摘要:

The carbohydrates of sugar beet leaf were fractionated by successive extractions in ethanol, water, and three concentrations of potassium hydroxide. Quantitative hydrolysis of the polysaccharides from the water- and alkali-soluble fractions gave galactose, glucose, arabinose, xylose, ribose, and rhamnose in varying proportions. When these fractions from leaves which had photosynthetically assimilated C14O2for 10 to 120 seconds were analyzed, all fractions, including the alkali-insoluble cellulose, were labelled after only 10 seconds. The proportion of C14in the alkali-soluble fraction was high relative to that in cellulose after 10 seconds, but similar in both fractions after longer periods. All of the radioactivity in the carbohydrates was in glucose (apart from the fructose of sucrose). When photosynthesis in C14O2was followed by photosynthetic periods in normal air, the polysaccharide fractions all continued to receive C14-labelled glucose for about 5 minutes. No significant transfer of radioactivity from one fraction to another was detected during an additional 40 minutes. The data indicate that the formation of leaf polysaccharides is closely linked to early products of the photosynthetic assimilation of carbon dioxide, and that the different polysaccharides are formed concurrently with little interconversion.

ISSN:0008-4026    

DOI:10.1139/b62-001

出版商:NRC Research Press    

年代:1962

数据来源: NRC

摘要:

Growth of the fungusEchinodontium linctorium, cause of an important trunk rot in true firs, was studied at various fixed temperatures in vitro. A polynomial approximation of the three-dimensional growth surface over temperature and time was developed with the aid of statistical techniques and computer facilities. The growth of isolates from northern and central Sierra Nevada forest regions of California was compared in this manner. The optimum temperature of the northern isolates was found to vary with the period of observation. For these isolates, the optimum temperature for rate of growth decreased with time, approaching a constant value. The optimum temperature of the central Sierra Nevada isolates was not found to vary with time. At near-optimum temperatures, the estimated growth rate of isolates from northern California was 75% greater at 20 days than that of the central Sierra Nevada isolates. The estimated optimum temperatures of the isolates from the two regions differed by only 1.2 °C at 20 days. Deviations of 1.2 °C from the optimum produced only slight differences in the estimated growth rate of either group of isolates. Use of the constant "terminal optimum temperature" is suggested for describing the growth response of fungi. Unlike the commonly reported "optimum temperature", the value of the terminal optimum temperature does not depend upon the period of observation.

ISSN:0008-4026    

DOI:10.1139/b62-002

出版商:NRC Research Press    

年代:1962

数据来源: NRC

摘要:

Small amounts of copper ions induce the release from spores ofGlomerella cingulataSpauld. & Schrenk. of increased amounts of amino acids, predominantly glutamic acid, α-alanine, γ-aminobutyric acid, aspartic acid, glycine, leucine(s), and serine. Sodium dimethyldithiocarbamate, and copper in the form of the dimethyldithiocarbamate complex, do not show this effect. Added protein, such as egg albumin or cellulase, or the extracellular protein of spores suspended in water, forms a soluble ternary complex with dithiocarbamate and copper ions. This results in little or no loss of dithiocarbamate from solution and in reduced toxicity in the first mode of the dosage–response curve.

ISSN:0008-4026    

DOI:10.1139/b62-003

出版商:NRC Research Press    

年代:1962

数据来源: NRC

摘要:

A total of 83 taxa of Musci are enumerated from the prairies of Alberta, Saskatchewan, and Manitoba. These are composed of 36 soil-dwelling species, 21 that occur on rotting vegetation, 8 aquatics, 6 rupestral, and 3 corticolous. A large number of new provincial records are reported as well as the speciesMnium arizonicum, new to Canada. None of the species are endemic to the prairies and most attain greater abundance in neighboring wooded regions. The ecology of the region and early collections are discussed.

ISSN:0008-4026    

DOI:10.1139/b62-004

出版商:NRC Research Press    

年代:1962

数据来源: NRC

摘要:

Extensive sampling of naturally infected field and greenhouse tomatoes has revealed the presence of a specialized form of the tobacco mosaic virus. This tomato form, readily differentiated from that commonly occurring in tobacco, has been found in widely separated geographic areas within Canada, and is the dominant, if not the only, form in tomato even in regions where tobacco and tomatoes are grown as contiguous crops. This specialization to tomato of a virus form distinct from that in tobacco does not support the view commonly held that smoking tobacco is the main source of inoculum for the mosaic disease in commercial tomatoes.

ISSN:0008-4026    

DOI:10.1139/b62-005

出版商:NRC Research Press    

年代:1962

数据来源: NRC

摘要:

IAA, IAN, accelerator α, and an ether-insoluble growth substance (designated as 'A') were found in alcohol extracts of healthy inflorescences ofBrassica napusL. and in smaller amounts in the malformed, parasitized inflorescences produced by plants infected withAlbugo Candida(Pers. ex Chev.) Kuntze. The total activity of diseased extracts (≡ 915 μg IAA/kg fresh weight) was only 61% of that of healthy ones. IAN accounted for approximately 86% of the total activity in both extracts.Brassicais thus a good source of IAN. Both IAA and IAN were identified by their chromogenic reactions, ultraviolet spectra, andRfvalues in two solvent systems. Alkaline hydrolysis of 'A' produced an ether-soluble, Ehrlich-positive spot with the sameRfvalue as IAA. The results are discussed briefly.

ISSN:0008-4026    

DOI:10.1139/b62-006

出版商:NRC Research Press    

年代:1962

数据来源: NRC

摘要:

It has been shown that saprophytes were prevalent at the nodes, lenticels, and other irregularities on 1-, 2-, and 3-year-old bark ofPopulus trichocarpaTorrey and Gray andSalixsp. Antagonism tests demonstrated that the extracts of natural bark and two of the most common saprophytes inhibited the growth ofHypoxylon pruinatum(Klotzsch) Cke. However, the extracts of surface-sterilized bark were found to promote the cultural growth of the pathogen. No differences were observed in the behavior of the extracts obtained from dormant and actively growing bark tissues.The results of inoculation experiments demonstrated thatHypoxyloncanker did not develop when the saprophytes were present on watered greenwood cuttings of black Cottonwood and willow. However, the saprophytes were not effective in preventing infection and canker growth on cuttings with below-normal levels in bark turgor. Surface-sterilized cuttings proved susceptible to the disease at all levels of bark turgor.Possible relationships between the temperature and moisture requirements of the pathogen and representative bark antagonists, and the epidemiology of canker diseases caused by facultative parasites, are discussed.

ISSN:0008-4026    

DOI:10.1139/b62-007

出版商:NRC Research Press    

年代:1962

数据来源: NRC

摘要:

The haplophase of the life cycle ofStemonitis fuscais recorded and the method is described to study the haplophase activity of this myxomycete. In all stages of the haplophase the protoplast contains a vacuolar body which stains orangered with neutral red. The protoplast ofS. fuscadid not shed a membrane any time after emergence from the spore. Various sizes of myxamoebae were discovered and syngamy is described.

ISSN:0008-4026    

DOI:10.1139/b62-008

出版商:NRC Research Press    

年代:1962

数据来源: NRC

摘要:

A comparison betweenScolecobasidium constrictumAbbott andHeterosporium terrestreAtkinson shows them to be conspecific. The genusScolecobasidiumis preferred overHeterosporiumfor the disposition of this species.S. terreumAbbott is redescribed, andS. humicolaandS. variabiledescribed as new species.

ISSN:0008-4026    

DOI:10.1139/b62-009

出版商:NRC Research Press    

年代:1962

数据来源: NRC

摘要:

Hydrogen cyanide production by two pathogenic isolates of an unidentified basidiomycete was studied in shake culture in synthetic and natural media. Both isolates release HCN in infected host plants but one isolate (type A) failed to produce HCN in culture. Curves for growth and HCN production by the second isolate (type B) indicated that HCN is a product of autolysis and is not dependent on the provision of specific substrates in the medium.

ISSN:0008-4026    

DOI:10.1139/b62-010

出版商:NRC Research Press    

年代:1962

数据来源: NRC