Micromorphology of epicuticular waxes in Centrosperms

Epidermal surfaces of about 500 species from some 250 genera of centrospermous families plus some possibly related families were examined by scanning electron microscopy. The micromorphology of their epicuticular waxes is described under taxonomic aspects. In general, Centrosperms tend to develop wax platelets on their cuticle. Shape and size of these platelets are highly diverse, but specific for some taxa. Particular forms of rodlets and thick wax plates occur only in few taxa. The systematic and taxonomic applicability of wax micromorphology is limited, but tentatively family characterizations are given. The data presented provide additional information concerning the familiar and suprafamiliar classification ofCaryophyllales. Dedicated to the enthusiast of succulent Centrosperms, Prof. DrK. E. Wohlfarth-Bottermann (Director of the Institute of Cytology and Micromorphology, University of Bonn) on the occasion of his 65th birthday in May 1988.     

Surface wax, a new taxonomic feature in Plagiochilaceae

A scanning electron microscope study of 81 species of Plagiochilaceae revealed the presence of superficial waxes on the leaves and stems ofPlagiochilion mayebarae and 5 species ofPlagiochila. The waxes are not visible in the light microscope and were unknown in Plagiochilaceae.Plagiochila fuscolutea andP. longiramea (=P. sect.Fuscoluteae) are characterised by the predominant occurrence of membraneous wax platelets;Plagiochila aerea, P. rudischusteri andP. tabinensis(=P. sect.Bursatae) predominately form various types of wax rodlets. Our findings show for the first time the systematic usefulness of leaf surface waxes in the liverworts.P. tabinensis contains surface waxes in amounts of ca. 1.4% dry weight composing of steryl esters, triacylglycerols and free fatty acids.     

核盘菌侵染对拟南芥表皮蜡质结构及化学组成的影响

以野生型拟南芥与蜡质突变体cer1、cer4为试验材料,通过研究核盘菌胁迫对拟南芥茎表皮蜡质结构及组分含量的影响,揭示核盘菌侵染与表皮蜡质的关系。扫描电镜结果显示,野生型拟南芥蜡质晶体以垂直于表面的杆状、块状结构为主;突变体cer1晶体类型以水平的松针状、块状结构为主;突变体cer4蜡质晶体以垂直片层结构为主。核盘菌胁迫下,拟南芥蜡质晶体结构及分布形态发生变化。蜡质层结构在核盘菌胁迫下表现为:杆状、松针状蜡质晶体减少—蜡质晶体熔融—表皮"囊状凸起"—表皮膜层破裂。这些结构变化有利于病菌突破角质层屏障而侵入到植株体内。色质谱分析结果显示:与野生型相比,cer1突变体烷、次级醇、酮类显著减少;cer4突变体表现为一级醇含量减少。接种核盘菌后,野生型拟南芥与蜡质突变体一级醇类显著增加(cer1增加不显著);烷类、次级醇类、酮类含量与蜡质总量均显著减少,表明蜡质前体物质在受到核盘菌胁迫后更多地通过酰基还原途径生成一级醇,从而减少了由脱羰基途径所生成的蜡质组分。核盘菌通过改变表皮蜡质晶体结构与化学组分分泌量来促进侵染。     

A phylogenetic analysis of the lichen familySphaerophoraceae (Caliciales); a new generic classification and notes on character evolution

A phylogenetic analysis of the familySphaerophoraceae (Caliciales, lichenized ascomycetes) has resulted in a new generic classification. Notes on character evolution are given. The generaSphaerophorus s. str.,Bunodophoron andLeifidium, gen. nov., are accepted.Pleurocybe andPseudosphaerophorus are considered synonyms ofBunodophoron andThysanophoron is considered synonym toSphaerophorus. The following new combinations are proposed:Bunodophoron coomerense (Ohlsson)Wedin,B. diplotypum (Vain.)Wedin,B. dodgei (Ohlsson)Wedin,B. flaccidum (Kantvilas & Wedin)Wedin,B. formosanum (Zahlbr.)Wedin,B. imshaugii (Ohlsson)Wedin,B. insigne (Laurer)Wedin,B. kinabaluense (M. Satô)Wedin,B. macrocarpum (Ohlsson)Wedin,B. madagascareum (Nyl.)Wedin,B. microsporum (Ohlsson)Wedin,B. murrayi (Ohlsson)Wedin,B. notatum (Tibell)Wedin,B. ohlssonii (Wedin)Wedin,B. patagonicum (C. W. Dodge)Wedin,B. ramuliferum (I. M. Lamb)Wedin,B. scrobiculatum (C. Bab.)Wedin,B. tibellii (Wedin)Wedin,B. whakapapaense (Wedin)Wedin, andLeifidium tenerum (Laurer)Wedin.     

The structure,composition and distribution of proteinaceous crystalloids in vegetative cells of the red algaWrangelia plumosa

Summary High concentrations of proteinaceous crystalloids accumulate in vegetative cells of the red algaWrangelia plumosa Harvey but disappear prior to sporogenesis. The distinctly structured crystalloids lack a bounding membrane and appear to autopolymerize within the cytoplasm. Chemical analysis of isolated crystalloids showed the presence of all amino acids except cysteine and cysteic acid. Carbohydrate accounted for 7.5% of the preparation. The crystalloids appear to have a storage function during growth and development.     

Novel<Emphasis Type="Italic"> eceriferum</Emphasis> mutants in<Emphasis Type="Italic"> Arabidopsis thaliana</Emphasis>

We conducted a novel non-visual screen for cuticular wax mutants in Arabidopsis thaliana (L.) Heynh. Using gas chromatography we screened over 1,200 ethyl methane sulfonate (EMS)-mutagenized lines for alterations in the major A. thaliana wild-type stem cuticular chemicals. Five lines showed distinct differences from the wild type and were further analyzed by gas chromatography and scanning electron microscopy. The five mutants were mapped to specific chromosome locations and tested for allelism with other wax mutant loci mapping to the same region. Toward this end, the mapping of the cuticular wax (cer) mutants cer10 to cer20 was conducted to allow more efficient allelism tests with newly identified lines. From these five lines, we have identified three mutants defining novel genes that have been designated CER22, CER23, and CER24. Detailed stem and leaf chemistry has allowed us to place these novel mutants in specific steps of the cuticular wax biosynthetic pathway and to make hypotheses about the function of their gene products.Abbreviations EMS Ethyl methane sulfonate - SEM Scanning electron microscopy - SSLP Simple sequence length polymorphism - WT Wild type     

垂叶榕叶片表面蜡质化学组分及蓟马锉吸胁迫对其含量的影响

为明确垂叶榕(Ficus benjamina)叶片表面蜡质的化学组分和蓟马(Thrips spp.)锉吸胁迫对蜡质含量的影响,采用气相色谱-质谱联用仪(GC-MS)对不同危害等级蓟马锉吸叶片的表面蜡质化学组分及含量进行了检测和比较分析。结果表明,垂叶榕叶片的表面蜡质中含有32种化合物,包含有9种酸、8种醇、5种酯、5种酮和5种烃。不同危害等级叶片的表面蜡质总量、已分离化合物的总离子峰面积、各类化合物的相对含量、各类化合物及其主要组分的离子峰面积均不同。垂叶榕叶片的表面蜡质的化学组分和含量可直接或间接反映叶片受蓟马锉吸危害的程度。这说明叶片表面蜡质的化学组分及含量在垂叶榕与蓟马的互作和协同进化中扮演着重要角色。     

Two sides of a leaf blade: <Emphasis Type="Italic">Blumeria graminis</Emphasis> needs chemical cues in cuticular waxes of <Emphasis Type="Italic">Lolium perenne</Emphasis> for germination and differentiation

Plant surface characteristics were repeatedly shown to play a pivotal role in plant–pathogen interactions. The abaxial leaf surface of perennial ryegrass (Lolium perenne) is extremely glossy and wettable compared to the glaucous and more hydrophobic adaxial surface. Earlier investigations have demonstrated that the abaxial leaf surface was rarely infected by powdery mildew (Blumeria graminis), even when the adaxial surface was densely colonized. This led to the assumption that components of the abaxial epicuticular leaf wax might contribute to the observed impairment of growth and development of B. graminis conidia on abaxial surfaces of L. perenne. To re-assess this hypothesis, we analyzed abundance and chemical composition of L. perenne ab- and adaxial epicuticular wax fractions. While the adaxial epicuticular waxes were dominated by primary alcohols and esters, the abaxial fraction was mainly composed of n-alkanes and aldehydes. However, the major germination and differentiation inducing compound, the C₂₆-aldehyde n-hexacosanal, was not present in the abaxial epicuticular waxes. Spiking of isolated abaxial epicuticular Lolium waxes with synthetically produced n-hexacosanal allowed reconstituting germination and differentiation rates of B. graminis in an in vitro germination assay using wax-coated glass slides. Hence, the absence of the C₂₆-aldehyde from the abaxial surface in combination with a distinctly reduced surface hydrophobicity appears to be primarily responsible for the failure of normal germling development of B. graminis on the abaxial leaf surfaces of L. perenne.     

Trebouxia aggregata undGloeocapsa sanguinea,Phycobionten inEuopsis granatina (Lichinaceae)

The green algaTrebouxia aggregata (Archibald)Gärtner (Chlorellales) and the procaryotic blue-green alga (cyanobacterium)Gloeocapsa sanguinea (C. Agardh)Kütz. emend.Jaag (Chroococcales) are reported to be the phycobionts inEuopsis granatina (Sommerf.)Nyl. (Lichinaceae). The ultrastructure of the two organisms, studied in the lichen thallus, is described.

Frau Prof. Dr.Elisabeth Tschermak-Woess zu ihrem 70. Geburtstag gewidmet.     

Heterostyly in species ofNarcissus (Amaryllidaceae) andHugonia (Linaceae) and other disputed cases

The hypothesis ofHenriques andFernandes that several Iberian species ofNarcissus (Amaryllidaceae) are tristylous is reconsidered. Contrary to the opinion ofBateman and most subsequent authors, we believe that the available evidence indicates that some populations ofN. triandrus andN. fernandesii, at least, are tristylous; other populations ofN. triandrus are distylous.Hugonia cf.penicillanthemum (Linaceae) from new Caledonia is distylous, but it remains possible that other species ofHugonia are tristylous. The disputed occurrence of heterostyly in S. African species ofBauhinia (Leguminosae),Cleome (Capparaceae) andAneilema (Commelinaceae), and inAgelaea (Connaraceae) is discussed.     

On the Lichen generaPlacocarpus andPlacidiopsis (Verrucariaceae)

Verrucaria schaereri (Fr.)Nyl. is accorded generic status asPlacocarpus Trev. emend.O. Breuss. The main differences between the two genera concern the thallus anatomy and the spores which are halonate inPlacocarpus. The following new combinations are proposed:Placocarpus schaereri (Fr.)O. Breuss andPlacidiopsis cinerascens (Nyl.)O. Breuss.     

Some interesting agarics from eastern Austria

Four very rare species ofAgaricales of dry grassland of the Galgenberg near Röschitz (Niederösterreich) are described and their taxonomy, affinities, ecology and distribution are discussed.Marasmiellus graminis (Murr.)Sing. & Hausknecht andCrinipellis subtomentosa (Peck.)Sing. var.mauretanica (Mre.)Sing. & Hausknecht are proposed as new combinations;Campanella inquilina Romagn. apudRedhead is a synonym ofC. caesia Romagn.     

A reconsideration of the genusRabdosiella (Lamiaceae,Nepetoideae, Ocimeae)

The two generaPlectranthus andIsodon are compared and found to be very dissimilar.Isodon ist considered to be misplaced inOcimeae subtribePlectranthinae and apparently is more closely related to subtribeHyptidinae. The disjunct genusRabdosiella is compared to these two genera and regarded to be polyphyletic. The AfricanR. calycina (Benth.)Codd is returned toPlectranthus and calledP. calycinus Benth., while the AsianR. ternifolia (D. Don)Codd is placed inIsodon sect.Pyramidium and calledI. ternifolius (D. Don)Kudo.     

Ultrastructure of sieve-element plastids inCaryophyllales (Centrospermae), evidence for the delimitation and classification of the order

The orderCaryophyllales (Centrospermae) was found to contain specific P-type sieve-element plastids which are characterized by protein inclusions composed of ring-shaped bundles of filaments and of central crystalloids. The sieve-element plastids of 14 families (140 species investigated) fit into this overall characterization, and more specific details are used to delimit the families and arrange them within the order.Phytolaccaceae, the basic family of the order display much diversity: the crystalloids inside their plastids are either globular (most genera) or polygonal (Stegnosperma), starch may also be present (Phytolacca).Nyctaginaceae, with starch inBougainvillea sieve-element plastids, can be derived directly fromPhytolacca. Globular crystalloids are present in most of the families, as inDidiereaceae, Cactaceae, Aizoaceae-Tetragoniaceae, Portulacaceae-Basellaceae-Halophytaceae-Hectorellaceae. Caryophyllaceae andLimeum ofMolluginaceae contain polygonal crystalloids (otherMolluginaceae with globular crystalloids). Crystalloids are entirely absent fromChenopodiaceae (incl.Dysphaniaceae) andAmaranthaceae. The probable relationships between these families are presented diagrammatically in Fig. 13. Bataceae, Gyrostemonaceae, Vivianiaceae, Theligonaceae, Polygonaceae, Plumbaginaceae, Fouquieriaceae, Frankeniaceae, andRhabdodendraceae—all at some time included into theCaryophyllales (Centrospermae) or doubtfully referred to them—develop S-type (or different P-type) sieve-element plastids. Their direct connection to theCaryophyllales therefore is excluded. Finally, evolutionary trends of theCaryophyllales are discussed.Presented in the Symposium Evolution of Centrospermous Families, during the XIIth International Botanical Congress, Leningrad, July 8, 1975.     

Biostatistical studies on western EuropeanDactylorhiza (Orchidaceae)—theD. maculata group

Multivariate analysis tools are exploited on a data set composed of quantitative characteristics collected on 35 populations of plants of theDactylorhiza maculata (L.)Soó group from Western-Europe. These samples lead to four well-defined clusters; this, together with qualitative, cytological and ecological arguments, allows for the recognition of four specific entities:D. maculata s.str.,D. fuchsii (Druce)Soó,D. saccifera (Brongn.)Soó andD. caramulensis (Vermeulen)Tyteca. It is concluded that the floral characters play an essential role in the taxonomical distinction. It also appears that the set of characters measured, as well as the methods exploited, are especially well-suited and valuable tools for the morphological study of the genusDactylorhiza.     

Epiphytic cyanophytes Xenococcus kerneri and Chamaesiphon minutus on the freshwater red alga Paralemanea catenata (Rhodophyta)

Epiphytes of Paralemanea catenata (Kützing) Vis & Sheath (Rhodophyta) were studied on material from the River Dyje in National Park Podyjí. Longitudinal sections of the thalli were made with help of Cryo Cut Microtome techniques. The epiphytic cyanophytes Xenococcus kerneri Hansgirg and Chamaesiphon minutus (Rostafinski) Lemmermann were recognized on the cortex of the thalli. Our observations of the determined species are discussed.     

The application and citation of the generic nameParmeliopsis (Lecanorales,Parmeliaceae)

The nomenclatural history of the generic nameParmeliopsis is reviewed. Its correct citation is found to beParmeliopsis (Nyl. exStizenb.)Nyl., dating from 1866, not 1869 as commonly cited, withP. placorodia (Ach.)Nyl. as holotype species. There is consequently no nomenclatural problem to the adoption ofForaminella Fricke Meyer, typified byF. ambigua (Wulfen)Fricke Meyer for theParmeliopsis species with falcate conidia. A synopsis of the nomenclature of the North American and European species of both these genera is included.     

Die Stipeln derIrvingioideae undRecchioideae und ihre systematische Wertung nebst Bemerkungen zur Holzanatomie und Palynologie

TheSimaroubaceae generally have no true stipules. The stipule-like appendages of some genera proved to be pseudo- or metastipules (Weberling & Leenhouts 1965). There seem to be some exceptions, however: the generaCadellia (incl.Guilfoylia) andRecchia on the one hand, and theIrvingioideae on the other. As these taxa, with exception ofRecchia, have simple leaves, there are no indications that their stipule-like appendages might be pseudo- or metastipules. In regard to their position and ontogeny these appendages behave completely like true stipules. Assuming the view ofForman, one could conceive a morphological line from the long, broadly inserted axillary stipules of mostIrvingioideae to the small scaly triangular stipules ofIxonanthoideae. The similarities between the stipules ofIrvingioideae andErythroxylaceae (already emphasized byHallier and others), become even more evident when their ontogeny is investigated. TheIrvingioideae, therefore, might be regarded as a separate family (perhaps with some relation to theErythroxylaceae,Hallier) or as a subfamily ofIxonanthaceae (Forman).—In addition to data on stipules some results on the palynology and shoot anatomy of the generaCadellia (incl.Guilfoylia) andRecchia are reported. Their relationship with theSimaroubaceae also appears doubtful. If they are to be included, they represent a somewhat isolated group near the base of the family which otherwise has lost its stipules.

Herrn Univ.-Prof. Dr.Walter Leinfellner zum 70. Geburtstag gewidmet.     

Subdivision ofPelargonium sect.Cortusina (Geraniaceae)

The sect.Cortusina (Dc.)Harv. s.l. is divided into the sectt.Cortusina (Dc.)Harv. s. str. andReniformia (Knuth)Dreyer, comb. nov.,P. cortusifolium L'Hérit.,P. crassicaule L'Hérit.,P. echinatum Curt.,P. magenteum J. J. A. Van der Walt, andP. sibthorpifolium Harv. remain in the sect.Cortusina s. str., while the speciesP. album J. J. A. Van der Walt,P. dichondrifolium Dc.,P. odoratissimum (L.)L'Hérit.,P. reniforme Curt., andP. sidoides Dc. are removed from the sect.Cortusina s.l. and included in the revised sect.Reniformia. Both sections are well characterized by morphological, anatomical, karyological and palynological features. The chromosomes ofCortusina s. str. are small and based upon x = 11; those ofReniformia are larger and based upon x = 8. The size and surface sculpture of the pollen grains differ markedly between the two sections. Flavones and hydrolysable tannins occur in sect.Reniformia, but are absent in sect.Cortusina s. str. After hydrolysis hydroxybenzoic acids, which are present in large amounts inReniformia, occur only in traces inCortusina. The two sections also occupy distinctly different geographical areas. A close relationship between sect.Reniformia and some species of sect.Ligularia (Sweet)Harv. is indicated by the occurrence of artificial hybrids.     

Karschia destructans: Falsch interpretierte Beziehungen zwischen zwei Flechten

Karschia destructans Tobler is recognized as a synonym ofBuellia schaereri De Not. This species is not a parasitic fungus but a lichen that suffers when growing together withChaenotheca chrysocephala (Ach.)Th. Fr. orChaenotheca phaeocephala (Turn.)Th. Fr. subsp.alpina (Nádv.)Schmidt.

---

Karschia destructans: Falsch interpretierte Beziehungen zwischen zwei Flechten