荸荠营养器官的发育与解剖学研究

荸荠同化茎起源于肉质主茎倒２或倒３叶的叶腋内。同化茎基部着生二鞘状叶,鞘状叶对早期同化茎穿出土面具保护作用。匍匐茎大多起源于同化茎基部鞘状叶的叶腋内。当植株开始抽生花茎时,地下匍匐茎顶端开始膨大。球茎的膨大是匍匐茎顶端５－６节的基本组织经细胞有丝分裂,增加细胞数目,然后由细胞体积的扩大来实现的。球茎具足够的营养物质供来年顶芽萌发的需要,故属水生植物冬芽的性质。     

THE ORGANIZATION OF THE VASCULAR SYSTEM IN THE STEMS OF THE NYMPHAEACEAE. II. NYMPHAEA SUBGENERA ANECPHYA,LOTOS, AND BRACHYCERAS

The anatomy and organization of the stem vascular system was analyzed in representative taxa of Nymphaea (subgenera Anecphya, Lotos, and Brachyceras). The stem vascular system consists of a series of concentric axial stem bundles from which traces to lateral organs depart. At the node each leaf is supplied with a median and two lateral leaf traces. At the same level a root trace supplies vascular tissue to adventitious roots borne on the leaf base. Flowers and vegetative buds occupy leaf sites in the genetic spiral and in the parastichies seen on the stem exterior. Certain leaves have flowers related to them spatially and by vascular association. Flowers (and similarly vegetative buds) are vascularized by a peduncle trace that arises from a peduncle fusion bundle located in the pith. The peduncle fusion bundle is formed by the fusion of vascular tissue derived from axial stem bundles that supply traces to certain leaves. The organization of the vascular system in the investigated taxa of Nymphaea is unique to angiosperms but similar to other subgenera of Nymphaea.     

THE ORGANIZATION OF THE VASCULAR SYSTEM IN THE STEMS OF THE NYMPHAEACEAE. III. VICTORIA AND EURYALE

Organization of the stem vascular system was analyzed in Victoria species and Euryale ferox. The stem vascular system consists of a number of concentrically-organized continuing axial stem bundles. At the node each leaf is supplied with a root trace, two lateral leaf traces, and a median leaf trace. A peduncle fusion bundle is also present at each node. The peduncle fusion bundle supplies vascular tissue to the median leaf trace and to the peduncle trace. Flowers are nonmedian axillary but have specific vascular, spatial, and developmental relationships to leaves in a manner that resembles the genus Nymphaea. On the basis of the analysis of the stem vascular system, Victoria and Euryale are more similar to each other than to Nymphaea. However, the vascular system in Victoria and Euryale is similar enough to Nymphaea to suggest that Nymphaea, Victoria, and Euryale form a natural taxon of unique angiosperms. The organization of the stem vascular system in Victoria and Euryale is dicotyledonous.     

VASCULARIZATION OF ARTICULATED CHENOPODIACEAE AND THE NATURE OF THEIR FLESHY CORTEX

Fahn , A. (Hebrew U., Jerusalem.), and Tova Arzee . Vascularization of articulated Chenopodiaceae and the nature of their fleshy cortex. Amer. Jour. Bot. 46(5): 330–338. Illus. 1959.—The primary vascular system and venation pattern of the following chenopodiacean species with articulated forms were examined: Arthrocnemum glaucum, Salicornia fruticosa, S. herbacea, Halocnemum strobilaceum, Anabasis articulata, A. haussknechtii, A. setifera, taloxylon persicum, H. salicornicum. On the basis of the primary vascular system, classification into 2 types was possible: (a) Salicornia-Arthrocnemum type, in which the number of the stelar strands alternates between 6 and 8; and (b) Anabasis type, in which the number alternates between 4, 6 and 8. The latter type is assumed to be derived from the former. Similarly, on the basis of the venation pattern of the cortex and reduced leaves, 2 types were recognized: (a) Salicornia-Arthrocnemum type, in which the cortical network is connected with the lateral branches of the leaf strands only; and (b) Anabasis type, in which the network is connected with both foliar and stelar strands. The view of the foliar origin of the cortex, as postulated by previous authors, is refuted and the present authors consider the fleshy tissue of the internode to be true cortex.     

THE ORGANIZATION OF THE VASCULAR SYSTEM IN THE STEMS OF THE NYMPHAEACEAE. I. NYMPHAEA SUBGENERA CASTALIA AND HYDROCALLIS

The vascular system in the stems of Nymphaea odorata and N. mexicana subgenus Castalia, and N. blanda subgenus Hydrocallis consists of continuing axial stem bundles with eight being the usual number. The stem bundles are concentric and xylem maturation is mesarch. Xylem elements consist of tracheids with spirally or weakly reticulated secondary wall thickenings. The phloem is made up of companion cells and short sieve tube members with simple sieve plates that are nearly transverse. At the node each leaf is supplied with two lateral leaf traces and a median leaf trace. A root trace is also present and supplies a series of adventitious roots borne on the leaf base. Flowers and vegetative buds develop directly from the apical meristem and occupy leaf sites in a single genetic spiral. Each flower or vegetative bud is related to a leaf through specific spatial and vascular association. The related leaf is separated from the related flower by three members of the genetic spiral and occupies an adjacent orthostichy. Vascular tissue for the related flower arises from the inner surfaces of the four stem bundles supplying leaf traces to the related leaf and extends through the pith to the flower or vegetative bud via a peduncle fusion bundle. The vascular system organization in the investigated species of Castalia and Hydrocallis is not typically monocotyledonous or dicotyledonous, nor can it be considered transitional between them. The ontogeny of the vascular system is similar to typical dicotyledons and the investigated species of Nymphaea can, therefore, be considered to represent highly specialized and modified dicotyledons.     

VASCULARIZATION OF A MULTILACUNAR SPECIES: POLYSCIAS QUILFOYLEI (ARALIACEAE) I. THE STEM

The odd-pinnate leaves of Polyscias quilfoylei have a sheathing leaf base that completely encircles the stem. At each node, many traces depart the vascular cylinder and traverse an obliquely upward course through the leaf base before aggregating in the rachis. Lateral traces diverge from parent traces in the stem vasculature at variable times relative to the leaf they serve, from variable positions in the vascular cylinder and from parent traces of variable ages. The stem vasculature is formed by the coalescing of leaf traces from as many as five leaves. All bundles departing the vascular cylinder at a node to serve a leaf are true leaf traces originating independently in the stem. Leaf traces develop acropetally from their positions of origin on parent traces. Primordial leaves are first served by the median trace and later by lateral traces. Many traces were recognized in the internodes subtending embryonic leaves, but they could not be related either to a specific leaf or to a specific position within a leaf. Because these traces had not yet achieved contact with a primordial leaf site, they were assumed to be in the process of developing acropetally at the time of sampling. Observations suggest that the multiple traces in this species might perform a similar function of integrating the vascular cylinder that subsidiary bundles perform in certain uni- and trilacunar species.     

VASCULAR PATTERNS IN STEMS OF ARACEAE: SUBFAMILIES COLOCASIOIDEAE,AROIDEAE AND PISTIOIDEAE

The stem vasculature of ten genera of Colocasioideae and three genera of Aroideae was analyzed by films of series of cross sections. The technique was unsuited for the numerous tuberous genera of Aroideae (and Pistia), which have shortened internodes. The Colocasioideae has long been recognized as one of the most natural large assemblages in the Araceae, a concept further supported by information from stem anatomy and vasculature. All species examined have amphivasal axial bundles that undergo frequent anastomosis and bifurcation of a seemingly irregular kind. Syngonium is the only viny genus and is exceptional in a number of anatomical features which are associated with its unusual morphology. One of the principle points of diversity in the Colocasioideae is the presence or absence of a permanent cortical vascular system. All four genera with a permanent cortical system (Caladiopsis, Caladium, Xanthosoma, and Syngonium) are neotropical. In the Aroideae (and Pistioideae) all of the tuberous genera have a highly condensed vascular system. Genera with elongated internodes (Stylochiton, Lagenandra, Cryptocoryne) also have a similar pattern, which makes taxonomic comparisons based on stem vasculature in the Aroideae of little value. Branch trace insertion is much less well developed in Colocasioideae and Aroideae than in most other subfamilies.     

小麦的穗领在系统演化和个体发育中形成过程的初步探讨

小麦的穗领有三种类型:领腹完全敞开的U形穗领、领腹完全闭合的O形穗领和领腹呈V型交叉的V形穗领。穗领是系统演化中顶生叶叶鞘减化后的遗迹,也是个体发育中穗轴基部第一侧生小穗下苞叶原始体的痕迹。在一定条件下,从穗领可以长出叶鞘和叶片,穗轴基部节间可以变为茎节间,穗领腋内的小穗可以变为腋芽、带柄分枝穗或分枝花序。其余侧生小穗下都有一个领腹完全敞开的U形小穗领,其形态与U形穗领相似。它们是系统演化中二次轴分枝花序的苞叶叶鞘减化后的遗迹,也是个体发育中苞原始体的痕迹。一定条件下,从小穗领也可以长出叶鞘和叶片。穗轴基部节间变茎的同时,基部几个小穗若发生向圆锥花序的部分返祖变异,随着变异程度加深,从穗领和小穗领逐渐形成叶鞘和叶片。说明在系统演化中。顶生叶和苞叶先减化叶片,后减化叶鞘,最后形成穗领和小穗领。小麦祖先的花序与茎叶之间没有明显的界限。     

ONTOGENY OF THE STEM-NODE-LEAF VASCULAR CONTINUUM OF AUSTROBAILEYA

Developmental study of the stem-node-leaf vascular continuum of Austrobaileya scandens White reveals that the vasculature within each leaf originates from a single procambial strand, that becomes separated into two strands only at the junction of leaf and stem. At lower levels in the stem the two strands become incorporated into independent portions of the stele. At later stages of development the solitary vascular bundle within the young leaf undergoes considerable lateral growth, resulting in an essentially continuous arc of vascular tissue. Ontogenetic evidence indicates that the vascular bundle in the midrib of the lamina should be regarded as a fundamentally single bundle and not interpreted as two bundles that have undergone various degrees of secondary fusion. A condition of two totally separate bundles extending the entire length of the leaf was not encountered. Our observations confirm the characterization of Austrobaileya as an example of “second rank” level of leaf vasculature. Nodal anatomy emphasizes the extremely isolated taxonomic position of Austrobaileya within the primitive dicotyledons.     

COMPARATIVE STUDIES OF THE NODAL AND VASCULAR ANATOMY IN THE NEOTROPICAL CYATHEACEAE. I. METAXYA AND LOPHOSORIA

Comparative studies of the nodal and vascular anatomy in the monotypic genera Metaxya and Lophosoria are discussed as they relate to the taxonomy and phylogeny of the Cyatheaceae. Both genera are distinctive and primitive with respect to habit, stem and petiole indument, stelar pattern, and nodal anatomy. Metaxya possesses a prostrate, dorsiventral rhizome, whereas a short, upright radial stem occurs in Lophosoria. Trichomes occur on the stems and leaf petioles of these genera. Both Metaxya and Lophosoria have a spiral phyllotaxy, and adventitious buds occur on the petiole bases. The stelar pattern is basically a siphonostele, although frequently a dictyostele is found in Lophosoria. Accessory bundles are lacking in both genera. A characteristic petiole pattern is found in these genera, with an increase in complexity from an undivided strand in Metaxya to the three-parted petiole pattern in Lophosoria. Data from nodal and vascular anatomy indicate that these taxa are distinct from the other genera in the Cyatheaceae and belong in an independent position at the base of the Cyatheoid line, although in some respects an affinity to members of the Dicksoniaceae is indicated.     

MORPHOLOGY AND VASCULATURE OF THE LEAF OF POTATO (SOLANUM TUBEROSUM)

The leaf and stem of the potato plant (Solanum tuberosum L. cv. Russet Burbank) were studied by light microscopy to determine their morphology and vasculature; scanning electron microscopy provided supplemental information on the leaf's morphology. The morphology of the basal leaves of the potato shoot is quite variable, ranging from simple to pinnately compound. The upper leaves of the shoot are more uniform, being odd pinnate with three major pairs of lateral leaflets and a number of folioles. The primary vascular system of the stem is comprised of six bundles, three large and three small ones. The three large bundles form a highly interconnected system through a repeated series of branchings and arch-producing mergers. Two of the three large bundles give rise to short, lateral leaf traces at each node. Each of the small bundles in the stem is actually a median leaf trace which extends three internodes before diverging into a leaf. The three leaf traces enter the petiole through a single gap; thus the nodel anatomy is three-trace unilacunar. Upon entering the petiole, each of the laterals splits into an upper and a lower lateral. Whereas the upper laterals diverge entirely into the first pair of leaflets, the lower laterals feed all of the lateral leaflets through a series of bifurcations. Prior to their entering the terminal leaflet, the lower laterals converge on the median bundle to form a single vascular crescent which progresses acropetally into the terminal leaflet as the midvein, or primary vein. In the midrib, portions of the midvein diverge outward and continue as secondaries to the margin on either side of the lamina. Near the tip of the terminal leaflet, the midvein consists of a single vascular bundle which is a continuation of the median bundle. Six to seven orders of veins occur in the terminal leaflet.     

ANATOMY OF THE PRIMARY PHLOEM FIBER SYSTEM IN PISUM SATIVUM

Unusual structure of the primary phloem fiber system in the stem of Pisum sativum is described. The five lowest internodes contain large fiber strands that split radially and may also split tangentially. In both the stem and the root the number of fibers along a strand decreases with the distance below the leaf; in contrast, fiber length increases. Fiber dimensions are also increased in the centripetal direction.     

COMPARATIVE STUDIES OF THE NODAL AND VASCULAR ANATOMY IN THE NEOTROPICAL CYATHEACEAE. III. NODAL AND PETIOLE PATTERNS; SUMMARY AND CONCLUSIONS

Comparative studies of the nodal and vascular anatomy in the Cyatheaceae are discussed as they relate to the taxonomy and phylogeny of the family. There is in the Cyatheaceae (excluding Metaxya and Lophosoria) a basic nodal pattern consisting of four major phases of leaf trace separations. Abaxial traces arise from the leaf gap margins, and the last abaxial traces from each side of the gap are larger and undergo numerous divisions. Distally adaxial traces separate from the gap margins, and the last adaxial traces are usually larger and undergo multiple divisions. In addition, medullary bundles frequently become petiole strands of the adaxial arc in the petiole. Rarely, cortical bundles form petiole strands in the abaxial arc in the petiole. Leaf gaps of the squamate genera of the Cyatheaceae are fusiform and possess prominent lateral constrictions which result from medullary bundle fusions and the separation of leaf traces. A characteristic petiole pattern is found in all members of the Cyatheaceae. There is an increase in the complexity of the petiole vascular tissue which results in a gradation from the undivided strand in Metaxya, to the three-parted petiole pattern in Lophosoria, and finally to the much-dissected petiole vascular tissue in the advanced genera. Nodal and vascular anatomy data basically support Tryon's phyletic scheme for the family. The Sphaeropteris-Alsophila-Nephelea line shows certain tendencies toward increased complexity of nodal and vascular anatomy, whereas the Trichipteris-Cyathea-Cnemidaria line shows the same anatomical and morphological characters in a direction of increased simplification or reduction.     

VASCULAR PATTERNS IN STEMS OF THE CYCLANTHACEAE

A survey was made of the distribution of stem vascular bundles in representatives of ten genera of the tropical monocotyledonous family Cyclanthaceae. Films of series of serial transverse sections were used to reconstruct the stem vasculature. Each leaf trace, followed in a basipetal direction from its level of insertion at the stem periphery, describes an obliquely downward course, initially contacting from 1 to 4 (or more) existing axial bundles. The associated bundles form a compound vascular bundle in which the original bundles initially remain discrete, most commonly in a tetrapolar arrangement, with four separate strands. Followed further in the basipetal direction, the strands eventually fuse partly or completely, usually to form a collateral or amphivasal axial bundle which participates in a new structural cycle. Quantitative variation between different taxa includes a simple pattern in Ludovia, in which only bipolar bundles are developed. More elaborate forms have multipolar bundles with more than four separate strands. A systematically useful observation is that stem vasculature in Cyclanthus, representing the subfamily Cyclanthoideae, does not differ significantly from that in subfamily Carludovicoideae although there are some distinctive structural features.     

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.     

Distribution of Plasma Membrane H+-ATPase and Polar Current Patterns in Leaves and Stems of Elodea canadensis*

The proton pumping ATPase in the plasma membrane of Elodea canadensis is believed to play a major role in inorganic carbon acquisition. To investigate potentially different carbon uptake strategies within the same plant, plasma membrane H⁺-ATPase distribution and polar current patterns were investigated in Elodea leaves and stems. Specific activity of plasma membrane H⁺-ATPase in leaf microsomal fractions was tenfold higher than in stem derived microsomes. Probing western blots with a monoclonal antibody specific for plasma membrane H⁺-ATPase, yielded strongly visible double bands at 100 kDa in leaf microsome preparations, whereas little antigen was detected in analogous stem microsome preparations. Using the same plasma membrane H⁺-ATPase specific antibody on tissue sections, the enzyme was found almost exclusively localized at the border of cells at the lower leaf surface. A positive ion current leaving the lower leaf surface was measured, using a vibrating probe device. Part of this current entered the upper leaf surface and part of it the internodes of the stem. The experimental results support the view, that Elodea leaves have different means of inorganic carbon uptake than stem internodes.     

THE PRODUCTION AND DIFFERENTIATION OF SECONDARY XYLEM IN XANTHIUM PENSYLVANICUM

The removal of leaves and buds from the shoot of Xanthium seedlings caused the cessation of xylem fiber differentiation in all internodes while allowing the production of cambial derivatives to continue toward both the xylem and the phloem. The potential xylem fibers developed into parenchymatous cells with thin cell walls. The vessels developed normally except for their small size. Cambial derivatives and vessels were produced linearly with time in intact plants (6.1 cells per file/day and 9.7 vessels per vascular bundle/day) and in decapitated plants (2.2 cells per file/day and 5.5 vessels per vascular bundle/day). Fiber production was linear with time in intact plants (163 fibers per vascular bundle/day) and did not occur in decapitated plants. When a single leaf was allowed to develop from a lateral bud of a decapitated plant, xylem fiber differentiation was restored for a period of time corresponding to the period of rapid expansion of the leaf blade. When the leaf passed the phase of rapid expansion, it no longer had an inductive effect on xylem fiber differentiation.     

生长调节剂DPC和营养物质KH_2PO_4协同作用对棉苗茎解剖结构的调控效应

在自然光照和遮荫的弱光条件下研究了DPC（助壮素）、KH2PO4（磷酸二氧钾）单独和混合浸种对棉苗茎组织解剖结构的影响,结果表明在两种光照条件下,DPC、KH2PO4对棉苗茎的组织结构都有不同程度的影响。其中以DPC＋KH2PO4处理效果优于单独使用,特别是弱光条件下,此效应更明显。DPC＋KH2PO4处理使棉苗茎秆粗壮,茎秆密度（单位茎高度内予物质重）增加．茎中维管组织发育好,维管束数目多,每一维管束中分化的导管数目增多;木质部、韧皮部面积大并且发育较好,因而加强了茎的生理功能;有利于培青壮苗。     

POLLEN MORPHOLOGY AND THE RELATIONSHIPS OF CIRCAEASTER,OF KINGDONIA,AND OF SARGENTODOXA TO THE RANUNCULALES

The pollen of three monotypic genera, Circaeaster, Kingdonia, and Sargentodoxa has been examined by light and scanning electron microscopy and in the case of the last genus, also by transmission electron microscopy. The type of tectum found in Circaeaster and Kingdonia, derivations of a compound layer of striae, has a restricted distribution in the Order Ranunculales. Of 64 genera examined in this order only six had species with a similar tectum. They include Achlys, Epimedium, Jeffersonia, and Vancouveria of the Berberidaceae s.l., the controversial Hydrastis, and Trollius of the Ranunculaceae. Circaeaster and Kingdonia have been considered as related since both have rare and primitive vegetative characteristics, the most notable being open dichotomous leaf venation. They are probably best treated as a ditypic family, Circaeasteraceae. The pollen of Sargentodoxa, especially the structure of the exine, closely resembles that of the Lardizabalaceae. However, the fruits of Sargentodoxa have been considered to be distinct from those of the Lardizabalaceae, suggesting that it be treated as a separate, but closely allied, family.     

THE RELATIONSHIP BETWEEN THE PRIMARY THICKENING MERISTEM AND THE SECONDARY THICKENING MERISTEM IN YUCCA WHIPPLEI TORR. I. HISTOLOGY OF THE MATURE VEGETATIVE STEM

Anatomical observations were made on 1-, 2-, and 3-yr-old plants of Yucca whipplei Torr, ssp. percursa Haines grown from seed collected from a single parent in Refugio Canyon, Santa Barbara, California. The primary body of the vegetative stem consists of cortex and central cylinder with a central pith. Parenchyma cells in the ground tissue are arranged in anticlinal cell files continuous from beneath the leaf bases, through the cortex and central cylinder to the pith. Individual vascular bundles in the primary body have a collateral arrangement of xylem and phloem. The parenchyma cells of the ground tissue of the secondary body are also arranged in files continuous with those of the primary parenchyma. Secondary vascular bundles have an amphivasal arrangement and an undulating path with frequent anastomoses. Primary and secondary vascular bundles are longitudinally continuous. The primary thickening meristem (PTM) is longitudinally continuous with the secondary thickening meristem (STM). Axillary buds initiated during primary growth were observed in the leaf axils. The STM becomes more active prior to and during root initiation. Layers of secondary vascular bundles are associated with root formation.