bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemotaxonomic studies in the Saxifragaceae s.l. 1. The flavonoids of Tellima grandiflora
Authors: Collins F. W. , Bohm B. A.
Published: September 2008

Twenty-seven flavonols were isolated from entire plants of Tellima grandiflora (Pursh) Dougl. Kaempferol and quercetin occurred as their 3-glucosides, 3-galactosides, 3-arabinosides, 3-rutinosides, and 4′-glucosides. Myricetin occurred as the 3-glucoside and 3-galactoside. Twelve acylated derivatives based upon the 3-glucosides and 3-galactosides of the three flavonols were isolated but not completely characterized. The flavonoid glycoside chemistry of Saxifragaceae s.l. was reviewed.
Chromosome numbers, meiotic behavior, and notes on tropical American grasses (Gramineae)
Authors: Davidse Gerrit , Pohl Richard W.
Published: September 2008

Chromosome numbers and meiotic behavior are reported for 126 collections of grasses representing 50 genera and 111 species. First counts are given for the genera Leptothrium, n = 10, and Cryptochloa, 2n = 22 (somatic count). First chromosome counts are given for the following 25 species: Aristida recurvata, n = 11; Axonopus laxus, n = 20; Chloris mollis, n = 20; Chusquea longifolia, n = 20; Cryptochloa concinna, 2n = 22; Digitaria abyssinica, n = 18; Eragrostis airoides, n = 36; E. guianensis, n = 10; Eriochloa boxiana, n = 18; Gymnopogon foliosus, n = 10; Leptothrium rigidum, n = 10; Luziola pittieri, n = 12; L. spruceana, n = 24; Otachyrium inaequale, n = 10; Panicum cayennense, n = 27; P. chloroticiun, n = 18; P. schiffneri, n = 18; Pappophorum pappiferum, n = 30; Paspalum apiculatum, n = 10; P. arundinaceum, n = 30; P. contractum, n = 9; P. coryphaeum, n = 30; P. trachycoleon, n = 20; Setaria barbata, n = 27; and Trisetum foliosum, n = 28. Counts that differ from previously reported counts are given for the following 15 species: Axonopus chrysoblepharis, n = 10; Cenchrus brownii, n = 34; Digitaria horizontalis, n = 9, 27; Echinolaena gracilis, n = 10; Euclasta condylotricha, n = 10; Hyperthelia dissoluta, n = ca. 30; Ischaemum guianense, n = 18; Microchloa indica, n = 12; Paspalum candidum, n = 10; P. melanospermum, n = 20; P. prostratum, n = 10; Rhytachne rottboellioides, n = 16; Setaria paniculifera, n = 16; Sorghastrum incompletum, n = 20; and Thrasya petrosa, n = 30. Changes in nomenclature are indicated for Digitaria species whose chromosome numbers were reported in our earlier publications.
Nova Scotian fungi. New species and records of amanitas for the province
Authors: Stewart Harold L. , Grund Darryl W.
Published: September 2008

Eight species of Amanita collected in Nova Scotia are compared macroscopically and microscopically with previously published descriptions and some new data are given. Of these eight, five species and one variety are recorded from the province for the first time, and two (Amanita macrospora and A. solaniolens) are described as new species.
Orphanomyces, a new genus of cypericolous smuts
Authors: Savile D. B. O.
Published: September 2008

An arctic–alpine Carex smut, described by Rostrup as Tilletia arctica and later assigned to Cintractia and Ustilago, has completely external sori and has no relationship to any of these genera. It is assigned to Orphanomyces gen. nov. (Ustilaginaceae). A second species, O. vankyi sp. nov., is described from the mountains of Transylvania on Carex acutiformis.
Embryology of Agrostis interrupta (Gramineae)
Authors: Maze Jack , Bohm Lesley R.
Published: September 2008

Because of the characteristic morphology of the grass ovule, it is proposed that the end of the ovule opposite the micropyle be referred to as the basal end rather than the chalazal end. The ovule is hemianatropous, bitegmetic, and tenuinucellate. Both integuments are mostly two cells thick and exhibit some stretching of individual cells along the side of the ovule. This stretching is concomitant with increase in ovule length. The inner integument forms the micropyle and persists longer than the outer integument. Elimination of the outer integument is a result of stretching. The fruit wall is unlignified as a result of the transfer of the function of protection to the lemma. As evidenced by patterns of cell elongation, fruit elongation occurs first along the sides. There are few periclinal divisions in the nucellar protoderm, these occurring near the point of attachment of the ovule. Megasporogenesis and megagametogenesis are normal. Callose is associated with megaspore formation. The mature orientation of the megagametophyte, relative to the placenta, is obtained at approximately the two-nucleate state of development. Antipodal proliferation occurs before fertilization. After fertilization, large multinucleolate nuclei and multinucleate cells are seen in the antipodals. The cytological abnormalities seen in the antipodals may be associated with hormonal imbalance. The synergid, which will be penetrated by the pollen tube, develops a filiform apparatus before the other synergid. The pollen tube deposits sperm cells in a degenerated synergid. Endosperm is free nuclear and walls form first around the embryo. Starch appears at later developmental stages in the endosperm. When cellular, the endosperm grows by cell division at its periphery. There are two morphological axes within the grass ovule, that between the egg apparatus and the antipodals and that between the micropyle and basal end. In Agrostis interrupta, these two axes form a wide angle. Embryologically, A. interrupta is more similar to Avena. There are also embryological features that seem to characterize the Aveneae and Stipeae. Three general types of embryological similarities and differences can be discerned in the grasses, as well as in other plants: (1) similarities and differences that reflect relationships; (2) similarities of rare occurrence with no obvious taxonomic significance; (3) rare differences of no obvious taxonomic significance.
Modern pollen assemblages near the arctic tree line, Mackenzie Delta region, Northwest Territories
Authors: Ritchie J. C.
Published: September 2008

Samples of surficial lake sediment and of moss polsters from 39 sites in the forest-tundra transitional area immediately east of the Mackenzie Delta, Northwest Territories, were investigated palynologically. Lake sediment samples within the forest and tundra regional vegetation zones are constant in pollen frequencies, but forest–tundra sites are very variable. Forest site spectra are composed of just over 50% arboreal types (spruce, 25–30%; birch, 30%), with 30–40% alder pollen. Tundra spectra have 60–70% non-arboreal types, and 10–15% each of alder and spruce. Forest–tundra values are variable, generally lying between the forest and tundra proportions. Polster samples show as much variability within as between regions, because of local effects. Polster samples indicate local community composition with the regional pollen rain variably masked by the local elements.
Vegetational heterogeneity during a primary sand dune succession
Authors: Morrison R. G. , Yarranton G. A.
Published: September 2008

The Grand Bend succession can be divided into three periods: a colonizing stage, up to 1600 years; a transition period from 1600 to 2900 years; and a persistent stage from 2900 to at least 4800 years. The colonizing stage is dominated by grasses, Juniperus spp. and Quercus prinoides. Transition begins when persistent species invade at certain points; the earliest species are usually Quercus velutina × rubra, Rhus aromatica, and Prunus virginiana. During the transitional period the patches of persistent vegetation grow until they coalesce. This marks the inception of the persistent stage during which the vegetation cover is predominantly oak–pine forest. Hence the path of succession does not differ from point to point but the rate of succession does. It is argued that the existence of distinct successional stages and the mode of transition between them support the organismal concept of vegetation.
Notes on Hyphomycetes. V. A new thermophilic species of Acremonium
Authors: Morgan-Jones G.
Published: September 2008

A new species of Acremonium Link ex Fr., A. alabamensis, isolated from needles of Pinus taeda L., is described and illustrated. It is compared with A. thermophilum W. Gams and Lacey.
Growth rates and productivity of Cladonia arbuscula and Cladonia impexa on the Sands of Forvie, Scotland
Authors: Prince C. R.
Published: September 2008

Cladonia arbuscula (Walk.) Rabenh. and C. impexa Harm, were found to have annual growth rates of 4.6 mm and 5.1 mm respectively. These species together contribute about 470 kg/ha per annum of dry matter in a Calluna–Empetrum dry heath community.
A comparative light and electron microscopic study of microsporogenesis in male-fertile and cytoplasmic male-sterile pepper (Capsicum annuum)
Authors: Horner Jr. Harry T. , Rogers Milton A.
Published: September 2008

In the male-fertile line of pepper, microsporogenesis and pollen development are normal. During meiosis, the meiocytes become encased in callose and a locular cavity forms. A rudimentary pollen wall, preceded by primexine deposition, is formed at the tetrad stage around the microspores before their release from the callose. The tapetum remains peripheral in the locule until the vacuolate pollen stage when it disappears. The sporogenous cells of the cytoplasmic male-sterile line complete meiosis, and the callose-encased microspores also deposit a primexine. Further development of the microspores is arrested. Before and during meiosis the tapetal cells become highly vacuolate and remain appressed to the meiocytes; a locular cavity is not formed. After primexine deposition, the tetrads of microspores, which are still encased in callose, seem to collapse as they are encroached upon by the vacuolate tapetum. After abortion of the microspores the outer tapetal layer degenerates, followed by the inner tapetal layer. The aborted mass late in anther development consists of crushed microspore tetrads, primary walls of the sporogenous cells and tapetum, callose, and the collapsed tapetum. The manner of abortion in pepper is compared with previously described mechanisms.
The fine structure of conidium initiation in Ulocladium atrum
Authors: Carroll Fanny E. , Carroll George C.
Published: September 2008

Synchronous conidiation was induced in pure cultures of Ulocladium atrum by removal of a dialysis membrane overlay beneath which vegetative mycelium had been allowed to grow for 24 h on a solid nutrient agar medium. Samples taken [Formula: see text] and 6 h after the induction of sporulation contained numerous conidiophores with conidial initials in the very earliest stages of formation. Examination of sections of such conidiophores with the electron microscope revealed no suggestion of a discontinuity in the wall between the conidiophore and the conidial initial. We conclude that conidiation in Ulocladium atrum is holoblastic.
Notes on the biology of some native orchids of Thunder Bay, their endophytes and symbionts
Authors: Harvais Gaëtan
Published: September 2008

Field studies were made of eight terrestrial orchid species of the Thunder Bay region during their active growing period. In four of them roots were examined for infection, then isolation and identification of endophytes attempted.Seeds were collected from all species and, along with those of two alien ones, were grown on various media in axenic culture. Their germination and development were studied and described.Seeds were also tested in dixenic cultures with locally isolated endophytes and four fungi known to be good symbionts with other orchids. The nature of infection was finally assessed and discussed.In the field the roots of mature plants of the orchid species differed in their degree of infection and reaction to their endophytes. Only two species of Rhizoctonia were isolated. These are described.In axenic culture, germination of some species was affected by the organic (and inorganic) components of the media, in others it was not. For growth they all responded differently to such components, but most were intolerant of casamino acids, yeast extract, and potato extract. Generally there seemed to be a direct correlation between percentage of germination and amounts of subsequent growth, but a less defined one with the number of cells per seed.In dixenic cultures the orchids responded differently also to the fungi. Their reaction to infection had no relation to their ability to germinate on poor media or to germinate and grow on richer ones. Only one good symbiotic association was established. It was between Goodyera oblongifolia from British Columbia and Rs10, a rice pathogen from Malaysia.The results and their implications are briefly discussed.
Detection, spread, and aphid transmission of potato virus S
Authors: MacKinnon J. P.
Published: September 2008

Seventy-two potato tubers of 106 tested from plants exposed 1 year in a field were found infected with potato virus S (PVS) in different tests. Ninety-three percent of these were detected by tuber juice inoculation to Nicotiana debneyi Domin. and 90% by serology of 30-cm plants grown from an eye of such tubers. Sap inoculation to N. debneyi of the same young plants proved to be 96% efficient in detecting the virus, and serological tests at bloom stage were the most efficient of all the tests compared.Tests done on all tubers from 18 plants currently infected with PVS showed that 103 of 116 (89%) were infected, and virtually all eyes from 68 infected tubers produced infected plants.Three years of field trials at Fredericton on the spread of PVS showed that the virus moved into virus-free varieties independently of potato virus X (PVX). In 1970, leaf tests showed that virus-free Netted Gems became 12% infected with PVS; in 1971, spread into Green Mountain, Kennebec, and Sebago was 57, 19, and 9%, respectively; and in 1972, 14% spread occurred in Green Mountain and none in Kennebec or Sebago.Greenhouse experiments on transmission of PVS to potato by Myzus persicae (Sulz.) resulted in 3 of 87 (3.4%) plants becoming infected. Other tests with potato virus Y (PVY) to tobacco, Nicotiana tabacum L. var. Samsun, resulted in 83% transmission.
Peziza badia and Peziza badio-confusa
Authors: Elliott Mary E. , Kaufert Modra
Published: September 2008

Investigation of Peziza badia and P. badio-confusa based on herbarium specimens of North American material emphasized that these previously confused species can be distinguished by ascospore ornamentation and usually by fruiting habit, but not solely on ascospore length and width, which a statistical analysis indicated was unreliable for these species. Except at their northern limits, P. badia is an autumnal and P. badio-confusa a vernal species.
Etude histologique de la néoformation de méristèmes caulinaires et radiculaires à partir de segments d'entre-noeuds de Torenia fournieri cultivés in vitro
Authors: Chlyah H.
Published: September 2008

The histological study of the de novo formation of shoot and root meristems from inter-nodal segments of Torenia fournieri showed that buds are formed exclusively from epidermal cells and roots from endogenous perivascular tissue. It seems that there are no particular epidermal cells which are preferentially involved in the initiation of buds. This study showed the different and apparently specific potentialities of superficial and endogenous tissues.
The family Urticaceae in Canada
Authors: Bassett I. J. , Crompton C. W. , Woodland D. W.
Published: September 2008

Descriptions of major morphological features including those of the pollen, chromosome counts, and distribution data of the taxa of the family Urticaceae found in Canada are presented. There has been confusion in the species epithets applied to the genus Urtica. This study indicates that there are only three taxa in Canada: U. urens, 2n = 26; U. dioica ssp. dioica, 2n = 52; and U. dioica ssp. gracilis, 2n = 26 and 52. The tetraploid U. dioica ssp. gracilis ranges from the Rocky Mountains to the west coast while the diploid race occurs from the eastern side of the Rocky Mountains to the east coast. Artificial hybrids within the diploid race of Urtica dioica ssp. gracilis produced F1 plants with plenty of fertile seeds while a cross between a diploid and a tetraploid race of this taxon produced F1 plants with irregular chromosome pairing in the pollen mother cells and no seed set. The introduced U. dioica ssp. dioica ranges from Ontario to Newfoundland and the annual U. urens is widely scattered from the Yukon to Newfoundland. Laportea canadensis and Pilea pumila were found to have 26 somatic chromosomes; Boehmeria cylindrica, 28; and Parietaria pensylvanica, 16.
Properties of conjugation hormones (erogens) from the basidiomycete Tremella mesenteria
Authors: Reid Ian D.
Published: September 2008

Hormones produced by haploid cells of one mating type of T. mesenterica and inducing conjugation tubes in the other mating type have been studied in preparation for isolation and identification. The active material can be extracted from aqueous solution with n-butanol, but not with less polar solvents, and is adsorbed on cation and anion exchange resins, charcoal, and neutral polystyrene resin. The molecular weight is probably less than 1000. Three active components can be separated by silica gel column chromatography with a gradient of water in ethanol, or by paper chromatography. The conjugation hormones may be non-polar amino acids or small peptides.
The behavior of cytoplasmic membranes in Phaseolus vulgaris cotyledons during germination
Authors: Thompson J. E.
Published: September 2008

Information about the effects of germination on cytoplasmic membranes of cotyledons has been obtained by examining selected properties of smooth microsomes purified from cotyledon tissue at various stages of germination. The microsomal membranes contained rotenone-insensitive NADH – cytochrome c reductase (EC. 1.6.99.3) and NADPH – cytochrome c reductase (EC. 1.6.99.1). Measurements of these enzymes in smooth microsomal fractions isolated from various ages of cotyledon tissue revealed that their activities markedly decrease during the late stages of germination, coincident with onset of cotyledon senescence. This decrease is closely paralleled by a corresponding decline in total levels of the enzymes in the cotyledons during the same period, and has been interpreted as reflecting deterioration of cytoplasmic membrane structure and function concurrent with the progression of senescence. The membrane-bound cytochrome c reductase activity does not appear to be solubilized as a result of this deterioration. Furthermore, the protein:phospholipid ratios for the smooth microsomal preparations remain essentially unchanged during germination. This suggests that the macro-molecular complexes of membranes disaggregate more or less spontaneously during senescence and that in the process, the cytochrome c reductases are inactivated.
The Cirsium arizonicum complex of the southwestern United States
Authors: Moore R. J. , Frankton C.
Published: September 2008

The morphology, cytology, distribution, and phylogeny of eight species of the southwestern United States closely related to Cirsium arizonicum are considered. These species form a natural group distinguished from other North American species of Cirsium by a short stigma (1–3 mm) and long corolla lobes (10–20 mm) which are longer than the corolla throat. Three new species described are C. chellyense, C. chuskaense, and C. navajoense. Original chromosome counts are presented for C. nidulum, 2n = 34; C. rothrockii, 2n = 30; C. arizonicum, n = 15; C. chuskaense, 2n = 34; and C. arizonicum × nidulum, 2n = 32, 34.
Stellaria media embryogenesis: the development and ultrastructure of the suspensor
Authors: Newcomb William , Fowke L. C.
Published: September 2008

As early as the three-celled stage of embryogenesis, the basal cell of chickweed, Stellaria media, is larger than the other embryonic cells and contains large differentiating plastids, microbodies, and wall ingrowths of the transfer cell type at the micropylar end of the cell. Subsequent development produces a suspensor with unique plastids, microbodies, and extensive profiles of dilated endoplasmic reticulum not found in the embryo proper. The suspensor plastids, which appear to be different from any other plastids previously described on the ultra-structural level, are large and contain two types of tubules and electron-translucent inclusions. Plasmodesmata occur in the end walls but not in the side walls of the suspensor cells. It is suggested that the suspensor of chickweed is involved in important, possibly essential, translocation and metabolic activities during early embryogenesis.
Theoretical problems of interpreting floral organogenesis of Laportea canadensis
Authors: Macdonald Alastair D.
Published: September 2008

Conflicting interpretations exist regarding the nature of the urticaceous floral structures and the phylogenetic status of the Urticaceae. The differing interpretations have resulted from data being analyzed within the context of different conceptual frameworks. Therefore, the ontogeny of Laportea canadensis (L.) Wedd. is examined with a view to augmenting data of previous studies and toward determining where possible misinterpretations have occurred. Some of the assumptions implicit in the methodology of the various frameworks are examined to determine their meaningfulness. These assumptions, involving the notions of (1) a defined angiospermous floral archetype, (2) vascular conservatism, (3) mutually exclusive morphological categories, and (4) congenital fusion, are not considered useful, by this author, in comparative morphology. Guidelines are proposed that will facilitate the formulation of satisfactory assumptions, an appropriate methodology, and a meaningful conceptual framework that will form the basis of comparative morphology. The male and female flower of L. canadensis, as interpreted within the context of the proposed guidelines, may be thought to consist of an axis bearing lateral appendages. These consist of the four or five perianth members, the gynoecial wall, and the two integuments. The nucellus is the transformed apex in the female. The integuments are not formed in the same manner as the other appendages. The gynoecium is not, by definition, carpellate since it does not bear the ovule. The stamens form in the axil of the perianth members and may be considered more stem-like than leaf-like. The phylogenetic status of this species remains problematical.
Taxonomy of Lupinus aridus (Papilionaceae: Genisteae)
Authors: Cox Billy J.
Published: September 2008

A taxonomic revision of Lupinus aridus Dougl. ex Lindl. is presented. Two new subspecies, ashlandensis and loloensis, are described, and a change in taxonomic status of L. lenorensis is made. The treatment includes synonymies, typifications, descriptions, lists of exsiccatae, photographs of typical herbarium specimens, illustrations of typical flower, leaf, and stem parts, phylogenetic discussions, keys, and distribution maps.
Environmental factors affecting germination of Cronartium comandrae aeciospores
Authors: Powell J. M.
Published: September 2008

Cronartium comandrae Pk. aeciospores germinated over the temperature range 1 to 30 °C, but germination outside the range 5 to 22 °C was poor. Optimum for germination was about 15 °C, although initial germination was better at 20 °C. Some aeciospores germinated after 1 h of incubation and most within 4 to 5 h. The rate of germ tube elongation was reduced after 8 h, and generally had ceased after 24 h. Each spore produced an average of two germ tubes, but only one developed. Appressoria usually formed only at 15 and 20 °C. Free water was apparently necessary for germination. Hydration of spores initially improved germination but extended periods of hydration decreased it. Viable spores swelled more than non-viable spores. Aeciospores germinated well in the dark and in light but not in direct sunlight. Fresh aeciospores germinated on media with a pH range of 4.5 to 8.0, but did best between pH 6.0 and 6.5. Germination results are compared with those reported for other Cronartium rusts.
Oxygen uptake by motile and germinating zoospores of Pythium aphanidermatum
Authors: Chang-Ho Yung
Published: September 2008

Oxygen uptake by Pythium aphanidermatum zoospores during motility, encystment, and germination was measured. Addition of glucose or fructose had no appreciable effect on motile zoospore respiration. The effects of various substrates on the respiratory rate of germinating cysts were as follows: glucose, glucose-6-phosphate, xylose, acetate, citrate, glutamate, and 6-phosphogluconate did not increase the respiratory rate; whereas fructose, fructose-6-phosphate, iructose-l,6-diphosphate, sucrose, alphaketoglutarate, pyruvate, and dilute pea root exudate all significantly increased cyst respiration.
A red snow in Ontario caused by the dinoflagellate, Gymnodinium pascheri
Authors: Gerrath J. F. , Nicholls K. H.
Published: September 2008

The first record of an algal red snow from Ontario is reported. The organism causing the red snow is identified as the dinoflagellate Gymnodinium pascheri (Suchlandt) Schiller; this is the first record of this plant in North America.
Recherches sur les Alaria (Phaeophyceae) de l'est canadien. I. Nombres chromosomiques et identité des Alaria de l'estuaire du St-Laurent
Authors: Feller-Demalsy M.-J. , Demalsy P.
Published: September 2008

Chromosome counts in gametophytes and sporophylls of Alaria collected in the St. Lawrence Estuary show that all the specimens of this genus in eastern Canada may not belong to the single species A. esculenta Greville. Indeed, the haploid chromosome number (n) found in these algae is equal to half of the number attributed in the literature to Alaria esculenta from the British coasts. Three hypotheses for the interpretation of these observations are considered. The solution of the problem of the identity of Alaria can only be hoped for from their global, morphological, and biosystematic study.
Nicotinamide adenine dinucleotide metabolism in plants. II. Responses of nicotinamide nucleotides to chemical regulators in bean leaves
Authors: Chen S. C. , Godavari H. R. , Waygood E. R.
Published: September 2008

Incorporation of nicotinic acid-7-14C into nicotinamide adenine dinucleotide by the trifoliate leaves of the bean plant (Phaseolus vulgaris L. var. Brittle Wax) was studied for varying time periods from 5 min to 48 h. Nine radioactive compounds were isolated and identified as all the possible intermediates of NAD metabolism operating in a cyclic pattern. All the intermediates were labelled rapidly and N-methyl nicotinic acid (trigonelline) was detected within 5 min. About 80% of the nicotinic acid fed was accumulated in trigonelline. Senescence induced by floating detached leaves on water enhanced incorporation of the label into nucleotides, NAD > NADP. Treatment with growth regulators altered the NAD/NADP ratios. Benzimidazole and kinetin enhanced NADP synthesis while benzyladenine and ethionine reduced NADP synthesis. The regulator-mediated NADP synthesis is enhanced by light and appears to be inversely related to the synthesis of trigonelline.
Some aspects of the nitrogen metabolism of Nodularia spumigena (Cyanophyceae)
Authors: Camm E. L. , Stein J. R.
Published: September 2008

Nitrate-reducing ability, NO2−-reducing ability, and glutamic acid dehydrogenase levels were measured in two clones of Nodularia spumigena Mertens. Measurements with whole cells of both clones show that NO3− reduction is stimulated by NO3−, and that NO2− reduction is probably stimulated by NO2−. The NO3−-reducing system is stimulated by light and inhibited by NH4+. These controls and possible control over NH4+ incorporation into amino acids are compared to systems operative in other organisms.Differences in growth and physiology of the clones in growth rate on N-free medium, growth inhibition by urea, and NO2− accumulation in the medium are discussed.
Dark CO2 fixation by cell-free preparations of the wood of Robinia pseudoacacia
Authors: Höll Wolfgang
Published: September 2008

In the presence of phosphoenolpyruvate, cell-free preparations from distinct annual ring tissues of the trunk and the root of Robinia pseudoacacia L. incorporate 14CO2 into organic compounds. The CO2 fixation process exhibits a pH optimum at 7.8 and is activated by Mg2+. Aspartic acid contained 97% of the radioactivity incorporated. Oligosaccharides, malic acid, fumaric acid, glutamic acid, and three substances not identified with certainty show minor labeling. The activities of malate dehydrogenase (EC. 1.1.1.37), aspartate aminotransferase (EC. 2.6.1.1), and "malic enzyme" (EC. 1.1.1.40), involved in the further metabolism of the primary CO2 fixation product oxaloacetate, were detected spectrophotometrically in preparations from different annual rings of the trunk. Compared with the outer zones, the innermost part of the sapwood shows only little activity of these enzymes. The capacity to transfer CO2 into organic compounds decreases in the radial direction of both trunk and root wood. Heartwood preparations exhibit no CO2 fixation. In comparison to the trunk, the wood of the root shows only little dark CO2 fixation. The possible physiological role of this nonautotrophic CO2 binding in the wood of Robinia is discussed.
Control of morphogenesis in the ethylene-requiring tomato mutant, diageotropica
Authors: Zobel R. W.
Published: September 2008

Diageotropica (dgt) is a single gene mutant of tomato which requires extremely low concentrations of ethylene for normal growth and development. The morphology of the mutant is charactertized by diageotropic growth of both shoots and roots, thin stems without large secondary xylem vessels but with abnormally thick phloem fibers, dark green hyponastic leaf segments, primary and adventitious roots without lateral branching, and an open hypocotyl hook. Studies with the mutant indicate that plant morphology may be at least partly controlled developmentally by an endogenous ethylene–auxin feedback mechanism. The mutant's requirement for ethylene concentrations in the range of 0.005 μl/liter or less implies that higher concentrations may be supraoptimal in studies dealing with ethylene effects on plant growth and development in tomato. Results of grafting and excised root culture experiments combined with results of ethylene treatments indicate that a polarly transported substance, which controls lateral root initiation but not adventitious root initiation, is produced in the shoot in response to ethylene and transported to the roots. The dgt mutant should prove useful in investigations of ethylene and auxin control of morphogenesis.
Variability in peroxidase isozymes in wheat and related species
Authors: Kobrehel Karoly , Gautier Marie-Françoise
Published: September 2008

Polyacrylamide-slab gel electrophoresis showed that the nature of peroxidases in wheat is a genetic character; different genomes control the synthesis of specific peroxidases. The growing conditions have no influence on isozyme patterns. Within a single species the electrophoretic patterns of peroxidases may differ from one variety to another. Thus, two classes of Triticum aestivum can be distinguished. With Triticum durum the dissimilarity of enzymograms is particularly important.
Inhibition of sugarcane rooting by Ceratocystis paradoxa
Authors: Byther Ralph S. , Moore Paul H.
Published: September 2008

Sugarcane rooting was inhibited by Ceratocystis paradoxa on both pathogen-invaded setts and disease-free setts suspended above cultures of the fungus. Root inhibition was not correlated with differences in clonal susceptibility. Volatiles from cultures of the pathogen caused root inhibition and a concomitant rise in host-tissue production of ethylene. Apparently the host tissue is stimulated to produce ethylene both directly by tissue invasion and indirectly by fungal volatiles. The ethylene produced is then in part responsible for the observed root inhibition.
The cultivation of rust fungi upon artificial media
Authors: Wolf Frederick T.
Published: September 2008

While the rust fungi have long been regarded as obligate parasites, within recent years nine species belonging to four different genera have been grown in pure culture in the laboratory. Gymnosporangium juniperi-virginianae and Uromyces caladii have been isolated from tissue cultures of their infected hosts. A culture of Puccinia malvacearum originated from a teliospore, promycelium, or basidiospore. Puccinia graminis tritici, P. graminis avenae, P. recondita trilici, P. helianthi, Melampsora lini, and Uromyces dianthi have been isolated from germinating uredospores. Melampsora lini has also been isolated through treatment of infected host tissues with hydrolytic enzymes. Some of the cytological, physiological, and biochemical findings resulting from studies of these pure cultures are discussed.
Radioisotopic analyses of acid polysaccharide metabolism in Pilayella littoralis
Authors: Leppard Gary G.
Published: September 2008

Pilayella littoralis has a cytomembrane system which discretely connects carbohydrate-synthesizing organelles to polysaccharide-synthesizing organelles. The vegetative cell can rapidly synthesize large quantities of 14C-labeled acid polysaccharides from Na214CO3 added to its culture medium. Radioautographs prepared so as to retain insoluble acid polysaccharides, but not their precursors, show label in the Golgi region and those cytoplasmic regions containing motile TBO particles. Light pulse – dark chase experiments indicate both a prolonged synthesis of polymers during chases and a transfer of polymers from the cytoplasm to the cell wall. Radioisotope extract analysis shows a prolonged synthesis of acid polysaccharides during dark chases, with most of the label found in the alginic acid fraction and some unknown polymers of the alpha-cellulose fraction. The findings are discussed in terms of known phaeophycean metabolism and Pilayella ultrastructure.
Confusion in the names of three Draba species of the arctic: D. adamsii, D. oblongata, and D. corymbosa
Authors: Mulligan Gerald A.
Published: September 2008

The correct nomenclature and differences between Draba adamsii Ledebour (n = 16), D. oblongata R.Br. ex DC. (n = 32), and D. corymbosa R.Br. ex DC. (n = 72) are given. Plants previously referred to as D. oblongata, D. micropetala, and D. leptopetala should be named D. adamsii Ledebour. The earliest legitimate name for another taxon is D. oblongata R.Br. ex DC. not D. groenlandica E. Ekman. The third taxon should be referred to as D. corymbosa R.Br. ex DC. rather than D. bellii Holm or D. macrocarpa Adams.
Studies on the behavior and survival of Phytophthora cactorum in soil
Authors: Sneh B. , McIntosh D. L.
Published: September 2008

Sporangia and oospores of P. cactorum persisted for appreciable periods in soil at temperatures and soil water contents likely to prevail during a growing season.Mycelium lysed more rapidly as soil water content and temperature increased. Hyphae were not viable after 3 days incubation in wet soil at 29 °C but survived for at least 45 days at 4 °C.At soil water contents higher than 3.0 bars suction and at soil temperatures above 10 °C sporangia appeared on mycelium buried in soil. When soil moisture was reduced to 3.0 bars suction and temperature to 10 °C, oogonia were formed.Longevity of sporangia was reduced by increasing soil water content above 0.3 bars suction. Glucose added to soil induced germination of sporangia and germ tube elongation, while asparagine inhibited germination.Sporangia and oospores but not mycelium survived freezing temperatures in moist soil. Sporangia could not be recovered from soil which had been allowed to dry. Some oospores germinated after drying.
New species of Hypocopra (Xylariaceae)
Authors: Krug J. C. , Cain R. F.
Published: September 2008

Hypocopra (Fr.) Kickx is used for those representatives of the Xylariaceae typically possessing sessile, clypeoid, or reduced stromata; asci with a complex apical apparatus staining blue or brick-red in Melzer's reagent; either unicellular dark-walled ascospores or bicellular ascospores with one large dark-walled cell and a very small hyaline cell; and a single germ slit of variable length in the ascospores of the different species. A synoptic key to all currently recognized species is provided. One new combination, H. hypocoproides (Sordaria hypocoproides Speg.), is described and illustrated along with fourteen new species: H. annulata, found on deer and moose dung from Sweden and U.S.A.; H. anomala and H. keniensis, both on burro and cow dung from Kenya and Mexico; H. bicolor and H. cataphracta, both on horse dung from U.S.A.; H. dolichopoda, on horse, cow, deer, and rabbit dung from Canada and U.S.A.; H. elachyglossina, on horse, cow, and goat dung from Bulgaria, Canada, Spain, Sweden, and Yugoslavia; H. festucacea, on red-deer, moose, and wapiti dung from Canada and Switzerland; H. pachyalax, on horse, donkey, and rabbit dung from Canada, Spain, and U.S.A.; H. phorcodes, on burro and cow dung from Mexico; H. planispora, on hare and rabbit dung from Canada, Scotland, and Sweden; H. plinthina, on horse and cow dung from Canada and U.S.A.; H. punicea, on cow dung from Kenya, Mexico, and the Virgin Islands; and H. stephanophora, on horse dung from England and U.S.A.
Phosphorylation and respiration of dwarf and normal pea mitochondria and respiration of internodal sections
Authors: Israelstam G. F. , Fukumoto K.
Published: September 2008

A comparative examination of the rates of respiration of dwarf and normal internodal segments was undertaken. The results indicated that on a fresh weight basis respiration was faster in the normal variety than in the dwarf.A comparison of the mitochondrial respiration, using succinate and reduced nicotinamide adenine dinucleotide (NADH) as substrates, showed that mitochondria from the normal variety had significantly higher phosphate to oxygen (P:O) and respiratory control (RC) ratios than mitochondria from the dwarf. It was suggested that the stature of the dwarf variety was a result of a lower energy status and that mitochondria from the dwarf plant may be partially uncoupled.
Formation and propagation of cell division-centers in the epidermal layer of internodal segments of Torenia fournieri grown in vitro. Simultaneous surface observations of all the epidermal cells
Authors: Chlyah Hassane
Published: September 2008

A cytological study of bud neoformation was done using a technique of direct observation of whole epidermal strips excised and stained at different stages of development from one side of an internodal segment of Torenia fournieri grown in vitro. It was shown that cell divisions start at random points over the epidermis and spread out progressively and apparently by contagion, forming cell division-centers. These centers are each formed of a central, highly divided cell surrounded by several less divided cells. The number of divisions per original cell decreases with the distance from the highly divided central cell.The probable origin of bud meristems was shown to be either one part of an original cell, one cell, several parts of adjacent cells, or several entire adjacent cells.A competition phenomenon was shown to exist between cell division-centers; few centers form meristematic primordia and only a few of these last form buds (about 20). Thus, on an epidermal strip 10 × 2.5 mm containing about 5000–6000 cells, fewer than 100 cells are implicated in the formation of buds observed morphologically.
Scanning ultrastructural ontogeny of paragymnohymenial apothecia in the operculate discomycete Peziza quelepidotia
Authors: O'Donnell K. L. , Hooper G. R.
Published: September 2008

Morphogenesis of apothecia in Peziza quelepidotia Korf and O'Donnell, a homothallic operculate discomycete (Pezizales, Pezizaceae), was investigated with the scanning electron microscope from ontogeny of the ascogonial coils through spore discharge. Since the incipient paraphyses are never completely closed by the overarching ectal excipular margin, hymenial development is classified as paragymnohymenial. At the late mesohymenial phase, operculate asci protrude as much as 25–35% of their length above the level of the paraphyses. Patches of hyphoid processes in the hymenium may function to preserve the hymenial compactness in the late-mesohymenial to telohymenial ascocarps. The microanatomy of the excipula, as revealed by median longitudinally sectioned ascocarps, is characteristic for the genus. In addition, an abberant, bicupulate ascocarp is figured.
Generic limits in the Pyroloideae (Ericaceae)
Authors: Haber Erich , Cruise James E.
Published: September 2008

A reevaluation of the generic limits within the Pyroloideae is presented, taking into consideration the more recent evidence of chromosome number within the group. Chromosome number is correlated with more obvious morphological features, many of which have been the prime basis for the delimitation of generic boundaries in earlier treatments. Brief consideration is given also to the implications of data obtained from a thin-layer chromatographic analysis of the subfamily.Three generic segregates from within the original broad concept of the genus Pyrola are recognized. The diploid chromosome numbers which have been reported for Orthilia secunda (L.) House (2n = 38) and Moneses uniflora (L.) Gray and Chimaphila spp. (2n = 26) in conjunction with discrete differences in inflorescence types and floral modifications among these taxa serve as useful characteristics on which to base their recognition as genera distinct from Pyrola s.str. (2n = 46).
Female gametophyte and embryo development in western hemlock (Tsuga heterophylla)
Authors: Stanlake Elizabeth A. , Owens John N.
Published: September 2008

A morphological study of the female gametophyte and embryo development was made for western hemlock (Tsuga heterophylla (Raf.) Sarg.) growing in the Victoria, B.C., area. Western hemlock follows a pattern of development similar to other members of the Pinaceae. A comparison was also made between development in western hemlock and other gymnosperm families. Meiosis of the megaspore mother cell in western hemlock begins in early February and is completed at the end of the first week in March. This is 3 weeks before pollination. Fertilization occurs 6 weeks after pollination, in the middle of May. Embryo development takes place throughout June and July and the embryo is mature by the middle of August. Seed fall occurs throughout September, 5 months after pollination.
Cauline rosettes — an asexual means of reproduction and dispersal occurring after seed formation in Barbarea vulgaris (yellow rocket)
Authors: MacDonald Marilyn A. , Cavers Paul B.
Published: September 2008

A previously unreported method of asexual reproduction has been found in Barbarea vulgaris. It involves the formation of a rosette of leaves (similar to those of the basal rosette) on the inflorescence after seed formation. If the stalk is bent to the ground, adventitious roots from the cauline rosette can become established. Eventually, if it survives overwinter, this new plant may bolt and flower.
Comparison of soluble proteins of Ascocalyx abietis and Gremmeniella abietina by serology and electrophoresis
Authors: Dorworth C. E.
Published: September 2008

Soluble proteins of Gremmeniella abietina were compared with those of Ascocalyx abietis by immunodiffusion against rabbit antisera and by acrylamide gel electrophoresis. Three of the homologous reactions of G. abietina and the antisera were confluent with the heterologous precipitation lines of A. abietis against the same antisera. Acrylamide gel patterns of the separated proteins of two genera differed by at least one band.
The major organic components and caloric contents of high arctic bryophytes
Authors: Pakarinen Pekka , Vitt Dale H.
Published: September 2008

Thirty-five bryophyte species representing the major habitats of a high arctic tundra lowland (Devon Island, Canada, 75° N) have been analyzed for contents of nitrogen, carbon, ash, and ether- and alcohol-soluble fractions. Mean contents (%) for the green portion of these species are total nitrogen, 1.00 (1.08 ash-free); total carbon, 45.9 (48.7 ash-free); ether-soluble fraction, 2.8 (3.0 ash-free); alcohol-soluble fraction, 11.8 (12.5 ash-free); and ash, 5.7. In the hydric species group, the total nitrogen content and the alcohol-soluble fraction are significantly greater than in mesic or xeric groups. When the green and brown segments are compared, the nitrogen content and the alcohol-soluble fraction are greater in the green portion, while the ash content is higher in the brown portion. The ash-free caloric values of hydric species range from 4.57 to 4.97 kcal/g, while the mesic and xeric species have a range from 4.50 to 4.69 kcal/g. The relations between habitats and between the green and brown portions are discussed in relation to general metabolic activity and productivity.
Studies on lichen-dominated systems. VII. Interaction of the general lichen–heath with edaphic factors
Authors: Larson Douglas W. , Kershaw Kenneth A.
Published: September 2008

The patterns of variation in vegetation and the more apparent environmental parameters within and between the ridges of a recently formed Hudson Bay coastal raised-beach system 1.5 km wide are presented and analyzed using principle-component analysis and correlation coefficients. Previous research in the area did not detect such patterns within the general lichen–heath.There is a marked developmental sequence from the coast inland, involving increases in the soil moisture content and the peat-layer thickness, but variations independent of any age sequence occur on an intraridge basis. Relationships are drawn between these variations and the biomass or cover of nine important species.
Some properties and thrip transmission of tomato spotted wilt virus in Canada
Authors: Paliwal Y. C.
Published: September 2008

A virus isolated from white clover (Trifolium repens L.), dahlia, and tomato from Ontario, dahlia from Manitoba, and tomato and dahlia from British Columbia was identified as tomato spotted wilt virus (TSWV). Seven isolates of the virus examined had similar host reactions; four of them, investigated in detail, were similar in their localization in tomato leaf cells and physical properties also. The virus particles, 78–97 nm in diameter, were abundant in tomato leaf mesophyll cells and occurred in clusters or arrays surrounded by a membrane.The virus was purified by a method modified from a previously reported one and a specific antiserum was prepared. TSWV appears to be weakly immunogenic, as a high titer antiserum could not be obtained.At least three species of thrips, i.e. Thrips tabaci Lind., Frankliniella fusca Hinds, and F. occidentalis Perg., known as vectors of TSWV elsewhere, occur in Canada. F. fusca, which occurs in eastern Canada, efficiently transmitted all isolates of the virus. T. tabaci, a vector in several countries and widespread in Canada, failed to transmit the virus.