爬树蕨的解剖学研究

本文对爬树蕨（Ａｒｔｈｒｏｐｔｅｒｉｓｏｂｌｉｔｅｒａｔａ（Ｒ．Ｂｒ．）Ｊ．Ｓｍ）孢子体各主要器官进行了解剖学研究及对孢子进行了电子显微镜扫描观察,研究结果表明;茎的中柱具有两个新月形的维管束;幼茎的中部有髓．在较老的茎,髓部及中柱周围的细胞均特化为厚壁细胞．根属二原型中柱．木质分化方式是外始式;在对正后生木质部的两侧的皮层有几层特化为厚壁细胞。叶的叶肉细胞不分化出栅栏组织和海绵组织,为等面对。孢子囊具有纵向环带,孢子的形状、外壁的纹饰和裂缝情况均与以前的研究有所不同。     

凤尾蕨属5种植物孢子体形态研究

采用光学显微镜对凤尾蕨属5种植物孢子体形态特征进行观察和分析,以探讨该属植物的形态和亲缘关系,为凤尾蕨属的系统分类提供新的资料和依据.结果显示,该属5种植物的基本气孔类型为腋下细胞型和极细胞型;叶脉类型为无网眼的羽状分离型;副叶脉呈一回分叉平行分布;5种植物的维管束木质部多为单柱型管状中柱,也有部分双柱型网状中柱,管状分子中均有导管分子存在,仅在蜈蚣蕨和银脉凤尾蕨中发现管胞,其中井栏边草无纹孔膜残余.研究表明,蜈蚣蕨和银脉凤尾蕨较为原始,井栏边草、溪边凤尾蕨、紫轴凤尾蕨关系更近,也更为进化.     

瘤足蕨属(Plagiogyria)植物叶柄和羽片横切面解剖学特征及分类学意义

该文采用光学显微镜,首次对九种瘤足蕨属植物的叶柄和羽片横切面进行了解剖学比较研究。结果表明:九种瘤足蕨属植物在叶柄中部横切面的表皮、基本组织和中柱以及营养叶羽片的表皮、叶肉和主脉等结构特征是相似的,如叶柄中部横切面的表皮不被毛或是鳞片,表皮细胞形状呈类圆形,具有厚壁组织,中柱为周韧型维管束;营养叶羽片横切面的气孔只分布于下表皮,表皮细胞形状呈扁平状,主脉的结构类型属于周韧型维管束。在系统的演化中,瘤足蕨与桫椤科植物有一定的亲缘关系,两者既有相似的特征但也表现出一定的差异,支持瘤足蕨属是一个自然分类的观点。九种瘤足蕨属植物叶柄中部横切面形状有梯形、椭圆形和三角形,叶柄中部横切面维管束的形状成"U"字形、"V"字形或"品"字形;维管束数目1个或3个;维管束结构中的木质部成"八"字形、"U"字形或"一"字形;羽片主脉下侧形成了以三角形、弧形或梯形的突起;叶柄中的木质部形态有两种,即典型的海马形状以及非典型的海马形状,其中典型的海马形状的特点为叶柄的木质部两侧都呈现弯曲成钩的形态,非典型的海马形状特点为2个木质部束的两侧都未出现弯曲成钩的形态或者是其中的一个木质部一端无弯曲成钩的形态,这些形态解剖特征稳定且具类群特异性,为瘤足蕨属植物的分类和系统学研究提供了新的依据。同时,依据其叶柄和羽片横切面解剖叶柄学特征列出了瘤足蕨属植物分种检索表。     

山东产蹄盖蕨科2属植物形态解剖学的研究

采用光镜和扫描电镜对山东分布的蹄盖蕨科2属(蹄盖蕨属和假蹄盖蕨属)7种植物的根、根茎、叶柄、叶轴、叶表皮、表皮毛和孢子囊进行了形态解剖学的系统研究.结果表明,在形态解剖学方面2属植物的共同特征为:根均为无髓中柱;叶柄基部的双柱型维管束向上渐靠近联合形成1个周韧型维管束;叶上下表皮垂周壁均呈波状;气孔主要为胞环型、周胞型或极附型.2属植物的不同特征是:蹄盖蕨属植物体无毛;而假蹄盖蕨属植物叶片和叶轴上均生有腺毛;蹄盖蕨属植物根皮层外侧为薄壁细胞,假蹄盖蕨属则为棕色厚壁细胞环.研究结果表明蹄盖蕨科为一个自然分类群,并支持假蹄盖蕨属的成立.     

无距虾脊兰营养器官解剖结构及其生态适应性

采用石蜡切片法对无距虾脊兰（Calanthe tsoongiana T.Tang et F.T.Wang）营养器官解剖结构进行研究。结果显示,无距虾脊兰叶为等面叶,与一般植物相比,表皮毛和气孔器较少,均分布在下表皮,气孔器稍外凸,叶片维管束分化程度不一,木质部厚度远大于韧皮部。假鳞茎由表皮、基本组织和维管束组成,基本组织发达,含有丰富的内含物。维管束散生于基本组织中;根主要由根被、皮层和中柱组成,根被通常可见4层,皮层由8~10层薄壁细胞组成,菌丝体通过破坏根被细胞侵入皮层。除正对木质部脊的中柱鞘细胞外,其余中柱鞘通道细胞全面增厚,维管束类型为辐射维管束,中柱中央为薄壁细胞组成的髓。无距虾脊兰营养器官的解剖特征表现出阴生植物的特点,引种栽培过程中应注意适当遮荫和通风。     

无距虾脊兰营养器官解剖结构及其生态适应性

采用石蜡切片法对无距虾脊兰(Calanthe tsoongiana T.TangetF.T.Wang)营养器官解剖结构进行研究。结果显示,无距虾脊兰叶为等面叶,与一般植物相比,表皮毛和气孔器较少,均分布在下表皮,气孔器稍外凸,叶片维管束分化程度不一,木质部厚度远大于韧皮部。假鳞茎由表皮、基本组织和维管束组成,基本组织发达,含有丰富的内含物。维管束散生于基本组织中;根主要由根被、皮层和中柱组成,根被通常可见4层,皮层由8~10层薄壁细胞组成,菌丝体通过破坏根被细胞侵入皮层。除正对木质部脊的中柱鞘细胞外,其余中柱鞘通道细胞全面增厚,维管束类型为辐射维管束,中柱中央为薄壁细胞组成的髓。无距虾脊兰营养器官的解剖特征表现出阴生植物的特点,引种栽培过程中应注意适当遮荫和通风。     

稀子蕨胞芽发育及营养器官的形态与解剖学研究

该研究采用形态观察法、石蜡切片法以及扫描电子显微镜法对稀子蕨(Monachosorum henryi)胞芽发育过程及营养器官进行观察分析,以揭示不同蕨类植物胞芽生殖在发育生物学上的异同,为进一步探讨蕨类植物胞芽发育与被子植物珠芽发育的异同等奠定基础。结果表明：(1)稀子蕨羽叶薄,由7~8层细胞组成,气孔分布于下表皮,无明显栅栏组织和海绵组织分化。(2)稀子蕨的叶轴含1束“心”形维管束,叶柄基部至中部含2束维管束;成熟根能看到明显的维管束组织,无髓。(3)稀子蕨的复羽叶发育过程可分为萌动期、卷拳期、展叶期、成熟期和衰老期;复羽叶上的胞芽发育从展叶期开始,包括胞芽原基发育期、胞芽分化期、胞芽膨大期和胞芽成熟期。(4)稀子蕨胞芽原基起源于叶轴与羽叶分叉处表皮细胞下的薄壁细胞层;胞芽原基分化出多个叶原基,整体呈指状“锚”状;胞芽成熟后掉落土壤或在母体上萌发生长出新叶。     

广西爬树蕨属两种植物的细胞分类学研究

首次报道了中国广西产两种爬树蕨属植物的染色体数目及繁殖方式。爬树蕨和桂南爬树蕨的染色体数目都是n=40,2n=80(2x); 每个孢子囊的孢子数为64,是有性生殖二倍体。结合已有资料对爬树蕨属中的系统位置进行了讨论。     

莲幼苗初生维管系统研究

莲（Ｎｅｌｕｍｂｏ ｎｕｃｉｆｅｒａ Ｇａｅｒｔｎ．）幼苗属无根型。子叶片下部愈合呈筒状,并和子叶节区及其下部愈合为一体。子叶节区下部维管柱为χ形单中柱;子叶节区中部为周韧单中柱,子叶迹呈６束辐射均匀地进入子叶;子叶节区上部为散生中柱,其央的４－６个大维管束由子叶节区中部的单中柱分裂形成;周围的小维管束一部分由子叶迹分裂形成,一部分由周围薄壁细胞脱分化形成。     

两种铁角蕨的孢子体形态研究及水分生理测定

以铁角蕨属(Asplenium)两种不同植物的孢子体为材料(石生铁角蕨和变异铁角蕨),通过常规形态解剖方法和水分生理指标测定,分析探讨了这两种植物的形态特征与水分生理特点之间的适应性。结果表明:(1)石生铁角蕨和变异铁角蕨相比较,石生铁角蕨叶面积指数较大,叶片更为饱满。(2)两种铁角蕨表皮细胞的垂周壁均为不规则形,分别呈现出深波状或浅波状。(3)两种铁角蕨的气孔器全为下生气孔,且气孔器类型、形状、气孔大小及长宽比都很稳定。但是,二者之间气孔密度有很大差异,而气孔器类型以不规则四细胞型、腋下细胞型和极细胞型为主。(4)木质部维管束均为椭圆形的双柱型管状中柱,中柱内含有管状分子,呈背对月牙形分布,中柱大小约为80μm。(5)维管束内的管状分子次生壁出现不同程度的木质化增厚,以网纹、梯纹、孔纹的形式表现出来,管状分子的直径都较小,变异铁角蕨的木质部管状分子比石生铁角蕨的稍大。(6)石生铁角蕨的自然含水量较低,相对含水量较自然含水量变化较小,束缚水与自由水比值和水势较高。从石生铁角蕨和变异铁角蕨的叶表皮形态、气孔器特征、管状中柱和管状分子特征来看,将二者划分在同一属下是比较合理的。两种植物自然生境不同,其水分生理特征差异明显,但均与各自的形态特征相适应;石生铁角蕨的抗旱性比变异铁角蕨更强。该研究结果可为铁角蕨属植物的系统分类和抗旱性研究提供更多的资料。     

A NEW STRUCTURALLY PRESERVED PENNSYLVANIAN CORDAITEAN POLLEN ORGAN

Permineralized specimens of the pollen organ Gothania (Hirmer) consist of a primary axis bearing pollen cones in the axils of bracts that are four ranked. The bilaterally symmetrical primary axis consists of a uniform parenchymatous pith surrounded by up to 15 endarch-mesarch axile bundles. The cortex is two-parted and consists of an inner zone of subepidermal fibers. Bract traces arise from the ends of the ellipsoid stele. Traces to the cones are derived from the open ends of the stele, and at higher levels form a centrarch-medullated vascular system. Each pollen cone is constructed of up to 25 helically arranged scales, each vascularized by a single trace that may dichotomize. Scales are elongate and broad, and histologically composed of mesophyll parenchyma and fibrous layers. Stomata are restricted to the adaxial surface between rows of fibers. Up to 10 distal scales may be fertile, each with 4 elongate pollen sacs at the tip. Large monosaccate grains of the Felixipollenites-type are densely packed in each pollen sac. The well-preserved specimens of Gothania provide an opportunity to compare this genus with pollen cones assigned to the genus Cordaianthus, and to relate isolated plant organs to the Cordaitales.     

洞庭湖四种优势湿地植物茎、叶通气组织的比较研究

对通气组织的解剖观察有助于了解湿地植物的生长、分布及对不同生境的适应。采用石蜡切片技术,在光学显微镜下对洞庭湖湿地沿水位高程梯度分布的4种优势植物——荻Miscanthus sacchariflorus、水蓼Polygonum hydropiper、红穗苔草Carex argyi、虉草Phalaris arundinacea的茎和叶解剖结构进行了比较研究。结果表明：茎通气组织的形成部位主要在皮层、维管束和髓腔,其中髓腔所占比例最大（〉77%）。茎通气组织大小为：水蓼（57.8%）〉红穗苔草（45.5%）≥虉草（41.7%）≥荻（37.8%）。4种湿地植物的叶均在叶肉组织和（或）维管束内形成通气组织,如荻、虉草的形成部位是维管束,水蓼的是叶肉组织,而红穗苔草在叶肉组织和维管束内均可以形成,但以叶肉组织中为主,占99%。红穗苔草叶通气组织最发达,为33.8%,其它3种植物相对不发达,仅为0.13%～1.68%。除虉草外,其它3种植物通气组织大小与其分布位置具有很好的一致性。可见,湿地植物通气组织与其分布有较好的相关性。     

ONTOGENY OF THE PRIMARY THICKENING MERISTEM IN SEEDLINGS OF BOUGAINVILLEA SPECTABILIS

Anomalous secondary thickening occurs in the main axis of Bougainvillea spectabilis as a result of a primary thickening meristem which differentiates in pericycle. The primary thickening meristem first appears in the base of the primary root about 6 days after germination and differentiates acropetally as the root elongates. It begins differentiating from the base of the hypocotyl toward the shoot apex about 33 days after germination. The primary thickening meristem is first observable at the base of the first internode about 60 days after germination. It then becomes a cylinder in the main axis of the seedling. No stelar cambial cylinder forms in the primary root, hypocotyl, or stem because vascular cambium differentiation occurs neither in the pericycle opposite xylem points in the primary root nor in interfascicular parenchyma in the hypocotyl or stem. The primary vascular system of the stem appears anomalous because an inner and an outer ring of vascular bundles differentiate in the stele. Bundles of the inner ring anastomose in internodes, whereas those of the outer ring do not. Desmogen strands each of which is composed of phloem, xylem with both tracheids and vessels, and a desmogic cambium, differentiate from prodesmogen strands in conjunctive tissue. The parenchymatous cells surrounding desmogen strands then differentiate into elongated simple-pitted fibers and thick-walled fusiform cells that are about the same length as the primary thickening meristem initials.     

CAULINE VASCULATURE AND LEAF TRACE PRODUCTION IN MEDULLOSAN PTERIDOSPERMS

Medullosa and Sutcliffia specimens from the Paleozoic of North America and Europe are examined to determine the architecture of the cauline vasculature and mode of leaf trace production. Emphasis is placed on the identification and characterization of protoxylem strands and their relationship to leaf trace production. Organization of the primary xylem varies from a single protostele to a dissected stele composed of two to many more or less independent bundles. In Medullosa the bundles of primary xylem are each surrounded by secondary xylem, forming separate segments of vascular tissue (‘steles’ of previous workers). These vascular segments may divide and fuse at different levels in the stem. A definite number of protoxylem strands occur near the periphery of the primary xylem. The protoxylem strands divide at intervals producing protoxylem to the departing leaf traces. Leaf traces thus formed arise from all the vascular segments in a coordinated and predictable way and pass outward through emission areas in the secondary xylem. This type of cauline vascular architecture is compared to that of other seed plants. The vascular system of Medullosa stems is interpreted as a dissected monostele. Sympodial vascular architecture has apparently evolved from a protostele separately within the medullosan pteridosperms.     

波温苏铁(Bowenia spectabilis)营养器官的解剖结构研究

报道了波温苏铁Bowenia spectabilis Hook.ex Hook. f）根、茎、叶的解剖结构.根的初生结构由表皮、皮层和中柱三部分组成,为二原型木质部.茎具大量薄壁组织,薄壁细胞富含淀粉粒,维管束为外韧并生.叶柄中含有5-8束维管束,呈弧形排列.羽片叶角质层厚,有小叶脉产生,气孔主要分布在下表皮.根、茎、叶木质部中的管胞主要是螺纹和孔纹管胞,有少量纤维分化;茎中管胞的侧壁呈现凹凸不平,部分管胞具有分枝或分叉现象.     

Leaf anatomical characters and their value in understanding morphoclines in the Araceae

Leaf anatomy and petiole anatomy of the Araceae are discussed in terms of their potential use as character states in a phylogenetic analysis. The characters include leaf venation and structure, leaf epidermis, mesophyll ground tissue, vascular bundles, sclerenchyma, collenchyma, laticifers, secretory ducts, and raphide crystals. Characters that seem to have the greatest potential for use in phylogenetic analysis include those of ground tissue, vascular bundles, fibers, trichosclereids, collenchyma, and laticifers. Other, equally distinguishable, characters have states that are apparently autapomorphies, providing little phylogenetic signal. Therefore, although most leaf and petiole structural variation is useful diagnostically, some characters will probably be less valuable in phylogenetic analysis than originally hoped.     

STUDIES ON THE LEAF OF AMARANTHUS RETROFLEXUS (AMARANTHACEAE***): MORPHOLOGY AND ANATOMY

The leaf of Amaranthus retroflexus L. was examined with the light microscope to determine its vasculature and the spatial relationship of the vascular bundles to the mesophyll. Seven leaf traces enter the petiole at the node and form an arc that continues acropetally in the petiole as an anastomosing system of vascular bundles. Upon entering the lamina, the arc of bundles gradually closes and forms a ring of anastomosing bundles that constitutes the primary vein, or midvein, of the leaf. As the midvein progresses acropetally, branches of the bundles nearest the lamina diverge outward and continue as secondary veins toward the margin on either side of the lamina. Along its course the midvein undergoes a gradual reduction in number of bundles until only one remains as it approaches the leaf tip. Tertiary veins arise from the secondaries, and minor veins commonly arise from all orders of major veins, as well as from other minor veins. All of the major veins are associated with rib tissue, although the ends of the tertiaries may resemble minor veins, which are completely encircled by chlorenchymatic bundle sheaths and mesophyll cells that radiate out from the sheaths. A specialized minor vein, the fimbrial vein, occurs just inside the margin of the leaf. Most of the mesophyll cells—the so-called “Kranz mesophyll cells”—are in direct contact with the bundle sheaths, but some—the so-called “nonKranz mesophyll cells”—lack such contact. Non-Kranz mesophyll cells are especially prominent where they form a network of mostly horizontally oriented cells just above the lower epidermis. Guard cells of both the upper and lower epidermis are spatially associated with nonKranz mesophyll cells.     

虉草营养器官解剖结构与抗旱耐涝性及利用之间的关系

为了从显微结构上进一步探讨虉草(Phalaris arundinacea L.)的抗旱耐涝性及与利用的关系,于2011年采用常规石蜡切片技术,对其根、茎叶3种营养器官进行解剖观察。结果表明,虉草根的结构自外而内依次为表皮、皮层、维管束鞘、初生韧皮部和初生木质部;茎由表皮、基本组织和维管束构成;叶片内部结构可分为表皮、叶肉和叶脉3部分。根皮层大的细胞间隙和气腔,初生木质部的后生大导管和茎基本组织解体形成的髓腔都是虉草良好的通气组织,是其耐水淹的主要显微特征。茎、叶片角质化的表皮和叶表皮所含的丰富泡状细胞组是虉草具有抗旱性的主要解剖结构特征。叶肉细胞排列紧密且只有少量气孔分布于叶片下表皮,这样的结构可减少蒸腾;叶肉细胞富含叶绿体,增强光合作用,获得更多的同化产物,确保了植株在干旱条件下也有足够的光合产物来维持正常的生理活动。茎、叶维管束部分大量的木纤维起到支撑作用。虉草根的皮层和维管柱部分、茎的基本组织和维管束部分、叶的叶脉部分都含有大面积的厚壁细胞,厚壁细胞中含有丰富的粗纤维和木质素。丰富的粗纤维、木质素等成分则是虉草能成为新能源燃料植物的必备条件。