纹饰。本文依据花粉形态 和其它器官特征,对本属花粉外壁及萌发孔的演化趋势及某些种的分类地位进行了探讨。     

螺序草属(茜草科)的花粉形态

首次对螺序草属(Spiradiclis B1.)的11种和1变型共16份植物的花粉样品在光镜和电镜下进行了观察。结果表明,本属植物花粉为单粒,小型和中型花粉,近球形至椭球形,辐射对称,常具3孔沟,偶为4孔沟,外壁表面纹饰为孔状。花粉外壁由不连续的具穿孔的覆盖层、柱状结构和基层组成,内外壁明显。此外,本属植物的花粉具有花粉2型和“芽状”结构的现象。螺序草属植物的花粉形态在属下分类上有一定的局限性,但是在个体的系统发育上却可以提供极有价值的信息,如具有花粉单型的种类比花粉二型的种类进化。     

国产省藤属植物的花粉形态学

对国产棕榈科省藤属(Calamius L.)15种植物的花粉进行了光学和扫描电镜观察,其中12种为首次报道。省藤属的花粉均为两沟型花粉,外壁覆盖层多为网状纹饰(大喙省藤C．macrorrhynchus)或具穿孔(华南省藤C.rhabdocladus)。首次发现省藤属花粉的外壁纹饰存在穿孔和外壁疣状突起的类型(阔叶鸡藤C.pulchellus)以及皱波状突起的类型(长鞭省藤C.flagellum)。花粉的大小、形状、外壁纹饰、外壁是否有突起,外壁厚度和网状纹饰网眼的大小,对于省藤属的种级分类有较大的意义。     

Pollen of African Spermacoce species (Rubiaceae) Morphology and evolutionary aspects

Pollen morphology of 43 African species of the genus Spermacoce has been investigated by scanning electron and light microscopy. The genus is eurypalynous, which is reflected in the remarkable variation of almost all pollen characters. The average equatorial diameter (E) ranges from 15.8 w m to 115.5 w m. Grains are colporate or pororate. The number of apertures varies from 3 up to more than 25. The majority of species has apertures situated only at the equator (being zonoaperturate), but a few species have pantoaperturate grains. The endoaperture is generally an endocingulum, often with a secondary lolongate or lalongate thinning at the ectocolpus; endocolpi and endopores are also observed. The sexine is usually perforate, but eutectate, foveolate, and (micro)reticulate tecta were also found. Supratectal elements are present as granules, microspines or spines. The inner nexine surface is granular, often with irregular grooves (endocracks). Among native African species, nine pollen types are recognized mainly on the basis of pollen size, aperture morphology and tectum peculiarities. In two of the pantoaperturate types, apertures are in a configuration not yet recorded for the angiosperms in general. Some evolutionary trends are proposed that await verification by further systematic study. Pollen morphological characters have a high taxonomic value in the genus Spermacoce . They provide almost unique identification marks for the species, which enables sharpening of species boundaries. Small groups of related species often share the same pollen type. The genus Borreria , previously separated from Spermacoce on the basis of its fruit morphology only, is not supported by pollen data.     

Pollen Morphology of Quercus L. in China

The present paper describes the pollen morphology of 31 species of the genus Quercus from China. The pollen grains were all examined with light microscope and scanning electron microscope, and those of some species under transmission electron microscope. Pollen grains of the genus are spheroidal or subspheroidal, 16.8-50.4μm in diameter, 3colporoidate or 3-colpate. The exine is 2-layered, 0.4-1.8μm thick, sexine thicker than nexine, granulated tuberculate or verrucate.     

Application of DNA barcodes in Hedyotis L.(Spermacoceae, Rubiaceae)

The potential application of DNA barcodes of plastid (matK, trnH-psbA, petD, and rbcL) and nuclear (internal transcribed spacer (ITS) of rDNA) DNA regions was investigated for 25 Hedyotis taxa. The ITS showed the best species discrimination by resolving 23 of the species as exclusive lineages with no shared alleles between any of the 24 distinct species (H. Assimilis and H. Mellii are not supported as distinct species based on our molecular and morphological data). Conversely, rbcL performed the worst and only resolved 10 of the species as exclusive lineages, and 10 species with shared alleles. Using ITS has the advantage of high PCR amplification success and it provides good intra- and interspecific variation distribution patterns. The most powerful plastid markers were petD and trnH-psbA, but we could amplify and sequence trnH-psbA for only 83% of the accessions sampled. Combination of ITS and petD performed extremely well, with all 24 of the distinct species resolved as exclusive lineages and no shared alleles between any of the distinct species. We therefore recommend ITS, or a combination of ITS and petD, as the standard DNA barcode in Hedyotis, but acknowledge that there are no shared alleles between distinct species for marK and rbcL combined.     

峨眉山鸡矢藤属（茜草科）二新种

描述了四川峨眉山（茜草科）鸡矢藤属二新种,即峨眉鸡矢藤与长冠鸡矢藤。     

广义飞蛾藤属(旋花科)花粉形态

对广义飞蛾藤属Porana s.l.18个分类群的花粉进行了光学显微镜和扫描电镜观察。除前人报道过的7种1变种外,其余均为首次报道。根据花粉粒的大小、形状、外壁纹饰、沟膜特征,该属花粉可细分为4个类型。研究结果不支持Staples(1993)把该属分为4个独立属的观点,而认为在属内划分为4个亚属较为合理。除毛果飞蛾藤外,花粉形态支持Staples对其它种、变种的归并。从花粉萌发孔类型上看,广义飞蛾藤属在旋花科内应处于较为原始的位置。     

里普草属—中国茜草科一新纪录属

里普草属——Leptunis Stev。一年生草本植物。茎细弱,常茎中部分枝,枝细线状,圆柱形,无毛。叶轮生,全缘,无托叶,线状。花两性,辐射对称,花冠管状;无花萼;雄蕊4枚;子房二室;柱头二裂,柱头裂片球形;果为小坚果,常双生。     

Materials for Chinese Psychotria Linn.(Rubiaceae)

Two new species and one new combination of the genus Psychotria Linn.from China are described and made , They are P.fluviatilis Chun, P.densa W.C.Chen and P.rubra (Lour.) Poir.var.pilosa (Pitard) W. C. Chen