摘要:

Heterothallism in three physiological races ofDidymium iridiscollected from Honduras (Mexico), Hawaii, and Australia are reported. Pure clone matings of these races are found to be governed by multiple alleles of incompatibility factors, heterozygosity of which leads to zygote formation. Two of these races behave identically in their mating reactions although their plasmodia are non-fusable. Existence of a two-locus system with linkage of parental alleles is suggested to explain the mating behavior of the pure clones handled and the absence of tetrapolarity. Because of aging and artificial culture, intraracial sterility develops in the pure clones. These clones retain their interracial fertility. Sporadic Plasmodia occasionally form in some of the pure clones probably because of a localized mutation. Zygote formation with the mutated cell apparently leaves the remaining clone population uncontaminated.

ISSN:0008-4026    

DOI:10.1139/b64-141

出版商:NRC Research Press    

年代:1964

数据来源: NRC

摘要:

Stages in the development of pycnidia and pycnospore discharge ofPlenodomus meliloliDearness and Sanford are presented. Liquid droplets, which exude from pycnidia prior to pycnospore discharge, contained 17 amino compounds. Reducing sugars or sucrose were not detected.

ISSN:0008-4026    

DOI:10.1139/b64-142

出版商:NRC Research Press    

年代:1964

数据来源: NRC

摘要:

The method of Smillie and Krotkov has been applied to the estimation of soluble ribonucleic acid and deoxyribonucleic acid in nine species of marine algae, representative of the Chlorophyceae, Rhodophyceae, and Phaeophyceae. Treatment of the extract with an anion exchange resin was essential for the determination of RNA. Values for RNA and DNA, expressed as percentages of total solids, were respectively as follows:Ulva lactuca0.63 and 0.10,Chondrus crispus0.91 and 0.65,Rhodymenia palmata0.73 and 0.41,Porphyra umbilicalis1.62 and 0.19,Furcellaria fastigiata0.37 and 0.36,Laminaria longicruris0.68 and 0.06, L.digitata0.67 and 0.30,L. agardhii0.90 and 0.07,Fucus vesiculosus0.29 and 0.05, based on commercial nucleic acids assayed by ultraviolet absorption, as standards. Use of ribose and deoxyribose as standards gave lower results. Attempts to prepare pure polynucleotides from several marine algae were unsuccessful.

ISSN:0008-4026    

DOI:10.1139/b64-143

出版商:NRC Research Press    

年代:1964

数据来源: NRC

摘要:

A new method for determination of the location of alkaloids in plant tissue is described. The method utilizes freeze-dried tissue and an iodine-based staining procedure. WithLupinus luteustissue, the amounts of alkaloids were found to be highest in areas of greatest chloroplast concentrations.

ISSN:0008-4026    

DOI:10.1139/b64-144

出版商:NRC Research Press    

年代:1964

数据来源: NRC

摘要:

Fusariella hughesiisp. n. is described and illustrated. The fungus was isolated from the dispersal units ofPhalaris minorRetz. andTrigonella arabicaDel.

ISSN:0008-4026    

DOI:10.1139/b64-145

出版商:NRC Research Press    

年代:1964

数据来源: NRC

摘要:

The isolation ofHypoxylon pruinalum(Klotzsche) Cke. from discolored wood beyond visible canker limits provided the first indication that this fungus invades xylem under sound bark ofPopulus tremuloidesMichx. The strong inhibition of the fungus growth on bark meal agar and the active growth on wood meal agar is another demonstration of this particular host and parasite interaction. Further evidence for this behavior was obtained experimentally with living bark and wood of aspen. These studies have also shown that the fungus produces diffusible substances toxic to the living host tissues. It is concluded thatH. pruinatumis a sapwood parasite.

ISSN:0008-4026    

DOI:10.1139/b64-146

出版商:NRC Research Press    

年代:1964

数据来源: NRC

摘要:

A branch and stem canker disease, affecting up to 40% of exotic larch trees in plantations and a number of native larch trees in natural stands, was investigated in Quebec. The disease was found to be associated with the imperfect stage ofLeucostoma kunzei(Fr.) Munk ex Kern. The taxonomic position of this fungus is reviewed.Monoascosporic isolates obtained from different sources yielded various cultural patterns but these could not be related to hosts or to ascospore size. Isolates from exotic larches developed less rapidly than those from native larch on various media.Results of field inoculations indicated that exotic larches are more susceptible than the native species. Susceptibility of a number of other coniferous species was also demonstrated. Unfavorable environmental factors, such as persistent summer drought, seemed necessary for the establishment and development of the disease.

ISSN:0008-4026    

DOI:10.1139/b64-147

出版商:NRC Research Press    

年代:1964

数据来源: NRC

摘要:

The fine structure of uredospores and germ tubes ofPuccinia graminisf. sp.triliciis described from electron micrographs of cells fixed in KMnO4. In terms of their principal cytoplasmic structures (nuclei, mitochondria, endoplasmic reticulum, and protoplasmic and vacuolar membranes) these cells bear a general resemblance to other fungi and higher plants but differences between resting cells and germ tubes were noted in the size of oil bodies and the structure and extent of the endoplasmic reticulum.

ISSN:0008-4026    

DOI:10.1139/b64-148

出版商:NRC Research Press    

年代:1964

数据来源: NRC

摘要:

Chromosome numbers are given for 69 collections of 24 species of Cruciferae in the generaAlyssum, Arabidopsis, Arabis, Barbarea, Cakile, Eutrema, Hali-molobos, Nasturtium, Rorippa, Thellungiella, and Turritis. The following chromosome numbers are reported for the first time:Alyssum desertorum, n = 16;Arabis canadensis, 2n = 14;A. divaricarpa, 2n = 13 + 2B, 14, 20 + 2B, 21, 28;A. drummondii, 2n = 20;A. holboellii, 2n = 13 + 2B, 20 + 2B;A. lemmonii, 2n = 14;A. lyallii, 2n = 21;A. lyrata, 2n = 32;A. pendulocarpa, 2n = 14;Barbarea orthoceras, 2n = 16;Cakile edentula, 2n = 18;Rorippa curvisiliqua, 2n = 16;Thellungiella salsuginea, 2n = 14. It is concluded that species ofArabisnative to North America and western Greenland have the base numberx = 7 and many of them are apomictic whereas Eurasiatic species of this genus have anx = 8 base number and are sexual.

ISSN:0008-4026    

DOI:10.1139/b64-149

出版商:NRC Research Press    

年代:1964

数据来源: NRC

摘要:

A spergillus striatusspec, nov., a new member of theA. nidulansgroup, has been described from Mangrove mud, collected from Kagh Islands, West Bengal, India. It is distinct from all the hitherto known ascosporic aspergilli in having large, lenticular, purple-red, and striate ascospores, devoid of equatorial crests.

ISSN:0008-4026    

DOI:10.1139/b64-150

出版商:NRC Research Press    

年代:1964

数据来源: NRC