摘要:

Electronmicroscope studies on fine structure of theARUMspadix. —Three main stages of spadix development have been recognized. In the first stage — during wigh the growth would be embrional and by cell division, while respiration would sharply increase — new mitochondria are continously generated, mainly by the activity of long organules (chondriochontha). The morphology of these mitochondria is quite peculiar, showing bended cristae, often ring — or arc-shaped, and closed. In the second stage — during wich the growth would be by cell enlargment and respiration would further increase — the production of new mitochondria is decreasing, but thed are still numerous in each cell, and show a larger number of cristae (or tubules) than mitochondria observed in the first stage. A generalized vesicle production by the endoplasmic reticulum and the cristae of mitochondria is apparent at the beginning of the third stage — during wich the spadix gradually involves and respiration would fall down. Later, presumably in concurrence with the loss of cell vitality, the membranes of mitochopdria are disrupted, and all the cell structuree less evident. A great interest is presented by the vesicle production; indeed visicle production by the endoplasmic reticulum, and often also by mitochondria, can be observed in the senescent cells, already present and scattered in the tissues of the very young spadices. This ultimate process is howerer often preceded by the re-absorption of the outer membranes of these organules, in connection of the cristae, wich therefore become opened and in communication with the cell cavity.

ISSN:0017-0070    

DOI:10.1080/11263506309430200

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

Some aspects of the variability in wood structure of a specimen ofPRUNUS PERSICA Stokes. —The secondary xylem of a young stem of Prunus persica Stokes has been investigated under three main headings:1)vessel and fibre length;2) intrusive fibre growth;3)relative amount of libriform fibres, fibretracheids and tracheids.

ISSN:0017-0070    

DOI:10.1080/11263506309430201

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

Regeneration and vegetative multiplication inENTEROMORPHA COMPRESSA(L.) Grev. —Fragments of young filaments of Enteromorpha compressa were cultured in order to determine its regenerative and multiplicative power and time limit.

ISSN:0017-0070    

DOI:10.1080/11263506309430202

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

Flower morphogenesis and embriogeny in a bisexualPOPULUS DELTOIDES. —Flower organogeny and embryogeny in a bisexualP. deltoidesis studied. The most interesting stages of its sexual cycle: microsporogenesis, megasporogenesis, evolution of the female gametophyte, fertilization, endosperm and embryo development, are described. From the research appears that the flower is protrandrous and embryogeny is of the normal type as described by Nagaraj (1952) for the dioeciousP. deltoides.It is also pointed out that in the poplar studied the self-fertilization with production of high percentage (more than 65%) of fertile seeds is possible.

ISSN:0017-0070    

DOI:10.1080/11263506309430203

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

Orservation on the morphology and the anatomy on the subterranean organ ofCARLINA ACAULISL. —The morphology and the anatomy of the subterranean organ of Carlina acaulisL.have been studied in relation to the structure of the analogous organ in Atractylis gummifera L. (Maugini, 1960). It has been shown that the two organs differ markedly: in Carlina there is an evident flattening and dissociation of the stem and a dual anatomical structure, related both to stem and to root.

ISSN:0017-0070    

DOI:10.1080/11263506309430204

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

Cause of tumor formation inNICOTIANAhybrids. Further serological studies. —Additional researches have been carried out about genetical tumors in genusNicotiana.By means of serological procedure the affinity among pairs of species that give rise to tumorous and non-tumorous hybrids has been tested, considering also their phyletic interrelation. Using ion exchange chromatography a qualitative analysis of the total proteins of tumorous and non-tumorous tissue of hybrids and of normal leaves taken from hybrids and their parental species was carried out. Serological analysis of affinity between the species tested gave following results:

ISSN:0017-0070    

DOI:10.1080/11263506309430205

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

Action of some respiratory inhibitors on the greening of apices of etiolated pea. —Aim of the research is to study the effect of some of the best kown respiratory inhibitors on the greening of etiolated apices of peas excised from the plant and kept in light in solutions containing saccharose. The inhibitors studied may act on more than one of the reactions leading to the synthesis of the chlorophyll molecule.

ISSN:0017-0070    

DOI:10.1080/11263506309430206

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

ISSN:0017-0070    

DOI:10.1080/11263506309430207

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

ISSN:0017-0070    

DOI:10.1080/11263506309430208

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor

摘要:

The effects of gibberellic acid on the composition ofVICIA FABA. —The A. takes into consideration fresh weight, dry weight, total ash and chlorophyll, carotene, mineral content variations in Vicia Faba L. plants as affected by pure and practical gibberellic acid treatments.

ISSN:0017-0070    

DOI:10.1080/11263506309430209

出版商:Taylor & Francis Group    

年代:1963

数据来源: Taylor