摘要:

Typical cankers with stromata were produced when aspen were inoculated with isolates ofHypoxylon mammatum(H. pruinatum) from aspen, but isolates from alder and willow were incapable of producing typical cankers on aspen. Isolates from willow produced cankers initially, but these were eventually callused over. Isolates from alder and aspen were not able to incite cankers on alder. Dimensions of the perithecia and ascospores of the fungus on aspen are not sufficiently different from those on birch, willow, and alder to justify maintainingH. pruinatumas a species separate fromH. mammatum.

ISSN:0008-4026    

DOI:10.1139/b69-029

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

The ultrastructure of zoospores ofOlpidium brassicae(Wor.) Dang. is described. The zoospores resemble other uniflagellate zoospores in many respects, but ribosomes occur throughout the zoospore body while mitochondria occur only around the nucleus. The axoneme seems to lack a terminal plate, and the rhizoplast differs markedly from that in other chytrid zoospores. The rhizoplast is a cross-banded structure that tapers from 350 mμ wide where it fits against the anterior end of the centriole and kinetosome to 150 mμ near the nucleus; its length is 1 μ. Some zoospores have two or three nuclei, and the origin of these zoospores is discussed.

ISSN:0008-4026    

DOI:10.1139/b69-030

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Crystalline inclusions are reported for the first time in the chloroplast of an alga. The cryophilic chlorophycean alga, isolated from snow, lacks a pyrenoid and is tentatively identified as a species ofChlamydomonas. The inclusions are similar to those reported in higher plants and are more abundant in material grown at the optimum temperature of 5 °C. The possibility of a proteinaceous nature of the inclusions is briefly discussed.

ISSN:0008-4026    

DOI:10.1139/b69-031

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Infrared gas analyzer techniques were used and the carbon dioxide gas exchange of attached red kidney bean and sunflower leaves was measured in an open gas stream. The glycolate oxidase activity of the leaf homogenates was manometrically determined. It was concluded that the maximal rates of photorespiration and glycolate oxidase activity have the same order of magnitude.

ISSN:0008-4026    

DOI:10.1139/b69-032

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

A comparative study was made of the fungitoxic and phytotoxic properties of an homologous series of sodiumN-alkyldithiocarbamates with 1 to 10 carbon atoms in the alkyl group. The ethyl, propyl, and butyl homologues were comparable to the methyl form (SMDC) in toxicity toMonilinia fructicola, while the amyl and hexyl were less active. A further increase in the carbon chain up to the decyl increased fungitoxicity correspondingly. Germination of barley seeds was inhibited progressively less from the methyl to the heptyl, slightly more by the octyl, and least by the decyl. None of the compounds had any apparent effect on tomato foliage at 10 mM, but when applied to cut stems of tomato or roots of tomato, barley, or cucumber many of the treatments induced wilting, leaf necrosis, and stem collapse. Quantitative data on both fungitoxic and phytotoxic effects were obtained from the emergence of peas planted in sand–vermiculite infested to various degrees withPythium ultimumand drenched with a series of concentrations of each chemical. SMDC and the ethyl homologue were the most effective in controlling preemergence damping-off, the propyl through octyl progressively less effective, and the nonyl and decyl completely ineffective. Non-emergence due to chemical damage decreased from the methyl to the amyl homologue but increased from the octyl to the decyl.

ISSN:0008-4026    

DOI:10.1139/b69-033

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Cyathusin the Nidulariales and seven species in five genera of Lycoperdales includingBattarrea, Calbovista, Calvatia, Lycoperdon, andTulostomaare reported from the Yukon Territory and adjacent Alaska. Descriptions and notes of each species are given and accompanied by photomicrographs of the salient microscopic characters. Macrophotographs of four species are included.

ISSN:0008-4026    

DOI:10.1139/b69-034

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Fourteen species of fungi are reported on submerged leaves ofPrunus laurocerasusandArbutus menziesii. Nowakowskiella elegans(Nowak.) Schroeter is reported from the ocean for the first time.Phytophthora vesiculasp. nov. is described and is reported to be extremely common on leaves in the marine environment. The relationship ofP. vesiculato other species of the genus is discussed.

ISSN:0008-4026    

DOI:10.1139/b69-035

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Three megasporangiate cones apparently formed directly by shoot apical meristems were found in a terminal position on a pinyon pine (Pinus edulisEngelm.).

ISSN:0008-4026    

DOI:10.1139/b69-036

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

A new pathogen of spruce (Piceaspp.) needles is described. Although difficult to distinguish macroscopically from similar parasites, its short ascospores facilitate identification under the microscope. Its geographic distribution and importance as a cause of needle blight are still uncertain.

ISSN:0008-4026    

DOI:10.1139/b69-037

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

The peroxidase isozymes from the first leaf of seven varieties of wheat of different levels of cold hardiness have been studied by agar gel electrophoresis. The plants were grown under controlled conditions at 6 °C or 20 °C. The isozyme pattern changes during ontogeny. The intensity of staining of the fastest moving "anionic" band is much greater in the leaves of the common wheats grown at 6 °C than in similar leaves from plants grown at 20 °C. This increase in peroxidase is apparently not associated with cold hardiness.

ISSN:0008-4026    

DOI:10.1139/b69-038

出版商:NRC Research Press    

年代:1969

数据来源: NRC