Canadian Journal of Research
ISSN : 1923-4287
Published by: Canadian Science Publishing (10.1139)
Total articles ≅ 3,319
Latest articles in this journal
Canadian Journal of Research, Volume 28c, pp 613-622; https://doi.org/10.1139/cjr50c-037
The optimum temperature for fermentation of seven strains of the Ford type of Bacillus subtilis is close to 45 °C. At these higher temperatures 10% glucose or equivalent hydrolyzed molasses ferments completely in six days while 10% fructose takes only three days. The rate of fermentation is similar under aerobic or anaerobic conditions but agitation or shallow layers of media increase this rate. The yields of 2,3-butanediol, acetoin, glycerol, and lactic acid are high under anaerobic conditions but in the presence of oxygen the yield of glycerol and lactic acid is decreased. The organism demonstrates strong oxidative tendencies and can give a large yield of acetoin. Other factors affecting the fermentation are also assessed.
Canadian Journal of Research, Volume 28c, pp 637-644; https://doi.org/10.1139/cjr50c-039
Elongation of the vegetative branch of the blueberry ceases early in June owing to the death of both the apical meristem and the distal portion of the axis. Coincident with this is the development of a flowering branch primordium in the axil of the penultimate leaf. During July, the apical meristem of the flowering branch becomes inactive. It is either laterally displaced or it elongates as a minute unbranched columnar structure. Coincident with this inactivation, the proximal flower primordia develop florets in which all flower parts may be recognized, but the distal flower primordia, that is those adjacent to the inactivated apical meristem, are retarded in their development. The retarded distal flower primordia are developed in acropetal succession but the proximal flower primordia do not exhibit acropetal succession. All the stages are illustrated by line diagrams.
Canadian Journal of Research, Volume 28c, pp 690-698; https://doi.org/10.1139/cjr50c-042
Of 660 cultures of actinomycetes isolated on a nonselective basis from soils from five locations in Northern Canada, 404 strains, or 61.2%, showed antagonism against at least one of eight test organisms consisting of five bacteria and three plant pathogenic fungi. The degree of activity ranged from slight to strong, with the number of test organisms inhibited by any single culture varying from one to six. In all, 49 different antibiotic spectra were observed. Activity against one or more of the pathogenic fungi was shown by 138 cultures, 20.9% of the isolates. The percentage of active cultures was greater, and the degree of inhibition much more marked, against Helminthosporium sativum than against Fusarium culmorum or Fusarium lini. The percentage of active isolates varied with the location and with the depth of the soil. It is suggested that the high proportion of actinomycetes with antagonistic properties occurring in northern soils may be related to the lower degree of plant development in such regions.
Canadian Journal of Research, Volume 28c, pp 699-705; https://doi.org/10.1139/cjr50c-043
Turnip plants, heavily infested with the cabbage aphid, Brevicoryne brassicae (L.), and the green peach aphid, Myzus persicae (Sulz.), were inoculated with a virulent strain of Xanthomonas campestris (Pammel), the causal organism of black rot disease of turnips, and placed in special cages together with healthy turnip plants. Some aphids of both species were allowed to migrate naturally, and others were transferred mechanically from the diseased to the healthy plants, but no symptoms of black rot ever appeared in any of the latter plants. X. campestris was isolated from only 15% of the B. brassicae and from less than 1% of the M. persicae taken from the diseased plants. Aphids of both species were artificially contaminated externally with X. campestris by exposures to Petri plate and broth cultures of the pathogen. Internal contamination of other aphids of both species was accomplished by feeding them 0.2% aqueous dextrose solutions containing X. campestris. The pathogen was isolated from individuals m both groups of aphids thus contaminated, but none of the aphids in either group was able to infect caged, healthy turnip plants with black rot.
Canadian Journal of Research, Volume 28c, pp 706-715; https://doi.org/10.1139/cjr50c-044
The organic and inorganic requirements were determined for growth and pigment production by Pseudomonas nigrifaciens, an organism causing a reddish brown discoloration on the surface of mildly salted butter. Amino acids such as alanine, asparagine, proline, or glutamic acid were the best source of nitrogen for both growth and pigment production in a synthetic medium containing sodium chloride, inorganic salts, and glycerol; however, a carbohydrate was required only for pigment production in this amino acid medium. Na, K, Mg, S, P, and Cl or Br were also essential for both growth and pigmentation, larger amounts of these elements usually being required for synthesis of pigment than for growth. The dark brown-purple pigment produced was insoluble in all the common organic solvents hot or cold. With proline as a source of nitrogen a reddish-purple pigment developed which became deep purple then a deep brown purple. It is suggested that two pigments may be formed; one, a melanin-like dark brown substance originating possibly by polymerization of certain oxidation products of tyrosinase, the other, a dark purple condensation product of a secondary amine (such as proline) with the product (such as o-quinone) of a tyrosinase-catalyzed oxidation of phenolic substances produced by the organism.
Canadian Journal of Research, Volume 28c, pp 716-725; https://doi.org/10.1139/cjr50c-045
A series of nine delicate species, for the most part inconspicuous forms, which seem related to the more typical members of Bourdot and Galzin's section Athele of the genus Corticium are described and illustrated. The general features of the group are discussed as well as the possible interrelations of the species described.
Canadian Journal of Research, Volume 28c, pp 726-738; https://doi.org/10.1139/cjr50c-046
Thielaviopsis basicola (Berk. & Br.) Ferraris exists in nature in two distinct forms, termed the brown and the gray wild type, which are differentiated on potato dextrose agar. Pathogenicity on tobacco was found to be a function of the wild type culture used. All gray wild type cultures were less pathogenic than the brown. The brown wild type cultures consisted of at least two physiologic races. Race I is found in the "old belt" of Ontario, and in Quebec, Ohio, and Connecticut. Race II is present in the "new belt" of Ontario and in Kentucky. Race II and all gray wild type cultures are less pathogenic than Race I. All cultural mutants were less pathogenic than wild type cultures.
Canadian Journal of Research, Volume 28c, pp 739-744; https://doi.org/10.1139/cjr50c-047
The efficiency of a seed treating machine depends to a considerable extent on the uniformity with which the fungicide used for treatment is mixed with the seed. The uniformity of treatment may be ascertained by placing treated seeds, at 2-in. intervals, on large sheets of inoculated potato-sucrose agar. In the preparation of these sheets, melted, acidified agar is poured in a uniform layer over panes of glass and, when the agar has solidified, it is dusted heavily with spores of Penicillium purpurogenum Stoll. After the treated seed is placed on the agar, the culture is covered with a sheet of glass and incubated for two days at room temperature. The uniformity of treatment may then be determined from the variability in diameter of the zones of inhibition around the seeds. This technique may also be used for determining the comparative potency of different fungicides, and the rate at which they are lost from the seed.
Canadian Journal of Research, Volume 28c, pp 780-787; https://doi.org/10.1139/cjr50c-050
The fossilized remains of frond fragments, occurring as carbonaceous compressions, have been investigated by the transfer method and other palaeobotanical techniques. The structural details revealed, particularly those related to morphological features of the fructifications, facilitate discussion on the phylogeny of the plant. Spores and spore characters disclosed for the first time have also proved important from phylogenetic aspects. The plant is more closely related to the carboniferous representatives of Schizaeaceae than to the more recent members of this family.
Canadian Journal of Research, Volume 28b, pp 762-769; https://doi.org/10.1139/cjr50b-094
The copper salts of the basic amino acids (arginine, histidine, lysine, and ornithine) are formulated as complex salts. They contain a cation (with two positive charges) consisting of a copper atom and two amino acid molecules. The anion can be a simple inorganic group, such as Cl−, NO3−, SO4=. The complex copper amino acid cations form double complex compounds with anions HgI3− or HgI4=. The double complex salts of arginine, [Cu(C6H14O2N4)2][HgI4], and lysine, [Cu(C6H14O2N2)2][HgI3]2, are only slightly soluble in water and have characteristic crystal forms. They can be used for the quantitative determination of these amino acids. The copper salts of the natural amino acids are classified into four groups.