bluuebunny/crossref_metadata_2025 huggingface dataset:
TRANSLOCATION OF THE PRODUCTS OF PHOTOSYNTHESIS IN SUGAR BEET PETIOLES
Authors: Mortimer D. C.
Published: August 2008

The quantity and kind of radioactive compounds in the blade, main rib, and petiole of sugar beet leaves were determined at intervals up to 3 hours after a 1 minute period during which the blade photosynthetically assimilated C14O2. During the first 5 minutes, radioactive compounds were isolated from the main rib but these were due to the direct assimilation of C14O2by the rib and not to translocation into the rib. After 8 minutes, radioactive sucrose from the blade reached the rib and began to move down the petiole. This movement continued at a steady rate of about 1% of the assimilated C14per minute for about 1 hour. The concentration of C14per 2 cm section of petiole was a linear function of the distance, and this gradient moved down the petiole with an apparent velocity of 50 to 135 cm per hour. After 1 hour, the entire length of the petiole contained radioactive sucrose at a relatively uniform concentration per unit section. Although the blade still contained 40 to 50% of the assimilated C14in sucrose, movement out of the blade was reduced to a very low rate after 1 hour, but radioactive sucrose continued to leave the petiole for an additional hour. The absence of significant metabolism of the radioactive sucrose in the petiole, combined with the changes in gradient of that sucrose as a function of time, suggest that the petiole exerts a relatively passive role in the translocation process.
THE REACTION OF BARLEY VARIETIES TO ASTER YELLOWS VIRUS
Authors: Chiykowski L. N.
Published: August 2008

All 24 varieties of barley tested were found susceptible to both a celery-infecting strain (CAYV) and a non-celery-infecting strain (NAYV) of aster yellows virus transmitted by Macrosteles fascifrons (Stål). Percentage of infection varied among varieties and between virus strains. There was no apparent correlation between degree of susceptibility and barley type, length of incubation period in the plant, or percentage survival of insects on varieties. Symptoms were generally slower to appear for NAYV than for CAYV. Of 3080 seeds harvested from infected plants, 2697 germinated but none of the resulting plants developed aster yellows symptoms. The symptoms produced on diseased plants are discussed and illustrated.
MODERN POLLEN DEPOSITION IN THE NICHICUN LAKE AREA, QUEBEC
Authors: Terasmae J. , Mott R. J.
Published: August 2008

Modern pollen content has been examined in 10 surface samples from the Nichicun Lake area, southwest of Schefferville, Quebec, and from three other localities in the same region. The pollen assemblages obtained reflect with fair reliability the regional characteristics of the northern boreal forest. Long-distance wind transport over several hundred miles is indicated by the presence of occasional ragweed and hardwood pollen grains from south of the boreal forest region. A morphological study of the black spruce pollen found indicates a rather wide range of variability, greater than that found in the pollen of black spruce south of this region.
SECONDARY CONTROL OF CONJUGATION IN TREMELLA MESENTERICA
Authors: Bandoni Robert J.
Published: August 2008

Tests with eight isolates of T. mesenterica Fr. indicate that secondary control of conjugation in this species is by means of diffusible substances, i.e., hormones. The experiments suggest that at least two such substances are responsible for initiation of conjugation tube development. The A and a mating types each produce a substance or substances effective in initiating tube growth in the opposite type. The diffusing substances are nonvolatile, heat stable, and dialyzable; tube length appears to be correlated with the amount of diffusate present. It is suggested that, in addition to the substances initiating tube growth, one or more less stable substances regulate directional growth of the tubes as they approach one another.
EPIDEMIOLOGY AND CONTROL OF DEAD-ARM OF GRAPES
Authors: Willison R. S. , Chamberlain G. C. , Townshend J. L. , Ronde J. H. de
Published: August 2008

Inoculation of pruning wounds on grape with spore suspensions of Phomopsis viticola Sacc. at different times of the year rarely resulted in more than 25% infection. In many cases, incipient lesions and even pycnidia developed shortly after inoculation, but infection did not progress further. Highest infection rates were obtained in the summer months with freshly cut wounds. Wounds that had dried out for several weeks were difficult to infect.Primary infections occurred on young, uninjured, succulent, green shoots. Their incidence and severity were dependent on the inoculum potential resulting from the previous year's infection and on the amount of precipitation in the latter half of May. Discrete primary lesions were nearly always superficial but coalescent ones were more deeply seated and often became perennial. Functional pycnidia were frequently observed in the mature layer of bark on the basal nodes and internodes of 1-year-old canes, the underlying tissues of which were not diseased. Green shoots are considered to be more important infection sites than the pruning wounds made during the dormant season in normal commercial practice.Control measures should include propagation and planting of clean nursery stock as well as a pre-bloom spray program. If the disease becomes established in arms or trunk it is more effective and economical to remove and renew the vine at ground level than to try to save part of an affected vine at a greater risk of reinfection.
WEEDS AS INDICATORS OF PHYSICAL SITE CHARACTERISTICS IN ABANDONED PASTURES
Authors: Dale H. M. , Harrison P. J. , Thomson G. W.
Published: August 2008

The presence of 40 weeds was recorded on 130 sites from Lake Huron, Ontario, to Bangor, Maine. From the occurrence and abundance on these sites, an estimate of a weed's nuisance value was determined. Each site was analyzed for nine physical factors thought to influence the presence of these taxa. The preference of each taxon for each site factor has been recorded in a composite table. The presence of specific weeds as indicative of site conditions in abandoned pastures is discussed.
THE ASCOGENOUS STATE OF SEIMATOSPORIUM (≡ MONOCERAS) KRIEGERIANUM ON EPILOBIUM SPECIES
Authors: Müller Emil , Shoemaker R. A.
Published: August 2008

The pyrenomycete Clathridium tostum (Berk. & Broome) n. comb, is transferred from Lejosphaerella v. Höhnel (= Paradidymella Petrak). Collections of this species on stems of Epilobium rosmarinifolium Hoenck from France, and on stems of Epilobium angustifolium L. from Canada, produced in culture the conidial state Seimatosporium kriegerianum (Bres.) Morgan-Jones & Sutton in Sutton, which, as Monoceras kriegerianum (Bres.) Guba, is the type of Monoceras Guba.
TYPES OF THE PYRENOMYCETE GENERA HYMENOPLEELLA AND LEPTEUTYPA
Authors: Shoemaker R. A. , Müller Emil
Published: August 2008

Hymenopleella sollmannii n. nom. (≡Sphaeria hippophaës Sollmann non Hymenopleella hippophaës (Fabre) Munk) was found to have unitunicate asci with a pulvillus, and a ring that turns blue in iodine. Isolates made from the triseptate, terete, brown ascospores produced pycnidia with annellophores bearing usually four-septate conidia with three brown cells and hyaline end cells each furnished with one short central seta. A comparison with Lepteutypa fuckelii (Nitschke) Petrak revealed that it is readily distinguished by the ascospores, which are narrower, octagonal in section, and furnished with a granular deposit in the middle line of the septa.
PATHOGENICITY OF CORYNESPORA CASSIICOLA ON SOYBEAN
Authors: Seaman W. L. , Shoemaker R. A. , Peterson E. A.
Published: August 2008

Corynespora cassiicola was pathogenic on the roots and hypocotyls of soybean seedlings grown in infested soil at Ottawa. Extensive superficial necrotic lesions developed on seedlings from inoculated seeds planted in the field in mid-May, but few symptoms appeared on seedlings planted in late May and in June. Infected plants were initially stunted but recovered with little effect on size or yield. In controlled temperature studies, severe root and hypocotyl rot were produced on inoculated seedlings at 15–20 °C. Symptoms were less severe at temperatures alternating from 15 or 20 °C to 25–35 °C and were negligible on seedlings kept constantly at 25–35 °C. Optimum growth of the fungus on agar media occurred at 20 °C. At 5 °C and 35 °C conidia germinated, but no appreciable mycelial growth occurred; at 30 °C growth was greatly restricted. Typical symptoms of target spot were produced on the inoculated foliage of soybeans in the greenhouse and in the field, but secondary infection was not observed in the field. Foliage infection occurred on cowpea (Vigna sinensis), sesame (Sesamum indicum), and Hartsville cotton (Gossypium hirsutum) in the greenhouse. C. cassiicola was isolated from overwintered soybean root debris, from the roots of mature field bean (Phaseolus vulgaris), and from the roots of soybean seedlings grown in soil not previously cropped with soybeans.
ON THE MORPHOLOGY AND ANATOMY OF TWO SPECIES OF LEPISORUS (J. SMITH) CHING: L. THUNBERGIANUS (KAULF) CHING, AND L. EXCAVATUS (BORY) CHING
Authors: Khare Prem
Published: August 2008

Morphological and anatomical studies of two species of Lepisorus (J. Smith) Ching, L. excavatus (Bory) Ching and L. thunbergianus (Kaulf) Ching, are described in detail for the first time. Both the plants are epiphytic with small, creeping rhizomes, bearing branched roots and two rows of simple, lanceolate, glabrous, short-petioled leaves. In both cases the roots are diarch, the rhizomes are dictyostelic, and the petioles have many vascular bundles. Leaves have a T-shaped xylem. Large, rounded exindusiate sori are arranged on either side, close to the midrib, in two rows. Sporangia are leptosporangiate and protected by peltate paraphyses. Monolete, bilateral spores with a two-layered granulate exine are present.
DEVELOPMENTAL STUDIES IN THE MICROASCACEAE
Authors: Corlett Michael
Published: August 2008

Patterns of perithecium development and centrum organization in Microascus and Petriella are very similar, indicating a close relationship between these genera. However, the asci of Microascus are found at all levels throughout the centrum, while in Petriella, the young asci are peripheral, adjacent to the pseudo parenchyma of the peridium. This and other differences support the recognition of two distinct genera.
A PRELIMINARY STUDY OF THE CAROTENOIDS IN ACRASIS ROSEA
Authors: Fuller Melvin S. , Rakatansky Rachel M.
Published: August 2008

The amoebae of Acrasis rosea grown on a white mutant of Rhodotorula mucilaginosa contained three colored carotenoids. Two of these were xanthophylls, one being torulene with absorption maxima in hexane at 458, 484, and 518 mμ. The second xanthophyll, the most abundant pigment of the amoebae, was an unknown carotenoid with absorption maxima in hexane at 453, 477, and 508 mμ. A carotene with absorption maxima in hexane at 442, 468, and 500 mμ was also present in small amounts but not identified with any known carotene.It was demonstrated, contrary to a previous report, that the amoebae of A. rosea multiplied and became pigmented on carotenoid-lacking yeasts such as Saccharomyces cereviseae. On such colorless yeasts, the pigments were qualitatively the same as those isolated when A. rosea was grown on the colored wild-type and white mutant of R. mucilaginosa. The synthesis of torulene must then be accomplished, at least in its final stages, by the amoebae of A. rosea.
TAXONOMIC DISTRIBUTION OF AMMONIA-LYASES FORL-PHENYLALANINE ANDL-TYROSINE IN RELATION TO LIGNIFICATION
Authors: Young M. R. , Towers G. H. N. , Neish A. C.
Published: August 2008

A general survey of the plant kingdom and a number of bacterial and animal sources has been made for the enzymes L-phenylalanine ammonia-lyase (EC. 4.1.3.5.) and L-tyrosine ammonia-lyase (EC. 4.1.3.). The above enzymes could not be detected in bacteria, animal tissues, algae, lichens, fungi, or mosses, substantiating the view that their presence may be correlated with the ability of plants to synthesize phenylpropanoid compounds related to lignin. Cereals had the highest content of tyrosine ammonia-lyase, as expected from their known high efficiency in converting tyrosine to lignin. In addition, Chrysanthemum sp. (in which neither enzyme could be detected) has been shown to contain potent, natural inhibitors of these enzymes.
AN EVALUATION OF THE STATUS OF CIRSIUM PUMILUM AND CIRSIUM HILLII
Authors: Moore R. J. , Frankton C.
Published: August 2008

The specific separation of Cirsium hillii and C. pumilum has long been questioned. Their morphology, cytology, and distribution are discussed and it is concluded that two subspecies be recognized: C. pumilum (Nutt.) Spreng. ssp. pumilum and ssp. hillii (Canby) Moore & Frankton. The chromosome number of each subspecies is 2n = 30. Hybrids with the somatic chromosome numbers 31, 32 between ssp. pumilum (2n = 30) and C. horridulum Michx. (2n = 34) have been found in Massachusetts. It is suggested that introgression of C. horridulum into ssp. pumilum may be increasing variability of the latter.
THE EFFECT OF IMBIBITION AND VERNALIZATION ON SOME PARAMETERS OF ROOT GROWTH OF TRITICUM × AESTIVUM L.c.v. RIDEAU AND MARQUIS
Authors: Weinberger Pearl , Ku Thérèse W.
Published: August 2008

The effect of a vernalizing temperature on the early root growth of spring and winter wheats var. Marquis and Rideau was examined after two imbibition periods (5 and 14 hours), and 1–7 weeks of grain chilling.Completion of the thermophase, as verified by two standard biochemical methods, varied with the grain variety and the imbibition period.Four weeks of pretreatment in the cold provided the maximal impetus to germination regardless of the cereal variety, imbibition period, or thermophase requirement.A marked change in selected parameters of growth was observed to coincide with the completion of the thermophase in both grain varieties.
STUDIES IN THE PSEUDOASCOBOLEAE
Authors: Kimbrough James W.
Published: August 2008

Comparative structural and microchemical studies of selected genera of the Pseudoascoboleae (= Theleboleae), i.e. Ryparobius Boud., Ascozonus (Renny) Boud., Thecotheus Boud., Lasiobolus Sacc, Ascophanus Boud., and Thelebolus Tode, revealed that many of the genera were polytypic. Characters presently used to distinguish these genera are considered to be artificial, and true relation ships cut across accepted generic lines.
A SECOND COMPONENT FOUND IN A TURNIP LATENT VIRUS COMPLEX
Authors: MacKinnon J. P. , Lawson F. L.
Published: August 2008

Myzus persicae (Sulz.) transmitted a second component virus from a turnip latent virus complex to healthy Physalis floridana Rydb. seedlings after passage of the complex through turnip (Brassica rapa L.). The symptoms were small yellow specks on the leaves which became more pronounced on new growth when infected plants were cut back. Combined transmissions with the first component, mild chlorosis virus, produced yellow-net symptoms characteristic of the complex.The second component was transmitted from P. floridana to P. floridana by graft and of six aphid species tested, only M. persicae transmitted it. The first component alone was transmitted from the complex by M. circumflexus (Buckton). Only a few plants developed symptoms of the second component after inoculation by aphids, and data from some tests indicated that infected P. floridana may sometimes be symptomless. Both components were transmitted in the persistent or circulative manner and were not sap-transmissible.
TAXONOMY OF VERTICILLIUM SPECIES CAUSING WILT OF HORTICULTURAL CROPS IN QUEBEC
Authors: Devaux A. L. , Sackston W. E.
Published: August 2008

Twenty-three cultures of Verticillium were isolated from 10 species of horticultural plants in Quebec. On the basis of morphological and physiological characters in culture the isolates were grouped into three species: V. albo-atrum R. and B., V. dahliae Kleb., and V. nigrescens Pethybr. These species must be distinguished to eliminate the current confusion on host specialization in Verticillium and the influence of environment on Verticillium wilt.
SPIRAL GRAIN AND ANTICLINAL DIVISIONS IN THE CAMBIUM OF CONIFERS
Authors: Bannan M. W.
Published: August 2008

In the cambium of mature trees a general conformity was found in the orientation of the partition in the pseudotransverse division of fusiform initials through out sectors of varying size. The proportion of divisions deviating from the preferred orientation varied with the tree, the locality, and the species, but was usually less than 10%. As radial accretion followed, periodic reversals occurred in the orientation of anticlinal divisions, the spacing between reversals, in terms of xylem increment, being related to the frequency of anticlinal division. The mean interval shortened as the rate of division rose according to the equation xy = k. While this overall relationship obtained, there was generally some inequality in the relative duration of leftward and rightward orientations of division. In species with grain in the outer wood slanted to the right, a rightward tilt of division persisted for longer periods than a leftward tilt. Conversely, in species with grain slanted to the left, thickness of xylem showing leftward orientation of multiplicative divisions exceeded that with rightward orientation. Changes associated with growth from sapling to adult were studied in Picea, in which genus grain is usually to the left in the inner wood and to the right in the outer wood. Here multiplicative divisions were usually inclined to the left in the growth of the first few years, whereas in the later growth orientation to the right endured for longer periods than to the left. Both orientation of pseudo-transverse division and direction of cell elongation after division seem to be under a general polar control. This apparently is an important element in the induction of spiral grain. Above-average net gain of fusiform initials in the turmoil of cell addition and loss, which accompanies circumferential expansion, may be a contributory factor. Serving to restrain the development of an excessive spirality are periodic reversals in direction of tilt in anticlinal division, and a high ratio of loss of cambial cells relative to the frequency of anticlinal division.
TEMPERATURE AND pH REQUIREMENTS FOR AECIOSPORE GERMINATION OF PERIDERMIUM STALACTIFORME AND P. HARKNESSII OF THE CRONARTIUM COLEOSPORIOIDES COMPLEX
Authors: Powell J. M. , Morf W.
Published: August 2008

Aeciospores of two caulicolous rusts, Peridermium stalacliforme Arth. & Kern (orange- and white-spored) and P. harknessii J. P. Moore, belonging to the Cronartium coleosporioides Arth. complex, were germinated under different temperature and pH conditions. P. stalactiforme germinated from 10 to 25 °C, and P. harknessii from 10 to 30 °C, with optima for both occurring between 15 and 20 °C. Germination was best at pH 6, markedly reduced at pH 5 and 8, and inhibited outside pH 5 to 9 in P. stalactiforme and pH 4 to 9 in P. harknessii. Growth at the optimum temperature and pH for 24 hours resulted in average germ tube lengths of 870 μ and 230 μ for P. stalactiforme and P. harknessii, respectively. P. harknessii initiated germination more rapidly than P. stalactiforme. Germ tubes of P. stalactiforme were long with multiple irregular short branches. The distal end of the germ tube often produced an appressorium with an infection peg. Germ tubes of P. harknessii were short, with one to three regular short branches and no appressoria. Few differences were found between the two color variants of P. stalactiforme. A technique for dispersing spores evenly on media is described.
CYTOLOGY OF THE AECIOSPORES AND AECIOSPORE GERM TUBES OF PERIDERMIUM HARKNESSII AND P. STALACTIFORME OF THE CRONARTIUM COLEOSPORIOIDES COMPLEX
Authors: Hiratsuka Y. , Morf W. , Powell J. M.
Published: August 2008

Cytology of aeciospores and aeciospore germ tubes of two pine rusts, Peridermium harknessii J. P. Moore and P. stalactiforme Arth. & Kern, was compared. In P. harknessii the mycelial cells giving rise to aecia were uninucleate. Young aeciospores were usually binucleate but most of them became uninucleate during maturation. Upon germination, nuclear division and septum formation occurred and germ tubes were divided into two, three, or four cells, each of which usually contained one nucleus. One to three side branches developed and nuclei migrated into them. Basidiospores were not produced. Despite the absence of basidiospores, P. harknessii is interpreted as having an endo-type life cycle with nuclear fusion and meiosis. In P. stalactiforme, aeciospores were binucleate and, upon germination, two nuclei migrated into the germ tube. The nuclei remained undivided during the formation of appressoria and infection pegs. Septa were not observed and branching was dichotomous or irregular.
EFFECTS OF OZONE ON THE FINE STRUCTURE OF THE PALISADE PARENCHYMA CELLS OF BEAN LEAVES
Authors: Thomson William W. , Dugger Jr. W. M. , Palmer R. L.
Published: August 2008

The effects of ozone on the fine structure of palisade parenchyma cells were of two phases. The first phase involved changes in the chloroplast stroma which consisted of either a granulation and an increase in electron density or a formation of ordered arrays of granules and fibrils. In the second phase, there was a general disruption of the cellular membranes and organelles and the cellular contents aggregated in the center of the cells. The characteristic components of this aggregate were remains of the chloroplast membrane system and numerous ordered arrays of granules and fibrils. These changes were identical with those previously observed in cells damaged by peroxyacetyl nitrate and were probably related to the oxidation properties of both molecules. In some cells there was a disruption of the organization of the grana within the chloroplasts.
PHAGE TYPES OF XANTHOMONAS PHASEOLI ISOLATED FROM BEANS
Authors: Sutton M. D. , Wallen V. R.
Published: August 2008

Eight phage types of Xanthomonas phaseoli (E. F. Sm.) Dows. were identified by an experimental phage-typing system using four virulent phages and 310 isolates of this organism. The existence of phage subtypes was also demonstrated by the use of high-titer phage preparations. The phage subtypes could be located geographically. Correlation between strain virulence and phage subtype was demonstrated. Polyvirulent phage Pg 176 for X. phaseoli var. fuscans used in the typing system was partially characterized. The incidence and distribution of phages for strains of X. phaseoli and X. phaseoli var. fuscans in soil samples from southwestern Ontario from 1962 to 1965 were determined. The low ecological significance of soil-borne phage was demonstrated. Seventeen phages for X. phaseoli were isolated from 13 soil samples with the aid of enrichment, none without.
THE INTERACTION OF THE SEED COAT AND GIBBERELLIC ACID IN THE GERMINATION OF DATURA FEROX L.
Authors: Sánchez R. A. , Soriano A. , Slabnik S.
Published: August 2008

Gibberellic acid (GA) eliminates the germination blockage in photoblastic Datura ferox seeds. With decoated dormant seeds, maximum response to GA can be obtained with only 24 hours treatment with this substance, if it is preceded by a period of pretreatment in water. This indicates the need for certain metabolic processes to take place if GA is to have an effect. These processes do not take place or do so at a much slower rate if intact seeds are pretreated in a similar fashion. As afterripening proceeds, the need for pretreatment and the effect of the seed coat are less evident. This behavior is very similar to that displayed by this species in relation to red light. It is possible that the modes of action of red light and GA have certain points of contact. These may be linked to the metabolic processes which take place during the first 48 hours incubation, and it is on them that the seed coat has its effect.
THE GROWTH AND DIVISION OF CELLS IN RELATION TO MORPHOGENESIS IN FERN GAMETOPHYTES: II. THE EFFECT OF BIOCHEMICAL AGENTS ON THE GROWTH AND DEVELOPMENT OF PTERIDIUM AQUILINUM
Authors: Sobota A. E. , Partanen C. R.
Published: August 2008

The development of the gametophyte of Pteridium aquilinum was examined in the presence of several biochemical agents. These compounds, by virtue of their influence on the processes of cell division and cell elongation, brought about a change in the gross morphology of the gametophyte. It was thus reconfirmed that a change in the form of the gametophyte may be explained in terms of differential cell behavior. This interpretation was extended to include the response of the gametophytes to several amino acid and nucleic acid analogues. It was also demonstrated that there is no quantitative increase in protein concentration associated with the development of a 2-dimensional structure and it was suggested that an examination of gametophyte morphology in terms of an interaction of cell division and cell elongation may provide a better insight into the problem of gametophyte morphogenesis.
IN VITRO GERMINATION AND POLLEN TUBE GROWTH OF MAIZE (ZEA MAYS L.) POLLEN.: I. CALCIUM AND BORON EFFECTS
Authors: Pfahler P. L.
Published: August 2008

Pollen grains from the single cross hybrid Wf9 × H55 were cultured on an artificial medium containing 15% sucrose and 0.6% bacto-agar supplemented with all possible combinations of three concentrations (0.00, 0.03, and 0.06%) of calcium nitrate and three concentrations (0.00, 0.01, and 0.02%) of boric acid. The combination containing 0.03% calcium nitrate and 0.01% boric acid produced the highest germination (47.9%) and the longest tube length (405 μ). The addition of either calcium nitrate or boric acid alone decreased the germination percentage and pollen tube length. The percentage of grains producing more than one pollen tube was reduced by the addition of calcium nitrate or boric acid singly or in combination. The significance of these results in relation to pollen physiology was discussed.
EFFECTS OF HERBICIDES ON CARBON DIOXIDE UPTAKE BY PINE SEEDLINGS
Authors: Sasaki S. , Kozlowski T. T.
Published: August 2008

Experiments were conducted on effects of herbicides applied to soil or sprayed on shoots on CO2 uptake of 3-year-old Pinus resinosa Ait. seedlings. When applied to the soil, atrazine, monuron, EPTC, and 2,4-D at 20 lb/ac (soil surface basis) or at 4000 p.p.m. variously decreased absorption of CO2. Monuron checked gas exchange most rapidly, with no CO2 uptake measurable after 10 days. Atrazine and 2,4-D inhibited absorption of CO2 at a steady rate. EPTC caused a delayed inhibition of CO2 uptake. DCPA, CDAA, CDEC, and NPA did not affect gas exchange significantly. Monuron applied as a spray depressed CO2 uptake somewhat faster than the soil-applied herbicide. Very rapid inhibition of CO2 uptake was observed after spray application of 2,4-D or EPTC. Atrazine affected gas exchange similarly when applied as a spray or incorporated in the soil. DCPA, applied as a spray, did not affect absorption of CO2 significantly. Possible reasons for differences in CO2 uptake after spray and soil-application of certain herbicides are discussed. Inert ingredients of EPTC applied as sprays at a concentration of 4000 p.p.m. greatly reduced CO2 absorption 3 days after treatment. However, the rapid early depression of gas exchange was followed by recovery, with no obvious deleterious effects on growth up to 3 months after treatment. Some herbicides checked CO2 absorption without chlorophyll breakdown whereas others did not. Monuron completely inhibited CO2 uptake long before any changes in leaf color were evident. In contrast, depression of CO2 absorption by atrazine and 2,4-D rather closely paralleled development of toxicity symptoms, especially chlorosis. These observations suggested that some herbicides such as monuron affected the photosynthetic mechanism more directly than others such as atrazine, 2,4-D, and EPTC.
A VIRUS DISEASE OF RHUBARB IN BRITISH COLUMBIA
Authors: Stace-Smith R. , Jacoli G. G.
Published: August 2008

Severe mottling and stunting was observed in a planting of rhubarb (Rheum rhaponticum L.) in the lower Fraser Valley of British Columbia. A virus was mechanically transmitted from the young leaves of infected plants to a range of herbaceous test plants. The virus was also transmitted by the aphid Myzus persicae Sulz. from rhubarb to petunia and back to rhubarb seedlings. From the symptoms on herbaceous hosts, transmission by aphids, and measurements of electron micrographs, the virus was identified as turnip mosaic virus. Reciprocal serological reactions with type isolates of turnip mosaic virus confirmed this.
GENETIC ASPECTS OF PARASITISM
Authors: Person Clayton
Published: August 2008

In this symposium the author briefly describes genetic interactions between hosts and their parasites. Evidence in support of Flor's hypothesis of gene-for-gene relationships is reviewed. Evolution within parasitic systems is also considered and the author's model system of co-evolution, which combines genetic polymorphism in the host with specific gene-for-gene interactions between host and parasite, is described.
LAYERED STRUCTURE IN THE BITUNICATE ASCUS
Authors: Funk A. , Shoemaker R. A.
Published: August 2008

The bitunicate ascus of Botryosphaeria piceae Funk was found to have a multilayered structure of the endotunica, the hydrophylic, extensible, inner wall of the ascus that functions in ascospore discharge. A similar multilayered endotunica was observed in Botryosphaeria quercuum (Schw.) Sacc. and in Pleospora herbarum (Fr.) Rab. var. herbarum following treatment in 7% KOH solution.
TOMENTELLA AND RELATED GENERA IN NORTH AMERICA: III. NEW SPECIES OF TOMENTELLA AND PSEUDOTOMENTELLA
Authors: Larsen Michael J.
Published: August 2008

The following five wood-inhabiting resupinate tomentelloid Basidiomycetes are described and illustrated as new species from North America: Pseudotomentella longisterigmata, P. vepallidospora, Tomentella brunneofirma, T. sub-alcicola, and T. montanensis. In addition, one new combination is proposed, Pseudotomentella umbrina (Fries) M. J. Larsen.
THE FOLIAR EMBRYOS OF MALAXIS PALUDOSA
Authors: Taylor Roy L.
Published: August 2008

Anatomical examination of the apomictic reproductive structures produced on the tips of leaves in the bog orchid, Malaxis paludosa, has revealed these structures to be an embryo-like structure enclosed in a sterile jacket of cells. It is proposed that these reproductive structures be classified as foliar embryos.
THE ROLE OF LIGHT IN THE FRUITING OF PANUS FRAGILIS
Authors: Miller Jr. Orson K.
Published: August 2008

The role of light in the fruiting of Panus fragilis was explored under controlled temperature and light cycles. No fruiting occurred in the absence of light. A daily light cycle of 1.5 h at 792 ft-c was sufficient to produce fruiting initials, but not mature sporophores. Only at the longest daily light cycle tested, 12 h at 792 ft-c, were mature sporophores produced. The time required was 22–31 days with a daily fluctuating temperature cycle of 22 °C for 12 h followed by 8 °C for 12 h. The development of a pink pigment associated with fruiting initials and young sporophores was strongest at the longer light cycles and almost absent in the short cycles.
INTERPRETATION OF THE MORPHOLOGY OF VARIOUS NATURALLY OCCURRING ABNORMALITIES OF THE INFLORESCENCE OF WHEAT (TRITICUM)
Authors: Sharman B. C.
Published: August 2008

At the onset of inflorescence production, the shoot apex continues to initiate leaf primordia, in the same alternating sequence of the foliage primordia below. Buds arise so precociously in the axils of the primordia that the apex appears to be producing double structures, the so-called "double ridges". The buds rapidly develop into lateral spikelets but the subtending leaf primordia remain rudimentary. After producing some 20–25 such primordia, the apex initiates the glumes and lemmas of the terminal spikelet, still continuing the same distichous sequence. Occasional deviations from the normal pattern of development seem to be the cause of some of the abnormal inflorescences which may be found: for example, the leaf primordium subtending the lowest lateral spikelet may grow out into a small foliage leaf, or the buds may grow out into side heads instead of single spikelets, or the spikelets may become abnormally elongated. Other abnormalities, such as "banana" twin spikelets and Y-forked heads are less easily "explained". The morphology of still unreported abnormalities can probably be predicted. The relative rarity of freak heads spotlights the stability of growth correlation which is achieved during the morphogenesis of normal inflorescences.
Translocation to and accumulation of phosphorus-32 in sclerotia of Sclerotium rolfsii
Authors: Wilcoxson R. D. , Subbarayudu S.
Published: August 2008

Factors affecting translocation to and accumulation of phosphorus-32 in sclerotia of Sclerotium rolfsii were studied. Significantly more of the isotope was translocated and accumulated in the sclerotia when cultures were 6–7 days old rather than 10–11, when the direction of translocation was from old to young rather than from young to old portions of the cultures, and when the cultures were in about 400 ft-c of light rather than in darkness. In addition, the distance that the isotope could be translocated was also greatly influenced by these factors.
Variations in kinetin-like activity in buds of Betula and Populus during release from dormancy
Authors: Domanski Romuald , Kozlowski Theodore T.
Published: August 2008

Levels of kinetin-like activity in dormant buds and buds at various stages of release from dormancy were determined by an assay involving retardation by kinetin-like substances of chlorophyll degradation in tissue of senescing leaves of Raphanus test plants. Dormancy of buds of Betula papyrifera and Populus balsamifera cuttings was broken by exposure to 2-chloroethanol vapor or immersion in warm water. Water extracts of buds at various stages of dormancy were separated by ascending chromatography and active Rf values identified. The amount of kinetin-like activity at various stages of bud dormancy was then determined by observing effects of active Rf values of bud extracts on senescence (chlorophyll retention) of Raphanus plants. Kinetin-like activity was absent in dormant buds of both species and was present in various amounts after dormancy was broken. In Betula, such activity was found primarily at Rf values of 0.3 to 0.5, and secondarily at 1.0. In Populus, kinetin-like activity was found at Rf values 0.5 to 0.6 and 0.9 to 1.0. Kinetin-like activity was greater in non-dormant buds of Populus than in those of Betula. However, the trend of variation in activity with time after breaking of dormancy was similar in both species. After bud dormancy was broken, kinetin-like activity in both species increased progressively until shortly before buds opened, and it decreased thereafter. Evidence is cited that release of buds from dormancy involves a change in the balance of growth regulators, with various growth promoters increasing to overcome the effects of inhibitors. Endogenous cytokinins appear to be involved, together with other growth promoters, in regulating release of buds from dormancy.
The effect of hydrogen ion concentration on the uptake and metabolism of glucose-U-14C by auxin-treated pea root tips
Authors: Kim W. K. , Bidwell R. G. S.
Published: August 2008

Hydrogen ion concentration has been found to have a marked effect on the response of pea root tips to auxins. In addition, auxins have been shown to exert certain specific effects on the metabolism of 14C-labelled glucose and related metabolites. The present experiments show that varying the pH modifies the auxin effects on intermediary metabolism and growth in entirely different ways. It is concluded that the auxin inhibition of growth must operate through a different mechanism than the effect on inter mediary metabolism of glucose.
Developmental biology of sclerotia of Sclerotium rolfsii
Authors: Henis Y. , Chet I.
Published: August 2008

Sclerotial initials of Sclerotium rolfsii reached the maturation phase when transferred onto a new growth medium only if taken from original medium with their surrounding mycelium; but when transferred onto a medium supplemented with 10−4 M iodoacetic acid or 10−2−10−3 M disodium ethylene-diaminetetraacetic acid (Na2EDTA), initials continued their development and became cream-yellow in color even when taken with no mycelium. Sclerotia at the late development phase continued their development and reached maturation when transferred without mycelium onto a non-supplemented medium. Addition of 10−2 ML-cysteine to the transfer medium resulted in inhibition of sclerotial development at both phases, whether or not initials and developing sclerotia were transferred with surrounding mycelium.It is suggested that factors supplied by the mycelium are involved in initiation, development, and maturation of the sclerotia of S. rolfsii. Phenylthiourea can replace these factors only at the phase of initiation whereas iodoacetic acid and Na2EDTA are effective at both initiation and development. All these hypothetic factors are inhibited by L-cysteine.
Rosannia manika gen. et sp. nov. from the Edmonton Formation (Maestrichtian), Alberta, Canada
Authors: Srivastava Satish K.
Published: August 2008

The form-genus Rosannia is designated for triorate pollen, having only one polar projection and three equatorial projections. Rosannia manika n. sp. Is described from the Edmonton Formation (Maestrichtian), Alberta, and is designed as the type species of the genus.
The ultrastructure of Olpidium brassicae. I. Formation of sporangia
Authors: Temmink J. H. M. , Campbell R. N.
Published: August 2008

The ultrastructure of Olpidium brassicae was observed in epidermal cells of lettuce roots from 8 h after inoculation with zoospores until the thalli matured, at 72 h. In early stages of growth the thallus is completely surrounded by the host cytoplasm and separated from it by the thallus ectoplast. A thallus wall begins to form after 36 h and consists of three layers. The thallus contains the usual organelles, a nucleus (many nuclei after about 24 h), mitochondria, ribosomes, and lipid globules. Membrane-bounded structures, the multivesicular bodies, occur throughout the life cycle and are thought to be involved in synthesis of glycogen and lipid, and at a later stage in cleavage of the thallus protoplasm into zoospore protoplasts. One kinetosome in each zoospore protoplast produces a flagellum that is pushed into the cleavage vacuole. An exit tube originates from a bulge in the thallus wall and is closed by an elaborate plug.
Heat-induced callose and lateral movement of assimilates from phloem
Authors: Webster D. H. , Currier H. B.
Published: August 2008

Brief localized heating of cotton cotyledonary petioles increased phloem callose and decreased lateral movement of 14C-assimilates. There was little or no increase in phloem callose when plants were heated directly after a dark period of 16 or more hours. Such heated low-callose petioles had more lateral movement than heated high-callose petioles. Phloem callose and lateral movement returned to normal within 1 day after heating. These results suggest that phloem callose caused part of the decrease of lateral movement in heated high-callose petioles. Excessive phloem callose would be expected to restrict lateral movement, if movement from sieve tubes were via plasmodesmata.
Notes on Potebniamyces coniferarum
Authors: Smerlis E.
Published: August 2008

Potebniamyces coniferarum (Hahn) Smerlis and No. 854 of Sydow's Mycotheca Marchica sub Pseudophacidium decorticans Rehm represent the same fungus. The latter binomial is invalid.
Metabolism of proline-U-14C during germination of barley
Authors: Sane P. V. , Zalik Saul
Published: August 2008

Proline-U-14C injected into the endosperm of 3-day-old etiolated seedlings of Montcalm barley and its mutant was readily translocated to the embryo. Of label present in the embryo, over 65% was accounted for by protein and free amino acids and about 25% was present in organic acids. Proline accounted for over 90% of the label in free amino acids of the endosperm but accounted for less than 50% of label in this fraction in the embryo. Proline was readily converted to glutamate in the embryo. Metabolism of proline was similar in both lines.
Growth analysis of four nursery-grown conifer species
Authors: Driessche R van den.
Published: August 2008

Annual pattern of relative growth rate (RGR) and stem extension growth were examined in four 1-year-old conifer species grown at two nurseries. Net assimilation rate (NAR) and needle area ratio (F) were calculated for a 14-day period in June. Seasonal patterns of RGR in Douglas fir and Sitka spruce were similar, but RGR of white spruce was lower and showed a different pattern. Seasonal fluctuations in RGR may have been associated with changes in rate of stem extension growth in Douglas fir and Sitka spruce, but not in white spruce or hemlock. Differences in NAR had a greater effect on RGR than differences in F during June. In particular, low RGR was mainly due to low NAR in white spruce.
Sexuality and mycelial characteristics of Cyathus helenae and the related fungus Cyathus striatus
Authors: Olchowecki Alexander , Brodie Harold J.
Published: August 2008

A recently described bird's nest fungus, Cyathus helenae Brodie, was grown in pure culture. Monosporous mycelia developed irregularly pigmented areas of a dark umber color and most displayed a marked tendency to produce a variety of saltant types. Saltants differed from parental mycelia in growth rate, pigmentation, and the amount of aerial mycelium developed. When mated, monosporous mycelia behaved according to a tetrapolar pattern. Mating-type genes were identical in mycelia originating from fruit bodies of widely separated areas. All mycelia of C. helenae were very different in pigment and texture from mycelia of C. striatus (Huds.) Willd. ex Pers. Dikaryotic mycelia were developed in certain matings of monosporous mycelia of C. helenae with monosporous mycelia of C. striatus, but this close genetic relationship is not taken as indicative of conspecificity.
Three new Europhium species with Verticicladiella imperfect states on blue-stained pine
Authors: Robinson-Jeffrey Robena C. , Davidson Ross W.
Published: August 2008

Three new species in the genus Europhium (E. clavigerum, E. aureum, and E. robustum) with Verticicladiella imperfect states are described and figured. Cleistothecia are found on bark, sapwood, and in old beetle galleries of beetle-infested, blue-stained pines, including lodgepole (pinus contorta Dougl. var. latifolia Engelm.), ponderosa (Pinus ponderosa Laws.), limber (Pinus flexilis James), and western white (pinus monticola Dougl.). Europhium clavigerum was found on all hosts, E. aureum on lodgepole, and E. robustum on ponderosa. Perfect states of all three species are similar and species separation is based on differences between the imperfect states. A key is provided to separate the Verticicladiella states of the three new species of Europhium and the Leptographium state of E. trinacriforme Parker.
A morphological study of the red alga Leveillea jungermannioides
Authors: Scagel Robert F. , Chihara Mitsuo
Published: August 2008

A detailed description of the juvenile thallus and male, female, and tetrasporangiate reproductive structures is given for the red alga Leveillea jungermannioides (Hering et Martens) Harvey (subfamily Polyzonieae, family Rhodomelaceae). Morphological evidence is presented to support the systematic position of the genus Leveillea and to indicate affinities with the genera Polyzonia and Dasyclonium (= Euzonielld) in the same subfamily of this group of red algae.
Delineation of isograds in siliceous dolomitic marbles along the Sharbot Lake – Frontenac terrane boundary of the Grenville Province, southeastern Ontario
Authors: Goodwin-Bell Jo-Anne S.
Published: August 2008

This study presents details of the mineralogy and petrology of siliceous, dolomitic marbles of the Sharbot Lake domain along the Frontenac terrane boundary in the Grenville Province of southeastern Ontario. The location of four mineral isograds in the marble and the related univariant reactions were identified in the Almonte – Carleton Place area. Delineation of the isograds is based on detailed mapping, petrographic analysis of coexisting mineral assemblages, and a polybaric T–XCO2diagram calculated using thermobarometric data from associated gneissic rocks, where T is temperature and X is fluid composition. The T–X section is based on a field gradient of 32 °C/km. The isograds correspond to the first appearance of tremolite (5 dolomite + 8 quartz + H2O = tremolite + 3 calcite + 7 CO2), diopside (tremolite + 3 calcite + 2 quartz = 5 diopside + 3 CO2 + H2O), diopside + dolomite (tremolite + 3 calcite = dolomite + 4 diopside + H2O + CO2), and forsterite (diopside + 3 dolomite = 2 forsterite + 4 calcite + 5 CO2). Mineral assemblages above and below each isograd are described and relevant examples are shown. Results of this study are consistent with a mixed volatile fluid of a uniform composition during mid- to upper amphibolite-facies metamorphism.
The origin of the Variscan upper allochthons in the Ortegal Complex, northwestern Iberia: Sm–Nd isotopic constraints on the closure of the Rheic Ocean
Authors: Murphy J. Brendan , Gutiérrez-Alonso Gabriel
Published: August 2008

Northwestern Iberia preserves a stack of allochthons in which the vestiges of a suture zone generated during the Variscan orogeny by the late Paleozoic collision between Laurussia and Gondwana are exposed. Lower allochthons contain Ordovician ophiolite (known as the Lower Ophiolite), and are structurally overlain by Devonian ophiolite (Upper Ophiolite), which are in turn structurally overlain by allochthons containing high-grade metamorphic rocks with continental affinities and Late Cambrian – Early Ordovician protolith ages (known as the Upper Units). Geochemical and Sm–Nd isotopic data from the Upper Ophiolite and the structurally overlying Upper Units exposed in the Ortegal Complex of Galicia show that these allochthons are derived from a variety of mantle and crustal sources and indicate that the suture zone juxtaposes a variety of oceanic assemblages. The general isotopic characteristics of each assemblage are similar to allochthons in other Variscan complexes in NW Iberia suggesting that the allochthons are each derived from a common source and may be regionally extensive. One of the bodies mapped within the Upper Ophiolite (Purrido amphibolite) is a composite body that, in addition to recently identified Mesoproterozoic mafic rocks, is characterized by a juvenile signature at ca. 395 Ma that was chemically modified from coeval intra-oceanic subduction. The very high ϵNdof this Late Devonian ophiolite is typical of several penecontemporaneous ophiolites within the Variscan orogen including the Lizard Complex (Britain) and the Massif Central (France), suggesting derivation from a regionally extensive anomalous mantle characterized by time-integrated depletion in Nd relative to Sm. Paleozoic mafic rocks in the Upper Units have ϵNdvalues typical of Paleozoic mafic rocks in Avalonia, which are thought to have been derived from subcontinental lithospheric mantle (SCLM) that was enriched at ca. 1.0 Ga. They exhibit elevated Th/Yb and Ce/Yb relative to Ta/Yb suggesting that their composition has been contaminated by subduction zone components, although the age of this contamination is unclear. Felsic rocks in the Upper Units were derived by melting of Mesoproterozoic or older (West African?) crust. These data, when combined with other geologic constraints, including the outboard position of the Upper Units relative to the ophiolite, support the hypothesis that the Upper Units collectively represent a crustal fragment that drifted from Gondwana during the formation of the Rheic Ocean, was transferred to Laurussia in Silurian or early Devonian times, and was subsequently thrust over the Gondwanan margin during the closure of the Rheic Ocean and the Variscan orogenesis.