bluuebunny/crossref_metadata_2025 huggingface dataset:
TAXONOMY, MORPHOLOGY, AND PATHOGENICITY OF RHIZOCTONIA SPECIES FROM FOREST NURSERIES
Authors: Saksena H. K. , Vaartaja O.
Published: August 2008

The history of the concept of the genus Rhizoctonia is reviewed. Ten species and one variety of Rhizoctonia were identified from the study of over 60 selected isolates obtained from the forest nurseries in Saskatchewan and Manitoba. These are R. dichotoma, R. endophytica, R. endophytica var. filicata, R. globularis, R. hiemalis, R. callae, R. lilacina, R. repens, R. rubiginosa, R. solani (Ceratobasidium filamentosum), and C. praticolum. The first five of these were previously described by the authors as new. This paper deals with the taxonomic descriptions of the remaining 6 species and the pathogenicity of all 10 species. Of the six species described here, R. callae, R. lilacina, R. repens, and R. rubiginosa are new records for Canada. C. praticolum is distinguished from R. solani in the imperfect stage on cultural and morphological characters. Comparative morphological studies show that chlamydospore characters were maintained consistently within a species, and their value as dependable diagnostic characters is emphasized.The pathogenicity of Rhizoctonia species was tested under aseptic conditions in test tubes and in partially sterile soil on tomato, lettuce, cabbage, beet, dill, caragana, cedar, elm, and pine seedlings. Mycelia of all the species invaded the tissues of all the host seedlings, showing no specialization. Ceratobasidium praticolum and R. dichotoma caused severe damping-off. C. praticolum appears to be by far the most widespread and virulent of all Rhizoctonia species in forest nurseries in Canada. R. solani, R. lilacina, and R. endophytica var. filicata, caused rotting of seeds, roots, and hypocotyls with varying intensity. R. callae, R. endophytica, R. globularis, and R. repens were characterized by production of chlamydospores inside the cortical cells of the roots, completely or partially filling them. This endophytic association affected the root development and general health of the seedlings adversely. Under certain conditions, the endophytes also attacked the aerial parts of the seedlings and caused some damping-off. R. hiemalis and R. rubiginosa were non-pathogenic, though their mycelia penetrated the root tissue.These studies indicate that the Rhizoctonia problem in forest nurseries is a complex one involving several species differing in their virulence and mode of attack.
STUDIES ON CLOVER YELLOW MOSAIC AND WHITE CLOVER MOSAIC VIRUSES
Authors: Pratt Michael J.
Published: August 2008

Two viruses, clover yellow mosaic (CYMV) and white clover mosaic (WCMV), were separated from mixed natural infections of various clovers by inoculation of differential hosts. The host reactions of four CYMV and two WCMV isolates were studied in detail. Precipitin tests showed that the two viruses are not related serologically. In cross-absorption tests different host reactions characterizing individual CYMV isolates were reflected in serological interactions; with WCMV isolates the relationship was less clearly defined. A comparison of isolates from different parts of the world by serological methods showed that CYMV is common in western North America, while WCMV occurs in Europe, North America, and New Zealand. Pea mottle and pea wilt viruses may be equated with CYMV and WCMV respectively.
ON THE NATURAL HYBRID POPULATION OF HEMEROCALLIS
Authors: Kawano Shoichi
Published: August 2008

A large natural hybrid population between Hemerocallis middendorffii and Hemerocallis yezoensis occurs at Otanoshike and its neighborhood in the eastern part of Hokkaido, Japan. This report is the result of a comparative study on external morphology and cytological analysis of the hybrid swarm at Otanoshike and of the parental species from various localities in Hokkaido. The hybrid population at Otanoshike represents morphologically an "introgressive status", and this fact is well understood in connection with the ecological condition of the habitat. Among the hybrid swarm intermediate types are dominant. Cytologically, all the material examined was diploid, i.e., it had 2n = 22.
PYRENOPHORA PHAEOCOMES (REB. EX FR.) FR.
Authors: Shoemaker R. A.
Published: August 2008

The history of Pyrenophora Fr. was reviewed with special reference to Pleospora Rab. It was concluded that the two genera are distinct. The following characteristics were found to be of diagnostic value for Pyrenophora: ascocarps very large, sclerotioid, slow-maturing, usually setose, occurring on grasses; ascospores large, nearly cylindrical with rounded ends, with 3–5–7 transverse septa, and a longitudinal septum in from one to all cells depending on species. In addition, the known conidial states of Pyrenophora were noted to be species of the hyphomycete genus Drechslera Ito.An authenticated specimen of P. phaeocomes from the Fries Herbarium was used as a neotype in the apparent absence of Rebentisch's specimen. Numerous ascospores were found among the immature ascocarps on the leaves, and taken as evidence that the fungus is an ascomycete. The conidial-state association was tenuously confirmed by the presence of one Drechslera conidium. It was concluded that the name Pyrenophora can be used for the genus of ascomycetes typified by P. phaeocomes.
THE GENUS ASCODESMIS
Authors: Obrist Walter
Published: August 2008

A study of the physiological, cytological, and morphological characteristics of four species of the genus Ascodesinis has been made. The genus represents a highly specialized coprophilous group of the operculate discomycetes, probably belonging to the Humariaceae. A new specific name (Ascodesmis sphaerospora nom. nov.) and a new species (Ascodesmis macrospora sp. nov.) are proposed.
CRITIQUE OF SOME VEGETATIONAL CONCEPTS AS APPLIED TO FORESTS OF NORTHWESTERN ALBERTA
Authors: Rowe J. S.
Published: August 2008

The application, by R. Plochmann, of certain European silvicultural and ecological concepts in the study and description of forests of northwestern Alberta is examined. His ideas of unidirectional succession to the single climax forest are criticized on the grounds that concepts such as succession and climax must always be related to specific terrain. Every forest community, and indeed every vegetational community, is the botanical part of a unique geographic ecosystem which gives it meaning, and it is neglect of the geographic framework which has led to the false assumptions that forest communities can be studied as things-in-themselves, and that vegetational concepts derived in one region can be transplanted unchanged to others.
EVOLUTION OF CARBON DIOXIDE BY TOBACCO LEAVES DURING THE DARK PERIOD FOLLOWING ILLUMINATION WITH LIGHT OF DIFFERENT INTENSITIES
Authors: Tregunna E. B. , Krotkov G. , Nelson C. D.
Published: August 2008

Detached tobacco leaves were placed in a closed-circuit apparatus and the air was continuously circulated over the leaves and through an infrared CO2 analyzer. From the known volume of the apparatus and the percentage of carbon dioxide in its air, the amounts of carbon dioxide either absorbed or evolved by a leaf were calculated.When, after a period of illumination, leaves were darkened, the attainment of their steady rates of respiration was preceded by two outbursts of carbon dioxide evolution. Since these outbursts occurred only after a period of illumination, it has been concluded that both were the result of photostimulation. The peak of the first outburst was usually considerably higher than that of the second. It was of short duration and the height of its peak was accentuated by the increased light intensity in the preceding light period. The second outburst lasted longer and prior light intensity had no effect on the height of its peak.
THE GENUS THERRYA
Authors: Reid James , Cain R. F.
Published: August 2008

The genus Therrya Sacc. & Penz. is shown to include two distinct species, Therrya pini (Alb. & Schw.) von Höhn. and Therrya fuckelii (Rehm) Kujala, which have been considered synonymous. The name Coccomyces strobi is proposed for the organism occurring on Pinus strobus in North America which has been considered synonymous with Therrya pini or referred to under invalid or unpublished binomials.
STUDIES ON THE CYTOCHROME OXIDASE AND OXIDATION PATHWAY IN UREDOSPORES OF WHEAT STEM RUST
Authors: White G. A. , Ledingham G. A.
Published: August 2008

Electron transport to oxygen in a particulate fraction from uredospores of Puccinia graminis var. tritici occurs through a series of carriers similar to those of other fungi and higher plants.Experiments with various enzyme inhibitors and measurements of the oxygen affinity of respiration have shown that cytochrome oxidase mediates the final step in the sequence of electron transfer. The enzyme was localized in a fraction sedimenting at 20,000 g and was typically inhibited by cyanide, azide, and CO-dark, the latter inhibition being light-reversible. Other enzymes present were succinic-cytochrome c reductase, DPNH- and TPNH-cytochrome c reductase, dye reductase, malic dehydrogenase, isocitric dehydrogenase, and glycerol-1-phosphate dehydrogenase. Particulates failed to oxidize DPNH unless an electron acceptor was added. An increase in the activity of several of the respiratory enzymes was noted upon spore germination.Succinic-cytochrome c reductase was only partially sensitive to Antimycin A, HOQNO, and the naphthoquinone, SN 5949. These compounds markedly inhibited a labile portion of the DPNH-cytochrome c reductase activity but had little effect on the stable activity remaining in aged particles. Menadione, but not vitamin K1, stimulated electron transfer. Antimycin A and SN 5949 virtually blocked spore respiration suggesting a "Slater-type" factor in the intact pathway of oxidation.
CULTURAL STUDIES OF BOLETACEAE: GYRODON MERULIOIDES AND FOUR SPECIES OF BOLETINUS
Authors: Pantidou Maria E.
Published: August 2008

Methods and techniques for culturing and studying species of Boletaceae in culture are described. Some preliminary views as to the possibilities and limitations of the taxonomic criteria, to be used for identifying species in culture, are discussed. Descriptions and illustrations of Gyrodon merulioides (Schw.) Sing., Boletinus cavipes (Opat.) Kalchbr., Boletinus pictus (Peck) Peck, Boletinus spectabilis (Peck) Murrill, and Boletinus grisellus Peck, which have not been previously described in culture, are presented.
A NEW SPECIES OF AGROPYRON FROM THE GREAT LAKES
Authors: Gillett J. M. , Senn H. A.
Published: August 2008

The Agropyron population from the shores of the upper Great Lakes is considered to be morphologically distinct from that of the plains' species A. dasystachyum (Hook.) Scribn. and is here described as A. psammophilum. The geographical range is mapped and shown to be disjunct from that of the plains' species. A. psammophilum consistently occupies a sandy shore habitat. The species is tetraploid (2n = 28). Several explanations for the presence of empty pollen grains in some specimens of A. psammophilum are presented.
MODIFIED INCOMPATIBILITY OF BUCKWHEAT FOLLOWING IRRADIATION
Authors: Sharma K. D. , Boyes J. W.
Published: August 2008

Among plants grown from buckwheat "seeds" which had been exposed to X rays or thermal neutrons two thrum-flowered plants each had a branch bearing modified flowers. One thrum plant had a branch bearing homostyled flowers and the other a branch bearing pin flowers. A thrum plant in the progeny of the latter plant was self-fertile, produced no progeny in crosses with other thrum plants, but was fertile in crosses with pin-flowered plants. These cases are discussed in relation to a postulated S supergene controlling incompatibility in buckwheat.
A CYTOLOGICAL STUDY OF ASCOCYBE
Authors: Wilson Charles M.
Published: August 2008

The nuclear behavior in the life cycle of Ascocybe grovesii is described. The chromosome number is given as six from counts made of chromosomes in the meiotic divisions in the asci. The ascophores are described as diploid, and as a consequence there is no fusion of nuclei in the asci.
THE GENUS MICROASCUS
Authors: Barron G. L. , Cain R. F. , Gilman J. C.
Published: August 2008

Descriptions are given of 14 species of Microascus. M. pyramidus Barron and Gilman is described as a new species and M. trigonosporus var. macrosporus Orr as a new variety. The conidial stage and cultural characteristics are described for most of the species. The genus Microascus is separated from Petriella on the basis of the smaller, lighter-colored ascospores as well as the type of conidia. Most of the species have a Scopulariopsis-type of conidial stage. M. variabilis Massee and Salmon is placed in synonomy under M. longirostris Zukal. Microascus stysanophorus (Matt.) comb. nov. is proposed.
COCHLIOBOLUS SATIVUS: IV. DRUG-RESISTANT, COLOR, AND NUTRITIONALLY EXACTING MUTANTS
Authors: Tinline R. D.
Published: August 2008

Auxotrophic mutants of Cochliobolus sativus were obtained from survivors of ultraviolet radiation by a modified total-isolation technique. Five or six hyphal tip isolations made from each survivor were tested for nutritional deficiencies. Although 0.48% of the survivors yielded auxotrophs, only about one-third of the hyphal tip isolations from these survivors were auxotrophic. Apparently, mutation in a multinucleate propagule resulted in a heterokaryotic culture and only some of the isolations from a culture were homokaryotic for the mutation. Some of the mutants were morphologically distinct from their parent and one, a methionineless strain, had white spores. Results indicated that recurrent requirements for growth occurred at different mutational sites.A strain resistant to the antibiotic anisomycin appeared as a spontaneous mutation. This strain grew at 1500 and its spores germinated at 1750 p.p.m.; wild-type isolates grew only at 75 and their spores germinated at 100 p.p.m. of the drug. The resistant mutant was pathogenic to wheat seedlings.
REMOVAL OF HOST ANTIGENS FROM PLANT VIRUS PREPARATIONS BY ION EXCHANGE CHROMATOGRAPHY
Authors: Tremaine J. H.
Published: August 2008

The separation of a carnation virus from smaller cowpea-host antigens was achieved by column chromatography on a strongly basic ion-exchange resin. The separation was demonstrated by infectivity and serological tests, analytical ultracentrifugation, and ultraviolet spectrophotometry. The method is proposed for the removal of similar host components from preparations of other spherical plant viruses.
TERMINOLOGY OF PLANT VIRUS DISEASES
Authors: Welsh Maurice F.
Published: August 2008

not available
EXPERIMENTS ON THE MECHANISM OF INDUCED DORMANCY IN WILD OATS, AVENA FATUA L.
Authors: Hay J. R.
Published: August 2008

Experiments were conducted on the factors involved in the induction of dormancy in wild oats. It was shown that when the supply of air reaching the embryo of imbibed seeds is restricted, changes occur in the caryopses so that when the seeds are subsequently dehulled and the caryopses exposed to air they are unable to germinate. Induction of dormancy is greater at 25 °C than at 7 °C. The site of the mechanism controlling induced dormancy is in the embryo or endosperm rather than in the seed coat or hulls. If dormant caryopses are punctured they germinate even when the wound is covered with lanolin or agar. Inhibitors were found in methanol extracts of both dormant and non-dormant caryopses, but it was concluded that they are not responsible for induced dormancy. An inhibitor which leaches from the hulls of wild oats completely stops growth of excised embryos but dormancy can be induced in the absence of hulls. Dormant caryopses absorb 2,3,6-triphenyl-tetrazolium chloride but are unable to reduce this dye. The mechanism of induced dormancy is discussed.
SOME EFFECTS OF RADIATION ON BUCKWHEAT
Authors: Sharma K. D. , Boyes J. W.
Published: August 2008

Some samples of buckwheat "seeds" were treated with X-rays at doses ranging from 5 to 40 thousand roentgens, and other samples with thermal neutrons for times ranging from 4 to 33.5 hours and at doses ranging from 0.61 × 1013 to 5.87 × 1013 thermal neutrons per cm2. Lower doses of both X-rays and thermal neutrons stimulated earliness of development (sprouting, expansion of first true leaf, and flowering) and height. Higher doses produced a retarding effect on these characters. The seed set on selling was reduced in the treated material, with thermal neutrons having a more drastic effect than X-rays. Progenies of the treated plants surpassed the controls in earliness, height, and the average maximum number of leaves per plant and were significantly more self-fertile. It is suggested that increased heterozygosity and radiation-induced constructive mutations of polygenes may both contribute to the improvement of earliness, plant height, and self-fertility in buckwheat treated by irradiation.
STACHYBOTRYS AURANTIA SP. NOV. FROM SOIL
Authors: Barron G. L.
Published: August 2008

Stachybotrys aurantia is described as a new species of hyphomycete isolated from soil; it differs from other described species of the genus in phialide and phialospore morphology and is also distinctive in having pale orange or salmon-colored phialospores. Cultural studies show that it has a rapid growth rate and, on a minimal synthetic medium, requires a biotin supplement for normal growth.
CYTOTAXONOMIC STUDIES IN THE TRIBE CYNAREAE (COMPOSITAE)
Authors: Moore R. J. , Frankton C.
Published: August 2008

Chromosome numbers of 40 taxa of nine genera of the Cynareae together with discussions of pertinent taxonomic problems are presented. Chromosome counts for 26 taxa are presented for the first time; the chief of these are: Carduus cernuus, n = 11; C. pycnocephalus and C. tenuiflorus, 2n = 54; Cirsium arachnoideum, C. obvallatum, C. pendulum, C. tricholoma, 2n = 34; Echinops (six species), 2n = 30; Notobasis syriaca, 2n = 34; Onopordum (two species), 2n = 34; Saussurea densa, 2n = 26; Silybum eburneum, n = 17. The morphology of the chromosome complements is discussed in relation to the interrelationships and phylogeny of these genera. Cytological evidence supports the retention of Notobasis and Chamaepeuce as distinct from Cirsium.
DURANDIELLA PSEUDOTSUGAE N. SP.; TAXONOMY, CULTURAL CHARACTERISTICS, LIFE HISTORY, AND HOST RESPONSE
Authors: Funk A.
Published: August 2008

The perfect state of Chondropodium pseudotsugae White is shown to be a new species of Durandiella, for which the name D. pseudotsugae is proposed. Maximum growth in culture is obtained on corn meal agar at 15 °C. Apothecia are produced in the spring; the ascospores are forcibly discharged; pycnidia persist throughout the summer and discharge spores only when moistened. The host response of Douglas fir is the production of a "button" of persistent secondary periderm beneath the infected area.
THE MORPHOLOGY AND GENETICS OF WILD-TYPE AND SEVEN MORPHOLOGICAL MUTANT STRAINS OF NEUROSPORA CRASSA
Authors: Srb Adrian M. , Murray Jay C.
Published: August 2008

Comparisons of morphological mutant strains of Neurospora crassa with the wild type and with each other reveal differences in: (a) the general form of the colonies, resulting from different relative growth rates of the aerial submerged and surface mycelia; (b) the frequency of hyphal branching; (c) the abundance of conidia; (d) the compactness of the mycelia; and (e) various characteristics of the hyphae. The typical variant properties of each mutant strain depend upon the activity of some single mutant gene. The linkage position of six of the mutant genes is reported.
ALTERATION OF LEAF SIZE AND STRUCTURE IN CONVALLARIA MAJALIS CAUSED BY EXTREME SHADE
Authors: Cormack R. G. H.
Published: August 2008

This paper presents a comparative anatomical study of normal shade and extreme shade leaves of a common garden plant (Convallaria majalis L.). Striking differences in leaf form, shape, size, thickness, and internal structure were observed. The failure of the mesophyll cells to enlarge is thought to account for the marked thinness and peculiarly folded condition of extreme shade leaves.
PRODUCTION OF PERITHECIA OF VENTURIA INAEQUALIS (CKE.) WINT. ON STERILE APPLE LEAF DISCS
Authors: Ross R. G. , Hamlin S. A.
Published: August 2008

Perithecia of Venturia inaequalis were produced in vitro on apple leaf discs which had been sterilized in propylene oxide and then placed on water agar, potato-dextrose agar, or potato-dextrose agar supplemented with apple leaf decoction. The discs were inoculated with a drop of a conidial suspension of two sexually compatible strains of V. inaequalis, incubated at room temperature for 2 weeks, and then grown at 8 °C for 4 to 5 months.Perithecia were also produced on sterile leaf discs placed on perlite, vermiculite, sand, filter paper, or glass rings in screw-cap vials with distilled water added to supply moisture. Using perlite, perithecia were developed on discs of green and fallen apple leaves collected from the orchard at intervals during the summer and fall and on leaves at different stages of development from trees growing in the greenhouse. Few perithecia developed on newly unfolded leaves from the latter unless the leaves were leached before inoculation. Perithecia developed on sterile discs from green apple leaves of varieties with varying degrees of susceptibility to V. inaequalis and on green leaf discs of the pear variety Kieffer. Perithecia production was most abundant at 4 °C and no perithecia were produced at or above 15 °C.
THE NATURE OF PHOTOSYNTHATE IN PINUS STROBUS SEEDLINGS
Authors: Shiroya T. , Krotkov G. , Nelson C. D. , Slankis V.
Published: August 2008

Representatives of C14-labelled sugars, amino acids, and organic acids were placed on several different kinds of exchange resins and their absorption and elution from such resins was determined. From the data obtained, a combination of IR 120 in the H+ form and IRA 400 in the formate form was selected for the initial separation of pine extracts into their sugar, amino acid, and organic acid fractions. These fractions were resolved further by two-dimensional paper chromatography.Two-year-old Pinus strobus seedlings were illuminated in C14O2 for 8 hours either at 2500 or 250 ft-c. Then their shoots were extracted with 80% ethanol and the distribution of C14 in various components of the photosynthate was determined, as described above.The results obtained were essentially the same for seedlings illuminated either with 2500 or 250 ft-c. Not more than 10% of the absorbed C14 were found in the ethanol-insoluble residue. About 98% of the ethanol-soluble C14 were found in the sugar fraction, with the remaining 2% being about equally divided between the amino and organic acids. Sucrose formed about 75% of the sugar fraction, with glucose and fructose making up additional 20%. Only small amounts of raffinose were found.
VALSA MYINDA COOKE AND ELLIS AND CRYPTODIAPORTHE MYINDA SENSU WEHMEYER, TWO DISTINCT SPECIES ON ACER
Authors: Reid James , Cain R. F.
Published: August 2008

Valsa myinda Cooke and Ellis is correctly placed in the genus Valsa. The specimens described under the name Cryptodiaporthe myinda (Cooke and Ellis) Wehmeyer belong to a different species that is properly placed in the genus Cryptodiaporthe and for which there is no valid species name available. Cryptodiaporthe acerinum sp. nov. is therefore proposed for this fungus, with collections available from New York, New Jersey, West Virginia, and Ontario. All of the collections of these two species are on Acer.
A NEW FIXATIVE AND IMPROVED PROPIONOCARMINE SQUASH TECHNIQUE FOR STAINING FUNGUS NUCLEI
Authors: Lu Benjamin C.
Published: August 2008

A new fixative, which is composed of butyl alcohol, acetic acid, and chromic acid, is introduced. This BAC mixture fixes nuclear details, and cytoplasm is not granulated to any extent. Details of staining procedures and helpful hints for successful staining are given. This improved technique differentiates all stages of nuclear division from interphase to interphase in the vegetative hyphae of fungi as well as in the sexual stage. Chromosomes, nucleoli, and centrioles are clearly shown. A series of mitotic figures in germ tubes of Neurospora crassa and some meiotic figures in Gelasinospora calospora are attached as illustrations.
A NEW SPECIES OF CHAETOMIUM FROM INDIAN SOILS
Authors: Rai J. N. , Mukerji K. G.
Published: August 2008

A new species Chaetomium fusisporale Rai & Mukerji, isolated from usar soils of Lucknow (India), is described. It has straight hairs and fusiform ascospores with a single germ pore.
OBSERVATIONS ON THE ORIGIN AND MULTIPLICATION OF PLASTIDS
Authors: Badenhuizen N. P.
Published: August 2008

Plastids were investigated in ultrathin sections of young developing tissues of corn endosperms, pea cotyledons, and potato. The electron photographs give support to the possibility that plastids are produced de novo, as well as by division. Some of the pictures suggest that, under certain conditions, plastids may also multiply by a process of delimitation brought about by invaginations of the plastid membrane.Several aspects of plastids and mitochondria can be directly compared, but the latter are much more limited in their response to environmental changes. An origin de novo for plastids is in agreement with known genetical behavior and results of recent biochemical investigations.
CROSS PROTECTION AND INTERFERENCE WITH SOME STONE-FRUIT VIRUSES
Authors: Willison R. S.
Published: August 2008

One-year-old virus-free sour cherry trees of the variety Montmorency were inoculated singly with buds from different source trees infected with sour cherry yellows, necrotic ring spot, prune dwarf, and tatter leaf respectively. The infections thus established in the test trees were later challenged by inoculation with isolates from different sources. Conspicuous recurrent symptoms occurred when infection from a tatter leaf isolate was challenged by either of two necrotic ring spot virus strains, but not when the order of challenge was reversed. These symptoms are interpreted as a synergistic response to infection by two viruses, one from each source, within a limited range of interaction. Trees previously infected with necrotic ring spot when reinoculated with cherry yellows isolates showed symptoms of cherry yellows, usually preceded by secondary shock. The reciprocal challenges, on the other hand, induced no symptoms of necrotic ring spot, probably because each of the cherry yellows sources carried a strain of the necrotic ring spot virus. There were indications, however, of interference between the two viruses. Infection with the prune dwarf virus did not protect against subsequent infection with the cherry yellows virus. Mixed infections with the necrotic ring spot and prune dwarf viruses did not cause cherry yellows.
CYTOTAXONOMY AND CANADIAN DISTRIBUTION OF CIRSIUM EDULE AND CIRSIUM BREVISTYLUM
Authors: Moore R. J. , Frankton C.
Published: August 2008

The morphology and Canadian distributions of Cirsium edule Nutt. and C. brevistylum Cronq. are described. Both species have the chromosome number 2n = 34. The probable evolution of the species is discussed. A natural hybrid between these species has been found on Vancouver Island and is named C. × vancouverense Moore & Frankton.
MECHANISM OF ACTION OF GIBBERELLIC ACID: INHIBITION OF α-AMYLASE DEVELOPMENT DURING GERMINATION OF BARLEY BY CHLORAMPHENICOL AND ITS REVERSAL BY GIBBERELLIC ACID
Authors: Srivastava B. I. Sahai , Meredith W. O. S.
Published: August 2008

Barley kernels germinated in water, in solutions of gibberellic acid (GA), in chloramphenicol sodium succinate (CAL), and in combinations of GA and CAL, for 5 days were analyzed daily to determine growth and α- and β-amylase, proteinase, and respiratory activities. Respiration, growth, and amylase activities were inhibited by CAL, but were accelerated by GA. Combined treatment of CAL and GA partially reversed the inhibitive effects of CAL on respiration and growth, but amylase development approached that of GA-treated seeds. No correlations were found between proteinase activity and respiration or α-or β-amylase activities. The significance of these findings with respect to α-amylase formation and mode of action of GA is discussed. It is suggested that α-amylase is synthesized during germination and that GA accelerates this synthesis.
AGROPYRON MOSAIC AS A DISEASE OF WHEAT IN CANADA
Authors: Slykhuis John T.
Published: August 2008

Agropyron mosaic virus (AMV) is common on Agropyron repens (L.) Beauv. in southern Ontario and Quebec and has been found on Prince Edward Island and in southeastern Saskatchewan. It was also found on a few winter wheat plants in many fields in southern Ontario each year since 1957, and on spring wheat in Saskatchewan in 1961. AMV has not appeared to be economically important, but the occasional high incidence of infection in wheat near diseased A. repens and the fact that infected plants were sometimes severely stunted have indicated that it could be important under favorable conditions.Wheat was more susceptible than A. repens, or any of the other hosts tested. Usually all wheat plants became infected when inoculated with sap of diseased plants diluted 1:64, and 50% became infected with dilutions of 1:256. Symptoms appeared in 6 days at temperatures of 20° and 25 °C, but were most pronounced at 15 °C. No symptoms developed on wheat kept at 10° or 35 °C for 19 days after inoculation, but sap from these plants was infectious.All isolates of AMV obtained from A. repens and most from naturally diseased wheat caused only mild symptoms on wheat, but some isolates from wheat caused severe chlorosis and stunting. In field tests, manual inoculation with severe isolates reduced yields of spring wheat 25% to 75%, and of winter wheat up to 42%. Up to 100% of the winter wheat plants in small plots sown near naturally diseased wheat during June to late August became infected, illustrating that AMV can be perpetuated on immature wheat. Less infection developed in plots sown in September or later.Eriophyid mites, including Aceria tulipae (K.), Abacarus hystrix (Nal.), and Vasates mckenziei K. were present on naturally diseased plants, but none of these mites has been proved a vector of AMV.
CULTURE AND TAXONOMY OF CYATHUS EARLEI
Authors: Brodie Harold J.
Published: August 2008

Cyathus earlei Lloyd is a Bird's Nest Fungus previously known chiefly from the American tropics. A more recent collection from Mexico is described and compared with older herbarium material. The Mexican collection yielded viable spores and this made possible a study of the fungus in culture. It shows marked similarity to C. olla Pers. in the mode of spore germination and the appearance of mycelium. Attempts to obtain hyphal fusions between mycelia of C. earlei and C. olla were unsuccessful; C. earlei is believed to be a distinct species although closely related to C. olla.
THE PARASEXUAL CYCLE AND LINKAGE RELATIONSHIPS IN THE STORAGE ROT FUNGUS PENICILLIUM EXPANSUM
Authors: Barron G. L.
Published: August 2008

One hundred and four nutritional, morphological, and acriflavine-resistant mutants were produced in a strain of Penicillium expansum isolated from an infected apple. Nutritional mutants were induced more readily with ultraviolet than with gamma radiation. Heterocaryons were established between strains involving up to eight pairs of markers. Heterozygous diploids were recovered with comparative ease following treatment of the heterocaryons with D-camphor but with great difficulty in untreated heterocaryons. Screening of more than 500 million conidia from three untreated heterocaryons failed to yield a diploid. Analysis of 110 independent segregants from the heterozygous diploid M53/M67 has resolved seven genes into two linkage groups, viz. I: w3bi1pyr1br3, and II: nic2ri1acr1.
CLOVER PHYLLODY AND STRAWBERRY GREEN PETAL DISEASES, CAUSED BY THE SAME VIRUS IN EASTERN CANADA
Authors: Chiykowski L. N.
Published: August 2008

Experiments were conducted to determine the relationship between clover phyllody and strawberry green petal diseases in Eastern Canada. Clover phyllody virus from naturally infected ladino clover (Trifolium repens L.) in Quebec was transmitted by Aphrodes bicinctus (Schrank) to strawberry (var. Redcoat and Sparkle) and ladino clover. Symptoms on infected strawberry were typical of green petal. Strawberry plants, naturally infected with green petal, were obtained from Kentville, N.S., La Pocatière, Que., and Charlottetown, P.E.I. The virus was transmitted to ladino clover, red clover (Trifolium pratense L.), and strawberry (vars. Redcoat, Guardsman, Senator Dunlap, and Grenadier) by A. bicinctus and to ladino clover and aster (Callistephus chinensis Nees) by Macrosteles fascifrons (Stal).On the basis of leafhopper transmission and symptomatology, it is concluded that clover phyllody and strawberry green petal diseases in Eastern Canada are caused by the same virus.
Energy-momentum distribution in General Relativity and teleparallel theory of gravitation
Authors: Sharif M , Nazir K
Published: August 2008

This paper investigates the energy-momentum distribution in General Relativity and the teleparallel theory of gravitation. We use Einstein, Landau–Lifshitz, Bergmann–Thomson, and Moller’s prescriptions in both the theories to evaluate the energy-momentum distribution of the Hiscock–Gott metric (inside and outside the stringlike object). It is shown that for outside the stringlike object, these energy-momentum complexes give a constant energy distribution in both theories. However, these turn out to be different inside the stringlike object. It is worth mentioning that both the theories give constant energy-momentum in all the prescriptions except for Moller’s inside and outside the stringlike object at large distances.PACS Nos.: 04.20.-q, 04.20.Cv
Fundamental aspects of the vortex flow on cones. Angular characterization of hyperlifting vortex torques; the law of filiation
Authors: Abene A , Dubois V
Published: August 2008

This paper describes in detail the fundamental aspects of the vortex flow developed on the upper surface of a cone having an apex angle of 68.6°. It is one of a large number of studies carried out in the wind tunnel of the Valenciennes University aerodynamics and hydrodynamics laboratory whereby visualizations have enabled the flow of vortex structures to be monitored and consequently their development and positioning, under the influence of apex angles and at increasing angles of incidence, to be determined and defined. The existence and the preferential nature of intervortex angles are here confirmed and it has been found, by analogy with studies carried out on other types of slender bodies, that the law of filiation is applicable to the angular characterization of hyperlifting vortex torques and to the angular correspondence existing between their main and secondary structures. These findings suggest that there is a certain universality in the behaviour of these properties although no current theory would seem to be able as yet to provide a straightforward explanation of the phenomena.PACS Nos.: 44, 47
Calculation of ionized impurity-scattering probability with scattering angles in GaN
Authors: Mallick P S , Kundu J , Sarkar C K
Published: August 2008

The probability of scattering by ionized impurities has been calculated as function of the scattering angle for various energy values of the electrons in gallium nitride at 77 K. It is found that for electron energies higher than 0.1 eV, almost-zero angle scatterings are most prevalent.PACS Nos.: 72.10.–d, 72.20.Fr
On first-order generalized Maxwell equations
Authors: Kruglov S I
Published: August 2008

The generalized Maxwell equations including an additional scalar field are considered in the first-order formalism. The gauge invariance of the Lagrangian and the equations is broken resulting in the appearance of a scalar field. We find the canonical and symmetrical Belinfante energy-momentum tensors. It is shown that the traces of the energy-momentum tensors are not equal to zero and the dilatation symmetry is broken in the theory considered. The matrix Hamiltonian form of equations is obtained after the exclusion of the nondynamical components. The canonical quantization is performed and the propagator of the fields is found in the first-order formalism.PACS Nos.: 03.65.Pm, 03.70.+k, 04.20.Fy
Nesting and parental care in the mud turtle, Kinosternon flavescens
Authors: Iverson John B.
Published: August 2008

Female yellow mud turtles (Kinosternon flavescens) in the Nebraska Sandhills nest while completely buried underground, and remain with their single annual clutch of eggs for 1 to more than 38 days. The annual incidence of nest attendance seems to be inversely correlated with rainfall between mid-May and mid-June. Egg mortality may be reduced by the effects of the female's presence on both predation on the eggs and soil moisture at the nest.
On the effectiveness of artificial shelters in the study of population attributes of small terrestrial gastropods
Authors: Boag D. A.
Published: August 2008

The relative effectiveness of artificial shelters in quantifying population attritubes of species of small terrestrial snails was evaluated. The proportions of replicated, artificial populations found adhering to the lower surfaces of such shelters (squares of masonite), from May through July, averaged 20% for Discus cronkhitei and 33% for Euconulus fulvus. Variation between inspections in the numbers of both species recorded adhering to the shelters was influenced by both temperature (fewer snails were recorded when mean temperatures for the preceding 24 h were < 7.5 °C and > 17.5 °C), and precipitation (fewer snails were recorded when > 2 mm of precipitation were recorded in the previous 48 h than when < 2 mm fell). The numbers of individuals of each species on each plot declined annually over the 3-month period, from an initial density of 50 to a final average density of 5 individuals/m2. This loss was related to mortality in situ (ca. 12% in each species over 1987 and 1988), the remainder disappearing from the plots probably as the result of dispersal during periods of heavy precipitation. The implications of this recorded loss for population regulation in these species are discussed.
Nestmate and nest discrimination among workers from neighboring colonies of social wasps Polistes exclamans
Authors: Pfennig David W.
Published: August 2008

I examined nestmate and nest recognition among worker paper wasps Polistes exclamans on neighboring colonies in a dense nesting aggregation. In the laboratory, there was a significant positive correlation between the difference in preference toward nestmates and non-nestmates and internest distance (i.e., distance in the field between the nestmates' and non-nestmates' nests). This is the first demonstration of a distance effect in nestmate recognition ability among Polistes. The field significance of the laboratory bioassay of nestmate preference was confirmed by releasing in the field workers whose nests had been removed (i.e., orphaned workers) and finding that they joined colonies near the site of their original nest. Orphaned workers also tended to join smaller colonies, perhaps because these workers had a greater opportunity for reproduction on smaller colonies. This pattern may also reflect a greater tendency on the part of inhabitants of smaller nests to admit joiners, because the addition of a worker may have had a greater impact on colony success on a smaller colony than on a larger nest. Finally, workers prefer fragments of nests located closer in the field to the workers' colony than fragments of more distant nests. This ability may aid workers in choosing which nests to join and which to rob.
Impact of deltamethrin insecticide on Chironomidae (Diptera) of prairie ponds
Authors: Morrill P. K. , Neal B. R.
Published: August 2008

Deltamethrin insecticide was applied by air, at recommended field application rates (7.5 g/ha), to two prairie ponds in June, 1986. Larval and emerging Chironomidae densities were monitored in the treated ponds and in two untreated ponds for 1 month prior to spraying, the remainder of the summer after spraying, and in the late part of the following spring. Following deltamethrin application, the density of chironomid larvae declined by two orders of magnitude in the treated ponds relative to the untreated ponds, with all genera being affected. Chironomid emergence declined in both the treated and untreated ponds. The pattern of recovery of the chironomid community was followed by multivariate analysis of larval genera abundances and qualitative comparisons of emerging species. The two treated ponds recovered at different rates: the community in one pond appeared to have recovered by 2 months after treatment, whereas that of the other treated pond showed little recovery until 1 year following treatment. In view of the high natural variation of chironomid communities and their habitats on the prairies, basic knowledge about these temporary pond ecosystems must be gathered in order to understand the long-term impact on such habitats of using deltamethrin and other insecticides.
Intraspecific variation in body size, metabolic rate, and reproduction of deer mice (Peromyscus maniculatus)
Authors: Earle Michael , Lavigne D. M.
Published: August 2008

Deer mice (Peromyscus maniculatus) from three populations were used to examine patterns of covariation among body size, metabolic rate, and selected reproductive and developmental traits. Mass at birth and at 21 days, growth rates of individual neonates and whole litters, litter size, interlitter interval, and metabolic rates of adult females were used as dependent variables against maternal mass in allometric equations. Litter mass was positively correlated with maternal mass within each of the three populations. Conversely, litter size, litter mass at 21 days, litter growth rate, interlitter interval, and maternal metabolic rate were correlated with maternal mass in only one or two of the populations. Neonatal traits (mean mass of individuals at birth and at weaning and their growth rates) were consistently independent of maternal mass. There was no significant relationship between any of the reproductive parameters measured and metabolic rate of individual females. These results support the view that patterns of covariation in life history traits, metabolic rate, and maternal mass, which are generally evident in interspecific comparisons, are not necessarily apparent at the level of individuals within a single population.
Potential for social interaction in a natural population of prairie voles (Microtus ochrogaster)
Authors: McGuire Betty , Pizzuto Theresa , Getz Lowell L.
Published: August 2008

Many hypotheses on the role of social behavior in population regulation of microtine rodents assume that social interactions are more frequent at high density than at low density. We evaluated this assumption by measuring potential for social contact in a population of prairie voles (Microtus ochrogaster). Our livetrapping regime monitored presence of resident and nonresident animals at the periphery of home ranges of social groups. Resident adults and young of both sexes were captured at home range boundaries. Potential for social interaction with nonresidents was greater at the periphery of home ranges than at nests. Intruders tended to be male adults from neighboring social groups. Presence of adult males in the resident group played an important role in deterring visits by nonresident males. During the spring, summer, and autumn reproductive period, number of captures of nonresident males, but not females, showed a strong positive relationship with population density. Despite relatively high densities during the winter nonreproductive period, there were few captures of residents and nonresidents at the periphery of home ranges. We conclude that the relationship between potential for social interaction and population density varied as a function of sex and season.
Seasonal occurrence of the leopard seal, Hydrurga leptonyx, in the Kerguelen Islands
Authors: Borsa Philippe
Published: August 2008

Five consecutive years of observations (1982–1986), mainly along the eastern coast of Kerguelen Island, indicate a seasonal presence of juvenile leopard seals, with a peak in September and October. Smaller numbers of adults are present throughout the year. The occurrence of leopard seals may be related to the presence and period of reproduction of different penguin species (king, gentoo, rockhopper, and macaroni penguins), which are part of the seal diet.
Energy requirements for maintenance and growth of captive harbour seals, Phoca vitulina
Authors: Markussen Nina Hedlund , Ryg Morten , Øritsland Nils Are
Published: August 2008

Four captive harbour seals were fed with herring both at restricted and at ad libitum levels during 1985 to 1988. The maintenance requirement, calculated from the x-intercept of the regression, was 194 ± 71 kcal∙kg body weight−0.75∙day−1. Assuming that metabolizable energy is 82.8% of gross energy, the maintenance requirement is 161 kcal∙kg body weight−0.75∙day−1. There was no significant difference in maintenance requirement between individuals or between age classes, and neither was there any significant difference between seasons. The gross energy requirement of growth was 909 kcal/100 g.
Diel pattern of emergence in grayling (Thymallus thymallus Linnaeus, 1758)
Authors: Bardonnet Agnès , Gaudin Philippe
Published: August 2008

The emergence rhythm of grayling fry (Thymallus thymallus) was studied under semi-natural rearing conditions, using special traps buried in the gravel. The diel pattern of emergence proved to be mainly diurnal, with a maximum just after sunrise. The discussion emphasizes the fact that this distinguishes the grayling from other salmonids, and since eggs are buried at a reduced depth, proposes the hypothesis that light conditions during development influence the daily pattern of emergence.
Phylogenetic analysis of Megalobatrachonema Yamaguti, 1941 (Ascaridida: Cosmocercoidea: Kathlaniidae): reinstatement of Chabaudgolvania Freitas, 1958
Authors: Richardson Jane P. M. , Adamson Martin L.
Published: August 2008

The genus Megalobatrachonema (family Kathlaniidae; order Ascaridida) was investigated using phylogenetic analysis involving 26 apomorphic character states rooted with composite Falcaustra and quimperiid outgroups. A single cladogram was produced, with a consistency index of 0.867 (30 steps). Megalobatrachonema sensu Chabaud, 1978 was found to be polyphyletic, consisting of two groups corresponding to Megalobatrachonema, with type species M. nipponicum and doubtful species M. giganticum, and Chabaudgolvania, with type species C. terdentata and additional species C. elongata, C. waldeni, and C. moraveci.
Adult survival and recruitment and the explanation of an uneven sex ratio in a tortoise population
Authors: Hailey Adrian
Published: August 2008

Survival, recruitment, and dynamics of adult Testudo hermanni at Alyki (northern Greece) were studied from 1980 to 1988. Recruitment of adult males was greater than that of females owing to their shorter time to maturity (9 vs. 11 years); recruitment of subadults (6 years old) was equal in males and females. Mean annual survival was slightly greater in males (0.914) than females (0.877), equivalent to mean adult longevity values of 11.6 and 8.1 years, respectively. Excluding tortoises that die before maturity, male and female T. hermanni are mature for about 56 and 42% of their life, respectively. Generation time was roughly twice the age at maturity, and three times the age at which secondary sexual characters develop, a pattern which may apply to other tortoises. The combination of adult survival and recruitment should lead to a stable sex ratio (males/females) of 2.1. The adult sex ratio was higher than this, but decreasing, from4.1 in 1982to3.0 in 1986, with an increase in the female population; the number of males was stable. The observed sex ratio showed a similar decline and a further fall to 2.4 in 1988. The cause of the lower survival rate of females compared with males is proposed to be damage during courtship attempts. The courtship behaviour and related anatomy of T. hermanni are compared with those of T. graeca, a species with even population sex ratios. The level of male-induced female mortality would depend on population density; the increasing number of females during the study follows the approximate halving of population density in 1980.