浙江杜鹃花属植物种子形态及其分类学意义

本文对浙江产杜鹃花属１３个种（录属５个亚属７个组）的种子形态进行了研究。比较观察了种子形状、大小、扁化率,翅和表面结构等形态学特征,井对该属种子形态的演化趋势、种于类型的划分及种子形态在分类学上的意义进行了讨论。结果表明种子形态特征与植物习性和形态特征一定程度上相关,反映了周内类群的分化,因而种子形态在杜鹃花属的系统研究中是不可忽视的性状。     

山东蔊菜属种子形态学研究及其系统分类学意义

对山东菜属植物的种子,从大小、翅、颜色和种子微形态等方面进行了研究;结果表明该属的种子为卵形或近圆形,呈扁平状;种子表面纹饰为网状或乳突状。与近缘属种子形态的研究表明,菜属和豆瓣菜属亲缘关系较近。因种子的形态特点比较稳定,所以菜属的种子特点可以为其分类、生药鉴定以及演化提供种子形态学方面的证据。     

山东Han菜属种子形态学研究及其系统分类学意义

对山东Han菜属植物的种子,从大小、翅、颜色和种子微形态等方面进行了研究;结果表明该属的种子为卵形或近圆形,呈扁平状;种子表面纹饰为网状或乳突状。与近缘属种子形态的研究表明,Han菜属和豆瓣菜属亲缘关系较近。因种子的形态特点比较稳定,所以Han菜属的种子特点可以为其分类、生药鉴定以及演化提供种子形态学方面的证据。     

iFlora中的种子形态学信息

植物种子形态特征的“多样性”和“保守性”在物种鉴别、分类和系统发育研究等方面具有重要价值。本文探讨了种子形态学信息在新一代植物志（或智能装置）iFlora中的应用,提出在iFlora中增加种子形态信息的必要性。种子形态特征不仅可作为iFlora中物种分类鉴定的重要参考性状．验证iFlora中分子鉴定和系统关系研究的结果,同时还能够进一步丰富iFlora中物种数据信息。     

青海省三种茄科植物种子微形态特征

运用扫描电镜对青藏高原地区3种茄科重要药用植物马尿泡(Przewalskia tangutica)、曼陀罗(Datura stramonium)和山莨菪(Anisodus tanguticus)18个自然居群的种子微形态进行了观察.种子的种皮纹饰在3个不同的物种之间具有显著的差异,可以分为4种类型.与山莨菪和马尿泡在植株、花、叶等形态差异较大不同,种子大小、颜色、形状及表面纹饰等在两个物种间非常相似,说明与曼陀罗属相比,山莨菪属和马尿泡属间可能具有较近的亲缘关系.结果说明种子微形态这一稳定的性状可以作为青藏高原茄科这3个属间的分类依据,具有重要的系统学意义,但是分类决策必须要包括形态学、细胞学、孢粉学、分子生物学等证据.     

烟草种子成熟变化及判定方法研究

通过科学地判断烟草种子成熟度,进而适时采收对于优质种质资源的保存、利用与开发以及提高种子品质与产量等在烟草实际生产中均具有重要意义。本文研究了烟草种子成熟过程中形态生理变化,包括种子形态变化(颜色)、种子内部生理指标变化(含水量、发芽指标)以及种皮叶绿素荧光指标变化规律;分析了这些指标在判断烟草种子成熟度的方面的应用,并进行了研究展望,提出了今后此类研究的方向及应该注意的问题。     

濒危植物缙云卫矛果实、种子形态分化研究

对缙云卫矛7个天然种群的果实、种子形态进行研究,测量果实和种子的数量、长度、宽度、重量等22项形态学指标。结果显示:果实、种子的形态性状在种群内和种群间均存在一定程度的变异,种群间变异系数平均值从0.750(种子数/序)到0.062(种子整体形态,长/宽),相比之下种子整体形态最为稳定。在种群水平上,果实、种子的形态性状有一定程度的分化,但不与种群间的地理距离远近相关联。形态分化与环境因子的灰色关联度分析表明,在所研究的环境因子中,没有发现一单一因子对其形态分化起绝对主导作用,不同环境因子对同一性状所起作用不同,且同一环境因子对不同性状的影响效应也有差异。潜在的主导因子是土壤中的全钾含量、土壤厚度以及土壤pH。     

山茱萸种子形态变异及与环境因子的相关性

山茱萸广泛分布于中国长江沿岸各省地区.由于土壤和气候的影响,分布区间山茱萸种子的形态变异较大.本文对4个省7个山茱萸群体的种子形态指标(种长、种宽、种子体积和种形系数)变异、种子形态指标间及与环境因子的相关性、种子形态地理变异趋势和群体聚类进行了探讨.研究表明:不同群体种子形态均存在显著差异;种子宽度与体积呈显著正相关,且二者与纬度呈显著负相关;种子宽度和种子体积的地理变异趋势明显;基于种子形态指标的聚类分析可将7个群体分为2个聚类群,北方群包括陕西佛坪、陕西汉中和河南栾川,南方群包括安徽宁国、安徽黄山、江苏镇江和安徽旌德.研究结果可为不同区域筛选优良山茱萸种源提供参考.     

金丝桃属9种植物种子形态及其系统学讨论

对金丝桃属5组9种植物的种子进行了宏观及微观形态学研究,以探讨岐山金丝桃的系统位置。结果显示,种子形态特征在本实验观察的5个组之间有明显差异。其中金丝桃组种子外形较为细长,种皮纹饰为狭长而规则的矩形网纹;黄海棠组种子稍粗,种皮纹饰为长宽近等的多边形(稀矩形)网纹;元宝草组的元宝草、贯叶连翘组的贯叶连翘以及挺茎遍地金组的云南小连翘种子均较小,元宝草种皮纹饰为负网纹,贯叶连翘种皮纹饰为相邻网纹间有间隙的近圆形网纹,云南小连翘种皮纹饰为复网纹。研究显示,岐山金丝桃的种子形态与黄海棠组最为接近,支持岐山金丝桃归于黄海棠组。     

国产广义飞蛾藤属(旋花科)植物种子表面微形态及其分类学意义

首次报道用扫描电镜观察的国产广义飞蛾藤局10种1变种植物的种子表面微形态特征。该属种子表面微形态特征可分为两大类型,其中I类型又可细分为3个亚型。除模式种Porana volubilis Burm.f.外,广义飞蛾藤属的种子表面微形态特征较为一致。因此,种子表面微形态特征不支持将广义飞蛾藤属拆分为4属或5属。研究结果显示,种子表面微形态在作为属内种的分类鉴别特征具有一定价值,如种子表面微形态支持保留毛果飞蛾藤的变种等级。将种子表面微形态与该广义属的花粉形态,以及宏观形态学特征进行对比分析,结果表明,广义飞蛾藤属种子表面微形态在属下等级的划分上没有很大价值。此外,鉴于P.volubilis Burm.I.具特殊的种子表面微形态特征,该种与广义飞蛾藤属属内其余种的关系值得进一步深入研究。     

Only seed size matters for germination in different populations of the dimorphic Tragopogon pratensis subsp. pratensis (Asteraceae)

Many studies have focused on the ecology of seed dimorphism, the production of two seed types by a single plant. Morphology and seed size are usually correlated, but how morphology affects germination percentage and seedling growth is poorly understood. Here we explicitly separate these effects for nine populations of the dimorphic species Tragopogon pratensis subsp. pratensis. Larger seeds yielded higher germination percentages, yet seed morphology had no additional direct effect on germination. Neither seed size nor seed morphology affected seedling growth. Neither germination nor seedling growth varied among populations, but seed head varied significantly. Results show that germination is mainly controlled by seed size rather than by seed morphology. This study is one of the few to distinguish explicitly between seed size and seed morphology effects on ecological characteristics and suggests that seed dimorphism may exert its ecological effects predominantly through its correlated size.     

Scanning electron microscopy of the seed coat in the genus Paulovunia (Scrophulariaceae)

A comparative study of the microscopic structures of external features of mature seeds of eight Paulownia species is presented. The external surface of the seed is made up of reticulate, apparently translucent cells, which laterally extend into wing-like structures. The laterally symmetrical wings are unequally extended in the micropylar and chalazal regions. The seed-coat ornamentation has a dorsiventral nature. Some special features of seed-coat morphology amongst the eight Paulownia species are discussed.     

Multiple pleurograms in Chamaecrista Moench (Leguminosae, Caesalpinioideae)

According to the literature, the seeds of Chamaecrista lack pleurograms and have pitted testas aligned in vertical lines. Preliminary observations have revealed that these small structures consist of superficial alterations of the testa that are coloured differently to the rest of the seed coat and stand out as pits. However, no anatomical inspection has yet determined the precise composition of these pits. The present work examined the morphology, surface micromorphology, anatomy, and histochemistry of the seed coat of mature seeds of C. desvauxii var. latistipula , C. flexuosa , and C. nictitans var. patellaria in order to elucidate the structural nature of the seed coat pits. For this, seed coats were studied using scanning electron microscopy and light microscopy. Structural modifications were examined in the seed coats of the studied species, and variations were noted in the mucilaginous layer, in the thickness of the palisade layer, and in the presence of larger hypodermic cells. Based on the anatomical features observed, and comparing these with published data on pleurograms in the Caesalpinioideae, it was determined that the structures referred to previously as tegumental pits on Chamaecrista seeds are actually small and numerous pleurograms, reported here for the first time.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 157 , 487–492.     

THE SYSTEMATIC SIGNIFICANCE OF SEED MORPHOLOGY IN THE NEOTROPICAL CAPSULAR-FRUITED MELASTOMATACEAE

Seed shape has traditionally been used as a tribal character in the capsular-fruited Melastomataceae. The seed morphology of the five neotropical tribes—Microlicieae, Tibouchineae, Rhexieae, Merianieae, and Bertolonieae—was studied with scanning electron and light microscopes. On the basis of seed morphology, five seed types are recognized: microlicioid, tibouchinoid, rhexioid, merianioid, and bertolonioid. Each of these types is illustrated and discussed, with some observations on the range of variation found. The genera of these five neotropical tribes were surveyed for seed morphology, and the results are presented here, together with a discussion of their systematic significance. On the whole, seed morphology confirms the existence of five tribes among the neotropical capsular-fruited Melastomataceae and provides interesting evidence for generic relationships; however, it also calls into doubt the taxonomic disposition of certain genera and the delimitation of these five tribes. The seeds of most genera fit into one of these five basic types, but there are some which do not; these exceptions are discussed in terms of their seed morphology and possible relationships.     

Seed Morphology of Impatiens L. (Balsaminaceae) and Its Taxonomic Significance

The seed surface of 12 species of Impatiens L. from Mt. Omei was observed under SEM for the first time. The important characters used in the paper include cell specialization on seed surface, arrangement pattern of the cells, the degree of the cell elevation, chalazal zone morphology and appendix at the tail of the seed. According to these characters, the seed surface morphology of 12 species can be divided into two types: 1. the seed without conspicuous differentiation of surface cells, laevigate on the surface, represented by I. wilsoni; the seeds of species indicated by 3-colpate pollen grains are expected to belong to the type. 2. the seed with the large cell elevation at different levels, surface scabrous, represented by the other 11 species; most species with 4-colpate pollen have this kind of seeds. The results verify that the seed morphology of the genus can supply characters significant to taxonomy of the genus at species level. The evolution of seed surface of Impatiens has close correlation with that ofthe flower and pollen morphology.     

A Triassic seed with an angiosperm‐like wind dispersal mechanism

The earliest record of a seed with a pappus‐like, parachute seed dispersal mechanism, Edenia villisperma gen. et sp. nov., is described from the Upper Triassic of the eastern United States. The seed is small and roughly triangular. Clusters of long hairs emerge from a whorl of at least five circular scars just below the proximal end. This morphology indicates that the hair clusters represent modified lateral structures similar to the pappus of several eudicot angiosperm groups, but probably representing a case of convergent evolution of a similar structure in a gymnosperm. The seeds are usually found isolated, but one specimen indicates that they were born tightly packed together on an axis. A few earlier records exist of dispersal hairs, but this is the first clearly indicating a pappus‐like structure. Although the exact affinities of Edenia are uncertain, this seed demonstrates that plants with highly advanced wind dispersal mechanisms occurred at least 55 million years earlier than previously thought.     

中国东北牻牛儿苗科(Geraniaceae)种子形态特征及其分类学意义

本文对中国东北牛儿苗科(Geraniaceae)二属(太阳花属Erodium, 老鹳草属(Geranium)计14种(species)1变种(Variety)和1变型(form)植物的种皮亚显微结构(SEM)及种子形态进行了研究.结果表明, 太阳花属与老鹳草属植物无论从种子形状, 长宽比, 还是种皮初级雕纹及次级雕纹形态都表现出明显差异。在老鹤草属下种及种下等级的鉴定和划分上, 种皮微形态及种子形态特征提供了大量有价值的信息。     

Population ecology of halophyte seeds

Some aspects of the population biology of halophytes are considered in this review. Persistent seed banks have been reported for a number of inland- and coastal-salt marsh plant communities. Seeds of perennial grasses are often under-represented, while annuals and some perennial forbs may be over-represented in the seed bank. The persistent seed bank of annual halophytes appears adaptive, and provides multiple seed germination opportunities which may prevent local extinction when environmental stress increases. Somatic seed polymorphism provides a mechanism by which parent plants can respond to changing environments by partitioning their resources into reproductive units which have distinct germination responses. Parental effects may influence either seed morphology and/or physiological requirements of seeds when they are exposed to environmental stress. A prolonged germination period can provide plant populations with numerous opportunities to establish seedling cohorts. Early cohorts will have a selective advantage under moderate conditions because mortality will be low and plants will survive until maturity. However, fluctuations in salinity levels and tidal activity can cause high mortality in early cohorts in salt marsh habitats, providing later cohorts with an opportunity for establishment. Resource allocation to reproductive structures is related to plant size, which itself can be affected by both abiotic and biotic factors. Larger plants were found to produce more seeds than smaller plants in a population, but the mean seed weight was greater in small plants.     

Cones structure and seed traits of four species of large‐seeded pines: Adaptation to animal‐mediated dispersal

Seed dispersal selection pressures may cause morphological differences in cone structure and seed traits of large‐seeded pine trees. We investigated the cone, seed, and scale traits of four species of animal‐dispersed pine trees to explore the adaptations of morphological structures to different dispersers. The four focal pines analyzed in this study were Chinese white pine (Pinus armandi), Korean pine (P. koraiensis), Siberian dwarf pine (P. pumila), and Dabieshan white pine (P. dabeshanensis). There are significant differences in the traits of the cones and seeds of these four animal‐dispersed pines. The scales of Korean pine and Siberian dwarf pine are somewhat opened after cone maturity, the seeds are closely combined with scales, and the seed coat and scales are thick. The cones of Chinese white pine and Dabieshan white pine are open after ripening, the seeds fall easily from the cones, and the seed coat and seed scales are relatively thin. The results showed that the cone structure of Chinese white pine is similar to that of Dabieshan white pine, whereas Korean pine and Siberian dwarf pine are significantly different from the other two pines and vary significantly from each other. This suggests that species with similar seed dispersal strategies exhibit similar morphological adaptions. Accordingly, we predicted three possible seed dispersal paradigms for animal‐dispersed pines: the first, as represented by Chinese white pine and Dabieshan white pine, relies upon small forest rodents for seed dispersal; the second, represented by Korean pine, relies primarily on birds and squirrels to disperse the seeds; and the third, represented by Siberian dwarf pine, relies primarily on birds for seed dispersal. Our study highlights the significance of animal seed dispersal in shaping cone morphology, and our predictions provide a theoretical framework for research investigating the coevolution of large‐seeded pines and their seed dispersers.