摘要:

Researches about the cycle of the phytoplankton in the lake of Piediluco (Umbria). — The Authors studied the phytoplanktonic productivity within an year (1960–1961) in the lake of Piediluco (Central Italy); they have tried also to bring into evidence eventual changes in the phytocoenosis of the lake, basing themselves on some phytoplanktonic analysis made byPasquini(1924) and byMarchesoni(1940) on samples collected before that Nera River was put in the lake for hydroelectric purpose.

ISSN:0017-0070    

DOI:10.1080/11263506309434944

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

Researches on the water content and osmotic pressure in plants of three forest associations in the Marche. I° -The water content. — The main forest associations of the Umbro-Marchigiani Appennines are the Orneto-Quercetum ilicis, theQuercetum pubescentis (s. l.)and theFagetum. In each of these associations a typical station has been chosen where the most important species have been followed from March to November 1963 in order to determine the seasonal variations of their water content(« T.I. »)expressed as percentage of fresh weight.

ISSN:0017-0070    

DOI:10.1080/11263506309434945

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

Inhibitors in the sarcotesta ofGINKGO BILOBAseeds and their retarding action on embryo growth. — The sarcotesta ofGinkgo bilobaseeds contains some inhibitors which delay or hamper the germination of other cormophytes seeds. This has been proved with seeds ofHordeum vulgareL.,Vicia sativaL., andTriticum vulgareL. germinating in water extracts of ripe sarcotesta at various concentrations.

ISSN:0017-0070    

DOI:10.1080/11263506309434946

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

The effect of auxin on the metabolism of14C labelled glycerol in isolated pea internode segments. — The effect of auxin on the respiratory metabolism of isolated pea internode segments was investigated by measuring the auxin-induced modifications of glycerol-1-14C incorporation in some metabolites.

ISSN:0017-0070    

DOI:10.1080/11263506309434947

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

Preliminary observations on the submicroscopic structure of the endospermic starch granules inTRITICUM DURUMdesf. (The electronic transparency of the starch granules). — The starch granules ofTriticum durumDesf. kernels have been examined by electron microscopy.

ISSN:0017-0070    

DOI:10.1080/11263506309434948

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

On the functional activation of germinanting seeds. Note V. Alcohol dehydrogenase activity. — The activity of alcohol dehydrogenase is determined by spettrophotometric method on acetone precipitates of dry and germinating seeds of leguminous and graminaceous plants.

ISSN:0017-0070    

DOI:10.1080/11263506309434949

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

Observations on the infrastructures of ANABAENA CYCADINAE and of root-nodules cells ofCYCAS REVOLUTA. — Light and electron microscope observations carried on the fine and ultrafine sections of root-nodules ofCycas revoluta, brought in evidence differences structural and infrastructural of cells. These differences concern mainly the modifications presented by reticulum endoplasmic which in middle-aged cells takes a fragmentary and vescicular aspect, and the mitochondria which, in the same cells, show short cristae starting by outside wall of the organul.

ISSN:0017-0070    

DOI:10.1080/11263506309434950

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

On the natural bleaching of hyacynth(HYACINTHUS ORIENTALIS)tepals, green in earlier stages, and on the unreversibility of chloroplasts. — The theory ofSchimper (1885), according which the types of plastids are interchangeable, and which some authors(Frey-Wyssling, Ruch and Berger 1955; Frey-Wyssling, 1961)rejected on the ground of the new views on the submicroscopic cell morphology, has not yet received, from the electron microscope, neither evidence, nor criticism. One of the most discussed points, and for which we still need further observations, is represented by the interchangeability of the chromatophores (chloroplasts and chromoplasts) into leucoplasts. The few observations reported, indeed, dealt with genetical situations(Robbelen, 1959)or abnormal and pathological states(Gerola et al., 1960, 1962); and their conclusions might therefore receive some criticism which — from the view of the problem here studied — invalidates their real value. In this paper, the author follows, with the electron microscope, the chloroplast involution in the tepals ofHyacynthus, which are green before the anthesis, but bleach when blossom. Chloroplast structures are described, and their progressive changes reported. The writer can conclude that, at least in the material used, the chloroplasts cannot change into leucoplasts, but gradually involve, always keeping, until the latest stages, their characters of green plastids. Some observations are also reported, on the different structure of the stroma lamellae and of the grana lamellae, on the ground of their different behaviour during plastids involution.

ISSN:0017-0070    

DOI:10.1080/11263506309434951

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

« Lomasomes »: their probable role in the expansion growth of the cell wall. — It was previously reported that lomasomes are present in higher plant cells. In a preliminary comunication Authors described the morfological characteristics of the lomasomes and their position in the cell. It was shown that lomasomes vary in organization which appears to be granular or vescicular and in distribution along the cell wall. Both these characters seemed directly related with the level of cellular differentiation.

ISSN:0017-0070    

DOI:10.1080/11263506309434952

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

Embryological researches onSENECIO VULGARISL. var.THYRRENUSFiori. — Male gametophyte, development of tapetal cells and female gametophyte have been studied inSenecio vulgarisL. varthyrrenusFiori.

ISSN:0017-0070    

DOI:10.1080/11263506309434953

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor