bluuebunny/crossref_metadata_2025 huggingface dataset:
THE BIOSYNTHESIS OF RADIOACTIVE ARABINOSE, XYLOSE, AND GALACTOSE USING DETACHED WHEAT SEEDLINGS
Authors: Cowie Lillian M. , Krotkov G.
Published: August 2008

Five-day-old seedlings of wheat were placed in an atmosphere of C14O2 and permitted to carry on photosynthesis continually for 7 to 8 days. At the end of this time the leaves were extracted with 85% ethanol. The alcohol-insoluble residue was hydrolyzed with 1 N hydrochloric acid. The hydrolyzate was deionized, concentrated, and streaked on Whatman No. 3 MM paper. The sugars were separated by one-dimensional chromatography in butanol/pyridine/water and found to be present in the following relative amounts: glucose > xylose > arabinose > galactose.
THE PHYSIOLOGY OF HOST–PARASITE RELATIONS: III. THE PATTERN OF RESPIRATION IN RUSTED AND MILDEWED CEREAL LEAVES
Authors: Shaw Michael , Samborski D. J.
Published: August 2008

The first leaves of resistant (Khapli) and susceptible (Little Club) species of wheat were heavily inoculated with stem rust (Race 15B). After infection, oxygen consumption per unit dry weight increased two- to three-fold and then fell off again. The R.Q. remained close to 1.0 until the respiratory peak was reached and then declined to 0.80 to 0.85, at least in Khapli. The INR/OR values (approximately 1.2) suggest the operation of a Pasteur effect in uninfected tissue. With infected tissue there was little or no increase in NR as oxygen uptake rose and the INR/OR values declined steadily to about 0.2 to 0.3. The oxygen uptake of rusted, mildewed, and uninfected tissue was stimulated by 2,4-dinitrophenol. The percentage stimulation was reduced by infection. The smallest percentage stimulations were observed, after the respiratory peak had been passed, with infected tissue of Khapli, in which chlorosis and other degenerative changes developed quickly. The actual increases in oxygen uptake obtained with 10−5 M dinitrophenol were about the same for infected as for uninfected tissue, but, in Khapli, fell sharply after the respiratory maximum. Leaf-disks were incubated separately with glucose-1-C14, glucose-6-C14, and glucose-UL-C14, and the relative activities of the carbon dioxide produced were measured. The C6/C1 ratio showed a significant negative correlation with the oxygen uptake of rusted tissue, suggesting that the pentose phosphate pathway is of increased importance in infected tissue. The C6/C1 ratio was also reduced in the host tissue at the loci of mildew infections. In short term experiments dinitrophenol raised the C6/C1 ratio. The significance of the results is discussed and it is concluded that infection with rust or mildew not only raises the respiration rate but alters the pathway of respiration in the host tissue.
THEIEFFECT OF DARKNESS ON LESION PRODUCTION IN NICOTIANA GLUTINOSA L.
Authors: Weintraub M. , Kemp W. G.
Published: August 2008

Comparison, in the dark and light, of N. glutinosa plants inoculated with TMV indicates increased susceptibility in the dark. Rubbing with carborundum produces injury lesions similar to virus lesions, and so may give misleading results in virus assay studies.
THE INHERITANCE IN WHEAT OF A BLUE ENDOSPERM COLOR DERIVED FROM AGROPYRON ELONGATUM
Authors: Knott D. R.
Published: August 2008

The gene(s) for blue endosperm was found to be carried on an Agropyron chromosome which is not homologous to a wheat chromosome. The gene(s) is partially dominant and has a distinct dosage effect.
THE PHYSIOLOGY OF STOMATA: II. THE APPARENT ABSENCE OF CHLOROPHYLL, PHOTOSYNTHESIS, AND A NORMAL RESPONSE TO LIGHT IN THE STOMATAL CELLS OF AN ALBINO BARLEY
Authors: Shaw Michael
Published: August 2008

The chlorophyll content of the pure albino plants produced by self-fertilizing a strain of variegated barley is about 1.2 μg. per gram fresh weight. The stomatal guard cells of the albino plants are normal in structure, but do not contain detectable amounts of chlorophyll. Microradioautography of epidermal strips previously exposed to radioactive carbon dioxide in light and darkness did not reveal the localization of radioactivity which would be expected in the guard cells if they were capable of photosynthesis. Moreover, the "albino" stomata do not open normally in response to light or in a carbon-dioxide-free atmosphere. These observations support the view that normal, light-sensitive stomatal cells contain functional chloroplasts and that stomatal opening is promoted by the photosynthetic removal of free carbon dioxide in the mesophyll and in the guard cells.
THE EFFECT OF LIGHT AND TEMPERATURE ON THE GROWTH AND RESPIRATION OF BOTRYTIS SQUAMOSA
Authors: Stinson R. H. , Gage R. S. , MacNaughton E. B.
Published: August 2008

The fungus organism Botrytis squamosa Walker when maintained at constant temperature is unaffected by light levels as high as 100 ft-c for periods of several days and by levels of 250 ft-c for periods of a few hours. This is contrary to an earlier report which said that an illuminance of 70 ft-c would prevent growth of the organism. It is suspected that a combination of undetected temperature gradients and the variability of the organism lead to the earlier report of a light inhibition.The organism is temperature sensitive. No growth occurred at, or beyond, 30 °C. Maximum growth occurred at 23 °C, the lowest temperature used in the investigations.While all portions of the mycelial mass evolve some carbon dioxide, the most active evolution is generally around the circumference. Variations in age and circumference accounted for a considerable portion of the variability in the carbon dioxide evolution.Measuring techniques involved the use of thermocouples, a radiation thermopile and photronic cell, and an infrared gas analyzer.
THE UPTAKE OF A HOMOLOGOUS SERIES OF FUNGICIDES BY PLANT TISSUE AND FUNGAL SPORES
Authors: Somers E.
Published: August 2008

The uptake of 2,5-dimercapto-1,3,4-thiadiazole (DMTD) and its n-alkyl thioethers, ranging from methyl to octyl, by potato disks and fungal cells has been studied. The mineral oil/water partition coefficients of the compounds increased with increasing chain length to the amyl homologue and decreased for the higher members, an effect more marked when the compounds were almost completely unionized at low pH. At equimolar concentrations the uptake of the DMTD homologues by potato tissue was not dependent on alkyl chain length; maximum uptake was given with the amyl member. Experimental evidence indicates that the uptake by potato disks is, at least partially, a cell metabolic process.The uptake of the fungicide series by conidia of Aspergillus niger, Helminthosporium sativum, Monolinia fructicola, and Stemphylium sarcinaeforme increased with increasing length of alkyl side chain to a maximum with the amyl homologue and decreased for the hexyl, heptyl, and octyl members. Experiments with M. fructicola again indicated that the uptake was dependent on cell metabolism. No evidence was found that the compounds were structurally non-specific toxicants and it is suggested that their toxicity is due to chemical interaction in or through a lipophilic biophase of the fungal cell and that this process is dependent on cell metabolic activity. It appears likely that fungal spores are able to detoxify an appreciable portion of the fungicides either in the cell wall or within the protoplasm.
CYTOGENETICS OF SOLID STEM IN COMMON WHEAT: III. CULM MEASUREMENTS AND THEIR RELATION TO STEM SOLIDNESS IN MONOSOMIC LINES OF THE VARIETY S-615
Authors: Larson Ruby I. , MacDonald M. D.
Published: August 2008

Most monosomics of the solid-stemmed variety of common wheat, S-61S, were shorter than normal. Many had thinner culms, but monosomics XIII and XVI had thicker culms. Although the effect of loss of homoeologous chromosomes on culm dimensions was generally similar in S-615 monosomics and Chinese Spring nullisomics, the most extreme member of each group was not always the same in the two varieties. The differences between solid stem in monosomics and normal lines of S-615 were due to loss of the chromosome affecting pith production and not to secondary effects caused by changes in culm dimensions. Nevertheless, within lines of genetically similar plants there was a small but consistent association between short culm and solidness, between thin culm at the tops of internodes I, III, and IV and hollowness, and between thin culm in the center and lower parts of internode I and solidness. This has a bearing on interpretation of data in monosomic analysis of solid stem.
DORMANCY STUDIES IN SEED OF AVENA FATUA: I. THE POSSIBLE ROLE OF GERMINATION INHIBITORS
Authors: Black M.
Published: August 2008

When aqueous extracts of hull and caryopsis of Avena fatua are chromatographed, two inhibitory regions can be detected. These two inhibitors appear to be present in the hull and caryopsis in approximately equal amounts per unit weight of tissue. Evidence has been brought forward to show that the inhibitory effect of the hull in intact dormant seeds cannot be ascribed solely to the inhibitors present in the hull, nor does interference with gaseous exchange by this tissue account for its effect. Experiments have shown that isolated caryopses from dormant seeds germinate only when in contact with liquid water. Evidence from several experiments indicates that the hull may prevent leaching of inhibitors from the caryopsis which then allows of germination. It has been shown that inhibitors very readily diffuse out of the caryopsis on moist filter paper and that this process is retarded by the hull. Treatment with high oxygen concentrations, which promotes germination of very dormant seeds, appears to result in a reduction of inhibitor level before visible germination. In the induction of secondary dormancy under anaerobic conditions there is a marked increase in the total inhibitor level of the caryopses.
ANALYSIS OF THE HISTOCHEMICAL LOCALIZATION OF PEROXIDASE RELATED TO THE DIFFERENTIATION OF PLANT TISSUES
Authors: Fleet D. S. Van
Published: August 2008

Peroxidase is detectible in all tissues but is most reactive, in the basophilic cells of the histogens. Oxidation of applied phenols and aminophenols by peroxidase produces quinones and quinonediimines that are adsorbed by nucleic acids and other basophilic substances in the formative centers of primordia. Localized reactions for peroxidase occur in the axils of leaf primordia prior to bud formation and on the surface of apical meristems in a spiral pattern marking the points for the future development of leaf primordia. Peroxidase is detectible in advance of or accompanying cell division and declines after the division phase; decline of peroxidase at the end of the division phase is related to the increase of phenols, naphthols, and phenolases. Peroxidase declines in all tissues except the phloem; a continuous peroxidase system in the phloem connects primordia with adult tissue. The hypothesis is offered that the cellular units of the phloem peroxidase constitute a continuous system between primordia and adult tissue and is functional in catalyzing the reduction of hydrogen acceptors essential to cell division and the initiation of primordia.
SELECTIVE INHIBITION OF PHOTOSYNTHESIS
Authors: Lefrançois Marcel , Ouellet Cyrias
Published: August 2008

In the presence of ethanol or acetone at concentrations up to 10% by volume, photosynthetic fixation of C14O2 by Scenedesmus proceeds at nearly normal or enhanced rates, over periods of several minutes, into glycolic acid, glycine, alanine, serine, and an unknown compound. However, fixation into other compounds, such as phosphoglyceric, phosphopyruvic, and aspartic acids and the lipids, is suppressed over induction periods of several minutes. The results indicate that blocking of the photosynthetic cycle unmasks an alternate path of fixation. It is suggested that the initial step is the carboxylation of phosphoenolpyruvic acid. At a concentration of about 10−5 M, o-phenanthroline enhances the fixation into compounds which are connected with the tricarboxylic acid cycle, at the expense of the fixation in all other compounds. With increasing inhibition, alanine is in all cases the last labelled compound to vanish, as if some of it had an origin independent of that of the other products.
A RARE SEED-BORNE DISEASE OF WHEAT CAUSED BY PODOSPORIELLA VERTICILLATA
Authors: Wallace H. A. H.
Published: August 2008

A rare fungus, Podosporiella verticillata O'Gara, was isolated from a single seed in each of 13 samples of common and durum wheat grown during the period 1946–1949 in western Saskatchewan and Alberta. The fungus had not been reported previously in Canada. Helminthosporium cyclops Drechsler is a synonym of P. verticillata. Naturally infected seed did not germinate. When mature seeds of cereals were artificially inoculated, germination was unimpaired and healthy plants were produced. Inoculation of developing kernels in heads of wheat and panicles of oats resulted in apparently healthy seeds, but when these were placed on moist filter paper they either failed to germinate or produced stunted seedlings. This injury is apparently caused by a toxin produced by the fungus. The fungus is not likely to be of economic importance under western Canadian conditions.
NUTRITIONAL STUDIES ON THE GENUS HIRSUTELLA: I. GROWTH RESPONSE IN AN ENRICHED LIQUID MEDIUM
Authors: MacLeod D. M.
Published: August 2008

Quantitative comparative studies on the growth of Hirsutella gigantea in shaken yeast extract – dextrose medium have shown that the rate of growth and total yield is affected by the quantity of inoculum. The highest yield is obtained with an inoculum level ranging from 0.2 to 0.4 mg/50 ml; moreover results from repeated experiments tend to be relatively uniform. With smaller quantities of inoculum, i.e. 0.1 mg or less, the uniformity of growth among replicates is affected. An increase in the amount of inoculum above the optimum, while accompanied by a higher rate of growth, results in a gradual decrease in the total yield.With approximately 0.2 mg of inoculum the maximum yield, 673.4 mg of fungal mycelium, was obtained after 12 days' incubation in a medium containing 1.5% yeast extract and 2% dextrose.The fungus does not grow in a basal dextrose–salts medium with potassium nitrate or ammonium nitrate as the nitrogen source. The effectiveness of yeast extract indicates a requirement for organic nitrogen. Yeast extract may also act as a source of growth factors.
THE CONTROL OF GROWTH AND DEVELOPMENT IN RED CLOVER (TRIFOLIUM PRATENSE L.): III. ENDOGENOUS DIFFUSIBLE AUXIN
Authors: Cumming Bruce G.
Published: August 2008

Significant amounts of endogenous diffusible auxin have been obtained from apices and leaves of red clover plants and differences in endogenous diffusible auxin level have been related to characteristic differences in morphogenesis.Less diffusible auxin was obtained from the apices and leaves of autotetraploid than diploid plants of the same clone; a slower rate of growth was observed in the tetraploids.Changes in the diffusible auxin level can be brought about by variations in light that occur in a normal growth situation. Greater amounts of diffusible auxin were obtained under longer daylengths. Lesser amounts of diffusible auxin were obtained from plants that were shaded. A greater amount of diffusible auxin was obtained from apices when in light than in darkness.Application of 2,3,5-triiodobenzoic acid lowered the diffusible auxin level within the plant and interfered with normal polarity.An interaction between application of 3-indoleacetic acid, light intensity, and diffusible auxin level has been observed. This interaction is most readily explicable on the postulation, based on indirect evidence, that a mechanism for the regulation of endogenous free auxin level may exist in red clover whereby an auxin production system can be linked with some adaptive system, possibly IAA oxidase, that decreases the amount of endogenous free auxin.
EVIDENCE FOR NEGATIVE FEEDBACK IN THE CONTROL OF ETHANOLAMINE BIOSYNTHESIS IN EXCISED TOMATO ROOTS
Authors: Boll William G.
Published: August 2008

The isolation of a clone of excised tomato roots (clone R3), and the modifications of White's medium necessary for successful culture of this clone, are described. The medium includes pyridoxin. Either ethanolamine, dimethylethanolamine, glycine, L-serine, L-valine, DL-norleucine, or L-isoleucine (and possibly L-tryptophane) replaced pyridoxin to a greater or lesser extent. L-Alanine, L-lysine, and L-threonine did not replace pyridoxin. The replacement of pyridoxin by ethanolamine is not dependent upon the carry-over of pyridoxin in the inoculum and clone R3 has been subcultured for over a year in a medium containing ethanolamine but no added pyridoxin. Explanations of this fact are given.Nutritional experiments are described in which ethanolamine and amino acids, which will also partly replace pyridoxin, were supplied together in the absence of pyridoxin. The results support the hypothesis that exogenous ethanolamine leads to the loss of a vitamin B6dependent enzyme necessary for the biosynthesis of ethanolamine. The results are of incidental interest when considering the use of complex additives (e.g. yeast extract) in culture media, and to the explanation of toxicity of natural metabolites.
ANTHRACNOSE OF CANNING TOMATOES IN ONTARIO
Authors: Illman W. I. , Ludwig R. A. , Farmer Joyce
Published: August 2008

Colletotrichum atramentarium (not C. gloeosporioides or ? C. phomoides as frequently stated) was found to be the predominant cause of ripe fruit rot in canning tomatoes in Ontario and the adjoining regions of the United States. Infection by the organism occurred readily on all parts of the plant including the fruit. Development of the organism in the plant ceased, however, after a very brief initial period of rapid growth and remained latent until the surrounding host tissues became senescent.Latency in the fruit could be partially overcome by a period of low temperature storage and symptom expression thus obtained in green fruit. The ability of the organism to establish itself in the xylem vessels of the root and stem was demonstrated. Here again, however, rapid development of the organism was of only short duration.The significance of these findings is discussed and attention is drawn to a number of features of the disease that require further clarification.
THE ESTIMATION OF NUCLEIC ACIDS IN SOME ALGAE AND HIGHER PLANTS
Authors: Smillie Robert M. , Krotkov G.
Published: August 2008

Several current methods for the extraction and estimation of nucleic acids in biological materials were applied to Euglena and other plants. The efficiency of both the preliminary extractions for acid-soluble-P and lipid-P and the subsequent extraction of the nucleic acids was studied. A relatively high acid concentration (15% TCA) was required to directly extract all the acid-soluble phosphates. These conditions appeared to remove a small amount of the RNA. Lower acid concentrations as used in the Ogur–Rosen method (2% PCA) failed to extract all the acid-soluble phosphates. By using a modification of the Ogur–Rosen initial extraction method, the acid-soluble phosphates were quantitatively extracted without loss of RNA. After removal of the acid-soluble phosphates and lipid phosphates, the plant nucleic acids were quantitatively extracted by either the Schmidt–Thannhauser or Schneider methods. In many of the plants tested, the presence of pentose-containing polysaccharides, protein degradation products, or polyphosphate (algae only) interfered in estimations based on either the Schneider or Schmidt–Thannhauser procedures. Such interfering substances in the Schmidt–Thannhauser method were eliminated by the use of an anion exchange resin. Details are given of a modified Schmidt–Thannhauser procedure which should be suitable for a wide range of plants. The modified procedure may be simplified for Euglena and some higher plant tissues depending on the nature and quantities of interfering substances present. Methods are also given for the quantitative separation of plant RNA nucleotides by paper chromatography and by ion exchange paper chromatography.
THE CYTOLOGY OF THREE HYBRIDS INVOLVING HORDEUM JUBATUM L.: THE CHIASMA DISTRIBUTIONS AND THE OCCURRENCE OF PSEUDO RING-BIVALENTS IN GENETICALLY INDUCED ASYNAPSIS
Authors: Wagenaar E. B.
Published: August 2008

Three hybrids, two of Hordeum jubatum L. × Secale cereale L. var. Prolific, and one of H. jubatum × H. bulbosum L., were examined cytologically. The two genomes of H. jubatum showed autosyndesis in the H. jubatum × S. cereale hybrids. It was concluded, therefore, that H. jubatum has two closely related genomes.One of the H. jubatum × S. cereale hybrids displayed weak asynapsis. The H. jubatum × H. bulbosum hybrid, on the other hand, showed strong asynapsis, although the prophase pairing was almost complete. It was concluded that the asynapsis of this latter hybrid was due to interaction of genes of the H. jubatum and the H. bulbosum genomes.The chiasma distributions of the hybrids were tested for randomness by Gaul's formula. It was found that the chiasma distributions of the H. jubatum × S. cereale hybrids followed a random pattern, whereas in the H. jubatum × H. bulbosum hybrid the distribution was disturbed by a secondary effect. Cytological observations and theoretical considerations led to the conclusion that the occurrence of pseudo ring-bivalents had disturbed the apparent chiasma distribution in the H. jubatum × H. bulbosum hybrid. A theory of the origin of pseudo bivalents and an evaluation of Gaul's formula is presented.
CHROMOSOME NUMBERS IN SOME MOSSES FROM QUEBEC
Authors: Al-Aish Matti , Anderson Lewis E.
Published: August 2008

The results of chromosome studies of five species of mosses from the Mont Tremblant area of Quebec are presented. The chromosome numbers of two species, Plagiothecium roeseanum (Hampe) B.S.G., with the number n = 20, and Polytrichum ohioense Ren. & Card., with the number n = 14, are reported for the first time. Both species are established tetraploids with no evidence of chromosome irregularities in meiosis. Chromosome numbers reported for the other three species are as follows: Dicranum rugosum (Hoffm.) Brid., n = 12; Dicranum scoparium Hedw., n = 12; and Plagiothecium denticulatum Hedw., n = 20. The population of D. rugosum that was studied did not possess small precociously separating bivalents as have been reported for European populations. The close resemblance of the chromosome complements of P. denticulatum and P. roeseanum is in line with the close taxonomic relationship between the two species. Cytotaxonomic implications are discussed under each species.
MEASUREMENT OF OXIDATION–REDUCTION CONDITIONS IN WHEAT LEAF SAP BY A POTENTIOMETRIC METHOD
Authors: Kaul Rudolf , Shaw Michael
Published: August 2008

Extracts from primary leaves of Little Club wheat, prepared under anaerobic conditions, gave oxidation–reduction potentials in the range of −180 mv to −140 mv at pH 6 when measured potentiometrically with prepolarized platinum electrodes. These poorly poised potentials are believed to represent a flavin system. By mixing mediators (e.g. methylene blue and riboflavin) with the extracts stable average potentials were achieved. These ranged from −70 to +70 mv. Coleoptiles and very young primary leaves exhibited relatively low average potentials, which climbed to a steady level in 8 to 10 days after sowing. This change was accompanied by a quantitative shift between three poising systems found in the leaves by redox titrations. The results suggested that ascorbic acid becomes the dominating redox system in extracts from mature leaves. At senescence, indicated by yellowing, a new system dominates the redox background. This exhibited quinonic properties.
THE EFFECTS OF ETHIONINE ON SOME PLANT GROWTH SYSTEMS
Authors: Lowther Ruth L. , Boll William G.
Published: August 2008

Ethionine (CH3∙CH2∙S∙CH2∙CH2∙CH∙NH2COOH) was tested on six plant growth systems: (a) growth of lateral buds on decapitated dwarf beans, (b) rooting of excised, etiolated bean hypocotyls, (c) linear growth and final cell size of primary roots of wheat, (d) growth of hypocotyl and roots of flax seedlings, (e) growth of sections from etiolated pea shoots, and (f) expansion of leaf disks from etiolated beans. Ethionine stimulated growth in each of these systems with the possible exception of (a) and (d). The work on the rooting of etiolated bean hypocotyls includes the description of a new rooting test.Pretreatment of pea sections with manganese lowered or prevented the stimulatory effect of ethionine.Expansion of etiolated bean leaf disks was not increased by ethylenediaminetetraacetic acid, penicillin G, and the ‘antiauxins’ α (2,4-dichlorophenoxy)- isobutyric acid, α(p-chlorophenoxy)isobutyric acid, and 2,3,5-tri-iodobenzoic acid whereas maleic hydrazide, o-chlorophenoxyisobutyric acid, m-methyl phenoxyacetic acid, and 2,4,6-trichlorophenoxyacetic acid (TCPAA) stimulated expansion. TCPAA, at 10 mg/liter, completely replaced the stimulatory effect of cobalt on light-treated disks. The peculiar dose–response curve and some morphogenetic effects with TCPAA are described.Ethionine, cobalt, and TCPAA all inhibit chlorophyll synthesis in leaf disks exposed to light. TCPAA also causes a loss of yellow pigment in disks kept in the dark.Depending upon the test system, ethionine simulates the effects of auxin or ‘antiauxins’. Metabolic studies with ethionine are briefly reviewed. Some connections between the known effects of ethionine and theories of auxin action, and the possible significance of ethionine as an inhibitor of adaptive enzyme synthesis, are pointed out.
ONTOGENETIC TRENDS IN CONIFER CAMBIUM WITH RESPECT TO FREQUENCY OF ANTICLINAL DIVISION AND CELL LENGTH
Authors: Bannan M. W.
Published: August 2008

Through the growth of the first few years, when the perimeter of the stem is fast expanding, the multiplicative pseudotransverse divisions in fusiform cambial cells occur in relatively rapid sequence, the ratio of survival of newly formed cambial cells is high, and continuous increase in mean cell length ensues. Accommodation of the cambium to circumferential expansion is thus facilitated. With increasing age and diminishing rate of perimeter growth the frequency of pseudotransverse division declines, the survival rate of new-formed cambial initials drops, and increase in cell length slackens. This gradual flattening off may continue through to the final growth, but more often fluctuations in rate of anticlinal division and cell length arise in the middle to late growth, these not always exhibiting close interrelationship. Sometimes high rates of pseudotransverse division occur in the late growth which are accompanied by only moderate reductions in cell length.
THE MOVEMENT OF INJECTED DYE SOLUTIONS IN HEALTHY AND NEEDLE-BLIGHTED WHITE PINE TREES
Authors: Linzon S. N.
Published: August 2008

The movement of dye solutions in stems of white pine trees, Pinus strobus L., was studied by injection methods. Of several solutions used, a dilute aqueous solution of acid fuchsin was the best indicator of water absorption and movement in the tree. One-hole injections permitted a better assessment of the movement of solutions in the tree than girdle injections. Solution absorption in white pine through a girdle injection locus was observed to average about one liter per hour at the start of the injection period and to diminish with time. Increasing amounts of solution were absorbed and advanced higher in the tree with increasing numbers of daylight hours. Solution absorption and movement in the tree were depressed during night hours. Height of movement of the solution in the tree was unaffected by the size of the injection incision. Exposing the outer sapwood by cutting a "window" through the bark permitted the observation of the actual movement of a dye solution in a living tree.The effect of needle blight on solution movements was investigated by simultaneous injections of paired healthy and diseased pine trees. Smaller quantities of solution were taken in by diseased trees, per unit time. The rates of solution uptake, however, were similar in needle-blighted and healthy trees.
THE SPORULATION OF HELMINTHOSPORIUM ORYZAE AS AFFECTED BY EXPOSURE TO NEAR ULTRAVIOLET RADIATION AND DARK PERIODS
Authors: Leach Charles M.
Published: August 2008

Investigated was the interrelation of near ultraviolet radiation (3100–4000 Å) and darkness to the sporulation of Helminthosporium oryzae. When H. oryzae was grown on potato dextrose agar at 70–75° F and irradiated at intensities of 76–470 μw per cm2: (1) Near ultraviolet stimulated sporulation while visible light did not. (2) Conidiophore development was initiated under irradiation but not in darkness. Both continuous irradiation and intermittent irradiation (2-hour ultraviolet, 2-hour dark cycle) caused formation of conidiophores. (3) Conidia developed only when a period of irradiation was followed by a period of darkness. No conidia developed under continuous irradiation or in continuous darkness. (4) Under a single cycle treatment, the minimum dark period necessary for conidial development following an extended period of continuous irradiation was [Formula: see text] hours. (5) Under a single cycle treatment, the minimum exposure to ultraviolet followed by an extended dark period necessary to cause moderate to profuse conidial development was 4 hours, although conidia did form sparsely after shorter exposures. (6) Under alternating cycles of dark and irradiation of 2, 4, 6, 8, and 12 hours (e.g. 2 hours dark, 2 hours ultraviolet, etc.), conidia developed under the 8- and 12-hour cycles, but not under the shorter cycles. Conidia developed under shorter cycles when the cyclical exposures were followed by a dark period of 12 hours. (7) Continuous irradiation of nutrient broth cultures caused a significant increase in dry weight growth over cultures kept in darkness.
A REVISION OF THE GENUS PETRIELLA
Authors: Barron G. L. , Cain R. F. , Gilman J. C.
Published: August 2008

A reappraisal is made of the genus Petriella Curzi. The type species, Petriella asymmetrica, is found to be identical with a species previously described as Microascus sordidus Zukal. The latter species is transferred to Petriella as a new combination, and one new species, P. guttulata, is described. A synopsis of the genus, with five species, is presented. The additional three species are P. setifera, P. lindforsii, and P. boulangeri.
THE INHERITANCE AND HISTOLOGY OF A CHLOROPHYLL-DEFICIENT CHARACTER IN MEDICAGO SATIVA L.
Authors: Childers W. R. , McLennan H. A.
Published: August 2008

Further support for tetrasomic inheritance in alfalfa was shown from genetic studies of a chlorophyll-deficient seedling character. The character was determined by a single recessive gene for which the symbol Viridis-1 or v1is proposed. At the mature-plant stage, low and intermediate classes for chlorophyll production were observed. Histological examination and chlorophyll analyses confirmed this classification. The low-chlorophyll-producing class was characterized by a lack of plastids in the leaf blades although some plastids occurred in mesophyll tissue around the midrib. The intermediate chlorophyll-deficient class was characterized by yellowish-green leaf blades, associated with colorless palisade cells that overlay a single continuous layer of mesophyll cells in which the plastids were well developed.
THE EFFECT OF PHOTOPERIOD AND NITROGEN ON THE GROWTH AND DEVELOPMENT OF SEEDLINGS OF JACK PINE
Authors: Giertych M. M. , Farrar J. L.
Published: August 2008

Nine seed lots of Pinus banksiana Lamb. and one of P. contorta var. latifolia Engelm. were grown for 115 days on five nitrogen levels and two photoperiods. The nitrogen levels were: zero N—no nitrogen, [Formula: see text], [Formula: see text], 1N—203 p.p.m., and 2N—406 p.p.m. The two photoperiods were a long-night photoperiod (10-hour day) and a broken-night photoperiod (9.5-hour day followed by 0.5-hour light break in the middle of the dark period). The plants, five per vessel, were analyzed for their response to treatments in terms of growth, development, and nitrogen content.(1) The breaking of the night doubled the height, total dry weight, and leaf weight and increased root weight and nitrogen absorption, but it lowered the number of fresh, active root tips, the proportion of the plant in root tissue, and the nitrogen concentration, inhibited production of secondary leaves, and delayed winter bud formation.(2) The increase in nitrogen level in the medium lowered the percentage of fresh, active root tips, the proportion of the plant in root tissue, and the production of winter buds; it increased the content and concentration of nitrogen in the plants. Up to a certain maximum (about [Formula: see text]), it increased the dry weight and height of the plants.(3) The interrelation of growth and developmental stimuli is discussed. It is suggested that growth is an important factor in controlling development.
SEROLOGICAL PROPERTIES COMMON TO DIFFERENT ISOLATES OF SOME STONE-FRUIT VIRUSES
Authors: Tremaine J. H. , Willison R. S.
Published: August 2008

Virus entities in cucumber associated with cherry yellows, green ring mottle, and necrotic ring spot of sour cherry; tatter leaf of sweet cherry; and prune dwarf were found to be serologically related but not identical. The virus antigens were compared in gel-diffusion precipitin tests with antisera prepared from both cucumber leaves and infected cherry petals.
SEROLOGICAL AND PHYSICAL PROPERTIES OF SOME STONE-FRUIT VIRUSES: NON-VIRUS PARTICLES ASSOCIATED WITH INFECTION
Authors: Willison R. S. , Tremaine J. H. , Weintraub M.
Published: August 2008

Cherry yellow virus, isolates Y.2 and Y.4, and necrotic ring spot virus, isolates N.4 and N.5, purified either from cucumber leaves or from sour cherry petals, were characterized by antigenically related particles that sedimented at approximately 72 S. Some preparations of each virus derived from either host also contained either a 35 S or a 22 S component usually having a low nucleic acid content. Such preparations were shown by the agar gel double-diffusion technique to contain two antigens, V and Q, that were only distantly, if at all, related. The 72 S component is associated with the V antigen, whereas the 22 S and 35 S components are tentatively considered to be two forms of the Q antigen. The Q antigen could also be detected in clarified expressed sap of infected cucumber tissue, but not in that of healthy cucumber nor in extracts prepared from healthy sources by methods used to purify the viruses. The Q antigen is thus associated with infection, but its origin has not yet been satisfactorily determined.
STUDIES OF COPROPHILOUS ASCOMYCETES VII. PREUSSIA
Authors: Cain Roy F.
Published: August 2008

The Plectascales and Perisporiales are both artificial taxa each consisting of a miscellaneous assemblage of unrelated genera. The generic name Perisporium is not valid for species of Ascomycota (Ascomycetes). The valid name for those species which produce ascocarps is Preussia Fuckel. The ascocarps are non-ostiolate (cleistothecia) and their development is the same as that in the Loculo-ascomycetes (producing a pseudothecium). The ascocarp of Preussia is thus a cleistothecial pseudothecium. The genus most closely related to Preussia is Sporormia and the two may be included in the same family Sporormiaceae. Preussia is not included in the Phaeotrichaceae on account of the elongated germinal slit and lack of hairs on the peridium of the ascocarp. Twelve species are included with descriptions and illustrations. The type species of Preussia is P. funiculata Fuckel. Three species are transferred to this genus from Perisporium. These are P. punctata (Auersw.) Sacc., P. typharum Sacc, and P. vulgare Corda. One species is transferred from each of the following genera: Sporormia (Sp. fleischhakii Auersw.), Muellerella (M. nigra Routien), Pycnidiophora (P. dispersa Clum), Anixiopsis (A. multispora Saito and Minoura), and Thielavia (T. indica Chattop. and Das Gupta). The following three species are described as new: P. isomera, P. terricola, and P. purpurea.
THE INFLUENCE OF AGING OF SEED ON THE DEVELOPMENT OF LOOSE SMUT IN BARLEY
Authors: Russell R. C.
Published: August 2008

For several years after their production, 15 stocks of barley seed, infected with Ustilago nuda (Jens.) Rostr., produced approximately the same average percentage of smutted plants in growth tests as the average percentage of infected embryos found in the seed. As the seed became older, this was no longer true. Some samples produced less smut after six years, while others continued to produce similar amounts up to the ninth year, but eventually all samples produced decidedly lower percentages of smut. The average percentage of smutted plants in crops grown from these samples became less with each succeeding year after the sixth in nearly all instances. In the stocks of barley seed studied, the average amount of smut in the growing crop declined from about 14% initially to only 3.2% at the end of the 11-year period.The main reason for the decline in percentage infection was the successively larger proportions of infected seeds that failed to germinate as the seed became aged, as compared with the slower loss of viability in the healthy seeds. A close correlation was found between the length of time required for aged seeds to germinate and the percentage of such seeds carrying smut in their embryos.
MOSSES OF THE PRAIRIES OF WEST-CENTRAL CANADA
Authors: Bird C. D.
Published: August 2008

A total of 83 taxa of Musci are enumerated from the prairies of Alberta, Saskatchewan, and Manitoba. These are composed of 36 soil-dwelling species, 21 that occur on rotting vegetation, 8 aquatics, 6 rupestral, and 3 corticolous. A large number of new provincial records are reported as well as the species Mnium arizonicum, new to Canada. None of the species are endemic to the prairies and most attain greater abundance in neighboring wooded regions. The ecology of the region and early collections are discussed.
SOME EFFECTS OF ARTIFICIAL DEFOLIATION ON THE GROWTH OF JACK PINE (PINUS BANKSIANA LAMB.)
Authors: O'Neil L. C.
Published: August 2008

Young jack pine (Pinus banksiana Lamb.) were defoliated manually to measure the effects of defoliation on growth of this species, and to determine the relative efficiency of foliage of different ages with respect to growth. The removal of 2-year-old or 3-year-old foliage had no appreciable effect on tree growth, but their joint removal reduced height growth. Height growth was also reduced by the removal of 1-year-old foliage. Current foliage was found essential for the maintenance of normal height, diameter, and shoot growth; in addition, its removal induced high bud mortality, the production of profuse adventitious growth, and a reduction in the rate of shoot elongation. Trees deprived of all but current foliage showed marked reductions in height, diameter, and shoot growth. Complete defoliation resulted in tree death shortly thereafter. Growth reductions resulting from some of the treatments approximated that following defoliation by the Swaine jack-pine sawfly (Neodiprion swainei Midd.). Also, the present results are compared with those obtained by several other workers in this field.
TAXONOMY AND MORPHOLOGY OF POTEBNIAMYCES BALSAMICOLA SP. NOV. ASSOCIATED WITH A TWIG AND BRANCH BLIGHT OF BALSAM FIR IN QUEBEC
Authors: Smerlis E.
Published: August 2008

An undescribed ascomycete and its imperfect stage, associated with a twig and branch blight of balsam fir, Abies balsamea (L.) Mill., was investigated. Both stages were described and the fungus named Potebniamyces balsamicola sp. nov. Relationship between the two stages was established by cultural studies. Potebniamyces is the new name proposed to replace the preoccupied generic name Phacidiella Potebn.
THE RHIZOSPHERE EFFECT OF MYCORRHIZAL AND NON-MYCORRHIZAL ROOTS OF YELLOW BIRCH SEEDLINGS
Authors: Katznelson H. , Rouatt J. W. , Peterson E. A.
Published: August 2008

A study of the surface microflora of mycorrhizal and non-mycorrhizal roots of yellow birch seedlings has revealed distinct quantitative and qualitative differences. Higher bacterial counts and distinctly greater numbers of actinomycetes and of methylene-blue-reducing, sugar-fermenting, ammonifying, and fluorescent-pigment-producing bacteria were found on the former. The percentage incidence of bacteria growing optimally in a simple mineral–glucose medium was greater on normal roots whereas bacteria requiring complex nutritional factors appeared to be relatively more numerous on the mycorrhizal surface. Species of Pythium, Fusarium, and Cylindrocarpon predominated on, and Mycelium radicis (?) was absent from, normal roots, whereas, on mycorrhizal roots, Penicillium and other rapidly growing fungi as well as Mycelium radicis (?) were numerous and Pythium and Fusarium species absent. These results are discussed in relation to the nutrition of mycorrhizal and non-mycorrhizal roots.
INOCULATION OF DOUGLAS FIR ROOTS WITH PORIA WEIRII
Authors: Wallis G. W. , Reynolds G.
Published: August 2008

A method for the inoculation of Douglas fir roots with Poria weirii using Douglas fir, alder, maple, and oak wood for preparing the inoculum is described. When the deciduous wood was used as the food base on which the fungus was grown, a higher percentage of infection was achieved than when either Douglas fir stem or roots were used. Six months was sufficient time for the fungus to become well established on the bark surface; penetration of healthy bark occurred in 12 months. Spread of the fungus to adjacent roots at points of root contact was noted. Growth of mycelium on the bark surface was usually well in advance of infection in the wood. Poria mycelium continued to grow vigorously during the fall and winter months of the study period.
EFFECTS OF PETROLEUM OILS ON THE CARBON DIOXIDE UPTAKE IN THE APPARENT PHOTOSYNTHESIS OF PARSNIP AND MUSTARD
Authors: Helson V. A. , Minshall Wm. Harold
Published: August 2008

The herbicidal oils, petroleum naphtha, boiling range 149° to 204 °C, the naphthene–paraffin fraction of petroleum naphtha, undiluted n-dodecane, 25% p-cymene in paraffinic oil, and 15% tetrahydronaphthalene in paraffinic oil, caused an immediate decrease in apparent photosynthesis of both parsnip and mustard to near the respiration level. The photosynthesis of parsnip began to recover by 1 hour and was near 70% of normal with no visible injury by 24 hours after application of oil. With mustard, there was a slight temporary recovery during the first hour but then the photosynthesis completely ceased with the death of the leaves. Paraffinic oil containing 15% p-cymene was not selective, as the photosynthesis of mustard recovered to 40% of normal by 24 hours after application of the oil.A non-herbicidal, paraffinic oil, boiling range 204° to 260 °C, immediately decreased the apparent photosynthesis of both parsnip and mustard to the compensation point. The photosynthesis of both plants began to recover within 1 hour after application of the oil and was approaching normal by 24 hours, with no visible injury.
NOTES ON PLANT DISTRIBUTION IN THE ROCKY MOUNTAINS OF ALBERTA
Authors: Ogilvie R. T.
Published: August 2008

Three kinds of variability in the Rocky Mountain flora of Alberta are considered. The flora is composed of species with two gross distribution patterns: the boreal element and the cordilleran element. There are minor floristic differences from valley to valley; such differences involve the sporadic occurrence of certain species in different valleys. Main consideration is given to another type of floristic variability which involves a major floristic difference between the southern part of the mountain region and the northern part.The Crowsnest–Waterton area in the southern part of Alberta is distinctive climatically and phytosociologically from the rest of the Rocky Mountain region of Alberta. Moreover, a large number of plant species and some animal taxa occur in Alberta only in this area. Two possible features are suggested as being responsible for the distinctiveness of the southern area: the climatic effects of the occurrence of the area within a major storm track; and the existence of an adjacent unglaciated area which, during Pleistocene, could have served as a refugium for taxa which subsequently expanded in the southern area.
POVERTY WEED, IVA AXILLARIS, IN CANADA AND THE UNITED STATES
Authors: Bassett I. J. , Mulligan G. A. , Frankton C.
Published: August 2008

Evidence is presented that the western North American plant, Iva axillaris Pursh, consists of two populations which are recognized by the authors as subspecies. Subspecies axillaris, 2n = 36 and 54, is found only east of the Continental Divide and ssp. robustior comb, nov., 2n = 36 and 54, found mainly west of the Divide. A key is presented to show the differences between the two subspecies. Pollen morphology and seed production are discussed.
CHROMOSOMAL CONTROL OF ENZYME SYNTHESIS
Authors: Bonner James , Huang Ru-Chih C.
Published: August 2008

not available
THE EFFECT OF LIGHT QUALITY ON THE PRODUCTS OF PHOTOSYNTHESIS IN GREEN AND BLUE-GREEN ALGAE, AND IN PHOTOSYNTHETIC BACTERIA
Authors: Hauschild A. H. W. , Nelson C. D. , Krotkov G.
Published: August 2008

The effect of light quality on the products of photosynthesis has been studied in two species of green algae, Chlorella pyrenoidosa and Scenedesmus acuminatus, the blue-green alga Microcystis aeruginosa, and the photosynthetic bacterium Chromatium sp.The test organism was placed in C14-bicarbonate and illuminated at saturation intensities of red, red plus supplementary blue, blue alone, or white light. After 30 minutes, the distribution of C14among the products of photosynthesis was determined using the techniques of paper chromatography and autoradiography.At a high concentration of cells of Chlorella pyrenoidosa, blue light caused an increase in C14in aspartic, glutamic, fumaric, and malic acids and a decrease in sucrose and phosphate esters, although the rate of photosynthesis remained the same. At a low concentration of cells, similar changes were found, and these were accompanied by an increase in the rate of photosynthesis.Similar changes in the distribution of C14due to blue light were found also in Scenedesmus. In Microcystis, a substantial increase in C14due to blue light was found only in glutamic acid. The rate of photosynthesis remained the same in both organisms.The results indicate that the nature of the effect of blue light is the same in all of these organisms and in Chlorella vulgaris which was studied previously.Pretreatment in darkness is a prerequisite for a pronounced effect of blue light on the products as well as the rate of photosynthesis.No effect of light quality was found in Chromatium.
RECHERCHES SUR LA RÉSISTANCE DE L'ORME D'AMÉRIQUE AU CERATOCYSTIS ULMI
Authors: Ouellet Charles-Eugène , Pomerleau René
Published: August 2008

The selection conducted at L'Assomption, P.Q., from 1950 to 1963, has confirmed the very high susceptibility of the white elm (Ulmus americana L.) to the attack of Ceratocystis ulmi (Buis.) C. Moreau and the absence of resistant strains in nature. Thermal neutrons or X-ray treatment of seeds has not appreciably modified seedlings reaction to infection, except in 4 cases out of almost 150,000 in which no symptoms were apparent before the fifth annual inoculation or more. One individual has resisted nine consecutive tests and its cuttings did not take the infection after two assays. Resulting from a mutation produced by X-rays, this vigorous clone has a normal foliage but is of a smaller size than other elms of the same age. This case of immunity in the white elm is related to that of the Asiatic species and certain European strains also of slow-growing habit and resistant.
STUDIES OF WESTERN TREE RUSTS: VI. THE AECIAL HOST RANGES OF MELAMPSORA ALBERTENSIS, M. MEDUSAE, AND M. OCCIDENTALIS
Authors: Ziller Wolf G.
Published: August 2008

Results from controlled inoculation experiments show that conifers of six genera (Abies, Larix, Picea, Pinus, Psendotsuga, and Tsuga) are susceptible to the poplar (Populus) rusts of western Canada. Twenty-one new host records are established. It is suggested that Melampsora albertensis Arth. be reduced to synonymy with M. medusae Thüm., because they appear to be indistinguishable from each other in morphology, life history, host range, and host reaction.