摘要:

SUMMARYProtoplasts that remained metabolically active for several days were obtained by treating cells ofMicrocystis aeruginosa, Anacystis nidulans,andAnabaena flos‐aquaewith lysozyme. Photosynthetic and respiratory rates were near those of control cells. Lysozymeresistant cells were isolated which may be genetic mutant

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1969.tb02567.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

SUMMARYThe development of spores and eggs of Zonaria farlowii was studied with light and electron microscopy. Oogonia require a lunar month to develop and are produced in periodic crops. The sporangia, on the other hand, are longer in developing and on a particular plant do not become mature all at the same time. Differences in size, content, and products of sporangia and oogonia have been found. One of the quantifiable differences is in the amount of osmiophilic substance, presumably oil, present in the 2 cells. This substance is more abundant in the sporangium, a cell which produces 8 reproductive spores. These differences are particularly interesting since the embryology of sporic and zygotic germlings has been found to be identical, while ontogeny of spores and eggs differs. The findings of this study are discussed in view of possible relationships between microstrtrclitral features of spores and fertilized eggs and their subsequent development.

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1969.tb02568.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

SUMMARYThe life histories of the red algaeRhodochorton purpureumandR. tenuewere studied in unialgal culture. Telrasporophytes produced sporangia in short day regimes (8–12 hr) with 50–200 ft‐c cool white light at 10 or 15 C. Mature gametophytes were not observed in the Washington and Alaska clones ofR. purpureum.Tetraspores fromR. tenueand the California clones ofR. purpureumgive rise to unisexual gametophytes that are reproductive when smaller than the tetrasporophytes. The tetrasporophytes develop directly from the gonimoblast cells. Because of similarities in morphology and life histories, it is proposed thatR. tenuebe placed in synonomy withR. purp

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1969.tb02569.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

SUMMARYThe tubular sheath ofAmphipleura rutilans iscomposed of small fibrils 20–25 A in diameter. The endotubular environment is further partitioned by individual cell sheath formation. The tube boundary seems to be an effective barrier against damage from extreme salinity changes, but does not prevent passage of EDTA, neutral red, surfactants, or caffeine. Terminal swellings develop on growing tips during extremely cold periods. These give rise to 2 or more separate growing tips which proceed to form regular tubes. There was no evidence for sexual reproduction or auxospore formation within the terminal swellings, even though adjacent swellings fused. Bacterial, algal, and fungal epiphytes were abundant on the extratubular surface. Hollow lipid bodies occurred in many cells. A rimring strand of presumed DNA occurs in the chloroplast. It is proposed that the tube material serves not only as a protective boundary but also functions as an active nutrient tra

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1969.tb02570.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

SUMMARYThe fatty acid spectra of 6 periphyton communities developed in laboratory streams at different combinations of light intensity and current velocity were determined by gas‐liquid chromatography and silver nitrate thin‐layer chromatography. Differences in species composition of the communities apparently had no striking effect on proportions of palmitic and stearic acids, whereas concentrations of myristic, palmitoleic, oleic, linoleic, and linolenic acids and a C20:5acid were more closely related to taxonomic differences. In general, communities dominated by blue‐green algae exhibited relatively high proportions of oleic, linolenic, and linolenic acids and low proportions of palmitoleic acid and a C20:5acid, as compared to communities consisting primarily of diatoms. The data also indicated an inverse relationship between fatty acid redundancy and species dive

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1969.tb02571.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

SUMMARYThick‐walled, oil‐filled akinetes of the green algaSpongiochloris typica,long in the stationary phase of growth, were transferred to fresh media. Ultra‐structural changes were observed during a 51‐hr period after transfer. Akinetes, when transferred to fresh media, may follow 1 of 3 pathways:1Remain unchanged; these cells appear to be moribund perhaps due to an over‐accumulation of lipid.2Undergo immediate zoosporogenesis; seems to occur in cells with 4, 8, or more nuclei.3Return to the vegetative state; this was common in smaller cells with less than 4 nuclei; however, zoosporogenesis eventually did occur when 4, 8, or more nuclei wer

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1969.tb02572.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

SUMMARYAn unidentified species of the diatom genusCocconeishas been isolated from the sediments of Biscayne Bay, Florida. The organism is capable of utilizing a range of organic substrates, including lactate, in the light but not in the dark, as shown by growth studies. Information is included on changes in cell carbon, nitrogen, and chlorophyll a during growth in batch culture. Data obtained on the kinetics of uptake of lactate and glucose raise questions on the possible ecological significance of photoheterotrophy among marine microalgae, particularly those in estuaries.

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1969.tb02573.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

SUMMARYTheConchocelisphases ofPorphyra perforataf. patens, P. cuneiformisandP. nereocystiswere cultured from spores in a sterile artificial medium at 12 C and with 25 ft‐c illumination for 10 hr daily. The cultures showed differences in duration of the vegetative phase, sporulation, liberation of spores, and the return to the leafy phase. Morphological differences were also noticed. Since the 3 species were grown under identical conditions, it is inferred that these characteristics are probably different for the 3 species studie

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1969.tb02574.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

SUMMARYThe variability exhibited byDraparnaldiaboth in nature and in the laboratory makes it difficult to identify the species. The natural variability ofDraparnaldiawas amplified by the environmental conditions and the media used in this study.With the hope that chromosome studies would aid in taxonomic characterization by providing additional differentiating criteria, special attention was devoted to adapting techniques which could be used to determine chromosome numbers ofDraparnaldiaisolates. The chromosome numbers reported herein are as follows: (1)Draparnaldia glomerata,Isolate #1, isolated from Davis Falls, Montevallo, Alabama, was found to have a chromosome number of 13. (2)DraparnaldiaIsolate #2, an unidentified species obtained from Anniston, Alabama, was found to have a chromosome number of 13. (3)Draparnaldia acuta,Isolate #3 from Northwood Lake, Northport, Alabama, exhibited 26 chromosomes. (4)Draparnaldia plumosastrain 423 (Indiana Culture Collection), 418/a (Cambridge) was observed to have a chromosome number of 13.

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1969.tb02575.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

SUMMARYThree strains were isolated from Bermuda waters as unialgal cultures. Although identical in cell shape, cell size, and general growth features, marked differences in pigmentation, filament length, and sheath thickness were noted. These differences are explained as being due to differences in physical conditions of the areas of isolation of the 3 strains. It is concluded that the 3 strains are ecologically selected mutants of the single species, Schizothrix calcicola.

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1969.tb02576.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY