摘要:

The type species of the generic nameVerticicladiellaHughes,V. abietina(Peck) Hughes, is illustrated and redescribed. Six other species, four of which are new, are also included in this genus of hyphomycetes, which is distinguished fromLeptographiumby its different method of conidium development. Species ofVerticicladiellaare usually collected on, or isolated from, wood of conifers, and are often associated with bark-beetle attacks and blue stain. One of the new species secretes an antibiotic substance, and another causes a severe root disease in some species ofPinusin the southwestern United States.

ISSN:0008-4026    

DOI:10.1139/b62-072

出版商:NRC Research Press    

年代:1962

数据来源: NRC

摘要:

Scaphytopius acutus(Say) transmitted a celery-infecting strain of aster-yellows virus from infected periwinkle (Vinca roseaL.) and aster (Callistephus chinensisNees) to periwinkle, aster, and ladino clover (Trifolium repensL.). It acquired the virus during feeds as short as 4 hours, and transmitted it during a 2-hour feeding period. The minimum incubation time for the virus in the insect was between 21 and 26 days. After an acquisition feed of 7 days and an incubation period of at least 30 days, 11 of 21 insects transmitted the virus to separate periwinkle test plants.

ISSN:0008-4026    

DOI:10.1139/b62-073

出版商:NRC Research Press    

年代:1962

数据来源: NRC

摘要:

C14-mannitol was supplied to fronds ofF. vesiculosus, and its conversion into CO2and other compounds was studied. Only small amounts of the mannitol taken in were metabolized. Mannitol is apparently not an immediate substrate of respiration, but in time it may be converted into some other substances which are. Dilute acid-soluble polysaccharides acquired small amounts of radioactivity, but most of the mannitol which underwent metabolism was eventually converted to residual carbohydrates. It is concluded that mannitol is probably a storage compound rather than an active metabolite.

ISSN:0008-4026    

DOI:10.1139/b62-074

出版商:NRC Research Press    

年代:1962

数据来源: NRC

摘要:

This taxonomic study of the hyphomycete genusDrechslerais based on type specimens, and on fresh collections and herbarium specimens principally from North America. Characters of conidia and conidiophores, and the growth characteristics of the species in artificial culture, are described and illustrated. Two keys to species are included: one based on characters of conidia and conidiophores; the second based on growth characteristics on sucrose proline agar. Fifteen species, one composed of two formae speciales, are accepted. Their names and some of the well-known synonyms are:D. avenacea(Curtis ex Cooke) Shoem. (=Helminthosporium, avenaeEidam);D. bromi(Died.) Shoem.;D. catenaria(Drechs.) Ito;D. dactylidisn. sp.;D. dictyoides(Drechs.) Shoem. f. sp.dictyoides; D. dictyoidesf. sp.perenne(Braverman & Graham) n. comb.;D. erythrospila(Drechs.) Shoem.;D. fugax(Wallr.) Shoem. in Hughes (=H. stenacrumDrechs.);D. gigantea(Heald & Wolf) Ito;D. graminea(Rab. ex Schlecht.) Shoem.;D. phlei(Graham) Shoem.;D. poae(Baudys) n. comb. (=H. vagansDrechs.);D. siccans(Drechs.) Shoem.;D. teres(Sacc.) Shoem.;D. tritici-repentis(Died.) Shoem. (=Drechslera tritici-vulgaris(Nisikado) Ito); andD. tuberosa(Atk.) Shoem. (=H. secalisWhitehead & Dickson, =H. japonicumIto & Kurib., =H. fragosoiBubak). Also included are the perfect states of six species:Pyrenophora chaetomioidesSpeg. (st. conid.D. avenacea);P. bromi(Died.) Drechs. (st. conid.D. bromi);P. teresDrechs. (st. conid.D. teres);P. tritici-repentis(Died.) Drechs. (st. conid.D. tritici-repentis);P. japonicaIto & Kurib. in Ito (st. conid.D. tuberosa), and the perfect state ofD. dactylidis.

ISSN:0008-4026    

DOI:10.1139/b62-075

出版商:NRC Research Press    

年代:1962

数据来源: NRC

摘要:

Valsa myindaCooke and Ellis is correctly placed in the genusValsa. The specimens described under the nameCryptodiaporthe myinda(Cooke and Ellis) Wehmeyer belong to a different species that is properly placed in the genusCryptodiaportheand for which there is no valid species name available.Cryptodiaporthe acerinumsp. nov. is therefore proposed for this fungus, with collections available from New York, New Jersey, West Virginia, and Ontario. All of the collections of these two species are onAcer.

ISSN:0008-4026    

DOI:10.1139/b62-076

出版商:NRC Research Press    

年代:1962

数据来源: NRC

摘要:

A new fixative, which is composed of butyl alcohol, acetic acid, and chromic acid, is introduced. This BAC mixture fixes nuclear details, and cytoplasm is not granulated to any extent. Details of staining procedures and helpful hints for successful staining are given. This improved technique differentiates all stages of nuclear division from interphase to interphase in the vegetative hyphae of fungi as well as in the sexual stage. Chromosomes, nucleoli, and centrioles are clearly shown. A series of mitotic figures in germ tubes ofNeurospora crassaand some meiotic figures inGelasinospora calosporaare attached as illustrations.

ISSN:0008-4026    

DOI:10.1139/b62-077

出版商:NRC Research Press    

年代:1962

数据来源: NRC

摘要:

A certain daylength treatment inhibited the growth of northern seedlings ofPinus resinosaandThuja occidentalismore than it inhibited southern seedlings of these species. These treatment – seed source interactions were small, but otherwise similar to those found earlier in 29 northern tree species. The smallness of the interaction was caused by the overruling effect of the endogenously determined growth pattern inP. resinosa, and by the lack of large photoperiodic response inT. occidentalis.The broad subject of ecotypic variation in the photoperiodism of trees is discussed. The evolution of dormancy mechanism suggests that photoperiodism should tend to be overruling in the truly northern trees, and the endogenous rhythm in trees from the middle latitudes.

ISSN:0008-4026    

DOI:10.1139/b62-078

出版商:NRC Research Press    

年代:1962

数据来源: NRC

摘要:

A new speciesChaetomium fusisporaleRai & Mukerji, isolated from usar soils of Lucknow (India), is described. It has straight hairs and fusiform ascospores with a single germ pore.

ISSN:0008-4026    

DOI:10.1139/b62-079

出版商:NRC Research Press    

年代:1962

数据来源: NRC

摘要:

Plastids were investigated in ultrathin sections of young developing tissues of corn endosperms, pea cotyledons, and potato. The electron photographs give support to the possibility that plastids are producedde novo, as well as by division. Some of the pictures suggest that, under certain conditions, plastids may also multiply by a process of delimitation brought about by invaginations of the plastid membrane.Several aspects of plastids and mitochondria can be directly compared, but the latter are much more limited in their response to environmental changes. An originde novofor plastids is in agreement with known genetical behavior and results of recent biochemical investigations.

ISSN:0008-4026    

DOI:10.1139/b62-080

出版商:NRC Research Press    

年代:1962

数据来源: NRC

摘要:

Six species ofFragariatogether with their subspecific entities are described and typified, and their chromosome number is given. A total of 392 collections have been investigated cytologically. So far as it seemed necessary for interpretation, historical notes are added. The following taxa are discussed:F. vesca(four subspecies, five forms, three cultivars),F. viridis, F. moschata, F. virginiana(four subspecies),F. chiloensis(four subspecies, two forms),F. ×ananassa(two nothomorphs). New status is given to numerous taxa and two new taxa are described.

ISSN:0008-4026    

DOI:10.1139/b62-081

出版商:NRC Research Press    

年代:1962

数据来源: NRC