摘要:

SUMMARYSeveral species of tube‐dwelling, pennate diatoms present in salt marshes adjoining Sapelo Island, Georgia, possessed previously undescribed types of motility. The tubes penetrated into the sediment, permitting the diatoms to retreat from the sediment surface in response to stimuli. Cells ofNitzschia ob‐tusawithdrew down their lubes at 120 to 240 ^jsec. Colonies ofFrustulia asymmetricawithdrew at 44 to 500 μ/sec, with the cells remaining motionless relative to the tube. Tubes containing colonies ofGyro‐sigma scalproidesvar.eximiaand aNaviculasp. moved slowly into or out of the se

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1965.tb04573.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

SUMMARYNitellopsis bulbillifera,known previously only from the type locality in Argentina, is reported from near Roswell, New Mexico. Specimens from the natural population and from culture show only minor variations in respect to the description of the type specimen. A description of male plants and chromosome counts are presented for the first time. Similarities betweenN. bulbilliferaandChara buckelliiare discussed.

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1965.tb04574.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

SUMMARYWith growth rate as the criterion, the responses of several species and strains ofChlorellato boron were investigated. The algae wereChlorella vannieliiShihira and Krauss, C. emersoniiShihira and Krauss, C. protothecoidesvar.mannophilaShihira and Krauss, andC. vulgarisBeijerinck, Columbia strain.There was no evidence of a boron requirement for any of the four strains of algae. In contrast with most higher plants, for which a few parts of boron per million are usually toxic, 50 to 100 ppm of B, depending on the alga, toxic required for a statistically significant (5% level) reduction in growth rate.

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1965.tb04575.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

SUMMARYA new variety ofCaulerpa filicoidesfrom the Andaman Sea is described.

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1965.tb04576.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

SUMMARYA good relationship was found between the amount of phosphatase present at the surface of marine unicellular algae and their ability to utilize glucose‐6‐phosphate (G‐6‐P) as a phosphorus source. Algae did not take up the whole molecule of G‐6‐P; those with phosphatase hydrolyzed the ester extracellularly and assimilated the PO4. The phosphatases were usually phosphate‐repressible, and they usually showed optimum activity at pH±7. Algae lacking phosphatases that could act on external substrates did not assimilate G‐6‐P; they became phosphorus‐deficient and stopped growing. Of 13 species studied, onlyCyclo‐tella crypticawas capable of assimilating glucose for cell growth in darkness.Cyclotellautilized both the glucose and the phosphate of G‐6‐P, but only after hydrolysis by the alkaline phosp

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1965.tb04577.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

SUMMARYThe enormous quantity of work done in the Soviet Union is inadequately known elsewhere. Soviet generalizations rest on extensive data published in the Russian and Ukranian languages. The primary criterion of community analysis is now the total algal flora, but it is foreseen that the ecology of individual species is a more desirable parameter. Methods of sampling and culture in the Soviet Union are largely the same as those used elsewhere. The basic problems of sampling and quantification have not been solved yet.It is felt that the prerequisite to understanding the Soviet experience is a commonly held taxonomy. Soviet taxonomists are judged as fully competent, but lack communications with outside taxonomists in respect to methodology and references. As a contribution to the common understanding, new identifications of Soviet species (mostly blue‐greens) are included in this paper. These were derived from: a study of moist soil dishes from collections made according to a horizontal distribution plan in a single field; collections from near Leningrad, Middle Asia (Alma‐Ata, Tashkent, Samarkand, Buchara); liquid cultures of soil collected by a Soviet investigator in Kazakistan; and agar cultures of soil algae which are maintained in Soviet laboratories. Also included is a selected bibliography, in English translation, of 71 Soviet publicati

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1965.tb04578.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

SUMMARYThe enucleate, mature sieve elements ofMacrocystispossess thick cell walls composed of microfibrils of cellulosic substance impregnated with amorphous substance(s). Sieve plates are also basically microfibrillar with callose deposits. Protoplasmic connections between the sieve tubes and other cells have not been observed.Freshly cut and fixed sieve tubes reveal a peripheral layer of plastids, vesicles, and endoplasmic reticulum surrounding a large lumen filled with fine granular to fibrillar material interrupted by large masses of electron dense, aggregated slime. Sieve plates with masses of slime and callose constricting pores are numerous.Liquid nitrogen‐frozen, osmium‐fixed sieve tubes contain a peripheral layer of plastids, numerous vesicles of many sizes, numerous mitochondria with well‐developed cristae, occasional dictyosomes, and endoplasmic reticulum. Masses of slime are absent. The mature sieve tube lumen contains dispersed slime which is continuous through the unobstructed pores of sieve plates.These fine structural studies indicate many similarities between the sieve tubes ofMacrocystisand those of vascular plants. However, the large number of well‐preserved organelles in the peripheral layer ofMacrocystissieve elements, constitute a striking difference from most vascular plant sieve tubes so far examined, and may indicate a greater degree of metabolic independence byMacrocystissieve tubes which lack companio

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1965.tb04579.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

SUMMARYInhibition of growth of single cells ofAnacystis nidulanson the surface of or in plates was due to H2O2. This H2O2arises from reaction of citrate and Mn2+in a defined medium, C, by heat (autoclaving) or light (especially 365 mμ). The simplest way to avoid H2O2formation was to lower or omit Mn2+from the medium. Thus medium C minus Mn2+routinely gave excellent quantitative growth of single cells ofAnacystisunder simple incubation conditions. The H2O2sensitivity ofAnacystiswas unexpectedly high; ≈ 50 μg/liter inhibited single cells on the surface of agar plates. However, other blue‐greens tested had not this exaggerated sensitivity. Seawater contained small quantities of apparently free H2O2. H2O2in seawater perhaps may have an ecological

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1965.tb04580.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

SUMMARYChlorosarcinopsis negevensisn. sp. f.negevensisandChi. negevensisf. ferruginean. f. have been isolated in culture from a desert locality in the Negev. The organisms form regular 3‐dimensional cell packets. Pseudofilamentous groups or a gelatinous matrix are absent. Reserve material is an orange‐colored oil formed in quantities. In old cultures, palmelloid stages appear.Reproduction is by zoospores, autospores, and isogametes. The sensitivity pattern ofChi. negevensisto inhibitory agents differs from that of the other species of the ge

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1965.tb04581.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1965.tb04582.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY