bluuebunny/crossref_metadata_2025 huggingface dataset:
METABOLISM OF AROMATIC COMPOUNDS IN HEALTHY AND RUST-INFECTED PRIMARY LEAVES OF WHEAT: I. STUDIES WITH14CO2, QUINATE-U-14C, AND SHIKIMATE-U-14C AS PRECURSORS
Authors: Rohringer R. , Fuchs A. , Lunderstädt J. , Samborski D. J.
Published: August 2008

Healthy and stem rust infected leaves of two near-isogenic lines of wheat were allowed to metabolize14CO2, quinate-U-14C, or shikimate-U-14C for 22 h in the light.Quinate-U-14C and shikimate-U-14C were interconvertible but differed in their efficiency as precursors of phenylalanine and tyrosine, suggesting that an alternative pathway, not via shikimate, exists from quinate to phenylalanine in wheat leaves. Activity from the cyclites was not incorporated into tryptophan during the metabolic period. Evidently, synthesis of aromatic amino acids in wheat leaves is not restricted to the "classic" shikimate pathway.Infection with rust led to an increase of the carbon How from CO2to shikimate and to higher levels of both quinate and shikimate. This trend was more pronounced in susceptible than in resistant leaves. Moreover, utilization of quinate and shikimate was increased in infected susceptible leaves but was not altered significantly in infected resistant leaves. Resistant and susceptible reacting leaves differed in the distribution of activity derived from quinate-U-14C and shikiniate-U-14C. With shikimate-U-14C as precursor, resistant reacting leaves accumulated activity in unidentified components of the amino acid fraction (Amberlite IR-120 eluate). Susceptible reacting leaves accumulated less activity in these compounds, and healthy leaves contained only traces of activity in them. When either quinate-U-14C or shikimate-U-14C was metabolized by healthy leaves, more activity was recovered in insoluble esters (of ferulate and p-coumarate) than in soluble esters. Resistant reacting leaves accumulated still more activity in the insoluble esters, whereas susceptible reacting leaves contained a proportionately higher amount of activity in soluble esters. Compared with healthy leaves, susceptible reacting leaves always contained less activity, and resistant reacting leaves more activity, in the non-hydrolyzable, insoluble residue.
CHEMOSYSTEMATIC STUDIES IN THE GENUS PICEA (PINACEAE): I. INTRODUCTION
Authors: Rudloff E. von
Published: August 2008

The application of volatile leaf oil analyses in chemosystematic studies of North American spruces was investigated. The optimum conditions for sampling and recovery of oil from the foliage of local Picea glauca (Moench) Voss and P. mariana (Mill.) B.S.P. were determined. Each oil was analyzed qualitatively and quantitatively by gas–liquid chromatography. Single needle analysis was also employed. No qualitative and relatively little quantitative variation was found to occur at different sides or heights of a single tree, between trees of different ages, nor at different harvest times between late summer and early winter. Hence, conditions have been found which give a characteristic terpene distribution pattern which may serve as an independent chemotaxonomic character.
FUNGAL COLONIZATION OF PISUM LEAVES
Authors: Dickinson C. H.
Published: August 2008

Systematic studies on phylloplane microorganisms are required to answer questions concerning pathogenic and saprophytic destruction of leaves. Pisum leaves, which are excellent experimental material, have been examined during the entire growing season of the plants, and beyond, in the first stages of decomposition. Green leaves were not extensively colonized by filamentous fungi. At the onset of senescence, a dramatic increase was observed in the activities of several saprophytes and on newly dead leaves colonization proceeded even more quickly. Cladosporium, Stemphylium, and Alternaria were frequently observed in the first wave of saprophytes. The first two genera sporulated soon after the leaves died. The increase in saprophyte activity was considered to be primarily a result of alterations in leaf physiology though the possibly beneficial influence of changes in various climatic factors may not be neglected.
DEVELOPMENTAL STUDIES ON EUPHORBIA ESULA L.: SOME EFFECTS OF THE NITROGEN SUPPLY ON THE GROWTH AND DEVELOPMENT OF THE SEEDLING
Authors: McIntyre G. I. , Raju M. V. S.
Published: August 2008

The influence of the nitrogen supply on the growth and development of Euphorbia esula L. was investigated by growing seedlings in sand culture at nitrogen levels of 105 p.p.m. (later increased to 210 p.p.m.), 10.5 p.p.m. and 2.1 p.p.m. Shoot height and dry weight and the shoot/root ratio were much reduced by nitrogen deficiency and the outgrowth of lateral buds was completely suppressed at the lowest nitrogen level. Root development proved very responsive. The "heterorhizic" pattern of long and short roots of differing growth potential described from field observations was much less evident under the experimental conditions. Long roots were more numerous and were produced at an earlier stage of development than is usual in the field. These differences increased markedly with the nitrogen supply. The number of lateral roots (of both types) per unit length of the parent roots and the number of shoot buds on the root system were both considerably greater at the higher nitrogen levels. The increase in shoot bud production, however, could be largely attributed to associated effects on the size and mode of development of the root system. Regrowth from buds on the roots, induced by shoot removal, was extremely vigorous in the seedlings treated with high nitrogen but was almost completely suppressed at the lowest nitrogen level.
NORTHERN PYRENOMYCETES: III. WESTERN SPECIES
Authors: Barr Margaret E.
Published: August 2008

This report on the occurrence of a number of western North American species of Loculoascomycetes includes the new combinations and the new name: Wettsteinina andromedae var. cassiopes (Dearn and House) Barr, W. sieversiae (Peck) Barr, and Leptosphaeria hesperia Barr.
TRINUCLEATE CELLS AND OTHER NUCLEAR ABNORMALITIES IN RACE 6 OF OAT STEM RUST
Authors: Craigie J. H. , Burrows V. D.
Published: August 2008

Trinucleate cells may occur sporadically in the uredinial mycelium of infections of race 6 of Puccinia graminis Pers. var. avenae Eriks. and E. Henn. An occasional urediniospore or its germ tube may have three nuclei. Trinucleate cells may divide and give rise to other trinucleate cells. Some tetranucleate cells may also occur and they likewise may divide. The trinucleate condition (groups of three nuclei) may originate: (a) in a binucleate cell by the division of one nucleus while the other remains undivided; and (b) in a tetranucleate cell by the separation (migration) of one nucleus from the other three which remain in a group. Cells with three nuclei occur chiefly in the younger mycelium of an infection and their number may vary widely from one infection to another. Such cells tend to revert to the binucleate condition either by the dissolution of the supernumerary nuclei or by their emigration from the cells concerned. There seems to be a possibility of influencing the number of trinucleate cells in an infection by artificial means.
AN INSTRUMENT FOR MEASURING THE MICRORELIEF OF BARK
Authors: Yarranton G. A.
Published: August 2008

Very accurate cross sections of tree boles were obtained by measuring the radial distances between the inner edge of a metal ring encompassing the tree and its surface. The ring may be adjusted to the horizontal plane. By means of the instrument the distribution of at least one lichen was shown to be correlated with bark microrelief.
AZOLLA PRIMAEVA AND ITS PHYLOGENETIC SIGNIFICANCE
Authors: Hills L. V. , Gopal B.
Published: August 2008

The genus Azolla belongs to the family Salviniaceae of the hydrophytic ferns. It is represented by 25 fossil and 6 extant species.Azolla primaeva (middle Eocene) bears bisexual sporocarps. Microsporangia are almost invariably accompanied by megasporangia, whereas megasporangia, three per sporocarp, commonly occur alone. Microsporangia tend to be located near the main axis, whereas megasporangia occur out to the tips of lateral branches.The evolutionary tendencies within the genus are discussed briefly and it is concluded that section Azolla gave rise to section Rhizosperma. Three possible routes whereby the nine-floated condition of the latter could have been derived are presented: fusion of three megaspores and megaspore apparatuses and abortion of two megaspores; reduction in float number from an ancestral form similar to A. teschiana; the segmentation of the three-floated form into the nine-floated condition. The last hypothesis, with progressive simplification and ultimate elimination of glochidia, is favored. Changes in the glochidia were not synchronous with changes in the megaspore, but occurred later with remnants still present on A. pinnata.
TAXONOMIC SYNOPSIS OF BROMUS SECTION BROMOPSIS (GRAMINEAE) IN ALASKA
Authors: Mitchell Wm. W.
Published: August 2008

The taxonomy of the genus Bromus section Bromopsis in Alaska is summarized. With recent changes incorporated in the treatment the section now includes B. ciliatus (2n = 14), B. richardsonii (2n = 28), B. pacificus (2n = 28), B. pumpellianus ssp. pumpellianus (2n = 56), and B. pumpellianus ssp. dicksonii (2n = 28), all indigenous, and B. inermis (2n = 56), an introduction. A taxonomic key, species descriptions, and comments are provided along with generalized distribution maps of the indigenous taxa.
DEMARCATION LINES IN PAIRED CULTURES OF FOMES CAJANDERI AS A BASIS FOR DETECTING GENETICALLY DISTINCT MYCELIA
Authors: Adams David H. , Roth Lewis F.
Published: August 2008

A study of paired cultures of known parentage within the species Fomes cajanderi, has shown that the dark lines of demarcation which frequently form at the interface of paired colonies constitute a reliable basis for distinguishing genetically distinct mycelia. The presence or absence of demarcation lines as well as line intensity depends upon genetic relationship of the paired cultures and is independent of colony appearance. When cultures of the pair were distantly related demarcation lines formed 95–100% of the time. When cultures were of closest relationship lines formed approximately 50% of the time.
FINE STRUCTURE OF PLASMODIOPHORA BRASSICAE IN SPOROGENESIS
Authors: Williams P. H. , McNabola Sharon S.
Published: August 2008

The vegetative Plasmodium of Plasmodiophora brassicae is contained within host cell cytoplasm. The multinucleate Plasmodium contains numerous large lipid droplets and is replete with mitochondria, dictyosomes, endoplasmic reticulum, and ribosomes. A 250 Å thick osmiophilic plasmodial envelope is characteristic of the vegetative Plasmodium. This envelope is composed of two closely appressed membranes each consisting of a pair of electron-dense layers. As sporogenesis is initiated, the outer membrane of the plasmodial envelope disintegrates, leaving the Plasmodium surrounded by the plasmodial membrane. Nucleoli disappear and numerous vacuoles and vesicles appear in the cytoplasm of the parasite. Vacuoles appear to be formed from invaginations of the plasmodial membrane. These vacuoles become aligned in planes of cleavage around each nucleus, forming the boundaries of each future sporangium. As these vacuoles coalesce, the nucleus of each young resting sporangium becomes surrounded with cytoplasm and is enveloped by the vacuolar membranes. Spines form on the sporangial membrane as aggregates of residual vacuolar material. The sporangial wall is then deposited between the sporangial membrane and the spines. Intact host nuclei, mitochondria, and plastids can be found dispersed among the mature resting sporangia. The host plasmalemma is the only membrane surrounding the mass of resting sporangia. The uninucleate resting sporangium is rich in lipid and contains those organelles found in the vegetative Plasmodium.
CHEMOSYSTEMATIC STUDIES IN THE GENUS PICEA (PINACEAE): II. THE LEAF OIL OF PICEA GLAUCA AND P. MARIANA
Authors: Rudloff E. Von
Published: August 2008

The leaf oils from white and black spruce obtained from different locations in Western and Eastern Canada, Michigan, and Minnesota, have been analyzed by gas liquid chromatography. Both species were found to have a remarkably consistent and distinctive distribution pattern of the leaf oil terpenes. The quantitative variations encountered in samples of the same species from different populations are relatively small and ecological differences are not found to affect the leaf oil composition. Hence, analysis of spruce leaf oils appears to be highly suitable for a study of introgression and hybridization.
DESICCATION AND HEAT RESISTANCE OF THE GREEN ALGA SPONGIOCHLORIS TYPICA
Authors: McLean Robert J.
Published: August 2008

The ability of the green alga Spongiochloris typica to resist desiccation and heat (100 °C for 1 h) was investigated. Desiccation resistance and heat resistance, which were both ephemeral, appeared to be two separate phenomena. A dilution of the nutrients of the medium seemed to favor high desiccation resistance whereas heat resistance was favored by higher concentrations of nutrients. Also, they reached their resistance maxima at different times during the 8-week incubation period. These two phenomena apparently were not related to an accumulation of lipids or carotenoids, nor to the decline of chlorophyll.
Penetration and initial establishment of Nectria galligena in aspen and peachleaf willow
Authors: Zalasky H.
Published: August 2008

Histological studies of artificially inoculated aspen and peachleaf willow revealed that Nectria galligena penetrated the periderm directly. Penetration and establishment in the petiole base and leaf trace was noticeably more rapid than in the periderm. The resulting lesions in all infections were small and usually latent.
A new species of Ceratocystis causing blue-stain in Araucaria araucana
Authors: Butin H.
Published: August 2008

In southern Chile two species of Ceratocystis were found to be responsible for most of the initial blue stain in logs and lumber of Auraucaria araucana (Mol.) K. Koch. The more important Ceratocystis auraucariae Butin sp. nov. and its Verticicladiella conidial state are described and illustrated. This species is characterized by a fast-growing brown mat of mycelium, small, long-necked perithecia, and cylindrical, slightly curved ascospores. Ceratocystis moniliformis (Hedge.) C. Moreau, Melanconiopsis elzoi Speg., Epicoccum nigrum Link, and Cladosporium sp. were found as associated fungi.
Comparative studies on number of leaflets, venation, and epidermal structure in the genus Lathyrus
Authors: Simola Liisa Kaarina
Published: August 2008

A comparison of endemic Lathyrus species of different continents has been carried out with regard to venation, epidermal cell structure, and number of leaflets to apply the information so obtained to phylogenetic considerations. Morphologically primitive Lathyrus species have several leaflets with pinnate venation, and epidermal cells with undulate walls. This type is represented by all the North American endemic species and by some Eurasian ones. Most Eurasian and North African species, however, have only one pair of leaflets, parallel venation, and epidermal cells with undulate walls. The South American species are the furthest advanced in evolution. They have two leaflets with parallel venation, and epidermal cells with straight lateral walls. The endemic species of South and North America thus differ sharply with regard to the characteristics examined while Eurasian and North African species show relationship to species of both South and North America. The distribution of the leaf characteristics studied and evolution of species within this genius might have its cause in historical geology.
The genetics of Cochliobolus spiciferus. I. Genetic inhibition of perithecial and ascus formation
Authors: Webster R. K. , Nelson R. R.
Published: August 2008

The present investigation showed that certain conidial isolates of C. spiciferus exhibit complete mating inhibition, although the matings consisted of pairings between opposite compatibility types. Other isolates of opposite compatibility produced only sterile perithecia when mated under favorable cultural conditions. It was determined through a genetic analysis that perithecial inhibition in C. spiciferus is conditioned by the presence of the recessive allelic forms, in the homozygous condition in the fusion nucleus at either of two loci designated as I1 and I2. The formation of asci in matings between strains of opposite compatibility was found to be inhibited when both isolates of the mating contain the recessive form of a third gene designated as S.The results are discussed in connection with their significance in assessing the biological relationship of C. spiciferus to other members of the genus Cochliobolus and to members of the genus Curvularia.
The low maximum temperature for growth of the psychrophile Sclerotinia borealis; evidence for the uncoupling of growth from respiration
Authors: Ward E. W. B.
Published: August 2008

The optimum temperatures for growth and respiration of cells of Sclerotinia borealis grown at 0 °C are, respectively, 0 °C and 25 °C while the maximum temperature for growth is approximately 15 °C. It is postulated that at temperatures above 15 °C growth becomes uncoupled from respiration. This is supported by the following evidence. With glucose as substrate, stimulation of O2-uptake by the uncoupling agents 2,4-dinitrophenol and dicoumarol was relatively greater at 5 than at 25 °C. The degree of stimulation at 25 °C varied inversely with the duration of exposure to that temperature while that at 5 °C remained constant. In the absence of glucose, 2,4-dinitrophenol inhibited O2-uptake strongly at both temperatures. Recovery on subsequent addition of glucose was slow. Prolonged exposure to 25 °C in the absence of glucose resulted in a gradual loss of ability to respire or take up glucose. When the distribution of 14C after utilization of glucose-u-14C was determined it was found that relatively only half as much 14C was incorporated into cell material at 25 °C as at 5 °C.
Studies on the production of perithecial stromata by Cordyceps militaris in artificial culture
Authors: Basith Mumtaz , Madelin M. F.
Published: August 2008

Some nutritional and environmental factors which influence the production and maturation of perithecial stromata of Cordyceps militaris (Linnaeus) Link in artificial culture have been studied. The fungus grows vegetatively in defined media with a variety of carbon and nitrogen sources without added vitamins, and can use nitrate as sole nitrogen source, but forms stromata only under special nutritional conditions such as are provided by a medium of sterilized soaked rice grains. Illumination at more than 3 foot-candles is necessary for stromata to be initiated, and an intensity greater than a threshold value between 15 and 90 ft-c is necessary for production of mature perithecia. Temperatures above about 22 °C depress stroma development. So, too, does excessive aeration, which removes a gaseous or volatile stimulatory substance which is produced by the cultures. Media found suitable for stroma production include mineral salt solutions with either starch or sucrose associated with either haemoglobin or casein or peptone. Amino acids, used singly or in mixture, and glucose were not favorable. There was no evidence that fruiting required growth factors. The results support the view that stroma production is favored by media with carbon and nitrogen sources which cannot be assimilated until they have been hydrolyzed, and which consequently sustain favorably low concentrations of assimilable nutrients over a long period.
Taxonomy and distribution of northeast Pacific species of Laminaria
Authors: Druehl Louis D.
Published: August 2008

Ten species of Laminaria are recognized for the northeast Pacific: L. groenlandica Rosenv.; L. farlowii Setchell; L. saccharina (L.) Lamour.; L. setchellii Silva; L. dentigera Kjellman; L. longipes Bory; L. sinclairii (Harvey ex Hooker f. et Harvey) Farlow, Anderson et Eaton; L. ephemera Setchell; L. yezoensis Miyabe; and L. complanata (Setchell et Gardner) Setchell. The specific epithet groenlandica is used for those northeast Pacific plants earlier referred to as L. cuneifolia, pending determination of their specific identity. Laminaria personata Setchell and Gardner is suggested to be conspecific with L. yezoensis, L. cordata Dawson is considered conspecific with L. saccharina and L. platymeris De la Pyl. (sensu Setchell and Gardner) is considered conspecific with L. groenlandica. Four forms of L. groenlandica are recognized for the northeast Pacific. These forms are not considered as legitimate taxonomic entities but are distinguished merely to provide a means of facilitating discussion. The known habitat requirements for all 10 species were broadened excepting those of L. complanata and L. sinclairii, and the known distributions of all species, excepting that of L. groenlandica, were extended.
Inhibition of Poria carbonica by Scytalidium sp., an imperfect fungus isolated from Douglas-fir poles
Authors: Ricard Jacques L. , Bollen Walter B.
Published: August 2008

In a survey of the fungi in heartwood of Douglas-fir poles, three conditions were observed: no fungi, unifungal cultures of Poria carbonica Overh. or related basidiomycetes, and a mixed microbial population. From some apparently sound wood cores, a species of Scytalidium was isolated, usually as a unifungal culture. This organism was distinguished by release of a water-soluble yellow pigment into the agar and production of dark spores as the colony aged. Strong antagonism of Scytalidium sp. to P. carbonica on malt extract agar was attributed at least partly to the production of an antibiotic substance by Scytalidium. There was no evidence of change in the mechanical properties of the wood or of injury to the wood cells as a result of Scytalidium growth. The xylan moiety in the hemicellulose was the preferred energy source observed. Wood chips permeated with this organism and then steamed were not damaged by an actively growing colony of P. carbonica.
The genus Ceratocystis in Ontario
Authors: Griffin H. D.
Published: August 2008

From Ontario hardwoods and conifers, 234 collections were examined for Ceratocystis and associated stains and vectors. Most previously described species, including many type specimens, were also studied.Among morphological characters used to separate species of Ceratocystis, those of the ascospores are the most reliable and are stressed in this study. Three-dimensional examination of ascospores, particularly in species possessing spores with sheaths, is necessary to determine spore shape accurately. Four ascospore sheath types are recognized: uniform, hat-shaped, double-brimmed, and quadrangular.A preliminary survey indicates that the bark-beetles Ips pini (Say) and Orthotomicus caelatus (Eich.) may be principal vectors for several Ceratocystis spp. on Ontario conifers.Based mainly on ascospore characters, a key to 60 species of Ceratocystis is provided. The species C. galeiformis Bakshi, C. obscura (Davids.) Hunt, C. polonica (Siem.) Hunt, and C. serpens (Goid.) C. Moreau are excluded. It is proposed that C. ambrosia Bakshi, C. capillifera (Hedgc.) C. Moreau, C. pluriannulata (Hedgc.) C. Moreau, and C. schrenkiana (Hedge.) C. Moreau be considered synonyms of C. pilifera (Fr.) C. Moreau and that C. vesca Davids. be treated as a synonym of C. olivacea (Math.) Hunt. The following species, described since Hunt's key was published, are included: C. bicolor (Davids, and Wells) Davids., C. brevicollis Davids., C. brunnea Davids., C. brunneocrinita Wright and Cain, C. dryocoetidis Kendrick and Molnar, C. europhioides Wright and Cain, C. falcata Wright and Cain, C. huntii Robinson, C. megalobrunnea Davids, and Toole, C. nigra Davids., C. perfecta Davids., C. tremuloaurea Davids, and Hinds, C. truncicola (Davids.) Griffin comb. nov. Eleven new species are described in this paper.Descriptions, figures, and distribution data are provided for most of the 32 species of Ceratocystis encountered in Ontario. The following previously described species were collected: C. bicolor (Davids. and Wells) Davids., C. brunneocrinita Wright and Cain, C. coerulescens (Munch) Bakshi, C. europhioides Wright and Cain, C.fimbriata Ell. and Halst., C. huntii Robinson, C. ips (Rumb.) C. Moreau, C. major (Van Beyma) C. Moreau, C. minor (Hedgc.) Hunt, C. minuta (Siem.) Hunt, C. nigra Davids., C. olivacea (Math.) Hunt, C. perparvispora Hunt, C. piceae (Munch) Bakshi, C. pilifera (Fr.) C. Moreau, C. sagmatospora Wright and Cain, C. stenoceras (Robak) C. Moreau, C. tenella Davids., C. tetropii (Math.) Hunt, C. truncicola (Davids.) Griffin comb, nov., and C. ulmi (Buism.) C. Moreau.The following new species are described by the author: C. acericola, C. allantospora, C. angusticollis, C. capitata, C. crassivaginata, C. dolominuta, C. magnifica, C. ochracea, C. pallida, C. spinulosa, and C. stenospora.
Physaria didymocarpa, P. brassicoides, and P. floribunda (Cruciferae) and their close relatives
Authors: Mulligan Gerald A.
Published: August 2008

Chromosome numbers are reported for three species of Physaria (Nuttall) Gray: P. didymocarpa (Hooker) Gray, 2n = 8, 16, and 24; P. brassicoides Rydberg, 2n = 8; P. floribunda Rydberg, 2n = 8, 10, 16, and 24. It is concluded that these three species and seven species treated previously form a natural group of plants that differ from other species of Physaria. Although 6 of these 10 species have two or more chromosome numbers, there are no correlations between plant morphology and the different intraspecific chromosome numbers. Analysis of karyotypes and meiotic behavior indicate that these species are remarkably similar chromosomally.
Inhibition of growth of blue stain fungi by wood extractives
Authors: Shrimpton D. M. , Whitney H. S.
Published: August 2008

Resistance by lodgepole pine to invasion by blue stain fungi is effected by an initial flow of oleoresin followed by a gradual impregnation with resinous substances of the tissues adjacent to the wound. The addition of such resinous sapwood to growth media caused inhibition of growth whereas non-resinous sapwood enhanced growth; however, extracts from both resinous and nonresinous sapwood caused inhibition of blue stain fungi. Volatile components in the extracts were responsible for this inhibition.
Cytological studies of Chaetomium cochliodes
Authors: Brewer D. , Duncan J. M.
Published: August 2008

A culture of Chaetomium cochliodes, HLX 440-1, is homothallic. The vegetative hyphal cells are multinucleate and the cells of the ascogenous hyphae are predominantly uninucleate. There is no true crozier stage in the development of the asci from the ascogenous hyphae, though a structure reminiscent of a crozier is formed. The ascogenous cell from which the ascus develops is initially uninucleate.
The appressoria of Colletotrichum graminicola and C. falcatum
Authors: Sutton B. C.
Published: August 2008

Monoconidial isolates of Colletotrichum graminicola from sorghum and maize and C. falcatum from sugarcane are separated into three groups on the basis of qualitative and quantitative differences between appressoria produced from vegetative mycelia.
Some Gymnoascaceae
Authors: Hughes S. J.
Published: August 2008

Type or presumed type collections of the type species of Myxotrichum Kunze (≡ Oncidium T. F. L. Nees, Actinospira Corda), Campsotrichwn [Ehrenb.] Pers. and Oncocladium Wallr. have been examined. Campsotrichum bicolor [Ehrenb.] Pers. is congeneric with Myxotrichum chartarum (T. F. L. Nees) Kunze and as M. bicolor ([Ehrenb.] Pers.) Fries provides an earlier name for M. poluninii Apinis. Oncocladium flavum Wallr. is based upon a conidial state of Actinodendron verticillatum (A. L. Smith) Orr and Kuehn, and Trickoderma vulpinum Fuckel is a later synonym of Arachniotus lanatus (Wallr.) Apinis. A brief history of the names Campsotrichum, Oncidium, Myxotrichum, and Actinospira is given and the confusion in Fries's synonymy of M. chartarum is partly explained.
Morphology and anatomy of Ophioglossum reticulatum
Authors: Sen U.
Published: August 2008

The anatomy and morphology of Ophioglossum reticulatum L., the specific validity of which has been in dispute, is described in detail for the first time. Important diagnostic features of the species are the presence of a cauline stele in the basal part of the stem, while in the upper part it is impossible to distinguish the cauline from the foliar strands. A single leaf trace is always found in both young and adult plants. The roots are usually monarch or less frequently diarch. The muri on the exine of the spore form a continuous reticulum and are of uniform height. The morphological nature of the fertile spike is reinterpreted. Relationship to other ferns is discussed.
Conidium ontogeny in hyphomycetes. The imperfect state of Monascus rubber and its meristem arthrospores
Authors: Cole G. T. , Kendrick W. B.
Published: August 2008

Comparative developmental studies using time-lapse photomicrography showed the characteristic conidial states of Monascus ruber van Tieghem and Backusia terricola Thirum., Whiteh., and Mathur to produce a previously undescribed type of meristem arthrospore. The two fungi are apparently conspecific, and B. terricola is placed in synonymy with M. ruber. No suitable generic name exists for the conidial state of M. ruber, and Basipetospora gen. nov. is erected to accommodate it.
A novel inflorescence in Vaccinium macrocarpon Cv. Beaver
Authors: Warrington P. , Eaton G. W.
Published: August 2008

Cranberries of Cv. Beaver have been observed to flower in September and October at Vancouver, British Columbia. The flowering uprights all showed umbrella bloom while the flowering runners bore terminal racemes. This behavior is contrary to reported photoperiodic and chilling requirements of cranberries. Mixed buds of the cranberry overwinter in a far more advanced state at Vancouver than has been previously reported.
Relation between freezing temperature and length of conifer needles
Authors: Kaku Shosuke , Salt R.W.
Published: August 2008

The relationships between freezing temperature (or supercooling) and length, weight, and water content of Pinus and Cedrus needles were investigated. Freezing temperature was an increasing function of each of these three variables. When Pinus needles were cut proximally to uniform length (50 mm), supercooling was unaffected by either weight or water content. Thus, ice nucleation temperature was an increasing function of the length of needles, or, more precisely, of the length of the stele, or, still more precisely, of the number of water-conducting capillary units contributing to that length, but ultimately of the number and quality of favorable nucleation sites contained therein. It is suggested that nucleation takes place at sites associated with the cell walls and not on nucleators suspended in the water.
Some observations on the fine structure of the marine brown alga Phaeostrophion irregulare
Authors: Bourne Victor L. , Cole Kathleen
Published: August 2008

In a fine-structure study of Phaeostrophion irregulare (Dictyosiphonales) most characteristics of the organelles and their interrelationships were found to be similar to those previously reported for other brown algae. However, there was an interesting variation regarding the pyrenoid and the nucleus–chloroplast association in the macroscopic thallus. The pyrenoid is present in the cells of the sporeling but absent from the thallus which grows directly from it. In addition, there is no evidence of any connection between the outer membranes of the nucleus and the chloroplast in the cells of the blade. The significance of these findings is discussed in relation to the phyletic importance of the pyrenoid and the possible implications of observing a limited number of heterogeneous tissue types, such as spore, sporeling, and mature thallus, in comparative studies.
Comparative behavior of the oospores and oogonia of Phytophthora citricola during germination on an artificial medium
Authors: Henry A. W. , Stelfox D.
Published: August 2008

Oospores and oogonia of Phytophthora citricola, in the same cultures on lima bean agar under moderate light and temperature conditions, germinated promptly and well without special treatment. On this medium many oospores apparently did not develop early dormancy. Most oospores germinated by one or a few straight germ tubes each bearing a sporangium which frequently proliferated, whereas most oogonia developed several often-branched tubes which infrequently terminated in sporangia.
Host range studies of oat blue dwarf virus
Authors: Westdal P. H.
Published: August 2008

Eighteen of 67 species of plants, in 7 of 14 families tested, were hosts of oat blue dwarf virus (OBDV) transmitted by the aster leaf hopper, Macrosteles fascifrons (Stal). Barley, oats, wild oats, flax, flowering flax spinach, chrysanthemum, chickweed, and stinkweed developed symptoms of the disease, whereas wheat rye, rape, endive, dill, carrot, bachelor's button, gaillardia, and wild mustard were symptomless hosts; OBDV was transmitted from these species to flax, which was used as an indicator host. The most consistent and characteristic symptom of the disease was enations, associated with veins, on the abaxial surface of the leaves.
The fine structure of the embryo of Lactuca sativa. I. Dry embryo
Authors: Paulson Ronald E. , Srivastava Lalit M.
Published: August 2008

Dry embryos of Lactuca sativa L. var. Grand Rapids were studied by improved techniques of light and electron microscopy. Cells of the dry embryo are filled with reserve proteins and lipids; the latter are preserved in the processed material only if the material is fixed in osmium tetroxide at some stage before dehydration and embedment. Nuclei, mitochondria, ribosomes, and some membranes show the least modifications in the dry state; other organelles are poorly defined and some may be absent. The best definition of organelles and membrane systems is found in the root apical cells, least in the cortical cells of the hypocotyl and mesophyll cells of the cotyledons.
The ecology of fungi infecting untreated sapwood of Pinus radiata
Authors: Butcher John A.
Published: August 2008

The succession of fungi colonizing untreated stakes of Pinus radiata sapwood was followed in aboveground, groundline, and belowground zones. The course and speed of the succession in these zones was influenced both by the source of infection and the moisture content of the wood. Aboveground moisture content of the stakes limited development, and colonization by airborne fungi (blue-stain fungi to molds) did not proceed to the stage where decay fungi became established. At groundline and below where the succession of organisms (primary molds to soft-rot fungi to secondary molds and basidiomycetes) was complete, moisture content was more favorable for fungal growth. The succession proceeded more slowly belowground than at groundline because of (1) higher moisture content of the wood and (2) colonization being restricted to soil-borne fungi. Relative frequencies of fungi in each zone are tabulated and discussed. Decay capability tests were made to aid in establishing the role of soft rot and basidiomycetous fungi. The basidiomycetes encountered were not those usually isolated from posts of P. radiata in an advanced state of decay. Comparative studies of the effect of temperature and pH on the growth rate of the various fungi isolated were of little value in explaining the broad bases for the successional trends. Some basic problems remaining in ecological studies of wood-inhabiting fungi are discussed.
Normal polarity magnetosubchrons in 24r and the age of the Paleocene–Eocene boundary
Authors: Lerbekmo J. F. , Heaman L. M. , Baadsgaard H. , Muehlenbachs K. , Evans M. E. , Sweet A. R.
Published: August 2008

A late Paleocene to early Eocene sequence of flat-lying continental strata occurs in an area known as Obed Mountain, west-central Alberta. The upper 110 m consist of interbedded fluvial channel sandstones and overbank mudrocks containing five back swamp coal seams. Two coreholes, 3.5 km apart, that extend through the entire coal zone were sampled for magnetostratigraphy and 13C isotope analysis. Bentonites in the No. 1 (lowest) and No. 5 coal seams and a tuff in the No. 3 coal seam were sampled for U–Pb and (or) Rb–Sr dating of zircon and biotite, respectively. Magnetostratigraphic analysis of 520 samples identified the younger part of chron 25r, the whole of chron 25n and the older half of chron 24r. We find six normal polarity subzones in this part of chron 24r, which we correlate to tiny wiggles 6 to11 in marine magnetic profiles. Carbon isotope analysis of 14 samples from two cores revealed a negative shift of about 2‰ peaking near the base of 24r.8r. We interpret this as the carbon isotope excursion (CIE), the base of which is now accepted as defining the Paleocene–Eocene boundary. The thickness of the CIE in the Obed Mountain section implies that it lasted between 210 000 and 254 000 years. Radiometric dates of 58.4 ± 0.2, 57.7 ± 0.3, and 56.9 ± 0.8 Ma are obtained for the No. 1, No. 3, and No. 5 coals, respectively. Combining these with magnetostratigraphy and cyclostratigraphy yields an age of 57.1 ± 0.1 Ma for the Paleocene–Eocene boundary.
Mortality of Starry Flounders (Platichthys stellatus) with Skin Tumors
Authors: Campana Steven E.
Published: August 2008

The incidence of skin tumors among starry flounders (Platichthys stellatus) in Bellingham Bay, Washington, varied both spatially and temporally. Incidence was 37% in the young-of-the-year inshore fish, declining to near-zero values by age II. My results indicate that tumor regression and spatial segregation of tumorous fish were not responsible for the decline, but that tumorous individuals had a high mortality rate relative to normal conspecifics. Selection against tumorous individuals was indicated by a sharp decline in tumor incidence in 1-yr-old fish at the same time as mean tumor number per fish declined and tumorous fish became significantly smaller than their normal counterparts. There were no differences in susceptibility to stress between normal and tumorous fish until age I; age I tumorous fish had a higher mortality rate under stressful conditions. The flounder skin tumors are lethal to a large proportion of each year-class, and therefore represent one of the largest known sources of repetitive, disease-induced mortality of fishes.Key words: starry flounder, skin tumor, X cell, mortality
Optimal Fisheries Investment under Uncertainty
Authors: Charles Anthony T.
Published: August 2008

A full analysis of optimal fisheries investment strategies must take into account high levels of uncertainty in future fishery returns, as well as irreversibility of investment in specialized, nonmalleable fishing fleets. A stochastic optimization model is analyzed using dynamic programming to determine optimal policy functions for both fleet investment and fish stock management within an uncertain environment. The resulting policies are qualitatively similar to those found in the corresponding deterministic case, but quantitative differences can be substantial. Simulation results show that optimal fleet capacity should be expected to fluctuate over a fairly wide range, induced by stochastic variations in the biomass. However, the performance of a linear-cost risk-neutral fishery is fairly insensitive to variations in investment and escapement policies around their optimum levels, so that economic optimization is "forgiving" within this context. A framework of balancing upside and downside investment risks is used here to explain the roles of several fishery parameters in relation to optimal investment under uncertainty. In particular, the intrinsic growth rate of the resource and the ratio of unit capital costs to unit operating costs are found to be key parameters in determining whether investment should be higher or lower under uncertainty.
Influence of Deteriorating Water Quality on Growth and Development of Chum Salmon (Oncorhynchus keta) Larvae in a Japanese-Style Keeper Channel
Authors: Bams R. A. , Lam C. N. H.
Published: August 2008

Chum salmon (Oncorhynchus keta) larvae were incubated in gravel-filled cages placed in two experimental Japanese-style keeper channels having 40 and 80 L/min total flow, at three successive locations having 0, 46 000, and 92 000 eggs (or alevins) upstream. Minimum dissolved oxygen was 6.21 mg/L, maximum un-ionized ammonia was 0.18 μg/L, pH varied from 7.18 to 6.83, and temperature ranged from 7.8 to 8.2 °C. Preemergent fry showed small but significant decreases in mean fork length, with increasing distance along both channels 50 d after hatching. Weights decreased similarly but nonsignificantly in both channels. Stage of development (expressed as KD-index) was constant in all locations except the bottom location of the low-flow channel, which showed a significant delay. Survival was uniformly high with no differential mortality among locations or flow rates. We conclude that deteriorating water quality measurably reduced larval development rate, growth rate, and yolk-conversion efficiency. Main effective factor was dissolved oxygen. Standard channel loading and flow criteria are adequate for short incubation channels only.
Similarities in Avoidance Temperatures of Freshwater Fishes
Authors: Mathur Dilip , Schutsky Robert M. , Purdy Jr. Edmund J. , Silver Carl A.
Published: August 2008

A statistical analysis of new and published data revealed strong geographic similarities in laboratory-determined avoidance temperatures of several freshwater fishes. Validated regression models developed from our laboratory data predicted avoidance temperatures, within specified variation, of species from other areas. Four cyprinids, two ictalurids, seven centrarchids, and two percids were tested. Species within each family showed similar avoidance temperatures. An exception was white crappie, Pomoxis annularis, which avoided lower temperatures than other centrarchids. Acclimation temperature was the most significant predictor variable. No significant differences of practical value were observed in avoidance temperatures between rising and falling field temperature. Our analysis provides an impetus to minimize site-specific laboratory studies of temperature avoidance for individual species and provides an objective method for literature data comparisons.
A Stochastic Age-Structured Population Model of Striped Bass (Morone saxatilis) in the Potomac River
Authors: Cohen Joel E. , Christensen Sigurd W. , Goodyear C. Phillip
Published: August 2008

Deterministic age-structured models of fish populations neglect apparently stochastic fluctuations in the catch per unit effort of yearlings and of adult fish. We describe a model of an age-structured population in which the survival of eggs to yearlings fluctuates randomly, but all other age-specific rates of survival and of egg-laying are constant. For such a stochastic model, two measures of the long-term population growth rate are the average growth rate of the population size and the growth rate of the average population size. We compute both measures analytically for a simplified model representing only eggs and reproductive adults. For a model of the striped bass (Morone saxatilis) population spawning in the Potomac River, we compute both point and interval estimates of the growth rate of the average population size. We illustrate some statistical tests of the correctness of our stochastic model.
The English–Wabigoon River System: II. Suppression of Mercury and Selenium Bioaccumulation by Suspended and Bottom Sediments
Authors: Rudd John W. M. , Turner Michael A.
Published: August 2008

Bioaccumulation of 203Hg and 75Se by several members of the food chain, including fish, was followed in large in situ enclosures in the presence and absence of organic-poor sediment. When the sediment was absent, 203Hg was bioaccumulated 8- to 16-fold faster than when it was either suspended in the water or present on the bottom of the enclosures. Mercury-contaminated and uncontaminated sediments were equally effective at reducing the rate of radiolabeled mercury bioaccumulation, apparently by binding the mercury to fine particulates making it less available for methylation and/or bioaccumulation. Based on these results, a mercury ameliorating procedure involving semicontinuous resuspension of organic-poor sediments with downstream deposition onto surface sediments is suggested. The presence of sediments, in the water or on the bottom of enclosures, also reduced radiolabeled selenium bioaccumulation. The degree of inhibition (2- to 10-fold) may have been related to the concentration of organic material in the predominantly inorganic sediments. Implications of this research with respect to mercury–selenium interactions in aquatic ecosystems are discussed.
Dispersal of American Lobsters, Homarus americanus, Tagged Off Southern Nova Scotia
Authors: Campbell Alan
Published: August 2008

Of the 5281 American lobsters (Homarus americanus) tagged and released off McNutt Island, South Nova Scotia, during 1983–87, 15.8% were captured within 3 yr of release. Although most immature (99%) and mature (86%) lobsters were caught < 18.5 km from release, mature lobsters moved a greater mean distance (25.8 km) than immature lobsters (3.6 km). Of the lobsters that moved > 30 km eight moved south to the continental slope near Browns Bank and 11 moved west of Cape Sable to the inshore areas of southwestern Nova Scotia, the midshore area of German Bank and offshore to Browns Bank and Georges Bank. This and other studies of tagged lobsters indicate that there is some movement of lobsters east and west of the Cape Sable area, the southern tip of Nova Scotia, suggesting some mixing between lobster stocks off eastern Nova Scotia and southwestern Nova Scotia. The long distance movement and mixing of mature lobsters suggests that attempts to use tagging information in locating biological boundaries between lobster stocks in the Gulf of Maine, adjoining Continental Shelf, Scotian Shelf and inshore areas of southwestern Nova Scotia and southern end of eastern Nova Scotia may be a difficult task.
Copper and nickel uptake and accumulation, and their effects on redox and electrical potentials of hepatopancreatic cells of Oniscus asellus Linnaeus (Porcellionidae, Isopoda)
Authors: Alikhan M. A. , Storch V.
Published: August 2008

Highest tissue Cu concentrations (1728 μg∙g dry weight−1) in whole Oniscus asellus, reared for 7 days on carrot powder containing 50 μg Cu∙g dry weight−1, 10 μg Ni∙g dry weight−1, or a mixture of 50 μg Cu and 10 μg Ni∙g dry weight−1, were observed in isopods on 50 μg Cu∙g dry weight−1, and lowest (917 μg∙g dry weight−1) in those on 10 μg Ni∙g dry weight−1. Highest Ni concentrations (277 and 272 μg∙g dry weight−1) were present in isopods fed on a mixture of 50 μg Cu and 10 μg Ni∙g dry weight−1 and 10 μg Ni∙g dry weight−1, respectively, and lowest (201 μg∙g dry weight−1) in those on 50 μg Cu∙g dry weight−1. Of the total body-tissue Cu, 8–66% was contained in membrane-bound vesicles of hepatopancreatic S-cells, and 73–89% of Ni was present inside the lumen and within S-cells of the hepatopancreas. The presence of Ni in the diet appeared to adversely affect the absorption and hepatopancreatic storage of Cu. Copper slightly enhanced, and nickel drastically reduced, the hepatopancreatic redox (= catalytic activity) and cell-membrane surface potentials. The significance of these findings is discussed.