bluuebunny/crossref_metadata_2025 huggingface dataset:
COCHLIOBOLUS SATIVUS: V. HETEROKARYOSIS AND PARASEXUALITY
Authors: Tinline R. D.
Published: August 2008

Multiply marked strains of Cochliobolus sativus were used to synthesize heterokaryons. The heterokaryons apparently were formed by hyphal anastomosis and nuclear migration. Some conidia (not more than 6%) from heterokaryotic cultures perpetuated the heterokaryons. Probably this low frequency of heterokaryotic conidia was due to a non-random distribution of nuclei in the conidia. Variation in strains due to heterokaryosis may be reduced by the isolation of single spores or hyphal tips in several successive generations. Heterozygous diploids were selected from two heterokaryons on the basis of their phenotypic differences: heterokaryons grew slowly and intermittently; diploids grew rapidly and uniformly. Heterokaryons but not diploids readily dissociated into their components. Diploid spores were consistently larger but not twice as large in volume as haploid ones.Dominant–recessive relationships were expressed in heterokaryons and diploids; white was recessive to tan spore color; nutritional requirements were recessive to the wild type alleles; and resistance to anisomycin was semidominant. Segregants were obtained from a diploid strain by various techniques. Equal numbers of heterozygous and "presumptive" homozygous segregants were found and most of them were recombinants. A parasexual cycle therefore occurs in this heterothallic ascomycete.
STUDIES OF COPROPHILOUS ASCOMYCETES: VIII. NEW SPECIES OF PODOSPORA
Authors: Cain Roy F.
Published: August 2008

Podospora is the valid genus for a group of coprophilous species in which the ascospores have appendages but no gelatinous sheaths. The type species is P. fimicola Cesati. The following new species found on dung are described and illustrated: P. absimilis, Tautira; P. brasiliensis, Brazil; P. castorinospora, Panama Canal Zone; P. comatospora, Venezuela, Tautira, and Moorea; P. curvuloides, Brazil; P. inflatula, Tautira and Brazil; P. nannopodalis, New York; P. ostlingospora, Mexico; P. papilliformis, Venezuela and Mexico; P. prethopodalis, Tautira, Moorea, and Paea. The following are transferred from Pleurage as new combinations in Podospora: P. adelura (Griff.), P. anomala (Griff.), P. arizonensis (Griff.), P. collapsa (Griff.), P. gwynne-vaughaniae (Page), P. heterochaeta (Griff.), P. hyalopilosa (Stratton), P. immersa (Stratton), P. kansensis (Griff.), P. longicaudata (Griff.), P. taenioides (Griff.) and P. unicaudata (C. & M. Moreau). The following are transferred from Sordaria as new combinations in Podospora: P. araneosa (Cain), P. cervina (Cain), P. coronifera (Grove), P. curvispora (Cain), P. dubia (Hansen), P. eminens (Cain), P. fimbriate, (Bayer), P. globosa (Massee & Salmon), P. glutinans (Cain), P. inaequalis (Cain), P. inaequilateralis (Cain), P. kilimandscharica (A. Schmidt), P. leporina (Cain), P. linguiformis (Cain), P. ontariensis (Cain), P. perplexens (Cain), P. pilosa (Mouton), P. piriformis (Bayer), P. tetraspora (Winter). The following are transferred from Philocopra as new combinations in Podospora: P. coeruleotecta (Rehm) and P. millespora (A. Schmidt).
UROMYCES STRIATUS SCHROET. IN ONTARIO
Authors: Parmelee J. A.
Published: August 2008

Large stands of Euphorbia cyparissias L. in Ontario supporting aecia of Uromyces striatus Schroet. presented an opportunity for the author to study this stage of the rust hitherto little known in North America since its discovery here in 1947. The mycelium was found to be systemic and perennial and the aeciospores capable of infecting many species of Medicago and some yellow-flowered species of Trifolium. Pisum sativum was just slightly susceptible. Both diploid and tetraploid nuclear conditions of E. cyparissias have been found rusted and E. esula, long suspected as a host in Europe, has also been found rusted and the connection to Leguminosae shown by inoculation. Specimens resulting from inoculations (109) and from field collections from Canada (33), United States (18), and Europe (13) were identical in spore morphology. This, plus susceptibility of Leguminosae from Europe to the inoculum from Ontario, supports the suggestion that the rust was introduced to North America from Europe. It is further suggested that U. striatus was introduced on either or both alternate hosts independently. The common occurrence of telia is recorded and the fungus is redescribed.
THE PHYSIOLOGY OF HOST–PARASITE RELATIONS: X. THE METABOLISM OF INDOLEACETIC ACID-1-C14BY WHEAT AND OAT COLEOPTILE SECTIONS, UNINFECTED AND RUSTED WHEAT LEAVES AND UREDOSPORES OF WHEAT STEM RUST
Authors: Srivastava B. I. Sahai , Shaw Michael , Woods R. J.
Published: August 2008

Coleoptiles of Little Club wheat and Brighton oats, uninfected and rusted leaves of Little Club and Khapli wheats and uredospores of stem rust were incubated with 10 or 100 parts per million of indoleacetate-C14OOK (IAA) in distilled water in darkness. The metabolic products formed were extracted by boiling the incubation medium. This was then partitioned with ether and the aqueous and ether fractions were analyzed by paper chromatography. In the coleoptiles and uninfected and rusted wheat leaves 8–14 different Ehrlich- or Salkowski-positive radioactive products of IAA metabolism were detected. These were not found when the plant material was incubated with water alone. One ether-soluble compound, and four ether-insoluble compounds from wheat coleoptiles had ultraviolet spectra of the indole type and were found to be active in the Avena straight growth test. IAA and its ether-soluble products disappeared more rapidly from uninfected than from rust-infected Little Club wheat leaves. Four water-soluble, radioactive products were found in uninfected leaves but only two in rusted leaves. A substance tentatively identified as indolecarboxylic acid (ICA) was not found in Little Club wheat leaves until 16 days after rust infection, but was present in both uninfected and infected leaves of the resistant species, Khapli. Uredospores apparently converted IAA only to nonradioactive decarboxylation products, tentatively identified as ICA and indolealdehyde. The results are discussed and attention is drawn to the importance of ether-insoluble products of IAA metabolism.
SOME WEED HOSTS OF THE NORTHERN ROOT-KNOT NEMATODE, MELOIDOGYNE HAPLA CHITWOOD, 1949, IN ONTARIO
Authors: Townshend J. L. , Davidson T. R.
Published: August 2008

Forty-one species of weeds were found to be hosts of the northern root-knot nematode, Meloidogyne hapla Chitwood, 1949, in Ontario. Variation in the size of the small galls caused by the nematode was correlated with the thickness of the root of the host. Abnormally large galls found on a few species of weeds were due to multiple infections by the nematode.
SUPERNUMERARY CHROMOSOMES IN DIPLOID AND TETRAPLOID FORMS OF CRESTED WHEATGRASS
Authors: Baenziger H.
Published: August 2008

Supernumerary chromosomes were present in two diploid introductions of crested wheatgrass but absent in the diploid variety Fairway. In five tetraploid populations, they were present in 36.9 to 88.5% of the plants.Diploid plants contained supernumerary chromosomes in pollen mother cells, in primary roots, and in stem tissues, but not in adventitious roots. Supernumeraries in crested wheatgrass were usually smaller than basic chromosomes and they were not heterochromatic. There was good pairing between supernumeraries but not between supernumerary and A-chromosomes. Transmission of supernumeraries through the egg generally occurred in haploid numbers. In pollen, directed non-disjunction of supernumeraries towards the gametes took place with an average frequency of approximately 70%. The degree of transmission depended to some extent on the genotype of the parent and on the numbers of supernumeraries involved. Elimination of supernumeraries from reproductive tissues was generally low but became more pronounced at higher frequencies.
UREIDE SYNTHESIS AND TRANSLOCATION IN SILVER MAPLE SEEDLINGS
Authors: Barnes Robert L.
Published: August 2008

The synthesis of ureides was studied in root, stem, and leaf tissues, as well as in intact seedlings, of silver maple (Acer saccharinum L.) using radiotracer techniques. Ureide synthesis was demonstrated from carbon-14 labeled adenine, glycine, formate, urea, and bicarbonate. Ureide synthesis from adenine apparently followed the degradative pathways previously known in animal tissues. Synthesis of ureides from glycine, formate, urea, and bicarbonate appeared to be via a purine precursor, probably inosinic acid or a closely related compound. The experimental methods were not discriminating enough to demonstrate whether ureides are normally synthesized in the roots and translocated to the tops of maple seedlings.
BRYOPHYTES OF THE CYPRESS HILLS PROVINCIAL PARKS, ALBERTA AND SASKATCHEWAN
Authors: Bird C. D.
Published: August 2008

One hundred mosses and seven liverworts are reported from the Cypress Hills of southwestern Alberta and southeastern Saskatchewan. Included are 11 bryophytes not previously reported from Saskatchewan and 6 new to Alberta. Of special interest was the discovery of Scapania carinthiaca, known previously from two North American stations and a few in Europe and Siberia. Also interesting was the collection of Dicranum drummondii and Mnium drummondii, both of which are seldom encountered and are restricted to a central North American distribution pattern. Chromosome counts were made from material of Atrichum undulatum var. altecristatum (n = 7), Atrichum selwynii (n = 7), and Plagiothecium turfaceum (n = 11). The ecology and elements of the area are discussed. A montane element of 9.1% was found to exist in the moss flora.
NEW SPECIES AND NEW RECORDS OF OIDIODENDRON
Authors: Barron G. L.
Published: August 2008

Four new species of Oidiodendron, viz. O. truncatum, O. maius, O. citrinum, and O. echinulatum, are described from soil. One new combination, O. cerealis (Thum.) Barron, is proposed and an emended description of O. flavum Szilvinyi presented. O. fuscum Robak is considered to be conspecific with the prior O. tenuissimum (Peck) Hughes.
BLUE STAIN FUNGI IN LODGEPOLE PINE (PINUS CONTORTA DOUGL. VAR. LATIFOLIA ENGELM.) INFESTED BY THE MOUNTAIN PINE BEETLE (DENDROCTONUS MONTICOLAE HOPK.)
Authors: Robinson Robena C.
Published: August 2008

A complex of fungi was isolated from lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) at various stages of mountain pine beetle (Dendroctonus monticolae Hopk.) attack. Ceratocystis montia Rumb., Leptographium sp., Pichia pini (Hoist) Phaff, Hansenula holstii Wickerham, Hansenula capsulata Wickerham, and some unnamed yeasts were isolated from beetles, fresh galleries, and blue-stained sapwood. Perithecia of C. montia, Ceratocystis minor (Hedgc.) Hunt, Ceratocystis minuta (Siem.) Hunt, Ceratocystis sp., and Europhium sp. were found on the bark and sapwood of dead, blue-stained trees. Beetles are conclusively shown to be vectors of blue stain fungi. The known ranges of C. montia and P. pini are extended by this study and a possible succession of organisms associated with the development of beetle infestation is discussed.
PATHOGENIC VARIATION IN MYCOSPHAERELLA FRAGARIAE
Authors: Bolton A.T.
Published: August 2008

Forty-nine cultural types of Mycosphaerella fragariae (Tul.) Lindau are placed in six groups according to their virulence on nine strawberry varieties varying in field resistance. It is suggested that each of the six virulence groups represents a physiologic race. It is also suggested that the variation in leaf spot resistance in different areas is due to the presence of these races, and that they must be considered when breeding for resistance.
DRECHSLERA ITO
Authors: Shoemaker R. A.
Published: August 2008

This taxonomic study of the hyphomycete genus Drechslera is based on type specimens, and on fresh collections and herbarium specimens principally from North America. Characters of conidia and conidiophores, and the growth characteristics of the species in artificial culture, are described and illustrated. Two keys to species are included: one based on characters of conidia and conidiophores; the second based on growth characteristics on sucrose proline agar. Fifteen species, one composed of two formae speciales, are accepted. Their names and some of the well-known synonyms are: D. avenacea (Curtis ex Cooke) Shoem. (= Helminthosporium, avenae Eidam); D. bromi (Died.) Shoem.; D. catenaria (Drechs.) Ito; D. dactylidis n. sp.; D. dictyoides (Drechs.) Shoem. f. sp. dictyoides; D. dictyoides f. sp. perenne (Braverman & Graham) n. comb.; D. erythrospila (Drechs.) Shoem.; D. fugax (Wallr.) Shoem. in Hughes (= H. stenacrum Drechs.); D. gigantea (Heald & Wolf) Ito; D. graminea (Rab. ex Schlecht.) Shoem.; D. phlei (Graham) Shoem.; D. poae (Baudys) n. comb. (= H. vagans Drechs.); D. siccans (Drechs.) Shoem.; D. teres (Sacc.) Shoem.; D. tritici-repentis (Died.) Shoem. (= Drechslera tritici-vulgaris (Nisikado) Ito); and D. tuberosa (Atk.) Shoem. (= H. secalis Whitehead & Dickson, = H. japonicum Ito & Kurib., = H. fragosoi Bubak). Also included are the perfect states of six species: Pyrenophora chaetomioides Speg. (st. conid. D. avenacea); P. bromi (Died.) Drechs. (st. conid. D. bromi); P. teres Drechs. (st. conid. D. teres); P. tritici-repentis (Died.) Drechs. (st. conid. D. tritici-repentis); P. japonica Ito & Kurib. in Ito (st. conid. D. tuberosa), and the perfect state of D. dactylidis.
STUDIES ON RUBUS VIRUS DISEASES IN BRITISH COLUMBIA: IX. RINGSPOT DISEASE OF RED RASPBERRY
Authors: Stace-Smith Richard
Published: August 2008

A virus disease of red raspberry that has been known in Oregon and Washington for several years was observed for the first time in British Columbia in 1961. The disease is characterized by chlorotic blotches, ringspot, or oak leaf markings, or a net-like chlorosis along the smaller veins of the leaves on the young canes. The virus nature of the disease was demonstrated by mechanical transmission from raspberry leaves to herbaceous plants. From physical properties and symptoms on a range of herbaceous hosts and peach seedlings, the virus was considered to be related to tomato ringspot virus. This relationship was confirmed by comparative host reactions and cross protection studies with known strains of tomato ringspot virus.
THE GENUS SCIRPUS LINN.: SOME NORTH AMERICAN APHYLLOID SPECIES
Authors: Koyama Tetsuo
Published: August 2008

Some North American aphylloid species of Scirpus are discussed in detail with particular emphasis on Asiatic–American relationships. Beetle, in 1947, recognized 27 species in this group; 15 of his species examined in the present treatment are reduced to 8. The following new combinations are proposed: S. juncoides var. Williamsii, S. Smithii var. leiocarpus, S. supinus var. saximontanus, S. lacustris ssp. validus, S. lacustris ssp. validus var. luxurians, S. subterminalis var. cylindricus, S. subterminalis ssp. nipponicus, and S. maritimus f. cymosus.
THE PHYSIOLOGY OF HOST–PARASITE RELATIONS: XI. THE EFFECT OF STEM RUST ON THE PHOSPHATE FRACTIONS IN WHEAT LEAVES
Authors: Mukherjee1 K. L. , Shaw Michael
Published: August 2008

Inorganic, organic, and various organic phosphate fractions were determined in uninfected and infected first seedling leaves of Little Club wheat at various stages between 6 to 18 days after incubation with Puccinia graminis tritici Erikss. and Henn. (Race 15B). Inorganic (Pi), organic (Po), and total P per unit fresh weight increased as uninfected leaves aged and the levels of Pi were much more readily altered by changes in nutritional status and environmental conditions than the levels of Po. Infection increased total P and the highest concentrations occurred at the loci of rust pustules. Since the concentration of P was lower in uninfected portions of infected leaves than in comparable parts of uninfected leaves or in rust pustules, it appeared that P was transported into the pustules from uninfected parts of the leaf. Both Pi and Po were increased by infection, but the Pi/Po ratio was lowered. Acid-soluble bound P, easily hydrolyzable P, lipid P, RNA-P, and residual organic P were all increased by infection.When leaf pieces were infiltrated with and then floated on 10−4 M 2,4-dinitrophenol for 24 hours, the levels of all organic phosphate fractions were lowered and Pi was increased, both in uninfected and infected leaves. Dinitrophenol raised the Pi/Po ratio about 30% in uninfected and about 100% in infected leaves.The results militate against the view that the increase in respiration rate caused by infection is due to the uncoupling of oxidative phosphorylation.
STUDIES IN WOOD-INHABITING HYMENOMYCETES: V. THE GENUS PYCNOPORUS KARST.
Authors: Nobles Mildred K. , Frew Barbara P.
Published: August 2008

Genetical and morphological evidence supports the validity of three species of red polypores: Pycnoporus cinnabarinus (Jacq. ex Fr.) Karst., which occurs in the North Temperate zone; P. coccineus (Fr.) Bond. & Sing., which occurs in the South Temperate zone and in countries bordering on the Indian and Pacific Oceans; and P. sanguineus (L. ex Fr.) Murr. in tropical and subtropical regions of the Northern and Southern Hemispheres. Descriptions of carpophores and cultures are given for each species along with a revised description of the genus Pycnoporus Karst.
DORMANCY AND GERMINATION OF SEEDS OF SILVERBERRY (ELAEAGNUS COMMUTATA BERNH.)
Authors: Corns Wm. G. , Schraa R. J.
Published: August 2008

Silverberry (Elaeagnus commutata Bernh.) is of some importance as an ornamental shrub and in certain areas is a rangeland weed. Various germination tests over a 2-year period showed that unstratified seeds of this species, within intact endocarps, germinated 0 to 20% in 10 days, and 0 to 45% within 20 days, on moist filter paper in Petri dishes in the dark at 20 °C. After stratification of such seed in moist sand at 5 °C, for periods of 40 to 110 days, the germination percentages ranged from about 23% to 75% respectively. Removal of the endocarps, however, from unstratified seeds resulted in 85 to 100% germination within 10 days. A water-soluble extract from the endocarps retarded growth of wheat seedlings and of seedlings from naked silverberry seeds but did not reduce percentage germination. Self-controlled embryo dormancy is apparently not a major factor causing delayed germination of the silverberry.Supplementary tests involving heat treatments, or soaking of the unstratified fruits in gibberellin or KNO3 solutions, were without effect on germination of silverberry seed from within its endocarp.
DENDROGRAPH PATTERNS IN DECAPITATED TREES: PRELIMINARY OBSERVATIONS
Authors: Greenidge K. N. H.
Published: August 2008

Dendrographs attached to the lower boles of large trees of several species indicated little change in diametral fluctuation patterns following decapitation or severe mechanical interruption of conducting tissues. Treated and undisturbed stems of a particular species, investigated concurrently, manifested striking similarities in the amount, trend, and duration of diameter shrinkage. The results of these experiments, in company with others dealing with continued moisture movement in experimentally treated trees, jointly suggest that the water-conducting system of large wood stems is one of great coherency and stability.
STUDIES ON THE NATURE OF RESISTANCE IN TOMATO TO CLADOSPORIUM FULVUM COOKE
Authors: Bailey D. L. , Lowther Ruth L.
Published: August 2008

The sugar and amino acid content of six tomato varieties were compared by paper chromatographic methods. These varieties reacted to race 1 of Cladosporium fulvum Cke. as follows: Potentate, susceptible; V-121 and Stirling Castle, resistant; Vetomold, Vinequeen, and Lycopersicon pimpinellifolium (Jusl.) Mill., immune. Potentate, Vetomold, and V-121 are closely related genetically, the last two having been developed by repeated backcrossing to Potentate of immune and resistant segregates from Potentate × L. pimpinellifolium crosses. The resistance of Stirling Castle is controlled by a gene different from the gene which conditions immunity in Vetomold and one that confers resistance on V-121, while the immunity of Vinequeen stems from L. hirsutum Humb. and Bonpl.Fructose, glucose, and sucrose occurred in all varieties, but, among the three closely related ones, the consistently low level of all three in V-121 and the low fructose in Red Currant were suggestive, while Potentate and Vetomold displayed reciprocal levels of fructose and sucrose. The two resistant varieties differed in sugar content and the three immune ones were not consistent.From four sets of extracts of all six varieties, grown under conditions optimal for disease expression, 15 amino acids were identified. The relative amounts of these differed significantly in different varieties without, however, any general causal relation to resistance being evident. The consistently lower levels of one or more of aspartic acid, serine, and glutamine in V-121 may be significant in limiting the development of the fungus in this resistant variety. The immunity of Vetomold did not seem to be conditioned by the presence or absence of specific amino acids nor did the immunity of Vinequeen. When extracts of this sort were compared with extracts from plants grown under a light experience reduced sufficiently to disturb the host–parasite relations, it was evident that this treatment significantly altered both the sugar and amino acid content of the varieties in characteristic varietal patterns. This may suggest that a suitable C/N ratio is prerequisite to compatibility. The desirability of further studies is indicated.
CHANGED RESPONSE OF EXCISED TOMATO ROOTS TO PYRIDOXIN DEFICIENCY FOLLOWING PROLONGED STERILE CULTURE
Authors: Willemot Claude , Boll W. G.
Published: August 2008

A clone of excised tomato roots, selected originally for its marked requirement for vitamin B6, has been maintained in continuous culture in pyridoxin-containing medium since 1956. Growth in pyridoxin-free medium is now considerably greater than when the clone was originally isolated. A subclone of this clone was isolated in 1957 and maintained in medium in which pyridoxin was replaced with ethanolamine. This subclone does not show the change in response to pyridoxin deficiency. Because of this and other evidence it is concluded that the change occurs because of a change in the clone and is not an artefact due to faulty technique.The result is discussed in relation to (a) other reported changes in tissue cultures including the phenomenon of "adaptation" (accoutumance) to indole acetic acid, (b) the cellular control of metabolism.
CHROMOSOME NUMBERS IN 28 GRASS GENERA FROM SOUTH AMERICA
Authors: Bowden Wray M. , Senn Harold A.
Published: August 2008

The somatic (2n) chromosome numbers of more than 70 species of 28 genera of grasses from Bolivia, Argentina, Chile, and Uruguay are recorded. The chromosome numbers of about half of these species have not been reported in previous cytotaxonomic literature. The 28 genera are Agrostis, Aira, Andropogon, Apera, Arrhenatherum, Briza, Bromus, Cenchrus, Chloris, Cynodon, Danthonia, Eragrostis, Festuca, Gastridium, Koeleria, Melica, Nassella, Paspalum, Phalaris, Poa, Polypogon, Rottboellia, Schismus, Setaria, Sporobolus, Stipa, Trichachne, and Trichloris.
WARDOMYCES AND ASTEROMYCES
Authors: Hennebert Grégoire L.
Published: August 2008

Two new species, Wardomyces hughesii Hennebert and W. humicola Hennebert and Barron, are added to the genus Wardomyces Brooks and Hansford, which was described in 1923 for the single species W. anomala Brooks and Hansford. The three species, isolated from decayed wood, forest soil, greenhouse soil, or animal products, are described and illustrated.The related genus Asteromyces and the single species A. cruciatus F. and Mme Moreau are validated by the provision of Latin diagnoses and illustrated.The relationship between both genera is discussed.
A MORPHOLOGICAL STUDY OF THE RED ALGA WHIDBEYELLA CARTILAGINEA SETCHELL ET GARDNER
Authors: Scagel Robert F.
Published: August 2008

The carpogonial morphology and early stages in development of the carposporophyte of Whidbeyella cartilaginea Setchell et Gardner are described for the first time. These observations confirm the systematic position of the species in the family Chaetangiaceae and the order Nemalionales.
A GROWTH INHIBITOR FROM THE ROOTS OF CHRYSANTHEMUM MORIFOLIUM RAMAT. AND ITS INFLUENCE UPON THE GIBBERELLIC ACID RESPONSE
Authors: Ballantyne D. J.
Published: August 2008

The growth-reducing factor in old chrysanthemum soil previously reported in Ontario was found to inhibit growth by reducing number of internodes and internode length. A further effect was the reduction in number of flower buds. Gibberellic acid applications could offset growth reductions but enhanced reduction in floral number. Factors that could inhibit growth of wheat coleoptile sections could be extracted from chrysanthemum roots and buds. A methanolic root extract, after being subjected to paper chromatography with 80% isopropanol, slightly inhibited the growth of chrysanthemums. This inhibiting factor was in the same region of the chromatogram as the factor which inhibited the growth of wheat coleoptile sections. The response to the growth reducing factor is compared with that to naphthalene acetic acid.
EXPERIMENTS ON THE RELATIVE SUSCEPTIBILITY OF WEEDS TO AUXIN HERBICIDES
Authors: Hay J. R.
Published: August 2008

Sections of stems of Silene cucubalus, Galeopsis tetrahit, and Phaseolus vulgaris were cultured under sterile conditions in media containing inorganic salts, sucrose, agar, and the herbicides 2-methyl, 4-chlorophenoxyacetic acid, 2,4-dichlorophenoxyacetic acid, or 2-(2,4,5-trichlorophenoxy)propionic acid. The herbicide which gave the most effective control of a species under field conditions was also the most active in inducing root formation and proliferation on stem sections of that species. The response of the sections to these auxin herbicides diminished as the plants from which the sections were taken became more mature. The amount of herbicide recovered from treated shoots of these species was not correlated with susceptibility. It is postulated that susceptibility to these materials depends upon (i) the affinity of the species for the molecular configuration of the herbicide and (ii) the relative amount and functional importance of the susceptible tissues at the time of treatment.
STUDIES ON SUNFLOWER RUST: III. OCCURRENCE, DISTRIBUTION, AND SIGNIFICANCE OF RACES OF PUCCINIA HELIANTHI SCHW.
Authors: Sackston W. E.
Published: August 2008

Discovery of rust-resistant sunflower seedlings in 1952 made it possible to distinguish races of Puccinia helianthi Schw. occurring on cultivated sunflowers (Helianthus annuus L.). The races isolated in 1954 helped to identify two discrete factors for resistance derived from wild annual sunflowers from the Renner, Texas, area. The four races which theoretically could be distinguished with two resistance factors have all been found in Manitoba. Collections from other provinces, countries, and continents, with few exceptions were classified on the Canadian differentials as race 1. Differences among isolates of race 1 were observed on resistant derivatives of H. argophyllus T. and G. Use of the four rust races described made it possible to identify different factors for resistance in sister selections of sunflowers with identical rust reactions in the field, and to demonstrate that the original rust resistant accessions 953-88 and 953-102 each contained at least two distinct resistance factors. Use of the races has also made it possible to recognize the existence in H. argophyllus of factors for rust resistance which appear to differ from those in the Canadian differential varieties.
STUDIES ON FUSARIUM WILT OF BANANAS: VIII. DIFFERENTIATION OF CLONES BY CULTURAL INTERACTION AND VOLATILE SUBSTANCES
Authors: Stover R. H.
Published: August 2008

Cultural interaction between paired clones A and C of F. oxysporum f. cubense on peptone dextrose agar was a reliable tool for identification of these clones. Cultural interaction consisted of the formation of two bands of dense mycelial growth. The first and largest band formed in clone C colonies back of the tips of the outermost hyphae in contact with adjacent clone A colonies. A second much smaller band formed with clone C hyphae outside of and adjacent to the large band. The smaller band sometimes merged with the larger. This specific band reaction was distinct from a non-specific "interaction" occurring on rice agar. Mutants were produced by clones A and C, which reacted with the parents by the formation of a single band of raised, dense mycelia. These reactions were unstable and non-specific. Cultural interaction was erratic and often poorly defined with ropy mutants of clones A and C. Cultural interaction with clone A readily identified clone C from banana roots from areas where a locus of infection had been initiated by inoculation 3 years previously. Thus, cultural interaction was useful in "tagging" F. oxysporum f. cubense for studies with mixed indigenous soil populations of F. oxysporum.‘Odoratum’ and ‘Inodoratum’ clones (readily separated by smell on steamed rice) were subjected to gas chromatography. All 'Odoratum' cultures gave a characteristic spectrum showing qualitative and quantitative differences from the 'Inodoratum' cultivar in volatiles produced. The characteristic 'Odoratum' smell after 7 days on steamed rice was associated with a spectrum not shown by 'Inodoratum' clones.
PHYTOPLANKTON FROM SOME LAKES IN NORTHERN SASKATCHEWAN AND FROM GREAT SLAVE LAKE
Authors: Lund J. W. G.
Published: August 2008

The algae in samples of net plankton from some Canadian lakes are recorded and those of special interest discussed. The majority are supposedly well-known algae which, in fact, are either imperfectly known or the subject of such disagreements among specialists that they have been and still are described under more than one generic or specific name. This has led to misunderstandings about the type of phytoplankton present in some Canadian lakes. Judging by the present samples and the papers of the late Professor D. S. Rawson, the more oligotrophic lakes are dominated by diatoms and the more eutrophic ones by a mixture of these and Cyanophyta.
FACTORS CONTROLLING EMBRYO GROWTH AND DEVELOPMENT IN BARLEY (HORDEUM VULGARE L.)
Authors: Croix L. J. La , Naylor J. , Larter E. N.
Published: August 2008

Normal growth and development of barley proembryos occurred in excised intact florets, but not in ovaries from which lemmas and paleas were removed. The lemmas and paleas of the barley floret apparently contained a substance (referred to as "hull factor") which inhibited cell extension and stimulated cell division in the embryo. Evidence was obtained that this stimulation was not due to the provision of a simple energy source such as sucrose. In the absence of the "hull factor", ovaries cultured in vitro were found to contain embryos having nuclei in which the DNA content was equivalent to the tetraploid level, while mitosis was almost completely lacking. A similar embryo growth stimulation was obtained when a single leaf was left on an excised barley spike where lemmas and paleas were removed.
FURTHER STUDIES ON INDUCED APOGAMY IN FERNS
Authors: Whittier D. P. , Steeves T. A.
Published: August 2008

Apogamous sporophyte formation has been induced in 14 strains of seven species of normal fern gametophytes using a technique similar to the one reported earlier (Whittier and Steeves, Can. J. Bot. 38, 925–930 (1960)). These gametophytes were supplied with suitable concentrations of sugar in the sterile culture medium for certain lengths of time which resulted in the formation of apogamous sporophytes. This investigation demonstrated that sucrose is more effective in inducing apogamy probably because it produces about half the osmotic potential as an equivalent percentage of glucose. Therefore more sugar can be made available to gametophytes before the osmotic potential deleteriously affects the prothallial growth and apogamy. This confirms the work carried out previously using sugar in the medium and it demonstrates that this method has general applicability for inducing apogamy in ferns. The sugar in the medium is felt to modify the carbohydrate metabolism enabling the prothalli to undergo a thickened growth and develop apogamous sporophytes.
THE PHYSIOLOGY OF HOST-PARASITE RELATIONS: XII. A CYTOPHOTOMETRIC STUDY OF THE DISTRIBUTION OF DNA AND RNA IN RUST-INFECTED LEAVES
Authors: Whitney H. S. , Shaw Michael , Naylor J. M.
Published: August 2008

Uninfected and rusted leaves of Little Club wheat (reaction type 4) were sectioned at intervals up to 15 days after inoculation with Puccinia graminis tritici Erikss. and Henn., race 15B. Infection caused a decrease in the size of the chloroplasts, an increase in size followed by a collapse of the nuclei in the mesophyll cells and an increase in the size of the nucleoli. These effects also occurred, but more rapidly, in infected leaves of Khapli wheat (rust reaction type 1). They were most pronounced in the tissue beneath uredia. Cytophotometry of nuclei in Little Club by the 'two-wavelength' method after staining with the Feulgen reagent showed that there was no increase in the level of DNA in enlarged nuclei at 6 days after inoculation; collapse of the nuclei at 15 days after inoculation was accompanied by the loss of 60% of the DNA originally present. Cytophotometry of nucleoli in nuclei in mesophyll cells stained with azure B after selective removal of DNA with DNase showed that nucleolar enlargement was accompanied by a significant (P = 0.05) increase in RNA. The fungal nuclei stained with the Feulgen reagent, but not after treatment with DNase. The cytoplasm in fungal hyphae, haustorial mother cells and haustoria stained heavily with azure B, but not after treatment with RNase. The absorption spectrum of the stained mycelium was characteristic of the RNA - azure B complex. The results are discussed.
STUDIES ON THE INFECTION PROCESS OF CERATOCYSTIS ULMI (BUISM.) C. MOREAU IN AMERICAN ELM TREES
Authors: Ouellette G. B.
Published: August 2008

Histological studies of controlled beetle and artificially infected American elm trees (Ulmus americana L.) show that the pathogen of the Dutch elm disease, Ceratocyslis ulmi (Buism.) C. Moreau, grows extensively in all tissues of the xylem. The pathogen produces numerous small spores and hyphae, which pass from cell to cell by means of pits and direct penetration of the walls. This explains the rapid spread of the fungus in the host. Disintegration of bordered pits and of cell walls occurs as infection develops. Acute symptoms of the disease are attributed primarily to complete plugging of the vessels of small branches by the fungus and disintegration products. Gradual or partial plugging of vessels of stems and larger branches and disintegration of cell walls per se are postulated as contributing to the chronic symptoms of the disease. Crossing of the fungus from one growth ring to the next in branches is described.Host reactions to the fungus and seasonal changes in nutrients are discussed in relation to resistance. In beetle-inoculated trees, it was found that wounds extending from the crotch down the sides of the branch were the most favorable for the establishment of infection.
THE QUANTITATIVE AND QUALITATIVE RELATIONSHIP OF ULTRAVIOLET AND VISIBLE RADIATION TO THE INDUCTION OF REPRODUCTION IN ASCOCHYTA PISI
Authors: Leach Charles M.
Published: August 2008

Irradiation under either daylight fluorescent lamps or diffuse sunlight stimulated pycnidial development in 40 isolates of Ascochyta pisi. Sporulation varied among these same isolates when grown in darkness, and ranged from none to profuse. Irradiation of selected isolates through filters showed the importance of ultraviolet radiation in stimulating reproduction. The precise relationship of quality, intensity, and length of exposure of radiation to induction of sporulation was studied with monochromatic radiation at 21 °C. Treatment of colonies with monochromatic radiation of wavelengths 2378 Å to 5461 Å (band width 132 Å) at the same intensity of 100 μw/cm2 and with exposures ranging from 1/50 to 20,000 seconds proved conclusively that only ultraviolet radiation induced sporulation. Two wavelengths, 2378 Å and 3131 Å, were notably effective in inducing pycnidial formation over a wide range of exposures. The dosage effective in inducing sporulation decreased with decrease in wavelength. Similarly, the minimum dosage which caused inhibition of sporulation was also least at the shorter wavelengths. Onset and abundance of sporulation differed significantly when the intensity of radiation was varied. The higher the intensity, the shorter was the exposure necessary to stimulate sporulation, or cause inhibition of sporulation. Pycnidia were stimulated by near ultraviolet radiation over a wide range of temperatures (10° to 30 °C), over a wide range of pH values (4.5 to 8.3), and on four commonly used media. Growth (dry weight) under continuous exposure to near ultraviolet radiation did not differ from growth in darkness.The region of mycelium most sensitive to effects of radiation on sporulation at 21 °C was a peripheral zone of young mycelium approximately 1.5 to 2 mm in width. In colonies incubated at a constant temperature of 21 °C, the older mycelium was practically insensitive to radiation. A photoactivated sporulation precursor was able to move small distances from the irradiated peripheral mycelium to newly formed non-irradiated mycelium. Movement of the percursor appeared to be by translocation within hyphae rather than by diffusion through the medium.The location of pycnidia relative to the surface of the medium was dependent on length of exposure and quality and intensity of radiation; absorption of radiation by medium; incubation temperature; and age of mycelium.The size of pycnidia, and the size and shape of conidia both in culture and on the epicotyls of Vicia villosa, were significantly influenced by the dosage and quality of radiation.
STUDIES IN FOREST PATHOLOGY: XXIV. POLYPORUS TOMENTOSUS FR. AS A MAJOR FACTOR IN STAND-OPENING DISEASE OF WHITE SPRUCE
Authors: Whitney R. D.
Published: August 2008

Stand-opening disease in Saskatchewan spruce forests is characterized by the occurrence of patches, often of an acre or more, of declining and dead trees. Polyporus tomentosus Fr. is a major cause of the disease, which develops slowly, with 20 to 30 years elapsing between initiation of attack and death of the trees. Extensive root decay develops before the above-ground symptoms become apparent. Inoculation experiments have shown that P. tomentosus grows about 1.5 in. per year, and that the fungus is parasitic on white spruce.Polyporus tomentosus may enter healthy roots at a point of contact with infected roots; no evidence was found that it entered through root tips or directly from the soil. The fungus remains viable in infected roots for at least 16 years. The disease is commonly associated with injury caused by root-tunnelling weevils in the genus Hylobius. Host vigor did not appear to influence infection or disease development. In culture, the optimum temperature for P. tomentosus was 20 °C and the optimum pH was 4.5. At lower temperatures P. tomentosus appeared to have a competitive advantage over fungi isolated from dying rootlets. Small seedlings grown in agar with P. tomentosus were killed in 8 months. Under these conditions P. tomentosus was much less virulent than Rhizoctonia, solani Kühn and Phytophthora cactorum L. and C. Schroet.
Petrology and textural classification of the Jericho kimberlite, northern Slave Province, Nunavut, Canada
Authors: Kopylova Maya G. , Hayman Patrick
Published: August 2008

The paper presents data on petrology, bulk rock and mineral compositions, and textural classification of the Middle Jurassic Jericho kimberlite (Slave craton, Canada). The kimberlite was emplaced as three steep-sided pipes in granite that was overlain by limestones and minor soft sediments. The pipes are infilled with hypabyssal and pyroclastic kimberlites and connected to a satellite pipe by a dyke. The Jericho kimberlite is classified as a Group Ia, lacking groundmass tetraferriphlogopite and containing monticellite pseudomorphs. The kimberlite formed during several consecutive emplacement events of compositionally different batches of kimberlite magma. Core-logging and thin-section observations identified at least two phases of hypabyssal kimberlites and three phases of pyroclastic kimberlites. Hypabyssal kimberlites intruded as a main dyke (HK1) and as late small-volume aphanitic and vesicular dykes. Massive pyroclastic kimberlite (MPK1) predominantly filled the northern and southern lobes of the pipe and formed from magma different from the HK1 magma. The MPK1 magma crystallized Ti-, Fe-, and Cr-rich phlogopite without rims of barian phlogopite, and clinopyroxene and spinel without atoll structures. MPK1 textures, superficially reminiscent of tuffisitic kimberlite, are caused by pervasive contamination by granite xenoliths. The next explosive events filled the central lobe with two varieties of pyroclastic kimberlite: (1) massive and (2) weakly bedded, normally graded pyroclastic kimberlite. The geology of the Jericho pipe differs from the geology of South African or the Prairie kimberlites, but may resemble Lac de Gras pipes, in which deeper erosion removed upper facies of resedimented kimberlites.
The Spi Lake Formation of the central Hearne domain, western Churchill Province, Canada: an axial intracratonic continental tholeiite trough above the cogenetic Kaminak dyke swarmGeological Survey of Canada Contribution 20070462.
Authors: Sandeman Hamish A. , Ryan James J.
Published: August 2008

The Spi Group is a package of plagioclase porphyritic, amygdaloidal basalt flows and sandstone (Spi Lake Formation) conformably overlain by coarse conglomerate and sandstone (Old Boot Formation). These unconformably overlie the Kaminak Lake segment of the Central Hearne supracrustal belt, western Churchill Province. The Spi Group developed in a small, isolated basin (8 km2) and is older than the Paleoproterozoic Hurwitz Group. Our data demonstrate that the basalts of the Spi Lake Formation are genetically related to the ca. 2450 Ma Kaminak dyke swarm, a speculation previously promoted by some workers based on field characteristics alone. They are continental tholeiites with large ion lithophile and light rare-earth element enriched multielement profiles with prominent high field-strength element troughs. The 143Nd/144Nd compositions overlap the contemporaneous chondritic bulk-earth data. All of these are features we infer to have resulted from mixing of melts from dominantly depleted mid-ocean ridge basalt (MORB) mantle with low-degree partial melts of metasomatically enriched sub-continental lithospheric mantle. These composite magmas then underwent clinopyroxene + plagioclase ± olivine fractionation with minor assimilation of local tonalitic middle crust. The Spi Lake basin is <1 km wide, trends 020° parallel to Kaminak dykes but is discordant to the more common 045° to 070° trends of fold keels of the Hurwitz Group. The basin is a graben filled first with basalt and then molassoid sediments, representing the expression of crustal extension associated with Kaminak dyke emplacement. This indicates that the present erosional surface in the region is broadly at the same level as at the time of both Hurwitz and Spi Group deposition.
Middle–Late Cambrian Rankenella–Girvanella reefs of the Mila Formation, northern Iran
Authors: Kruse Peter D. , Zhuravlev Andrey Yu
Published: August 2008

Following the collapse of the Early Cambrian archaeocyathan–calcimicrobial reef consortium, the Middle–Late Cambrian – Furongian was an interval dominated by purely microbial dendrolite and stromatolite reefs. However, among these latter, a few exceptional occurrences of metazoan reefs are known. One such reef complex occurs in the late Middle – early Late Cambrian – Furongian portion of the Mila Formation of northern Iran. In the otherwise low-energy interval of this formation, the anthaspidellid demosponge Rankenella hamdii sp. nov. is associated with encrusting Girvanella , eocrinoid plates, rhynchonelliformean brachiopod valves and subordinate hyoliths and trilobites in tempestite shell beds; these beds underwent synsedimentary cementation on the seafloor to form hardgrounds. In the succeeding, higher energy interval, a complex of metre-scale bioherms and (or) taphoherms incorporates toppled or transported Rankenella hamdii in association with brachiopods, echinoderm plates, trilobites and some red argillaceous lime mud. Among these, undoubted reefs were constructed from a framework of digitate Rankenella hamdii with thick Girvanella encrustations. These encrustations locally developed as subvertical columnar ministromatolites, which could also merge laterally to form more extensive masses. Subsequent pervasive cementation generated isopachous rinds that preserved the reef framework intact. Coeval and younger Cambrian anthaspidellid–calcimicrobial reefs are known from California–Nevada and Texas, USA. These were heralds of the Early Ordovician resurgence of metazoan reefs.
Évolution morphostructurale du plateau volcano-sédimentaire de Gergovie au Miocène inférieur : implications géodynamiques sur la phase tardi-tectonique du rift de Limagne (Massif central, France)
Authors: Degeai Jean-Philippe , Pastre Jean-François
Published: August 2008

The Gergovie plateau is a Lower Miocene topographically inverted volcano-sedimentary system located in the monogenetic volcanic field of the Limagne rift Tertiary basin. It is composed of three east–west aligned maars partly covered by a basaltic lava flow. The eruption of the central maar (maar 1) occurred at the Oligocene–Miocene transition, during the first volcanic phase. This phreatomagmatic structure was almost totally cut through by the opening of a second maar (maar 2) during the next eruptive phase. The basaltic lava flow at the summit and the eastern maar (maar 3) were placed during a third and last eruptive phase during the Middle or Upper Burdigalian (∼19–16 Ma). Between these periods of volcanism, three fluvial to fluviolacustrine sedimentation episodes, separated by two erosive stages, followed one another. A bedrock thickness of 100–300 m was eroded from maar 2 during the upper Aquitanian and (or) the lower Burdigalian (∼22–19 Ma). This erosion is partly due to a volcano-tectonic uplift in the southern Limagne. The complex morphostructural evolution of the Gergovie plateau demonstrates the north–south geodynamic differentiation of the Limagne rift during the Lower Miocene, since the northern part of the basin corresponded to a relatively calm lacustrine sedimentation area. More generally, the Miocene volcanic field in the South of the Limagne gives an opportunity to study interactions between volcanism, tectonics, and erosion during the late passive rifting activity phase.
Theoretical study with spin-orbit effects and electronic transition moment calculation of the ion NaCs+
Authors: Korek M , Badreddine K , Allouche A R
Published: August 2008

A theoretical study was done of the electronic structure of the molecular ion NaCs+. The calculation is based on nonempirical pseudopotentials and parameterized [Formula: see text]-dependent polarization potential. Gaussian basis sets were used for both atoms and spin-orbit effects were taken into account. Potential energy curves were obtained for 56 lowest electronic states for the symmetries 2∑+, 2Π, 2Δ, and Ω of the molecular ion NaCs+. The spectroscopic constants were calculated for 19 electronic states by fitting the calculated energy values to polynomials in terms of the internuclear distance r. Through the canonical functions approach the eigenvalue Ev, the rotational constant Bv and the abscissas of the turning points were calculated up to 52 vibrational levels for 6 bound states. The dipole moment were calculated in the considered range of the internuclear distance r. The comparison of the calculated values to those available in the literature shows a good agreement. PACS Nos.: 31.10.+z, 31.15.Ar, 31.50.Df, 33.15.Mt