bluuebunny/crossref_metadata_2025 huggingface dataset:
GROWTH OF THE RUST FUNGUS PUCCINIA HELIANTHI ON TISSUE CULTURES OF ITS HOST
Authors: Nozzolillo Constance , Craigie J. H.
Published: August 2008

Rust-infected cotyledon, hypocotyl, and stem sections of sunflower seedlings were cultured on nutrient agar media. Callus growth from cotyledon sections was negligible, but hypocotyl and stem sections proliferated more or less freely. Infections arising from basidiospores produced an abundant tuft-like growth of haploid surface mycelium. Infections arising from urediniospores lacked almost entirely surface mycelial growth, but produced urediniospores in abundance, and finally teliospores.Copious aeciospore production occurred in some cultures where two basidiospore infections of different mating types coalesced. Later such compound infections produced urediniospores and teliospores. Tufts of mycelium developed on the new callus growth of some cultures. One of these calluses (examined cytologically) contained a number of more or less subnormal pycnia and aecia in different stages of development. Only a few sections produced callus tissue capable of surviving repeated subculturing. In the fourth set of subcultures from one such section, rust mycelium appeared as tufts on six of the calluses.
OBSERVATIONS ON CEREAL EMBRYOS IN RELATION TO THE "EMBRYO TEST" FOR LOOSE SMUTS
Authors: Russell R. C.
Published: August 2008

The embryos of wheat, barley, oats, and rye may be distinguished readily by differences in the shape of the scutella and by the relative sizes of the root initials. Photomicrographs of transverse sections of a wheat embryo show that the embryonic leaves within the coleoptile are arranged alternately, the first one facing towards the scutellum. Their edges are curled around the growing point and meet on the opposite side of the cavity in the coleoptile. A structure, referred to as a "pad", covers the side of the embryo facing the endosperm.Abnormalities found in whole barley embryos include the dormant mycelium of loose smut which appears as brown threads mainly in the surface tissues of the scutellum. Frost, occurring during the later development of the kernel, causes a stunting of the embryo, particularly of the coleoptile, and the production of small particles of yellowish-brown pigment in the tissues of the embryo. Other abnormalities are figured and discussed.
COCHLIOBOLUS SATIVUS: III. EFFECT OF ULTRAVIOLET RADIATION
Authors: Tinline R. D. , Stauffer J. F. , Dickson J. G.
Published: August 2008

The lethal and mutagenic effect of ultraviolet light on two isolates of Cochliobolus sativus was studied. Conidia of a dark-spored strain were considerably more resistant to high doses of radiation than those of a white-spored strain. Ultraviolet radiation increased the frequency of mutation in the fungus. Mutants were recovered that differed from their parents in degree of sporulation, rate of growth, pigmentation, amount of aerial mycelium, topography and consistency of colony, and pathogenicity to wheat seedlings. Tetrads from crosses between weakly and highly pathogenic strains indicated that pathogenicity was not a clearly segregating character.
FACTORS AFFECTING SUBSEQUENT GERMINATION OF CEREAL SEEDS SOWN IN SOILS OF SUBGERMINATION MOISTURE CONTENT
Authors: Wallace H. A. H.
Published: August 2008

Seeds of wheat sown in soils of subgermination moisture content sometimes decay and die. The critical moisture content at which maximum seed decay occurs is at a level approximately equal to one-half the difference between air-dry soil and soil moist enough for seed to germinate. The relationship apparently holds irrespective of soil type, even though the actual moisture percentage of different soil types at the critical level is quite distinct. “Dry” soil as used in these studies refers to air-dry soil with 8% moisture added. The subsequent germination of wheat was reduced after 3 days' incubation in “dry” soil at 30 °C, and 14–20 days at 5 °C. Germinability was reduced in strongly saline soil. Different samples of wheat varied greatly in germinability after incubation in “dry” soil. Sterilizing the “dry” soil did not change its effect on germination of various seed lots.Much of the variation in loss of germinability was correlated with thresher injuries to the seed coat. Wheat, rye, and hull-less varieties of oats and barley, especially with seeds of more than standard weight per bushel, are susceptible to thresher injury. Growth cracks, sprouting, and frost injury all affect germination adversely. Cereal seeds with hulls, or with high moisture content, or below standard weight, or of small size, and wheat without projecting embryos, are less susceptible to thresher injury, and to consequent reduction of germinability.The “field” fungi Alternaria sp. and Helminthosporium spp. grew out of cereal seeds plated on potato-sucrose agar or moistened filter paper and from germinated seeds grown in “moist” soil. After incubation in “dry” soil germinating seeds gave rise to Alternaria, but not to Helminthosporium spp. The non-germinating seeds from “dry” soil were infected by “storage” fungi, e.g. Penicillium, Aspergillus, Rhizopus, and Mucor. The “storage” fungi do not usually infect cereal seeds sown in “moist” soil, but in “dry” soil both sound and injured seed can be infected. The infection of sound seed is slow, permitting the seed to germinate, but injured seed is infected rapidly and does not germinate. The “storage” fungi invade seeds already infected by “field” fungi and inhibit the growth of the latter.All samples of treated and untreated wheat seed sown in “moist” soil gave good germination. After incubation in “dry” soil the germination of treated seed was fair to good, and of untreated seed was poor to good. Treatment with formalin before incubation in “dry” soil doubled the germination; treatment with Ceresan M, Half-ounce Leytosan, and a water soak trebled germination compared with the untreated check. However, the best treatment in “dry” soil gave 31% less germination than the untreated check sown in “moist” soil. Under “dry” soil conditions a sound seed coat appears to provide better protection against seed-decaying organisms than any seed treatment tested.
CYTOLOGICAL STUDIES IN THE GENUS ERIGERON
Authors: Montgomery F. H. , Yang Shung-Jun
Published: August 2008

The literature relating to the chromosome numbers in the genus Erigeron has been reviewed, and all reported numbers are given. The chromosome number for E. breweri var. porphyreticus (Jones) Cronquist, 2n = 18; E. divergens var. cinereus A. Gray, 2n = 27; E. glabellus var. glabellus Cronquist, 2n = 36; E. glabellus var. pubescens (Hook.) Cronquist, 2n = 36; E. hyssopifolius Michx., 2n = 18; E. quercifolia Lam., 2n = 36; E. simplex Greene, 2n = 27; E. strigosus var. beyrichii (Fisch. & Mey.) A. Gray, 2n = 27; and E. vernus T. & G., 2n = 18 are new determinations. Different numbers from those previously reported have been found for E. pulchellus Michx., 2n = 27, and E. strigosus (Muhl.) Willd., 2n = 36. Chromosome counts over a large area of their distribution have been made for E. annuus (L.) Pers., E. pulchellus Michx., E. philadelphicus L., and E. strigosus (Muhl.) Willd.
THE PHYSIOLOGY OF HOST–PARASITE RELATIONS: VI. OXIDATION–REDUCTION CHANGES IN WHEAT LEAF SAP CAUSED BY RUST INFECTION
Authors: Kaul Rudolf , Shaw Michael
Published: August 2008

Extracts of healthy and rusted leaves of Little Club and Khapli wheats were made under anaerobic conditions. Oxidation–reduction potentials in the extracts were measured at two different levels both in the presence and in the absence of both methylene blue and riboflavin as redox mediators. At the lower level (i.e. in the absence of mediators) a reversible rise in potential was noted during the course of rust infection on Little Club; with Khapli the rise was similar but was not reversed. The response to rust infection of resistant and susceptible plants was also reflected in characteristic changes in the average potentials at higher levels (i.e. in the presence of mediators). After infection the oxidation–reduction balance of susceptible tissue was reorganized by the introduction of new systems which were found in the reduced state only. After infection the oxidation–reduction potential of resistant tissue was only poorly poised as indicated by a rise in the average potentials and as demonstrated by oxidation– reduction titrations.The results are discussed and the possibility is considered that a rust-induced catalyst may “short circuit” the chain of hydrogen transport, thus initiating all the observed redox changes.
STUDIES IN SAXIFRAGACEAE: III. SAXIFRAGA ODONTOLOMA AND LYALLII, AND NORTH AMERICAN SUBSPECIES OF S. PUNCTATA
Authors: Calder J. A. , Savile D. B. O.
Published: August 2008

The taxonomy and phytogeography of Saxifraga odonloloma (S. argula auct.), S. lyallii, and S. punctata are presented. S. odonloloma is not closely related to S. punctata but is much more closely allied to S. lyallii with which it hybridizes. S. lyallii is divided into two varieties, var. lyallii near the 49th parallel, and var. hultenii var. nov. from Alaska to southern B.C. S. punctata is divided into six subspecies in North America: sspp. nelsoniana (D. Don) Hult., insularis Hult., pacifica Hult., carlottae ssp. nov., cascadensis ssp. nov., and porsildiana ssp. nov.
FUNGI AND DECAY IN ASPEN AND BALSAM POPLAR IN THE BOREAL FOREST REGION, ALBERTA
Authors: Thomas G. P. , Etheridge D. E. , Paul Glen
Published: August 2008

Examination of 835 living trembling aspen (Populus tremuloides Michx.) and 527 balsam poplar (Populus balsamifera L.) on 47 sample plots of mixed-wood forest of the Boreal Forest Region, Alberta, showed 73% of the aspen and 61% of the balsam poplar to be decayed. Additional trees of both species were infected by stain-producing fungi. The incidence of infection in aspen decreased from mesic sites to dry sites, while that for balsam poplar was about the same in mesic and wet sites. Fomes igniarius (L. ex Fr.) Kickx was the first ranking fungus in both hosts in terms of associated decay. It had the greatest incidence of all fungi in aspen but ranked third to Pholiota spectabilis (Fr.) Quél. and Polyporus aduslus Willd. ex Fr. in balsam poplar. Corticium polygonium Pers. and Radulum casearium (Morg.) Lloyd together caused about as much decay in aspen as did Fomes igniarius, although neither fungus occurred in balsam poplar. Contrary to its generally low incidence in balsam poplar, Pholiota destruens (Brond.) Quél. caused most of the decay in this host, excepting that ascribed to Fomes igniarius. Pholiola destruens did not occur in aspen. Many fungi caused both basal and stem infections in both hosts, while few caused infections of one type only. Armillaria mellea (Vahl ex Fr.) Quél. caused the greatest number of basal infections in aspen but was exceeded by Pholiota spectabilis in balsam poplar. The greatest amount of butt decay was ascribed to Phlebia strigosozonala (Schw.) Lloyd in aspen and to Pholiota spectabilis in balsam poplar. The overall losses of volume due to decay were 25% and 10%, respectively, for aspen and balsam poplar.
INHIBITION OF RUST DEVELOPMENT ON DETACHED WHEAT LEAVES BY METABOLITES, ANTIMETABOLITES, AND ENZYME POISONS
Authors: Samborski D. J. , Forsyth F. R.
Published: August 2008

The effect of metabolites and antimetabolites on rust development was studied, using detached leaves of Little Club wheat floated on solutions containing benzimidazole plus the compound under study. Purines and pyrimidines, vitamins, amino acids, carbohydrates, and enzyme poisons were tested. A number of these compounds inhibited leaf and stem rusts of wheat at concentrations that were not injurious to the host. Of the purines and pyrimidines that were tested, thymine and the analogue azathymine were the only effective inhibitors. The antivitamin oxythiamine was inhibitory and the inhibition was competitively reversed by thiamine.A few natural amino acids, notably histidine, isoleucine, methionine, and serine, inhibited rust development. The inhibition was reversed by glycine in all cases except with serine. Amino acid analogues, particularly canavanine, ethionine, and p-fluorophenylalanine, were excellent inhibitors; the inhibitions were reversed by comparable levels of arginine, methionine, and phenylalanine respectively. The carbohydrates lyxose, xylose, sorbose, and all the sugar alcohols tested were effective inhibitors of rust development. Of the enzyme poisons tested, sodium fluoride and sodium azide differentially inhibited rust growth.
CHROMOSOME NUMBERS AND TAXONOMIC NOTES ON NORTHERN GRASSES: III. TWENTY-FIVE GENERA
Authors: Bowden Wray M.
Published: August 2008

Chromosome numbers and voucher specimens are recorded for some collections of 25 genera of grasses, mainly collected in Canada. The somatic chromosome numbers of the following are recorded: (1) Agrostis borealis, 2n = 56; A. canina, 2n = 14; A. gigantea, 2n = 42; A. palustris, 2n = 30; A. perennans, 2n = 42; A. scabra, 2n = 42; and A. tenuis, 2n = 28; 32; and 34. (2) Alopecurus acqualis, 2n = 14; A. alpinus, 2n = 105; 112; and 119; A. geniculatus, 2n = 28; A. occidentalis, 2n = 112; and A. pratensis, 2n = 28. (3) Ammophila breviligulata, 2n = 28. (4) Anthoxanthum odoratum, 2n = 20. (5) Calamagrostis canadensis, 2n = 42; and 56; C. inexpansa, 2n = 70; C. lapponica, 2n = 28; 32; 42; ca. 91; 98; and 140; C. neglecta, 2n = 28; C. pickeringii, 2n = 28; C. purpurascens, 2n = 28; 42; and 84; and Calamagrostis sp.?, putative hybrid, 2n = 49. (6) Cinna arundinacea, 2n = 28; and Cinna latifolia, 2n = 28. (7) Danlhonia compressa, 2n = 36; and D. spicata, 2n = 36. (8) Deschampsia brevifolia, 2n = 26; D. caespitosa, 2n = 26; 27; and 28; D. elongata, 2n = 26; D. flexuosa, 2n = 28; and 32; and D. pumila, 2n = ca. 39. (9) Hierochloë alpina, 2n = 56; and H. odorata, 2n = 56. (10) Koeleria cristata, 2n = 14. (11) Leersia virginica, 2n = ca. 48. (12) Milium effusum, 2n = 28. (13) Muhlenbergia squarrosa, 2n = 40; and M. uniflora, 2n = ca. 42. (14) Nardus stricta, 2n = 30. (15) Oryzopsis asperifolia, 2n = 48; O. pungens, 2n = 24; and O. racemosa, 2n = 48. (16) Panicum xanthophysum, 2n = 36. (17) Phalaris arundinacea, 2n = 28. (18) Phleum alpinum, 2n = 28; and Phleum pratense, 2n = 42. (19) Sieglingia decumbens, 2n = 36. (20) Sorghastrum nutans, 2n = 40. (21) Spartina gracilis, 2n = 42. (22) Sphenopholis intermedia, 2n = 14. (23) Sporobolus cryptandrus, 2n = 36. (24) Stipa comata, 2n = 44. (25) Trisetum flavescens, 2n = 28; T. molle, 2n = 42; and T. spicalum, 2n = 28.
EFFECT OF PHOTOPERIOD ON DROUGHT RESISTANCE OF WHITE SPRUCE SEEDLINGS
Authors: Vaartaja O.
Published: August 2008

Seedlings of Picea glauca were grown for 2 months under three photoperiodic treatments. Short day treatment induced early terminal dormancy and resistance to severe drought treatment. Long day treatments, on the other hand, allowed prolonged growth of most seedlings and made them susceptible to drought.
INTERRELATIONSHIPS BETWEEN PLANT AGE, ROOT-ROT INFECTION, AND COLD HARDINESS IN WINTER WHEAT
Authors: Andrews J. E. , Horricks J. S. , Roberts D. W. A.
Published: August 2008

The effect of plant age and root rot caused by Bipolaris sorokiniana and Fusarium culmorum on the cold hardiness of winter wheat and the effect of cold injury on root-rot infection were studied during 3 years at Lethbridge, Alberta. The oldest and youngest plants were less cold hardy than those of an intermediate age. Root-rot damage predisposed plants to cold injury and, in turn, cold injury predisposed plants to root-rot damage. Winter wheat inoculated with B. sorokiniana and F. culmorum and seeded at the earliest dates had recovered from infection before exposure to the freezing treatment and, apparently because of delayed development, was more cold hardy than uninoculated wheat seeded on the same date. Results from cold-chamber and field studies indicated that the severe root-rot damage often observed in nearly mature winter wheat seeded early the previous year is not a direct result of heavy infection at or near the time of seeding but is secondary to winter injury that often occurs in early-seeded winter wheat.
GROWTH AND METABOLISM OF ASPERGILLUS NIDULANS EIDAM ON DIFFERENT NITROGEN SOURCES IN SYNTHETIC MEDIA CONDUCIVE TO FAT FORMATION
Authors: Naguib Kaiser , Saddik Kamel
Published: August 2008

Aspergillus nidulans has been grown in surface culture on high-sugar media favorable for fat formation and containing, as nitrogen source, sodium nitrate, ammonium chloride, or asparagine. Growth, sugar and nitrogen uptake, and syntheses of carbohydrates, proteins, and fat were all followed over an incubation period of 20 days. In the early stages, growth was influenced by the nature of the nitrogen source, being highest on asparagine and lowest on ammonium chloride, with the same sugar uptake. Later, dry weight increase proceeded at a high rate on asparagine, at a moderate rate on sodium nitrate, and it almost stopped on ammonium chloride, where the pH dropped to a very low value. At this stage, increase in dry weight followed sugar absorption, and was due to accretion of non-nitrogenous compounds.Asparagine media were by far superior to nitrate or ammonium media for fat formation. Protein and carbohydrate contents were higher in nitrate- than in asparagine- or ammonium-fed mycelial felts. All synthetic processes almost stopped in ammonium cultures after the early growth phase. It seems that the attitude of the fungus towards ammonium nitrogen could not be fully manifested due to restricted growth, and therefore it is suggested that no definite conclusions with regard to ammonium utilization by Aspergillus nidulans can be drawn unless the pH of the medium is controlled and growth on ammonium nitrogen made possible.
IODOACETATE INHIBITION OF PHOTOSYNTHETIC CARBON DIOXIDE ASSIMILATION IN SUGAR BEET AND SOYBEAN LEAVES
Authors: Mortimer D. C.
Published: August 2008

When the petioles of freshly excised sugar beet or soybean leaves were immersed in dilute iodoacetate solutions, the rates of photosynthetic carbon dioxide assimilation were reduced and characteristic changes in the distribution of assimilated C14were observed. Inhibited sugar beet leaves accumulated C14in phosphoglyceric acid (PGA) and aspartic acid, but did not incorporate C14into glyceric acid. Inhibited soybean leaves continued to form glyceric acid, but did not incorporate C14into PGA and only trace amounts into aspartic acid. Incorporation of C14into sucrose by the sugar beet leaf ceased when the assimilation of carbon dioxide was reduced below 1/10th of normal, while soybean leaves still formed sucrose at that level of inhibition. It was concluded from these and other data that the mechanisms for photosynthetic carbon dioxide assimilation in the two species were different. The iodoacetate-sensitive, PGA-glyceraldehyde-3-phosphate reduction, which could account for only part of the assimilation by sugar beet leaves, did not appear to be utilized by soybean leaves. An alternate pathway for the reduction of carbon dioxide to the carbohydrate level is postulated to account for the assimilation patterns observed in the two species.
A NOTE ON HYBRIDIZATION BETWEEN QUERCUS MACROCARPA MICHX. AND QUERCUS BICOLOR WILLD. IN WISCONSIN
Authors: Bray J. R.
Published: August 2008

Collections of acorns were made in southern Wisconsin from trees identified on leaf and bark characters as Quercus macrocarpa Michx., Q. bicolor Willd., and their hybrid ×Q. schuettei Trel. Measurements were made of peduncle length, cup fringe length, acorn width, and acorn length. Cup fringe length and acorn length and width decreased and peduncle length increased from Q. macrocarpa through the hybrid to Q. bicolor. The hybrid was clearly separated from Q. macrocarpa on peduncle length. A possible introgression between ×Q. schuettei and Q. bicolor was noted.
AQUATIC HYPHOMYCETES FROM CANADA
Authors: Ingold C. T.
Published: August 2008

Fifteen species of aquatic Hyphomycetes are described from Canada. Further, some spore types are illustrated which do not seem to belong to known species.
"STEREUM PINI" IN NORTH AMERICA
Authors: Weresub Luella K. , Gibson Shelagh
Published: August 2008

Interfertility tests between American "Stereum pini", European "Stereum pint", and American Peniophora duplex have shown that a closer relationship exists between the latter two taxa than between them and the first-named taxon. This genetic relationship is supported by their morphology in non-fruiting culture though not by the morphology of their natural fructifications. It is concluded that the three taxa are best treated, at present, as Peniophora pini aggregate, composed of P. pini (Schleich. ex Fr.) Boidin subsp. pini (of Europe), P. pini subsp. duplex (Burt) stat. nov., and P. pseudo-pini nom. nov. (both of North America).
INCORPORATION OF P32 INTO RIBONUCLEIC ACID OF RUSTED WHEAT LEAVES
Authors: Rohringer R. , Heitefuss R.
Published: August 2008

P32-labelled orthophosphate was fed to rusted and non-rusted wheat leaves. The ribonucleic acid (RNA) isolated from this material was purified and its specific activity determined. The specific activity of RNA from susceptible reacting tissue had increased 60–208% [Formula: see text] days after inoculation, but [Formula: see text] days after inoculation it was not markedly different from RNA preparations of uninoculated leaf material, indicating an increase and eventual decline in RNA synthesis of the host–parasite complex. In the resistant reaction incorporation of P32 into the RNA was unaltered by infection. The possible metabolic significance of these observations is discussed.
NATURAL SELECTION AMONG HYBRIDS BETWEEN CARDUUS ACANTHOIDES AND C. NUTANS IN ONTARIO
Authors: Mulligan Gerald A. , Moore Raymond J.
Published: August 2008

Natural hybridization is occurring between two introduced thistles, Carduus acanthoides L. and C. nutans L., in the southern half of Grey County, Ontario. The morphological variation of plants in 37 fields, including a field near Priceville previously studied in 1952, was evaluated by means of a hybrid index in 1957. Carduus nutans was first established in the hybrid area and C. acanthoides was introduced later, probably from the region northwest of Owen Sound, into waste land near Flesherton, where hybridization first occurred. Many large hybrid populations were found in the southern portion of Grey County and most of these hybrids were very similar to C. acanthoides in morphology. It was concluded that there is a numerical supremacy of acanthoides-type hybrid segregates in the hybrid area, and that such hybrids are better adapted for survival under local conditions than C. nutans and will probably supplant the latter species.
GROUPING OF ISOLATES OF A LOW-TEMPERATURE BASIDIOMYCETE ON THE BASIS OF CULTURAL BEHAVIOR AND PATHOGENICITY
Authors: Ward E. W. B. , Lebeau J. B. , Cormack M. W.
Published: August 2008

Isolates of an unidentified low-temperature basidiomycete, associated with snow mold in Western Canada, were divided into three types, A, B, and C, on the basis of their general cultural appearance. Support for this classification was obtained when representative isolates of each type were examined to determine: the effect of temperature and pH on growth; tolerance of antibiotics and HCN; ability to liberate HCN in culture and in the host plant; pathogenicity.Type A isolates grew slowly under most conditions and were least tolerant of the extremes of temperature and pH employed, moderately inhibited by antibiotics, and strongly inhibited by HCN. They produced HCN in large quantities in host plants and none in culture. They were moderately pathogenic on grass and highly pathogenic on alfalfa. Type B isolates grew somewhat more rapidly than type A, especially at the upper and lower temperatures, and grew over a wider pH range. These isolates were more tolerant of antibiotics and HCN. They produced smaller quantities of HCN than type A in infected alfalfa plants but released large amounts in culture. They were less pathogenic than type A on alfalfa but similarly pathogenic on grass. Type C isolates were fast-growing forms which were strongly inhibited by antibiotics and HCN. They did not liberate HCN under any conditions and were not pathogenic.
THE EFFECT OF 3-AMINO-1,2,4-TRIAZOLE ON THE UPTAKE, RETENTION, DISTRIBUTION, AND UTILIZATION OF LABELLED PHOSPHORUS BY YOUNG BARLEY PLANTS
Authors: Wort D. J. , Loughman B. C.
Published: August 2008

Seedlings of barley were grown to the 3-leaf stage in phosphate-free nutrient solution and AT was added at such times that the roots were in contact with 100 p.p.m. of the compound for 96, 48, 24, 4, 1, or 0 hours immediately prior to transfer to labelled phosphate solution for 1 hour. The plants were then returned to phosphate-free nutrient solution and harvested 1, 2, 4, 24, 48, and 96 hours after the start of the contact with radioactive solution. In an experiment designed to determine the effect on utilization of phosphate the immersion in AT was of 48 hours' duration.Exposure to AT diminished uptake of P32 but also decreased the subsequent loss to the environment. The activity in both acid-soluble and acid-insoluble fractions of the root was reduced by treatment but exposure to AT for up to 48 hours increased the amount of P32 translocated to the shoot. The proportion of the absorbed phosphate found in the shoots of treated plants was higher than in the controls.For 2 to 4 hours the incorporation of P32 into both acid-insoluble (nucleic acids, phospholipids, phosphoprotein) and acid-soluble (nucleotides, sugar phosphates, inorganic phosphate) fractions showed little deviation from normal, but by the end of 24 hours AT treatment caused a decrease in the acid-insoluble fraction of both roots and shoots. The pattern of esterification was changed but little.Apparently the effect of AT on phosphate metabolism is not concerned with the reactions of oxidative phosphorylation or of glycolysis, but is confined to the processes involved in the incorporation of phosphate during the synthesis of nucleic acids.
LYCOPERDON IN EASTERN CANADA WITH SPECIAL REFERENCE TO THE OTTAWA DISTRICT
Authors: Bowerman Constance A.
Published: August 2008

Twenty-one species of the genus Lycoperdon have been described, one of which is a new species, L. flavotinctum. Eighteen species have been found in the Ottawa area while the remaining three could be expected to occur.
GROWTH AND MORPHOGENESIS IN THE CANADIAN FOREST SPECIES: V. FURTHER STUDIES OF WOOD 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 in trunk and branches of four red pine trees of different situations is extended to include internode length, circumference, annual wood volume increment, and cambial area. The effects of position of a branch on the tree and of suppression and release are examined in reference to these growth indexes.Increase in circumference responds in much the same way as radial growth, and branch position is important. The greatest annual increase in girth of any branch internode occurs when it is near the periphery and near the top of the tree.Terminal growth of branches is less affected than radial or tangential growth by branch position if the tree is in the open but is suppressed by surrounding trees. Upon release of a tree only those axes whose local environment was actually improved showed an increase in apical growth.The interpretation of annual wood volume increment is complicated by the fact that it is determined not only by internal and external conditions during the current growing season, but also by past growth, both apical and cambial. It is subject to the effects of suppression and of branch position, chiefly through the influence of these factors on the cambial growth component.
A KARYOTYPE STUDY OF ANEMONE DRUMMONDII AND ITS HYBRID WITH A. MULTIFIDA
Authors: Heimburger Margaret
Published: August 2008

A collection of Anemone drummondii S. Wats. from Jasper National Park, Alberta, has been found to be hexaploid, 2n = 48. Chromosome pairs belonging to each of the groups, I–VIII, can be identified with few exceptions, on the basis of relative length and centromere position. Since several well-characterized pairs are represented only once, the allopolyploid nature of this species is evident. Metaphase plates from hybrids with A. multifida Poir. var. hudsoniana DC. allow a direct comparison between the parental karyotypes. Similarity of one chromosome set from each parent suggests that these sets were contributed by the same or by closely related ancestral species.
ASSOCIATION BETWEEN ASCORBIC ACID CONCENTRATION AND COLD HARDENING IN YOUNG WINTER WHEAT SEEDLINGS
Authors: Andrews J. E. , Roberts D. W. A.
Published: August 2008

The ascorbic acid content of winter wheat varieties, germinated in the dark at various temperatures on the surface of moist vermiculite, was much higher at a hardening temperature of 1.5 °C than at higher temperatures of 5°, 10°, or 20 °C. There were no differences between the ascorbic acid contents of wheat grown at the three higher temperatures. Ascorbic acid content was dependent on the stage of development at all temperatures. At 1.5 °C, the ascorbic acid content increased during the first 6 weeks of growth (shoots about 15 mm) and then decreased rapidly. This variation in ascorbic acid content was closely associated with the increase and decrease in cold hardiness of wheat grown under similar conditions.Ascorbic acid content was highest in shoots, intermediate in roots, and lowest in the endosperm of wheat grown for 6 weeks at 1.5 °C.At hardening temperatures (1.5° and 3 °C) the more cold hardy winter wheat varieties had higher contents of ascorbic acid. At higher temperatures the differences between varieties were small. The ranking of varieties by ascorbic acid content could be influenced by relative stages of growth.Artificial cold hardiness was imparted to winter wheat seedlings by feeding them aqueous ascorbic acid solutions of adequate concentration. The ascorbic acid content of leaves required for artificial hardening appeared to be similar to that accumulated in sprouts hardened fully by growth at low temperature.
THE INTERACTION OF THIRAM AND SPORES OF GLOMERELLA CINGULATA SPAULD. & SCHRENK.
Authors: Richardson Lloyd T. , Thorn G. D.
Published: August 2008

The reduction of thiram by microorganisms, observed qualitatively by previous workers, is shown to occur in the external solution with spores of Glomerella cingulata. Quantitative examination of the process indicates that in the absence of copper ions there is no measurable uptake of either thiram or its reduced form, dimethyldithiocarbamic acid, by the spores. In the presence of copper ions, dimethyldithiocarbamate is lost from solution and fungitoxicity is increased. Evidence of uptake of copper dimethyldithiocarbamate by the spores is not conclusive, however, due to the formation of a precipitate. The exudate from the spores in time solubilizes this precipitate with a concomitant reversal of fungitoxicity. A new technique, wherein a paper strip treated with a metal salt is laid at right angles to one treated with thiram or a dithiocarbamate on an agar sheet seeded with G. cingulata spores, has supplied corroboration of the hypothesis involving the two copper dimethyldithiocarbamate complexes in the bimodal dosage response of microorganisms to dithiocarbamate toxicants.
THE OCCURRENCE OF TETRASPORANGIA AND CARPOSPOROPHYTES ON THE SAME THALLUS IN EUTHORA CRISTATA (L. ex TURN.) J. AG.
Authors: Dixon Peter S.
Published: August 2008

The occurrence of tetrasporangia and carposporophytes on the same thallus is reported in Euthora cristata (L. ex Turn.) J. Ag. collected in the Maritime Provinces, the first report of such a phenomenon in this genus.
VARIATION IN THE BANANA-WILT PATHOGEN, FUSARIUM OXYSPORUM f. CUBENSE
Authors: Page O. T.
Published: August 2008

The validity of many of the strains of Fusarium oxysporum f. cubense which have been reported rests primarily upon the cultural criteria used in their differentiation. An examination of certain of these cultural features, such as the presence or absence of odor, pigmentation, 'interaction', and colony morphology did not permit conclusive identification of strains. 'Finger printing' by means of chromatographic assay of exogenous amino acids, measurements of growth, and the production of fusaric acid by single-spore cultures of strains of the banana-wilt fungus confirmed initial observations that so-called clones, cultivars, varieties, and groups overlapped and were inseparable.Methods for the isolation of single microconidia from the lumen of individual host cells, a microculture technique which employed 0.5 ml of liquid medium, and the determination of 27 ninhydrin-reactive substances in culture filtrate are described.
STUDIES ON RUBUS VIRUS DISEASES IN BRITISH COLUMBIA: VII. RASPBERRY VEIN CHLOROSIS
Authors: Stace-Smith Richard
Published: August 2008

A virus disease occurring in the Lloyd George variety of red raspberry (Rubus idaeus L.) in British Columbia has been identified as raspberry vein chlorosis, a disease previously reported from Scotland. The virus was transmitted to the Lloyd George and Washington varieties of red raspberry, loganberry (R. loganobaccus Bailey), and the Alpine strawberry (Fragaria vesca L.) by the aphid Aphis idaei V.d.G. In each of these hosts, the characteristic symptom was a net-like chlorosis of the tissue bordering the smaller veins of the leaf. The large raspberry aphid, Amphorophora rubi (Kalt.), was not a vector. Experiments using A. idaei showed that most individuals require more than 1 day on the virus source to become viruliferous. The length of time that aphids remained viruliferous depended upon the conditions of the test; viruliferous aphids feeding upon healthy raspberry plants lost the ability to transmit the virus within a day, while those feeding upon strawberry, or held in a Petri dish without food, retained the virus longer than 1 day.
A NOTE ON THE QUANTITATIVE DETERMINATION OF C14-RADIOACTIVITY ON PAPER CHROMATOGRAMS
Authors: Bidwell R. G. S.
Published: August 2008

The accuracy of measuring radioactivity on paper chromatograms by direct counting with a Geiger counter has been determined. It has been shown that satisfactory accuracy can only be obtained when the chromatograms are dried in still air. When chromatograms are allowed to dry in a draft, substances in the spots tend to concentrate erratically at the surfaces of the paper causing errors of up to 25% in counting.
VARIATIONS IN LEAF NUMBER IN HIPPURIS. A STUDY OF WHORLED PHYLLOTAXIS
Authors: McCully Margaret E. , Dale Hugh M.
Published: August 2008

The number of leaves per verticil in the material examined varied from 2 to 16. The variation in leaf number from verticil to verticil cannot be correlated to the splitting of primordia, junctional forces, binding whorls, acropetally developing forces from the stele, positions of leaf traces, nor to a constant angle between leaf insertions at every node. In tracing the development of leaves it is clear that nodes bearing leaves are produced in partially differentiated internodal tissue, as the apical thimble enlarges and grows. The leaves are not initiated at a constant distance from the tip and the larger the circumference of the leaf insertion disc, the larger is the number of leaves. The centers of the leaf primordia are circa 50 microns apart in each verticil. The initiation of leaves is traced in both aerial and aquatic apices using material from a single clone and also from a variety of sources. Aerial apices are usually smaller than aquatic ones and are of a different shape. However, the primordia are apparently the same until they are 50 microns long. Seven cells in the second layer divide periclinally to initiate each primordium. The study suggests that each of these groups of seven cells originates from anticlinal divisions of a single cell. The several cells separating the groups also originate from a single cell.
DEMONSTRATION OF PHOTOPERIODIC ECOTYPES IN LIRIODENDRON AND QUERCUS
Authors: Vaartaja O.
Published: August 2008

Seedlings of Liriodendron tulipifera responded very sensitively to daylength treatments in growth chambers. A certain daylength (6-hour night) inhibited northern but not southern seedlings. The same was true with seedlings of Quercus macrocarpa but the inhibition occurred under very short days (12-hour night) and the responses were smaller. In this species the onset of dormancy was controlled more strongly by the endogenous growth rhythm. The different photoperiodic responses appear to be an adaptation mechanism in these as well as in other species studied earlier. The responses could conceivably function for reliable timing in the alternation of growing and dormant stages.
NUCLEAR PHENOMENA IN THE BASIDIUM OF CERATOBASIDIUM PRATICOLUM (KOTILA) OLIVE
Authors: Saksena H. K.
Published: August 2008

The nuclear phenomena in the basidium of Ceratobasidium praticolum (Pellicularia praticola), studied by the Giemsa technique, are described and illustrated with photographs. The cells of the vegetative hyphae are multinucleate and those of the hymenia binucleate. Before fusion the two nuclei in the young basidium become closely adjacent, and their chromosomes are differentiated as elongated threads in two distinct groups. After the association of the karyolymph of the two nuclei, the chromosomes come into contact and pair. The diploid nucleus then undergoes meiosis. The haploid chromosome number is about six, with six bivalents present at the first meiotic (disjunctional) division. Apparent chromatid bridges were observed at anaphase I. The second meiotic division is equational. The spindle axis during both these divisions may be longitudinal, transverse, or oblique. The mature basidium has four nuclei which migrate through sterigmata into the basidiospores. Most of the basidiospores are uninucleate when young, but become binucleate at maturity. The basidiospore germinates by repetition or directly by a germ tube. In either case coenocytic growth is produced which, upon further development, is divided into multinucleate hyphal cells by the formation of cross septa.
NUCLEAR STRUCTURE AND DIVISION IN THE MYCELIUM AND BASIDIOSPORES OF CERATOBASIDIUM PRATICOLUM
Authors: Saksena H. K.
Published: August 2008

Nuclear structure and division in the mycelium and basidiospores of Ceratobasidium praticolum (Pellicularia praticola), studied in living and in differently stained preparations, are described and illustrated with photographs. The cells of the mycelium are multinucleate. Nuclear migration occurs from one cell to another through the septal pores. The nuclei consist of a Feulgen-negative nucleolus surrounded by granular Feulgen-positive chromatin. In a nucleus preparing to divide, the nucleolus becomes progressively smaller and finally disappears. The chromatin then elongates, becoming bar-like, and later constricts at the mid-region. New nucleoli appear in the two attached portions of the constricted chromatin. At the end of the division the two portions pull apart to form two sister nuclei. Classic mitotic division as it occurs in higher organisms was not seen. Chromosomal filaments were not discerned in the nuclei of the basidiospores or the mycelium. Chromosomal filaments in reticulate arrangement were observed in the nuclei of the hymenial cells and in the cells of the short, side branches on which the hymenium develops.
CYTOLOGICAL STUDIES IN BROMUS SPECIES, SECTION BROMOPSIS
Authors: Hanna M. R.
Published: August 2008

Chromosome numbers and meiotic behavior were determined in clones of Bromus inermis, Bromus pumpellianus, and the Bromus erectus complex. Clones of B. inermis were octoploid (2n = 56) or near-octoploid, one aneuploid having 2n = 54 chromosomes. B. pumpellianus clones were octoploid, with one bearing a B chromosome. B. erectus-type clones had 56, 59, 65, or 70 chromosomes. Meioses varied widely among plants in extent of irregularity. Meiotic behavior was studied in detail and the sequential interrelationships of irregularities at meiotic stages analyzed. Significant or highly significant positive correlations were obtained for the B. pumpellianus clones between percentages of non-stainable pollen and frequencies of metaphase I univalents, anaphase II laggards, and quartet micronuclei. These relationships were non-significant for the B. inermis and B. erectus-type clones. A significant negative correlation was determined between percentage of non-stainable pollen and percentage of seed set following open pollination, but other relationships between meiotic irregularities or pollen stainability and seed-setting characteristics were non-significant. The wide range in chromosome number and meiotic behavior encountered in material commonly distributed on this continent as "B. erectus” may be due to interspecific hybridization in nurseries in which Bromus introductions are grown. Interspecific hybridization may be partially responsible also for aneuploidy and meiotic irregularity in B. inermis.
RIBONUCLEASE ACTIVITY IN RUSTED WHEAT LEAVES
Authors: Rohringer R. , Samborski D. J. , Person C. O.
Published: August 2008

Extracts from primary leaves of Lee wheat were prepared at various days following inoculation with races of leaf rust and tested for ribonuclease (RNase) activity. As early as 24 hours after inoculation there was a marked increase in the specific activity of the enzyme in extracts of rusted host tissues. A further increase in activity was observed during later stages of infection, with the susceptible and resistant reacting tissue differing only in the degree of their response. Extracts from noninoculated control leaves exhibited a constant RNase activity throughout the period of observation. The germination medium and extracts from germinating uredospores contained comparatively little RNase activity. No direct evidence was obtained either for the possible release of the enzyme from particulate cellular fractions of the host tissue as a result of infection or for the removal of an RNase inhibitor in the host tissue responding to infection.
STUDIES ON ASCOCHYTA IMPERFECTA PECK: PARASITIC STRAINS AMONG FIFTY ISOLATES FROM CANADIAN ALFALFA SEED
Authors: Mead H. W. , Cormack M. W.
Published: August 2008

Fifty isolates of Ascochyta imperfecta from alfalfa seed grown in Ontario, Manitoba, Saskatchewan, Alberta, and British Columbia produced varying degrees of infection on excised leaves of Medicago falcata, Medicago sativa (three strains), Melilotus alba, Melilotus officinalis, Trifolium pratense, Lotus corniculatus, Pisum sativum, and Vicia faba. F tests from analyses of variance of disease ratings showed that the differences in susceptibility between hosts and between strains of Medicago were highly significant. Among the 10 hosts and within the strains of Medicago, the interaction isolates × hosts was highly significant. Thus, specificity among the isolates was clearly demonstrated. This is interpreted to mean that parasitic strains existed among the 50 isolates.A. imperfecta was isolated from 50 to 70% of the seed samples from each province. The heaviest infestation was on seed from Manitoba, where the weather at harvest time was wet and where the crop overwintered in the field.
THE EFFECT OF NUTRITION ON SYNNEMATA FORMATION IN HIRSUTELLA GIGANTEA PETCH
Authors: Loughheed T. C.
Published: August 2008

The influence of nutrition on synnemata formation in Hirsutella gigantea has been studied. A number of carbon sources were satisfactory but a "crude glucose" preparation was the best. Only two nitrogen sources gave good yields of synnemata and both were rather complex mixtures. Two other compounds, phosphoglyceric acid and gibberellic acid, both known stimulants of other morphological processes, also increased synnemata production.An apparent light requirement of synnemata formation may also be satisfied by some compound(s) in "crude glucose", liver fraction L, and autolyzed yeast. Phosphoglyceric acid and gibberellic acid were more effective stimulants in the dark than in the light.Synnemata were formed earlier and were more plentiful if the medium was inoculated by flooding rather than with a loop.A medium which will support the growth of H. gigantea and the production of synnemata within 4 weeks has been formulated.It is concluded that the diversity of factors influencing synnemata formation indicates that the morphological differentiation is a multistep process which may be affected at several points.
THE BOTANY OF THE NORTHWESTERN QUEEN ELIZABETH ISLANDS
Authors: Savile D. B. O.
Published: August 2008

Ellef Ringnes Island has a confirmed flora of 49 vascular plants and five parasitic fungi. The adjacent islands have less diversity of habitat and probably have even poorer floras. There are no endemics and the plants are extremely depauperate. The summer climate at Isachsen is colder than at any other station in the Canadian arctic. Although there are no convincing indications that Ellef Ringnes I. was overrun by a Wisconsin continental ice sheet, it cannot have escaped being snow-covered. The light cover of snow and ice on the outer islands was quickly lost in the postglacial xerothermic, which enabled plants to spread along the periphery of the archipelago. The numerous plants that occur south-west and northeast of these islands but not in them indicate that postglacial cold periods, probably accompanied by at least partial snow cover of the outermost islands, have driven out many species. Nearctic refugia are discussed and it is indicated, by analysis of distribution patterns, that no refugia occurred in the Canadian arctic archipelago. The region has been colonized from the Peary Land refuge, the Yukon–Alaska refugia, and from south of the retreating ice sheets.
THE USE OF AMMONIUM SOURCE OF NITROGEN IN THE METABOLISM OF ASPERGILLUS NIDULANS EIDAM
Authors: Naguib Kaiser , Saddik Kamel
Published: August 2008

Aspergillus nidulans was grown as surface cultures on three ammonium salts, namely: ammonium chloride, ammonium carbonate, and ammonium nitrate in a basal medium favorable for fat formation. It was also grown on sodium nitrate for comparison. Growth, uptake of sugar and nitrogen, fat and protein syntheses, and pH change in the culture media were all followed over an incubation period of 20 days at 25° C.Growth on ammonium chloride was suppressed after a short period, when the pH of the medium dropped to a very low value. Mycelial felts had high protein contents but insignificant amounts of fat. In ammonium carbonate cultures, fungal growth continued yielding heavy mycelial felts with high fat content. But nitrogen utilization ceased while an ample supply was still present in the culture medium leading to low protein content in the mycelial felts. This could not be attributed to any drastic change in the pH of the culture medium; the pH changed only within reasonable limits.Growth was best on ammonium nitrate. Mycelial felts contained high protein and high fat. The change in pH of the medium, during the early period of incubation, indicated preferential absorption of ammonium to nitrate ions. Growth on sodium nitrate started by a lag period, but soon became active and gave rise to a heavy mycelium.The present findings also showed that nitrate nitrogen was more conducive to protein synthesis by Aspergillus nidulans than was ammonium nitrogen. Fat formation, on the other hand, was lower on sodium nitrate than on ammonium carbonate or ammonium nitrate.
SEXUALITY AND INTERFERTILITY STUDIES IN POLYPORUS ABIETINUS, P. PARGAMENUS, AND P. VERSATILIS
Authors: Bakshi B. K. , Choudhury T. G.
Published: August 2008

The closely related fungi Polyporus abietinus, P. pargamenus, and P. versatilis, which were heterothallic and tetrapolar, were proved to be distinct species by interfertility tests. P. versatilis occurring on four species of timber showed multiple allelomorph heterothallism for both sex factors.