bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of soil and air temperature on soluble sugars and growth of white spruce (Picea glauca) seedlings
Authors: Chalupa V. , Fraser D. A.
Published: August 2008

Qualitative and quantitative analyses of soluble sugars were conducted on needle and root samples of 17-month-old white spruce seedlings grown for the last 5 months at 50°, 70°, 80°, 90°, and 100 °F soil temperatures under continuous light in a greenhouse at an air temperature of 70 °F. Additional samples were taken when seedlings grown under these conditions were transferred for 1 month to a cold room at 34 °F under continuous light. Shoot and root growth was also studied on newly germinated seedlings exposed to soil–air temperatures of 65°–70°, 70°–70°, 80°–70°, and 90°–70 °F under continuous light for 8 months.An increase in sugars per unit dry weight, a greater apical growth, and a higher shoot–root ratio were associated with the 50°–70 °F and 65°–70 °F soil–air temperatures. The seedlings exposed for 1 month to soil–air temperatures of 34°–34 °F showed a considerable increase of soluble sugars, especially of the higher oligosaccharides from the raffinose family, when compared with those grown at 70 °F air temperature and varying soil temperatures. When seedlings are exposed to low temperatures, even at the period of budbreak, the change in the composition and amount of sugars is similar to that established under natural conditions in the fall.
Delimitation of the genus Avena (Gramineae)
Authors: Baum Bernard R.
Published: August 2008

An historical sketch of the different opinions concerning the generic limits of Avena and its relationships among other closely related genera of the tribe Aveneae is given. Advancement indexes of Avena and its closest allies were calculated. It is found that Avena possesses many primitive characters and in this respect is most closely allied to Arrhenatherum and Helictotrichon. The genera Amphibromus, Deschampsia, Trisetum, and Ventenata possess a greater number of more advanced characters and are considered to be more distantly allied with Avena. Diagnostic characters for Avena have been assessed. Avena macrostachya, a perennial species, has been included together with the annual oats within the generic limits of Avena. A full description of the genus is given.
The development of the ovule and megagametophyte in Rhexia mariana
Authors: Etheridge Albert L. , Herr Jr. J. M.
Published: August 2008

The ovules of Rhexia mariana are bitegmic and anatropous or rarely atropous. Periclinal divisions in the nucellar epidermis at the micropylar end produces a nucellar cap. A terminal pore in the nucellus is formed by the suppression of anticlinal divisions in the epidermis and subsequent separation of the cells during nucellar enlargement. A single hypodermal archesporium divides, producing a primary parietal cell and primary sporogenous cell. The primary parietal cell establishes a prominent parietal tissue as the primary sporogenous cell differentiates into the megasporocyte. Two prominent nucleoli that consistently appear in the archesporium persist in the primary sporogenous cell and the megasporocyte. Meiosis produces a tetrad of megaspores in either linear or approximately T-shaped arrangement. Cells of the nucellus adjacent to the sporogenous cell, megasporocyte, and tetrad rarely give rise to megagametophytes aposporically. The chalazal megaspore functions in megagametogenesis. Shortly after the first nuclear division, vacuoles migrate and coalesce between the nuclei. Two more nuclear divisions establish the four- and eight-nucleate megagametophytes. The chalazal nuclei are situated laterally and are noticeably smaller than the micropylar nuclei in both four- and eight-nucleate stages. The two polar nuclei remain in close contact, usually near the egg apparatus, but sometimes near the center of the megagametophyte. The three antipodal nuclei are ephemeral with degeneration completed by the time the egg apparatus is established. Orientation of the egg apparatus places the synergids on the side of the megagametophyte adjacent to the funiculus and the egg cell on the opposite side. The similarities and differences in ovule and megagametophyte development between Rhexia mariana and the tropical representatives of Melastomataceae previously investigated are discussed.
Use of the Cionco model to obtain further information on the nature of leaf boundary layers
Authors: Hunt L. A.
Published: August 2008

The Cionco model for air-flow within a foliage canopy was used to estimate the diffusion resistance of the boundary layer around the uppermost leaves in a corn crop. The values were compared with others derived from a formula which represents transfer through a laminar boundary layer. These comparisons suggested that the boundary layer was either turbulent, or in a state of transition from laminar to turbulent.
Carbon dioxide compensation—its relation to photosynthetic carboxylation reactions, systematics of the Gramineae, and leaf anatomy
Authors: Downton W. J. S. , Tregunna E. B.
Published: August 2008

The carbon dioxide compensation concentration of members of the Gramineae and a few other plants was determined with an infrared CO2 analyzer. These results were then considered in relation to the new photosynthetic carboxylation pathway proposed by Hatch et al., rates of photosynthesis, grass systematics, leaf anatomy, and distribution of starch in the leaf. Plants possessing the new carboxylation pathway had low compensation values whereas those having the Calvin carboxylation reaction had high values. Low compensation plants also had a well-developed parenchyma bundle sheath containing a high concentration of chloroplasts which accumulated large amounts of starch. Little or no starch was present in the mesophyll cells. Cyperus was exceptional in that it also formed appreciable starch in the mesophyll. Those low compensation members of the Gramineae tested belonged either to the chloridoid–eragrostoid or the panicoid lines of evolution. A literature survey indicated that low compensation grasses have photosynthetic rates that are about double those of plants with photorespiration correlated with a temperature optimum for photosynthesis of about 35 °C. Those plants with photorespiration have optima within the range 10–25 °C. Some simple assay procedures proposed on the basis of the above correlations allow rapid determination of the physiological and biochemical status of plants with respect to photosynthesis.
Free amino acids of sunflower hypocotyl tissue during crown gall tumor development
Authors: Behki R. M. , Lesley S. M.
Published: August 2008

The concentration of each free amino acid present in hypocotyl tissue of sunflower seedlings was determined during the period following both sterile wounding and inoculation with either tumorigenic (strain 1025) or non-tumorigenic (strain IIBNV6) Agrobacterium tumefaciens. The concentration of the total free amino acids of hypocotyl tissue reached a maximum 68 hours after infection with strain 1025 and this level was 50% greater than that found in plants treated with strain IIBNV6. The total content of free basic amino acids increased to a peak value at 20 hours after infection by strain 1025 and this represented 1.4 to 3 times the level found in strain IIBNV6 inoculated seedlings at 20 hours.The amount of free proline decreased with time and it was essentially absent 164 hours after infection with strain 1025. At 2 months the concentration of free proline in the tumor tissue was greatly increased with 75% of the total free amino acids accounted for as proline.The free amino acid content of strain 1025 growing in either the presence or absence of an extract from wounded seedlings was measured and the results indicated no significant relationship between the plant and bacterial systems with regard to their free amino acid pools.
Morphogenic investigations on parasitic angiosperms. I. Cistanche tubulosa (Orobanchaceae)
Authors: Rangan T. S. , Rangaswamy N. S.
Published: August 2008

In Cistanche tubulosa (Orobanchaceae), a herbaceous obligate root parasite, the seed is tiny and contains a subglobose embryo that lacks differentiation into radicle, hypocotyl, cotyledons, and plumule. Seeds were axenically cultured to study germination and the morphogenesis of the embryo. Germination occurred only when coconut milk was supplied in the agar nutrient medium and was characterized by the activity of only the morphological radicular pole of the embryo, which formed a mass of tissue. Differentiation of the shoot bud occurred when this tissue was grown in the dark on a complex nutrient medium. The plumular pole of embryo did not contribute to the formation of the shoot bud, nor did the embryo attain bilateral symmetry and organ formation before germination.
Initiation and development of leaves in Douglas fir
Authors: Owens John N.
Published: August 2008

The initiation and development of the leaves of Douglas fir is described in detail. Leaf initiation is similar to that of other foliar organs and involves both protodermal and peripheral cells of the apex. Apical and subapical initials are present but active for only a short time. Most enlargement is a result of intercalary cell division and enlargement. A limited marginal meristem is present. No differentiation of tissues occurs before bud dormancy in the fall. Growth following dormancy shows the various tissues to mature at different rates and all tissues are fully mature when the leaf becomes dormant in the fall. Growth periodicity of the shoot apex and the length of the growing season are discussed. Initiation and development of leaves in relation to all other foliar organs in Douglas fir are compared.
Effect of moisture content on the sterilization of wood, under vacuum, by propylene and ethylene oxides
Authors: Smith Roger S.
Published: August 2008

Ethylene and propylene oxides were used, separately in a previously evacuated system, to disinfect heavily contaminated spruce blocks that had been conditioned to various moisture contents. Ethylene oxide (70% by volume), used on wood with a moisture content between 10% and 50% for a time in excess of 3 hours, was the most effective treatment. Wood with a moisture content of less than 10% was difficult to disinfect with either gas, whereas wood of a moisture content greater than 50% was somewhat less difficult. Bacteria were more resistant than fungi to sterilization with either gas, and it was indicated that Ascomycetes were more resistant to propylene oxide sterilization than were Basidiomycetes.
Methods of measuring hydrokinetic pressure gradients in the xylem of plants in situ
Authors: Tyree M. T. , Fensom D. S.
Published: August 2008

Three techniques have been proposed for measuring hydrokinetic pressure gradients in the xylem of plants applying the Onsager equations of irreversible thermodynamics. In the first the same electrical gradient is applied in alternate directions in a tree and the resulting current difference ΔI is measured. ΔI is directly proportional to the hydrokinetic pressure gradient, and by this method has been found in Eucalyptus to be about 0.13 atm m−1. Measurements of streaming potential gradients are also a linear function of the hydrokinetic pressure gradient and this has been calculated in maple to be between 0.6 to 1.2 atm m−1. A direct measurement of transpiration flow by tracer methods has also been considered.
Determination of transport constants of isolated Nitella cell walls
Authors: Tyree M. T.
Published: August 2008

Transport coefficients LPP, LPE, LEP, and LEE for electrokinetic equations according to irreversible thermodynamics, the Onsager coefficients, were measured for isolated Nitella flexilis cell walls in KCl solutions ranging from 10−4 to 100 normal. LPP and LPE (= LEP) were found to be independent of KCl concentration and equal to 1.4 × 10−6 cm3 sec−1 cm−2 (joule cm−3)−1 cm and 6 × 10−5 cm3 sec−1 cm−2 volt−1 cm respectively. LEE was a function of the salt concentration, reaching a limiting value of about 1.2 × 10−3 mho cm−1 in 10−4 N KCl. The activation energy for movement of KCl in cell walls was found to be 4.33 Kcal mole−1; the diffusion coefficient for KCl in cell walls was calculated by two methods to be 8 × 10−6 cm2 sec−1; and the concentration of the fixed ions in Nitella cell walls from the above data was estimated at greater than 0.04 equivalent per liter of cell wall. Electroosmosis in Nitella membranes is re-examined in the light of the measured transport coefficients and it is concluded that under proper conditions the cell wall of Nitella can contribute significantly (~20% or more) to the observed electroosmosis of living Nitella cells.
Pollen morphology and chromosome numbers of the family Plantaginaceae in North America
Authors: Bassett I. J. , Crompton C. W.
Published: August 2008

Pollen grains of 28 Plantago and one Littorella species found in North America are described in detail and a key to their identification is presented. The general distribution, habitats, pollen production per anther, flower types (i.e. cleistogamous or chasmogamous) are given for each taxon and in addition the chromosome numbers are reported for 17 Plantago species and Littorella americana. Evidence is presented that Plantago fastigiata does not belong to the section Leucopsyllium. Fossil pollen grains of the Plantaginaceae, most likely to be found in any quantity in postglacial deposits of the Pleistocene epoch, are as follows: Plantago rugelii; P. cordata; P. eriopoda; P. macrocarpa; P. maritima; P. canescens; and Littorella americana.
Bicarbonate ion assimilation in photosynthesis by Sargassum muticum
Authors: Thomas E. Ann , Tregunna E. B.
Published: August 2008

Net inorganic carbon assimilation by Sargassum muticum was recorded in the light up to pH 9.9 and at pCO2 down to less than 5 p.p.m. Carbon uptake was measured on the basis of changes in the CO2 released by acid from 1-ml samples of the experimental seawater, and also calculated from pCO2, and pH according to standard tables. The pCO2 was monitored by infrared gas analysis. It was concluded that this alga assimilated HCO3− ion directly in photosynthesis.
Metabolism of sporulation in filamentous fungi. I. Glucose and acetate oxidation in sporulating and nonsporulating cultures of Endothia parasitica
Authors: McDowell L. L. , Hertogh A. A. De
Published: August 2008

Radiorespirometric patterns for the oxidation of specifically labelled 14C-glucose and 14C-acetate suggest that two dominant pathways operating in Endothia parasitica are the Embden–Meyerhof–Parnas (EMP) and the hexose monophosphate shunt (HMP). Activity of both pathways appears to be stimulated during sporulation, with the HMP being stimulated to the greatest extent. An additional pathway for the oxidation of glucose, presumably the glucuronic acid pathway, appears to be initiated during sporulation. Evidence points to a divergence in the pathway of acetate utilization during sporulation. The nature of this divergence suggests a close relation between sporulation and increased fatty acid and de novo pigment synthesis.
Metabolism of glucose-14C, pyruvate-14C, and mannitol-14C by Melampsora lini. II. Conversion to soluble products
Authors: Mitchell D. , Shaw Michael
Published: August 2008

Mycelium of the flax rust fungus (Melampsora lini (Pers.) Lév.), grown on flax cotyledons in tissue culture, had a mean [Formula: see text]of 4.1 and a mean C6/C1 ratio of 0.14, measured after 4 hours in radioactive glucose. The C6/C1 ratio increased with time and also after treatment with 10−5 M 2,4-dinitrophenol. The relative labelling of the (80%) ethanol-soluble carbohydrates, and organic and amino acid fractions after incubation with glucose-1-, -2-, or -6-14C also indicated preferential release of C1 as 14CO2. Trehalose (unknown A) was tentatively identified in the carbohydrate fraction and was mildly radioactive after incubation of the mycelium with labelled glucose for 3 hours. The principal radioactive products of glucose in this fraction were two unknowns, B and C, which were tentatively identified as mannitol and arabitol. The labelling patterns were consistent with their formation from intermediates of the pentose phosphate pathway. The distribution of radioactivity derived from glucose in alanine, glutamate, and aspartate also indicated that hexose or triose units formed in the pentose phosphate pathway were converted to pyruvate, which either gave rise to alanine or was further oxidized in the tricarboxylic acid cycle. Incubation with pyruvate-1-, -2-, or -3-14C for 3 hours gave rise to 14CO2 and labelled alanine, glutamate, and aspartate in a manner consistent with the operation of the TCA cycle. Mannitol-1-6-14C was not metabolized to any appreciable extent in this period, but did give rise to 14CO2 and to several unidentified compounds in the carbohydrate fraction.
Measurement of inorganic carbon and photosynthesis in seawater by pCO2 and pH analysis
Authors: Tregunna E. B. , Thomas E. Ann
Published: August 2008

An infrared carbon dioxide analyzer was used to measure the pCO2 of air in equilibrium with seawater. From the pCO2 and pH of the seawater, the amount of bicarbonate plus carbonate ion could be calculated. These values were also obtained by acidifying the seawater and measuring the amount of carbon dioxide that was released. These methods provide accurate measurements of the concentrations of inorganic carbon which are available for photosynthesis by marine plants. For example, these techniques showed that Iridaea cordatum used bicarbonate ion rather than CO2 during photosynthesis at high pH.
Conidium ontogeny in hyphomycetes. Gonatobotryum apiculatum and its botryose blastospores
Authors: Kendrick W. B. , Cole G. T. , Bhatt G. C.
Published: August 2008

Gonatobotryum apiculatum (Peck) Hughes is described from pure culture for the first time, and compared with previous collections on Hamamelis virginiana and Liquidambar styraciflua. The ontogeny of its botryose blastospores is illustrated by time-lapse photomicrography.
A technique for the study of floral development
Authors: Sattler Rolf
Published: August 2008

When floral buds are studied by serial sectioning, the obtained three-dimensional picture of the buds is a reconstruction which involves some theoretical elements. In contrast to this reconstructive method, the described technique permits the direct study of the three-dimensional developmental stages of flowers. Protoderm cells of floral apices and primordial appendages can be demonstrated.
L'évolution nucléaire dans l'asque du Didymella applanata
Authors: Julien J. Bernard
Published: August 2008

not available
Some geographic variations in Picea sitchensis and their ecologic interpretation
Authors: Daubenmire R.
Published: August 2008

Mass collections of Picea sitchensis, and hybrids, extending from Haines, Alaska, to northern California have been studied with respect to morphology of the ovuliferous cones, twigs, and needles. The Pleistocene history of the species has been reviewed. A north–south gradient occurs in size of cone, length–width ratios of cone scales, sterigma angle, and phyllotaxy. The gradient is probably clinal and appears unaffected by the northerly three-fourths of the species range being in glaciated territory where Pleistocene survival, on nunataks, is suggested by the data. Collections along two sections of the Skeena River in British Columbia are interpreted as hybrid P. sitchensis × P. glauca populations backcrossed with the nearest one of the two parents, i.e., with P. sitchensis near the coast and P. glauca farther inland. Insular populations tend to show less variability in length–width ratios of the ovuliferous scales than do mainland populations.
Nuclear phenomena in the ascospores of Hypoxylon punctulatum
Authors: Rogers Jack D.
Published: August 2008

The ascospores of Hypoxylon punctulatum are uninucleate when formed, becoming multinucleate as they mature. It is the first Hypoxylon species to show regularly multinucleate ascospores. The chromosome number apparently is n = 4.
Nitrogen metabolism of Picea glauca. I. Seasonal changes of free amino acids in buds, shoot apices, and leaves, and the metabolism of uniformly labelled 14C-L-arginine by buds during the onset of dormancy
Authors: Durzan D. J.
Published: August 2008

Buds, shoot apices, and leaves from terminal shoots of white spruce saplings accumulated high levels of alcohol-soluble nitrogen in spring, late summer, and early winter. Major components, e.g. arginine, glutamine and proline, of the soluble nitrogen showed patterns complementary to each other. These changes represented the storage and mobilization of nitrogenous compounds during the onset of dormancy or the growth of shoots. Leaves contained less total soluble nitrogen than buds or shoot apices. Soluble nitrogen and arginine content of leaves resembled buds in their seasonal patterns but changes in aspartic acid, glutamic acid, and alanine were much greater than in buds, especially in late summer.When the first frost appeared, uniformly labelled 14C-arginine, applied to the apices of buds, readily entered newly synthesized protein, and free arginine was converted to proline via ornithine. Proline with carbon derived from arginine also entered proteins that were metabolized at different rates. A fraction of the proline in protein was hydroxylated to hydroxyproline. Although traces of 14C-citrulline were detected, more carbon was metabolized to free guanidino compounds, e.g. α-keto-δ-guanidinovaleric acid, γ-guanidinobutyric acid, and several monosubstituted guanidines. After 24 hours, labelled arginine, proline, and γ-guanidinobutyric acid moved down the shoot to the leaves. These metabolic changes in buds show that many of the seasonal changes in amino acids are intimately related to the carbon and nitrogen metabolism of arginine.
Nitrogen metabolism of Picea glauca. III. Diurnal changes of amino acids, amides, protein, and chlorophyll in leaves of expanding buds
Authors: Durzan D. J.
Published: August 2008

In spring, buds of spruce shoots under moisture stress contracted during the day and expanded at night. Increased water supply to roots removed the shrinkage of buds and stimulated rapid expansion. In leaves of buds about to break and under moisture stress, the alcohol-soluble nitrogen, high in arginine content, was maximal at midday, after midnight, and again at noon the next day. As a percentage of the soluble nitrogen, all compounds, except arginine, contributed most at sunset and again at sunrise. Other prominent amino acids included proline, alanine, γ-aminobutyric acid, and the amides glutamine and asparagine. Except for the amides, these and other compounds, present at lower levels, gave diurnal patterns similar on a fresh weight basis to arginine. Values for protein nitrogen were greatest at 2 p.m. followed by an increase of asparagine nitrogen, and again at 4 a.m., followed by an increase of glutamine nitrogen. At night the composition of newly synthesized protein increased significantly in aspartic acid, serine, glycine, alanine, leucine, and isoleucine. Chlorophyll a increased from 2 p.m. to 10 p.m., whereas chlorophyll b was present at lower levels and showed little diurnal variation.
The measurement of cell density in suspension cultures using dichromate oxidation
Authors: Miller R. A. , Wilkinson A. , Kirkpatrick J. W.
Published: August 2008

A rapid procedure for the determination of organic matter in suspension cultures is reported using dichromate oxidation and special apparatus; the method is suitable for routine determinations. Accurate results may be obtained in 30 min and the useful range is about 0.26 to 2.6 mg cells/ml.
Strigopodia
Authors: Hughes S. J.
Published: August 2008

Two species of Pyrenomycetes associated with resinous exudates of conifers are illustrated and described in the genus Strigopodia Bat.; the phragmoconidial and phialidic states are recognized as belonging to the form genera Hormisciella Bat. and Capnophialophora Hughes respectively.The type species of Strigopodia, S. piceae Bat., is included as S. resinae (Sacc. & Bres.) n. comb., syn. Capnodium resinae Sacc. & Bres. In its mycelial state it was described as Racodium resinae Fr. β piceum Pers. Its phragmoconidial state is identified with Helminthosporium resinaceum M. C. Cooke, syn. H. resinae Bres., and Clasterosporium resinae Rilstone. This species occurs in Eastern United States of America (Maine, New Hampshire) and in Europe.A new species S. batistae is recorded from Western United States of America (Calif., Wash., Idaho) and Western Canada (B.C.), and its phragmoconidial state is identified with Helminthosporium pseudotsugae W. B. Cooke.The affinities of Strigopodia are with the capnodiaceous fungi rather than with the Parodiopsidaceae.
Some observations on chromatin fibers of isolated pea nuclei
Authors: Yoo B. Y.
Published: August 2008

Nuclei were isolated from apical portions of 5- to 7-day-old pea seedlings, and chromatin fibers were studied in sections of intact nuclei after the sections were fixed in glutaraldehyde followed by OsO4. For study of whole mounts, isolated nuclei were ruptured by two methods: repeated freezing and thawing; washing nuclei with distilled water on the grids. Whole mounts of ruptured nuclei were negatively stained with phosphotungstic acid. Chromatin fibers prepared in this way had diameters of 35 Å to 100 Å, while the diameters of the fibers in thin sections fell in the range of 100 Å – 140 Å.In some distilled-water-ruptured preparations, the chromatin fibers resembled a beaded string, and the material composing the beads was extractable with 2 M NaCl. As a result of salt extraction, a fine fibrillar core became evident and was stained in uranyl acetate. The diameter of the core was about 20 Å – 35 Å.Variations in the diameter and granular appearance of negatively stained fibers seemed to be primarily caused by uneven distribution and local accumulation of the "sheath" material. A chromatin fiber appears to be constituted of a single central deoxyribonucleic acid (DNA) core of about 20 Å to 35 Å, surrounded by sheath material.
Cryptophiale, a new genus of Hyphomycetes
Authors: Pirozynski K. A.
Published: August 2008

Cryptophiale, a new genus of phialidic dematiaceous Hyphomycetes is described to accommodate two new species occurring in leaf litter: C. kakombensis Pirozynski from Tanzania, and C. udagawae Pirozynski & Ichinoe from Japan.
Translocation of radioactive sugars in vascular tissues of soybean plants
Authors: Trip P. , Gorham P. R.
Published: August 2008

Radioactive sugars were introduced in soybean plants either through the stump of a cut petiole or through a flap formed by a cut lateral vein of a leaf. After 5 to 180 minutes the location, distribution, and nature of the tracer was determined. When sucrose, glucose, and mannitol were introduced via a cut petiole, they were translocated in the stem via the xylem and they passed through a steam girdle contrary to results previously reported in which sucrose transport appeared to be blocked. When labelled glucose was introduced via a lateral leaf vein it was metabolized and translocated as sucrose from the leaf via the phloem in a manner closely resembling that of photosynthate.
Wall development within the microspore tetrad of Lilium longiflorum
Authors: Heslop-Harrison J.
Published: August 2008

Characteristics of the spore walls developing during the tetrad period have been studied in Lilium longiflorum using cytochemical methods and scanning electron microscopy. Following upon meiosis II, each spore forms a separate wall, the primexine. The primexine consists of a tenuous matrix component identified tentatively as cellulose, traversed by radially directed rods, the probacula. Initially these possess a lamellated or granular appearance, and are not resistant to acetolysis; their chemical identity at this early developmental stage is unknown. The distribution of the probacula and the interconnections they form above and below the loose matrix material establish the basis of the final exine pattern. As the tetrad ages, the patterned component formed by the probacula becomes resistant to acetolysis. On release from the tetrad, the spores expand, and there is a rapid accretion of new materials in the patterned wall component. For a period, free aldehyde groups appear in the wall, but this characteristic is lost in the mature exine. The cellulose matrix of the primexine is dispersed and probably partly degraded after release of spores from the tetrad, but a residue persists in the exine cavities.
Fructosan in the timothy haplocorm
Authors: Suzuki Michio
Published: August 2008

A fructosan fraction which made up 63% of the water-soluble carbohydrates of the timothy haplocorm was shown to be composed of a series of polyfructoses with different chain lengths. An 80% ethanol extract from fresh timothy haplocorm contained long-chain fructosan in addition to short-chain fructosan, sucrose, glucose, and fructose. Most of the long-chain fructosan was found in the water extract from residue obtained after the 80% ethanol extraction. This fructosan fraction was extracted directly with water and separated from other botanical components by gel filtration. The compound was readily hydrolyzed in a 0.01 N HCl solution producing fructose accompanied with small amounts of sucrose and glucose. The molecular weight of fructosan as estimated by a gel filtration using a G-75 Sephadex column was 12 700–14 300, being equivalent to 78–88 degrees of polymerization (D.P.). The infrared spectrophotometric measurements of fructosan showed absorbances at 933, 905, 872, 844, and 813 cm−1 for the phlein type obtained from the timothy haplocorm, while the inulin-type fructosan from chicory showed characteristic bands at 933, 872, and 813 cm−1.
Morphophysiological studies of the shoot apex. I. Recurrent growth flushes and their relationship with structural changes in the growing apex of Callistemon viminalis
Authors: Purohit A. N. , Nanda K. K.
Published: August 2008

The annual growth cycle of Callistemon viminalis consists of three phases: (1) a reproductive phase that continues till the end of February; (2) a vegetative phase that lasts from the end of February till the end of August; and (3) a long dormant phase which lasts till the end of December. The cycle exhibits four growth flushes with alternating periods of active growth and rest. The duration of the successive rest periods increases, leading eventually to the onset of the long dormant phase.The growing apex exhibits more or less similar histological changes in different growth flushes. An increase in divisional activity of the cells of flanking meristem, accompanied by a decline in the elongation of cells of pith rib meristem, characterizes the rest period. During the active period of growth, the cells of the pith rib meristem elongate but the activity of the flanking meristem decreases. The number of leaves produced in each growth flush, therefore, is dependent upon the duration of the preceding rest period, and their size and nature on the duration of active growth. In growth flush 1 the cells of the rib meristem show elongation twice during the active period corresponding with the separation of floral buds and of foliage leaves respectively. In the long dormant phase, on the other hand, the cells of the flanking meristem show high divisional activity twice, first during September when new leaf primordia are initiated, and again during November when floral buds are initiated. Events of great significance thus occur during the long dormant phase. The reproductive development is characterized by a marked increase in the rate of cell division in the flanking meristem accompanied by cessation of growth, the features that characterize the rest period as well.
The genus Atriplex (Chenopodiaceae) in Canada. I. Three introduced species: A. heterosperma, A. oblongifolia, and A. hortensis
Authors: Frankton C. , Bassett I. J.
Published: August 2008

Descriptions, illustrations, and distribution data are given for three introduced species of Chenopodiaceae: Atriplex heterosperma Bunge, A. oblongifolia Waldst. et Kit., and A. hortensis L. Atriplex heterosperma and A. oblongifolia are new to Canada and have not been dealt with in any North American flora.
Draba norvegica, disjunct to the Mackenzie District, Northwest Territories, Canada
Authors: Mulligan Gerald A. , Cody William J.
Published: August 2008

A population of the amphiatlantic species Draba norvegica Gunn. was found in the Mackenzie District, Northwest Territories, nearly a thousand miles west of the nearest plants of this species in northeastern North America. Mackenzie District plants have the chromosome number n = 24.
Taxonomic study of Pyronemella monilifera
Authors: Tewari V. P. , Pant D. C.
Published: August 2008

Pyronemella monilifera collected from Dronagiri hills (alt. 7000 ft), Almora, India, has been described and illustrated. Comparison of the Indian material with the type specimens of Peziza monilifera and Peziza sphaeroplea has shown that the three collections form an intergrading series with overlapping characters. All three collections are therefore considered to belong to Pyronemella monilifera.
Studies of hypodermataceous needle diseases. I. Isthmiella quadrispora sp. nov., causing needle blight of alpine fir
Authors: Ziller Wolf G.
Published: August 2008

A new parasite causing needle disease of alpine fir (Abies lasiocarpa (Hook.) Nutt.) in western Canada and named Isthmiella quadrispora sp. nov. is illustrated and described. It resembles I. faullii (Darker) Darker in morphology, pathogenicity, life cycle, host range, and associated fungi; but differs from I. faullii in its apparent lack of an imperfect state, the subcuticular position of its ascomata, its stipitate, narrow, four-spored asci, and the germination of its spores. Field observations indicate a 2-year life cycle and great differences in susceptibility of individual host trees. Several secondary associated fungi prevent spore formation of I. quadrispora, thus acting as biologic control agents.
Carpospore germination and the life history of Cumagloia andersonii: some observations from culture
Authors: South G. Robin
Published: August 2008

The germination and development in culture of carpospores of Cumagloia andersonii (order Nemalionales, family Helminthocladiaceae) are described. Spores develop into a prostrate filament from which arises a branched upright system showing the basic construction of the multiaxial gametophyte plant; the cultured plants, however, lack the organization and normal external morphology of the gametophytes from the field, and are devoid of reproductive organs. Present studies indicate development of the gametophyte from carpospores with an intermediate prostrate stage; cytological and further culture studies are needed to describe the life history.
Eight species of Mancicorpus from the Edmonton Formation (Maestrichtian), Alberta, Canada
Authors: Srivastava Satish K.
Published: August 2008

Eight species belonging to the genus Mancicorpus are reported from the Edmonton Formation (Maestrichtian) of Alberta, Canada. Five new species are formally described and their holotypes designated.
Enhancement of brown rust in three varieties of wheat by Mendok treatment
Authors: Rustagi P. N. , Ram H. Y. Mohan
Published: August 2008

In a study intended to evaluate the gametocidal effect of Mendok (sodium 2,3-dichloroisobutyrate) applied to the foliage of four varieties of wheat, varying degrees of intensity of brown rust infection and sporulation were observed. The varieties resistant to brown rust (Lerma Rojo and Sonora 64) became less resistant, while the susceptible variety (N.P. 718) showed moderate to heavy infection in contrast to the unsprayed controls. The enhancement of rust incidence was associated with the growth responses produced by the chemical. Application of Mendok may thus be useful for maintaining rust cultures and for multiplying the inoculum.
A modified Denny osmometer for permeability studies with plant membranes
Authors: Dumbroff E. B. , Webb D. P.
Published: August 2008

An osmometer that can provide a direct estimate of permeability of various plant membranes under standardized conditions is described and potential applications suggested.
Altering Avalonia: oxygen isotopes and terrane distinction in the Appalachian peri-Gondwanan realmLaboratory for Stable Isotope Science (LSIS), The University of Western Ontario, Contribution 236.
Authors: Potter Joanna , Longstaffe Frederick J. , Barr Sandra M. , Thompson Margaret D. , White Chris E.
Published: August 2008

Distinct 18O depletion is characteristic of a large majority of the 620–550 Ma felsic igneous rocks of Avalonia in the northern Appalachian orogen. Neoproterozoic rocks in the Boston Avalon terrane have the lowest δ18OWR values (≥–3.1‰), followed by the Mira terrane in Cape Breton Island and the Caledonia terrane in New Brunswick (≥–1.2‰), the Avalon terrane in Newfoundland (≥+2.8‰), and the Antigonish Highlands in Nova Scotia (≥+5.3‰). In contrast, this depletion of 18O is observed in very few of the Paleozoic felsic igneous rocks from these Avalonian terranes, and also in very few of the Neoproterozoic and Paleozoic felsic igneous rocks from the inboard Ganderian terranes. The low-18O character of the Neoproterozoic igneous rocks is related to regional pervasive, post-magmatic alteration by predominantly meteoric-hydrothermal fluids (δ18OH2O ∼–6‰ to –4‰) at 200–450 °C. The alteration likely occurred during late Neoproterozoic transtensional extension of Avalonia. Large-scale fluid infiltration and circulation within the Avalonian crust accompanied this extension with development of pull-apart sedimentary basins and extension-related magmatism that were the prelude to Cambrian submergence of Avalonia. This regional 18O depletion provides a geochemical fingerprint by which Avalonia can be distinguished from other peri-Gondwanan terranes. These data suggest that Avalonia existed as a composite terrane on the Gondwanan margin in the Neoproterozoic, separate from Ganderia.
Average Age at First Reproduction of the Northern Fur Seal (Callorhinus ursinus)
Authors: York Anne E.
Published: August 2008

Three methods of estimating average age at first reproduction of the northern fur seal, Callorhinus ursinus, are presented. For the first, the percentage of females pregnant for the first time is estimated from the percentage of primiparous pregnant females in the population. For the second, the percentage of females pregnant for the first time is estimated from the difference in the percentages of females pregnant at least once at successive ages. The jackknife variances of both estimates are presented. The estimates are calculated for the 1954–64 year-classes of northern fur seals using data collected at sea by the United States and Canada during 1958–74. By fitting parametric curves to the fraction pregnant at least once as a function of age and applying the second method to that resulting curve, the average age at first reproduction is estimated in a third way; this method is applicable to year-classes for which data are incomplete and estimates are given for the 1952, 1953, 1965, and 1966 year-classes. Age at first reproduction was lowest for the 1952–55 year-classes, increased sharply beginning with the 1956 year-class, and then gradually decreased almost to the level of the 1952–55 year-classes. Average age at first reproduction is negatively correlated with juvenile survival (birth to age 2 yr).Key words: fur seal, northern fur seal, Callorhinus ursinus; average age at first reproduction, cohort analysis, population dynamics
Chemical and Radiotracer Measurements of Phosphorus Uptake by Lake Plankton
Authors: Lean D. R. S. , White E.
Published: August 2008

Either chemical or radioisotope methods can be used to measure the maximum uptake velocity for phosphorus in lake water but neither can measure uptake at ambient concentrations. Chemical estimates at ambient concentrations are insensitive and the isotope method provides the uptake rate constant only. By multiplying the uptake rate constant by the ambient phosphate concentration one obtains an estimate for phosphorus influx, but reliable estimates for ambient phosphate concentrations are still unattainable. At added phosphate levels even up to 10 μg P∙L−1, the isotope method overestimates net phosphate uptake because of release of phosphate from the plankton. Influx and efflux are practically equal under steady state conditions, and during periods of phosphate limitation a net uptake of phosphorus occurs only when there is an increase in the phosphorus supply. The uptake of phosphate is predominantly by small cells at low concentrations of added phosphate and by larger cells at the higher enrichments. This makes the use of the radiobioassay for estimating ambient phosphate concentrations difficult to interpret. Furthermore the half-saturation coefficients measured for whole lake water are a mean for the entire population and consist of small values for small algae and bacteria and larger values for larger algae.Key words: phosphorus, kinetics, plankton, algae, bacteria nutrition
Stress Response and Blood Characteristics of Channel Catfish (Ictalurus punctatus) after Anesthesia with Etomidate
Authors: Limsuwan Chalor , Limsuwan Tasanee , Grizzle John M. , Plumb John A.
Published: August 2008

Continuous anesthesia of channel catfish (Ictalurus punctatus) with 0.6 mg/L etomidate for 96 h caused a small but statistically significant decrease in plasma protein concentration at all sampling periods. Hemoconcentration, indicated by increased total erythrocyte count, hematocrit, and hemoglobin, resulted from anesthesia with 1–4 mg/L etomidate for 30–180 min. Periodic removal of fish from 400-L troughs stressed other unanesthetized fish in the trough causing significantly increased plasma corticosteroid, glucose, and protein concentrations. Anesthetized fish were not stressed by the periodic sampling. Fish anesthetized with 3 mg/L etomidate and then confined in a net for 10 min had reduced plasma Cortisol response and no significant plasma glucose increase compared with unanesthetized controls. Anesthesia did not prevent hyperchloremia that developed 3 h after the 10-min confinement. No histological changes were found in fish anesthetized with etomidate. Anesthesia with etomidate before netting could be useful when handling fish because of the reduced stress response.
A Time Series Approach to Forecasting Angling Activity at a Recreational Site Based on Past Successes
Authors: Steinnes Donald N. , Raab Raymond L.
Published: August 2008

A multiple regression model was developed for estimating or forecasting the impact of past fishing "successes" on the current angling activity or participation at a recreational site. Through this approach we demonstrate the usefulness of time series methodology as a forecasting tool by investigating the lag structure of success and measuring its elasticity. We evaluated empirical results, based on daily time series data for a Lake Superior river; these indicate that anglers respond more to past total success at the site than to past success per unit of effort at the site. Finally, we examined how the model could be extended so as to estimate the economic value of catching a fish and how, in turn, such an extended model might be part of a comprehensive approach for valuing changes in habitat using benefit-cost analysis.
Counterimmunoelectrophoresis for Identification of Infectious Pancreatic Necrosis Virus After Isolation in Cell Culture
Authors: Dea S. , Elazhary M. A. S. Y.
Published: August 2008

An isolate of IPNV identified by seroneutralization test as serotype VR-299 was produced in RTG-2 cells, purified by density gradient centrifugation, and used to prepare the immune serum. Parameters of the CIE technique were adapted for the IPNV and one precipitin line was observed either with the purified antigen or with known positive specimens. A greater number of fish organ homogenates were positive after multiple passages in cell cultures than by direct CIE examination. However, the precipitin antigen was detected in cell culture fluid at early passages. The use of CIE following virus isolation in cell culture is recommended for routine identification of IPNV.
A Model of Feeding by Parasitic Lampreys
Authors: Cochran Philip A. , Kitchell James F.
Published: August 2008

We derived a quantitative feeding model to estimate energy intake by parasitic sea lampreys (Petromyzon marinus) as a function of lamprey mass, host mass, and attachment time. Comparison of model predictions with observed growth by lampreys with known feeding histories suggests that the feeding model, used in conjunction with a previous model of lamprey energetics, generates unbiased predictions of energy intake and subsequent growth. On the basis of the relationship between energy intake and attachment time, and in accordance with previous theory on partial prey consumption, we hypothesized that duration of attachment by lampreys to individual hosts should vary inversely with host density. No significant difference in attachment time or latency to attack at two host densities could be detected, although the first attachment by a lamprey tended to be longer than its second, regardless of host density.
Changes in Conductivity, Alkalinity, Calcium, and pH During a 50-Year Period in Selected Northern Wisconsin Lakes
Authors: Eilers J. M. , Glass G. E. , Pollack A. K. , Sorensen J. A.
Published: August 2008

Between 1925 and 1941, E. A. Birge, C. Juday, and co-workers in Wisconsin made extensive water quality measurements on over 600 northern Wisconsin lakes, providing a benchmark against which comparisons can be made if the modern equivalent measurements can be determined. Of these, 149 lakes were sampled from 1979 to 1983. Data on conductivity, alkalinity, calcium, and hydrogen ion (pH) are available for these lakes from 1925 to 1931. The historical methyl orange alkalinity data were adjusted to be comparable to the recent Gran alkalinity data by subtracting 57 μmol/L from the historical measurements. The colorimetric historical pH measurements were adjusted to be comparable to recent potentiometric measurements by a regression model. No adjustments were made to the historical calcium or conductivity measurements. Comparisons of adjusted historical data with recent data show a significant increase in the means of all four variables. The largest increases in all four variables show an association with increases in land use development on the lake perimeters. Statistically significant changes in alkalinity are observed, with 28 lakes increasing and 11 decreasing, compared with 110 lakes showing no change. Possible explanations for chemical changes in those lakes that have experienced little change in land use are discussed. For the lakes in northern Wisconsin which may have been affected by airborne pollutants, it is likely that these effects had their beginning before initiation of the historical lake survey.
The Monotypic Sardines, Sardina and Sardinops: Their Taxonomy, Distribution, Stock Structure, and Zoogeography
Authors: Parrish R. H. , Serra R. , Grant W. S.
Published: August 2008

This paper reviews the taxonomy, distribution, stock structure, biochemical genetics and zoogeography of the world's two subtropical sardines, Sardina and Sardinops. We conclude that both genera are monotypic and that the differences between populations of Sardinops in different current systems are not large enough to consider them distinct subspecies. Analysis of biochemical genetics information, fossil evidence, and present and paleo-climatic conditions suggests that Sardinops did not achieve its present distribution until the Pleistocene and that westward exchange of sardines via the northern and southern west wind drift regions is possible with present climatic conditions. Transequator exchange appears to be possible only during glacial maxima and only in the eastern tropical Pacific.