矢母根的组织发育及其与生长环境的关系

观察知母根的组织发育,发现具有典型的单子叶植物根的组织特征,特别是在同一条根中初生木质部脊数可以随机的发育而增加,同一株知母不同根之间初生木质部脊数也不尽相同;内皮层细胞壁增厚由凯氏带发育淡马蹄形,内皮层外侧１－３层皮层细胞内侧壁可以木栓化或强烈木化增厚。     

栽培太子参块根的发育解剖学研究

应用石蜡制片技术研究了栽培太子参纺锤状块根的发育过程。结果表明,栽培太子参的块根是由其不定根发育而成。太子参不定根的初生结构与次生结构的发育可分为4个阶段:原分生组织阶段、初生分生组织阶段、初生结构与次生结构阶段,类似一般草本双子叶植物根的发育。其特点是初生结构的皮层细胞大,仅3 ~4层,内皮层细胞具凯氏带;初生木质部多为三原型,少数为二原型、四原型与五原型。次生结构中次生木质部约占根面积80 %,主要为薄壁组织细胞,导管呈稀疏的放射状分布其中。由不定根发育成块根过程中,根据从根头至根尾不同距离的各组成部分的面积及细胞层数分析,从上向下其维管形成层活动强度不同,从而根的直径大小不同,使根发育成上粗下细的纺锤状肉质块根。高碘酸-Schiff反应显示,在成熟的块根中次生韧皮部的薄壁组织细胞和次生木质部射线间的木薄壁组织细胞内富含淀粉粒,在有些木薄壁组织细胞中还含有草酸钙簇晶。     

金粟兰属植物根的组织发育研究

观察金粟兰属7种、4变种植物不定根的组织发育,发现本属大多数植物不定根具有典型的单子叶植物不定根的组织特征,特别是在同一条根中初生木质部的脊数可以随根的发育而增加。双子叶植物和单子叶植物根的组织学系统发育不仅在本属大多数种内不定根的个体发育中得以重演,而且在属内种间得以重演。     

黄连体内黄连素的组织器官定位和根尖屏障结构特征研究

黄连(Coptis chinensis)是毛茛科著名药材,该文研究了黄连体内黄连素在组织器官中的分布规律和根尖屏障结构特征。在白光和荧光显微镜下,组织器官中黄连素在蓝色激发光下自发黄色荧光,黄连素-苯胺兰对染研究细胞壁凯氏带和木质化,苏丹7B染色栓质层,间苯三酚-盐酸染色木质化。结果表明:黄连不定根初生结构为维管柱、内皮层、皮层、外皮层和表皮组成;次生结构以次生木质部为主、次生韧皮部和木栓层组成。黄连根茎初生结构由角质层,皮层和维管柱组成;次生结构由木栓层、皮层和维管柱组成,以皮层和维管柱为主。叶柄结构为髓、含维管束的厚壁组织层、皮层和角质层。黄连不定根的屏障结构初生结构时期由栓质化和木质化的内皮层、外皮层;次生结构时期为木栓层组成;根状茎的为角质层和木栓层。黄连素主要沉积分布在不定根和茎的木质部,叶柄的厚壁组织层,木质部和厚壁组织是鉴别黄连品质的重要部位。黄连根尖外皮层及早发育,同时初生木质部有黄连素沉积结合,可能造成水和矿质吸收和运输的阻碍,也是黄连适应阴生环境的重要原因。     

白鲜根的发育解剖学研究

应用半薄切片、常规石蜡切片并结合离析法,对药用植物白鲜(Dictamnus dasycarpus Turcz.)根的发生发育过程进行了研究。结果表明:白鲜根的发生发育过程包括4个阶段,即原分生组织阶段、初生分生组织阶段、初生结构阶段以及次生结构阶段。原分生组织位于根冠内侧及初生分生组织之间,衍生细胞分化为初生分生组织。初生分生组织由原表皮、基本分生组织以及中柱原组成。原表皮分化为表皮,基本分生组织分化为皮层,中柱原分化为维管柱,共同组成根的初生结构;在初生结构中,部分表皮细胞外壁向外延伸形成根毛,皮层中分布有油细胞,内皮层有凯氏带,初生木质部为二原型或偶见三原型,外始式;根初生结构有髓或无。次生结构来源于原形成层起源的维管形成层的活动以及中柱鞘起源的木栓形成层的活动;白鲜次生韧皮部宽广,其中多年生根中可占根横切面积的85%,另外除基本组成分子外,还分布有油细胞;周皮发达,木栓层厚;初生皮层、次生木质部和次生韧皮部薄壁细胞中常充满丰富的淀粉粒。     

植物内皮层的发育与功能

在植物根的内皮层(某些茎的初生构造中也有)是皮层的最内层细胞。在结构和功能上,内皮层既不同于其内方的中柱鞘,也不同于外方的皮层薄壁组织。它的分化有着特殊的生理意义。植物组织发育的研究表明,内皮层来源于基本分生组织。但是,不同类群的植物,其内皮层的发育状况也不同。根中的内皮层常较为典型,它的发育一般终止于三种状态。第一种状态常见于大多数双子叶植物的幼根中,在幼小的内皮层细胞的径向壁和上、下端壁上,有一条初     

植物对硅的吸收转运机制研究进展

硅(Si)能缓解生物与非生物胁迫对植物的毒害作用,Si的吸收转运是由Si转运蛋白介导的.最近,多个Si转运蛋白(Lsi)基因相继在水稻、大麦和玉米中被克隆出来,并在Si的吸收转运机制方面取得了很大进展.水稻OsLsi在根组织中呈极性分布,OsLsi1定位在根外皮层和内皮层凯氏带细胞外侧质膜,负责将外部溶液中的单硅酸转运到皮层细胞内.OsLsi2定位在凯氏带细胞内侧质膜,在外皮层中负责将Si输出到通气组织质外体中,在内皮层与OsLsi1协同作用将Si转运到中柱中.导管中的Si通过蒸腾流转运到地上部,再由定位在叶鞘和叶片木质部薄壁细胞靠近导管一侧的OsLsi6负责木质部Si的卸载和分配.在大麦和玉米中,ZmLsi1/HvLsi1定位在根表皮和皮层细胞外侧质膜负责Si的吸收,然后Si通过共质体途径被转运到内皮层凯氏带细胞中,再由ZmLsi2/HvLsi2输出转运到中柱中.ZmLsi6在细胞中的定位和活性与OsLsi6相似,推测其可能具有类似的功能,但大麦Lsi6至今未见报道.所以,Si转运机制仍需要进一步研究.     

银州柴胡根的发育解剖学研究

本研究采用常规石蜡切片结合荧光显微镜技术对银州柴胡根的发育解剖学进行了研究。结果表明:（1）银州柴胡根顶端分生组织由原分生组织及其衍生的初生分生组织组成。原生分生组织细胞体积小、排列紧密、细胞质浓厚、细胞核大而明显，具有典型的分生组织的特点；（2）初生分生组织由根冠原、表皮原、皮层原和中柱原组成。在根发育过程中，表皮、皮层和维管柱共同组成其初生结构。银州柴胡根初生木质部为二原型或三原型，外始式；同时在根表皮细胞的径向壁观察到径向壁的细胞壁加厚；（3）在根次生生长过程中，位于初生木质部和初生韧皮部之间的原形成层恢复分裂能力产生维管形成层，维管形成层不断地向外产生次生韧皮部，向内产生次生木质部；同时位于根内皮层内方的中柱鞘细胞恢复分裂能力产生木栓形成层，木栓形成层向外形成木栓层，向内形成栓内层。在维管形成层和木栓形成层分裂的过程中，在次生韧皮部和中柱鞘组织中产生形态大小不同的分泌道，均为次生的裂生型分泌道。研究认为，银州柴胡根的结构类似于药典收录的北柴胡和红柴胡根的结构特点，但其根表皮细胞径向壁加厚、木纤维的分布、分泌道的大小和数量等有别于柴胡属其它植物，可作为柴胡属植物重要的分类鉴定依据。     

碱蒿营养器官的扫描电镜观察研究

用扫描电子显微镜对碱蒿（Artemisia anethifolia）营养器官的解剖学特征进行了观察与研究。结果表明：碱蒿属于典型的泌盐盐生植物。叶肉质化,表皮上气孔为无规则型气孔,密集下陷,有较多的盐囊泡和分杈腺毛分布,表皮细胞外壁加厚,外壁的外层角质化,为等面叶,栅栏组织细胞排列疏松,叶中央为发达的储水组织,木质部有多束维管束;茎表皮上有少许气孔,并分布有腺毛和众多盐囊泡,表皮细胞外壁加厚形成角质层,皮层宽度较小,皮层薄壁组织细胞内可见淀粉粒,中柱后生木质部为口径大的导管,原生木质部为口径小的导管,管内充满盐晶体,中间有发达的贮水薄壁细胞;根的表皮细胞排列疏松,外皮层细胞排列紧密而整齐,中部皮层薄壁细胞层数较多,细胞中贮藏有许多淀粉粒,内皮层细胞排列紧密,初生木质部导管发达,内部周围存在大量盐晶体,根的次生木质部有通气组织。这些解剖结构均表现出碱蒿具有适应盐碱、干旱生境的结构特征。     

黄芩根的解剖学研究

用常规石蜡切片方法对黄芩(Scutellaria baicalensis Georgi)一、二年生主根的发育及结构进行解剖学研究.结果表明,黄芩根的发育可分为原分生组织、初生分生组织、初生结构和次生生长等4个阶段.原分生组织由3 群原始细胞组成,其细胞具有典型分生组织的细胞学特征;初生分生组织包括根冠原、表皮原、皮层原和中柱原,其中根冠原和表皮原具有相同的起源.初生结构由表皮、皮层和中柱组成.初生木质部为二原型.次生生长主要是由维管形成层和木栓形成层的活动完成,木栓形成层起源于中柱鞘细胞.二年生黄芩主根的主要结构与一年生的基本相同,其不同之处为:二年生主根的周皮增厚,次生木质部中木纤维成群分布,出现木间木栓;维管射线为多列且明显;在近周皮的韧皮部内出现包围石细胞的木栓环组织.     

ADVENTITIOUS ROOT DEVELOPMENT FROM THE SEEDLING HYPOCOTYL OF LYCOPERSICON ESCULENTUM

Tomato seedlings five through ten days old were used for this investigation. Adventitious roots were initiated from the pericycle of the tomato hypocotyl. The position of adventitious root development was irregular in the rhizogenic hypocotyl; however, the cellular pattern of individual root development was very regular. Four layers of pericycle derivatives participated in root histogenesis and a bi- or triseriate endodermal cover was derived from the endodermis. Fluorescent microscopy showed that Casparian strips on the meristematic endodermal cell walls were not removed biochemically but were displaced around the root primordium by anticlinal divisions and cell enlargement. Casparian strips were not synthesized by endodermal cover cells. The emergent root had a typical three tiered or closed pattern of apical organization, and quiescent centers were present in all emergent roots longer than 0.5–0.6 cm.     

GROWTH STUDIES OF THE ROOT OF INCENSE CEDAR,LIBOCEDRUS DECURRENS. I. THE ORIGIN AND DEVELOPMENT OF PRIMARY TISSUES

Wilcox , Hugh . (State U. Coll. of Forestry, Syracuse, New York.) Growth studies of the root of incense cedar, Libocedrus decurrens. I. The origin and development of primary tissues. Amer. Jour. Bot. 49(3): 221–236. Illus. 1962.—The anatomical features of active and dormant roots of incense-cedar seedlings are described and discussed in relation to various problems of differentiation and morphogenesis. Autoradiographs confirm the presence of a group of relatively inactive cells at the site of the apical initials. During periods of maximum growth activity, the presence of a quiescent center is accentuated by a peak in number of divisions in adjacent tissues. With diminution in growth activity, the peak occurs closer to the quiescent center and the size of the meristem appears to diminish. During dormancy, the configuration of the initial region seems to indicate the existence of apical initial cells which coincide with a minimal constructional center, as determined by studies of cell lineage. Roots whose apical cells retain their meristematic appearance are able to resume growth after a period of dormancy, whereas roots whose apical cells undergo vacuolation are likely to perish. Graphs are presented to show the functional relationships between growth rate and the varying distances from the apical meristem at which the tissues of the root differentiate and mature. Although early differentiation of precursory phloem could be discerned almost as soon as early vacuolation of metaxylem, its recognition was more dependent upon subjective judgment. The functional relationship between differentiation and growth rate was most pronounced in the maturation of protoxylem elements, the development of Casparian strips in the endodermis, the development of suberin lamellae in the endodermis, and by the development of phi layers in the inner cortex.     

THE ULTRASTRUCTURE OF THE STALK AND BASE OF THE ANTHERIDIUM OF POLYTRICHUM

The fluorescent boundary across the stalk of an antheridium of Polytrichum appears as a distinctive, secondary wall layer in electron micrographs. Lamellations of electron-dense and -lucent materials cause this layer to resemble the “suberized lamellae” of root endodermis and leaf bundle sheaths in grasses. The cells of the stalk below the boundary are especially rich in lipid droplets, whereas those in the base of the antheridium, above the boundary, have markedly fewer and smaller lipid droplets and abundant rough endoplasmic reticulum often in loosely parallel arrays. Cytological differences develop before the boundary appears, so that the distinctive wall layer is secreted by protoplasts that are already specialized morphologically. During maturation of an antheridium there is a secretion of a fluid into a space that forms at the bottom of the sperm chamber. However, the cells surrounding this fluid show no special morphological adaptations that would seem to relate to secretion.     

OBSERVATIONS ON THE ROOT ANATOMY OF RICE (ORYZA SATIVA L.)

Rice plants were grown hydroponically and roots were prepared for light and electron microscopy using standard techniques. The roots are bounded by an epidermis, exodermis, and fibrous layer. The exodermis has a suberin lamella along its inner tangential wall. The fibrous layer is composed of thick-walled lignified cells with little pitting. The cortical parenchyma is compact when young, but expands and separates to form a zone of cell walls and air spaces in a spoked arrangement. Supporting columns of living parenchyma cells are occasionally present, particularly near lateral roots. The endodermis is typical for grasses with Casparian strips, suberin lamellae, and tertiary state walls with numerous pits. The pericycle and pith become sclerified. Protoxylem elements alternate with protophloem in the young root; later, early metaxylem, late metaxylem, and metaphloem proliferate. The exodermis, fibrous layer, lacunate cortex, and endodermis appear to present a formidable barrier to radial ion movement in the mature portions of the root.     

THE ROOT APEX OF MALVA SYLVESTRIS. III. LATERAL ROOT DEVELOPMENT AND THE QUIESCENT CENTER

Both histological and autoradiographic procedures were used to follow lateral root initiation and development. Lateral roots of M. sylvestris were initiated in the pericycle, and although the endodermis became multiseriate, endodermal derivatives were not incorporated into the lateral root primordium. Apical organization of pre-emergent roots, characterized by two tiers of cortical initials, did not change with growth. During pre-emergent development there was no evidence of cortical lysogeny or quiescent center formation. Quiescent centers were present in both secondary and tertiary roots longer than 0.5 cm.     

结球甘兰下胚轴组织培养形态发生的组织学研究

结球甘兰离体下胚轴培养,近切口的中柱薄壁细胞首先启动分生,中柱外的内皮层,皮层,表皮细胞随后也启动分生。随着愈伤组织的生长和愈伤形成层的建成,维管组织与分生组织产生。组织培养中出现的多倍性细胞团和单倍性细胞,不会引起原二倍体物种的遗传性变异和性状变化。在愈伤组织中,芽多为外起源。由原体原始细胞和原套原始细胞发育成芽原基,进一步形成不定芽。另外,不定芽还可由外植体皮层内薄壁组织直接产生。不定根为内起     

加兰他敏在忽地笑营养器官中的定位(简报)

石蒜属植物为具有地下鳞茎的多年生草本植物．有重要的药用价值,全属植物约有20余种。我国有石蒜属植物约15种,集中分布于长江中下游地区,野生资源比较丰富。忽地笑（Lycorisaurea Herb．）是石蒜属植物在我国分布较广泛的一种。加兰他敏（Galanthamine）等生物碱是石蒜属植物中主要的药用成分。[第一段]     

红豆杉营养器官的解剖学研究

通过对红豆杉营养器官的解剖学研究,阐明其根、茎、叶的结构特征,为红豆杉的开发利用研究提供了解剖学依据。研究结果表明红豆杉营养器官具有以下特征：（1）根、茎、叶中均无树脂道;（2）根、茎皮层中均有含单宁类物质的细胞分布;（3）根、茎中均有石细胞分布,（4）叶气孔器为双环型,略内陷;（5）根为二原型,（6）幼根的内皮层具凯氏带加厚,中柱鞘细胞富含单宁类物质;（7）根的次生维管组织中射线发达。     

THE ROOT APICAL MERISTEM OF EQUISETUM DIFFUSUM: STRUCTURE AND DEVELOPMENT

The root apical meristem of Equisetum diffusum Don has a prominent four-sided pyramidal apical cell with its base (distal face) in contact with the root cap. Derivatives (merophytes) that contribute to the main body of the root are produced from the three proximal faces of the apical cell. The first division of a proximal merophyte is periclinal to the root surface separating a small inner cell from a larger outer cell. The inner cell is the precursor of the vascular cylinder. The larger outer cell is the precursor of the epidermis, cortex, endodermis, and pericycle. Radial sectors, established early in the development of the cortex, alternate with sectors in the vascular cylinder. These developmental steps show quite clearly that early root development in Equisetum is markedly different from that of most ferns.