摘要:

Vestigium, a new genus of acervular, staurosporous Coelomycetes is proposed forV. felicis, a new species occurring onThujain the Pacific Northwest.

ISSN:0008-4026    

DOI:10.1139/b72-141

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The amino acid requirements of subcultures of the wheat stem rustPuccinia graminisf. sp.triticihave been determined. These isolates will grow on an agar solidified medium containing Czapek's minerals, glucose, citrate, cysteine, and one of the following nitrogen sources: ammonium, aspartate, asparagine, glutamate, glutamine, alanine, serine, and glycine, but not nitrate or nitrite. Cysteine can be replaced by homocysteine or methionine, but not by inorganic forms of sulfur. Possible reasons for the requirement of these organic sulfur compounds are discussed.

ISSN:0008-4026    

DOI:10.1139/b72-142

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Plants ofCosmos bipinnatusCav. "Sensation" (a quantitative short-day plant) were grown under continuous conditions of long days to maintain the vegetative state. The vegetative apex shows a cytohistological zonation pattern superimposed upon a tunica–corpus organization. The biseriate tunica is separated into two zones: axial and lateral; while the corpus is separated into three zones: the peripheral, central, and rib meristem. Based on mitotic activity (both frequency and index) there is neither a "méristème d'attente" nor an "anneau initial" present. A double plastochron cycle is present because of the decussate leaf arrangement and the presence of prominent leaf bases. Cytohistological zonation, nucleolar volume, RNA content, and mitotic index vary in a cyclic manner with the phase of plastochron. Although the degree of zonation decreases just after leaf buttress initiation, zonation does not disappear at any time during a plastochron.

ISSN:0008-4026    

DOI:10.1139/b72-143

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Changes in invertase activity and growth were examined in excised rice coleoptile sections which were treated with water, gibberellic acid (GA3), sucrose, and GA3+ sucrose. Invertase activity with all treatments rises in parallel during the first 6 h. Between 6 and 12 h, the GA3and GA3+ sucrose treatment causes the invertase activity to increase at a faster rate than the respective water and sucrose controls. For all treatments, the peak invertase activity occurs at 12 h; it then declines rapidly between 12 and 24 h. After this, the enzyme activity becomes stable by 36 h for sucrose and GA3+ sucrose treatments. In contrast, in water and GA3treatments, the enzyme activity continues to decrease up to 48 h, then attains a steady state level. With water, GA3, sucrose, and GA3+ sucrose, there is a close correlation between the time of maximal invertase activity and the time of maximal growth rate (12 h), and the kinetics for promotion of both processes are essentially the same. This study indicates that both GA3and sucrose may be involved in regulating levels of invertase and that invertase activity is closely associated with growth in rice coleoptile sections.

ISSN:0008-4026    

DOI:10.1139/b72-144

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Six species and one variety are recognized in a worldwide study of the genusDrummondia. The genus is placed in its own subfamily, theDrummondoideaeVitt, most closely related to the Macromitrioideae. The new combinationDrummondia sinensisvar.ussuriensis(Broth.) Vitt is made and recorded from eastern U.S.S.R. The Japanese material ofDrummondiais considered within the concept ofD. sinensisand is shown, by use of a scatter diagram, to be different from the eastern North AmericanD. prorepens. A key to the taxa is given and a complete taxonomic diagnosis is presented for each taxon with comments about its distribution and critical features. The geographical distributions of the taxa indicate that the genus was a part of a circumpolar Arcto-Tertiary flora.

ISSN:0008-4026    

DOI:10.1139/b72-145

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Mer Bleue is an ombrotrophic sphagnum and black spruce bog near Ottawa, Ontario. Its 5000 ac offer a vegetation composed of 10 associations and 3 subassociations. Day temperature in the bog is 2.7°F higher and night temperature 3.2°F lower than at Uplands Airport 7 mi away. Relative humidity is also higher. The black spruce stand is the most humid and the coolest of all plant associations and its water table is the highest, whilePolytrichumassociation is the dryest and the warmest. Black spruce stands also have the most stable climate.Temperature at 1 ft depth in the peat moss reaches a minimum of 55°F in summer. At 2 ft depth a maximum of 47°F occurs in September and a minimum of 24°F in February. The pH lies between 3.8 in ombrotrophic areas and 6.5 in minerotrophic conditions. Many other aspects are discussed.

ISSN:0008-4026    

DOI:10.1139/b72-146

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The finding of clamps throughout the tissues inPhellodon fibulatussp. nov. raises a question as to the recognition of the family Bankeraceae, characterized mainly by hyaline echinulate spores and a distinctive odor when dried. Grand and Moore have shown that the ornamentation on the spores ofPhellodonis the same as inHydnellumandHydnum, and Brady reports the presence of the thelephoric acid in the same genera. This leaves hyaline spores as the only significant difference betweenHydnellumandPhellodon. Odor of the dried specimens is considered to be of doubtful value as a family character. It is concluded that the family Bankeraceae is superfluous, and its genera are referred to the Hydnaceae.

ISSN:0008-4026    

DOI:10.1139/b72-147

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Dactylorhiza purpurellawas grown from seed in sterile cultures on agar slopes. The culture media consisted of combinations of minerals, dextrose or sucrose, the amino acids and vitamins etc. found in casein hydrolysate, and yeast extract. After an initial period of germination and growth, the cultures were treated with kinetin, kinetin riboside, 6(γ, γ-dimethylallylamino)purine, and indoleacetic acid (IAA), alone and in various combinations, primarily to simulate patterns of development previously obtained in symbiotic cultures.The results with dextrose and sucrose were essentially similar. Germination and growth in either case were markedly superior where casamino acids were present, and growth and survival were further improved with supplements of yeast extract to those media. On such media protocorm development was normal and in every respect as good as in symbiotic cultures. Aspartic, glutamic, and nicotinic acids appear to play vital roles in the nutrition ofD. purpurella.The three aminopurines tested enhanced the shoot characters and suppressed the root characters of the protocorms, and enhanced chlorophyll formation. The results with IAA were inconclusive. The growth regulators may interact with aspartic and (or) glutamic acids with respect to morphogenesis.Iron (as ammonium ferric citrate) was deficient and limiting at 0.2 mg/liter Fe. Greener shoots, better rooting, and no harmful effects were obtained with 25 mg/liter. High levels of manganese (50 mg/liter) caused severe leaf chlorosis and hindered the beneficial effects of iron on the shoots. An Fe/Mn ratio greater than unity was necessary. Within certain limits, the right ratio may be more important than the actual levels of these cations.The effects of the growth regulators should be reassessed in relation to at least aspartic and glutamic acids, iron and manganese.

ISSN:0008-4026    

DOI:10.1139/b72-148

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Balsam fir seedlings were grown under uniform conditions from seed collected along an elevational gradient in the White Mountains of New Hampshire. Photosynthetic temperature optimum of the seedlings decreased with increasing elevation of the seed source. The change in temperature optimum with elevation was similar to the adiabatic lapse rate, suggesting a precise adaptation to temperature through natural selection.

ISSN:0008-4026    

DOI:10.1139/b72-149

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Specimens ofColeus hybridus'Chartreuse' have been treated with two morphactins (IT 3233 and IT 3456) which were applied, either one or four times, to the apex of the plant or the soil beneath, at 25 or 50 ppm. The treated plants have shown inhibition symptoms in their growth at the principal axis. Generally the action of IT 3233 was minimal; on the other hand, IT 3456 has brought a well-marked reduction of the length of the axes. A factorial analysis of the measurements of the treated groups by IT 3456 has permitted the determination of two very significant factors: 'method of application' and 'frequency'; also it has shown a significant interaction between these factors. The two concentrations used did not produce effects that were significantly different.

ISSN:0008-4026    

DOI:10.1139/b72-150

出版商:NRC Research Press    

年代:1972

数据来源: NRC