bluuebunny/crossref_metadata_2025 huggingface dataset:
The rhizoids of Polysiphonia lanosa
Authors: Rawlence D. J. , Taylor A. R. A.
Published: September 2008

Polysiphonia lanosa (L.) Tandy, a red alga (family Rhodomelaceae) epiphytic upon Ascophyllum nodosum (L.) Le Jolis and occasionally upon species of Fucus L., has been shown to have both a primary sporeling rhizoid and secondary rhizoids that may arise from either pericentral or central cells. Rhizoids were examined live after dissection from the host tissue. Considerable variation was found in rhizoid form and structure. Many rhizoids become complex by the penetration of additional rhizoid-like extensions from other pericentral or central cells into the originally simple rhizoid. In a small proportion of rhizoids examined, a protoplasmic protrusion was found to extend through the rhizoid wall near the apex, but there was no evidence that this formed any haustorial connection with A. nodosum cells. Excised fragments of P. lanosa cultured in close association with pieces of A. nodosum reestablished superficial contact with the A. nodosum plants by growth of new secondary rhizoids, but these did not penetrate the host tissue.
The relict occurrence of Seligeria pusilla in Arctic Canada
Authors: Brassard Guy R.
Published: September 2008

Seligeria pusilla has been found on northern Ellesmere Island, Arctic Canada. This disjunct occurrence, along with a similar one in Arctic Alaska, indicate that the species is a glacial relict. The moss is described and illustrated from arctic material, and important differences between arctic and temperate specimens of S. pusilla are enumerated.
Investigations of the marine algae of Nova Scotia. VIII. The flora of Digby Neck Peninsula, Bay of Fundy
Authors: Edelstein T. , Chen L. , McLachlan J.
Published: September 2008

The algal flora at two selected sites on the Digby Neck Peninsula, Bay of Fundy, was examined at monthly intervals for a year. One hundred and eighty-seven species and varieties were recorded; of these 76 are newly recorded for the Bay of Fundy and 11 are new records for North America. A taxonomic listing, inclusive of reproductive structures found during the year, is given. Seasonal changes and vertical migration of the algae are discussed.
Studies on the mechanism of action of β-methylaspartic acid in the suppression of Aphanomyces root rot of pea
Authors: Lumsden R. D. , Papavizas G. C. , Ayers W. A.
Published: September 2008

β-Methylaspartic acid (MAA) effectively reduced root rot of pea, caused by Aphanomyces euteiches, at concentrations as low as 4 p.p.m., and prevented disease at 15–20 p.p.m. The degree of methylation of pectic materials in healthy pea plants was not increased by MAA, which thus could not account for induced resistance to root rot. Further studies revealed that MAA in the absence of glutamic acid affected zoospore germination and inhibited growth of A. euteiches in vitro. Inhibition of growth and of root rot development was almost completely reversed by glutamic and aspartic acids, and partly reversed by several other amino acids. Studies of the mechanism of inhibition of growth of A. euteiches by MAA indicated that MAA did not affect glutamine synthetase or aspartate oxoglutarate transaminase, two amino acid metabolizing enzymes produced by A. euteiches, nor did it affect the uptake of 14C-labeled glutamic acid by mycelium of the fungus and the incorporation of glutamate into alcohol-insoluble material. It was concluded that MAA directly affects growth of A. euteiches and in this way controls root rot of pea.
Comparison of extracellular polysaccharide of Xanthomonas campestris from culture and from infected cabbage leaves
Authors: Sutton John C. , Williams Paul H.
Published: September 2008

The extracellular polysaccharide fraction of Xanthomonas campestris was precipitated with hexadecyltrimethylammonium bromide from aqueous extracts of cabbage leaves infected with the black rot pathogen, and further purified by repeated precipitation with ethanol. The polysaccharide fraction was shown to be similar to extracellular polysaccharide fraction purified from culture fitlrates of X. campestris. Sugars present in samples of acid-hydrolyzed polysaccharide were identified by gas–liquid chromatography. Chromatograms showed that polysaccharide purified from infected cabbage leaves contained glucose, mannose, and glucuronolactone in ratios similar to those of the polysaccharide from culture filtrates. Polysaccharide purified from noninfected cabbage leaves contained only glucose and galactose. The polysaccharide from infected cabbage leaves was serologically related to polysaccharide from culture filtrates. In immunodiffusion tests both the polysaccharide fractions from culture filtrates and that from infected leaves reacted to give two precipitin bands with an antiserum to the polysaccharide from culture filtrates. No precipitin bands formed with polysaccharide from noninfected leaves. Antibodies against the culture polysaccharide were completely removed from the antiserum by the polysaccharides isolated from infected cabbage leaves. A weakly virulent isolate of X. campestris did not produce extracellular polysaccharide in culture filtrates.
Axenic culture of myxamoebae of the myxomycete Echinostelium minutum
Authors: Haskins Edward F.
Published: September 2008

Axenic cultivation of the myxomycete Echinostelium minutum De Bary (Echinosteliales) is reported for the first time. After more than a year of serial passage the average generation time of amoebae during the logarithmic phase is 18 h and a stationary phase yield of over 2 × 106 cells/ml is typical.
Primary productivity and standing crops of phytoplankton in Belwood Reservoir
Authors: Duthie Hamish C. , Kirton Jr. William L.
Published: September 2008

In experiments conducted simultaneously at two stations in Belwood Reservoir it was found that while the standing crop and the rate of assimilation per square meter were less at a station just below the inflow, the activity coefficient was generally higher than at a station near the dam. The activity coefficient varied from 0.19 with a population consisting mainly of Cryptomonas, Asterionella, and Dinobryon to 0.02 with a very large population of mainly Ceratium hirundinella. In general there was an inverse relationship between standing crop and activity coefficient. Daily production estimates ranged from 134 mg C/day m2 to 1650 mg C/day m2. A population of Peridinium aciculiferum was found to have an activity coefficient of 0.05.
Changes in nitrogen metabolism in the wheat root tip following growth and vernalization
Authors: Ste-Marie Geneviève , Weinberger Pearl
Published: September 2008

Sequential changes in the alcohol-soluble amino acid fraction of vernalized and control root tips of Triticum aestivum var. Marquis (spring) and Rideau (winter) wheats have been followed. Substantial changes in this fraction could be related to developmental changes in the root tip, with protein synthesis occurring most rapidly in the region of elongation. Vernalization superimposed additional, consistent changes mainly in the content of asparagine, glutamine, glycine, and glutamic acid. Incorporation studies using 14C-glutamic acid and aspartic acid served to emphasize the distinct metabolic differences between the mitotic and elongating regions of the root tips. The activity of glutamic acid – alanine transaminase was also studied.
Early responses of sapwood of Quercus bicolor to mechanical injury
Authors: Wardell J. F. , Hart J. H.
Published: September 2008

The response of sapwood of swamp white oak (Quercus bicolor Willd.) to mechanical injury was studied over a 28-day period. In cells within 0.5 cm of a wound stimulus, starch grains disappeared and cells were unable to reduce the vital stain, triphenyl tetrazolium chloride (TTC), 8 to 10 days after mechanical injury. Extraneous material and tannins began to accumulate 10 to 12 days after mechanical injury. Nuclei began to disintegrate 12 to 14 days after mechanical injury, but some persisted throughout the period of investigation.With increasing distance from the cambium, starch grains disappeared from ray parenchyma. Cells in the annual rings of sapwood adjacent to the heartwood were unable to reduce TTC. Nuclei were present in all annual rings of sapwood but were lacking in heartwood. Tannins appeared at the heartwood boundary and accumulated in the heartwood.With respect to the criteria used, this investigation indicates that formation of discoloration in sapwood and conversion of sapwood to heartwood appear similar.
The effect of inoculum concentration on the apparent resistance of muskmelons to Fusarium oxysporum f. sp. melonis
Authors: Douglas Dexter R.
Published: September 2008

The apparent resistance of muskmelons to wilt caused by Fusarium oxysporum f. sp. melonis was dependent on amount of inoculum, in both autoclaved and nonautoclaved soil. Wilt severity, as measured by the number of surviving plants in soil in the greenhouse, varied linearly with decreasing log inoculum concentrations. This relationship of wilt severity to log inoculum concentrations generally held true only over an intermediate range of inoculum concentrations, above which the plants were severely wilted and below which they survived. This was true of the two varieties, 'Pride of Wisconsin' and 'Iroquois', as well as six breeding lines. Tests for selection of lines resistant to wilt caused by this fungus probably should avoid excessive amounts of inoculum, and be made in nonautoclaved soil.
Nitrogen requirements of the genus Linderina
Authors: Stephen R. C. , Chan Christina
Published: September 2008

The influence of different nitrogen sources on the growth of Linderina was examined in liquid culture. Both species of Linderina were unable to assimilate nitrate nitrogen and nitrite seemed to be toxic. Ammonium nitrogen was used but the growth response was considerably lower than that with some organic nitrogen materials. Inclusion in the growth medium of succinic acid as a carbon source failed to improve the assimilation of ammonium.Amino nitrogen as aspartic acid and asparagine gave good growth though not as good as with L- or DL-glutamic acid. The response to DL-glutamic acid was markedly better than to the L-isomer whereas the D-isomer gave relatively poor growth.
Electrophoretic separation of proteins from roots and root exudates
Authors: Juo Pei-Show , Stotzky G.
Published: September 2008

The total protein concentration of exudates released from sterile intact roots of various species (e.g., corn, pea, sunflower) fluctuated markedly during plant development. One major, sometimes with two or three minor, fast-moving soluble protein bands (globulin and albumin) and one weak basic protein band were detected by disc electrophoresis at various developmental stages, whereas 12 to 14 soluble protein bands were detected in seedling roots and at least 16 were distinguished in mature roots. Only one basic protein band was detected in root homogenates and exudates. When individual exudate samples collected at about weekly intervals for 85 days were combined before analysis, 9 to 14 bands were detected, indicating that many, but not all, of the proteins present in roots were liberated, but, with the exception of one or two components, in quantities too low for detection. Comparison of exudates from plants grown in sand or liquid culture indicated that release of proteins did not result from injury of the roots by the sand particles.
Some biological effects of volatiles emanating from wood
Authors: Rice P. F.
Published: September 2008

Early in vitro observations on the biological activity of volatiles from heat-dried woods indicated two major properties: one of retarding growth of higher plants and another of stimulating growth of a wood-inhabiting Basidiomycete. For the purpose of determining the chemical nature of the active volatiles and their parent sources principally in red pine wood (Pinus resinosa), these two properties were investigated separately with the aid of bioassay techniques. Two test organisms were used: germinated kidney beans (Phaseolus vulgaris) and the fungus Fomes annosus. Various dose levels of volatile sources were suspended over the test organisms for a fixed period of time, after which growth was measured.Experimental evidence indicated that bean growth inhibition and fungus growth stimulation could be attributed to volatile autoxidation products derived from certain unsaturated fatty components of wood. In particular, linoleic acid appeared to be a major phytoactive source. A number of aliphatic aldehydes, reported in the literature as fat autoxidation products, were found to be phytotoxic to beans in appropriate quantities, but none had any growth promoting properties on the fungus. Also, indications were that fungus response to wood volatiles was largely independent of the nutrient status of the substrate, provided a suitable nutrient complement was present. It was proposed that yet unidentified non-aldehydic substances, or specific untested aldehydes, functioned as the growth factors.
The effect of heartwood fungi of Pinus contorta var. latifolia on pinosylvin, pinosylvinmonomethyl ether, pinobanksin, and pinocembrin
Authors: Loman A. A.
Published: September 2008

The heartwood of lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) contains considerable amounts of fungitoxic phenolics, but also possesses an extensive fungus flora. Two of the most frequently isolated fungi, Peniophora pseudo-pini Weres. & Gibson and Tympanis hypopodia Nyl., effected the most rapid decrease in concentration of pinosylvin, pinosylvinmonomethyl ether, pinocembrin, and pinobanksin in lodgepole pine heartwood meal. Three mechanisms for the removal of pinosylvin were observed. The laccase-producing ascomycetes, Coryne sarcoides (Dicks. ex Fr.) Bon. and T. hypopodia, caused a decrease in optical density as well as a maximum absorption shift of pinosylvin from 310 mμ to 300 mμ. This shift could be related to the appearance of a new compound which absorbed at 300 mμ. Three laccase-producing basidiomycetes, P. pseudo-pini, Stereum sanguinolentum Alb. & Schw. ex Fr., and Fomes pini (Thore ex Fr.) Lloyd, caused decreases in the concentration of pinosylvin that were concurrent with red stain formation in infected heartwood meal, but were not associated with maximum absorption shifts. The non-laccase-producing brown rot fungus, Coniophora puteana Schum. ex Fr., caused a maximum absorption shift of pinosylvin from 310 to 320 mμ. However, the concentration of altered pinosylvin did not decrease below that of pinosylvin in the control. All fungi were living at the conclusion of the experiment.
A previously unnamed species of Cyathus from the Cypress Hills, Alberta
Authors: Brodie Harold J.
Published: September 2008

A readily recognized species of the Nidulariaceae is described as Cyathus annulatus Brodie. The fungus is taxonomically related to Cyathus striatuts and to C. helenae, the only other striate or plicate species known to occur in temperate North America. C. annulatus, recognized at present only from the Cypress Hills of Alberta, is characterized chiefly by a distinctive deep-brown ring which colors the inner surface of the lip of the fruit body, and by the shape of the basidiospores, which ranges from spherical to ovoid to elliptical.
Vegetation and frost activity in an alpine fellfield on the summit of Plateau Mountain, Alberta
Authors: Bryant J. P. , Scheinberg Eliyahu
Published: September 2008

An ordination of alpine fellfield vegetation of the Highwood Range of Southwestern Alberta, Canada, revealed that it varies continuously in response to frost activity gradients of two scales: (1) annual or historic congeliturbation which has produced sorted patterned ground structures similar to those found in arctic tundra and some temperate zone alpine tundra regions, and (2) diurnal congeliturbation which produces frost boils within the larger sorted patterned ground structures.Long-term frost activity has produced a gradient of ground covered by rock which is associated with the major separation of stands. Along this gradient, vegetation changes gradually from stands dominated by epipetric lichens such as Alectoria minuscula to a Carex–Cetraria alpine turf.Microenvironments produced by the borders of patterned ground features result in a diurnal frost activity gradient associated with the Y-axis of the ordination. The vegetation responds to this gradient as a successional sequence. This sequence runs from denuded frost boils dominated by terricolous lichen species such as Lepraria neglecta and flowering plants such as Salix nivalis to a closed Carex–Cetraria alpine turf. Since reversion to a frost boil may occur at any point in the sequence, this succession seems to be partially a cyclical phenomenon.The degree of soil profile formation corresponds to the degree of vegetational development. Active frost boils contain shallow lithosols which develop into poorly developed Alpine Turf soils with progressive vegetation stability.
The photosynthetic carbon metabolism of Zea mays and Gomphrena globosa: the location of the CO2 fixation and the carboxyl transfer reactions
Authors: Berry J. A. , Downton W. J. S. , Tregunna E. B.
Published: September 2008

Zea mays and Gomphrena globosa form labeled aspartate and malate (C4-acids) via β-carboxylation of P-enolpyruvate during photosynthesis. Studies of the redistribution of 14C in pulse- and chase-type feedings of 14CO2 indicate that most labeled phosphorylated compounds are formed from the C4-acids. A mechanism involving CO2 as a transitory intermediate is advanced to explain the carboxyl transfer from the C4-acids to 3-phosphoglyceric acid (3-PGA). In this model, CO2 is generated through the oxidative decarboxylation of malic acid by "malic" enzyme, and is refixed by RuDP carboxylase to form 3-PGA. The pattern of labeling of photosynthetic products, the extractable enzyme activities, and the gas exchange properties of these plants appear to be consistent with this proposed sequence of reactions. The location of 14C-labeled compounds was determined by radioautography, and by nonaqueous density gradient separation. Differential grinding was used to study the location of some photosynthetic enzymes. These indicate that CO2 fixation by β-carboxylation occurs in the leaf mesophyll. The carboxyl transfer and the reactions leading to the photosynthesis of starch appear to be confined predominantly to the bundle sheath cells. Rapid transport of C4-acids from the site of CO2 fixation in the mesophyll to the bundle sheath may occur by plasmodesmata.
Chemical dedikaryotization of Coprinus myceliocephalus (Agaricales)
Authors: McClaren Milton
Published: September 2008

The dikaryotic mycelium of the homothallic basidiomycete Coprinus myceliocephalus Lange was treated with chemicals known to induce dedikaryotization. Two monokaryotic isolates were recovered from mycelia grown for 16 weeks in 0.042% sodium arsenate in a solid basal medium and one isolate was recovered after 3 weeks from a liquid medium containing 0.5% cholic acid. The monokaryotic cultures did not form basidiocarps, although the dikaryotic mycelium regularly fruited in culture. Monokaryotic cultures did not revert to the dikaryotic condition nor did mating occur between the paired monokaryotic forms.
Aspergillus elongatus sp. nov. from Indian alkaline soils
Authors: Rai J. N. , Agarwal S. C.
Published: September 2008

The name Aspergillus elongatus sp. nov. has been given to a new species from usar soils collected from Lucknow, India. Placement of this species in the present group classification of the genus Aspergillus is difficult because of the presence of green conidial heads, colorless conidiophores, subglobose to elongate vesicles with biseriate sterigmata, and elongate hülle cells.
Formate metabolism and betaine formation in healthy and rust-infected wheat
Authors: Bowman Margaret S. , Rohringer R.
Published: September 2008

Formate-14C was fed to detached primary leaves of wheat and the distribution of activity among various fractions was examined after 2 to 26 h of metabolism in the light or 4 h of metabolism in the dark.All samples contained activity in free neutral, acidic, and basic compounds. The radioactive metabolites in the basic fraction were examined in detail. Initially, in the light, glutamate, aspartate, serine, and an unknown, chromatographically similar to, but not identical with histidine, contained most of the activity. Activity in betaine increased with time until, at 26 h, it contained nearly half of the activity in this fraction. Following dark metabolism, most of the activity resided in glutamate and serine. Glycine was not radioactive, and most of the activity in serine resided in carbon 3, indicating that formate served as a precursor of C1-units that were used for serine synthesis. Activity was also detected in a number of other amino acids and choline, both in the light and dark.A comparison of formate-14C metabolism in the dark in stem rust resistant and susceptible wheat leaves revealed that betaine, lipids, nucleic acid bound adenine and guanine, and a protein-containing residue from rust-infected susceptible leaves contained much more activity than the corresponding components from healthy susceptible or from healthy or rust-infected resistant leaves.Activity from glycine-2-3H, methionine-14CH3, serine-3-14C, ethanolamine-1,2-14C, and choline-14CH3 was incorporated into betaine in the dark, but was not detected in sarcosine or dimethylglycine. These results support the view that betaine was synthesized from glycine via serine, ethanolamine, and choline with methionine as the methyl donor, and not by direct N-methylation of glycine.Betaine-14CH3 was translocated but not metabolized in healthy or rust-infected primary leaves of wheat, or in aerial portions of adult wheat plants. In these wheat tissues, betaine would thus appear to be a metabolic end product.
The effect of rapidly changing light on the rate of photosynthesis in largetooth aspen (Populus grandidentata)
Authors: Pollard D. F. W.
Published: September 2008

Net photosynthesis by largetooth aspen was measured at each of four levels of irradiance, 3.4, 8.2, 22.6 and 73.1 W m−2 (0.4–0.7 μ), and during interchange of equal periods of these same levels. The periods between interchange ranged from about 0.2 to 300 s. All measurements were made between 17 and 19 °C; ventilation rate across leaves was equivalent to 1.5 m s−1. Photosynthesis was lower during interchange of long periods; depending on the irradiance levels selected, shorter periods led to increases in photosynthesis of up to 50%. Sometimes a recovery in photosynthesis occurred with the longest periods. The greatest changes were observed when one irradiance sequence was well below saturation level and the other was at or above saturation. Measurements of light regimes in three forest types showed that, during moderate winds at least, fluctuations with periods of between 0.1 and 100 s are commonplace. However, the effects of fluctuating irradiance on net photosynthesis may be important for growth and regeneration only where canopy height and spacings result in bright light flecks on other wise dark forest floors.
Apparent heterokaryosis in Alternaria dauci
Authors: Netzer David , Kenneth Robert G.
Published: September 2008

Auxotrophic isolates of Alternaria dauci (Kühn) Groves & Skolko, deficient in thiamine, were frequently isolated from naturally infected carrot leaves from various regions of Israel. Such isolates retain their pathogenicity. Sixth-generation single-conidial subcultures of such isolates still retained their inability to grow on minimal media, as did these isolates after inoculation of and reisolation from carrot leaflets.Individual hyphae separated from germinating conidia behaved in accordance with their origin, i.e., those from conidia derived from auxotrophic isolates were incapable of growth on MM and vice versa, indicating that the multinucleate conidium of A. dauci is homokaryotic.By plating together prototrophic and auxotrophic conidia, apparently heterokaryotic hyphae were obtained; such colonies yielded conidia which again segregated into the original parent types (producing either auxotrophic or prototrophic colonies). The use of two independent markers (auxotrophic vs. prototrophic and crystal-producing vs. non-crystal-producing) in another synthesis experiment gave data supporting the view that heterokaryosis rather than heteroplasmosis was involved.
Growth of Wallrothiella arceuthobii on artificial media
Authors: Parker A. K.
Published: September 2008

Ascospore germination and growth of Wallrothiella arceuthobii (Peck) Sacc. on artificial media is reported. Germination was enhanced by yeast extract or by increasing the agar content of media. Yeast extract was required to sustain growth.
Chlorosis of planted Engelmann spruce seedlings unrelated to nitrogen content
Authors: Ronco Frank
Published: September 2008

Shade-tolerant Engelmann spruce (Picea engelmannii Parry) seedlings generally became chlorotic when exposed to direct sunlight under several different growing conditions, whether grown in pots, in plantations, or in transplant beds at high or low elevations. Shaded seedlings under the same growing conditions remained a normal green color. Chlorosis was attributed to solarization, not to nitrogen deficiency. That conclusion was supported by the fact that the nitrogen content of shaded and unshaded seedlings was similar regardless of the growing conditions.
Reproductive systems and colonization in Canadian weeds
Authors: Mulligan Gerald A. , Findlay Judy N.
Published: September 2008

Flowers of 65 Canadian weeds were bagged to determine if external pollinators were needed for seed set. All of the 33 annual weeds studied, and 21 of the 23 biennials and caespitose perennials, set viable seed within pollination bags. None of the rhizomatous or stoloniferous perennial weeds studied set viable seed beneath the bags. It was concluded that self-fertilization in annual, biennial, and caespitose perennial weeds, and in a few instances, agamospermy in caespitose perennials, are factors that help make them successful weeds. Perennial weeds that can persist and spread in newly created disturbed habitats by virtue of their superior powers of vegetative reproduction are not self-compatible.
Techniques for demonstrating accumulation of zoospores of Phytophthora species on roots in soil
Authors: Mehrotra R. S.
Published: September 2008

Techniques are described for demonstrating accumulation of zoospores of Phytophthora species in soil. One involves accumulation on cellulose acetate membrane interposed between root and zoospore suspension. Accumulation of zoospores corresponded with the region between the root apex and root hair zone. In the other technique a fluorescent dye is used to distinguish zoospores and their germ tubes after the watering of pots of seedlings with zoospore suspensions and subsequent careful removal of these seedling roots for examination. In general the zoospores of P. drechsleri and P. megasperma var. sojae accumulated both on host (resistant and susceptible varieties) and non-host plant roots in soil, indicating the accumulation phenomenon to be non-specific.
Wardomyces aggregatus sp. nov. and its possible relationship to Gymnodochium fimicolum
Authors: Malloch David
Published: September 2008

A new species of Wardomyces, W. aggregatus, is described and compared with Gymnodochium fimicolum Massee and Salmon. Although Gymnodochium may well represent an earlier name for species of Wardomyces there is apparently no authentic material available to substantiate this hypothesis.
Influence of metabolites produced by explants of carrot, potato, lettuce, and cauliflower on the growth of other explants
Authors: Barker W. G.
Published: September 2008

Explants of potato tuber medulla, carrot root phloem, lettuce stem, and cauliflower inflorescence stem were grown on White's (1943) medium supplemented by 20% (v/v) whole coconut milk and 0.5 mg/l α-naphthaleneacetic acid. Subsequently, the original tissues were removed and fresh explants of the same four species were cultured on the medium. Additionally, these tissues were explanted in pairs, in threes, and in fours within the same bottle.The rate of growth (but not the form of development) was influenced by the precedent growth and to a lesser extent, by the simultaneous growth of tissues of other species on the same medium. No chemical identification of the active compounds has been made.
Apodospora, a new genus of the Sordariaceae
Authors: Cain R. F. , Mirza J. H.
Published: September 2008

Apodospora is a new coprophilous genus of the Sordariaceae with dark, ostiolate perithecia. The eight-spored ascus has a conspicuous thickened ring in the apex. The asci are mixed with abundant filiform paraphyses. The ascospore has one dark cell and no hyaline cells. They are surrounded by a gelatinous sheath and have a single apical germ pore. The three new species described and illustrated are A. simulans (type of genus), on moose dung, Ontario, Alberta, Idaho, and South Dakota; A. thescelina, on rabbit dung, Wyoming; and A. viridis on rabbit dung, Mexico.
Photomorphogenesis of Osmunda cinnamomea cultured leaf primordia
Authors: Haight Thomas H. , Kuehnert Charles Carroll
Published: September 2008

In the present study, the techniques of sterile organ culture have been applied to a problem in photomorphogenesis. The organs of culture were determined leaf primordia of the cinnamon fern, Osmunda cinnamomea L. The cultured primordia were subjected to various monochromatic radiations in an attempt to determine the pigment system(s) active in the morphogenesis of these organs.The presence of a blue absorbing pigment system (P420) in these organs is shown by the suppressive effect of blue irradiation on primordial elongation. Elongation of primordia is promoted most by white light followed closely by far-red irradiation. The elongation data have led to the identification of a second pigment which controls a photomorphogenic event in this plant system; this pigment absorbs maximally in the far-red region of the spectrum (P730). Analysis of the histological and fresh weight gain data suggest the interpretation that in cultured cinnamon fern leaf primordia control of these morphogenic events is governed by a third photoreceptor pigment which absorbs maximally in the yellow region of the visible spectrum (P580). The effect of monochromatic radiations on crozier development also has been examined.
Structural and developmental aspects of cycloheximide effects on the chloroplasts of Euglena gracilis
Authors: Ben-Shaul Y. , Ophir Ilana
Published: September 2008

Low concentrations of cycloheximide (6 μg/ml) inhibited cell division of Euglena gracilis. Chlorophyll content and the ability of the cells to form colonies, however, were unaffected. Higher concentrations (10–20 μg/ml) were lethal. In dark-grown cells exposed to light in the presence of 8 μg/ml cycloheximide, cell division stopped but the transformation of proplastids into chloroplasts (greening) was only partially affected. Greening of dark-grown non-dividing cells exposed to light in the presence of cycloheximide was inhibited proportionally to the concentration of the drug. With the highest concentration used (20 μg/ml) no chlorophyll was synthesized and the transformation of proplastids to chloroplasts was prevented.It was concluded in accordance with previous suggestions that cycloheximide affects the plastids through its effect on the cytoplasm and that the inhibition of chlorophyll synthesis is due to prevention of thylakoid formation.
The translocation of sugars in Cucurbita melopepo. V. The effect of leaf blade temperature on assimilation and transport
Authors: Webb J. A.
Published: September 2008

The primary leaf blades of Cacurbita were exposed to 14CO2 for 15 s at different temperatures between 0 and 55° and the assimilation, metabolism, and translocation of 14C studied for periods of 5 min to 1 h. There was little significant change in net assimilation between 15 and 45°, but at 10° or lower and at 55° there was an appreciable decrease. The qualitative pattern of 14C incorporation into the ethanol-soluble fraction of the blade remained undisturbed by a temperature change from 0 to 45° but the rate of incorporation was significantly reduced at the lower temperatures. Sucrose, stachyose, and raffinose were predominantly labeled throughout except at 55° when 14C-malate predominated. Translocation from the blade was more sensitive to temperature change. At 15° and below, movement became restricted. At 5° or lower, and at 55° transport was almost completely inhibited. Between 25 and 45° there was little change in transport rate. Sucrose, stachyose, and raffinose were the major compounds translocated throughout the temperature range permitting movement. At lower blade temperatures development of the 14C-gradient in the petioles and the 14C distribution reflected the diminished rate of 14C assimilation and mobilization in the blades. The response of 14C translocation from the leaf blade to temperature change closely resembled that previously obtained in other transporting regions of the plant.
Rooting cofactors, indoleacetic acid, and adventitious root initiation in mung bean cuttings (Phaseolus aureus)
Authors: Jackson Michael B. , Harney Patricia M.
Published: September 2008

Rooting responses by 7-day-old mung bean cuttings to indoleacetic acid (IAA) and rooting cofactor substances from Pelargonium were studied. Increasing concentrations of IAA (30–120 mg/l) were shown to induce increasing numbers of adventitious roots (10–100 roots per cutting). Fractionated methanolic extracts from Pelargonium tissue promoted rooting in the presence of IAA but no significant effect was detected when the extracts were assayed alone. This rooting cofactor activity was attributed to components tentatively identified as phenolic by reactions with chromogenic reagents.
Production of male gametes and auxospores in a polymorphic clone of the centric diatom Cyclotella
Authors: Schultz Mary E. , Trainor Francis R.
Published: September 2008

Vegetative cells of a Cyclotella clone (03A) form male gametes and auxospores in response to salinity changes in the medium. Two different valve patterns which characterize described species of diatoms, Cyclotella meneghiniana and C. cryptica, may occur during clonal development of the auxospores of clone 03A. Evidence is presented which indicates that the valve morphology is environmentally controlled. This polymorphic clone is distinguishable from either species on the basis of the morphology of its male gamete. It has a male gamete which is anteriorly uniflagellate. The male gametes of both C. meneghiniana and C. cryptica are posteriorly uniflagellate.
Seasonal biochemical changes in the living bark and needles of red pine (Pinus resinosa) in relation to adaptation to freezing
Authors: Pomeroy M. K. , Siminovitch D. , Wightman F.
Published: September 2008

Studies of physiological and biochemical changes associated with the seasonal cycle of frost hardiness in the living bark and needles of red pine (Pinus resinosa Ait.) indicate that seasonal changes in soluble protein (borate buffer) and in the rate of incorporation of radioactive leucine into protein are closely correlated with the changes in hardiness. The seasonal cycles of carbohydrates and amino acids do not appear to be closely related to hardiness in red pine. The results support the view that the development of hardiness in woody plants is associated with the augmentation of total cellular protoplasm.
Effects of water stress on induction and secretion of cellulase and on branching in the water mold Achlya ambisexualis
Authors: Thomas D. des S.
Published: September 2008

Water stress inhibits the branching response of the water mold Achlya ambisexualis to the sexual hormone antheridiol. The relative sensitivities of the experimental parameters to water stress are as follows: branching > cellulase secretion > cellulase induction. Secretion of cellulase is completely inhibited by a 0.3 M concentration of osmoticum.
The electrophoretic patterns of proteins extracted from spores and mycelium of two Drechslera species
Authors: Shipton W. A. , McDonald W. C.
Published: September 2008

Electrophoresis of protein extracts from spores and mycelium of two Drechslera species (D. erythrospilum and D. teres) was carried out on polyacrylamide gels. Spores were harvested from V-8 juice agar and mycelium from V-8 juice broth cultures. One or two band differences were found between electrophoretic patterns of spore extract and mycelial extract depending on the species. Interspecies differences in patterns were no greater than intraspecies differences. The results are discussed, and it is suggested that the method of polyacrylamide gel electrophoresis of proteins is unsuitable as an aid to fungal taxonomy in its present state of development.
Phaeoseptoria contortae sp. nov. on Pinus conforta from Alberta
Authors: Parmelee J. A. , Hiratsuka Y.
Published: September 2008

A fungus, Phaeoseptoria contortae sp. nov., is described and illustrated on the needles of Pinus contorta Dougl. from Alberta. The type specimen shows partial association with the needle-cast fungus Davisomycella ampla (Davis) Darker but the nature of the association is not known.
Morphogenetic studies on excised leaves of Osmunda cinnamomea: histological studies of leaf development in sterile nutrient culture
Authors: Caponetti James D. , Steeves T. A.
Published: September 2008

Leaf primordia of Osmunda cinnamomea L. explanted to a culture medium of simple composition at the end of three of their five seasons of development, complete their normal morphogenetic sequence but produce mature leaves of greatly reduced size. A histological study of the ground tissues of the rachis of cultured leaves reveals that, at least in these tissues, the size reduction results from a diminished cell number rather than from reduced cell elongation. It is apparent that, at every stage of development, cell division is greatly curtailed and that cell elongation begins precociously. Nevertheless, the pattern of development, including the distribution of mitotic activity at critical stages in the morphogenesis of the leaf, is normal. It is concluded that the effects of isolation upon leaves at this stage of development are quantitative ones upon the extent and duration of cell division and cell elongation.
An endopeptidase of bean leaves
Authors: Racusen David , Foote Murray
Published: September 2008

Bean leaves yielded an enzyme which hydrolyzed casein and hemoglobin to large peptide fragments. The protease exhibited maximal activity at pH 9 to 10, an isoelectric point of 8.8, and a molecular weight of about 100 000. During leaf growth the protease increased in a manner suggestive of a developmental role in the control of protein content.
Taxonomy of Phomopsis boycei and its relationship to Potebniamyces balsamicola
Authors: Funk A.
Published: September 2008

It is shown that two varieties of Potebniamyces balsamicola Smerlis cause stem cankers of fir (Abies spp.). Although identical in their perfect states, the two fungi differ from each other in their conidial states. The conidial state of P. balsamicola var. balsamicola, previously described but not named by Smerlis, is herewith named Phacidiopycnis balsamicola sp. nov.; the conidial state of Potebniamyces balsamicola var. boycei var. nov. is Phomopsis boycei Hahn, which is here transferred to the genus Phacidiopycnis. The genetic connection between Phomopsis boycei and Potebniamyces balsamicola var. boycei is confirmed by culture.
Relationship between transpiration and cambial activity in Abies balsamea
Authors: Little C. H. A. , Eidt D. C.
Published: September 2008

Using an antitranspirant (abscisic acid) and a transpiration promoter (Floralife), a positive correlation was found between the rates of transpiration and cambial activity in cuttings of balsam fir, Abies balsamea (L.) Mill. Differences in transpiration rate were not due to differences in xylem production.
The catechol oxidase of bean leaves (Phaseolus vulgaris)
Authors: Racusen David
Published: September 2008

Bean leaf catechol oxidase was studied with a new colorimetric assay system. The enzyme, though specific for o-diphenols, had a relatively low affinity for catechol. Borate, which complexes with catechol, inhibited the enzyme. Results obtained with DEAE chromatography and sucrose density gradient electrophoresis indicated that the enzyme consisted of a group of isozymes whose assay was independent of contaminating peroxidase. Both catechol oxidase and peroxidase increased during leaf expansion.
Observations on growth of long shoots in Larix laricina
Authors: Clausen J. Johanna , Kozlowski T. T.
Published: September 2008

Development of long shoots of Larix laricina (DuRoi) K. Koch was studied. By the end of the growing season the mature long shoot had both basal and stem needles. All the basal needles were preformed in the unexpanded bud. About half the stem needles were preformed and the rest were initiated during the current growing season. Slight external morphological differences were apparent between oldest preformed and youngest non-preformed needles at maturity. However, since the transition was gradual and all intermediates were present, it was concluded that leaf dimorphism did not occur.
Structure and seasonal development of secondary phloem of Juglans regia
Authors: Schaad Norman W. , Wilson E. E.
Published: September 2008

In Persian walnut (Juglans regia L.), as in other deciduous dicotyledonous trees, a small (0.5 mm) amount of secondary phloem is functional for only one season and a large amount is nonfunctional. In 1968 in Central California the cycle of phloem development began in late February and ended sometime before mid-October. The phloem annual ring was composed of distinctive tangential bands, allowing easy distinction of seasonal growth increments. Each growth increment could be divided into early- and late-season tissue. Early-season phloem, composed principally of large sieve tubes, was separated from late-season phloem by a band of fibers. The late-season phloem was composed of a mixture of narrow sieve tubes, parenchyma cells, and, occasionally, an incomplete tangential band of fibers. The annual rings were not crushed except for the early-season phloem, which was somewhat compressed by growth of the woody cylinder. The bark of walnut becomes thicker with age because of this and the enlargement of parenchyma cells.
Pathological anatomy of the bacterial phloem canker disease of Juglans regia
Authors: Schaad Norman W. , Wilson E. E.
Published: September 2008

Erwinia rubrifaciens Wilson, Zeitoun, and Fredrickson invades sieve tubes and parenchyma cells of the nonfunctional secondary phloem of Persian walnut, Juglans regia L. Because the sieve plate pores are great enough in diameter to allow passage of the bacteria, the nonfunctional phloem system provides an avenue along which the bacteria moves long distances up and down the bark. Functional phloem, on the other hand, does not exhibit symptoms of the disease nor is it found to contain the bacteria. Although the bacteria invade the ray parenchyma and move radially through these elements to the outer xylem, bacteria are not found to enter the xylem vessels. In culture, E. rubrifaciens produces long flexuous flagella. When taken from inoculated leaf tissue, however, it does not possess flagella. Hence, transport of bacteria from one sieve tube to another appears to be by apoplastic movement. Internal symptoms develop in two stages: a primary stage due to invasion of degenerate sieve tubes, and a secondary stage due to invasion of parenchyma cells and subsequent formation of wound callus. Pressure from wound callus induces vertical cracks in the bark. A slimy substance containing the bacteria exudes through the cracks to the bark surface, thereby allowing dispersion of the bacteria.
Mechanisms of pathogenesis in Sclerotium bataticola on sunflowers. II. Pectolytic and cellulolytic enzyme production in vitro and in vivo
Authors: Chan Yu-Ho , Sackston W. E.
Published: September 2008

Pectin methylesterase (PME), endopolygalacturonase (Endo-PG), exopolygalacturonase (Exo-PG), pectin trans-eliminase (PTE), polygalacturonase trans-eliminase (PGTE), cellulase, and cellobiase activities were investigated in culture filtrates of Sclerotium bataticola, and in extracts of inoculated and uninoculated sunflower stems. All of the enzymes except PTE were produced in culture filtrates of the pathogen and in diseased host tissues. Only PME was detected in healthy control plants.
Variations in the inorganic composition of inner bark and needles of loblolly pine with tree height and soil series
Authors: White Jerry D. , Wells Carol G. , Clark Edgar W.
Published: September 2008

A survey was made of the concentration of N, P, K, Ca, Mg, Al, Mn, Zn, Fe, and Cu in inner bark and needles of loblolly pines and the soils in which they grew. Concentrations of K, Al, and Mn in inner bark differed significantly with plots on four soils. However, needle samples seemed to reflect differences in the nutrient status of the soil more readily. Concentrations of N, K, Ca, Mg, Al, Mn, and Zn in inner bark showed statistically significant variation with height of sample on the trunk. Correlations between concentrations of N, K, Ca, Al, and Mn in inner bark and needles on the same tree were significant.
Metabolism of alicyclic acids and phenylpropanoids by uredospores of wheat stem rust and wheat leaf rust
Authors: Jackson A. O. , Samborski D. J. , Rohringer R.
Published: September 2008

Uredospores of wheat leaf rust did not take up or metabolize exogenous supplies of quinate-U-14C, shikimate-U-14C, p-coumarate-α-14C, or ferulate-α-14C. Caffeate-α-14C was converted to an unidentified ether-insoluble component which was recovered from the germination medium.Phenylalanine-U-14C and tyrosine-U-14C were readily taken up by uredospores of both rusts and were recovered from the solvent-soluble and insoluble fractions. No evidence for phenylalanine/tyrosine interconversion was obtained. Radioactivity was not incorporated into glycosides or free and bound esters of phenolic acids when phenylalanine-U-14C or tyrosine-U-14C were used as precursors. Radioactivity was not detected in free phenolic acids when uredospores were fed phenylalanine-U-14C. When tyrosine-U-14C was the precursor, radioactive p-coumarate was detected in the germination medium kept at 20 °C, and radioactive p-coumarate and caffeate were both recovered from the germination medium kept at 30 °C.Extracts of uredospores of wheat stem rust and wheat leaf rust contained shikimate dehydrogenase and tyrosine ammonia-lyase. Quinate dehydrogenase and phenylalanine ammonia-lyase were not detected.
Variation in seedling development of balsam fir associated with seed origin
Authors: Lester D. T.
Published: September 2008

Measurements of total height and frequency of frost damage on 5-year-old trees demonstrated moderate to large variation associated with seed origin. Total height was measured at three nurseries in Wisconsin and Minnesota. Frost damage was measured at one nursery in central Wisconsin. The tallest seedlings were from eastern provenances. The seedlings least damaged by spring frost were from Wisconsin and Michigan provenances. Periodic measurements of shoot elongation indicated that variation in rate of elongation was the chief determinant of variation in total shoot elongation. Variation in time of shoot growth initiation was one cause of observed variation in frequency of frost damage. Variation among maternal progenies from six populations in Wisconsin and Michigan was similar to variation among range-wide provenances.