摘要:

Stachybotrys aurantiais described as a new species of hyphomycete isolated from soil; it differs from other described species of the genus in phialide and phialospore morphology and is also distinctive in having pale orange or salmon-colored phialospores. Cultural studies show that it has a rapid growth rate and, on a minimal synthetic medium, requires a biotin supplement for normal growth.

ISSN:0008-4026    

DOI:10.1139/b62-024

出版商:NRC Research Press    

年代:1962

数据来源: NRC

摘要:

Pycnidia ofAscochyta imperfectaPeck are mature on alfalfa in March and April in Saskatchewan. Development, exudation, and spread of pycniospores are dependent upon moisture. Black stem, caused by this fungus, usually fails to appear in dry years until late in the season. This was very noticeable in the very dry season of 1961. Pycniospores remained viable in dry stem material up to 50 months. Pycnidia developed on synthetic media and on sweet clover stems over a range of 20° to 80° F; the optimum was 65° to 75° F. Light did not affect pycnidial formation, but relative humidity was a controlling factor. Development was profuse at 80 to 100%, but did not occur at a constant 100%. Various isolates ofAscochyta imperfectareacted differentially to the kind and concentration of sugars, balance of sugar and nitrogen, and, in the early stages, kind of amino acids in synthetic media. The kind of nitrogen supplied was not limiting, but addition of nitrogen to the medium favored pycnidial development more than addition of sugar. The relative ability of isolates ofAscochyta imperfectato utilize nutrients in their changing forms for production of spores is considered important in the survival of parasitic strains.

ISSN:0008-4026    

DOI:10.1139/b62-025

出版商:NRC Research Press    

年代:1962

数据来源: NRC

摘要:

Young jack pine (Pinus banksianaLamb.) were defoliated manually to measure the effects of defoliation on growth of this species, and to determine the relative efficiency of foliage of different ages with respect to growth. The removal of 2-year-old or 3-year-old foliage had no appreciable effect on tree growth, but their joint removal reduced height growth. Height growth was also reduced by the removal of 1-year-old foliage. Current foliage was found essential for the maintenance of normal height, diameter, and shoot growth; in addition, its removal induced high bud mortality, the production of profuse adventitious growth, and a reduction in the rate of shoot elongation. Trees deprived of all but current foliage showed marked reductions in height, diameter, and shoot growth. Complete defoliation resulted in tree death shortly thereafter. Growth reductions resulting from some of the treatments approximated that following defoliation by the Swaine jack-pine sawfly (Neodiprion swaineiMidd.). Also, the present results are compared with those obtained by several other workers in this field.

ISSN:0008-4026    

DOI:10.1139/b62-026

出版商:NRC Research Press    

年代:1962

数据来源: NRC

摘要:

Chromosome numbers of 40 taxa of nine genera of the Cynareae together with discussions of pertinent taxonomic problems are presented. Chromosome counts for 26 taxa are presented for the first time; the chief of these are:Carduus cernuus, n = 11;C. pycnocephalusandC. tenuiflorus, 2n = 54;Cirsium arachnoideum, C. obvallatum, C. pendulum, C. tricholoma, 2n = 34;Echinops(six species), 2n = 30;Notobasis syriaca, 2n = 34;Onopordum(two species), 2n = 34;Saussurea densa, 2n = 26;Silybum eburneum, n = 17. The morphology of the chromosome complements is discussed in relation to the interrelationships and phylogeny of these genera. Cytological evidence supports the retention ofNotobasisandChamaepeuceas distinct fromCirsium.

ISSN:0008-4026    

DOI:10.1139/b62-027

出版商:NRC Research Press    

年代:1962

数据来源: NRC

摘要:

The taxonomy ofLinaria dalmatica(L.) Mill. is discussed and a lectotype is selected, viz plant-number XII.10,Linaria latifolia Dalmatica, magno floreBauh., in the Joachim Burser herbarium, which is preserved in Uppsala. A comprehensive description of the species is given. Two varieties are included: var.dalmatica, native from Yugoslavia to Iran, and var.macedonica(Griseb.) Vandas, indigenous to the mountains of southern Yugoslavia. Photographs of the type specimens of each are presented.L. grandifloraDesf. is shown to be a synonym of var.dalmatica, and Vandas is the correct authority for var.macedonica. Var.macedonicaprobably has never been cultivated but var.dalmaticawas under cultivation at least as early as 1594 in Europe. It is now cultivated in Asia and North America as well as in Europe. Although probably introduced into North America by 1894, the earliest voucher specimen is dated 1920. Presently growing in 15 states in the U.S.A. and six provinces in Canada, var.dalmaticahas escaped from cultivation and has spread as a weed in very diverse habitats, especially in coarse-textured soils west of the 100th meridian.

ISSN:0008-4026    

DOI:10.1139/b62-028

出版商:NRC Research Press    

年代:1962

数据来源: NRC

摘要:

Mycelium ofMelampsorawas grown on flax cotyledons in tissue cultures. Mycelium and uredospores were incubated withDL-tryptophane-2-C14and uredospores were incubated withL-tryptophane. Acid and neutral ether-soluble and aqueous fractions of the plant material and incubation medium were chromatographed and sprayed with chromogenic agents or radioautographed. Radioactive indoleacetic acid was produced in small amounts by both mycelium and spores (yield = 0.016% in 8 hours). The auxin was identified on the basis of itsRfvalues in two solvent systems, its reactions with Ehrlich and Salkowski reagents, and its ability to promote extension growth ofAvenacoleoptiles. Evidence for the formation of indoleacetaldehyde was also obtained. Several other radioactive and Ehrlich-positive products of tryptophane metabolism were detected but not identified. One of these could have been indolepyruvic acid. Tryptamine and indoleacetonitrile were not found. The results suggest that, inMelampsora, the synthesis of indoleacetic acid from tryptophane proceeds through indolepyruvic acid and indoleacetaldehyde.

ISSN:0008-4026    

DOI:10.1139/b62-029

出版商:NRC Research Press    

年代:1962

数据来源: NRC

摘要:

Detached tobacco leaves were placed singly into a photosynthesis chamber and illuminated in the presence of C14O2with white, red, or blue light. Two kinds of experiments were carried out. In the first, the energy of the three kinds of incident light was adjusted so that the rate of CO2uptake was the same. In the second, the energy of the three kinds of incident light was the same and the time adjusted so that an equal amount of CO2was taken up by each leaf. At the end of photosynthesis the distribution of C14was determined in the ethanol-soluble and-insoluble fractions and among the various compounds of the ethanol-soluble fraction that were separated by paper chromatography.No effect of wavelength of light was observed on the distribution of absorbed carbon dioxide between the ethanol-soluble and -insoluble fractions. Neither was there any evidence that red light stimulated synthesis of soluble sugars. Red light, compared with white, increased incorporation of carbon dioxide into glycine, but had no effect on serine. Blue brought about a considerable decrease in glycine and some decrease in serine.A tentative explanation is given of a mechanism by means of which the wavelength of light may affect the distribution of absorbed carbon dioxide among the various photosynthetic products.

ISSN:0008-4026    

DOI:10.1139/b62-030

出版商:NRC Research Press    

年代:1962

数据来源: NRC

摘要:

Microscopic studies were conducted on weather fleck, a non-parasitic plant disorder of flue-cured tobacco in Ontario. Within a few hours of the initial appearance of the flecks, damage was restricted to the palisade parenchyma cells; after about one day some of the spongy parenchyma cells also were affected. There was no apparent difference between flecked and healthy tissue with respect to thickness or structure of the cell wall. In affected tissue, the nuclei of the palisade cells were shrunken to spherical, ellipsoid, or irregularly ellipsoid shapes with average measurements of 6.0 × 5.1 μ; in adjacent undamaged cells, they averaged 9.1 × 7.3 μ. The nuclei of damaged cells stained more heavily than nuclei of normal cells and their structural details were lost. Chloroplasts of flecked and healthy palisade cells were almost of an equivalent size, the average lengths being 4.3 μ and 4.4 μ, respectively. However, chloroplasts in flecked cells had often been disrupted. Evidence is presented to support the hypothesis that the unknown agent or agents causing weather fleck first affect the cytoplasm and nucleus, then the chloroplasts.

ISSN:0008-4026    

DOI:10.1139/b62-031

出版商:NRC Research Press    

年代:1962

数据来源: NRC

摘要:

The perfect state ofChondropodium pseudotsugaeWhite is shown to be a new species ofDurandiella, for which the nameD. pseudotsugaeis proposed. Maximum growth in culture is obtained on corn meal agar at 15 °C. Apothecia are produced in the spring; the ascospores are forcibly discharged; pycnidia persist throughout the summer and discharge spores only when moistened. The host response of Douglas fir is the production of a "button" of persistent secondary periderm beneath the infected area.

ISSN:0008-4026    

DOI:10.1139/b62-032

出版商:NRC Research Press    

年代:1962

数据来源: NRC

摘要:

Comparisons of morphological mutant strains ofNeurospora crassawith the wild type and with each other reveal differences in: (a) the general form of the colonies, resulting from different relative growth rates of the aerial submerged and surface mycelia; (b) the frequency of hyphal branching; (c) the abundance of conidia; (d) the compactness of the mycelia; and (e) various characteristics of the hyphae. The typical variant properties of each mutant strain depend upon the activity of some single mutant gene. The linkage position of six of the mutant genes is reported.

ISSN:0008-4026    

DOI:10.1139/b62-033

出版商:NRC Research Press    

年代:1962

数据来源: NRC