bluuebunny/crossref_metadata_2025 huggingface dataset:
CHROMOSOME NUMBERS AND TAXONOMIC NOTES ON NORTHERN GRASSES: II. TRIBE FESTUCEAE
Authors: Bowden Wray M.
Published: August 2008

Chromosome numbers and voucher specimens are recorded for some collections of the tribe FESTUCEAE Dumort., mainly collected in Canada. The somatic chromosome numbers of the following are recorded: (1a) Arctagrostis arundinacea (Trin.) Beal var. arundinacea, 2n = 28, 2n = 29, and 2n = 30; (1b) Arctagrostis arundinacea (Trin.) Beal var. crassispica Bowden, 2n = 56; (1c) Arctagrostis latifolia (R.Br.) Griseb., 2n = 56. (2) Beckmannia syzigachne (Steud.) Fern., 2n = 14. (3) Brachyelytrum erectum (Schreb.) Beauv., two vars., 2n = 22. (4a) Bromus ciliatus L., 2n = 14; (4b) Bromus inermis Leyss., two subspecies and two vars., 2n = 56; (4e) Bromus kalmii A. Gray, 2n = 14; (4d) Bromus porteri (Coult.) Nash, 2n = 14; (4c) Bromus tectorum L., 2n = 14. (5) Catabrosa aquatica (L.) Beauv. var. laurentiana Fern., 2n = 20. (6) Dactylis glomerata L., 2n = 28. (7) Distichlisstricta (Torr.) Rydb., 2n = 40. (8a) Dupontiafisheri R.Br, subsp. fisheri, 2n = 132; (8b) Dupontia fisheri R.Br, subsp. psilosantha (Rupr.) Hultén, 2n = 44. (9) Eremopoa persica (Trin.) Roshev., 2n = 28. (10a) Festuca altaica Trin., 2n = 28; (10b) Festuca baffinensis Polunin, 2n = 28; (10c) Festuca brachyphylla Schultes, 2n = 42 and one collection, 2n = 44; (10d) Festuca elatior L., 2n = 14; (10e) Festuca obtusa Bieler, 2n = 42; (10f) Festuca prolifera (Piper) Fern. var. lasiolepis Fern., 2n = 50; (10g) Festuca rubra L., 2n = 42; (10h) Festuca saximontana Rydb., 2n = 42; (10i)Festuca scabrella Torr. ex Hook., two vars., 2n = 56 and 2n = 28. (11a) Glyceria borealis (Nash) Batchelder, 2n = 20; (11b) Glyceria canadensis (Michx.) Trin., 2n = 60; (11c) Glyceria grandis S. Wats., 2n = 20; (11d) Glyceria melicaria (Michx.) Hubb., 2n = 40; (11e) Glyceria pulchella (Nash) K. Schum., 2n = 20; (11f) Glyceria striata (Lam.) Hitchc, 2n = 20; (11g) Glyceria × gatineauensis Bowden (G. melicaria × G. striata), 2n = 30; (11h)Glyceria × ottawensis Bowden (G. canadensis × G. striata), three nothomorphs, 2n = 42, 2n = 46, and 2n = 48. (12) Lolium rigidum Gaud., 2n = 14. (13a) Phippsiaalgida (Sol.) R.Br., 2n = 28; (13b) Phippsia concinna (Th. Fries) Lindeb., 2n = 28. (14) Pleuropogon sabinei R.Br., 2n = 42. (15) Schizachnepurpurascens (Torr.) Swallen, 2n = 20. (16) Torreyochloa fernaldii (Hitchc.) Church, 2n = 14.
FUNGITOXICITY OF CHLORINATED HYDROCARBON INSECTICIDES IN RELATION TO WATER SOLUBILITY AND VAPOR PRESSURE
Authors: Richardson Lloyd T. , Miller D. M.
Published: August 2008

Fungitoxicity, in terms of inhibition of mycelial growth, was demonstrated with eight chlorinated hydrocarbon insecticides by the culture plate bio-assay method. All of the dosage–response curves thus derived were bimodal rather than linear. Evidence is presented to show that the shape of these curves is governed by two physical properties of the compounds: water solubility (which was determined experimentally) and vapor pressure. The concentration of insecticide in solution governs the initial rise of each dosage–response curve which is extended to a peak because of supersaturation and is followed by a decline as normal saturation is regained. The concentration of toxicant vapor in contact with the organism governs the second rise in the curve to a level dependent on the vapor pressure of the compound. Lindane has a high degree of fungitoxicity because of its relatively high water solubility. Heptachlor, chlordane, and aldrin are also highly toxic because of their vapor pressures. DDT, methoxychlor, dieldrin, and endrin are weakly fungitoxic because of both low water solubility and low vapor pressure.
VEGETATIVE PROPAGATION IN LINARIA VULGARIS
Authors: Bakshi Trilochan S. , Coupland Robert T.
Published: August 2008

Vegetative propagation in Linaria vulgaris is obtained by the development of numerous adventitious buds on its roots. Each bud originates exogenously on the parent root, and it is always associated with a lateral root which arises in the pericycle opposite a protoxylem point. Buds capable of vegetative propagation are not found on either the hypocotyl or the stem. This appears to be correlated with the absence in roots of the typical open type of lenticels and of any significant accumulation of starch. Soil disturbance seems to have a deleterious effect on the production of buds on roots.
A NEW GENUS IN PLANT RUSTS
Authors: Bakshi B. K. , Singh Sujan
Published: August 2008

The life history of Chrysomyxa piceae Barclay, the needle rust of spruce, Picea smithiana (Wall.) Boiss, has been worked out. The teliospores are one-celled, like Coleosporium, but germinate by external promycelia, like Chrysomyxa. The rust does not belong to either Coleosporium or Chrysomyxa or any other known genus and is named Ceropsora and described. It is allied to Mikronegeria, Chrysomyxa piceae Barclay becomes the type species of the new genus and is renamed as Ceropsora piceae (Barclay) Bakshi and Singh n. comb.
STUDIES ON RUBUS VIRUS DISEASES IN BRITISH COLUMBIA: VI. VARIETAL SUSCEPTIBILITY TO APHID INFESTATION IN RELATION TO VIRUS ACQUISITION
Authors: Stace-Smith Richard
Published: August 2008

Field populations of the large raspberry aphid, Amphorophora rubi (Kalt.), were observed for 4 years on 13 varieties of raspberry. Lloyd George and St. Walfried were immune, Malling Enterprise and Malling Promise were resistant, and the remainder were susceptible to infestation. Each variety was naturally infected with black raspberry necrosis virus. Vector studies demonstrated that this virus was acquired with difficulty from the immune varieties and also from the susceptible variety St. Regis, but was readily acquired from the remaining 10 varieties.
SOME EFFECTS OF SMELTER POLLUTION NORTHEAST OF FALCONBRIDGE, ONTARIO
Authors: Gorham Eville , Gordon Alan G.
Published: August 2008

A study along a line NNE. from the metal smelter at Falconbridge, Ontario, reveals that strong sulphate accumulation in the surface soil occurs only within about one mile of the chimneys emitting sulphur dioxide pollution while effects upon the soil drainage waters are marked to a distance of nearly two miles, and still clearly evident 10 or more miles away. The number of species present in the flora declines sharply within about four miles of the smelter, but certain species (e.g. Pinus strobus, Vaccinium myrtilloides) disappear at much greater distances. Among the most tolerant species are Acer rubrum, Quercus rubra, Sambucus pubens, and Polygonum cilinode.
THE CHLOROPHYLL CONTENT OF SOME NATIVE AND MANAGED PLANT COMMUNITIES IN CENTRAL MINNESOTA
Authors: Bray J. R.
Published: August 2008

Concentration of chlorophyll per unit area of land surface was measured for six forests and 13 native and managed herbaceous stands in central Minnesota. Chlorophyll samples were extracted in acetone and in ethyl ether, and spectro-photometric analysis made of chlorophyll a and b content. Wet and ovendry weights of the aboveground crop were determined.A highly significant correlation was found between the dry weight of the aboveground crop of the annual herbaceous stands and the chlorophyll content of these stands. All stable natural herbaceous stands had an approximately similar ratio of chlorophyll to the dry weight of aboveground parts.Chlorophyll content in grams per square meter of land surface along an upland gradient from field crop through native communities of increasing age or successional development or both was Zea mays (2.7), Soja max (0.9), younger to older successional stages of old field (0.3 to 0.6), native prairie (0.7), xeric (more open) savanna (0.6), mesic (less open) savanna (1.0), conifer–hardwood forest (3.1). Chlorophyll content for a pond hydrosere from the Nymphaea odorata margin through Carex lasiocarpa mat to Chamaedaphne calyculata shrub and Larix laricina forest increased from 0.3 to 1.4 g/m2. Values for a younger and older Populus tremuloides lowland grove were 1.7 and 5.9 and for a Typha marsh were 4.6 g/m2.These data showed a tendency for later successional stages to exceed earlier stages, for some lowland stands to exceed upland stands, for forest to exceed herbaceous communities on a given moisture level, and for field crops to exceed prairie and old field. The upland old field to forest sequence and the lowland Nymphaea to Larix sequence had similar chlorophyll contents for a given stage of successional development. There was a highly significant positive correlation between chlorophyll content and height of the arboreal stands, and a significant positive correlation between chlorophyll content and herbaceous stand height.A significant difference in chlorophyll content was found between all stands with three or more sample plots, except those with closely correspondent mean values. The maximum difference between stands was twentyfold, which does not support previous studies which have suggested a similarity of chlorophyll content in diverse communities.Chlorophyll concentrations and wet and dry weights per various plant parts are presented for the seven tree samples, and the presence of chlorophyll in other than leaf parts emphasized.
STUDIES OF VIRUS DISEASES OF STRAWBERRIES IN BRITISH COLUMBIA: III. TRANSMISSION OF STRAWBERRY VIRUSES BY APHIDS
Authors: Mellor F. C. , Forbes A. R.
Published: August 2008

Eleven aphid species commonly found on rosaceous plants were tested as vectors of eight strawberry viruses. Amphorophora rubi (Kalt.), Aphis rubifolii (Thomas), Aulacorthum solani (Kalt.), Macrosiphum rosae (L.), Myzus ascalonicus Doncaster, M. ornatus Laing, M. persicae (Sulz.), Pentatrichopus fragaefolii (Cock.), P. tetrarhodus (Walk.), and P. thomasi Ris Lambers transmitted the vein banding virus from one or both of two sources. P. fragaefolii, P. tetrarhodus, and P. thomasi transmitted mild mottle, while only P. fragaefolii and P. thomasi transmitted curly-dwarf mottle. M. rosae transmitted vein banding and possibly mild yellow edge. Aphis forbesi Weed failed to transmit any of the viruses tested. None of the species tested transmitted witches’ broom, crinkle, or strawberry latent-A virus.
THE LINKAGE MAP OF CHROMOSOME 2 OF THE TOMATO
Authors: Butler L.
Published: August 2008

The data accumulated over the past 30 years from the classification of some half a million plants are presented. It is shown that the mapping of chromosome 2, the former linkage group 1, presents many difficulties because of the lethal nature of Wo, and the reduced viability of ro, dv, and m. The problem of classification of o, bk, and ms10also presents difficulties. The examination of the monogenic ratios shows many of them to be disturbed because of lethality, viability, and misclassification, but these causes do not account for all the discrepancies. In the case of Wo and aw there are large excesses of the dominant class; this evidence along with data from anomalous recombination values indicates a chromosomal abnormality. It is suggested that this abnormality is a duplication which in some stocks gives two Wo loci about 25% apart, and two aw less than 40% apart, and also involves the loci of Me and Cu.The recombination values indicate that the map is dv 3 m 2 d 4 p 10 aw (psoro) 13 Me (Cubk) 4 Wo 2 ms105 s. The five genes within the brackets are in the positions indicated but the recombination values within each bracket are not known. While this linear order gives the best synthesis of the 61 recombination values, it also reveals several exceptions. The awps and awo values which should be less than 10% are 40%, and ps o which should be 3% is 26%. Significant differences of more than 10% are also registered between sets of data for the same pair of genes; this is another indication of chromosomal changes. The findings presented here should furnish a framework for more critical examination of specific sections of this linkage group.
THE INFLUENCE OF SMELTER FUMES UPON THE CHEMICAL COMPOSITION OF LAKE WATERS NEAR SUDBURY, ONTARIO, AND UPON THE SURROUNDING VEGETATION
Authors: Gorham Eville , Gordon Alan G.
Published: August 2008

Analyses for sulphate, calcium, and pH have been made on surface waters from 102 lakes and ponds in the Sudbury metal-smelting district, and data are presented for 35 of these. Sulphur pollution is frequently high within about 5 miles of the three smelters, many ponds exhibiting more than three times the sulphate concentration normal for this area, and three waters more than 10 times this level. Outside about 15 miles distance the influence of smelter pollution upon sulphate concentrations in surface waters is negligible. As expected, many of the most polluted waters are strongly acid, with pH values going as low as 3.3. Sulphuric acid from air pollution has also led to increased weathering of calcium from soils and rocks, so that this ion tends to rise in concentration not only in waters above pH 6 (as expected) but also in those below pH 5.Damage to terrestrial vegetation is frequently marked within about 5 miles of the smelters, while it is seldom obvious to the untrained eye beyond this distance. Severe damage occurs chiefly within about 2 miles of the smelters.
INDUCED SYNTHESIS OF PHLORIN-C14IN PELARGONIUM
Authors: Towers G. H. N. , Roy Chitra , Avadhani P. N.
Published: August 2008

Leaf disks of Pelargonium were shown to be capable of synthesizing phlorin-C14when administered phloroglucinol together with C14-labelled glucose, sucrose, or succinic acid. Changes with time in the distribution of radioactivity in phlorin and in sucrose in disks maintained on phloroglucinol and glucose-C14, in the light or in the dark, were followed. Phlorin-C14synthesis predominated in the dark and sucrose-C14synthesis in the light. The steady accumulation of phlorin with time suggests that it is not utilized metabolically. Labelled phlorin and sucrose were formed when succinate-1,4-C14or succinate-2,3-C14was administered in the light. Labelled hexoses were obtained with succinate-2,3-C14in the dark. Possible pathways for the conversion of succinate to sugars are suggested. In these experiments the synthesis of sucrose-C14from succinate-C14was reduced in the presence of phloroglucinol, concomitant with the formation of phlorin-C14.
DISTRIBUTION OF CANAVANINE IN THE FAMILY LEGUMINOSAE AS RELATED TO PHYLETIC GROUPINGS
Authors: Birdsong B. A. , Alston R. , Turner B. L.
Published: August 2008

The seeds of 161 species of legumes, representing 78 genera, were examined by chromatographic methods for canavanine content. The results are supplemented by data, variously collected, by other authors, to yield a total of 219 investigated species representing 109 genera. Of these, 68 species belonging to 32 genera have canavanine in their seeds.Canavanine has not been found in the subfamilies Mimosoideae or Caesalpinioideae. In the subfamily Papilionoideae it has not been found in the tribes Podalyrieae and Sophoreae. At least one species from each of the other tribes produces canavanine. In three genera, some species produce canavanine while others do not.These data are presumed to be of taxonomic significance and have been interpreted as support for chromosomal information indicating that the tribes Mimosoideae and Caesalpinioideae diverged relatively early from the "stem" line which is now represented by the Papilionoideae.
THE GENUS HETEROCHAETELLA
Authors: Luck-Allen E. Robena
Published: August 2008

Heterochaetella is retained as a separate genus to include three species. Heterochaete dubia Bourd. & Galz. is the type. Heterochaetella bispora, found on decayed wood in Ontario, is proposed as a new species. Heterochaetella brachyspora, treated as a variety of H. dubia by Bourdot and Galzin, is raised to specific rank. A redescription of the genus is given as well as descriptions and illustrations of the three species. Heterochaetella crystallina Bourd. is considered a synonym of Stypella papillata Möller and not congeneric with H. dubia.
A PALYNOLOGICAL STUDY RELATING TO THE PLEISTOCENE TORONTO FORMATION
Authors: Radforth N. W. , Terasmae J.
Published: August 2008

The present palynological study is used as a new approach to determine the stratigraphical and chronological position of the Pleistocene interglacial deposits, the Toronto formation, exposed in sections at Toronto, Ontario, Canada.An interpretation of lithology, combined with evidence supplied by the pollen and spore assemblages, indicates that the Don beds, the lower member of the Toronto formation, belong to the Sangamon Interglacial. The Scarborough beds, the upper member of the formation, were deposited during a nonglacial interval, cooler than the present. Conformity between the two members is questioned on grounds of lithological and palynological evidence.Results of palynological studies, as indicated by this investigation, can be used for interpretation of the mode of deposition of certain laminated sediments and for reconstruction of past types of landscape.
SUCROSE SYNTHESIS IN THE SEEDLING WHEAT LEAF
Authors: Ward G. M.
Published: August 2008

Glucose supplied as a metabolic substrate to excised wheat leaves by means of the vacuum infiltration technique is converted to sucrose. It has been shown that the rate of this conversion is not wholly referable to enzyme kinetics for the reaction is a complex physiological process. It is conditioned by numerous factors, being stimulated by high concentrations of substrate, by low temperature during incubation, by both high and low relative humidity, and being depressed by starvation. A new technique of first injecting and then withdrawing the substrate has indicated that the rate of cellular absorption of the substrate can be a limiting factor in the synthesis of sucrose.
A STUDY OF THE DISTRIBUTION OF CARBON-14 LABELLED COMPOUNDS IN STEM RUST INFECTED WHEAT LEAVES
Authors: Wang Dalton
Published: August 2008

Glucose-U-C14, glycine-2-C14, benzimidazole-2-C14, as well as C14O2, were fed to rusted leaves of Little Club wheat. Radioautographs of whole leaves gave similar results to those of previous investigators, indicating greater radioactivity in rust ed tissue sections. However, when quantitative measurements were made the results indicated that rusted tissue sections do not contain more radioactivity than the healthy tissue sections despite the apparent accumulation of labelled com pounds at infection sites indicated by radioautographs of the treated leaves. The apparent accumulation of radioactivity at the infection sites of rusted leaves may not, therefore, represent the actual concentration of the labelled compounds throughout the infected leaf. The phenomenon of radioactivity accumulation indicated by radioautographs may be attributed to two factors: (a) the geometric factor in respect to radioactive sources to the X-ray film and (b) the specific distribution in respect to the higher radioactivity in the rapidly growing regions of the fungus.
THE TAXONOMY AND HABITATS OF FUSARIUM SPECIES FROM TROPICAL AND TEMPERATE REGIONS
Authors: Gordon W. L.
Published: August 2008

The present taxonomic study involved approximately 1200 isolates of Fusarium which were received by the writer from time to time each year during the past 25 years from tropical and temperate regions. The various isolates originated in 59 geographic areas. Approximately 90% of the isolates were obtained from a total of 160 species of host plants which included cultivated and non-cultivated plants. The cultivated plants included the chief agricultural crops grown in tropical and temperate regions, respectively. About 10% of the isolates were obtained from miscellaneous habitats, e.g. soil, water, insects, wood pulp, fowl, dairy products, and human tissue.A total of 26 species, 4 varieties, and 17 formae of Fusarium, classified in 12 sections of the genus, were identified among the isolates. These species, varieties, and formae are: F. aquaeductuum (Radlk. & Rabh. pr.p) Lagh., F. dimerum Penz., F. merismoides Cda. (section Eupionnotes); F. decemcellulare Brick (section Spicarioides); F. nivale (Fr.) Ces. (section Arachnites); F. chlamydosporum Wr. & Rg., F. poae (Cda.) Sacc., F. sporotrichioides Sherb. (section Sporotrichiella); F. arthrosporioides Sherb., F. avenaceum (Fr.) Sacc. (section Roseum); F. semitectum Berk. & Rav. (section Arthrosporiella); F. acuminatum (Ell. & Everh.) Wr., F. compactum (Wr.) Gordon, F. equiseti (Cda.) Sacc, F. longipes Wr. (section Gibbosum); F. culmorum (W. G. Sm.) Sacc, F. graminearum Schwabe, F. heterosporum Nees emend. Raillo; F. sambucinum Fuckel, F. s. var. coeruleum Wr., F. s. forma 6 Wr., F. tumidum Sherb. (section Discolor); F. lateritium Nees, F. l. forma cajani (Padw.) Gordon, F. l. forma crotalariae (Padw.) Gordon, F. stilboides Wr. (section Lateritium); F. moniliforme Sheld., F. m. var. anthophilum (A. Br.) Wr., F. m. var. subglutinans Wr. & Rg. (section Liseola); F. oxysporum Schl. emend. Snyder & Hansen, F. oxysporum var. redolens (Wr.) Gordon; F. oxysporum forma callistephi (Beach) S. & H.; forma cepae (Hanz.) S. & H., forma dianthi (Prill. & Del.) S. & H., forma gladioli (Massey) S. & H., forma lini (Bolley) S. & H., forma lycopersici (Sacc.) S. & H., forma nicotianae (Johns.) S. & H., forma niveum (E. F. S.) S. & H., forma passiflorae Purss, forma pini (Hartig) S. & H., forma pisi (Lindf.) S. & H., forma tuberosi S. & H., forma vasinfectum (Atk.) S. & H. (section Elegans); F. coeruleum (Lib.) Sacc, F. solani (Mart.) App. & Wr. emend. S. & H. (section Martiella).As indicated by the number of geographic areas and habitats from which they were obtained, the six species most widely distributed were F. solani, F. oxysporum, F. equiseti, F. moniliforme, F. avenaceum, and F. semitectum. Five species, namely F. aquaeductuum, F. chlamydosporum, F. arthrosporioides, F. longipes, and F. tumidum, were encountered rarely, each being represented by a single isolate.
A DEVELOPMENTAL STUDY OF WILD RICE, ZIZANIA AQUATICA L.
Authors: Weir Cynthia E. , Dale Hugh M.
Published: August 2008

The life history of wild rice is traced from the appearance of the first submersed leaves in the spring until the seed of this annual plant is buried at the bottom of a lake in the fall. The characteristics of the three types of leaves are discussed. The change from the simple vegetative apex to the many-tipped, young inflorescence occurs early. Thus the potential yield in rice grains is determined as the tips of the upright leaves reach the surface of the water and before the stem elongates. The inflorescence develops acropetally as does each spikelet. Only at the later stages can the pistillate and staminate spikelets be distinguished. The development of the microspores and the nuclear changes in the embryo sac have been elucidated. In Zizania the embryo development has been found to be a variant of that found in Poa while the endosperm develops chiefly from the outside. A well-differentiated abscission layer develops at the base of each spikelet.
INFLUENCE OF MATERNAL TISSUE ON LOOSE SMUT INFECTION OF HYBRID BARLEY KERNELS
Authors: Loiselle R. , Shands R. G.
Published: August 2008

The influence of maternal tissues on loose smut (Ustilago nuda (Jens.) Rostr.) infection of hybrid tissues was investigated through histological studies of artificially inoculated kernels of susceptible and resistant varieties of barley and their reciprocal F1 hybrids. Depending on the stage of development of the kernel scanty to abundant mycelium was observed in the crease region, integument, aleurone, endosperm, and embryo of the susceptible kernels. In kernels of the resistant varieties, mycelium was not observed in the aleurone, endosperm, or embryo although present in the chalazal region and the parenchyma associated with the vascular bundle. After floret inoculation, the maternal tissues of F1 hybrid kernels of reciprocal crosses between the susceptible and resistant varieties had a mycelial development similar to that in the female parental varieties. Hybrid tissues of Odessa (susceptible) × Anoidium possessed a scanty mycelial development, whereas those of the reciprocal appeared to be free. Hybrid tissues of the reciprocal crosses between Odessa and Trebi had a scanty mycelial development. These observations indicated that maternal tissues influenced to some extent infection of the hybrid embryo. However, this influence appeared to be secondary in importance to that of the genotype of the embryo itself.
CYTOTAXONOMY AND INFRASPECIFIC VARIATION OF AGROPYRON SMITHII RYDB.
Authors: Gillett J. M. , Senn H. A.
Published: August 2008

Agropyron smithii Rydb. is considered to be the correct name of the grass commonly known as western wheat grass. The pubescent variety molle has been found to have no distinct geographical distribution within the species and is therefore reduced to the rank of form. Many of the eastern localities recorded are attributed to introduction rather than to extension of the species range. Characters of pubescence and awning show relative uniformity within the clone but a much wider variation over the entire range. Spike, spikelet, and floret pattern is compared with those of related species. Somatic chromosome counts on 62 plants from points throughout the range indicate constant octoploidy (2n = 56). Chromosomal rearrangements appear to be slight. The species does not cross with several other species tested and is apparently self-sterile.
AN INDOLEACETIC ACID 'OXIDASE' SYSTEM IN THE MYCELIUM OF MELAMPSORA LINI (PERS.) LEV.
Authors: Oaks Ann , Shaw Michael
Published: August 2008

Flax rust mycelium was grown on cotyledons of flax in a modified Knop's medium. The mycelium produced and apparently secreted a typical peroxidase-mediated indoleacetic acid 'oxidase'. Decarboxylation of radioactive indoleacetate (—C14OOH) was stimulated by Mn++ (10−4 and 10−3M), dichlorophenol (10−4M), and resorcinol (10−4M). Catechol (10−4M) and pyrogallol (10−4M) inhibited the reaction. Moreover, pyrogallol competitively inhibited the reaction in the presence of resorcinol. All four phenols increased oxygen uptake by the mycelium, catechol and pyrogallol being the most effective. Cu++ (10−3M) inhibited the reaction by 60%; cyanide (10−3M) and diethydithiocarbamate (2 × 10−4M) were almost completely inhibitory. The results are discussed briefly in relation to host–parasite interactions and the control of indoleacetic acid oxidase activity in vivo.
THE VEGETATION OF NORTHERN MANITOBA: VI. THE LOWER HAYES RIVER REGION
Authors: Ritchie J. C.
Published: August 2008

The vegetation of the Hudson Bay Lowlands of Canada is known only in the most superficial terms. This contribution provides descriptions of the chief cover types of a small portion of the Lowlands near the confluence of the Hayes and Nelson rivers. The area has a continental, subarctic climate. Postglacial marine inundation has deposited thick calcareous clays; the topography is flat.On the mineral substrata of alluvial and marine deposits the chief types of vegetation are salt marsh, shrub (dominated by Salix species), forests of Populus balsamifera, and forests of Picea glauca. They often form discrete zones in the order mentioned, and it is likely that this is a seral as well as spatial relationship. On the extensive peat substrata there are bog and fen types. In the former are distinguished two communities dominated by Picea mariana—one, termed lichen muskeg, with a ground layer of Cladonia and Ledum, and the other, moss muskeg, with Pleurozium and Ledum groenlandicum as ground layer dominants. Locally, areas of lichen muskeg have been destroyed by fire and are now occupied by willow communities. In wet inland areas, moss muskeg and lichen muskeg communities are associated with palsa and string-bog features. On shallower peats, usually nearer the shores and rivers, fens predominate, with Larix laricina and Betula glandulosa as the dominant phanerophytes.All these types have been distinguished on vertical aerial photographs, and their photographic characteristics are summarized. A detailed vegetation map illustrates their chorology.
SYNERGISM BETWEEN PRATYLENCHUS PENETRANS (COBB) AND VERTICILLIUM ALBO-ATRUM R. & B. IN EGGPLANT WILT
Authors: McKeen C. D. , Mountain W. B.
Published: August 2008

Studies conducted in steam-sterilized soil inoculated with Verticillium alboatrum and Pratylenchus penetrans demonstrated a synergistic relationship between fungus and nematode. At low and intermediate levels of Verticillium inoculum, the nematode increased wilt and the increase may be a function of the number of nematodes present. Except at the high inoculum levels of Verticillium, significantly larger numbers of P. penetrans occurred in eggplant roots in the presence than in the absence of the fungus. The nematode alone had no adverse effect on root condition or growth of eggplant.
PLANTGEOGRAPHICAL INVESTIGATIONS OF THE TUNDRA VEGETATION IN THE SOVIET UNION
Authors: Tikhomirov Boris A.
Published: August 2008

The tundra zone, including the forest tundra and the polar deserts, occupies about 15% of the entire surface of the U.S.S.R., or around 3 million square kilometers. If to this is added the area of open forests in the north, the territory covered will be about 35% of the Soviet Union. During the last decades, agriculture and stock raising have been introduced into the northern taiga and forest tundra, locally even into the tundra itself. It has therefore become necessary to study the northlands intensively from both the theoretical and practical viewpoints.Preliminary studies had already been done during the 18th and 19th centuries, beginning with Lomonosov and his school, and were followed by a series of expeditions by great naturalists to the north. The main research, however, took place after the October Revolution, and it was first devoted to the western parts of the tundra, but during the last decades it has spread to include also the eastern, Asiatic, parts.On the basis of theoretical research a number of flora manuals have been published, concerning the northern areas, and a series of detailed ecological maps have been edited.On the practical side, intensive investigations have been performed on natural pastures, especially with regard to reindeer management: the development and growth of the lichens have been studied and methods to utilize and improve them have been devised; air-reconnaissance has been used to establish the extent of pasture and meadow land; the biology of the northern plants has been studied, especially in connection with long-day and solifluction conditions; the ecological relationships of the plants in different associations have been worked out; the history and dispersal routes of the arctic flora have been established; and so on.On the basis of this practical knowledge of the tundra conditions, there is now a trend to utilize and improve arctic agriculture, e.g., to enlarge and improve pastures and meadow lands, and to plant trees on the parts suitable for afforestation.
DIEBACK OF BALSAM FIR IN ONTARIO
Authors: Raymond F L , Reid J
Published: August 2008

An outbreak of balsam fir dieback in Ontario, which was first reported in 1954, reached its peak throughout the Province in 1955 and gradually receded during subsequent years. The dieback, which involved leaders, branches, and occasionally entire trees, appeared when those parts died as the result of their proximal invasion by a fungus. Cankering usually accompanies necrosis; fruiting bodies may be produced immediately or may not appear until the spring following canker formation. The three fungi most commonly found in association with dieback, Thyronectria balsamea (Cke. & Pk.) Seel., Dermea balsamea (Pk.) Seav., and Valsa abietis Fr., were shown to be independently capable of inducing typical dieback and cankering when inoculated into wounds on transplanted trees. It was further shown that adult balsam fir borer beetles (Monochamus spp.), which regularly feed on and injure twigs and branches of healthy trees, usually carry viable material of one or more of the three common fungi. The ability of the beetles to kill twigs was confirmed and it was shown that, although dieback frequently develops from wounds made by fungus-infested beetles, no dieback ensued in the absence of fungi. The outbreak is believed to have been caused by the interaction of several factors (climate, fungi, site, and insects) on the host trees.
STUDIES OF LIGNIN BIOSYNTHESIS USING ISOTOPIC CARBON: IX. TAXONOMIC DISTRIBUTION OF THE ABILITY TO UTILIZE TYROSINE IN LIGNIFICATION
Authors: Brown Stewart A.
Published: August 2008

A survey of various plant species for the ability to utilize L-tyrosine as a lignin precursor has been extended, and the results obtained on a total of 21 species, representing seven families of monocotyledons and five of dicotyledons, are presented. Only grasses were able to convert L-tyrosine and L-phenylalanine to lignin with about equal efficiency, although two members of the Compositae and possibly one monocotyledon, Triglochin maritima, showed evidence of some ability to utilize tyrosine. One species of Juncus, J. nodosus, was unable to use phenylalanine efficiently and another, J. balticus, yielded conflicting results with regard to the utilization of both compounds. The findings are discussed in relation to known lignification pathways and taxonomic relationships.
STIMULATION BY LIGHT OF SPORULATION IN TRICHODERMA LIGNORUM (TODE) HARZ
Authors: Miller J. J. , Reid James
Published: August 2008

Exposure of growing cultures to white light caused subsequent formation of a ring of conidia-bearing mycelium at the location occupied by their advancing margins at the time of irradiation. Violet and blue light were very effective in stimulating sporulation, green was less so, and yellow and red were ineffective. An exposure to white light of the order of 1 foot-candle for 1 minute sufficed to initiate the sporulation response.
FURTHER EVIDENCE OF THE RELATION BETWEEN 2-DESVINYL-2-FORMYL-CHLOROPHYLL-aAND CHLOROPHYLL-d
Authors: Holt A. Stanley
Published: August 2008

2-Desvinyl-2-formyl-chlorophyll-a (made by permanganate oxidation of chlorophyll-a) and chlorophyll-d (isolated from Gigartina papillata) were compared. They possessed identical visible absorption spectra, formed reduction derivatives with identical spectra, and chromatographed as a single zone on a sugar column. These results provide further evidence that chlorophyll-d is 2-desvinyl-2-formyl-chlorophyll-a. Certain thalli of G. papillata yielded chlorophyll-d while others yielded none. All thalli of Rhodomela larix yielded chlorophyll-d but in extremely small amounts.
CHLOROPHYLL DERIVATIVES, SULPHUR, AND CARBON IN SEDIMENT CORES FROM TWO ENGLISH LAKES
Authors: Gorham Eville
Published: August 2008

Chlorophyll derivatives, sulphur, and carbon exhibit similar trends in each of two sediment cores, one from the fertile Esthwaite Water and the other from the unproductive Ennerdale Water. In Esthwaite Water maximum levels of all three constituents were reached early in the course of lake development, while in Ennerdale Water maxima were attained much later, and, in the case of chlorophyll derivatives and sulphur, were much lower than in Esthwaite. Relatively high optical densities of acetone extracts between 400 and 500 mμ suggest the presence of carotenoids in surface muds from Esthwaite Water. Much lower optical densities were recorded for this wave-length range in extracts of deeper sediments from Esthwaite and all sediments from Ennerdale. Low ratios of optical density at 410 mμ to density at 350 mμ are characteristic of surface sediments from infertile lakes such as Ennerdale Water, and of woodland soils. However, higher ratios near to those observed throughout the Esthwaite core were found in the deeper Ennerdale sediments, with the exception of the deepest sample.Ratios of chlorophyll derivatives to carbon and of sulphur to carbon were higher in the more fertile Esthwaite Water, although relatively low ratios during the earliest stages of development indicate that this lake may have been less fertile then. In Ennerdale Water the ratio of chlorophyll derivatives to carbon exhibited a much slower rise to maximum values than in Esthwaite, and these maxima were much the same as the early Esthwaite minima. The ratio of sulphur to carbon was also consistently lower in Ennerdale Water.
GROWTH INHIBITION OF TWO SAPROPHYTIC AND TWO PLANT PARASITIC SOIL FUNGI BY ANTIBIOTICS
Authors: Ward E. W. B. , Henry A. W.
Published: August 2008

Comparisons were made of growth inhibition of two saprophytic (Trichoderma viride, Trichocladium asperum) and two plant parasitic soil fungi (Ophiobolus graminis, Fomes annosus) by antibiotics. The fungi were grown on an agar medium containing various concentrations of one of the antibiotics: acti-dione, gliotoxin, griseofulvin, patulin, or trichothecin. In general the two parasites tended to be more sensitive than the saprophytes, but there were several individual exceptions. Moreover, the comparative responses of the fungi at different antibiotic concentrations were frequently not proportionately related. The results are discussed in relation to the possible effects of antibiotics on fungi in natural soil.
NEW GENES FOR RESISTANCE TO RACES OF OAT STEM RUST
Authors: Welsh J. N. , Green G. J. , McKenzie R. I. H.
Published: August 2008

The inheritance in oats of reaction to some new races and to some well-known races of oat stem rust, Puccinia graminis Pers. f. sp. avenae Erikss. and Henn., was investigated in the crosses Jostrain × Eagle, Canuck × Cherokee, and R.L. 524.1 (Hajira × Banner) × Eagle. The resistance of the variety Jostrain to races 1, 3, 4, 13, and 13A was conferred by a single gene, here designated as the E gene in accordance with the practice of designating genes for stem rust resistance by capital letters. Canuck, a derivative of Jostrain, carries the new E gene and the previously identified B gene. The resistance of R.L. 524.1 to all races is conferred by two major genes and a modifying gene. One of the major genes acts like the well-known B gene which confers resistance to all races except 6A, 7A, 8A, and 13A. The other major gene apparently is a new gene in oats for resistance to stem rust and is here designated the F gene. The F gene confers resistance to all races but a modifying gene is required along with it for resistance to race 7.
A CLOSED-CIRCUIT APPARATUS WITH AN INFRARED CO2 ANALYZER AND A GEIGER TUBE FOR CONTINUOUS MEASUREMENT OF CO2 EXCHANGE IN PHOTOSYNTHESIS AND RESPIRATION
Authors: Lister G. R. , Krotkov G. , Nelson C. D.
Published: August 2008

An apparatus is described which permits continuous monitoring of the concentration of both the total and radioactive carbon dioxide around an experimental plant. The apparatus consists of a closed circuit of tubing into which are introduced a plant chamber, an infrared CO2 analyzer, a Geiger tube, and a pump. Continuous records are obtained rom which are calculated the amounts of total carbon dioxide and C14 absorbed or evolved by a plant. With an apparatus 2.03 liters in volume, evolution or absorption of amounts of CO2 as small as 0.01 mg were measured. The time necessary to observe a change in the concentration of C14 in the chamber (i.e. the lag time) is less than 2 seconds. The corresponding value for the total carbon dioxide is 7 seconds.Experiments on the respiration and photosynthesis of detached shoots of Pinus resinosa in an atmosphere containing C14O2 are described as an example of the use of the apparatus. The external C14O2 was continuously diluted with C12O2 in both light and dark. However, evolution of carbon dioxide in the light (light respiration) was only about 20% of that in the dark (dark respiration).
SOME EFFECTS OF POTASSIUM DEFICIENCY ON THE METABOLISM OF THE TOMATO PLANT
Authors: Jones L. H.
Published: August 2008

The organic and keto acid levels in the leaves of tomato plants grown with varying levels of potassium were examined. As the potassium level was reduced, the levels of malic, oxalic, and sometimes pyruvic acids decreased, while citric, α-ketoglutaric, and glyoxylic acids accumulated. Total organic acids remained almost constant at all potassium levels, while such changes as occurred in cation levels were balanced by phosphate. These relationships held for plants grown under widely different environmental conditions and were not affected by the age of the plants. It is suggested that the changes in acid balance were brought about by changes in the activity of enzymes concerned in pyruvate metabolism and by shifts in equilibrium caused by free amino acids and amides accumulated as a result of deranged protein metabolism.
THE INTERACTION OF PLANT, PATHOGEN, AND SCAPTOCORIS TALPA CHAMP
Authors: Timonin M. I.
Published: August 2008

The effects of the odoriferous volatile matter produced by Scaptocoris talpa Champ on the activity of Fusarium oxysporum f. cubense (E.F.S.) Sny. and Hans., F. oxysporum f. lycopersici (Sacc.) Sny. and Hans., and Meloidogyne incognita in soil, and its phytotoxicity to tomato seedlings, were investigated.The results obtained indicated that 50–75 insects per pot protected tomato seedlings (Bonny Best) and banana plants (Gros Michel) from attack by their respective fungus pathogens and one insect per 2 grams of soil protected tomato seedlings from attack by root-knot nematode.The apparatus especially constructed to study the phytotoxicity of odoriferous volatile matter to tomato seedlings and its effect on microbial population of the soil was described. By means of this apparatus it was found that 6 days of a weak flow of a mixture of air and volatile matter produced by 350–400 insects was not phytotoxic to six tomato seedlings. Furthermore, it was also found that volatile matter produced by 800 insects, under the same conditions, was not toxic to one tomato seedling. Under similar conditions the non-phytotoxic concentration of volatile matter produced by 350–400 insects reduced the density of F. oxysporum f. cubense population in soil samples containing 25 and 15% (w/w) of moisture by 61.20 and 45.78% respectively.It was also demonstrated that one insect per 2 grams of soil infested with the root-knot nematode during 16 hours' incubation produced a nematocidal concentration of volatile matter.The possibility of selective toxicity of volatile odoriferous matter to various bacteria is also discussed.
THE EFFECT OF CERTAIN ELEMENTS, WITH EMPHASIS ON NITROGEN, ON THE PRODUCTION OF PERITHECIA OF VENTURIA INAEQUALIS (CKE.) WINT.
Authors: Ross R. G.
Published: August 2008

Various elements were tested for their effect on the formation of perithecia of Venturia inaequalis. Apart from nitrogen the elements tested had little effect on the formation of perithecia except at relatively high concentrations. Perithecia did not form in media containing low concentrations of nitrogen and this was influenced by the source of nitrogen and by the cation present in nitrate salts. Perithecial initials developed in higher nitrogen concentrations than perithecia. Nitrogen added 9 weeks after mating of two lines of the fungus prevented the formation of perithecia.Results were difficult to reproduce in a potato-dextrose apple leaf decoction medium but reproducible results were obtained in a synthetic medium.
MECHANISMS CONTRIBUTING TO THE ERADICATION OF SPORES OF HELMINTHOSPORIUM SATIVUM FROM AMENDED SOIL
Authors: Chinn S. H. F. , Ledingham R. J.
Published: August 2008

Declines in population of spores of Helminthosporium sativum in amended soil were due to disappearance that occurred in normal soil and to eradication brought about by the germination–lysis mechanism and by an increase in antagonism. Germination–lysis played a major role in molasses- and vitamin C-amended soils but not in glucose-amended soil, as was evidenced by the density of spore populations in the soils at intervals over a 16-week period.Antagonism which was increased in all three amended soils was responsible to a lesser extent for the eradication of the spores. The data suggest that antagonism was more effective during the early, than during the later, stages in the breakdown of the amendment. A close correlation was noted between spore population and the incidence of seedling infection. Correlation between spore population and disease ratings was much less significant.
GENETICS OF PHYTOPATHOGENIC FUNGI: VI. HETEROCARYONS INVOLVING GIBBERELLA FUJIKUROI AND FORMAE OF FUSARIUM OXYSPORUM
Authors: Dhillon T. S. , Garber E. D. , Wyttenbach Ellen G.
Published: August 2008

Heterocaryons involving nutritionally deficient mutant strains of Gibberella fujikuroi and mutant strains of this species and of four formae of Fusarium oxysporum were obtained. It was not possible to get heterocaryons of G. fujikuroi and F. oxysporum f. pisi until the latter mutant strain was adapted to grow on minimal medium. Spores from heterocaryons had either the genotype of only one component strain or of either component strain, depending on the heterocaryon. It was possible to alter nuclear ratios by growing certain heterocaryons on minimal medium supplemented with the compound(s) required by one or the other component strain. Sectors from certain heterocaryons grown on potato dextrose agar were homocaryotic for the nutritional requirement(s) of one component strain. Heterocaryosis as a taxonomic tool and the difficulties involved in demonstrating the parasexual cycle in the genus Fusarium are discussed.
FACTORS AFFECTING BRANCH INFECTION IN ASPEN
Authors: Etheridge D. E.
Published: August 2008

Comparative studies have shown that branch infections are almost twice as frequent in aspen (Populus tremuloides Michx.) in mesic sites as in trees of similar ages in dry sites. This has been attributed to: (1) the proneness to infection of young dead branches, and (2) the greater mortality of young branches in mesic sites. No difference was found between the two sites with respect to the pattern of air temperature and relative humidity. The moisture content of dead branches was influenced to a minor extent by site, but only after considerable rain had fallen did branch moisture reach a level favorable for infection by fungi. Although several species of imperfect fungi and bacteria infected aspen branches from 4 years following mortality, wood-destroying fungi, namely Corticium polygonium Pers. and Polyporus adustus (Willd.) Fr., did not appear until 7 and 8 years after the death of branches. After 19 years, decay of Fomes igniarius (L. ex Fr.) Kickx. occurred in branches only as lateral extensions of heartwood infection. The feasibility of artificial pruning to reduce the risk of heart rot infection in young aspen stands is discussed.
HYPHOMYCETES OF CONIFER LEAF LITTER: THYSANOPHORA GEN. NOV.
Authors: Kendrick W. Bryce
Published: August 2008

A new genus, Thysanophora, based on Haplographium penicillioides Roum., is proposed. Two species are placed within the genus: Thysanophora penicillioides (Roum.) Kendrick comb. nov. is redescribed from 32 collections and isolations, and Thysanophora longispora Kendrick sp. nov. is described from four collections on decaying needles of Tsuga canadensis and an isolation derived from one of these collections.
HYPHOMYCETES OF CONIFER LEAF LITTER: HORMODENDRUM STAUROPHORUM SP. NOV.
Authors: Kendrick W. Bryce
Published: August 2008

Hormodendrum staurophorum sp. nov., a pleomorphic dematiaceous hyphomycete isolated from fallen needles of Pinus sylvestris, is described and illustrated.