bluuebunny/crossref_metadata_2025 huggingface dataset:
CONTRIBUTION TO THE EMBRYOLOGY OF HOPPEA DICHOTOMA WILLD. (GENTIANACEAE)
Authors: Arekal Govindappa D.
Published: August 2008

The mode of embryo sac development in Hoppea dichotoma Willd. conforms to the Polygonum type. No integumentary tapetum is organized around the female gametophyte. The organization of the endosperm follows the nuclear type. Simultaneous cell wall formation occurs throughout the endosperm when the embryo is at the 4- to 6-celled stage. The development of the embryo is assigned to the second period, V megarchetype and group 11 in series C′ in the system of embryogenic classification of Souèges. The endosperm and embryo of Gentianaceae are compared with those of Menyanthaceae.
EFFECT OF RUST-INHIBITING COMPOUNDS ON THE METABOLISM OF WHEAT LEAVES
Authors: Samborski D. J. , Rohringer R. , Person Clayton
Published: August 2008

Healthy leaves of Little Club wheat (Triticum compactum Host.) and leaves infected by leaf rust (Puccinia recondita Rob. ex. Desm. race 5) were detached and floated for 3 days on solutions containing 10 p.p.m. canavanine, 0.1% azathymine, 0.125% dulcitol, and 0.1% methionine. Leaf samples were fed with uniformly labelled glucose for 24 hours, fractionated, and the C14-content of each fraction was determined. Compared with controls, canavanine slightly reduced the amount of C14in amino acids, nucleic acids, and proteins while 6-azathymine markedly reduced the amount of C14in nucleic acids and proteins. Treatment with dulcitol resulted in a lower recovery of C14from all fractions other than sugars while methionine had little effect on the distribution of C14from glucose. Quantitative analyses showed a marked increase in amino acids after canavanine, 6-azathymine, and methionine treatments and a reduced level of nucleic acids after treatment with canavanine and azathymine.Canavanine had no effect on the incorporation of arginine and glutamic acid into leaf proteins while 6-azathymine inhibited the incorporation of adenine into nucleic acids. It was not possible to relate the changes that occurred following these treatments to the in vivo metabolism of the rust fungus.
THE ASSOCIATION BETWEEN AGE OF INFLORESCENCE AND NECTAR PRODUCTION IN THE LOW-BUSH BLUEBERRY VACCINIUM ANGUSTIFOLIUM
Authors: Wood G. W.
Published: August 2008

Nectar samples were harvested daily from exposed and caged portions of the low-bush blueberry, Vaccinium angustifolium (varieties laevifolium House and nigrum (Wood) Dole). Pollination activity on the exposed bloom had no significant effect on mean nectar volume and concentration but caused a slight reduction in the mean weight of nectar sugar. Nectar volume and weight of nectar sugar increased directly with the age of inflorescence in all clones.
TYPIFICATION OF THE LINNAEAN SPECIES OF CARAGANA
Authors: Moore Raymond J.
Published: August 2008

Four species of Caragana were described by Linnaeus under the genus Robinia. The following specimens in the Linnaean Herbarium of the Linnaean Society of London are selected as lectotypes of these species: C. arborescens Lam., spec. 913.5; C. frutex (L.) Koch, spec. 913.6; C. pygmaea (L.) DC., spec. 913.8. The type of the genus Caragana is spec. 913.5. The location of the type of C. spinosa (L.) DC. is unknown.
GROWTH OF CERATOCYSTIS ULMI (BUISMAN) C. MOREAU IN LIQUID CULTURE MEDIA
Authors: Gagnon Camilien
Published: August 2008

Ceratocystis ulmi (Buism.) C. Moreau was grown in liquid media with four different nitrogen compounds, eight sugars, and four concentrations of glucose. The fungus was grown at room temperature in the dark as still cultures, and in daylight as still and as shake cultures. The pH of the culture filtrates appeared to be dependent on the sugar used as the main source of carbon. The dry weight of the fungus fluctuated regularly with age. This is shown to be independent of the factors investigated and has been attributed to autolysis of the fungus. Implications of the findings are discussed.
CARPOPHORES OF PHLEBOPUS SULPHUREUS IN CULTURE
Authors: Pantidou Maria E.
Published: August 2008

Phlebopus sulphureus (Fr.) Sing., possibly a mycorhizal fungus, produced mature carpophores in culture. This is the first report of a species of Boletaceae fruiting in culture. The developmental stages of the fruit bodies are described.
A FUSARIUM CANKER DISEASE OF POPULUS DELTOIDES MARSH.
Authors: Boyer M. G.
Published: August 2008

Two morphologically distinct types of Fusarium solani sensu S. & H. induce a characteristic canker disease on P. deltoides on low-lying sites in Quebec. Studies on the morphology and pathogenicity of the causal organism are presented.
MARINE NANNOPLANKTON FROM A BRITISH COLUMBIA FJORD
Authors: Scagel Robert F. , Stein Janet R.
Published: August 2008

The qualitative aspects of the nannoplankton in Indian Arm, British Columbia, have been heretofore unknown, although the relative quantitative significance of this difficult group of unicellular organisms is apparent from recent primary production studies using the carbon-14 method. This qualitative study of samples collected in the spring of 1960 in Indian Arm has added a number of new records of distribution for the area (Chromulina sp., Ochromonas ?vallesiaca Chodat, Chrysochromulina sp., Thallasomonas exurgens Butcher); and has led to the discovery of several new species and genera (Chrysamoeba nana sp. nov., Microsportella gen. nov. fiordensis sp. nov., Xanthomonas gen. nov. thalassoides sp. nov., Pseudomicrosportella gen. nov. ornata sp. nov., and Anisomonas astigmatica sp. nov.). The study is being continued to determine qualitatively the seasonal and three-dimensional distribution of these and other nannoplankton in the fjord in relation to the physical–chemical aspects of the environment.
NEW SPECIES OF THE GENUS CERATOCYSTIS
Authors: Wright Elaine F. , Cain Roy F.
Published: August 2008

A study of the species of Ceratocystis found in Ontario on decaying slash has been made and most of the species grown in pure culture. The characteristics of the genus and the separation of species are discussed. Four species found on wood of coniferous trees are described as new. Illustrations are included for all of these. Ceratocystis brunneocrinita Wright and Cain is described from several collections of Abies balsamea. The perithecia have brown ostiolar hyphae and the ascospores appear rectangular. Ceratocystis europhioides Wright and Cain, on Pinus and Picea, has ascospores similar to but larger than the nonostiolate Europhium trinacriforme Parker. Ceratocystis falcata Wright and Cain, on Pinus, resembles Ceratocystis minuta (Siem.) Hunt but is distinguished by the longer, septate ascospores. Ceratocystis sagmatospora Wright and Cain, on Pinus and Picea, has saddle-shaped ascospores with elaborate gelatinous sheaths.
THE LIGHT COMPENSATION POINTS OF SOME HERBACEOUS PLANTS INSIDE AND OUTSIDE DECIDUOUS WOODS IN GERMANY
Authors: Lieth H. , Ashton D. H.
Published: August 2008

The light compensation points and respiration rates of cut leaves of Ranunculus ficaria, Anemone nemorosa, and Allium ursinum were determined at 18–19 °C at intervals throughout the growing season of 1959 from plants grown inside and outside the forest. The light compensation points of leaves from inside and outside the forest decreased progressively during the growing season from March to June, but showed two sharp increases following severe frosts in the mid-season. The compensation points of plants in the forest were consistently lower than those in the open, and showed a smaller increase due to frost damage. The drift in light compensation points could in most cases be correlated with a decrease in the dark-period respiration rate. However, the marked exceptions which occurred after the frosts were presumably due to a decrease in the efficiency of photosynthesis.The light compensation points of Allium were consistently lower than those of Anemone, which were in turn frequently lower than those of Ranunculus. Field observations suggested that Allium was the most tolerant of shade conditions and persisted above ground for the longest period under the forest canopy. When the light compensation points of these species were compared on the basis of equal respiration rates, Allium was lowest and presumably had the most efficient photosynthetic apparatus and Anemone was highest and presumably had the least efficient.
TRIGLOCHIN GASPENSE, A NEW SPECIES OF ARROW GRASS
Authors: Löve D. , Lieth H.
Published: August 2008

A new species, Triglochin gaspense Lieth & D. Löve, is described from a salt marsh between Barachois-Ouest and Coin-du-Banc, Gaspé Peninsula, Quebec, Canada. It is distributed in Quebec, the Canadian Maritime Provinces, and Newfoundland, as well as in at least the northern part of the state of Maine, U.S.A. It is well differentiated from the other American species of the Triglochin maritimum complex, to which it belongs, morphologically (5–20 cm tall, leaves overtopping the short, few-flowered spike), cytologically (2n = 96 chromosomes), and ecologically (confined to the tidal zone of the Atlantic coast below the high-water mark). The type specimen of the new species is preserved in the Marie-Victorin Herbarium, Université de Montréal.
FIELD GRAFTING WITH HEALTHY AND NEEDLE-BLIGHTED EASTERN WHITE PINE TREES AND THE EXPRESSION OF DISEASE SYMPTOMS
Authors: Linzon S. N.
Published: August 2008

Healthy and needle-blighted eastern white pine trees (Pinus strobus L.) were intergrafted in the forest using bottle and cleft crown graft techniques. The grafts were made in four combinations of diseased and healthy scions and stock branches and at three different stages of development of the graft components. High percentages of successful grafts were obtained when the partner combinations included healthy scions and when the grafting was done in early May with active top growth just beginning in both scions and stock. Fewer grafts survived when diseased scions were employed and when the field grafting was carried out with dormant-collected scions or with scions and stock both possessing advanced new growth.Each grafted partner retained its original identity. Needle-blight symptoms appeared simultaneously on diseased scions and their mother trees, while the healthy stock trees remained unaffected. Conversely, healthy scions and their mother trees were unaffected while the diseased stock trees displayed the needle-blight symptoms on their foliage. No disease symptoms were transmitted by stem grafting. A search revealed that perennially needle-blighted trees were joined to neighboring healthy trees by natural root grafts, and that there was no visible communication of the disease symptoms. Additional evidence has been presented to show that needle blight is nonparasitic in etiology and that susceptibility to needle breakdown is inherent in the individual.
BOTANICAL STUDIES ON MONT ST. HILAIRE, ROUVILLECOUNTY, QUEBEC: GENERAL DESCRIPTION OF THE AREA AND A FLORISTIC SURVEY
Authors: Maycock P. F.
Published: August 2008

The Monteregian Hills are a series of eight mountains, intrusive in nature, which form a distinct petrographical province in the St. Lawrence Lowlands of Southern Quebec. Mont St. Hilaire, one of the larger members of the group, was bequeathed to McGill University as a natural area for scientific research in 1959 by the late Brigadier A. Hamilton Gault. During a survey of the natural resources of the mountain throughout the summer of 1959, botanical investigations of the flora and vegetation were conducted. The present report is the first in a series that will present the results of these studies. It is concerned with the general characteristics of the mountain and the known existing flora.
PHYSIOLOGICAL STUDIES ON A NECROTIC MUTANT OF CORN
Authors: McCalla D. R.
Published: August 2008

The leaves of homozygous nec. 1 plants (a single-gene, necrotic maize mutant) develop visible necrotic symptoms when they are exposed to light for several days. Extensive analysis has failed to reveal any difference in chemical composition between leaves of normal plants and of homozygous nec. 1 plants before the necrotic symptoms are visible (prenecrotic leaves). Treatment of nec. 1 seedlings with various metabolites (B vitamins, purines, pyrimidines, amino acids, etc.) did not prevent the appearance of necrosis. The rate of photosynthesis of prenecrotic leaves is normal at low light intensities but only 20 to50% of normal at saturating light intensity. C14O2feeding experiments indicate that the photosynthetic carbon-fixing reactions function normally in the mutant. Hill reaction rates are also similar in mutant and normal plants, as is the metabolism of labelled inorganic phosphate. 3-(p-Chlorophenyl)-1,1-dimethylurea, which specifically inhibits photosynthesis to the extent of about 90%, delays the onset of visible necrotic damage and reduces the severity of subsequent necrotic symptoms. It is suggested that the basic lesion in nec. 1 plants lies in a reaction associated with photosynthesis and that it causes the accumulation of one or more toxic substances. These materials lower the rate of photosynthesis and damage cell membranes. The necrotic phenotype would appear to be the result of the breakdown of cell compartmentalization.
SPORE DISPERSAL IN POLLACCIA RADIOSA (LIB.) BALD. AND CIF.
Authors: Dance B. W.
Published: August 2008

The effects of environmental and silvicultural factors on the dissemination and concentration of spores of Pollaccia radiosa (Lib.) Bald, and Cif. in the air were studied at Chalk River, Ontario. Relationships were found to exist between the concentration of spores in the air, rain showers, the time of year, and the susceptibility of the host(s); a knowledge of these may be valuable in controllingthe pathogen.
SOMATIC MITOSIS IN A BASIDIOMYCETE
Authors: Ward E. W. B. , Ciurysek Kathleen W.
Published: August 2008

The nuclei in stained preparations of the mycelium of an unidentified basidiomycete were shown to divide by mitosis. Typical stages of division with the exception of early prophase were clearly distinguished and the haploid chromosome number was shown to be 4. The view that the fungus is a basidiomycete was confirmed by the demonstration of conjugate nuclei and clamp connections.
STUDIES OF THE CULTURE OF ATROPELLIS PINIPHILA
Authors: Hopkins J. C.
Published: August 2008

Isolates of Atropellis piniphila were grown from single ascospores, and from cankers on lodgepole pine. A variety of media were tested for their capacity to support growth of the isolates. Descriptions of cultural and microscopical characters were prepared. Endoconidia were produced abundantly by most of the isolates after growth at 50%, or higher, relative humidity, but they were absent from most of the cultures which had been grown at 10% relative humidity. Attempts to grow apothecia in culture were unsuccessful. The cardinal temperatures for growth occurred at 4°, 18°, and at 24 °C. The optimum pH for growth in buffered media occurred at between 3.0 and 4.0. In media containing varying concentrations of carbon and nitrogen, growth was maximal on those containing 4% dextrose and 0.4% ammonium succinate. Of seven vitamins tested, a deficiency for thiamine alone was demonstrated.
STUDIES ON SLIME ACCUMULATIONS IN PULP AND PAPER MILLS: V. PRELIMINARY OBSERVATIONS ON THE EFFECT OF EXTRACTS OF SPRUCE AND FIR ON THE GROWTH OF PHIALOPHORA FASTIGIATA
Authors: Brewer D.
Published: August 2008

Water and acetone extracts of balsam fir, black spruce, white spruce, and red spruce have been shown to be stimulatory to the growth of an isolate of Phialophora fastigiata when added to a complete basal medium. Fractionation of the extracts has shown that the woods differ in the nature of their stimulatory substance or substances. Biotin was indicated as the active compound in some of the fractions. The number and nature of the other substances are as yet unknown.
STUDIES ON ASCOCHYTA IMPERFECTA PECK. DIFFERENTIAL UTILIZATION OF NUTRIENTS BY ISOLATES FROM CANADIAN ALFALFA SEED
Authors: Mead H. W.
Published: August 2008

Isolates of Ascochyta imperfecta which had reacted differentially to 10 leguminous hosts were grown on a basic medium amended with various sugars, amino acids, and nitrogen sources. Significant differences in the yield of mycelium on the various media showed that these isolates responded specifically to different sugars and amino acids. Among the latter, cystine at 0.025% was inhibitory to all isolates. The significance of changes in the host on development of the fungus is discussed.
INTERSPECIFIC HYBRIDIZATION IN LOBELIA L. SECTION LOBELIA
Authors: Bowden Wray M.
Published: August 2008

The results of about 1400 pollinations that involved the 21 species of Lobelia L. sect. Lobelia are reported. The bispecific combinations that gave positive or negative results are recorded. Thirty-three different species combinations are represented in the artificial interspecific hybrid populations. Two of these hybrids have been reported by previous authors.Lobelia × rogersii hybr. nov. (L. brevifolia × L. puberula) is described. Numerous natural hybrid specimens were examined and the parentage was confirmed experimentally. Some plants of L. × rogersii were pollen-sterile; other plants were partly self-fertile.
CHROMOSOMAL ALTERNATION OF GENERATIONS IN NEREOCYSTIS LUETKEANA (MERTENS) POSTELS AND RUPRECHT
Authors: Kemp Lindley , Cole Kathleen
Published: August 2008

A cytological examination of the life history of Nereocystis luetkeana has shown that an alternating chromosome number corresponds to the morphological alternation of generations. The first division sequence of the zoosporangial nucleus is meiotic and is followed by three, usually synchronous, mitotic divisions. Thirty-two zoospores are liberated from each sporangium, and their germination gives rise to male and female gametophytes. Genotypic determination of the sexes is believed to take place in Nereocystis. Mitosis in the gametophytes is regular and cytokinesis follows each nuclear division, producing few cells in the female and many cells in the male gametophytes. Thirty-one chromosomes can be counted at the mitotic prophase. Oogamy exists in Nereocystis and fertilization takes place after the egg is extruded from the oogonium. Nuclear division in the sporophyte appears to be preceded by division of the nucleolus. Colorless and non-septate rhizoids develop as elongations of the basal cells of the sporophyte.Temperature is an important factor in the development of various stages of the life cycle of Nereocystis grown in culture, particularly in the gametophytic stage where sexual structures are produced only at temperatures less than 10 °C and vegetative growth is most prolific at 14–18 °C.Some of the unfertilized eggs develop parthenogenetically and give rise to stunted, deformed plants with multinucleate cells.
RHIZOSPHERE STUDIES IN RELATION TO VARIETAL RESISTANCE OR SUSCEPTIBILITY OF TOMATO TO VERTICILLIUM WILT
Authors: Subba-Rao N. S. , Bailey D. L.
Published: August 2008

The density of fungi in the rhizosphere and the nature of fungi on the rhizoplane of five varieties of tomato, some susceptible and some resistant to infection by Verticillium, were determined. The numbers of fungi were higher in the rhizospheres of the susceptible varieties, Bonny Best and John Baer, than in the resistant ones, Loran Blood and Moscow. However, in the rhizosphere of the resistant variety Geneva 11, the numbers of fungi did not differ appreciably from those for the susceptible varieties. Among the fungi isolated from the rhizoplane, a species of Fusarium was dominant on the varieties Bonny Best, John Baer, and Geneva 11 and Trichoderma viride Pers. was dominant on the varieties Loran Blood and Moscow. In vitro, the rhizoplane fungi did not show antagonism, either against Verticillium or amongst themselves. Nevertheless, disease intensity was reduced in vivo when roots of susceptible varieties were inoculated with Verticillium in association with Trichoderma. Verticillium grew equally well in root exudates of all the varieties. Similarly, Fusarium and Trichoderma grew well in the exudate of the susceptible Bonny Best and the resistant Geneva 11. Chromatographic analyses of root exudates of the different varieties, collected aseptically, revealed the presence or absence of several amino acids, glucose, and fructose.
TWO NEW IMPERFECT FUNGI FROM THE HEARTWOOD OF LIVING LODGEPOLE PINE
Authors: Bourchier R. J.
Published: August 2008

Two new fungi, Cephalosporium nordinii sp. nov. and Septonema chaetospira (Grove) Hughes var. pini var. nov., from the apparently normal heartwood of lodgepole pine (Pinus contorta Dougl.) are described and figured.
THE METABOLISM OF UREA AND UREIDES
Authors: Mothes K.
Published: August 2008

Urea has long been of interest to both plant and animal physiologists. As early as 1889 De Vries demonstrated by plasmolytic methods that urea permeates plant cells. Since then it has played a large part in the development of theories of permeability, and more recently a non-osmotic uptake of urea has been postulated. The evidence for this is critically considered. The main pathway of urea assimilation is considered to be through enzymic hydrolysis by urease or in some instances perhaps by an enzyme complex. Specific products of a direct urea assimilation have been sought among the ureides. While these may be present only in very low concentrations in many higher plants, in others, for example the underground parts and the stems of Borraginaceae, Plantanaceae, Hippo-castanaceae, Aceraceae, and numerous leguminous plants, they account for up to half of the total nitrogen and are important N-storage substances. The seasonal and nutritional conditions which affect the formation of several of these ureides are considered. As a third possibility of urea assimilation, the possibility is considered of the direct formation of ureides, e.g., of allantoic acid. It has been proved that higher plants are capable of degrading purines and uric acid to allantoin, allantoic acid, glyoxylic acid, and urea, but the problem remains as to whether allantoin and allantoic acid are always formed via purines.
NOTES ON THE ANATOMY OF THE GENUS ORYCTANTHUS (LORANTHACEAE)
Authors: Kuijt Job
Published: August 2008

In the taxonomically confused Loranthoideae of the Americas the genus Oryctanthus stands out as a distinctive entity. The following combination of characters is described in support of this contention:1. The genus is limited to continental parts of tropical America, with the sole exception of one species in Jamaica.2. Few epicortical roots are produced, and these at the base of the plant only.3. Stellate fiber-bundles and crystalliferous sclereids are present in foliage leaves.4. The spikes are swollen and bear sunken, sessile flowers.5. The pollen type is apparently unique in the family.
THE INCORPORATION OF C14 INTO CELLULOSE AND OTHER POLYSACCHARIDES OF SUGAR BEET LEAF DURING SHORT TERM PHOTOSYNTHESIS IN C14O2
Authors: Mortimer D. C. , Wylam Clare B.
Published: August 2008

The carbohydrates of sugar beet leaf were fractionated by successive extractions in ethanol, water, and three concentrations of potassium hydroxide. Quantitative hydrolysis of the polysaccharides from the water- and alkali-soluble fractions gave galactose, glucose, arabinose, xylose, ribose, and rhamnose in varying proportions. When these fractions from leaves which had photosynthetically assimilated C14O2 for 10 to 120 seconds were analyzed, all fractions, including the alkali-insoluble cellulose, were labelled after only 10 seconds. The proportion of C14 in the alkali-soluble fraction was high relative to that in cellulose after 10 seconds, but similar in both fractions after longer periods. All of the radioactivity in the carbohydrates was in glucose (apart from the fructose of sucrose). When photosynthesis in C14O2 was followed by photosynthetic periods in normal air, the polysaccharide fractions all continued to receive C14-labelled glucose for about 5 minutes. No significant transfer of radioactivity from one fraction to another was detected during an additional 40 minutes. The data indicate that the formation of leaf polysaccharides is closely linked to early products of the photosynthetic assimilation of carbon dioxide, and that the different polysaccharides are formed concurrently with little interconversion.
GROWTH STUDIES OF REGIONAL ISOLATES OF ECHINODONTIUM TINCTORIUM, THE INDIAN PAINT FUNGUS
Authors: Paine Lee A. , O'Regan William G.
Published: August 2008

Growth of the fungus Echinodontium linctorium, cause of an important trunk rot in true firs, was studied at various fixed temperatures in vitro. A polynomial approximation of the three-dimensional growth surface over temperature and time was developed with the aid of statistical techniques and computer facilities. The growth of isolates from northern and central Sierra Nevada forest regions of California was compared in this manner. The optimum temperature of the northern isolates was found to vary with the period of observation. For these isolates, the optimum temperature for rate of growth decreased with time, approaching a constant value. The optimum temperature of the central Sierra Nevada isolates was not found to vary with time. At near-optimum temperatures, the estimated growth rate of isolates from northern California was 75% greater at 20 days than that of the central Sierra Nevada isolates. The estimated optimum temperatures of the isolates from the two regions differed by only 1.2 °C at 20 days. Deviations of 1.2 °C from the optimum produced only slight differences in the estimated growth rate of either group of isolates. Use of the constant "terminal optimum temperature" is suggested for describing the growth response of fungi. Unlike the commonly reported "optimum temperature", the value of the terminal optimum temperature does not depend upon the period of observation.
EXUDATE PRODUCED BY GLOMERELLA CINGULATA SPORES IN THE PRESENCE OF COPPER AND DITHIOCARBAMATE IONS
Authors: Thorn G. D. , Richardson L. T.
Published: August 2008

Small amounts of copper ions induce the release from spores of Glomerella cingulata Spauld. & Schrenk. of increased amounts of amino acids, predominantly glutamic acid, α-alanine, γ-aminobutyric acid, aspartic acid, glycine, leucine(s), and serine. Sodium dimethyldithiocarbamate, and copper in the form of the dimethyldithiocarbamate complex, do not show this effect. Added protein, such as egg albumin or cellulase, or the extracellular protein of spores suspended in water, forms a soluble ternary complex with dithiocarbamate and copper ions. This results in little or no loss of dithiocarbamate from solution and in reduced toxicity in the first mode of the dosage–response curve.
THE RELATION OF BARK MOISTURE TO THE DEVELOPMENT OF CANKER DISEASES CAUSED BY NATIVE, FACULTATIVE PARASITES: VII. SOME EFFECTS OF THE SAPROPHYTES ON THE BARK OF POPLAR AND WILLOW ON THE INCIDENCE OF HYPOXYLON CANKER
Authors: Bier John E. , Rowat Marian H.
Published: August 2008

It has been shown that saprophytes were prevalent at the nodes, lenticels, and other irregularities on 1-, 2-, and 3-year-old bark of Populus trichocarpa Torrey and Gray and Salix sp. Antagonism tests demonstrated that the extracts of natural bark and two of the most common saprophytes inhibited the growth of Hypoxylon pruinatum (Klotzsch) Cke. However, the extracts of surface-sterilized bark were found to promote the cultural growth of the pathogen. No differences were observed in the behavior of the extracts obtained from dormant and actively growing bark tissues.The results of inoculation experiments demonstrated that Hypoxylon canker did not develop when the saprophytes were present on watered greenwood cuttings of black Cottonwood and willow. However, the saprophytes were not effective in preventing infection and canker growth on cuttings with below-normal levels in bark turgor. Surface-sterilized cuttings proved susceptible to the disease at all levels of bark turgor.Possible relationships between the temperature and moisture requirements of the pathogen and representative bark antagonists, and the epidemiology of canker diseases caused by facultative parasites, are discussed.
AUTOLYTIC PRODUCTION OF HYDROGEN CYANIDE BY CERTAIN SNOW MOLD FUNGI
Authors: Ward E. W. B. , Lebeau J. B.
Published: August 2008

Hydrogen cyanide production by two pathogenic isolates of an unidentified basidiomycete was studied in shake culture in synthetic and natural media. Both isolates release HCN in infected host plants but one isolate (type A) failed to produce HCN in culture. Curves for growth and HCN production by the second isolate (type B) indicated that HCN is a product of autolysis and is not dependent on the provision of specific substrates in the medium.
THE NATURE AND INHERITANCE OF A YELLOW-LEAF CHARACTER IN MEDICAGO SATIVA L.
Authors: Childers W. R.
Published: August 2008

An alfalfa mutant with yellow cotyledons and yellow leaves is described. The few seedlings that live to maturity are dwarfs. The character is determined by a single recessive gene (Xantha-1 or X1) inherited tetrasomically. A histological study of the leaf morphology indicated that the tissues of the mutant have similar structure to those of green leaves. The plastids are well formed but take up stain weakly in comparison with the plastids in normal green leaves.
RAGWEEDS, AMBROSIA SPECIES, IN CANADA AND THEIR HISTORY IN POSTGLACIAL TIME
Authors: Bassett I. J. , Terasmae J.
Published: August 2008

Specific differences of Ambrosia artemisiifolia, A. trifida, and A. coronopifolia are described and their present Canadian distributions are reported in detail. Ambrosia pollens, identified in fossil assemblages as either A. artemisiifolia or A. trifida with a few in the size range of A. coronopifolia, were somewhat more abundant in late-glacial deposits than in younger postglacial sediments except the subrecent ones. It is only within the last 200 years that ragweeds have again become abundant in eastern Canada. The migration and spread of the three ragweed species in eastern and western Canada through postglacial time are discussed. There is evidence through pollen profiles that Ambrosia species existed further northward in Ontario than they do at the present time. In studying the presence and abundance of Ambrosia pollen in surface samples, the authors showed that ragweed pollen can be transported through the atmosphere at least 375 miles from any known source.
THE EFFECT OF LIGHT QUALITY ON THE PRODUCTS OF PHOTOSYNTHESIS IN CHLORELLA VULGARIS
Authors: Hauschild A. H. W. , Nelson C. D. , Krotkov G.
Published: August 2008

Suspensions of Chlorella vulgaris, grown in synchronous culture, were pretreated in darkness for 45 to 225 minutes and illuminated in the presence of C14-bicarbonate with red, with red plus 4% of blue, and with blue light alone. The light intensities were so adjusted that the rate of photosynthesis (fixation of C14) was the same under the different conditions of illumination. The distribution of C14 among the various compounds of the ethanol-soluble fraction was obtained using paper chromatography and autoradiography.After 5 minutes of photosynthesis, the incorporation of C14 into aspartic acid was higher in the presence of red with supplementary blue light than in red light alone. At the same time the total radioactivity in glycine plus serine and in glycolic acid decreased. After 30 minutes of photosynthesis, blue light supplementary to red and blue light alone increased the total incorporation of C14 into the amino acid plus organic acid fraction as compared with incorporation in red light. This was due mainly to an increase in the radioactivity of aspartic and glutamic acids, while at the same time the radioactivity in glycine and glycolic acid was reduced.The duration of dark pretreatment was an important factor in the 30-minute experiments. The effect of increased dark pretreatment was to lower the incorporation of C14 into aspartic and glutamic acids when photosynthesis was carried out in red light, but the incorporation of C14 into these acids was increased in the presence of supplementary blue light.It is concluded that the distribution of carbon among the products of photosynthesis is affected by the quality of light.
NOTES ON FUNGI FROM NORTHERN CANADA: V. GASTEROMYCETES
Authors: Bowerman Constance A. , Groves J. Walton
Published: August 2008

Twenty-eight species of Gasteromycetes are reported from northern Canada. Two new species are described, Rhizopogon parvisporus Bowerman and Bovistella humidicola Bowerman.
STUDIES ON ASCOCHYTA IMPERFECTA PECK. FACTORS AFFECTING SPORULATION OF CANADIAN ISOLATES ON NATURAL AND ARTIFICIAL MEDIA
Authors: Mead H. W.
Published: August 2008

Pycnidia of Ascochyta imperfecta Peck are mature on alfalfa in March and April in Saskatchewan. Development, exudation, and spread of pycniospores are dependent upon moisture. Black stem, caused by this fungus, usually fails to appear in dry years until late in the season. This was very noticeable in the very dry season of 1961. Pycniospores remained viable in dry stem material up to 50 months. Pycnidia developed on synthetic media and on sweet clover stems over a range of 20° to 80° F; the optimum was 65° to 75° F. Light did not affect pycnidial formation, but relative humidity was a controlling factor. Development was profuse at 80 to 100%, but did not occur at a constant 100%. Various isolates of Ascochyta imperfecta reacted differentially to the kind and concentration of sugars, balance of sugar and nitrogen, and, in the early stages, kind of amino acids in synthetic media. The kind of nitrogen supplied was not limiting, but addition of nitrogen to the medium favored pycnidial development more than addition of sugar. The relative ability of isolates of Ascochyta imperfecta to utilize nutrients in their changing forms for production of spores is considered important in the survival of parasitic strains.
THE BIOSYNTHESIS OF INDOLEACETIC ACID IN MELAMPSORA LINI (PERS.) LEV.
Authors: Srivastava B. I. Sahai , Shaw Michael
Published: August 2008

Mycelium of Melampsora was grown on flax cotyledons in tissue cultures. Mycelium and uredospores were incubated with DL-tryptophane-2-C14 and uredospores were incubated with L-tryptophane. Acid and neutral ether-soluble and aqueous fractions of the plant material and incubation medium were chromatographed and sprayed with chromogenic agents or radioautographed. Radioactive indoleacetic acid was produced in small amounts by both mycelium and spores (yield = 0.016% in 8 hours). The auxin was identified on the basis of its Rf values in two solvent systems, its reactions with Ehrlich and Salkowski reagents, and its ability to promote extension growth of Avena coleoptiles. Evidence for the formation of indoleacetaldehyde was also obtained. Several other radioactive and Ehrlich-positive products of tryptophane metabolism were detected but not identified. One of these could have been indolepyruvic acid. Tryptamine and indoleacetonitrile were not found. The results suggest that, in Melampsora, the synthesis of indoleacetic acid from tryptophane proceeds through indolepyruvic acid and indoleacetaldehyde.
EFFECT OF WHITE, RED, AND BLUE LIGHT ON THE NATURE OF THE PRODUCTS OF PHOTOSYNTHESIS IN TOBACCO LEAVES
Authors: Tregunna E. B. , Krotkov G. , Nelson C. D.
Published: August 2008

Detached tobacco leaves were placed singly into a photosynthesis chamber and illuminated in the presence of C14O2 with white, red, or blue light. Two kinds of experiments were carried out. In the first, the energy of the three kinds of incident light was adjusted so that the rate of CO2 uptake was the same. In the second, the energy of the three kinds of incident light was the same and the time adjusted so that an equal amount of CO2 was taken up by each leaf. At the end of photosynthesis the distribution of C14 was determined in the ethanol-soluble and-insoluble fractions and among the various compounds of the ethanol-soluble fraction that were separated by paper chromatography.No effect of wavelength of light was observed on the distribution of absorbed carbon dioxide between the ethanol-soluble and -insoluble fractions. Neither was there any evidence that red light stimulated synthesis of soluble sugars. Red light, compared with white, increased incorporation of carbon dioxide into glycine, but had no effect on serine. Blue brought about a considerable decrease in glycine and some decrease in serine.A tentative explanation is given of a mechanism by means of which the wavelength of light may affect the distribution of absorbed carbon dioxide among the various photosynthetic products.
SEROLOGICAL ANALYSIS OF SOME STONE-FRUIT VIRUS ISOLATES
Authors: Tremaine J. H. , Willison R. S.
Published: August 2008

Concentrated extracts of petals from trees infected with stone-fruit virus diseases, and of cucumber plants inoculated with viruses isolated from these trees, were tested serologically by the gel-diffusion technique with antisera prepared by injection of petal and cucumber plant preparations into rabbits. An antigen, antigen Q, was detected in two yellows, latent and recurrent necrotic ring spot, two green ring mottle isolates from sour cherry, a prune dwarf isolate, two tatter leaf of sweet cherry isolates, and isolates from latent infections of plum and peach. Another antigen, the V antigen, was detected in all the isolates with the exception of a latent necrotic ring spot isolate. A third antigen, antigen P, was detected only in the two yellows, recurrent necrotic ring spot, two green ring mottle isolates from sour cherry, a prune dwarf isolate, and two tatter leaf isolates from sweet cherry. Some differences between the Q antigens in certain isolates were demonstrated, but the V antigens differed little from isolate to isolate. The recurrent necrotic ring spot isolate was shown to contain at least two distinct viruses and the P antigen was associated with one of these viruses.
FURTHER OBSERVATIONS ON CORRELATIONS AFFECTING REGENERATION IN SPLACHNUM AMPULLACEUM (L.) HEDW.
Authors: Maltzahn Kraft E. von
Published: August 2008

A leaf attached to a stem segment promotes regeneration from cells of this segment while the stem segment inhibits cellular regeneration from the leaf. The age of the gametophore is found to influence greatly stem inhibition of attached leaf regeneration. Decapitation of the gametophore prior to stem segment isolation results in increased protonematal regeneration from cells of the leaf attached to this segment. Pretreatment of the plant with various concentrations of NH4NO3 before stem segment isolation influences cellular regeneration from the attached leaf, higher non-toxic concentrations of NH4NO3 increasing the number of protonematal regenerates per attached leaf greatly.It is emphasized that one is not dealing in the present case with specific inhibitory influences from the stem segment on leaf regeneration. The present correlation system has to be interpreted, rather, in terms of the organization of the whole gametophore, and this is attempted.
CLOVER PHYLLODY VIRUS IN CANADA AND ITS TRANSMISSION
Authors: Chiykowski L. N.
Published: August 2008

Phyllody in clovers, observed on rare occasions in Canada since 1902, is now common in Quebec, New Brunswick, Nova Scotia, and Prince Edward Island. Tests in the field indicated that natural spread of the disease could occur each month from June to September. A virus causing phyllody symptoms was transmitted by the leafhoppers Macrosteles fascifrons (Stal), Aphrodes bicinctus (Schrank), and Scaphytopius acutus (Say) from Trifolium repens L. to T. repens. M. fascifrons also transmitted the virus to and from Vinca rosea L. and Callistephus chinensis Nees. S. acutus transmitted the virus to V. rosea and Trifolium pratense L. The virus was also transmitted by dodder, Cuscuta gronovii Willd., from V. rosea to V. rosea. Clover phyllody virus (CPV) in Canada resembles CPV in England and Europe and both are transmitted by A. bicinctus. Although CPV in Canada is transmitted by M. fascifrons, which is a vector of aster-yellows virus (AYV), it differs from recognized strains of AYV in other vector–virus relationships, symptomatology, and geographic distribution.
GROWTH OF KABATIELLA CAULIVORA ON DIFFERENT MEDIA
Authors: Colotelo N. , Grinchenko A. H. H.
Published: August 2008

Conidia of Kabatiella caulivora (Kirch.) Karak. were observed to develop into various forms when cultured on different media. Conidial forms appeared to fall into four main categories with each form capable of producing typical conidia. These included (a) sickle-shaped, unicellular, hyaline conidia containing from 1–8 nuclei; (b) cylindrical to clavate, one- to two-celled hyaline conidia with 5–15 nuclei per cell; (c) multicellular, light to dark green conidia containing as many as 25 nuclei in the terminal cells; (d) cylindrical, two- to five-celled, dark brown, heavy-walled conidia containing 2–4 nuclei per cell. The above conidial forms have been observed in infected plant material.
COMPARATIVE STUDIES BETWEEN THE APHID TRANSMISSION OF POTATO LEAF ROLL AND TURNIP LATENT VIRUSES
Authors: MacKinnon J. P.
Published: August 2008

Transmission of potato leaf roll and turnip latent viruses by Myzus persicae (Sulz.) were similar in that: (a) fasting aphids for 18 hours prior to inoculation feeding had no effect on the numbers that transmitted virus; (b) upper and lower surfaces of infected leaves of Physalis floridana Rydb. were equally good sources of virus; (c) top leaves of infected plants were better sources of virus than middle or bottom ones; (d) excised leaves were better sources of virus than whole plants for short acquisition feeding periods but not for longer ones; (e) when infective aphids fed on a small area of a leaf, they transmitted virus as often as those that fed on whole plants; (f) and more nymphs transmitted virus than adults.The transmission of the two viruses differed in that: (a) during comparable acquisition and inoculation feeding periods more aphids transmitted potato leaf roll than turnip latent virus; (b) fasting aphids for 18 hours prior to acquisition feeding had no effect on the numbers that transmitted potato leaf roll, but increased the numbers that transmitted turnip latent virus; (c) and three- or six-leaf P. floridana were equally good test plants for potato leaf roll, but more three-leaf ones became infected with turnip latent virus.
PECTIC ENZYME SYNTHESIS IN RELATION TO VIRULENCE IN FUSARIUM OXYSPORUM F. LYCOPERSICI (SACC.) SNYDER AND HANSEN
Authors: Paquin R. , Coulombe L. J.
Published: August 2008

The pectic enzymes produced by Fusarium oxysporum f. lycopersici appear to be causally related to the virulence of the pathogen. The effects of various cultural conditions on the synthesis of pectin methylesterase by two strains of the pathogen were investigated. The virulent strain grew better and produced more pectic enzymes than the avirulent one, and this difference became even more pronounced in media with high pectin content and when the temperature of incubation was raised from 15° to 28 °C. The correlation between the virulence of the pathogen and the production of the pectic enzymes is discussed.
FUNGI ASSOCIATED WITH FOMES IGNIARIUS VAR. POPULINUS IN LIVING POPLAR TREES AND THEIR PROBABLE SIGNIFICANCE IN DECAY
Authors: Good H. M. , Nelson Jane I.
Published: August 2008

Poplar trees with decay typical of that caused by Fomes igniarius, or with extensive stain, were dissected and several hundred platings made from each. Sixty-three different fungi were isolated, as many as 20 from a single tree. Most of the fungi were widely distributed in the tree with no consistent association with any stage of decay. Different zones of decay yielded 19 to 36 fungi each, the zone of early incipient decay giving the largest number. Bacteria were isolated from every zone.Trees with stain but no decay yielded 24 fungi, 15 of which were also found in the decayed trees. Many of these were clearly precursors of F. igniarius. Several pockets of typical decay did not yield F. igniarius, suggesting that it had been killed out by competition.The pH of water extracts of wood from various zones of decay was highly variable, the minimum range for a zone being pH 4.8 to pH 8.8, and the maximum range pH 3.8 to pH 9.4. The implications of these variations are discussed.Effects of various media, and of frozen storage prior to making isolations, were studied.
STUDIES ON RUBUS VIRUS DISEASES IN BRITISH COLUMBIA: VIII. RASPBERRY LEAF CURL
Authors: Stace-Smith Richard
Published: August 2008

A virus disease that occurs on red raspberry in the Okanagan Valley in British Columbia was identified as raspberry leaf curl. Under experimental conditions the virus was transmitted by the aphid Aphis idaci V. d.G. Test plants included red raspberry, Rubus idaeus L.; black raspberry, Rubus occidentalis L.; wineberry, Rubus phoenicolasius Maxim.; Rubus henryi Hemsl. & Kuntse; and the Alpine strawberry, Fragaria vesca L. The virus did not infect black raspberry and caused only transitory symptoms on Alpine strawberry. Root cuttings of red raspberry, leaf-bud cuttings of R. henryi, and seedlings of wineberry provided satisfactory indicator plants. Wineberry and R. henryi were more readily inoculated by aphids than red raspberry. Non-viruliferous aphids required a feed of at least 1 day on the virus source to acquire an infective charge. When viruliferous aphids were transferred to a series of healthy indicator plants, some plants became infected after a test access time of 20 minutes, although transmissions were increased if the time was increased to 1 hour. The virus was found to persist in viruliferous aphids for at least 11 days. Leaf curl virus was not eliminated from infected plants held at an air temperature of 37 °C for periods up to 4 weeks.
APICAL AND RADIAL GROWTH OF WHITE SPRUCE (PICEA GLAUCA (MOENCH) VOSS) AT CHALK RIVER, ONTARIO, CANADA
Authors: Fraser D. A.
Published: August 2008

Apical and radial growth, and the developmental anatomy of vegetative and reproductive buds of Picea glauca, were investigated. Apical growth of the leader occurred from mid-May until mid-July, that of the side branches from mid-May until late June or early July. Total apical growth of the side branches, in general, diminished with their distance from the leader. Initiation of radial growth started in the main axis behind the terminal bud and moved basipetally along the trunk. Cessation of radial growth followed the same order.The apex of the vegetative bud developed in late July or early August includes a central zone, a peripheral zone with needle primordia, and a basal zone of thick-walled cells. Reproductive buds could be recognized by early August as oblong structures with globose appendages. By mid-August, these appendages had differentiated into either pollen sacs with pollen mother cells in the male buds, or into bracts and ovuliferous scales in the female ones. The female cone entered winter with little visible internal differentiation. The influence of temperature fluctuations on vegetative and reproductive growth is discussed.
A STUDY OF PHENOLIC COMPOUNDS IN IMPATIENS
Authors: Bohm B. A. , Towers G. H. N.
Published: August 2008

The phenolic acid pattern of 17 species of Impatiens is presented. The presence of naphthoquinone derivatives in four new species is reported. A discussion of some prominent unidentified phenolic compounds on two-directional chromatograms is presented which includes discussion of possible forms in which naphthoquinones may exist in the living plant. The identification of scopoletin (6-hydroxy-7-methoxycoumarin) in several species studied marks the first report of this compound in the Balsaminaceae.
THE LEPTOGRAPHIUM COMPLEX VERTICICLADIELLA HUGHES
Authors: Kendrick W. Bryce
Published: August 2008

The type species of the generic name Verticicladiella Hughes, V. abietina (Peck) Hughes, is illustrated and redescribed. Six other species, four of which are new, are also included in this genus of hyphomycetes, which is distinguished from Leptographium by its different method of conidium development. Species of Verticicladiella are usually collected on, or isolated from, wood of conifers, and are often associated with bark-beetle attacks and blue stain. One of the new species secretes an antibiotic substance, and another causes a severe root disease in some species of Pinus in the southwestern United States.