bluuebunny/crossref_metadata_2025 huggingface dataset:
THE EFFECT OF INTERSPECIFIC HYBRIDIZATION ON CERTAIN GENETIC RATIOS IN SWEET CLOVER
Authors: Baenziger H. , Greenshields J. E. R.
Published: August 2008

In crosses involving derivatives of interspecific crosses of (Melilotus alba × Melilotus dentata) and (M. officinalis × M. alba) with pure Melilotus alba, irregular ratios were shown to be common. Previous studies using pure M. alba have indicated simple Mendelian inheritances for many of the characters studied herein. However, when interspecific derivatives are involved, some plants give F2 families that do not fit any Mendelian ratio. Data are presented indicating that in segregations where the deficiency occurs it is always in the genotype that has contributed the gene from the non-recurrent species. Investigations carried out in this study are designed to determine possible causes for these "blurred" ratios.
SOME FACTORS AFFECTING THE GERMINATION OF SPORES OF FOMES IGNIARIUS VAR. POPULINUS (NEUMAN) CAMPBELL, AND THE SIGNIFICANCE OF THESE FACTORS IN INFECTION
Authors: Good H. M. , Spanis W.
Published: August 2008

Spores of F. igniarius collected from different conks at one time, or from one conk at different times of the year, varied significantly in germinability. However, spores collected from one conk within a 3-day period were judged to be sufficiently consistent for use in comparative tests.Spores germinated best on an 8% malt extract medium buffered at pH 4.0. Only a trace of germination occurred on water agar and none occurred on alkaline media. Stimulation by malt extract appeared to be due partly to the sugar content and partly to an unidentified factor.While extracts of the surface wood of aged wounds contained far less of sugars and amino acids than did extracts of fresh sapwood, germination on the former was consistently better. A lower pH appeared to account for most of this advantage but even when the two types of extract were brought to the same pH better germination occurred on the extract of the aged wound.Spores of F. igniarius germinated well at temperatures in the range 20–35 °C. They varied widely in their ability to germinate after storage. Some samples germinated fairly well after 80 days; others failed to germinate after 10 days.These findings are discussed in relation to the problems of infection.
STUDIES ON FUSARIUM WILT OF BANANAS: III. INFLUENCE OF SOIL FUNGITOXINS ON BEHAVIOR OF F. OXYSPORUM f. CUBENSE IN SOIL EXTRACTS AND DIFFUSATES
Authors: Stover R. H.
Published: August 2008

Aqueous extracts from soil obtained (1) by mixing equal volumes of soil and distilled water and filtering until clear, (2) by displacing the soil solution with ethyl alcohol, and (3) by soil perfusion were inhibitory to germination, hyphal growth, sporulation, and chlamydospore formation by Fusarium oxysporum f. cubense. In general, acid loam extracts were less fungitoxic than alkaline clay loam extracts and differences were not related to extract pH. Fungitoxins were reduced by filtering extracts through charcoal, by evaporating or dialyzing the extracts, and by air-drying soil before extracting. Fungitoxins were greatly reduced by filtration through sintered-glass or Seitz filters. Heat sterilization or fumigation with ethylene oxide destroyed most of the fungitoxic effect. However, differences in growth and sporulation between heat-sterilized loam and clay loam extracts and diffusates were often apparent. Fusarium germination, hyphal growth, sporulation, and chlamydospore formation on agar films were inhibited by fungitoxins diffusing through cellulose membranes and by addition of non-sterile soil to 1.5% water agar.High concentrations of nutrients masked and low concentrations reduced effects of fungitoxins in soil extracts and diffusates. The addition of dextrose, glutamic acid, yeast extract, banana sap, or banana roots to extracts stimulated growth and sporulation. Yeast extract or glutamic acid stimulated sporulation at concentrations of 10 p.p.m., particularly where the bacterial population in the extract had been reduced by filtering through sintered glass.Fungitoxins and nutrients interacting, often appeared to act independently on hyphal growth, sporulation, and chlamydospore formation, stimulating or inhibiting one but not the others. Both sporulation and chlamydospore formation, in general, were more sensitive to fungitoxins and nutrients than was hyphal growth. In addition, morphogenic responses of the yellow and non-yellow Fusarium clones to fungitoxins and nutrients were markedly different. Both germination and hyphal growth were greater with the yellow than the non-yellow clone in all extracts. In general, chlamydospores were produced more frequently and in greater numbers in agar films containing diffusates from acid loam than alkaline clay loam. Chlamydospores were formed most rapidly and in greatest abundance on sterile soil-amended or plain agar after 5 to 6 days. In aqueous extracts chlamydospores, if produced, formed after 3 to 5 days. Conidia, if produced, formed within 18 to 42 hours regardless of substrates.The data indicated that fungitoxins in extracts and diffusates were associated with the bacterial soil flora since measures that reduced or altered this flora were reflected in a response by Fusarium.
GLUCOSE CATABOLISM IN PEPPER FRUIT (CAPSICUM FRUTESCENS LONGUM)
Authors: Doyle W. P. , Wang C. H.
Published: August 2008

The glucose catabolism in several varieties of pepper fruit has been investigated by means of tracer techniques employing glucose-1, -2, -3(4), and -6-C14as the labelled substrates. A method is presented whereby the participation of individual pathways in these fruits may be identified and estimated. It was found that 28–36% (among the varieties tested) of the glucose catabolized was routed through a direct oxidative pathway, the remainder being oxidized via the Embden–Meyerhof–Parnas and tricarboxylic acid cyclic processes. No significant difference in pathway distribution was found between green mature peppers and red mature peppers.
OCCURRENCE OF TRAMETES SEPIUM IN INDIA
Authors: Bakshi B. K. , Gibson Shelagh , Singh B.
Published: August 2008

Trametes sepium Berk. is reported for the first time in India from the temperate regions in the Western Himalayas, on structural timber of Cedrus deodara. The sporophores of the fungus as they occur in India and the cultures are described. The identity of the fungus was confirmed by interfertility tests between the Indian and American collections of the fungus.
SEASONAL CHANGES IN METABOLISM OF SPRUCE LEAVES
Authors: Neish C.
Published: August 2008

Sucrose, raffinose, pinitol, shikimic acid, and pungenin were isolated in crystalline form from leafy twigs of both Colorado spruce (Picea pungens Engelm.) and white spruce (Picea glauca (Moench) Voss) collected in winter. Raffinose and sucrose were the main sugars present in winter but raffinose disappeared in early spring and was not found again until autumn. Pungenin was also found in lowered concentrations in summer, and pinitol could not be crystallized from material collected in warm weather.Leafy twigs were harvested at different seasons and allowed to photosynthesize in the presence of C14O2under constant conditions in the laboratory. Winter twigs were found to be convenient and efficient for the preparative biosynthesis of sucrose-C14and raffinose-C14. Hemicellulose was labelled much more rapidly than cellulose. The C14in the hemicellulose was concentrated in the glucose, little being found in the xylose.The relative rates of labelling of the sugars, pinitol, shikimic acid, pungenin, cellulose, and lignin showed some marked seasonal changes.
THE DISTRIBUTION OF SAVANNA SPECIES IN RELATION TO LIGHT INTENSITY
Authors: Bray J. R.
Published: August 2008

The distribution of savanna species in relation to light intensity was investigated during ecologic study of the prairie–forest border in Wisconsin. Four thousand intensity measurements were made in 17 stands, of which 915 were taken over sampled quadrats. Measurements were made on clear days during the midday period in July and August with a Weston photometer, and readings from different stands were considered comparable. Light amplitudes were determined by calculating the percentage of a species in the quadrats of each intensity size class. These classes were based on a log 10 scale after schemes of linear and geometric progression indicated curvilinear distributions would most likely result from a log scale. Forty-seven species distributions were calculated, 43 of which showed normal patterning with distinct modes.The log 10 scale was used to show distribution of light intensity in 16 stands along a gradient from prairie to terminal forest.Light distributions of species on two soil moisture levels showed a highly significant tendency for the lower light amplitude to occur on the drier moisture level. This tendency operated for species at all levels of the soil moisture gradient.Possible mechanisms for the species–light distributions were discussed in relation to growth–light curves and to conditions of soil moisture and evaporation which are correlated with or controlled by light intensity.
AN APPARATUS FOR SURFACE STERILIZATION OF ROOT TIPS
Authors: Slankis V.
Published: August 2008

An apparatus for surface sterilization of root tips is described. This apparatus makes sterilization more accurate and considerably more efficient compared with methods previously employed. It can be successfully used under field conditions.
PYTHIUM ROT OF SAINTPAULIA, THE AFRICAN VIOLET
Authors: Thompson H. S.
Published: August 2008

Many fungi and bacteria were isolated from African violets affected with root and crown rot, but, of these, Pythium ultimum Trow was the only organism that proved to be pathogenic to this host. P. ultimum readily infected leaf cuttings, rooted cuttings, and the petioles and leaves of plants when these were in contact with moist infested soil. Inoculum placed against the crown of a healthy plant also caused infection, but the lesion developed slowly and usually only a small amount of tissue was decayed. On the other hand, when the crowns and roots of healthy plants were set in infested soil they remained healthy; but they became predisposed to attack when they were subjected to prolonged exposure to light of very high intensity or when the roots were infested with nematodes (Meloidogyne sp.). Alternating periods of overwatering and drying did not increase the susceptibility of these healthy plants. When young plants, large enough to be planted singly in soil, were allowed to remain in vermiculite, a nonnutritive substrate, until they yellowed and were then planted in infested soil, they became infected and completely decayed. However, plants at least a year old that had been placed in vermiculite until they yellowed and were then planted in infested soil did not become infected.Infection and decay of leaf or rooted cuttings caused by P. ultimum occurred readily throughout the range of 10°–30 °C. The disease also occurred over a wide range of soil moisture, but was favored by the higher levels.When leaf cuttings and rooted cuttings of 30 varieties of African violets were planted in infested soil, all varieties proved susceptible.
NUCLEAR PHENOMENA IN THE LIFE CYCLE OF GANODERMA LUCIDUM (LEYSS. EX FR.) KARST.
Authors: Sarkar Anjali
Published: August 2008

Nuclear behavior in the life cycle of Ganoderma lucidum (Leyss. ex Fr.) Karst., a common polypore in West Bengal, India, has been studied. Each young basidium is binucleate and the nuclei soon fuse to form a syncaryon which undergoes three successive divisions, of which the first is reductional, to produce eight daughter nuclei. Four nuclei pass into the four spores, one into each, and the other four, remaining within the basidium, finally degenerate. Thus at first each basidiospore contains one nucleus which may or may not divide further. On germination, the spores give rise to primary mycelia with uninucleate or multinucleate cells. Secondary mycelia, formed by the union of two compatible primary mycelia, have nodose-septate hyphae in which most of the cells are dikaryotic although cells with more than two nuclei are not uncommon.The chromosome number, counted from metaphasic plates, has been found to be 10 = 2n.
CHROMOSOME BREAKAGE INDUCED IN VICIA FABA ROOT TIPS BY 2,4,6-TRI(ETHYLENEIMINO)-1,3,5-TRIAZINE
Authors: Wakonig Resa , Arnason T. J.
Published: August 2008

After a 12-hour treatment in 10−5 M solution of 2,4,6-tri(ethyleneimino)-1,3,5-triazine (TEM), up to 29% of Vicia and 31% of Allium root cells in anaphase had bridges or fragments. The most abundant metaphase aberrations were chromosome breaks and chromatid interchanges. Aberrations were more numerous after 6-hour treatment with 2 × 10−5 M than after 12-hour treatment with 10−5 M solution. The peak aberration frequencies were reached at 36 hours after 2 × 10−5 M treatments and slightly earlier with weaker solutions. Many chromosomes had incomplete breaks. Sister reunions of chromatids occurred with equal frequency in centric and acentric fragments. Sister reunion was 1.5 times as frequent as chromatid exchange. Along the length of the satellite chromosome, breaks occurred at random except for a slight favoring of the heterochromatic region. Per unit of length the short chromosomes were about 3 times as susceptible to breakage and exchange as satellite chromosomes. TEM introduced through cut stems had no discernible effects on Tradescantia microspore chromosomes even after 3 to 5 days of treatment.
TRANSLOCATION OF C14-LABELLED AMINO ACIDS AND AMIDES IN THE STEMS OF YOUNG SOYBEAN PLANTS
Authors: Nelson C. D. , Gorham Paul R.
Published: August 2008

Translocation of each of seven amino acids and three amides was measured for periods of 5 minutes or less after introduction through the cut petiole of a primary leaf. The compounds used were asparagine, urea, glutamic acid, glutamine, glycine, norleucine, arginine, serine, alanine, and aspartic acid. During the short times of these experiments it was found that each compound was translocated downward as such. The amount of carbon-14 in the stem decreased logarithmically from the point of introduction. Each compound was translocated with unchanged velocity past a short section of stem killed with steam. There was no translocation of aspartic acid through a stem that had an entire internode killed with steam. Potassium cyanide (10−2 M) did not inhibit the velocity of translocation of any of the compounds although the logarithmic pattern of distribution of arginine was altered. The minimum velocity of translocation was different for each compound and varied between 350 cm per hour for asparagine and 1400 cm per hour for aspartic acid.
COMPARATIVE EFFECTS OF 3-INDOLYLBUTYRIC ACID, 2,3,5-TRI-IODOBENZOIC ACID, AND β-NAPHTHOXYACETIC ACID ON FLOWER GROWTH AND FLOWER WEIGHT OF THE CAULIFLOWER (BRASSICA OLERACEA)
Authors: Das B. C.
Published: August 2008

Three synthetic growth-promoting substances were administered to cauliflower plants (Brassica oleracea) to determine their effect on flower weight and flower growth. A Youden square experimental design was employed to set up treatment groups for all possible combinations of three substances at four concentration levels and three frequencies of application, and an untreated control group. The substances employed were 3-indolylbutyric acid (IBA), 2,3,5-tri-iodobenzoic acid (TIBA), and β-naphthoxyacetic acid (NOXA); concentrations used were 0.01, 0.2, 4.0, and 80.0 parts per million; and frequencies adopted were 2, 3, and 6 times in a 12-day period. Final flower weights were analyzed by an analysis of variance which showed that the treatments differed significantly (P <.01). Treatments with NOXA and IBA produced flowers weighing significantly more than those of the control group. Flower growth was characterized by a rapid initial rise, which subsequently levelled off in the control group. For treated groups, the initial rise continued throughout the flowering period. The results suggest that the use of certain synthetic growth-promoting substances may be feasible commercially for enhanced production of cauliflower crops.
INTERNAL WATER RELATIONS OF YELLOW BIRCH AT CHALK RIVER
Authors: Fraser D. A. , Dirks H. T.
Published: August 2008

Wood moisture was measured in the butt of healthy and decadent yellow birch trees growing on various sites in the summers of 1950 and 1952. The moisture content decreased from almost 100% in May to about 60% in late June when the leaves were fully unfolded. Wood moisture was usually 5 to 15% higher in the butt of decadent trees than in healthy trees during the 2 years of investigations. It was higher in the trunk of trees on a dry site during a wet summer and on a wet site during a somewhat dry summer.Relative turgidity in leaves was measured in mature trees as well as in leaves of seedlings growing on soils with varied moisture contents. Relative turgidity was usually less during the day. During periods of drought it decreased even during the night. Exceptions observed may have been caused by leaf absorption of dew. In young birch seedlings relative turgidity values varied between 65 and 50% in soils ranging from 100 to 70% of field capacity. As the soil wilting point was approached, relative turgidity of leaves decreased to about 35%.
NUTRITIONAL STUDIES ON THE GENUS HIRSUTELLA: II. NITROGEN UTILIZATION IN A SYNTHETIC MEDIUM
Authors: MacLeod D. M.
Published: August 2008

The growth responses of Hirsutella gigantea to different nitrogen sources were studied. Experiments showed that the mycelium hydrolyzate contained at least 14 of the amino acids, that the fungus was unable to utilize inorganic nitrogenous compounds, that ammonium tartrate was inferior to amino-nitrogen, and that the L or DL isomers of the different amino acids induced better growth than did the D form.The 10 most suitable nitrogen sources in order of decreasing growth were: L-glutamic acid, L-tyrosine, ammonium tartrate, DL-aspartic acid, L-proline, L-arginine, L-leucine, DL-α-alanine, DL-serine, and DL-histidine. The total yield, however, obtained in a synthetic medium with each of these substances was shown to be directly dependent upon the quantity of inoculum used. The enhanced growth resulting from the addition of increased inoculum is ascribed to accessory growth factors carried over with the mycelial fragments despite six washings in saline.The maximum growth of H. gigantea developed in a dextrose–salts medium containing L-glutamic acid as a source of nitrogen, and yeast extract, inoculum filtrate, and liver fraction "L" as a source of growth factors.The lack of uniformity associated with nutritional studies conducted in chemically defined media has been briefly mentioned.
DEPOSITION OF CELL WALLS IN OAT COLEOPTILES
Authors: Setterfield G. , Bayley S. T.
Published: August 2008

Autoradiographs of squashed cell walls from coleoptile segments grown on a tritiated sucrose solution show that wall deposition is not localized at a few synthetic centers but occurs over the whole area of the wall. Autoradiographs of sections of such segments also demonstrate that wall materials are deposited throughout the depth of the thickened outer epidermal walls. Electron microscopy of sections of coleoptile cells failed to detect any evidence for deep penetration of cell walls by the cytoplasm. It is concluded that in these and some other types of cell walls, individual enzyme molecules bound in an organized pattern to the wall are responsible for synthesizing new wall materials from precursors diffusing into the wall.
THE CONTROL OF GROWTH AND DEVELOPMENT IN RED CLOVER (TRIFOLIUM PRATENSE L.): II. LIGHT, TEMPERATURE, AND THE INFLUENCE OF GROWTH REGULATORS
Authors: Cumming Bruce G.
Published: August 2008

Morphogenesis of Dollard red clover clones has provided indirect evidence that endogenous auxin level and, or, sensitivity of response of tissues to auxin vary according to light and temperature and as a function of genotype.The amount of growth and development was less in autotetraploid than in diploid plants.Root formation on propagules was influenced by relatively short-term different daylength pretreatments of intact plants; also, by the daylength and light intensity imposed during rooting.Under reduced light intensity extension growth already initiated was increased and this was related to increased "sensitivity" of growth response of stems and petioles to applied auxin.Morphogenetic effects relatively similar to those caused, respectively, by shortening the daylength and by lengthening the daylength resulted from antiauxin (TIBA) as compared with auxin (IAA) treatments.Concentrations of IAA that were primarily stimulatory to growth under shorter daylengths were inhibitory under continuous light. The primary stimulatory effect of IAA was on bud formation under SD but on stem elongation under LD.The relatively similar and additive effects of photoperiod, applied auxin, and cold pretreatment are discussed. It is postulated that in red clover a greater endogenous diffusible auxin level is required for optimum formation of stems and inflorescences than for buds and roots.Manipulation of light and temperature and the use of growth regulators provide added precision in the control of growth and development in red clover.
CHROMOSOME NUMBERS AND TAXONOMIC NOTES ON NORTHERN GRASSES: I. TRIBE TRITICEAE
Authors: Bowden Wray M.
Published: August 2008

Chromosome numbers and voucher specimens are recorded for some collections of the tribe TRITICEAE Dumort., mainly collected in Canada. The somatic chromosome numbers of the following are recorded: (1) Elymus canadensis L., 2n = 28; (2) Elymus cinereus Scribn. & Merr., 2n = 28 and 2n = 56; (3) Elymus glaucus Buckl., 2n = 28; (4a) Elymus innovatus Beal subsp. innovatus, 2n = 28; (4b) Elymus innovatus Beal subsp. velutinus Bowden, 2n = 56; (5) Elymus wiegandii Fern., 2n = 28; (6) Eremopyrum triticeum (Gaertn.) Nevski, 2n = 14; (7) Sitanion hystrix (Nutt.) J. G. Smith, 2n = 28; (8) × Agrohordeum macounii (Vasey) Lepage, 2n = 28; (9) × Agroelymushirtiflorus (Hitchc.) Bowden, 2n = 28; and (10) × Agroelymus ungavensis (Louis-Marie) Lepage, 2n = 28. Because var. coreensis Hack. is an earlier varietal name, Elymus mollis Trin. var. coreensis (Hack.) Bowden replaces E. mollis Trin. var. japonicus Bowden as the name for the variety that occurs on the shores of the Sea of Japan.
EXPRESSION OF LEAF RUST RESISTANCE IN SELKIRK AND EXCHANGE WHEATS AT DIFFERENT STAGES OF PLANT DEVELOPMENT
Authors: Samborski D. J. , Ostapyk W.
Published: August 2008

Unexpectedly heavy leaf rust development was observed on mature (ripe) field-grown plants of the resistant wheat varieties, Selkirk and Exchange. Greenhouse experiments with pure races of leaf rust showed that a partial breakdown of both seedling and adult plant resistance occurred when the plants were approaching maturity. This change in resistance would not affect yields but could result in exaggerated estimates of rust damage. Leaf rust readings in rust nurseries, at least on these varieties, should be made before the plants are ripe.
STUDIES OF NECTAR SECRETION IN EXCISED FLOWERS: II. THE INFLUENCE OF CERTAIN GROWTH REGULATORS AND ENZYME INHIBITORS
Authors: Shuel R. W.
Published: August 2008

Concentrations of 5 × 10−5 M to 5 × 10−4 M of 3-indoleacetic (IAA), α-naphthaleneacetic, or 2,4-dichlorophenoxyacetic acid usually reduced nectar secretion in excised flowers of Antirrhinum majus L. cultured on sugar solutions. The major part of the reduction occurred at relatively low concentrations of the growth regulators. The percentage reduction by IAA remained fairly constant when the sugar concentration of the medium was varied. Although the growth-regulating compounds promoted ovary growth, increased growth did not appear to have been the cause of reduced nectar yields. IAA sometimes increased nectar secretion. The effect of IAA on secretion was modified by 2,3,5-triiodobenzoic acid. Nectar secretion was partially inhibited by iodoacetic acid, sodium arsenate, dinitrophenol, sodium azide, and fluoroacetic acid at concentrations which caused no visible injury to flowers. Two inhibitors of phosphate transfer, dinitrophenol and sodium arsenate, modified the influence of IAA. The data support the hypothesis that nectar secretion is an active process.
SOME SHORT-TERM EFFECTS OF INCREASED CARBON DIOXIDE CONCENTRATION ON PHOTOSYNTHETIC ASSIMILATION IN LEAVES
Authors: Mortimer D. C.
Published: August 2008

The photosynthetic assimilation of radioactive carbon dioxide by leaves from seven plant species was continuously measured in a closed system in which the concentration of carbon dioxide was abruptly increased from the atmospheric level to predetermined levels up to 2.0%. The rate of assimilation immediately increased, approximately proportional to concentration, but after about one minute began to decrease. The degree and duration of the decrease in rate of uptake varied with plant species and with concentration. This increased uptake of carbon dioxide influenced the distribution of carbon among the products of assimilation. At the lowest concentration (0.1%), serine, glycine, and glyceric acid contained most of the carbon assimilated during the experimental period, but at higher concentrations these were replaced by sucrose and alanine.
INHERITANCE OF THE TYPE OF SOLID STEM IN GOLDEN BALL (TRITICUM DURUM): II. CYTOGENETICS OF THE RELATION BETWEEN SOLID STEM AND OTHER MORPHOLOGICAL CHARACTERS IN HEXAPLOID F5 LINES OF A HYBRID WITH RESCUE (T. AESTIVUM)
Authors: Larson Ruby I.
Published: August 2008

Cytogenetic analysis of selected F5 lines of the pentaploid hybrid, Rescue (Triticum aestivum L. emend. Thell.) × Golden Ball (T. durum Desf.) showed that chromosome XVI is the member of the D genome of Rescue that prevents transfer of the more solid top culm internode of Golden Ball to hexaploid segregates. It also produces a lax spike. Chromosome XX, which is the D-genome chromosome mainly responsible for the hollowness of hollow-stemmed hexaploids, probably has little effect in Rescue. Long awns were associated with low chromosome number but not with stem solidness or dense spike; therefore, the chromosome that suppresses awn development is probably not XVI.Three 42-chromosome segregates from the cross were more solid in the top internode than Rescue, presumably because of segregation of genes in the A and B genomes. It is unlikely, however, that a fully hexaploid segregate with a top internode as solid as that of Golden Ball can be selected from this hybrid.
THE EFFECTS OF DISODIUM VERSENATE ON THE ROOTS OF TOMATO SEEDLINGS
Authors: Cormack R. G. H.
Published: August 2008

This paper describes the effects produced by the metal-chelating reagent disodium versenate on the epidermal cells of living tomato roots. Striking abnormalities characterized by the disconnection or separation of every epidermal cell and by the suppression of root-hair production were consistently observed. The present study confirms the earlier observation that the epidermal cells of tomato roots are all of the "long-cell type". Individual differences in behavior of epidermal cells are based on differences in ability to incorporate calcium into their elongating walls.
STUDIES IN WOOD-INHABITING HYMENOMYCETES: IV. THE GENUS CORIOLELLUS MURR.
Authors: Sarkar Anjali
Published: August 2008

The six species, Coriolellus sepium (Berk.) Murr., the type of Coriolellus Murr., C. serialis (Fr.) Murr., C. malicola (Berk. & Curt.) Murr., C. heteromorphus (Fr.) Bond. & Sing., C. variiformis (Peck) n. comb., and C. sinuosus (Fr.) n. comb., are similar in cultural characters and in the morphological characters of their sporophores and so constitute a homogeneous group. Detailed morphological and cultural descriptions of each of the species, together with the results of interfertility tests, are presented, along with a revised description of the genus, a description of its cultural characters, and diagnostic keys.
DIFFERENTIAL EFFECTS OF MALEIC HYDRAZIDE ON THE GROWTH OF LEAF AND STEM RUSTS OF WHEAT
Authors: Samborski D. J. , Person Clayton , Forsyth F. R.
Published: August 2008

The effect of maleic hydrazide on leaf rust and stem rust of wheat was investigated, using intact plants supplied with maleic hydrazide through the roots, detached leaves floated on solutions of maleic hydrazide, and spores germinated on maleic hydrazide solutions in agar. In each case the growth of leaf rust was inhibited at concentrations of maleic hydrazide which had no effect on the growth of stem rust. Some resistant wheat varieties became susceptible to rust after treatments with levels of maleic hydrazide which were not inhibitory to rust development. In some experiments, leaf rust races reacted differentially to maleic hydrazide. Both nutritional and inhibitory factors could be involved in resistance and host–pathogen specificity.
STUDIES ON FUSARIUM WILT OF BANANAS: V. PATHOGENICITY AND DISTRIBUTION OF F. OXYSPORUM f. CUBENSE RACES 1 AND 2
Authors: Stover R. H. , Waite B. H.
Published: August 2008

Two naturally occurring races of the Fusarium wilt or Panama disease fungus, F. oxysporum f. cubense (E.F.S.) Snyd. and Hans., have been identified. Race 1 is world-wide in distribution and attacks certain AAA triploids of Musa acuminata, of which variety 'Gros Michel? is the most important, and Musa textilis. Race 2 has been identified in Honduras, El Salvador, Puerto Rico, Virgin Islands, and the Dominican Republic and attacks certain ABB triploids of M. acuminata × M. balbisiana known as 'Chato', 'Bluggoe', 'Rulo', or 'Chamaluco'. Both races are pathogenic on 3- to 4-month-old seedlings of M. balbisiana, M. schizocarpa, and M. acuminata ssp. banksii, but the race 2 clone was less pathogenic than the race 1 clones tested. Mature M. balbisiana is immune to rhizome infection in the field. 'Odoratum' and 'Inodoratum' cultivars of F. oxysporum f. cubense are found within race 1; only the 'Inodoratum' cultivar is found within race 2. Circumstantial evidence indicates an independent development of race 2 in different areas. Race 2 wilt-susceptible ABB triploids hybridize and set seed with pollen from diploid M. balbisiana (BB) and M. acuminata (AA), the two ancestors of the cultivated banana. This will facilitate a study of the inheritance of wilt resistance to F. oxysporum f. cubense races 1 and 2.
THE VEGETATION OF NORTHERN MANITOBA: IV. THE CARIBOU LAKE REGION
Authors: Ritchie J. C.
Published: August 2008

Based on the findings of one season of field work, an account is given of the vegetation and flora (vascular plants) of the immediate vicinity of Caribou Lake in northeast Manitoba. The plant communities are grouped according to physiographic position. Their chorology is presented in the form of a map which was compiled from interpretation of vertical aerial photographs of the area. The appearance of the various vegetation types on the aerial photographs is described.The prevalent vegetation of mesic sites is a tundra community dominated by ericoid shrubs. There is strong evidence that much of this treeless vegetation occupies sites where trees once grew; they have been removed by fires. Recent alluvium bears stands of Picea glauca (white spruce) which shows good growth. Shallow wet peats are covered by black spruce stands with shrubs and mosses, chiefly Sphagnum. Deeper peats, usually with shallow active layers, bear heath or sedge–cottongrass tundra.
EFFECT OF 3-(4-CHLOROPHENYL)-1,1-DIMETHYLUREA ON DRY MATTER PRODUCTION, TRANSPIRATION, AND ROOT EXTENSION
Authors: Minshall Wm. Harold
Published: August 2008

Extension growth of the chlorophyll-containing roots of Hydrocharis morsusranae was inhibited by 0.5 p.p.m. of 3-(4-chlorophenyl)-1,1-dimethylurea (monuron) whereas concentrations close to the water saturation point of 230 p.p.m. were required to inhibit extension growth of the non-chlorophyll-containing attached roots of Zea mays and Phleum pratense and the detached roots of Pisum sativum.A total of 15–20 μg of monuron per gram fresh leaf applied through the cut petiole of detached primary leaves of Phaseolus vulgaris inhibited the increase of dry matter by 90% and suppressed transpiration 40–50%. Internal concentrations of 1–2 μg/g of monuron produced simultaneous enhancement of dry matter increase and of transpiration but concentrations of 5–10 μg/g produced a suppression of dry matter increase concurrently with an enhancement of transpiration. Age of leaf and the time of year in which the plants were grown altered the critical internal concentration levels required to affect dry matter increase and transpiration.Analysis of detached leaves treated with 15–20 μg/g monuron indicated a marked suppression of the formation of non-water-soluble carbohydrate, a slight suppression of the formation of water-soluble nitrogen, but little or no effect on water-soluble carbohydrate or on non-water-soluble nitrogen.In detached leaves o-phenanthroline, 3-phenyl-1,1-dimethylurea, and 3-(3,4-dichlorophenyl)-1,1-dimethylurea resembled monuron closely in symptom development and in their effect on dry matter production and transpiration. Iodoacetamide, 2,4-dinitrophenol, and 8-hydroxyquinoline each produced some effects similar to monuron but differed from it in certain respects; Thiourea, sodium diethyldithiocarbamate, sodium fluoracetate, ethyl-NN-diphenylcarbamate, and hydroxylamine hydrochloride were without noticeable effect.
OCCURRENCE OF LIGNICOLOUS FUNGI IN NORTHERN ATLANTIC AND PACIFIC MARINE LOCALITIES
Authors: Meyers S. P. , Reynolds E. S.
Published: August 2008

The submergence and systematic examination of basswood and yellow pine panels at the far northern marine sites at Kodiak, Alaska; Nanaimo, British Columbia; St. Andrews, New Brunswick; Halifax, Nova Scotia; Liverpool, Nova Scotia; and Argentia, Newfoundland, during periods of water temperature of 0 °C to 15 °C, has demonstrated the abundance of an active ascomycetous and deuteromycetous mycota. The dominant fungal biota includes Lulworthia, Ceriosporopsis, Peritrichospora, and Halosphaeriopsis, and the Imperfect genera Piricauda, Humicola, and representatives of Helicosporae. Incubation of these infested wood panels has indicated fungal attack upon the panels in addition to that found at the initial examination, and has facilitated a more complete evaluation of the total lignicolous mycota, as well as establishing the early infestation of the wood. Differences in the dominant mycota between northern and southern environments are apparent, especially among the Deuteromycetes. Various genera and species extremely prevalent in warmer oceanic areas have not been found in colder marine environments.
FORMATION OF MICROENDOSPORES IN CERATOCYSTIS ULMI (BUISM.) C. MOREAU
Authors: Ouellette G. B. , Gagnon C.
Published: August 2008

A morphological study of several isolates of Ceratocystis ulmi has revealed that spores and hyphae of this fungus contain minute cytoplasmic particles that behave like spores (microendospores). The different stages of development of these microendospores are described and some implications of the findings are briefly discussed.
SOME WEED HOSTS OF PRATYLENCHUS PENETRANS IN PREMIER STRAWBERRY PLANTATIONS
Authors: Townshend J. L. , Davidson T. R.
Published: August 2008

Fifty-five species of weeds and seven of cultivated plants were collected from root rot areas in strawberry plantations and found to be infected with Pratylenchus penetrans (Cobb 1917) Filip. & Stek. 1941. Perennial plant species with soft-textured roots contained larger populations of P. penetrans and had more extensive root necrosis than those plant species with hard-textured roots.
COLD HARDENING AND COLD HARDINESS OF YOUNG WINTER RYE SEEDLINGS AS AFFECTED BY STAGE OF DEVELOPMENT AND TEMPERATURE
Authors: Andrews J. E.
Published: August 2008

Young winter rye seedlings, grown and hardened at 1° or 1.5 °C in the dark, developed a high level of cold hardiness at two stages prior to emergence of the first leaf. The first maximum occurred when coleoptiles were less than about 1 mm in length and was followed by a decrease in hardiness. A second and higher maximum occurred when coleoptiles were about 15–30 mm in length (5 weeks at 1.5 °C; 7 weeks at 1 °C) and it was followed by a rapid decrease in hardiness beginning at about the time the leaf broke through the coleoptile. Genetic differences corresponding with those obtained in the field were established by hardening seedlings for 7 weeks at 1 °C and exposure to −15 °C for 16 hours or by hardening for 5 weeks at 1.5 °C and exposure to −14 °C for 16 hours. The use of a lower (−4 °C) hardening temperature resulted in a large increase in cold hardiness at the younger stages of development but little or no increase where seedlings had already reached a maximum of hardiness from exposure to 1.5 °C for 5 weeks. Satisfactory genetic differences were not determined by exposure to −14 °C for 16 hours after hardening at −4 °C. In general the response to hardening of young winter rye seedlings was similar to that found with winter wheat.
OVULE DEVELOPMENT IN DIPLOID RED CLOVER
Authors: Povilaitis Brontus , Boyes J. W.
Published: August 2008

In red clover only one ovule of the two in each ovary regularly develops into a seed. Results of two experiments designed to reveal the fate of the ovules initially present provide a basis for comparing some features of ovule development in high- and low-seed-yielding plants. High-yielding plants produced embryo sacs in over 70% of ovules whereas low-yielding ones produced them in about 40%. The ability to produce embryo sacs seems to be genetically determined but strongly influenced by environment and occasionally by meiotic irregularities. Development started in about 85% of the fertile ovules in the high-yielding plants but in only about 60% of them in low-yielding plants. Apparently there was slow or limited growth of pollen tubes in the latter plants. Nearly 55% of the ovules developing just after fertilization matured into seeds in the high-yielding plants but only about 25% in the low ones. The higher frequency of ovule collapse in low-yielding plants seems to be a consequence of the delayed fertilization followed by retarded growth of the embryos and endosperms.Although a few more ovules did start to develop in out-crosses than in sib-crosses, the more vigorous growth of the endosperm seems quite important in accounting for the superior seed yields in the out-crosses. Also a few more ovules started to develop when the pollen came from a high-yielding plant instead of a low-yielding one and this initial advantage seems to lead to improved seed production.It is suggested that low-seed-producing plants may have certain genes that act like weak self-incompatibility alleles by inhibiting pollen tube growth, or, that their genetic constitutions are such that they cannot produce enough embryo sacs and/or support the growth of pollen tubes and ovules.
POPULATION AND VIABILITY STUDIES OF HELMINTHOSPORIUM SATIVUM IN FIELD SOILS
Authors: Chinn S. H. F. , Ledingham R. J. , Sallans B. J.
Published: August 2008

The population and viability of spores of Helminthosporium sativum from two locations in each of 100 cultivated fields in Saskatchewan were determined in the spring of 1959. The determinations were made by the flotation–viability count method as described herein. Spore numbers in the different samples ranged from a count of less than 8 to 893 with an average of 118 per gram of soil. A predominant number of the samples contained 200 or less spores per gram. Soils summerfallowed or cropped to cereals in 1958 did not differ significantly in spore populations. The coefficient of correlation between the populations of the paired samples in the fields was 0.83. Viability of spores varied from 11 to 100%; a relatively small number of the samples was in the 11 to 30%, and the others were fairly evenly distributed in the 31 to 100% range. Evidence is presented to support the reliability of the flotation–viability count method. The applicability of the method to studies of various root rot problems and the behavior of certain fungi, other than H. sativum, in soil is discussed.
MICROFUNGI: V. CONOPLEA PERS. AND EXOSPORIUM LINK
Authors: Hughes S. J.
Published: August 2008

The history of the generic names Conoplea Pers. and Exosporium Link is traced and many of the early species names are explained from type or authenticated collections. Conoplea, typified by C. sphaerica, replaces Streptothrix Corda. Streblocaulium Chev. is probably a synonym of Conoplea. Six species and one variety of Conoplea are illustrated and described.
STUDIES IN ASCOCHYTA PISI LIB.
Authors: Brewer D.
Published: August 2008

The existence in peas of both physical and physiological resistance to attack by Ascochyta pisi was indicated. Infection was possible at constant temperatures ranging from 45 to 80° F. The temperature subsequent to incubation had a marked effect on infection: the appearance of the symptoms was delayed and the number and size of lesions were increased at the lower temperatures. A. pisi can utilize nitrate, ammonium, amide, and amino nitrogen. Growth is dependent upon both pH and the nitrogen source. A wide variety of carbon sources can be utilized by A. pisi but the isolates differ with regard to their abilities to utilize the different carbon sources. The pH of the medium is of importance at the initiation of pycnidial production. Exhaustion of the carbon supply is apparently a factor in the initiation of sporulation.
PHOTOPERIODIC RESPONSE IN SEEDLINGS OF FIVE SPECIES OF BETULA AND PINUS
Authors: Vaartaja O.
Published: August 2008

The existence of photoperiodic response was experimentally established in Betula lenta, B. mandshurica var. japonica, B. glandulosa, Pinus lambertiana, and P. monticola. The responses of seedlings from different latitudes and altitudes were in accordance with the theory of photoperiodic ecotypes.
DORMANCY STUDIES IN SEED OF AVENA FATUA: 2. A GIBBERELLIN-SENSITIVE INHIBITORY MECHANISM IN THE EMBRYO
Authors: Naylor J. M. , Simpson G. M.
Published: August 2008

Natural inhibition of germination in A. fatua L. involves restriction of both sugar accumulation and utilization of sugar in growth. Both these metabolic blocks are independently overcome by exogenous gibberellic acid (GA). Evidence has been found for the presence of a natural gibberellin in seeds of A. fatua L. The control of dormancy is probably by a gibberellin-inhibitor antagonism since at least one inhibitor has been shown to intervene specifically in sugar production and this latter effect can be reversed by GA. The evidence presented here supports the view that control of germination during the period of after-ripening is through changes in inhibitor content rather than in endogenous gibberellin.
NORTHERN PYRENOMYCETES: II. GASPESIAN PARK
Authors: Barr Margaret E.
Published: August 2008

Two collecting trips in Gaspesian Park, Quebec, during the summer of 1957, yielded a considerable number of pyrenomycetes. In this paper records of 87 species or varieties in 46 genera are presented. Two new species, Linocarpon umbelliferarum Barr and Pseudomassaria foliicola Barr, are described. Five previously described species are transferred to other genera, and the following new combinations are proposed: Gibbera cassandrae (Peck) Barr, Gibbera grumiformis (Karsten) Barr, Gibbera kalmiae (Peck) Barr, Gibberidea kalmiae (Peck) Barr, and Limacinia arctica (Woronichin) Barr.
GROWTH AND MORPHOGENESIS IN THE CANADIAN FOREST SPECIES: IV. RADIAL GROWTH IN BRANCHES AND MAIN AXIS OF PINUS RESINOSA AIT. UNDER CONDITIONS OF OPEN GROWTH, SUPPRESSION, AND RELEASE
Authors: Forward Dorothy F. , Nolan Norah J.
Published: August 2008

The analysis of growth of a pine tree has been extended to include the primary branches, and this paper reports observations on radial growth, as expressed by ring width.Trees from contrasting situations are compared, and the deliberate release of one tree from suppression permits the attribution of specific changes in growth to the change in external condition of the tree.The primary branches provide a series of axes that automatically undergo a change in nutritional status, although the distal portions of all of them are produced simultaneously. Every primary branch is initiated at the apex of the tree and each year is overlaid by one more whorl of branches; so it advances to a relatively lower position in the tree each year, and itself adds one more internode.The upper branches and those portions of lower ones that were formed while near the top of the tree repeat the pattern and configuration of growth in the main axis. Advance of a branch to an inferior position is associated with severe suppression and a redistribution of growth gradients.
FUNGICIDAL ACTION AS AFFECTED BY INTERACTION OF NICKEL CHLORIDE, NABAM, ZINEB, AND ZINC SULPHATE
Authors: Forsyth F. R. , Unwin C. H.
Published: August 2008

Protectant fungicidal action of mixtures of nabam, zineb, nickel chloride, and zinc sulphate was evaluated by means of a "microbeaker method" and the slide germination method, using as test organisms the fungi causing leaf rust of wheat, crown rust of oats, early blight of tomatoes, and brown rot of peaches. All of the fungicides tested were more effective against the two rusts than against the organisms causing early blight and brown rot. The relatively insoluble nickel ethylenebisdithiocarbamate was much less effective than the other chemicals tested. Ratios (w/w) of nickel chloride hexahydrate to zineb around unity and to nabam plus zinc sulphate from 2–10 to 1 showed an unfavorable effect on fungitoxic activity against urediospores of P. recondita. The ratio showing greatest antagonism varied, depending on the test organism used and whether or not tankmix or wettable powder zineb was used. The formation of nickel ethylenebisdithiocarbamate in the aqueous solution and its low fungicidal activity adequately explain the results obtained.
STUDIES OF MEIOSIS IN THE GENUS SAXIFRAGA OF THE PACIFIC NORTHWEST
Authors: Beamish Katherine I.
Published: August 2008

A cytogenetic study of the genus Saxifraga in the Pacific Northwest has been initiated as a contribution toward a better understanding of relationships within the genus. The present paper reports work done on nine species or groups of morphologically similar species and varieties (each group termed a "plexus") which have so far been studied. The nine species or groups of species are S. tolmiei, S. bronchialis, S. integrifolia, S. ferruginea, the S. montanensis plexus, the S. occidentalis plexus, S. odontoloma, S. lyallii and S. mertensiana. Meiosis in pollen mother cells of one species was found to be generally regular, pollen fertility high. In every other species or plexus a variable and sometimes very high degree of meiotic irregularity was present. Pollen fertility was often much reduced. The cause of meiotic disturbances has not yet been discovered. Consideration is given to the ways in which the species may succeed in spite of reduced pollen fertility. Such irregular meiotic divisions would be difficult to use in cytogenetic studies as a standard for comparison with meiosis in artificial hybrids.