摘要:

A total of 26 species of coprophilous ascomycetes are recorded from the Hudson Bay Area in the following genera:Anixiopsis, one;Ascobolus, one;Coniochaeta, two;Delitschia, two;Gelasinospora, one;Gymnoascus, one;Melanospora, one;Phaeotrichum, one;Sordaria, five;Sphaeronaemella, one;Sporormia, nine;Trichodelitschia, one.Sordaria arcticaCain sp. nov., collected on the dung of wolf or fox at Churchill, Manitoba, and isolated in pure culture, differs fromS.humanain having smaller ascospores which are without a gelatinous sheath.Sporormia polymeraCain sp. nov., collected on the dung of caribou in Ungava, Quebec, has large ascospores with 14 to 15 cells.Anixiopsis stercorariacollected on fox dung in Quebec agrees morphologically with specimens collected in Ontario and obtained in pure culture as well as with the description of the Danish specimens given by Hansen. Specimens described by Stolk in 1955 from Peru are specifically different from the above and are redescribed asAnixiopsis peruvianaCain sp. nov.

ISSN:0008-4026    

DOI:10.1139/b57-022

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

Four of Atkinson's Alabama records are confirmed:Helminthosporium raveneliionSporobolus poiretii,H.leersiionLeersia virginica,H.flagelloideumonPanicumsp., andH.tuberosumonSecale cereale.H.tuberosumis an earlier synonym forH.secalis, the conidial state ofPyrenophora secalis. The collection ofH.inconspicuumonSecale cerealeisH tuberosum. The records ofH.turcicumonSorghum halepense,Cinna arundinacea, andElymussp. are based respectively onH.sorghicola,H.leersii. andH.sorokinianum, although the last two appeared to be saprophytic.

ISSN:0008-4026    

DOI:10.1139/b57-023

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

Burrillia acoriDearn. is shown to be onSparganium; it is apparently not a smut, but fresh material is needed for adequate study.Entyloma circaeaeDearn. is shown to beE.arnicaleonArnicaaffin.cordifolia. The following range or host extensions are recorded:Cintractia luzulae, Alaska;C.taubertiana, Que., N.B.;Doassansia epilobii, B.C.;D.martianoffiana, B.C.;D.sagittariae, B.C.;Entyloma clintonianum, B.C.;E.compositarum, Labr.;E.winterionDelphinium brownii, Alta., B.C.;Thecaphora deformans, Alta., Sask.;Thecaphora trailliionCirsium undulatum, B.C.;Urocystis anemonesonRanunculus cooleyaeandR.eschschollzii, B.C.;U.sorosporioidesonAconitum delphinifolium, B.C.;U.heucheraeonSaxifraga tolmici, B.C.;Ustilago bullataonBrowns ciliatus, Que.;U.tenuisporaonPolygonum hydropiperoides, Ont., andP.punctatum, N.Y.;U.violaceavars. onArenaria lateriflora, B.C. and Ont., onLychnis triflora, Ellesmere I., onSilene acaulisvars., Spitzbergen, B.C., and Que., onS.douglasiivar.villosa, B.C.;Ustilago pinguiculaeonPinguicula villosa, Man., onP.vulgaris, B.C., Alta., and Ont.

ISSN:0008-4026    

DOI:10.1139/b57-024

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

By means of the leaf-grafting technique, attempts were made to transmit the two component viruses of raspberry mosaic, rubus yellow-net, and black raspberry necrosis, separately and in combination, to three strains ofFragaria vescaL. Only the rubus yellow-net virus was transmitted to the strawberry and it induced severe symptoms. Neither the raspberry aphid,Amphorophora rubiKalt., nor the strawberry aphid,Pentatrichopus fragaefolii(Ckll.), transmitted the yellow-net virus from raspberry to strawberry, althoughA.rubiwas able to transmit the virus from strawberry back to raspberry.

ISSN:0008-4026    

DOI:10.1139/b57-025

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

The production of toxic substances byHelminthosporium sativumP.K. & B. on a variety of artificial media was evaluated by means of a barley seed germination test. The results suggest that these substances also limit the growth of the organism itself giving a fixed maximum level of toxin production. Destruction of toxin and renewed production continue until some other factor of the medium limits further growth, and culture filtrates then rapidly become inactive. The toxins are relatively nonspecific and appear to affect susceptible hosts by conditioning them to invasion by the organism. A loose correlation was found to exist between toxin production and pathogenicity in a limited number ofHelminthosporiumstrains. Even in the presence of abundant toxin, however, these strains differed in their ability to invade barley seedlings indicating that factors other than toxin production were also involved in pathogenicity.

ISSN:0008-4026    

DOI:10.1139/b57-026

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

Nodulated plants ofShepherdia canadensishave been raised in solution culture and shown to be able to grow and increase their nitrogen content in a solution free of combined nitrogen. A fixation of atmospheric nitrogen by the nodules is indicated by the data obtained, and under the prevailing conditions it attained a maximum of about 8 mg. per plant during the first season of growth from seed. The nodule development was secured by the application of an inoculum prepared from nodules of the related genusHippophaë. Nodulation occurred at pH 6 and 7 but not at pH 5; it was also suppressed by the presence of small amounts of combined nitrogen in the culture solution. The capacity of the nodulatedShepherdiaplant to fix nitrogen is probably of ecological importance.

ISSN:0008-4026    

DOI:10.1139/b57-027

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

Four hundred and twenty-one isolates ofClaviceps purpureafrom 38 different host species were cultured on an artificial medium. The conidial cultures were used to inoculate rye, wheat, and barley growing in the greenhouse. All cultures, except one fromGlyceria borealis, infected the three host species. Honeydew from rye was used to inoculate 46 gramineous species in the field and in the greenhouse. Every one of these grasses became infected in both locations. It is shown that all indigenous and forage grasses constitute a reservoir of ergot inoculum for rye, wheat, and barley, and that these cereals can be infected provided the environmental conditions are such that inoculum will be disseminated at the time that the cereal crops are in blossom.

ISSN:0008-4026    

DOI:10.1139/b57-028

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

Four new species ofChlamydomonasare described.C.euryalewas isolated from sea water;C.mexicana,C.philotes, andC.ulvaënsiswere isolated from soil.C.mexicanais heterothallic. andC.philoteshomothallic.

ISSN:0008-4026    

DOI:10.1139/b57-029

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

The structure is described for three new species of coniferous woods from Cretaceous formations in the Canadian Arctic which differ in various features from fossil woods previously recorded.Cedroxylon disjunctumsp. nov. is distinguished by gaps in cell continuity in the marginal rows of the xylem rays, a characteristic not hitherto described forCedroxylonbut found in living conifers such asAbiesandKeteleeria. The twoPiceoxylonwoods possess resin ducts devoid of tylosoids, the ducts inPiceoxylon christopherisp. nov. having an epithelium which consists entirely of thick-walled, pitted cells, whereas inP.thomsonisp. nov. the walls of the epithelial cells vary from slightly to moderately thickened.

ISSN:0008-4026    

DOI:10.1139/b57-030

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

A method involving the use of a detergent and boron has been developed for the introduction of C14-labelled sugars into leaves. This method was used for translocation studies.In the light, translocation of sucrose-C14or glucose-C14out of the treated leaf was very slow. Only 1% of the C14from sucrose was translocated after 14 hours. In the dark, 10% of the C14from glucose was translocated to all parts of the seedling in 3 hours. The bulk of the translocated C14accumulated in the stem between the treated leaf and the root. The actively growing stem tip accumulated very little C14in either light or dark.In light or dark, C14from a primary leaf that had been allowed 15 minute photosynthesis in C14O2spread throughout the entire plant in 3 hours. In light, more C14from photosynthate accumulated in the growing stem tip than in the root. This situation was reversed in the dark.

ISSN:0008-4026    

DOI:10.1139/b57-031

出版商:NRC Research Press    

年代:1957

数据来源: NRC