摘要:

Fifty-two species of lichens were found onLarix lyalliiParl. andPinus albicaulisEngelm. trees in 31 stands in the subalpine zone of the mountains of southwestern Alberta. The species belong to the following North American distributional elements: 25, Pan Boreal; 13, Arctic Boreal; 8, Cordilleran or Western Boreal; 2, Pan North American; 2, Eastern Boreal; and 1, uncertain.InLarix lyallii, quadrats occupying the lower 30 cm of the trunk were characterized by aParmeliopsis hyperopta–P. ambigua–Cetraria pinastriunion whereas quadrats in a region 40 cm deep, centered at 1.3 m from the base, were occupied by aLetharia californica–Alectoria glabraunion. InPinus albicaulis, the lower quadrats were characterized by aParmeliopsis ambigua–Cetraria pinastri–Parmeliopsis hyperopta–Lecidea fuscescensunion whereas the upper were occupied by aParmelia sphaerosporella–Letharia californica–Lecanora varia–Alectoria glabraunion.Forty-eight species occurred on the smooth to rough, more absorbent, bark ofPinus albicauliscompared with 32 found on the rough bark ofLarix lyallii.Succession followed four stages: (1) the invasion of appressed foliose lichens on the tree bases, (2) the appearance of crustose species on the lower four feet of the trunk, (3) the invasion of foliose species on the trunk and branches, and (4) the appearance of fruticose species.

ISSN:0008-4026    

DOI:10.1139/b69-091

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Low tryptophan synthase (L-serine hydro-lyase (adding indole), EC 4.2.1.20) activity in extracts of pea roots is a consequence of both a low concentration of the enzyme in roots and the presence of inhibitors at least some of which may be removed by homogenizing the fresh tissue with acetone. Inhibition by root extracts, and fractions thereof, was assayed against tryptophan synthase from seedling buds. At least three inhibitory components were detected, namely (1) a dialyzable, thermostabile component, (2) an undialyzable, thermolabile component, and (3) an undialyzable, thermostabile component. A dialyzable factor which protects an undialyzable inhibitory factor against heat inactivation is also indicated.Fractionation of crude root extracts by gel filtration on a column of Sephadex G-50 shows inhibitor with a molecular weight of about 10 000 or larger.

ISSN:0008-4026    

DOI:10.1139/b69-092

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Chromosome numbers are given for 58 plant taxa of the Yukon Territory, especially from the unglaciated areas in the Ogilvie Mountains. The chromosome numbers of the following taxa were previously unknown:Rumex arcticusTrautv., 2n = 40;Claytonia arcticaAdams, 2n = 10;Arenaria arcticaStev., 2n = ca. 80;Arenaria physodesFisch.exDC., 2n = 66;Melandrium taylorae(Robins.) Tolm., 2n = 48;Ranunculus gelidusKar. & Kir., 2n = 16;Ranunculus sceleratusssp.multifidus(Nutt.) Hult., 2n = 64;Ranunculus purshiiRichards., 2n = 64;Thalictrum sparsiflorumTurcz. var.richardsonii(Gray) Boivin, 2n = 14;Chrysosplenium wrightiiFranch. & Sav.,n = 12 and 2n = 24;Saxifraga adscendensssp.oregonensis(Raf.) Bacigalupi,n = 11;Saxifraga punctataL., 2n = ca. 84;Saxifraga radiataSmall,n = 13;Dryas alaskensisPorsild, 2n = 18;Geum rossii(R. Br.) Sér., 2n = 70;Potentilla ledebourianaPorsild,2n = 28;Oxytropis huddelsoniiPorsild, 2n = 16;Epilobium ciliatumRaf., 2n = 36;Penstemon gormaniiGreene, 2n = 16;Synthyris borealisPennell, 2n = 24;Arnica lessingiiGreene, 2n = 57.

ISSN:0008-4026    

DOI:10.1139/b69-093

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Cambial explants of western white pine,Pinus monticola, infected withCronartium ribicola, were cultured on a medium containing glucose, calcium nitrate, magnesium sulfate, potassium phosphate (monobasic), ammonium sulfate, ferric sulfate, manganese sulfate, and one of three auxins: indoleacetic acid (IAA), naphthaleneacetic acid (NAA), or 2,4-(dichlorophenyoxy)acetic acid (2,4-D).Invasion of newly formed callus tissue by the rust fungus was generally slow. Dense, feltlike aerial mycelia were frequently produced. Intercellular mycelia and intracellular haustoria were typical, and direct attachments to aerial mycelia were observed. Occasionally, mycelia invaded the medium, but did not become independent of the host tissue. Typical pycnia- and aecia-like sori were produced in many cultures. Aecia-like sori formed immediately after maturation of pycnia, but did not produce spores.

ISSN:0008-4026    

DOI:10.1139/b69-094

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

The use of carbon dioxide, acetate, and leucine in the synthesis of lamellar lipoprotein was investigated in chloroplasts ofNicotiana tabacumL. seedlings. These14C-labelled substrates were fed to sterile seedlings and lamellae were isolated from seedling chloroplasts. The major lamellar lipoprotein was extracted by continuous-flow polyacrylamide gel electrophoresis and the lipoprotein was separated into protein and lipid fractions.All of the substrates were incorporated into both protein and lipid. Carbon dioxide and acetate incorporation was more strongly light dependent than leucine. Light–dark and protein–lipid incorporation ratios were established for each substrate. Leucine label was found in many lamellar amino acids.

ISSN:0008-4026    

DOI:10.1139/b69-095

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Shrinkage of plant protoplasts in hypotonic solutions or even in distilled water has been long known as an erratic response to injury. Although the mechanism for it is not known, this phenomenon, termed "induced", "stimulative", or "false" plasmolysis, has been considered to be comparable to spore formation in algae and fungi or to vacuolar contraction in protozoa. Studies of the mechanism of false plasmolysis have been precluded by the inability to induce the phenomenon consistently in large numbers of cells. Victorin treatment of root cap cells from Victoria-blight susceptible oats was found to result consistently in false plasmolysis. Ultrastructure studies of such cells showed that synthesis of new membranes was not involved in victorin-induced false plasmolysis. Discontinuities in the plasmalemma and tonoplast rule out active movement of water as a causative factor for protoplast shrinkage. The mechanism responsible for false plasmolysis appears to be an increased permeability of membranes to water, followed by disruption of the vacuole and a reduction of plasmalemma area by a process similar to pinocytosis.

ISSN:0008-4026    

DOI:10.1139/b69-096

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Two proteins, previously described by the authors as BI (S020,buffer12 S) and AIVS (S020,w1.7 S) have been isolated from eight varieties of rapeseed belonging toBrassica campestrisL. andBrassica napusL. species. These proteins have similar chromatographic and electrophoretic characteristics but differ in amino acid composition, particularly with regard to the sulfur-containing amino acids. One of the rapeseed samples was obtained from plants grown on sulfur-deficient soil. The sulfur deficiency produced, in the mature seed, a much reduced protein content and appeared to affect the structure of the protein BI.

ISSN:0008-4026    

DOI:10.1139/b69-097

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Physiological and biochemical studies were made of the extractible rooting cofactors from juvenile and mature growth phases ofHedera helix, English ivy. An extraction procedure involving 100, 95, 80, and 60% ethyl alcohol was adopted for general use. The number and concentration of rooting cofactors in the leaves, stems, and roots were determined. Elution of cofactor 4 (oxygenated terpenoids) from a silica gel column, with increasing amounts of ethyl acetate in hexane, resulted in five major fractions and several minor ones. High levels of chlorogenic and isochlorogenic acids were found in all tissues, while traces of caffeic and ferulic acids were detected only in the roots. The decreasing order of plant parts from both growth phases for total chlorogenic and isochlorogenic acids was leaves, roots, and stems; this pattern also applied to total phenol content of the plant parts. Chlorogenic acid was a component of rooting cofactor 2. Rooting cofactor 3 had at least three constituents: chlorogenic and isochlorogenic acids, and an unknown promoter (P-257). The effects of caffeic, chlorogenic, isochlorogenic, and quinic acids with indoleacetic acid in the rooting bioassay were similar and not very large at a concentration of 5 × 10−4 Mor lower. No active component of rooting cofactor 1 was identified.

ISSN:0008-4026    

DOI:10.1139/b69-098

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

A chemical and morphological alteration of the epidermal wall of barley, clover, strawberry, and sunflower occurred around the infection peg ofErysiphe graminis, E. polygoni, Sphaerotheca macularis, andErysiphe cichoracearumrespectively while the peg was passing through the epidermal wall. A disc-shaped area with the peg as the central point always stained more heavily than other zones after epidermal strips were treated with azure dyes and cotton blue. The "classic" zinc–chlor–iodide and the IKI–H2SO4cellulose tests indicated that cellulose was lacking in the disc-shaped zone. This zone stained only faintly with the periodic acid – Schiff's test, indicating that the amount of polysaccharide was reduced around the penetration tube. After differential extraction of polysaccharides the PAS-negative halo was always surrounded by a PAS-positive band even after pectin, hemicellulose, and noncellulosic polysaccharides had been removed. Electron micrographs showed that the morphology was altered and electron density was increased in the disc-shaped zone. Sometimes the altered zone was swollen. Thus, the cytochemical tests and electron micrographs suggest very strongly that the cellulose wall in the zone around the infection peg is degraded by enzyme(s), such as cellulase, produced by powdery mildews.

ISSN:0008-4026    

DOI:10.1139/b69-099

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Pea seeds soaked in sterile water for 2 days at 20 °C showed no adverse effects. If seeds are soaked longer seedling development is retarded, roots are shorter, and stem tissue deteriorates. Seeds soaked 2 and 3 days show a maximum rate of root growth in excess of the maximum growth rate exhibited by seeds soaked for 1 day. Increasing the soaking time tends to delay the utilization of stored food in the cotyledon.

ISSN:0008-4026    

DOI:10.1139/b69-100

出版商:NRC Research Press    

年代:1969

数据来源: NRC