The peripheral xylem of grapevine (Vitis vinifera) berries. 2. Anatomy and development

It has been hypothesized that the substantial reductions in xylemic water flow occurring at veraison are due to physical disruption (breaking) of the xylem as a result of renewed berry growth. In a companion paper, evidence was presented that the vast majority of xylem tracheary elements remained intact despite the growth of the berry, and it was proposed that existing tracheary elements stretch to accommodate growth and that additional elements may also differentiate after veraison. Measurements of the intergyre distance of tracheary elements in macerated tissue were used to test for stretching, and the numbers of tracheary elements per vascular bundle and of branch points of the peripheral xylem network were analysed to test for continued differentiation from 18 to 120 d after anthesis in Chardonnay berries. The distance between the epidermis and the vasculature increased substantially from pre- to post-veraison, potentially increasing the amount of skin available for analysis of compounds important for winemaking. Tracheary elements continued to differentiate within the existing vascular bundles throughout berry development. Additional vascular bundles also appeared until after veraison, thereby increasing the complexity of the peripheral vascular network. The results also confirmed that tracheary elements stretched by approximately 20%, but this was not as much as that predicted based on the growth of the vascular diameter (40%). These results complete a comprehensive evaluation of grape berry peripheral xylem during its development and show that tracheary development continues further into berry maturation than previously thought.     

Evolution of Piperales--matK gene and trnK intron sequence data reveal lineage specific resolution contrast

Piperales represent the largest basal angiosperm order with a nearly worldwide distribution. The order includes three species rich genera, Piper (ca. 2000 species), Peperomia (ca. 1500-1700 species), and Aristolochia s. l. (ca. 500 species). Sequences of the matK gene and the non-coding trnK group II intron are analysed for a dense set of 105 taxa representing all families (except Hydnoraceae) and all generic segregates (except Euglypha within Aristolochiaceae) of Piperales. A large number of highly informative indels are found in the Piperales trnK/matK dataset. Within a narrow region approximately 500 nt downstream in the matK coding region (CDS), a length variable simple sequence repeat (SSR) expansion segment occurs, in which insertions and deletions have led to short frame-shifts. These are corrected shortly afterwards, resulting in a maximum of six amino acids being affected. Furthermore, additional non-functional matK copies were found in Zippelia begoniifolia, which can easily be discriminated from the functional open reading frame (ORF). The trnK/matK sequence data fully resolve relationships within Peperomia, whereas they are not effective within Piper. The resolution contrast is correlated with the rate heterogeneity between those lineages. Parsimony, Bayesian and likelihood analyses result in virtually the same topology, and converge on the monophyly of Piperaceae and Saururaceae. Lactoris gains high support as sister to Aristolochiaceae subf. Aristolochioideae, but the different tree inference methods yield conflicting results with respect to the relationships of subfam. Asaroideae. In Piperaceae, a clade formed by the monotypic genus Zippelia and the small genus Manekia (=Sarcorhachis) is sister to the two large genera Piper and Peperomia.     

The peripheral xylem of grapevine (Vitis vinifera). 1. Structural integrity in post-veraison berries

During the development of many fleshy fruits, water flow becomes progressively more phloemic and less xylemic. In grape (Vitis vinifera L.), the current hypothesis to explain this change is that the tracheary elements of the peripheral xylem break as a result of berry growth, rendering the xylem structurally discontinuous and hence non-functional. Recent work, however, has shown via apoplastic dye movement through the xylem of post-veraison berries that the xylem should remain structurally intact throughout berry development. To corroborate this, peripheral xylem structure in developing Chardonnay berries was investigated via maceration and plastic sectioning. Macerations revealed that, contrary to current belief, the xylem was comprised mostly of vessels with few tracheids. In cross-section, the tracheary elements of the vascular bundles formed almost parallel radial files, with later formed elements toward the epidermis and earlier formed elements toward the centre of the berry. Most tracheary elements remained intact throughout berry maturation, consistent with recent reports of vascular dye movement in post-veraison berries.     

Further observations on hydrolysis of the cell wall in the xylem

Summary Hydrolyzed walls (birefringent, Periodic acid/Schiff negative, remnants of primary walls that also lack polyuronides with free carboxyl groups) are demonstrated in the primary xylem of wheat and bean leaves. Walls with similar properties have been found in the primary xylem of a variety of tissues from different species, and are believed to be ubiquitous. It is shown that the pit membrane of intervessel pits between tracheary elements of willow is also a hydrolyzed wall. Combined with the observation byLiese (1965) it seems likely that the removal of non-cellulosic polysaccharides from primary walls unprotected by lignin is a general phenomenon that occurs late in the autolysis of all tracheary elements. Parenchyma cells that abut autolyzing tracheary elements appear to react to hydrolytic attack in a number of ways that are illustrated and discussed.     

Comparison of vegetative anatomy of Piperales. II. Leaf

Many characters of leaf (hair, hypodermal cells, palisade layers, intercellular space, distinction between spongy and palisade parenchyma, "palisade ratio", distribution of collenchyma and sclerenchyma, presence or absence of starch grains, calcium oxalate crystals, number, shape and arrangement of bundles of petiole) are useful distinguishing characters. Reduction of palisade layers seems to be the trend of evolution in Piper and Peperomia.     

胡椒科的花粉形态及其分类学意义

胡椒科的某些属之间,花粉形态表现出一定的差异。齐头绒属花粉粒表面粒为平滑,但有小穿孔,略显粗糙。胡椒属的花粉粒表面有不规则的瘤状纹饰,纹饰较为平滑。Ｌｅｐｉａｎｔｈｅｓ（Ｐｏｔｈｏｍｏｒｐｈｅ）的花粉粒表面瘤状纹饰不显著。     

Studies in neotropical Piperaceae. II. Four new species and a new combination from Colombia and Peru

Peperomia boekei, an endemic from Peru, andPeperomia antioquiensis, Piper perpusillum, andPiper valdivianum, all known only from the Department of Antioquia (Colombia), are described and illustrated, and their relationships are discussed. A new combination,Piper enckeaespicum (Trel. & Yuncker) Callejas, is proposed.     

一条卡瓦胡椒特异RAPD带转化成SCAR标记的研究

采用27份不同来源的胡椒属(Piper)材料和1份不同属的草胡椒(Peperomia pellucida)材料用引物OPQ-03扩增得到一条约400碱基对(bp)卡瓦胡椒特异片段。对该片段进行了克隆和序列分析,并根据序列分析结果将上述RAPD分子标记转化为重复性和特异性更好的SCAR(sequence characterized amplifiedre-gions,序列特征化扩增区)分子标记。本研究设计出了1对卡瓦胡椒特异SCAR引物P7.1(5′-GGT CAC CTC ACC GCA GCA GGA TGA ACG-3′)和P7.2(5′-GGT CAC CTC AAT GAC ATG GGA TGA ATC-3′),用这对特异引物对本次试验的28份材料进行PCR扩增,结果只有不同属的草胡椒材料无任何扩增,其它材料均扩增出了预期大小440bp的特异带。     

Graniferous Tracheary Elements in the Haustorium of Osyris arborea Wall. (Santalaceae)

In the haustorium of Osyris arborea (a non-host specific roothemi-parasite) a distinct interrupted zone is present abovethe vascular core. The majority of the xylem elements in thevascular core are perforated. Graniferous tracheary elementsin this species are recorded for the first time. Cytochemicaltests showed the granules to be proteinaceous. The suggestedfunction of graniferous tracheary elements in the regulationof pressure and flow of sap is discussed. Osyris arborea, root hemi-parasite, Santalaceae, haustorium, graniferous tracheary elements, protein granules     

Cortical Bundles in the Persistent, Photosynthetic Stems of Cacti

We examined 62 species in 45 genera of the cactus subfamilyCactoideae; all had collateral cortical bundles that permeatedthe broad, water-storing inner cortex and extended to the baseof the outer, photosynthetic palisade cortex. Mean distancebetween cortical bundles was 0.75 mm, similar to the mean spacing(0.74 mm) of veins in leaves of Pereskia, a genus of relictleaf-bearing cacti. In 16 species, both young and extremelyold stem cortex was available for study: in all of these, olderbundles had larger amounts of phloem than did younger bundles,indicating that phloem had been produced for many years. Inten species, older bundles also had more xylem than youngerbundles. In two genera (Rhipsalis and Selenicereus) there werecaps of primary phloem fibres, and in a single species (Pilosocereusmortensenii) cortical bundle xylem contained libriform fibres.All cortical bundle tracheary elements were narrow (radius range,0.91–8.2 µm; mode, 1.8–2.7 µm), similarto Pereskia leaf vein elements (radius range, 1.8–2.7µm); this was much narrower than stem wood vessels (radiusrange, 10–42 um; mode, 23–28 µm). Longitudinalconduction of water and nutrients probably occurs predominantlyin stem wood, with cortical bundles maintaining the broad, voluminouscortex, the outer part of which is the plant's photosynthetictissue and the inner part of which stores water and starch.The cortex of the Cactordeae contains numerous leaflike characters;homeotic genes may be involved in its morphogenesis. Cactaceae, cortical bundles, homeotic, xylem, phloem, evolution     

一条卡瓦胡椒特异RAPD 带转化成SCAR 标记的研究

采用27 份不同来源的胡椒属( Piper) 材料和1 份不同属的草胡椒( Peperomia pellucida) 材料用引物OPQ-03 扩增得到一条约400 碱基对( bp) 卡瓦胡椒特异片段。对该片段进行了克隆和序列分析, 并根据序列分析结果将上述RAPD 分子标记转化为重复性和特异性更好的SCAR ( sequence characterized amplified regions, 序列特征化扩增区) 分子标记。本研究设计出了1 对卡瓦胡椒特异SCAR 引物P7. 1 ( 5′-GGT CAC CTC ACC GCA GCA GGA TGA ACG-3′) 和P7 . 2 (5′-GGT CAC CTC AAT GAC ATG GGA TGA ATC-3′) , 用这对特异引物对本次试验的28 份材料进行PCR 扩增, 结果只有不同属的草胡椒材料无任何扩增, 其它材料均扩增出了预期大小440 bp 的特异带。     

Study on the RAPD Specific Band of Kava ( Piper,Piperaceae) Transferring to the SCAR Molecular Marker

This paper studied on 28 pepper materials, including 16 cultivated papper materials, 3 wild pepper materials, 2 wild relatives of pepper materials , 6 kava ( Piper methysticum) materials, and 1 Peperomia pellucida materials. According to RAPD analysis, we generate SCAR marker for identifying Kava ( Piper, Piperaceae ) . A Kava-associated fragment with a length ofabout 400 bp was generated with OPQ-03 primer . The fragment was cloned and sequenced . PCR amplification with the specific primers P7 . 1 ( 5′-GGT CAC CTC ACC GCA GCA GGA TGA ACG-3′) and P7 .2 (5′-GGT CAC CTC AAT GAC ATG GGA TGA ATC-3′) was performed to 28 materials , which 27 materials amplified the 440 bp specific band except for Peperomia pellucida Kunth .     

In vitro induction of secondary xylem-like tracheary elements in calli of hybrid poplar (Populus sieboldii × P. grandidentata)

The formation of tracheary elements was induced in calli derived from petioles of hybrid poplar (Populus sieboldii × P. grandidentata) after 10 days of culture on medium that lacked auxin but contained 1 μM brassinolide. Some differentiated cells formed broad regions of cell walls and bordered pits, which are typical features of tracheary elements of secondary xylem. Other differentiated cells resembled tracheary elements of primary xylem, with spiral or reticulate thickening of cell walls. The tracheary elements that developed in calli were formed within cell clusters. This induction system provides a new model for studies of the mechanism of differentiation of secondary xylem cells in vitro.     

Comparative Anatomical Studies on Root Structure of Ranunculaceae

This paper deals with comparative studies of the root structure in 65 species of 36 genera of Ranunculaceae. Five types of the root structure were recognized in these species. A. The roots, in which the primary xylem was surrounded by the tracheary elements of the secondary xylem and the ray was absent, were always diarchy, as seen in Coptis. B. The rays were narrow and the tracheary elements of the secondary xylem were semicircle in shape, and the roots were diarchy, as seen in Leptopyrum. C. The rays and tracheary elements of the secondary xylem were sector in shape, and the roots were di-, tri-, and tetrarchy, as seen in Cimicifuga, etc. D. There was a few secondary xylem in the roots. D1. Primary structure was diarchy, in Kingdonia. D2. The roots were di-, tri-, tetra- and pentarchy, in Ranunculus etc. E. The secondary structure was absent. El. The roots were diarchy, in Asteropyrum. E2. They were di-, tri-, tetra- and pentarch, as seen in Caltha. According to comparative anatomical studies on the characteristics of the vessel elements and other parts of plant (carpel, petiole and vena- tion), the roots which were always diarcby whether in older or young, and whether the tra- .cheary elements of the secondary xylem well orless developed, could be considered as the most primitive type, for example: type A (Coptis) and type El (Asteropyrum). It would be con- cluded that the evolution of the root structure from primitive to specialized type was in the order from type A→B→C→D2→E2 and E1→D1 in Ranunculaceae.     

From Forgotten Taxon to a Missing Link? The Position of the Genus Verhuellia (Piperaceae) Revealed by Molecules

BACKGROUND AND AIMS: The species-poor and little-studied genus Verhuellia has often been treated as a synonym of the genus Peperomia, downplaying its significance in the relationships and evolutionary aspects in Piperaceae and Piperales. The lack of knowledge concerning Verhuellia is largely due to its restricted distribution, poorly known collection localities, limited availability in herbaria and absence in botanical gardens and lack of material suitable for molecular phylogenetic studies until recently. Because Verhuellia has some of the most reduced flowers in Piperales, the reconstruction of floral evolution which shows strong trends towards reduction in all lineages needs to be revised. METHODS: Verhuellia is included in a molecular phylogenetic analysis of Piperales (trnT-trnL-trnF and trnK/matK), based on nearly 6000 aligned characters and more than 1400 potentially parsimony-informative sites which were partly generated for the present study. Character states for stamen and carpel number are mapped on the combined molecular tree to reconstruct the ancestral states. KEY RESULTS: The genus Peperomia is generally considered to have the most reduced flowers in Piperales but this study shows that this is only partially true. Verhuellia, with almost equally reduced flowers, is not part of or sister to Peperomia as expected, but is revealed as sister to all other Piperaceae in all analyses, putting character evolution in this family and in the perianthless Piperales in a different light. A robust phylogenetic analysis including all relevant taxa is presented as a framework for inferring patterns and processes of evolution in Piperales and Piperaceae. CONCLUSIONS: Verhuellia is a further example of how a molecular phylogenetic study can elucidate the relationships of an unplaced taxon. When more material becomes available, it will be possible to investigate character evolution in Piperales more thoroughly and to answer some evolutionary questions concerning Piperaceae.     

RELATION OF DWARFMISTLETOE (ARCEUTHOBIUM) TO THE XYLEM TISSUE OF CONIFERS. I. ANATOMY OF PARASITE SINKERS AND THEIR CONNECTION WITH HOST XYLEM

Srivastava , L. M., and K. Esau . (U. California, Davis.) Relation of dwarf mistletoe (Arceuthobium) to the xylem tissue of conifers. I. Anatomy of parasite sinkers and their connection with host xylem. Amer. Jour. Bot. 48(2): 159–167. Illus. 1961.—The anatomy of the sinkers of Arceuthobium infecting 7 species of conifers was studied by the use of serial cross, radial, and tangential sections of the host wood. The sinkers were found to be composed of parenchyma cells only, or of parenchyma cells and tracheary elements, including vessel elements. In all species tracheary cells of the sinkers had direct contacts with the host tracheids of axial and radial systems. Typically the sinkers were associated with rays of the host wood. In some species, the centripetal ends of sinkers were wedged in radially among the axial tracheids of the host, but centrifugally such sinkers were usually found associated with rays. In the region of the host cambium the sinker contained parenchyma cells meristematic in appearance and, in 6 out of 7 species, also mature tracheary elements. The oldest of these elements became stretched and ruptured, a circumstance indicating that growth occurred in the part of the sinker embedded in the host cambium. This growth appeared to be coordinated with that of the host cambium, so that the sinker became embedded in the host xylem and phloem. Radial centripetal penetration of sinkers among differentiating axial tracheids of the host possibly occurred to a limited extent.     

红树族植物次生木质部附物纹孔的电镜观测

应用扫描电子显微镜详细观察了红树族4属、10种、1变种植物次生木质部管状分子附物纹孔的分布和形态, 应用Carnoy 2.0软件和扫描电镜下采集的照片, 测定了管间梯状附物纹孔丰富度指标和管间梯状纹孔数量特征指标。结果显示, 红树族植物次生木质部管状分子侧壁具附物纹孔。所观察的植物附物纹孔的分布和形态变化大。附物纹孔丰富度指标与管间梯状纹孔数量特征指标的逐步回归分析表明, 导管侧壁附物纹孔丰富度随纹孔口面积百分比的增大而增大。据此推测, 红树族植物附物纹孔丰富度与纹孔几何构造及数量特征有关。附物纹孔是红树族植物稳定存在的一个木材解剖性状。综合生态-系统演化的观点, 红树族植物具附物纹孔可能是受系统演化关系控制的生态适应结果。     

Filament histology and anther dehiscence

Several distinctive histological features of the stamen, especially of the filament, are described, some of these for the first time: for example, commonness of (a) mesarch xylem maturation, amphicribral bundles or else collateral strands with phloem considerably enveloping the xylem, and clustering of sieve elements of a bundle and their spatial separation from tracheary elements, (b) exclusively helical wall thickenings of tracheary elements and absence of sclerenchyma, (c) open stomata, a weakly developed cuticle, a prominent intercellular-space system, xylem lacunae, and (d) tannins and crystals. Some of the features in category (a) seem related to the nutritional needs of developing pollen grains in the anther. Features in category (b) are directly related to the usual expansion of the stamen, in particular the filament, before and at anthesis. Features in category (c) (and possibly (d)) probably promote a rapid loss of water or a disruption of the water supply to the anther, and therefore might facilitate anther dehiscence (these features could operate either in isolation or in unison). Tannins, crystals, and secretory structures have been implicated in the protection of pollen against predators.     

Fine Structure of Hydrolysed Primary Walls in Tracheary Elements of Petiolar Xylem in Eucalyptus delegatensis

The hydrolysed lateral primary walls of tracheary elements ofthe petiolar xylem of Eucalyptus delegatensis were examinedby electron microscopy. Vessel-vessel and vessel—tracheidhydrolysed walls were strikingly different in appearance fromtracheid—tracheid walls. The difference seemed to be inthe degree to which the primary walls were hydrolysed. The observationssuggest the wall hydrolysis to be an ordered and controlledprocess. Eucalyptus delegatensis, hydrolysed wall, petiolar xylem, tracheary elements     

马蹄香属营养器官解剖及其分类位置的探讨

对马蹄香属Ｓａｒｕｍａ Ｏｌｉｖ．营养器官的形态解剖进行了研究,首次报道该属植物叶片宏观结构;叶表皮和叶表面的微观结构;叶柄和茎的初生结构特征与次生结构特征,并与近缘属植物细辛属Ａｓａｒｕｍ Ｌ．的解剖学资料作了比较研究,发现两属的叶形均为心形;叶脉都是掌状脉序;叶沿无齿都具毛;且都是单毛;气孔器都是“毛茛科”型;叶柄维管束都呈“Ｖ”字形排列;从近轴端到远轴端都是呈３－４－４束的变化;茎的初生结构