摘要:

A list of 66formae specialesofFusarium oxysporumSchl. emend. S. & H. pr. p. is presented with their synonymy and hosts. Nine of these are new combinations and five are designated as newformae speciales. The present status offormae specialesas a taxon outside of the International Code of Botanical Nomenclature is discussed.

ISSN:0008-4026    

DOI:10.1139/b65-138

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

The presence of 40 weeds was recorded on 130 sites from Lake Huron, Ontario, to Bangor, Maine. From the occurrence and abundance on these sites, an estimate of a weed's nuisance value was determined. Each site was analyzed for nine physical factors thought to influence the presence of these taxa. The preference of each taxon for each site factor has been recorded in a composite table. The presence of specific weeds as indicative of site conditions in abandoned pastures is discussed.

ISSN:0008-4026    

DOI:10.1139/b65-139

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

The fine structure in the carpophore of the mushroom,Agaricus campestris, was studied with the electron microscope. The stipe consists of two types of cells (i) fundamental and (ii) long and thread-like. The pileus contains only the first type. The tramal cells of the gills are more elongated than broad, regularly arranged, and rich in cytoplasmic contents. The cross wall of the hyphal cells shows a conspicuous pore apparatus with dark septal swellings encased in the plasma membrane. The nuclear membranes are differentiated early during nuclear division and are highly alveolated around the interphase nucleus. In the maturing basidium, the mitochondria increase in number by division of pre-existing ones, and thus become small with few cristae. Numerous vacuoles appear in the upper portion of the basidium. Oil globules are also produced in the mature basidium but were not observed during the early stages of development of the basidium or in any other part of the carpophore. The young basidium has food reserve which is granular in nature. The basidiospore contains numerous large oil globules, few mitochondria, scanty endoplasmic reticulum, and a wall of three well-defined layers.

ISSN:0008-4026    

DOI:10.1139/b65-140

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

One hundred and fourteen isolates ofVerticilliumspecies were tested for production of gibberellin-like substances ("gibberellins") using dwarf mutant seedlings ofZea mays. Twenty-one isolates induced statistically significant growth increases attributed to "gibberellins". Activity was observed in isolates ofV. albo-atrum, V. dahliae, V. nigrescens, andV. lateritium, from various hosts, and from various locations in Canada, United States, and Great Britain. "Gibberellin" was apparently produced also by isolates ofColletotrichum, Chaetomium, Penicillium, andRhizoctonia solani. "Gibberellin" may be produced commonly by isolates ofVerticillium, and possibly by other fungi as well.Some isolates ofVerticilliumapparently produced substances which inhibited growth of dwarf-mutant corn seedlings.

ISSN:0008-4026    

DOI:10.1139/b65-141

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

The pyrenomyceteClathridium tostum(Berk. & Broome) n. comb, is transferred fromLejosphaerellav. Höhnel (=ParadidymellaPetrak). Collections of this species on stems ofEpilobium rosmarinifoliumHoenck from France, and on stems ofEpilobium angustifoliumL. from Canada, produced in culture the conidial stateSeimatosporium kriegerianum(Bres.) Morgan-Jones & Sutton in Sutton, which, asMonoceras kriegerianum(Bres.) Guba, is the type ofMonocerasGuba.

ISSN:0008-4026    

DOI:10.1139/b65-142

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

Fourteen species (six genera) of wood-rotting basidiomycetes cultured in a chemically defined medium were examined for the presence of sterol material. These fungi were found to contain ergosterol in amounts that ranged in value from 0.017 to 0.42% of their mycelial dry weights. Such values are, in general, comparable to sterol values reported for other fungi.The synthesis of sterol byFomes meliaewas found to accompany active growth of the fungus and was quantitatively influenced by the composition of the growth medium. Hexose supported greater production of sterol than did pentose, and organic nitrogen was superior to inorganic nitrogen in respect to this synthesis. The combination of hexose and organic nitrogen supported the greatest synthesis of sterol.

ISSN:0008-4026    

DOI:10.1139/b65-143

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

A number of unusual grass plants were discovered in the fall of 1964 along Cottonwood Creek in the Cook Inlet area of south central Alaska. The occurrence, morphology, and sterility of these plants suggest that they are hybrids betweenElymus mollisTrin. andHordeum brachyantherumNevski. Meiotic irregularities were adequate to explain the complete sterility observed. The name ×Elymordeum littoraleHodgson and Mitchell was proposed for this heretofore undescribed hybrid.

ISSN:0008-4026    

DOI:10.1139/b65-144

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

Specific activity (counts per minute per gram dry matter) measurements, autoradiographs, and densitometer tracings on the autoradiographs indicated that P32, injected into the stem of wheat plants, moved rapidly into the root system and was distributed uniformly throughout it. Although root weights varied with depth, the specific activity of the washed root material remained relatively constant.The stage of plant growth markedly influenced the translocation of the P32into the roots. Quantitative measurements indicated that approximately five times as much activity moved into the root systems of 40-day-old compared with 60-day-old plants. A soil moisture stress increased the specific activity of the roots.A linear increase in the specific activity of the root material was obtained by-increasing the number of tillers injected per wheat plant (amount injected constant). The addition of indoleacetic acid, NH4H2PO4, or H3PO4to the carrier-free P32reduced, rather than increased, movement to the roots.

ISSN:0008-4026    

DOI:10.1139/b65-145

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

Axenic cultures of 38 organisms, half of these available from culture collections of algae and half newly isolated, were investigated for nitrogen utilization. When NaNO3, NaNO2, (NH4)2SO4, and NH4NO3were used as sole sources of nitrogen in an organic basal medium, it was evident that most of the organisms used NaNO3and NaNO2with equal facility. (NH4)2SO4was utilized to about the same extent as NH4NO3, and both were used with less facility than NaNO3and NaNO2. Growth in the basal medium with any of nine amino acids as sole nitrogen sources (namely, asparagine, ornithine, aspartic acid, lysine, serine, glycine, glutamic acid, alanine, and glutamine) was sufficiently differential to suggest possible taxonomic utility. When study was made of certain nitrogenous bases as sole nitrogen sources, it was found that adenine and uric acid were widely utilized, but cytosine, thymine, and uracil supported little or no growth. Again, when acetamide and succinamide were used as sole sources of nitrogen, and growth was compared with that in media containing glutamine and asparagine, patterns of growth differed from organism to organism. In summary, it can be said that these experiments provide data on growth patterns which may be significant as supplements to strictly morphological attributes of the organisms.

ISSN:0008-4026    

DOI:10.1139/b65-146

出版商:NRC Research Press    

年代:1965

数据来源: NRC

摘要:

An account is given of the cytological phenomena associated with zygospore maturation and germination, including meiosis, in the homothallic desmidCosmarium botrytisvar.tumidum, and also of meiosis in the heterothallicC. botrytisvar.botrytis. Evidence was obtained for the absence of localized centromeres in the chromosomes. In both strains the first meiotic division is asynchronous, some chromosomes moving towards the spindle poles while others are still present as incompletely terminalized bivalents.A count of 2n = 40 chromosomes in the heterothallic variety confirmed a mitotic count ofn = 20. After meiosis, two non-sister nuclei abort.

ISSN:0008-4026    

DOI:10.1139/b65-147

出版商:NRC Research Press    

年代:1965

数据来源: NRC