bluuebunny/crossref_metadata_2025 huggingface dataset:
Some new fungi associated with needle blight of conifers
Authors: Whitney H. S. , Reid J. , Pirozynski K. A.
Published: September 2008

A new phacidiaceous genus, Darkera, is erected to accommodate two species: D. abietis sp. nov. on Abies balsamea (L.) Mill, and A. concolor Lindl. & Gord., and D. parca sp. nov. on Picea glauca (Moench) Voss and P. abies (L.) Karst. Their presumptive conidial states, Tiarosporella abietis sp. nov. and T. parca (Berk. & Br.) comb. nov., respectively, as well as T. pseudotsuga sp. nov. on Pseudotsuga meinziesii (Mirb.) Franco are also described. The relationship of Darkera to other phacidiaceous genera is discussed, with special reference to ascus apices and their reaction to Melzer's reagent.
New dinoflagellate cyst genera from the recent sediments of the Persian Gulf
Authors: Bradford Martin R.
Published: September 2008

Five species of Peridinium-type dinoflagellate cysts are described from sediment samples from the Persian Gulf and the Northern Arabian Sea. A dual classification system, as outlined by Reid (1974) and Sarjeant and Downie (1974), has been followed. These cysts are assignable, using cyst nomenclature, to four new genera: Stelladinium nov.; Leipokatium nov.; Multispinula nov.; and Omanodinium nov. The five new species are S. reidii sp. nov.; L. invisitatum sp. nov.; M. quanta sp. nov.; O. alticinctum sp. nov.; and O. tholus sp. nov. All genera have been attributed to the family Phthanoperidiniaceae Drugg and Loeblich, 1967 emend. nov.
Trypsin inhibitors of fababeans (Vicia faba L. var. minor). 1. Preliminary studies.
Authors: Bhatty R. S.
Published: September 2008

Trypsin-inhibitor activity (TIA) of three cultivars of fababeans was compared with that of soybean. A 50 mM phosphate buffer, pH 7.6, extract of soybean contained 35 times more specific TIA than similarly prepared extracts of fababeans. The fababean trypsin inhibitors (TI), like those of soybean, were highly thermostable. The crude extract possessed 13 to 20% of the original inhibitor activity after heating in a boiling water bath for 60 min. The total TIA was higher in extracts of phosphate (pH 7.6) and of ammonium formate (pH 3.2) than of acetate (pH 4.6). However, the specific TIA of the lower pH extracts was higher as a result of a reduced solubility of the fababean proteins at these pH values.
Succession in deciduous swamp communities of southeastern Michigan formerly dominated by American elm
Authors: Barnes Burton V.
Published: September 2008

Fifty-six permanent sample plots were established in deciduous swamp communities of south-eastern Michigan where Ulmus americana was dominant before introduction of the Dutch elm disease. Plots were also established in old fields where elm seedlings were present. The purpose of the study was to determine the composition of the overstory, understory, and seedling layers in deciduous swamp forests and to provide a base line for determining the fate of young seedling and sapling elms, and the rate and nature of succession in the deciduous swamp communities. The major overstory species in the three swamps studied were Fraxinus nigra, Acer rubrum, and Betula alleghaniensis. These species were also dominant in the understory along with smaller numbers of Carpinus caroliniana, Ulmus americana, Tilia americana, and Fraxinus pennsylvanica. In the next generation the communities will be much as they are today. The overstory dominants are also strongly represented in the seedling layer. Ulmus americana was more abundant in this layer than in the understory. Therefore, Ulmus has not been eliminated from the deciduous swamps but makes up about 10 to 15% of the understory and seedling layers. Old fields and other open upland areas are much more important habitats for regeneration of Ulmus than swamp communities. Indications are that unlike Castanea dentata, Ulmus americana will be perpetuated for generations by seeds from young elm trees; however, the average life span of the species will be drastically reduced.
Postinfectional inhibitors from plants. XXIII. Sesquiterpenoid phytoalexins from fruit capsules of Datura stramonium
Authors: Ward E. W. B. , Unwin C. H. , Rock G. L. , Stoessl A.
Published: September 2008

Datura stramonium fruit capsules inoculated with Monilinia fructicola or several other non-pathogenic fungi produced diffusates inhibitory to M. fructicola in spore germination assays. Detailed analysis of diffusates that are induced by M. fructicola indicated that they were complex and that antifungal activity was widely distributed through a number of column chromatographic fractions. Four compounds were isolated. These were sesquiterpenes, three of which, lubimin, hydroxylubimin, and capsidiol, have been described from other Solanaceae. The fourth, 2,3-dihydroxygermacrene, is a new compound with moderate antifungal activity but which is of especial interest as a possible precursor of several phytoalexins in the Solanaceae.
Studies in the Alismataceae. VI. Specialized rhizome structure of Burnatia enneandra
Authors: Charlton W. A.
Published: September 2008

Rhizomes of the African emergent aquatic Burnatia enneandra M. Mich. possess a layer of tissue superficially resembling a periderm in the position in which an endodermis might be expected. It is suggested that this layer of tissue represents a multiple endodermis. Distinctive idioblasts occur in the outer region of the multiple endodermis. At the end of the growing season soft tissues exterior to the multiple endodermis collapse with the death of the adjacent leaves, leaving behind a fibrous armor of leaf traces and cortical vascular traces. The multiple endodermis, idioblasts, and armor may be of adaptive significance in relation to dry-season dormancy in Burnatia.
Inheritance of virulence of race 370, Melampsora lini
Authors: Statler G. D. , Zimmer D. E.
Published: September 2008

Race 370, Melampsora lini, was selfed and the progeny were tested for virulence on flax cultivars each of which contained a single gene pair for rust resistance. All cultures tested were virulent on flax cultivars with resistance genes L9, M, M1, M2, M4, N1, and P and avirulent on flax cultivars possessing the K, L2, L3, L5, L6, L7, L11, M3, M5, M6, N, N2, P1, P2, P3, and P4 genes for resistance. Segregation for virulence occurred on flax cultivars with the L, L1, L4, and L10 genes. Virulence on cultivars with the L4 and L10 genes was conditioned by single recessive gene pairs. The segregation ratio for virulence on the L1 gene more nearly fit a digenic recessive ratio than a monogenic ratio. Virulence on the cultivar containing the L gene appeared to be conditioned by two recessive gene pairs. Virulence on cultivars with gene L4 was apparently linked with L10, but no linkage was detected between L and L4 or L and L10.
Effect of deficiency of certain micronutrients on the activity of aldolase in radish plants grown in sand culture
Authors: Agarwala S. C. , Bisht S. S. , Sharma C. P. , Afzal A.
Published: September 2008

Deficiencies of each of the micronutrients, iron, zinc, copper, and manganese, decreased the activity of FDP-aldolase (D-fructose-1,6-biphosphate D-glyceraldehyde-3-phosphate-lyase (EC 4.1.2.13)) in leaves of radish (Raphanus sativus L. var. All Season). The depression in the enzyme activity was overcome when deficient plants were supplied normal levels of the micronutrient in short supply. The depression in the enzyme activity could not be attributed to decreased protein levels in the deficient plants. Polyacrylamide gel electrophoresis revealed only one form of FDP-aldolase in All Season radish leaves. Deficiencies of iron, zinc, copper, or manganese resulted in the appearance of two forms of aldolase.
Enzymatic changes and lignification in relation to tracheid differentiation in cultured tuber tissue of Jerusalem artichoke (Helianthus tuberosus)
Authors: Minocha Subhash C. , Halperin Walter
Published: September 2008

In Jerusalem artichoke (Helianthus tuberosus L.) tuber tissue, cultured under optimal conditions (medium containing naphthaleneacetic acid (NAA). benzylamino purine (BAP), and soluble starch), 30–35% of all the cells differentiate into tracheids within 2 weeks. Under slightly different conditions (omission of BAP and starch from the optimal medium or addition of gibberellic acid (GA) or abscisic acid (ABA) to the optimal medium) the same growth rate is obtained with relatively few tracheids (3–5%).Activity of soluble and wall-bound peroxidase is higher in the presence of BAP, irrespective of the number of differentiating cells in the tissue. GA and ABA when added to the medium stimulate peroxidase activity while inhibiting differentiation by almost 90%. The variations in enzyme activity are related neither to the extent of differentiation nor to the rate of lignin biosynthesis in the tissue. Phenylalanine ammonia-lyase (PAL) (EC 4.3.1.5) activity shows some correlation with the amount of differentiation, but this activity is not in direct proportion to the number of differentiating cells under different conditions. Acid phosphatase (EC 3.1.3.2) activity does not change with time after 2 days of culture under any of the conditions. No qualitative differences have been observed in the isozyme patterns of these enzymes with time or in response to hormones.Incorporation of [14C]cinnamic acid and [14C]phenylalanine into cell wall lignin shows an increased rate of lignin biosynthesis in response to BAP. GA and ABA do not significantly affect lignin biosynthesis. Histochemical studies reveal no preferential lignification of differentiating tracheids. Lignin is distributed on parenchymatous as well as differentiated cells.
Study on competition between guaiacol and ascorbic acid in peroxidase reaction and on ion effect by means of absorption spectra
Authors: Demirevska-Kepova Klimentina N. , Bakardjieva Nina T.
Published: September 2008

The absorption spectra of the product of guaiacol oxidation registered in the region of 200–450 nm are characterized by three absorption maxima, 243, 293, and 450–470 nm. The competition between guaiacol and ascorbic acid as hydrogen donors of peroxidase is studied using these spectra. Ascorbic acid inhibits the oxidation of guaiacol and the three absorption maxima change differently. Some possibilities for an interaction between guaiacol and ascorbic acid are discussed; the formation of an intermediary complex compound might be presumed. Calcium, copper, and iron ions that are added in the reaction mixture lead to a modification of the competitive relationship between guaiacol and ascorbic acid.
Merulius: s.s. and s.l., taxonomic disposition and identification of species
Authors: Ginns James H.
Published: September 2008

Twenty-one species are treated in detail. New specific combinations are proposed as Ceraceomerulius albostramineus (Torrend) and its variety flavido-albus (Corner); as Ceraceomyces serpens (Ft.); as Gloeoporus chlorinus (Pat.) and G. subambiguus (P. Henn.); as Leucogyrophana luridochracea (Corner), L. sororia (Burt) and L. montana (Burt); as Meruliopsis ambiguus (Berk.), M. bellus (Berk. & Curtis), M. corium (Fr.), M. hirtellus (Burt), and M. miniatus (Wakef.); and as Radulomyces fuscus (Lloyd). Cultural characters are described in detail for the first time for M. ambiguus, M. hirtellus, Merulius incarnatus Schw., C. borealis (Rom.), C. serpens, and Ceraceomerulius albostramineus. Extensive new synonymy is proposed, which is based on the study of nearly 150 type specimens, and a nomenclator is included which contains over 350 valid combinations in Merulius.
Electron microscopic observations of dividing somatic nuclei in Albugo
Authors: Khan Saeed R.
Published: September 2008

An intranuclear spindle with associated centrioles that are external to the nuclear envelope was present in sections of dividing somatic nuclei in vegetative hyphae, sporangiophores, and sporangia of Albugo sp. The chromatin appeared to be arranged irregularly at preanaphase. Spindle microtubules were dilated at their terminations in kinetochores and poles.
The chemical composition of glochids from Opuntia
Authors: Pritchard Hayden N. , Hall James A.
Published: September 2008

Glochids of two species of cactus were analyzed using infrared spectrophotometry and x-ray diffraction to determine their chemical constituency. The results were compared with calcium oxalate, a known constituent of many plant crystals, and with pure cellulose, the major component of plant cell walls. The analysis showed the glochids to be pure crystalline cellulose.
Etude préliminaire des groupements végétaux caractérisant quelques gîtes larvaires à moustiques dans la région de Trois-Rivières (Québec)
Authors: Lamoureux Gisèle , Lacoursière Estelle
Published: September 2008

The prime objective of a mosquito control that is based on the larvaciding program is the localization of breeding areas. French ecologists were the first to use the vegetation as an indicator of the mosquito breeding sites, and the success that has so far been incurred by this method encouraged its use for the mosquito control program of the 'Basse-Mauricie.' It is therefore with this in view that the authors undertook a study of vegetation groupings that characterized certain breeding sites. Field observations and analysis of phytosociological data permitted, within groupings of different water modes, the disclosure of a certain number of levels that constituted as many types of potential breeding sites.
A mycoparasite on Sclerospora graminicola
Authors: Rao N. N. Raghavendra , Pavgi M. S.
Published: September 2008

Downy mildew or 'green ear' disease of pearl millet (Pennisetum typhoides Stapf and Hubb.) incited by Sclerospora graminicola (Sacc.) Schröter has become a major disease on several improved varieties of the crop plant in India. Fusarium semitectum Berk, and Rav. parasitizes the oospores that develop within the leafy proliferations in the earhead, which consequently makes them unviable. The possibility of using the mycoparasite as a biological control is indicated.
Histological comparison of Cladosporium fulvum race 1 on immune, resistant, and susceptible tomato varieties
Authors: Lazarovits George , Higgins Verna J.
Published: September 2008

Histological comparisons were carried out on three varieties of tomato, Potentate (Cf0), V-121 (Cf3), and Vinequeen (Cf2, Cf4), inoculated with race 1 of Cladosporium fulvum. Examination of leaves harvested at regular intervals indicated that under optimal conditions for disease development, spore germination and penetration were similar on the leaves of the three varieties. The susceptible Potentate became extensively colonized by intercellular mycelium, but relatively little visible damage occurred in the affected cells until sporulation was abundant. In V-121, resistance was expressed by slightly slower growth of the mycelium in the leaf tissue, but colonization was still extensive. Host cell damage became prominent just before the formation of aerial mycelium. Cells in the lesion area on V-121 became necrotic or showed various changes, including reduced starch content in the chloroplasts and the association of extracellular material with the cell walls. Histochemical tests indicated that polyphenols were present in the lesions. The mycelia in V-121 became highly vacuolated and sporulation was absent or greatly reduced. In the highly resistant (immune) Vinequeen variety, fungal development was restricted to a few cells in the mesophyll region. Host cells adjacent to and some distance from the fungus showed extensive deposition of material that was at least partly composed of callose.
Ultrastructure of susceptible, resistant, and immune reactions of tomato to races of Cladosporium fulvum
Authors: Lazarovits George , Higgins Verna J.
Published: September 2008

Ultrastructural examination of the Cladosporium fulvum Cooke – tomato combination was carried out to reveal the nature of the host–parasite interaction. The tomato varieties V-121 (Cf3) and Vinequeen (Cf2, Cf4), inoculated with race 1, served as the resistant hosts. Vinequeen, inoculated with race 12, was used as the susceptible host.Relatively few ultrastructural changes were observed in the susceptible host until sporulation was extensive. In the resistant V-121 host, cytological changes occurred within the lesion area just before aerial mycelia formation (about day 8) and included cytoplasmic disorganization, increased electron density of cytoplasm, limited callose formation, and the association of extracellular material with the cell walls. In the susceptible host, the mycelium was rich in polysaccharide and lipid-like substances, in contrast with the mycelium in V-121 lesions, which was highly vacuolated and had an additional electron-dense layer on the cell wall surface. The reaction of the highly resistant (immune) Vinequeen to race 1 had occurred by day 6 and was characterized by massive callose deposition. Cells within the infection court often had highly vacuolated cytoplasm or were completely decompartmentalized. The hyphae in most instances were probably dead since they either appeared plasmolyzed or were filled with an amorphous material.
The biology of Harveyella mirabilis (Cryptonemiales, Rhodophyceae). III. Spore germination and subsequent development within the host Odonthalia floccosa (Ceramiales, Rhodophyceae)
Authors: Goff Lynda J. , Cole Kathleen
Published: September 2008

A field and laboratory study of the parasitic red alga Harveyella mirabilis has revealed that spore germination and subsequent development of the parasite is dependent on the presence of a suitable host. Initial spore germination occurs in host wounds that are inflicted primarily by grazing isopods and amphipods. Rhizoidal cells intrusively grow into the walls between host cells and establish secondary pit connections with host cells. Subsequent development is characterized by rapid proliferation of the rhizoidal cells within the host, a rupturing of the host's outer wall region, and the final development of a colorless reproductive pustule. Several alternate substrata were used in a study of spore germination requirements, but only those that contained freeze-dried, powdered Odonthalia floccosa and O. washingtoniensis were successful in inducing the germination of Harveyella spores.
Early Tertiary species of Azolla subg. Azolla sect. Kremastospora from western and arctic Canada
Authors: Sweet A. R. , Hills L. V.
Published: September 2008

Species of Azolla subg. Azolla sect. Kremastospora Jain & Hall are described from samples of Early Tertiary age from the Ravenscrag Formation of Saskatchewan, the Paskapoo Formation of Alberta, and the Eureka Sound Formation of Banks Island, District of Franklin.Section Kremastospora is restricted to include only Azolla teschiana Florschütz, A. bulbosa Snead, A. stanleyi Jain & Hall, and A. areolata n. sp. The relative phylogenetic position and stratigraphic significance of these species are discussed.
The annual species of stinging nettle (Hesperocnide and Urtica) in North America
Authors: Woodland D. W. , Bassett I.J. , Crompton C. W.
Published: September 2008

Descriptions (including those of pollen), distributional data, and chromosome counts are given for one species of Hesperocnide and three annual species of Urtica (stinging nettles) in North America north of Mexico: Hesperocnide tenella, Urtica chamaedryoides, U. gracilenta, and U. urens. Hesperocnide tenella has a chromosome number of 2n = 24 while all three Urtica spp. have the same chromosome number of 2n = 26. All reported chromosome numbers are new except the one for U. urens. A key which separates the taxa that are studied is provided and synonyms that are applied to the species are discussed.
Scanning ultrastructural ontogeny of eugymnohymenial apothecia in the operculate Discomycetes Ascodesmis nigricans and A. sphaerospora
Authors: O'Donnell K. L. , Hooper G. R. , Fields W. G.
Published: September 2008

The developmental ontogeny of eugymnohymenial apothecia in Ascodesmis nigricans van Tieghem and A. sphaerospora Obrist, homothallic operculate Discomycetes (Pezizales, Pyronemataceae), was investigated from initiation of the T-shaped gametangial initials through spore discharge. Branching of these T-shaped side branches gave rise to gametangia that paired and coiled helically. Paraphyses proliferated from the base of the rosette of gametangia and enveloped the coils, which appeared to undergo plasmogamy at their apices. Although a loose peridium of paraphyses was formed, a true excipulum was absent. Displacement of the opercula on the positively phototropic asci was towards the more strongly illuminated side.
Development of dichotomous branching and axillary buds in Strelitzia (Monocotyledoneae)
Authors: Fisher Jack B.
Published: September 2008

The morphology and development of branches and inflorescence buds in two species of Strelitzia are described and illustrated. Axillary buds develop similarly in each species, producing both inflorescences and suckers in the caulescent S. nicolai and only inflorescences in the acaulescent S. reginae. Bud initiation occurs in the axil of the first or second leaf primordium. A well developed shell zone is present. Branching in S. reginae occurs by the division of the apical dome above the first leaf primordium and is considered a true dichotomy. Fasciation occurs in 37% of leaves enclosing the two new shoots in S. reginae. It is concluded that dichotomous branching should not be interpreted as a phylogenetically primitive character in the monocotyledons.
Developmental studies on Euphorbia esula: seasonal variation in the apices of long roots
Authors: Raju M. V. S. , Steeves T. A. , Maze J.
Published: September 2008

Long-root apices of Euphorbia esula L. were supplied with [3H]thymidine in the field on 11 occasions during the growing season. Autoradiographs of the root apices showed that the characteristic quiescent centre of long roots was absent in a large percentage of the roots in the early part of the growing season. It is suggested that the cells of the quiescent centre play an important role in the seasonal reactivation of the perennial roots of this species.
Blastocladiopsis elegans, a new member of the Blastocladiales
Authors: Robertson Jack A.
Published: September 2008

A new water mold in the Blastocladiales has been isolated and cultivated and is now described. It is placed in the genus Blastocladiopsis along with the previously known B. parva. The most striking feature of the new organism is the prominent reticulate ornamentation of the resistant sporangia. This same feature was illustrated in a partial description of a water mold isolated in 1936 by Sörgel, and it is thought that Sörgel's species might be the same as the one described here. Zoospores from both zoosporangia and resistant sporangia give rise to the same type of thallus; therefore, the organism appears to lack sexuality.
In vitro plantlet formation from flower petal explants of Hemerocallis cv. Chipper Cherry
Authors: Heuser Charles W. , Apps Darrel A.
Published: September 2008

Plantlet regeneration has been induced from callus tissue cultures obtained from petal parts of Hemerocallis cv. Chipper Cherry. Callus cultures capable of regenerating whole plantlets were established on the agar-solidified Murashige and Skoog's medium supplemented with (2,4-dichlorophenoxy)acetic acid (2,4-D) (1.0 mg/litre) + kinetin (1.0 mg/litre). The callus formed was dense, yellowish-green in color, and had what appeared to be meristematic protuberances. Shoots and roots developed when the callus was subcultured on a medium lacking 2,4-D.
Ecological studies in the boreal spruce–fir forests of the North American taiga. II. Analysis of the bryophyte flora
Authors: Roi George H. La , Stringer Muriel H. L.
Published: September 2008

The bryoflora of 34 white spruce – fir and 26 black spruce stands in the boreal forest subzone consisted of 100 mosses and 33 liverworts. Short turfs, smooth mats, threaded mats, and tall erect turfs were the most species-rich growth-forms; wefts were cover dominants. White spruce – fir stands had more species but lower cover than black spruce. The liverwort:moss species ratio in white spruce – fir increased with precipitation. Based on bryoflora and geography, stands were classified as follows: white spruce – fir, Hylocomium splendens – Pleurozium schreberi order (= three associations of western Ceratodon purpureus – Pylaisiella polyantha alliance and two associations of eastern Rhynchostegium serrulatum – Tetraphis pellucida alliance); black spruce, Pleurozium schreberi – Hylocomium splendens order (= three associations of western Drepanocladus uncinatus – Brachythecium salebrosum alliance and two associations of eastern Sphagnum – Hypnum pallescens alliance). Of the 32 most important species, 16 'preferred' wood, 7 needle litter, 6 mineral soil, and 3 bark. The ground cover hierarchy in white spruce – fir was weft mosses > detritus [Formula: see text] needles > wood > other bryophytes > lichens > bark > soil; in black spruce, wood and other bryophytes were reversed. Higher species richness of white spruce – fir stands was ascribed to higher productivity and greater age, which gives a greater diversity and quantity of woody substrates for microsuccessional species. Shortage of suitable substrate and competition from weft mosses may explain the consistently low abundance of most other bryophytes in the two community types.
Effect of light and temperature on number and length of Helminthosporium gramineum conidia produced in culture
Authors: Teviotdale Beth L. , Hall Dennis H.
Published: September 2008

Helminthosporium gramineum sporulated in culture when grown at 26 °C on barley leaf pieces on 1.5% water agar and then exposed to fluorescent light at intensities of 0.0045, 0.0076, and 0.0338 cal cm−1 s−2 (1 cal = 4.184 J) followed by incubation at 6, 12, 18, or 24 °C. The number of conidia produced increased with time of irradiation and time at low temperature. Length of conidia at maturity was increased by prolonged exposure to low temperature and the greatest mean length of conidia occurred after 16 h at 12 °C. A lapse of time between irradiation and exposure to reduced temperature resulted in sterile conidiophores. Sporulation occurred in continuous light and constant temperatures from 12 to 18 °C, but a reduction in temperature after irradiation at 24 °C or above was necessary for formation of conidia. Conidium formation was inhibited by constant temperatures above 21 °C but not by light at any temperature.
The type locality of Polygonum plumosum
Authors: Murray David F.
Published: September 2008

Inadvertently switched labels on specimens at the New York Botanical Garden led J. K. Small to cite the wrong locality for the specimen he selected as the holotype for Polygonum plumosum. The correct locality is St. Matthew Island, Alaska, not St. Paul Island.
Characterization of soluble nucleohistone and histone from cotyledons of germinating seeds of Pinus pinea
Authors: Berkofsky J. , Roy R. M.
Published: September 2008

Soluble nucleohistone and histones have been isolated from cotyledons of Pinus pinea; this is the first such isolation from any gymnosperm tissue. The nucleohistone isolated was similar in composition and physical characteristics to that of chromatin reported for comparable angiosperm tissues at similar stages of growth. Histones, purified by gel electrophoresis, possessed eight subfractions which are tentatively identified as follows in order of increasing electrophoretic mobility: very lysine-rich F1 (fractions 1–4), arginine-rich F3 (fraction 5), arginine-rich F2a2 (fraction 6) and F2b (fraction 7), as well as moderately arginine-rich F2a1 (fraction 8). Nucleohistone from days 15 to 22 of germination, a period of cell elongation in cotyledons, possessed greater amounts of histone, acidic protein, and RNA relative to DNA than day-14 'mitotically active' nucleohistone. Histone acetylation from sodium acetate, methylation from s-adenosyl-L-methionine, and phosphorylation from inorganic phosphate proceeded at low rates in isolated nuclei. Phosphorylation from [32P]ATP occurred to a greater extent; very lysine-rich F1 and arginine-rich F3 histones were phosphorylated to the greatest degree while F2a1 was phosphorylated least.
Scanning electron microscopy of early sporeling ontogeny of Chondrus crispus
Authors: Chen Lawrence C.-M. , Taylor A. R. A.
Published: September 2008

Early ontogeny of sporelings of Chondrus crispus Stackhouse has been examined using scanning electron microscopy. The most significant feature is the formation of a blanket-like extracellular sheath preceding internal cell differentiation. It is suggested that this sheath may play an important role in determining the type of sporeling development, discoid or filamentous, and the coalescence of adjacent sporelings.
Dendrogram topology: capacity and retrieval
Authors: Phipps J. B.
Published: September 2008

This paper defines the 'capacity' of dichotomous dendrograms of a given order as the total number of topologically different cases. By using a combinatorial approach based on the number of possible cases for each part of a root dichotomy and extending this through the dendrogram, the capacity for each order may be calculated. By saving a 'principal divisions table' accumulated during the calculation of the capacity, sufficient information is retained for a recursive search through the table that will generate a 'D-array' uniquely describing the topology of any specified dendrogram. This search procedure is called 'dendrogram retrieval.' Of general interest will be the large capacity (e.g. about 1011) for even quite low (e.g. D35) orders of dendrogram.
The numbers of classifications
Authors: Phipps J. B.
Published: September 2008

This paper demonstrates how to establish the number of pair-group classifications for any given order that may differ in both topology and arrangement of identifiers. At N = 50 there are about 1080 different classifications, a figure of the order of the number of electrons in the universe. The large number of possible classifications of even quite low orders of entities underlines the problem of taxonomists in selecting any best classification.
Ultrastructural studies on germinating ascospores of Daldinia concentrica
Authors: Beckett A.
Published: September 2008

Ascospore germination in Daldinia concentrica has been studied using light and electron microscope techniques. Preliminary observations indicated that lipid globules were utilized during early stages of germination. Apical wall vesicles were localized during germ tube initiation and were involved in the differentiation of a filamentous germ tube. Wall synthesis occurred during germination and resulted in a new wall layer, which was different in ultratexture to the spore wall and which formed the germ tube wall. Possible implications of the concept of spore wall and vegetative wall types during germination are discussed.
The uptake of nickel by Umbilicaria muhlenbergii: a physicochemical process
Authors: Nieboer E. , Puckett K. J. , Grace B.
Published: September 2008

The uptake of nickel by U. muhlenbergii (Ach.)Tuck. has been investigated. The data suggest that the uptake is physicochemical in nature. Metabolic inhibitors caused no significant decrease in nickel uptake. Dead thalli accumulated the metal to a slightly greater extent than live thalli. Nickel uptake was similar under aerobic and anaerobic conditions. Uptake was pH dependent and increased with temperature. The development of a model for nickel uptake by U. muhlenbergii based on thermodynamically rigorous expressions is described in this paper.
The mentor pollen phenomenon in black cottonwood
Authors: Stettler R. F. , Guries R. P.
Published: September 2008

Black cottonwood (Populus trichocarpa T. & G. ex Hook.) is in the Tacamahaca section of poplars and cannot normally be crossed with members of the Leuce section. Earlier studies had shown that such crosses succeed if black cottonwood is pollinated with a mixture of pollen, combining foreign with irradiated pollen of the maternal species. This ‘mentor’ pollen phenomenon was further studied during 1970–1975. Black cottonwood pollen, irradiated with a 60Co source at 0.4, 1, 10, and 100 kR, was indistinguishable from normal pollen in germination and tube growth in situ and promoted fruit development on cut branches but failed to set seed at the highest dosage. Pollen from P. alba var. bolleana and P. tremuloides (both Leuce) showed normal germination and stigma penetration but delayed or slowed tube growth and led to premature catkin abscission. Mixes of 20-, 40-, and 80-kR-irradiated mentor pollen mixed with foreign pollen resulted in good fruit development but little seed set, probably because the mentor pollen successfully competed for available ovules without producing embryos. Hybrid seedlings were weak and susceptible to early mortality. Incompatibility in these crosses is manifest inside the stigmatic and stylar tissue and resembles gametophytic self-incompatibility. The irradiated mentor pollen in black cottonwood seems to facilitate hybridization indirectly through the promotion of fruit development rather than as a provider of recognition substances to the associated foreign pollen, as described for other poplars.
Parkerella, a new genus of Coronophorales
Authors: Funk A.
Published: September 2008

A new genus of ascomycetes, Parkerella, is erected for a fungus found on cork bark of aspen (Popttlus tremuloides Michx.) in British Columbia. It is shown to have affinities to the genus Thaxteria of the Coronophorales and is assigned to this order.
Rates of non-suberized impervious tissue development after wounding at different times of the year in three conifer species
Authors: Mullick D. B. , Jensen G. D.
Published: September 2008

Rates of development of a non-suberized impervious tissue (NIT), which is a prerequisite to necrophylactic periderm formation, vary on the same tree with the changing environment at different times of the year. In Abies amabilis (Dougl.) Forbes, rates varied from 14 days in June, slowing gradually to 35 days in fall, virtually ceasing in winter, and resuming slowly (70 days) in spring. This cyclical pattern in rates of NIT formation was also found in Tsuga heterophylla (Raf.) Sarg. and Thuja plicata Donn. Fluctuations in the environment occasioned by year-to-year within-season variations appear to affect the physiology of NIT formation; in July, NIT developed after 21 days in 1968 and after 16 days in 1969, on the same A. amabilis. Preliminary observations indicate presence of intraspecific variations in the rates. Rates were consistently faster on the resistant than on the susceptible A. amabilis heavily infested with balsam woolly aphid, Adelges piceae Ratz. Possible causes of these variations and implications of the findings, in relation to process of NIT formation as a basic physiological host component in pathogenic interactions of bark, are discussed.
Growth of filamentous marine fungi in a continuous culture system
Authors: Churchland L. M. , McClaren M.
Published: September 2008

A continuous culture system has been designed for the cultivation of certain species of marine fungi. Growth in this apparatus was compared with growth in batch culture. Growth of the three marine species tested (Zalerion maritimum, Humicola alopallonella, and Monodictys pelagica) was significantly higher in continuous culture than in batch culture.Growth of two isolates of Z. maritimum was compared on three inorganic nitrogen sources and one organic nitrogen source. Growth of the fungus in the continuous system differed both qualitatively and quantitatively from that in batch culture. Both isolates showed greater growth on the organic nitrogen source in the closed system. In the continuous system, growth was equivalent on all nitrogen sources.
Host–parasite interfaces in a resistant and a susceptible cultivar of Solanum tuberosum inoculated with Phytophthora infestans: tuber tissue
Authors: Hohl Hans R. , Stössel Peter
Published: September 2008

Host–parasite interfaces in potato tubers (Solanum tuberosum) of a resistant (Eba) and a susceptible (Bintje) cultivar inoculated with Phytophthora infestans were studied with transmission electron microscopy. In the resistant host the fungal haustoria are typically small and surrounded by an electron-dense extrahaustorial matrix and electron-transparent wall appositions, normally in form of complete encasements. Wall appositions are generally lacking in the susceptible host or occasionally are found as a collar at the base of the rather large haustorium, which is surround by a well developed extrahaustorial matrix. Since wall appositions probably contain largely a callose-like material, potential roles of fungal glucanases in this host–parasite system are discussed.
Effects of salinity changes on growth and metabolism of the marine centric diatom Cyclotella cryptica
Authors: Liu Ming Sai , Hellebust Johan A.
Published: September 2008

Cyclotella cryptica grows well over a wide range of salinities and can therefore be considered a euryhaline species. The content of chlorophylls a and c of this diatom varies little in the medium salinity range but declines markedly in long-term experiments at both the high and low salinity extremes.Transfer of cells from low to high salinities causes a stress condition evidenced by a lag phase in growth, probably resulting from temporary plasmolysis and decreased photosynthetic and protein synthesis capacities. These stress conditions are also associated with rapid accumulation of free amino acids, including proline, either from photoassimilated carbon or from heterotrophic assimilation of glucose in the dark. Transfer of cells back to low salinity conditions results in rapid decreases in these amino acids.
Effects of salinity and osmolarity of the medium on amino acid metabolism in Cyclotella cryptica
Authors: Liu Ming Sai , Hellebust Johan A.
Published: September 2008

The amino acid metabolism of Cyclotella cryptica is strongly influenced by changes in salinity of the medium. A sudden increase in salinity (water stress) reduces the total uptake of amino acids by the cells and also their assimilation into proteins. Under water-stress conditions, proline is readily synthesized from glutamate, arginine, and ornithine. and proline synthesized under these conditions turns over very slowly and accumulates.Increases in osmolarity of the medium, whether caused by salts, mannitol, or sucrose (but not by glycerol), is followed immediately by rapid synthesis of proline. Proteolysis is not observed under water-stress conditions. The high level of proline accumulated under these conditions is rapidly reduced when the cells are transferred back to low osmolarity media. The loss of 14C from proline is accompanied by rapid incorporation into proteins and also conversion of proline into other cell constituents.The proline level is relatively low in high-salinity-adapted cells, and proline turns over rapidly in such cells. This indicated that the accumulation of proline occurs mainly in response to abrupt changes of intracellular ionic strength during adaptation to increased salinities. Additions of salts and organic substances to cell suspensions in low-salinity media cause plasmolysis followed by rapid deplasmolysis. However, when cells are transferred to high-osmolarity solutions of single salts or organic substances, deplasmolysis is only observed in media containing KCl or glycerol. Increases of external osmolarity cause increases in concentrations of intracellular potassium and free amino acids.
Regulation of proline metabolism in the marine centric diatom Cyclotella cryptica
Authors: Liu Ming Sai , Hellebust Johan A.
Published: September 2008

Proline synthesis from both glutamate and arginine is much lower in the dark than in the light. The reduction of proline synthesis in the dark is more pronounced from glutamate than from arginine in starved cells under water-stress conditions. Addition of glucose to such cells stimulates the synthesis of proline from both amino acids. There is no appreciable effect of light on the catabolism of proline. Light seems to be particularly required for the formation of proline from glutamate or arginine in C. cryptica. Other pathways of amino acid metabolism are less, and differently, affected by light conditions. The synthesis of asparagine is stimulated by starving cells in the absence of light, while the synthesis of macromolecules from glutamate is strongly depressed under these conditions. The capacity for amino acid uptake is strongly stimulated by dark incubation in the absence of glucose (energy deficiency).Feedback regulation of proline biosynthesis is very effective in normal cells with either amino acids or glucose as precursors. However, such regulation of proline synthesis is considerably decreased when the cells are subject to water stress. Glutamate strongly inhibits arginine conversion to glutamate and aspartate, and to a smaller degree its conversion to proline.Several enzymes involved in proline synthesis have been examined. Arginase (EC 3.5.3.1) and Δ1-pyrroline-5-carboxylate reductase (EC 1.5.1.2) occur in cell free extracts of C. cryptica. There is no significant difference in the enzymatic activities from normal and water-stressed cells. These enzymes are not inhibited by proline. Glutamate kinase and ornithine transaminase (EC 2.6.1.13) were not detected in cell-free extracts, although results from radiotracer experiments imply the presence of both of these enzymes at high levels in the cells.
Occurrence and nutritive quality of lowbush cranberry on the Kenai Peninsula, Alaska
Authors: Oldemeyer John L. , Seemel Robert K.
Published: September 2008

The quantity and quality of lowbush cranberry (Vaccinium vitis-idaea L.) were studied on the Kenai National Moose Range, Alaska. Its frequency of occurrence and canopy coverage were highest in mature hardwood stands, intermediate in postburn regrowth stands of paper birch (Betula papyrifera) and spruce (Picea mariana and P. glauca), and lowest in mature spruce–hardwood stands. Its biomass, which was strongly correlated with canopy coverage (r = 0.976), was estimated as 1000–3000 kg per hectare in this area. In vitro dry matter disappearance (with moose rumen inocula) ranged from 41.2% in winter to 50.8% in summer, but the protein content (5.4–5.7%) did not change throughout the year. In winter, cell walls, acid-detergent fiber, and lignin increased slightly, while the concentration of eight detectable minerals decreased sharply.
Notes on some parasitic fungi from southern British Columbia, southwest Alberta, and adjacent United States
Authors: Savile D. B.O.
Published: September 2008

New host and geographic records are given for various fungi. The following are included: Uromyces peckianus ssp. verruculosus ssp. nov. on Distichlis spicata. Vancouver Island; Exobasidium phyllodoces comb. nov. on Phylloduce empetriformis, B.C. and Wash.; Puccinia phaceliae, new host and geographic records for B.C., Alta., Wash.; and P. ornatula on Viola glabella, Olympic Mts., Wash. Rediscovery of P. ornatula at Glacier, B.C.. elucidates its ecology. Puccinia praegracilis var. praegracilis has been rediscovered at the type locality.
A new Clitocybe from the Alaskan Arctic
Authors: Laursen Gary A. , Miller Jr. Orson K. , Bigelow Howard E.
Published: September 2008

A new species of Clitocybe is described from the Alaskan Arctic. This agaric grows on low-center polygon rims, high-center polygons, and on beach ridges. Drawings of microscopic features and macrophotographs are included.
Mitosis and cell division in some cereal rust fungi. II. The processes of mitosis and cytokinesis
Authors: Harder D. E.
Published: September 2008

Before mitosis in intercellular Puccinia graminis f. sp. avenae, P. coronata f. sp. avenue, and axenic P. graminis f. sp. tritici and P. coronata, the nuclei were reduced in size by nucleolar extrusion and (or) partitioning of variable portions of the nucleus. Also there was increased vesiculation in the cytoplasm with a corresponding increase in lipid and carbohydrate storage material.The mitotic spindle first formed in one corner of the nucleus, then elongated until the spindle poles were oriented at either end of the nucleus. During the intermediate stages of mitosis the chromatin was arranged around the periphery of the spindle, which consisted mostly of chromosomal fibres. In the later stages the nucleus elongated and became dumbbell-shaped, with long straight fibres passing through the nucleus from pole to pole. The end of mitosis was marked by the chromatin assuming a ‘two-track’ configuration at the poles on either side of the intranuclear fibres and by the breakdown of the nuclear envelope in the constricted region of the dumbbell-shaped nucleus.After the daughter nuclei had separated, they migrated into new hyphal branches and septum synthesis was subsequently initiated. The septa grew by centripetal invagination in both the intercellular and the axenic hyphal states. There were often accumulations of mitochondria in the region of septal growth. Mature septa of intercellular P. coronata and axenic P. coronata and P. graminis tritici were typical of those found elsewhere in the rust fungi.
Electron microscopy of urediospore formation in Puccinia coronata avenae and P. graminis avenae
Authors: Harder D. E.
Published: September 2008

Electron microscopy revealed that the sporogenous cells in urediosori of Puccinia coronata avenae and P. graminis avenae were enlarged at one end, and the cytoplasm was dense, vacuolated, and showed an early accumulation of lipid droplets. Urediospore formation was initiated by the outgrowth of a spore bud from the enlarged end of a sporogenous cell. A nuclear division occurred in the spore bud, the spore bud then grew to form the urediospore initial, and a septum formed to delineate the urediospore initial from the sporogenous cell. A further nuclear division occurred in the urediospore initial followed by septation to form the pedicel and spore cell. The urediospores rapidly grew to full size and further differentiation was marked by increased density of the cytoplasm, disappearance of vacuoles, increased lipid droplet accumulation, thickening of the spore wall, and spine formation. Nucleoli were not found in nuclei of mature urediospores. Possible paraphysis cells were intermixed with urediospores near the margins of urediosori of P. coronata. These cells were characterized by small nuclei which contained densely staining patches, a fine membranous network throughout the cytoplasm, and numerous cytoplasmic inclusions of variable morphology.
Effects of 15% CO2 on the susceptibility of Phaseolus vulgaris to Colletotrichum lindemuthianum
Authors: Arnold Robert M. , Rahe James E.
Published: September 2008

Changes in the nature of the interaction between Phaseolus vulgaris and a compatible race of Colletotrichum lindemuthianum were obtained by treatment of inoculated plants with 15% CO2 in air. A shift towards resistance, manifested by the appearance of flecks similar to those which develop in a natural incompatible interaction, occurred on plants placed in CO2 during the early stages of fungal penetration and maintained there until symptoms appeared. With such treatment, almost complete reversal of the interaction was obtained when the density of infection sites was sufficiently great to give coalescent necrosis in controls that were not CO2-treated. A lesser effect occurred when CO2 treatment was begun at later stages of development of the interaction. Histological studies showed that the rate of colonization of host cells by hyphae of the fungus was reduced in the presence of 15% CO2. These results indicate that CO2 may change the nature of the interaction to one of resistance by selectively slowing down the growth of the fungus while allowing a defense response of the host to develop to a degree where it can prevent further spread of fungal hyphae.
Embryogenesis and formation of tetraploid and hexaploid plants from carrot protoplasts
Authors: Dudits D. , Kao K. N. , Constabel F. , Gamborg O. L.
Published: September 2008

Carrot cells cultured in vitro as well as protoplasts isolated from these cells formed embryos and grew into mature plants. Treatment of the protoplasts with polyethylene glycol (PEG) did not interfere with the capacity of this material to multiply and differentiate. Plants grown from PEG-treated protoplasts exhibited a higher frequency of tetraploids than those grown from untreated protoplasts and from the original cells.