摘要:

Buffer-soluble proteins extracted from 33 isolates of variousFusarium oxysporumformae speciales and 13 otherFusariumspecies were separated on polyacrylamide gel disc electrophoresis. The resulting patterns were compared and their use as a taxonomic criterion assessed. The results obtained do not support the current concept that this method is useful as a taxonomic tool.

ISSN:0008-4026    

DOI:10.1139/b69-268

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Two newly discovered ectotrophic mycorrhizae of Douglas fir (Pseudotsuga menziesii(Mirb.) Franco), each formed by a distinct strain ofPoria terrestris(DC. ex Fries) Sacc., are described. Each is named according to tree and fungus species, including strain of the latter as denoted by characteristic staining of respective sporocarps:Pseudotsuga menziesii+Poria terrestris(blue-staining) andP. menziesii+P. terrestris(orange-staining). Macro- and micro-scopic descriptions of the natural mycorrhizae, of surrounding mycelia and rhizomorphs, and of nutrient agar cultures of each fungal strain ofP. terrestrisare given. The two described strains ofPoria terrestrisare proposed for at least varietal distinction on the basis of their mycorrhizal and cultural differences.

ISSN:0008-4026    

DOI:10.1139/b69-269

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Caryopses of a dormant strain ofAvena fatuaL. fail to germinate on moist filter paper when immature whereas non-dormant caryopses germinate at 10 days after fertilization and at later stages of development. Embryos of the dormant strain excised at any stage of development fail to germinate in a complex nutrient medium which supports germination and growth of non-dormant embryos at, and after, 10 days following fertilization. Gibberellicacid (GA) promotes germination of dormant caryopses and excised dormant embryos before and at maturity in the presence of either endosperm or the nutrient medium. This requirement for gibberellin is not absolute, since germination of dormant embryos in mid-development occurs when the nutrient medium is solidified with agar in the absence of gibberellin. The stimulatory effect of solidifying the medium is probably due to differential leaching action upon embryos affecting levels of endogenous gibberellins. The genetic source of endosperm does not influence germinability of the embryo, and endosperms of both dormant and non-dormant strains show an increasing capability of supporting postgerminal growth of non-dormant embryos. A block to the use of these nutrients by the embryo, reversible by gibberellin, is present at maturity in endosperm of the dormant strain.

ISSN:0008-4026    

DOI:10.1139/b69-270

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Prediction equations are presented for use in estimating total aboveground weight and maximum leaf weight for 22 species of woody plants. Stem diameter at the ground line was found to be closely correlated with both total and leaf weights. This diameter was therefore used in the equations as the measurement from which weights were predicted.

ISSN:0008-4026    

DOI:10.1139/b69-271

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Amino acid analyses were performed on the soluble and total proteins from plant cells grown in suspension culture. The cell cultures originated from 12 different plant species, and the explants were taken from different organs of the plants.Relatively small differences in the amino acid composition existed between the soluble proteins from different species, between cells originating from different organs of the same species, and between the same cultures grown on different media under the same environmental conditions.There was some variation in the proportion of basic, aromatic, and sulfur-containing amino acids which constituted about 17%, 9.5%, and 3% of the protein amino acids, respectively. The amino acid composition of the soluble proteins of wheat coleoptile and soybean hypocotyl resembled that of the soluble proteins from cultured cells of these plants. Essential amino acids, particularly the basic ones and methionine, were proportionally higher in the cell proteins than those reported for seed proteins.

ISSN:0008-4026    

DOI:10.1139/b69-272

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Comparative morphological and palynological studies have been carried out onPlantago fastigiata(P. insularis) of the New World andP. ovata, including some closely allied species of sectionLeucopsyllium, of the Old World. As a result,P. fastigiatais regarded as conspecific withP. ovata. It is postulated that the North American populations known asP. fastigiataare introductions ofP. ovatadating from the late 18th and the beginning of the 19th century by early settlers in California.

ISSN:0008-4026    

DOI:10.1139/b69-273

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

A new combination of embedding material and high contrast stain has provided the means for demonstrating, photographically, tangential sections of endodermal cells showing complete Casparian strips.

ISSN:0008-4026    

DOI:10.1139/b69-274

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Applied auxin caused cells of artichoke tuber slices to expand and deposit significant amounts of new wall material while cells in slices held on water remained essentially inert in both respects. Cells in all physiological treatments showed multivesicular structures at the plasma membrane (plasmalemmasomes, lomasomes), within the cytoplasm and within the central vacuoles. The number of plasmalemmasomes was considerably greater in cells not depositing wall than in cells treated with auxin to stimulate wall synthesis. Multivesicular structures showed no relation to Golgi bodies, which increase in number and apparent activity in response to auxin treatment. It is concluded that plasmalemmasomes are not involved in cell wall deposition. Multivesicular structures in plant cells could have several origins and it is suggested that some may represent artifactual reorganization of plasmalemma and tonoplast membranes during cytological processing. Such reorganization would presumably be sensitive to the physiological state of the tissue.

ISSN:0008-4026    

DOI:10.1139/b69-275

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Systemic resistance was induced in the leaves ofDatura stramoniumL.,Nicotiana glutinosa, Phaseolus vulgarisvar. Prince, andChenopodium amaranticolorby localized infection with tobacco mosaic or necrosis viruses (TMV, TNV). Crude extracts prepared from the resistant leaves were more inhibitory to TNV infection onPhaseolusthan were extracts from non-resistant (control) leaves. Subsequently, crude extracts were fractionated into protein and ribonucleic acid (RNA) and inhibitory activity from resistant areas was retained in the RNA preparation. The RNA from resistant and non-resistant leaves was purified and separated into three fractions (about 27 S, 17 S, and 3 S), by gel filtration on Sephadex G-200. The 27-S and 17-S fractions from both treatments inhibited TNV infection by similar amounts. However, the 3-S RNA from resistant leaves reduced lesion number to a greater extent when compared to both the 3-S RNA from control leaves and the 27-S and 17-S RNA from either treatment. The lowest molecular weight RNA isolated from systemic-induced resistant areas gave positive tests with orcinol reagent and had an absorption spectrum characteristic of a nucleic acid. When treated with pancreatic ribonuclease and mixed with TNV, inhibition no longer occurred.

ISSN:0008-4026    

DOI:10.1139/b69-276

出版商:NRC Research Press    

年代:1969

数据来源: NRC

摘要:

Electron microscopy shows that the nuclei in immature uredospores ofPuccinia graminis triticipossess prominent nucleoli with a mean diameter of 1.7 ± 0.4 μ. The nucleoli in mature uredospores are much smaller (0.5 μ). This reduction in size of the nucleoli may indicate that ribosomal RNA (ribonucleic acid) formation is repressed as uredospores mature.

ISSN:0008-4026    

DOI:10.1139/b69-277

出版商:NRC Research Press    

年代:1969

数据来源: NRC