bluuebunny/crossref_metadata_2025 huggingface dataset:
ÉTUDES SUR LE GENRE SOLIDAGO L. : II. LA MISE EN ÉVIDENCE DE LA POLYPLOÏDIE ENDOTAXONIQUE CHEZ S. PURSHII PORTER ET LES TAXA SIMILAIRES
Authors: Beaudry Jean R. , Zinger Alexis , Saint-Pierre Jacques
Published: August 2008

In Solidago Purshii Porter, there are two cytodemes, one diploid (2n = 18) and the other tetraploid (2n = 36), which can be distinguished on the basis of the length of the guard cells of their leaf stomata. The diploid plants possess guard cells which are smaller than those of the tetraploid. These two entities of S. Purshii thus belong to the groups of cytodemes in which there exists a positive correlation between the chromosome numbers and the dimensions of certain quantitative morphological characters, such as the length of the guard cells.In groups in which the variation curves of the characters of the different cytodemes overlap little or not, the geographical distribution of the different cytodemes of the complex may be studied much more easily, rapidly, and comprehensively by measuring the length of the guard cells of herbarium specimens than by making chromosome number determinations. The data presented indicate that when sampling is made under the conditions described in this paper, determinations of the length of two guard cells of stomata of one mid-leaf per individual, made on two individuals per colony, is satisfactory for that purpose, on the average. However, it is recommended, as a safeguard, to increase these figures by a few units, and to make always a few direct chromosome number determinations to check the accuracy of this rapid technique. These direct determinations may also be necessary to know the chromosome numbers of certain extreme individuals of the different cytodemes which have guard cells that differ little in length.
THE EFFECT OF PRATYLENCHUS PENETRANS ON A CLONE OF FRAGARIA VESCA
Authors: Townshend J. L.
Published: August 2008

The effect of Pratylenchus penetrans (Cobb, 1917) Sher & Allen, 1953 on a clone of Fragaria vesca was investigated. In the presence of small numbers of P. penetrans, the net increase in the number of petioles, petiole length, and fresh weight was significantly less than that of the controls. It would appear by analogy that P. penetrans may well be an important primary parasite in the strawberry root-rot complex.
FURTHER EVIDENCE FOR THE VALIDITY OF THE DEGRADATION OF C14-LABELLED ASPARTIC ACID ISOLATED FROM DETACHED LEAVES
Authors: Nelson C. D.
Published: August 2008

not available
REVISIONES HYPHOMYCETUM ALIQUOT CUM APPENDICE DE NOMINIBUS REJICIENDIS
Authors: Hughes S. J.
Published: August 2008

Nearly 400 generic names and 1000 species names of microfungi, mostly Hyphomycetes, have been checked from the original publications. Access to type or authenticated material of most of them has resulted in some revisions. Seven generic names and 22 species names are shown to be nomina dubia or nomina confusa.
SOME FOLIICOLOUS FUNGI OF THE PYROLACEAE
Authors: Parmelee J. A.
Published: August 2008

This paper presents a review of some of the fungi that parasitize hosts in the Pyrolaceae. Lophodermium pyrolae Parmelee on Pyrola spp. and Strasseria nigra Dearn. on Pyrola spp. are described as new. Mycosphaerella chimaphilae (Ell. & Ev.) Hoehn. is considered to be synonymous with Mycosphaerella chimaphilina (Pk. in Sacc.) House. Ovularia pyrolae Trel. is transferred to the genus Colletotrichum and new hosts and range extensions are listed for other fungi.
CULTURAL VARIATION IN MYCOSPHAERELLA FRAGARIAE
Authors: Bolton A.T.
Published: August 2008

Mycosphaerella fragariae (Tul.) Lindau isolated from several commercial strawberry varieties in different localities varied in cultural characteristics. Each strawberry variety gave rise to a more or less distinct cultural type. Twenty-five cultural types were recognized. Variations were also found among isolates from native F. virginiana in different areas. These variations included differences in colony color, pigment production, rate of growth, topography of colony, and rate of conidial production.Some isolates produced variants in culture on artificial media. Differences in stability were exhibited by different types. Variations or mutations were detected in two cultural types after they had passed five times through hosts other than those from which they were originally isolated.It is postulated that the possible number of distinguishable types of M. fragariae occurring in nature is infinite, being limited only by the possible number of genetic variations in the host itself.
STUDIES ON SLIME ACCUMULATIONS IN PULP AND PAPER MILLS: I. SOME FUNGI ISOLATED FROM MILLS IN NEW BRUNSWICK AND NEWFOUNDLAND
Authors: Brewer D.
Published: August 2008

The following fungi have been isolated from samples of slime from mills in New Brunswick and Newfoundland: Phialophora fastigiata, P. richardsiae, P. lignicola, P. alba, Truncatella ramulosa, Trichoderma lignorum, Pseudeurotium zonatum, Geotrichum candidum, Rhinocladiella atrovirens, Pachybasium candidum var. trichodermatoides, Pachybasium niveum.
THE ACTION OF DISODIUM VERSENATE ON THE EPIDERMAL CELLS OF LIVING BRASSICA ROOTS
Authors: Cormack R. G. H.
Published: August 2008

This paper describes the action of the metal-chelating reagent disodium versenate on the epidermis of living Brassica seedlings. Striking abnormalities were produced, characterized by the repression of root-hair formation and by swelling and deformity of the epidermal cells. The results of the present study are briefly discussed in the light of evidence obtained by use of the electron microscope.
THE FUNGICIDAL ACTIVITY OF METHYL BROMIDE
Authors: Munnecke D. E. , Ludwig R. A. , Sampson R. E.
Published: August 2008

Spores of Alternaria solani carried on glass fiber filter disks were employed in a study of the fungicidal activity of the fumigant, methyl bromide. Following exposure to the fumigant the disks, carrying the spores, were placed in a spore germination medium and the results subsequently evaluated by direct mortality counts. Linear probit-log dose regression lines were obtained by this procedure. The effectiveness of the fumigant was found to be dependent on the vapor pressure of water in the atmosphere and to be independent of temperature. The results suggest that humidity operates through its effect on spore hydration.
STUDIES OF WESTERN TREE RUSTS: IV. UREDINOPSIS HASHIOKAI AND U. PTERIDIS CAUSING PERENNIAL NEEDLE RUST OF FIR
Authors: Ziller W. G.
Published: August 2008

Observations in the field and the results of inoculation experiments show that perennial needle rust of fir (Abies spp.), known as Peridermium pseudo-balsameum (Diet. & Holw.) Arth. & Kern, is caused by Uredinopsis hashiokai Hirats. f. and U. pteridis Diet. & Holw. (U. macrosperma Magn.), which complete their life cycles on bracken fern (Pteridium aquilinum (L.) Kühn var. lanuginosum (Bong.) Fern.). The pycnial and aecial states of Uredinopsis hashiokai are described, and for the first time the life histories of U. hashiokai and U. pteridis are presented. The two species are indistinguishable from each other in life history, host relationship, and morphology of most of the spore states; they differ from each other in their geographical distribution and in the morphology of their urediniospores. It remains unknown which of the two species of Uredinopsis represents the perfect state of Peridermium pseudo-balsameum. Uredinopsis aspera Faull proved to be a later synonym of U. hashiokai. U. hashiokai is noteworthy because of its similarity to U. pteridis, and both species are unusual in development of their spore states on fir, particularly in the long periods required for maturation of the aecia, which are produced from localized, perennial mycelium 4 to 11 months after infection in Abies lasiocarpa (Hook.) Nutt. and A. grandis (Dougl.) Lindl. respectively.
STUDIES OF WESTERN TREE RUSTS: V. THE RUSTS OF HEMLOCK AND FIR CAUSED BY MELAMPSORA EPITEA
Authors: Ziller W. G.
Published: August 2008

Results from inoculation experiments have shown that the needle rust of hemlock (Tsuga spp.), Caeoma dubium C. A. Ludwig, represents the aecial state of a new race of Melampsora epitea Thuem. for which the name M. epitea f. sp. tsugae f. sp. nov. is proposed. This race differs morphologically from most species of Melampsora and from some races of M. epitea. It is indistinguishable, however, from the fir rust M. abieti-capraearum Tub. (another race of M. epitea), from which it differs in its aecial hosts only. An account of the taxonomy, morphology, and life history of M. epitea f. sp. tsugae is presented for the first time.
STUDIES IN THE GENUS LOTUS (LEGUMINOSAE): I. LIMITS AND SUBDIVISIONS OF THE GENUS
Authors: Callen E. O.
Published: August 2008

The genus Lotus (Leguminosae) is defined as including Tetragonolobus Scop. of the Old World and Hosackia Dougl. of N. America, but Dorycnium Vill. and Bonjeania Reichb. are rejected. There is no single character common to all N. American species which would justify retaining Hosackia as a separate genus. Four subgenera are proposed: 1. Pedrosia (Lowe) Brand, 2. Edentolotus Brand, 3. Deflectostylus Callen subgen. nov., and 4. Tetragonolobus (Scop.) Callen, using characters of the style (other than size) in separating them. On this basis, approximately half the N. American species fall into subgenus 2, the rest into subgenus 3.
CHROMOSOME MORPHOLOGY IN THE GENUS AVENA
Authors: Rajhathy T. , Morrison J. W.
Published: August 2008

The chromosomes of the Avena species were studied and their karyotypes established. The karyotype of the diploid species (excluding A. longiglumis) is designated as A. Longiglumis has a different karyotype with at least three chromosomes that have major changes. This karyotype is a modified A, designated as A′. The designation of the tetraploid karyotype is AB, including the basic set of chromosomes A and a second completely different set B. In the hexaploid species the basic set A is present but the B set is not; therefore the proposed designation is ACD. These results indicate an alloploid origin for the polyploid species.
GROWTH AND METABOLISM OF ASPERGILLUS NIDULANS EIDAM IN SURFACE CULTURE
Authors: Naguib Kaiser
Published: August 2008

Aspergillus nidulans was grown on glucose, fructose, sucrose, or maltose in a high-sugar medium favorable for fat formation. Glucose was more readily metabolized than the other sugars, giving a heavy felt with the highest fat content in a shorter time. Sucrose was inverted before absorption and was more conducive to growth than to fat formation. Maltose was probably absorbed after hydrolysis. It gave a heavy felt and a high fat yield but after a longer period of incubation than with glucose. Maltose metabolism was marked by lower nitrogen utilization. Hence, the maltose-fed mycelial felts had the highest carbohydrate content and the lowest protein content.Growth proceeded as long as there was available sugar in the culture medium. Extracellular nitrogenous compounds appeared in the culture media before the complete exhaustion of the sugar in some cases, providing evidence that this process is not purely autolytic in nature. The early growth phase on the different sugars was characterized by low-fat, high-protein mycelial felts. Active fat formation was found to start after the drop of the nitrogen content of the medium to a very low level. The inverse relationship between fat and protein contents in the mycelium was traced during growth on glucose, sucrose, or maltose at different stages of growth. On fructose, except for the early growth period, fat and protein syntheses proceeded proportionally.
CYTOGENETICS OF SOLID STEM IN COMMON WHEAT: II. STEM SOLIDNESS OF MONOSOMIC LINES OF THE VARIETY S-615
Authors: Larson Ruby I. , MacDonald M. D.
Published: August 2008

Lines of a variety of common wheat, S-615, monosomic for chromosomes III and XVI of homoeologous group 3 had culms less solid in the top internode than normal S-615. Monosomics of homoeologous group 5, namely, V, IX, and XVIII, were less solid in the bottom four internodes than S-615. These five chromosomes carry genes for solid stem in this variety. Monosomics XIX, XX, and XXI, the D-genome chromosomes of homoeologous groups 6, 2, and 7 respectively, were more solid than the normal check in both top and lower internodes, indicating that the missing chromosomes carry genes for hollow stem. Chromosome XIII, a homoeologue of XX, which in Chinese Spring has a gene for hollow stem, does not affect the amount of pith in the culm of S-615.The concept of the culm phenotype in a given environment resulting from an interaction of genes promoting pith development and those opposing it makes it possible to reconcile results of genetic experiments on solid stem in wheat that previously appeared contradictory.
CYTOGENETIC STUDIES IN AMARANTHUS: I. CYTOLOGICAL ASPECTS OF SEX DETERMINATION IN DIOECIOUS SPECIES
Authors: Grant William F.
Published: August 2008

Cytological observations are contained in this report on four dioecious species of Amaranthns, two of which were formerly included in the genus Acnida. The species studied are A. arenicola, A. palmeri, A. tamariscinus, and A. tuberculatus. Three of these species have a diploid chromosome number of 32, whereas A. palmeri has a somatic chromosome number of 34. A single spontaneous triploid (2n = 48) female plant was found in collections of A. tamariscinus and a tetraploid (2n = 64) male plant in collections of A. tuberculatus. A fifth species, A. australis, has previously been reported as having 32 somatic chromosomes. The chromosome numbers for half the dioecious species of Amaranthus have now been determined. Detailed observations on the dividing chromosomes of these species in mitosis, in meiosis, and in the first division of the nucleus in the pollen grain have been made and have failed to distinguish heteromorphic chromosomes which might be associated with sex determination. The small size of the chromosomes has made detailed morphological studies impractical and there is no marked difference in absolute size of the chromosomes between species. Since haploid numbers of 16 and 17 are found in both monoecious and dioecious species, it would seem that the aneuploid condition in Amaranthus arose early and hybridization within the genus has resulted in promoting the genie condition which has been necessary for the expression of the dioecious condition.
SPECIES OF LEPTOTHYRIUM AND KABATIA ON LONICERA
Authors: Conners I. L.
Published: August 2008

A comparative study of specimens in several herbaria has revealed that the species of Leptothyrium and Kabatia already reported on Lonicera fall naturally into several well-marked varieties, each of which is confined to one or a few hosts. Three new combinations, Leptothyrium periclymeni var. xylostei, Kabatia lonicerae var. americana, and K. lonicerae var. latemarensis, are made and two new varieties, K. lonicerae var. involucratae and K. mirabilis var. oblongifoliae, are described. Leptothyrium periclymeni attacks a limited number of hosts, which, however, occur in both subgenera of Lonicera whereas the Kabatia species parasitize hosts belonging to a section of one subgenus.
PHYSIOLOGICAL CONTROL OF THE DISTRIBUTION OF TRANSLOCATED AMINO ACIDS AND AMIDES IN YOUNG SOYBEAN PLANTS
Authors: Nelson C. D. , Gorham Paul R.
Published: August 2008

Each of 10 C14-labelled amino acids or amides was introduced into young soybean plants through the cut petiole of one primary leaf. The compounds used were asparagine, glutamine, urea, aspartic acid, glutamic acid, glycine, serine, alanine, norleucine, and arginine. The rates of uptake of all the solutions except arginine were in the range 1.0 to 1.5 μl per minute. After 1 to 5 minutes, the distribution of C14 throughout the plants was determined. Each amino acid was translocated as such without conversion to other compounds. From the point of introduction, translocation of each amino acid or amide was mainly downward toward the root; very little was translocated upward. The amount of asparagine or glutamine that was translocated into the primary leaf opposite the cut petiole increased as the leaf aged, while the amount of the other eight compounds decreased as the leaf aged. When asparagine and serine were administered together, serine moved into the young primary leaf while asparagine was excluded. Both excision of the roots and chilling the roots decreased the velocity of downward translocation of aspartic acid indicating that the roots exert a strong "demand" which favors translocation in a downward direction more than an upward direction in the stem.
THE PEACH REPLANT PROBLEM IN ONTARIO: VII. THE PATHOGENICITY OF PRATYLENCHUS PENETRANS (COBB, 1917) FILIP. & STEK. 1941
Authors: Mountain W. B. , Patrick Z. A.
Published: August 2008

Experiments were carried out to determine the role of Pratylenchus penetrans (Cobb, 1917) Filip. & Stek. 1941 in the peach replant problem. It is shown that this nematode is a true plant pathogen since it invades and causes necrosis of peach roots in the absence of bacteria and fungi. Necrosis of the root tissue occurs rapidly and appears to take place in advance of the invading nematode. The main mechanism involved in the formation of the lesion is the production of phytotoxic substances through hydrolysis of the cyanophoric β-glucoside, amygdalin. P. penetrans is capable of hydrolyzing this substance in vitro. It is concluded that, although P. penetrans is the most important primary parasite and a true plant pathogen, its main role in peach replant failure appears to be its ability to incite root degeneration by providing extensive infection courts for soil microorganisms.
STUDIES ON SLIME ACCUMULATIONS IN PULP AND PAPER MILLS: III. THE STIMULATION OF GROWTH BY "WHITE WATER
Authors: Brewer D.
Published: August 2008

In a basal medium which supported good growth of two species of fungi, incorporation of "white water" was found to increase their rate of growth. Preliminary efforts to separate the active agent have been carried out, and the presence of at least two substances has been demonstrated. One of them stimulated the growth of an isolate of Phialophora fastigiata, whilst the other stimulated the growth of an isolate of Phoma sp. The implications of the presence of these two substances in "white water" are considered.
INFLUENCE OF GIBBERELLIC ACID ON THE BREAKDOWN OF NICOTINE IN TOBACCO
Authors: Parups E. V.
Published: August 2008

Detached leaves, leaf disks, and sterile, detached roots of tobacco were sprayed, vacuum-infiltrated, incubated, or treated with gibberellic acid to test the influence of this chemical on the breakdown of nicotine. No statistically significant differences in nicotine content were observed due to these treatments.
CYTOGENETIC STUDIES IN THE GENUS HORDEUM: I. CHROMOSOME MORPHOLOGY
Authors: Morrison J. W.
Published: August 2008

The morphology of the chromosomes of 16 Hordeum species was studied in considerable detail. No obvious trend in evolution is apparent from a study of the karyotypes of the species nor are any definite relationships with common barley (H. vulgare) indicated, except for two species, usually considered as being related, H. spontaneum and H. agriocrithon. On the basis of similarities of karyotype and morphological features of the plants seven groups were formed in which relationships are evident. The groups are: vulgare, marinum, murinum, californicum, stenostachys-pusillum, bulbosum, and jubatum. The plants within each group are identified by assigned numbers and by the specific names under which they were received. Within these groups are chromosome numbers of 14 and 28 and in one case 28 and 42. Allopolyploidy is indicated for most groups but H. bulbosum exists both as a diploid and as an autotetraploid.
DISCUSSION: THE POSTGLACIAL DEVELOPMENT OF THE FLORA OF MANITOBA
Authors: Löve Doris
Published: August 2008

An attempt is made to establish the development of the flora of Manitoba, Canada, after the complete extermination by the Wisconsin glacier of any preexisting vegetation.Based upon geology, palynology, and floristics, a theory is constructed that the ice was at first followed by a cold (marsh) grassland, covering the bottom of the drained Lake Agassiz I, and a riverine spruce (–pine) parkland of western origin, which persisted throughout the Valders period and the damming up of Lake Agassiz II. Around 9000 B.P. a deciduous forest flora started to fill in around the edges of Lake Agassiz II, and a pine–oak savanna occupied the drier portions of the upland. This flora reached its maximum north- and westwards distribution towards the peak of the Hypsithermal. Also during the Hypsithermal it is suggested that a western (–southwestern) prairie flora covered the bottom of the draining Lake Agassiz II, reaching its farthest extension towards the north and east. During the same time, the Arctic flora expanded over the Hudson's Bay Lowland. The last part to be covered by vegetation seems to have been the zone now called taiga, probably as late as 3000–4000 years ago. The spruce forest and its undervegetation seems to have arrived both from the west and from the east, and in recent times (from 2000 to 3000 B.P.) is in a stage of expansion, forcing itself into the deciduous zone, which in turn is expanding over the prairie, save for the checking activities of Man (fire and cultivation).
GENERATIVE CYCLES OF PROTEIN AND TRANSAMINASE IN THE GROWING CORN RADICLE
Authors: Cook F. S.
Published: August 2008

Measurements have been made of growth rates, cell numbers, fresh and dry weights, protein and soluble nitrogen levels, and glutamic–aspartic transaminase activity in six successive 2 mm segments of the radicles of 3-day-old corn seedlings. The measured quantities of protein and enzyme activity are related to the stage of average cellular development, to a linear distance scale along the axis of the radicle, and to the time scale. Increments per cell per hour during cell growth are therefore computed. An attempt is made to explain the significance of the genesis of the transaminase in the growth and development of the radicle cells, to the concurrent genesis of total and specific protein, and to other generative cycles.
THE TAXONOMY AND NOMENCLATURE OF THE WHEATS, BARLEYS, AND RYES AND THEIR WILD RELATIVES
Authors: Bowden Wray M.
Published: August 2008

The correct name for the tribe that contains the wheats, barleys, and ryes and their wild relatives is TRITICEAE Dumort. The genus Triticum L. emend. is treated to include both the diploid, allotetraploid, and allohexaploid wheats (Triticum L.), and the diploid species and the allotetraploid and allohexaploid species of interspecific hybrid origin that were formerly placed in the genus Aegilops L. In the geuus Triticum L. emend., there are 10 diploid species; one allotetraploid wheat species of hybrid origin (T. turgidum L. emend.) which includes many cultivars, three botanical varieties, and one auto-allohexaploid form; one allohexaploid wheat (T. × aestivum L. emend.) which is a hybrid complex that includes many cultivars; 10 other allotetraploid or allohexaploid species of interspecific hybrid origin; and numerous other artificial and natural interspecific hybrids. Section HORDEUM of the genus Hordeum L. contains the cultivated barleys and their wild relatives which are all classified under one species, H. vulgare L. emend. The taxonomy of the ryes and the genus Secale L. is considered briefly.
PALAEOBOTANICAL STUDY OF BURIED PEAT FROM THE MACKENZIE RIVER DELTA AREA, NORTHWEST TERRITORIES
Authors: Terasmae J.
Published: August 2008

A palaeobotanical and palynological study of samples of buried peat from the MacKenzie River delta area, Northwest Territories, has shown that the peat accumulated during an interglacial interval. For reference purposes a study of modern pollen of Rubus chamaemorus L. and of four species of Drosera L. has been made.
THE DETERMINATION OF K-CARRAGEENIN AS A FACTOR IN THE CLASSIFICATION OF THE RHODOPHYCEAE
Authors: Yaphe W.
Published: August 2008

Aqueous extracts from 30 species of red algae were treated with κ-carrageenase, a specific hydrolase for κ-carrageenin. The total reducing power of the hydrolyzate indicated that the algae could be divided into three groups on the basis of the content of κ-carrageenin. Group 1 included Gigartina acicularis, G. radula, G. pistillata, G. christata, and Iridaea sp. with a low value. Group 2 included Chondrus crispus, G. stellata, G. stiriata, Rhodoglossum affine, Furcellaria fastigiata, and Endocladia muricata, all with values comparable with that in C. crispus. Group 3 included Hypnea musciformis and a Yatabella sp. with a value greater than that for C. crispus. The occurrence of agarose and of κ-carrageenin in the Rhodophyceae is discussed as a factor in their taxonomy.
DISSEMINATION OF VERTICILLIUM ALBO-ATRUM ON SEED OF SUNFLOWER (HELIANTHUS ANNUUS)
Authors: Sackston W. E. , Martens J. W.
Published: August 2008

Sunflower seed harvested from diseased plants in a Verticillium nursery in Manitoba, surface-sterilized and plated on potato sucrose agar, gave rise to colonies of Verticillium albo-atrum Reinke and Berth. Microsclerotia of the organism were confined to the hull and testa of the infested seeds. The fungus was not found in any portion of the seed inside the testa. Approximately 50 per cent of the infested seeds germinated on the agar plates; the rest apparently were dead. Symptoms typical of Verticillium infection developed in sunflower plants in a plot on clean soil sown with seed harvested from diseased plants in a Verticillium nursery. No diseased plants were found in adjacent plots sown with seed from healthy plants.Failure to isolate the pathogen from seed taken from typically diseased plants in a farm field near the Verticillium nursery may signify that seed infestation occurs only under favorable circumstances. The factors predisposing to such infestation are not yet known. Lack of consistency in isolation of the pathogen from seed taken from diseased plants from various sources parallels the contradictory results obtained by workers studying seed dissemination of V. albo-atrum in other crops.
SALTATION AND ZONATION FORMATION IN VERTICILLIUM LATERITIUM
Authors: Isaac Ivor , Abraham G. H.
Published: August 2008

In a study of the non-sporulating hyaline saltants of Verticillium lateritium it was found that the incidence of saltation in subcultures increased as the parent stock cultures became more aged. The factor (factors) responsible for this resided not in the spores but in the hyphae and it (they) was (were) probably water soluble because washing in distilled water appeared to rid the inoculum of any tendency to cause saltation.Three types of concentric zonations were observed in cultures of V. lateritium: (a) those produced by stimulation to sporulation due to the action of light of a specific intensity, period, and wave length, following a dark period in excess of a minimum of 9 hours; (b) those caused by zones of reduced sporulation occurring as a result of poor mycelial development resulting from temperature changes above or below the optimum for growth; (c) those formed in a saturated atmosphere where a physical collapse of some of the conidiophores in the center of the colony occurred due probably to excessive condensation. Variations in the humidity of the atmosphere caused neither stimulation nor inhibition to sporulation.
PALAEOBOTANICAL STUDY OF LATE-GLACIAL DEPOSITS FROM VANCOUVER ISLAND, BRITISH COLUMBIA
Authors: Terasmae J. , Fyles J. G.
Published: August 2008

Plant-bearing beds have been discovered by J. G. Fyles in late-glacial deposits from the Englishman River section, Vancouver Island, B.C. Radiocarbon dating indicated an age of ca. 12,000 years for these beds. Fossil cones of Pinus contoria Dougl. and leaves of Dryas drummondii Richards, were discovered and identified. Palynological study indicates that climate at the time was colder than the present.
THE STRUCTURE AND MANNER OF DIVISION OF THE NUCLEI IN THE VEGETATIVE MYCELIUM OF THE BASIDIOMYCETE SCHIZOPHYLLUM COMMUNE
Authors: Bakerspigel A.
Published: August 2008

The nuclei in the vegetative hyphae of Schizophyllum commune do not divide in a manner directly comparable to ordinary mitosis. During division the tightly packed chromatinic granules become loosely arranged following which they contract into a densely stained bar. As division proceeds this bar of chromatin elongates and then constricts at its mid-region. At the end of division the extremities pull apart quickly to form the chromatin portions of the two sister nuclei. The Feulgen-negative central bodies decrease in size and at the end of division their remnants lie free in the cytoplasm. New central bodies arise in the maturing sister nuclei. Throughout division metaphase plates, spindles, or individual chromosomes were not observed in any of the stained or living preparations. A nuclear membrane has not been observed surrounding any of these nuclei.
NUCLEAR BEHAVIOR IN THE DIPLOIDIZATION OF HAPLOID INFECTIONS OF PUCCINIA HELIANTHI
Authors: Craigie J. H.
Published: August 2008

Nuclei of Puccinia helianthi occur in two principal but dissimilar states: an expanded one, characteristic of resting nuclei, and an unexpanded one associated with the process of division. Transitional stages intervene. Preliminary to division, the resting nucleus extrudes its nucleolus and contracts to an unexpanded state. Division gives rise to unexpanded daughter nuclei that in the living thallus soon undergo expansion. The nuclei of germinating urediniospores conform to this general pattern. Pycniospore nuclei, though daughter nuclei, fail to expand because of their isolation. When, however, through fusions of pyeniospores and flexuous hyphae they gain access to compatible haploid mycelia, they assume an expanded form. As expanded nuclei they then continue their migration to the basal region of the protoaecia, dividing perhaps but rarely on their way. There, by rapid successive divisions, they provide nuclei of pycniospore origin for the diploidization of the protoaecia. Cells of the intercellular mycelia remain uninucleate.
MICROFUNGI: IV. TRICHOCLADIUM CANADENSE N. SP.
Authors: Hughes S. J.
Published: August 2008

Trichocladium canadense n. sp. is described from 20 Canadian isolations made from wood of sugar maple, yellow birch, beech, trembling aspen, and western hemlock.
EFFETS DE L'ACIDE GIBBERELLIQUE SUR LE MÉTABOLISME DES PLANTES
Authors: Coulombe Louis-J. , Paquin Roger
Published: August 2008

not available
DIAGNOSIS OF POTATO VIRUS F BY MEANS OF SOLANUM MINIATUM
Authors: Munro James
Published: August 2008

The reactions of certain solanaceous species to infection with potato virus F are described. Many species either do not show symptoms or are erratic in their behavior. Solanum miniatum Bernh. is a reliable specific plant indicator of this virus, unaffected by the changing environmental conditions that seem to be responsible for the varying symptom development in other species. The symptoms caused in S. miniatum by virus F are much more severe than, and quite dissimilar from, those caused in this plant by the common potato viruses A, X, and Y.
CUCUMBER NECROSIS VIRUS
Authors: McKeen Colin D.
Published: August 2008

Cucumber necrosis virus (CNV) has been isolated several times during the last 7 years from cucumbers grown under glass in southwestern Ontario. Cucumber is the only host known to be systemically infected by the virus. Although CNV exhibits many properties of viruses included in the tobacco necrosis (TNV) group, it is considered to be sufficiently different to warrant the above distinctive designation.CNV possesses a small thermal coefficient, a thermal inactivation point between 75 and 80 °C, and a dilution end point between 10−4 and 10−5.During the short-day season of greenhouse production of cucumbers the virus causes severe foliar symptoms. Serious stunting of growth occurs and infected plants usually die 6 weeks to 2 months after the virus becomes systemic. In natural infections CNV enters by way of the roots, and subsequently may invade the aerial organs. Wide variability in the upward movement of the virus from inoculated cotyledons and roots of cucumber plants of the same age is noted.In inoculated unifoliate leaves of cowpea and French bean CNV displays a lower invasive capacity than TNV. With serial transfers of juice from cowpea leaves, inoculated initially with both viruses, TNV soon predominates.
A ROOT AND STALK ROT OF SOYBEANS CAUSED BY PHYTOPHTHORA MEGASPERMA DRECHSLER VAR. SOJAE VAR. NOV.
Authors: Hildebrand A. A.
Published: August 2008

Since 1954, a destructive root and stalk rot of soybeans, identical with one reported from several of the soybean-growing areas in the United States, has been prevalent in southwestern Ontario. It is proposed that Phytophthora megasperma Drechsler var. sojae nov. var. replace P. cactorum (Lib. and Cohn) Schroet., and P. sojae Kaufmann and Gerdemann, as the more correct taxonomic designation of the causal fungus. P. megasperma var. sojae comprises strains which though indistinguishable morphologically, differ physiologically and pathologically. Artificial inoculation of varieties and of breeding lines and selections of soybeans with the causal fungus, chiefly by the highly reliable toothpick method, indicated two well-defined types of disease reaction, resistance and susceptibility. Harosoy, the variety which currently is grown most extensively in Ontario, is highly susceptible to the disease. Pathogenicity trials involving many possible wild and cultivated hosts emphasized the marked specificity of P. megasperma var. sojae to Glycine max L. Merrill. The soybean Phytophthora, having been called P. cactorum and thereby associated nomenclaturally with a representative of that species causing a root rot of sweet clover in Ontario, was found to be quite different from the sweet clover pathogen.
THE BIO-ELECTRIC POTENTIALS OF PLANTS AND THEIR FUNCTIONAL SIGNIFICANCE: III. THE PRODUCTION OF CONTINUOUS POTENTIALS ACROSS MEMBRANES IN PLANT TISSUE BY THE CIRCULATION OF THE HYDROGEN ION
Authors: Fensom D. S.
Published: August 2008

Of the three types of membranes which occur generally in plant cells, lipoid, protein, and cellulose, it would seem that a protein-coated grid of cellulose can be envisaged as surrounding the cells. Such a membrane would appear to have the right pore size and properties to allow almost unfettered hydrogen ion diffusion but yet permit intercell biopotentials to be built up. It is pointed out that the most important ion involved in diffusion and in subsequent ion exchange would seem to be the hydrogen (as hydronium) ion, and that tissue can conveniently be divided into general areas of hydrogen ion production or hydrogen ion absorption. The resulting circulation of this ion is explored and discussed in relation to photosynthesis, respiration, protoplasmic streaming, and transport. These ideas are shown to give reasonable explanations for the results obtained in experiments and to resolve certain difficulties related to biopotential studies. They are considered to be useful since they predict some important results which can be experimentally tested, some of which are here given.
GENE-FOR-GENE RELATIONSHIPS IN HOST: PARASITE SYSTEMS
Authors: Person Clayton
Published: August 2008

Theoretical consideration of the origin of gene-for-gene relationships led to the conclusion that such relationships, postulated by Flor for the Linum:Melampsora system, should occur as a general rule in host:parasite systems. An ideal gene-for-gene system, with five related host and parasite loci, was designed to illustrate the properties inherent in gene-for-gene systems, and to illustrate a new method of analyzing for these properties. Analyses of published data of the Solanum:Phytopthora and Linum:Melampsora systems proved that gene-for-gene relationships are in fact operative in these systems and that Flor's hypothesis—that for each specific locus in the host determining resistance and susceptibility there is a specific and related locus in the parasite which determines virulence and avirulence—is correct. Analysis of Flor's data showed, however, that most of his "single-gene" differential varieties actually possess two or more genes for resistance, and that resistance genes in these varieties need not fall into allelic or closely linked groups.
SEROLOGICAL AND PHYSICAL PROPERTIES OF SOME STONE-FRUIT VIRUSES: I. PREPARATIVE AND SEROLOGICAL TECHNIQUES
Authors: Willison R. S. , Weintraub M. , Tremaine J. H.
Published: August 2008

Strain Y.4 of the cherry yellows virus was purified from cucumber by four methods, which differed mainly at the clarification stage: A, the homogenate buffered at pH 6.5 was frozen; B, leaves were frozen and the expressed sap was buffered at pH 5.0; C, fresh expressed sap was diluted with pH 5.0 buffer; D, fresh expressed sap was dialyzed against.05 M acetate buffer at pH 4.5. One or two cycles of differential centrifugation were applied after clarification. Freezing usually inactivated the virus. Methods C and D yielded infective preparations. Ultraviolet absorption spectrum analysis, and particle size and sedimentation rate determinations, supported by infectivity tests, indicated that, in these infective preparations, the virus replaced most if not all of the components found in comparable extracts from healthy sources. The agar gel diffusion technique was used for precipitin tests. Virus antigen from cucumber sources reacted with homologous antiserum or with antiserum derived from infected cherry petals and vice versa.
TWIN OVULES IN PRUNUS AVIUM L.
Authors: Eaton George W.
Published: August 2008

Twin ovules, not previously reported for Prunus, occurred in from 5 to 12% of Windsor sweet cherry pistils. Rarely, twin seeds have been observed in mature fruits of other genera. The conclusions of earlier workers that twin seeds arise through fusion or fission of ovules or nucelli are not supported by the present study. Regardless of whether neither, one, or each ovule was a twin, two ovules were present in every fruit examined. Observations on the ovule development in Prunus avium indicate that twin ovules arise by the differentiation of separate nucelli in a single ovule primordium.
A RING CHROMOSOME IN ANF1HYBRID BETWEEN WHEAT AND AGROPYRON
Authors: Tsunewaki Koichiro
Published: August 2008

A plant having 41 normal rod-shaped chromosomes and a ring chromosome was found among hexaploid.F1hybrids from a wheat–Agropyron cross. Cytological investigations were carried out to determine the mitotic behavior of this ring chromosome.The investigations revealed that most of the possible products of the breakage–fusion–bridge cycle known to occur in a ring chromosome were present in root tip cells. The fact that a rod-shaped chromosome is not derived from a ring chromosome in the cycle was confirmed, because no metaphase cells examined had 42 or more rod-shaped chromosomes.About 80% of the ring chromosomes were eliminated from the root tips of the seedling after 26 days. The size of the ring chromosome did not appear to influence the rate of elimination. The polyploid nature of the plant may account for the rapid, non-differential elimination of this chromosome.
STUDIES ON THE VIRUS-STREAK SYNDROME IN TOMATOES
Authors: MacNeill Blair H. , Ismen Hikmet
Published: August 2008

The streak disease of tomatoes in Ontario has been shown to be double-virus in nature, resulting from the synergistic action of tobacco mosaic virus (TMV) and potato virus X (PVX). Expression of the disease was found to be a function of both virus components of the complex, a variation in strain characteristics of either TMV of PVX being reflected in the intensity of their interaction in the tomato.The extreme severity of streak in the greenhouse and field tomato crops in Ontario is associated with what appears to be a geographic strain of TMV. This virus, designated as PLV, is characterized by the induction of primary local lesion in petunia without subsequent systemic invasion of that host.Air temperature profoundly influences the development of streak, symptoms being masked above the critical temperature of 26 °C. This phenomenon is a true masking effect with both viruses becoming latent in the tomato host.
AN ANTIFUNGAL FACTOR FROM BARLEY OF POSSIBLE SIGNIFICANCE IN DISEASE RESISTANCE
Authors: Ludwig R. A. , Spencer E. Y. , Unwin C. H.
Published: August 2008

Susceptibility to Helminthosporium sativum in barley coleoptiles is associated with tissue senescence. Aqueous extracts of young coleoptiles show high antifungal activity. This activity disappears rapidly with age owing to the appearance of an inhibitor in the extracts. Preliminary characterization of the antifungal factor suggests an empirical formula of C9H17O7N. Inhibition of activity was found to be caused by various divalent cations. The results point to the particular importance of calcium.
DISTRIBUTION AND CYTOLOGY OF ELYMUS MACOUNII VASEY
Authors: Gross A. T. H.
Published: August 2008

The distribution of Elymus macounii Vasey in the Prairie Provinces of Canada is extensive and apparently governed by the occurrence of its putative parents, Agropyron trachycaulum (Link) Malte and Hordeum jubatum L. The hybrid E. macounii was produced by controlled cross-fertilization of A. trachycaulum and H. jubatum. Subsequently, octoploid E. macounii was obtained by colchicine treatment. Cytological studies indicated 2n = 28 for A. trachycaulum, H. jubatum, and E. macounii (both artificially produced and naturally occurring hybrids). Irregular meiosis of E. macounii and some irregularity in meiosis of octoploid E. macounii were observed.
THE PATHOGENICITY OF ISOLATES OF SEPTORIA AVENAE F. SP. AVENAE
Authors: Clark R. V. , Drayton F. L.
Published: August 2008

All isolates of Septoria avenae Frank f. sp. avenae studied were pathogenic on selected varieties of oats and there was no evidence of a differential reaction. The virulence of the isolates varied greatly and this variability was inherent in all groups of isolates. The dimensions, septations, and numbers of macrospores produced by the isolates on oat-leaf agar also varied greatly but there was no correlation between these variable characters and the disease rating of the isolates.
WHEY AS AN INHIBITOR OF STRIPE MOSAIC OF BARLEY
Authors: Hagborg W. A. F. , Chelack W. S.
Published: August 2008

The results of experimental applications of whole milk and whey to stripe mosaic virus inoculum or to barley plants prior to inoculation in the greenhouse established that contact transmission of stripe mosaic of barley was strongly inhibited by both milk and whey. Similarly, both skim milk and whey reduced the spread of field infection when applied as a spray. The low cost of whey suggests its possible economic utilization in the commercial control of virus diseases of plants.
DIFFERENTIAL RESPONSE OF CERTAIN BARLEY AND WHEAT VARIETIES TO HARDENING AND FREEZING DURING SPROUTING
Authors: Dantuma G. , Andrews J. E.
Published: August 2008

A number of barley and wheat varieties from different geographical areas were tested for cold hardiness in the sprouted seed stage. The young plants were subjected to a hardening process for varying periods and at different temperatures. Under appropriate conditions of hardening and freezing nearly all of the varieties of winter wheat and winter barley showed a similar hardening pattern, that is, a relatively high degree of hardiness and ability to harden in young stages of germination (up to 1 week of growth at 1.5 °C), a minimum hardiness at 2 or 3 weeks of hardening at 1.5 °C, and a second maximum of hardiness at about 6 weeks of hardening at 1.5 °C. Spring varieties and some West European winter wheats with low winter hardiness did not show the second maximum of hardiness after 6 weeks at 1.5 °C. In general, additional hardening for 1 week at −4 °C produced a striking increase in hardiness. For barley this increase was produced at all stages of development whereas for wheat there was a large increase only after 1 to 5 weeks of prehardening at 1.5 °C. Hardening at −4° C for longer than 1 week did not produce additional hardiness. Possibilities of testing for cold hardiness at different growth stages of sprouted seeds under various conditions of hardening are discussed.
THE DEVELOPMENT OF FOLIAR SYMPTOMS AND THE POSSIBLE CAUSE AND ORIGIN OF WHITE PINE NEEDLE BLIGHT
Authors: Linzon S. N.
Published: August 2008

Needle blight of eastern white pine (Pinus strobus L.) is characterized by an orange-red discoloration of the distal portions of current year needles. At Chalk River, Ontario, 600 seedlings and saplings of white pine were examined repeatedly throughout the 1957 and 1958 growing seasons for the appearance and development of needle blight symptoms. The first of these were faint pinkish spots on the stomata-bearing faces of needles in semimature (about four-week-old) tissue. These developed rapidly into orange-red bands which within a few days spread to the needle tips. Mature tissue was not susceptible to attack, so lesions which developed subsequently were always proximal, on younger tissues derived from basal meristems. Attacks which occurred in the early summer killed only limited areas at the tips of needles, whereas those that occurred when the needles were nearly full-grown involved most of their length. Needle blight incidence was confined to a few major outbreaks during one season and in each of these many trees developed typical symptoms at essentially the same time. Each of these major outbreaks of the disease occurred after 1 or more days of wet weather which was followed suddenly by a continuous sunny period. No microorganisms were isolated from tissues displaying the initial needle blight symptoms.The data with respect to the nature and occurrence of needle blight are believed to suggest that susceptibility to the unfavorable conditions which incite it is inherent in the individual and that differences in response among members of a local population depend on variations in susceptibility, rather than on a varying local predisposition among uniformly susceptible individuals. The blight is initiated in semimature leaf tissues only but then spreads distally throughout adjacent, more mature tissues with a similar pattern of breakdown.
CAMBIAL BEHAVIOR WITH REFERENCE TO CELL LENGTH AND RING WIDTH IN THUJA OCCIDENTALIS L.
Authors: Bannan M. W.
Published: August 2008

The relationship between ring width and length of wood cells was studied by reference to mature white cedar trees of various growth patterns. These included trees of similar diameter but diverse growth rates, trees with transition from wide to narrow rings or from narrow to wide rings in their peripheral growth, and trees with rings varying in width in different radii. Although much fluctuation occurred among individuals there was in general an inverse relationship between cell length and ring width. On the other hand, the variations in frequency of pseudotransverse divisions in the cambium, which might be expected to have a profound influence on cell length because of their involvement in cambial cell multiplication, were not obviously related to the growth rate. The frequency of pseudotransverse divisions in the fusiform initials apparently is geared neither to circumferential expansion nor to number of periclinal divisions in the cambium but rather seems to be related simply to linear radial increment.