摘要:

B- Chromosomes in the genusURGINEA(liliaceae). —The karyotype of a plant ofUrginea fugaxvar. majorcoming from Morocco has been investigated cytologically and found to be diploid with a chromosome complement of z (zygotic number) = 2n = 20 + 6B's.

ISSN:0017-0070    

DOI:10.1080/11263506409430515

出版商:Taylor & Francis Group    

年代:1964

数据来源: Taylor

摘要:

Cultural techniques for wheat seeds submitted to embryo transplantation. —The author, on the basis of his experience coming from the work carried out on the embryo transplantation for several years, takes in consideration some aspects, at technical level, regarding the best way to cultivate wheat seeds submitted to embryo transplantation operations.

ISSN:0017-0070    

DOI:10.1080/11263506409430516

出版商:Taylor & Francis Group    

年代:1964

数据来源: Taylor

摘要:

Effects of the growth-retarding compounds«CCC» and «AMAB» on the growth and alkaloidal content ofDatura Stramonium L. — Datura StramoniumL. was administered two fortnightly-doses of 200 cc 10-2M solutions of (2-cloroethyl)-trimethylammonium chloride (CCC) or (allyl)-trimethylammonium bromide (AMAB), poured on the soil of every pot. In the treated plants were noted shorter and thicher stems and petioles and leaves larger in size and darker green than in the controls. Yields of leaves in CCC and AMAB-treated plants were not significantly changed while root fresh and dry weights were decreased. The per-cent concentration of total alkaloids in the leaves and roots of both CCC and AMAB-treated plants was not significantly different in comparison with that of normal plants. Therefore the A. assumes that the growth-retarding chemicals must not interfere with alkaloidal synthesis.

ISSN:0017-0070    

DOI:10.1080/11263506409430517

出版商:Taylor & Francis Group    

年代:1964

数据来源: Taylor

摘要:

A comparative study of physiological effects induced by fast neutrons on normal and mealy-endosperm seeds ofTRITICUM DURUM. —Normal and mealy-endosperm seeds ofTriticum durum« Cappelli » were irradiated in the dry state with different doses (700, 1000, 1300 and 1600 rep) of fast neutrons for a study of their radio-sensitivity.

ISSN:0017-0070    

DOI:10.1080/11263506409430518

出版商:Taylor & Francis Group    

年代:1964

数据来源: Taylor

摘要:

Preliminary experiments on the effects of chlorocholine chloride (CCC) and gibberellin A3on vegetative and reproductive development ofCANNABIS SATIVAL. —Applications as soil drench, of 10-5to 10-2M solutions of the growth-retarding chemical CCC (chlorocholine chloride) to plants of hemp « Carmagnola »(Cannabis sativa L.),experimentally cultivated in pots, reduced stem elongation proportionally to the doses employed. In comparison with the control, a marked dwarfing effect, leaves darker green, and a pronounced and early branching were particularly noticeable for plants treated with 10-3and10-2M solutions of CCC. The effects of the chemical were completely nullified when a gibberellin spray of 100 p.p.m. was applied simultaneously or prior to CCC, but only partially when applied after 15 days.

ISSN:0017-0070    

DOI:10.1080/11263506409430519

出版商:Taylor & Francis Group    

年代:1964

数据来源: Taylor

摘要:

Structural changes in plastids of germinating seeds. Observations on the Clementine(CITRUS NOBILISxC. AURANTIUM AMARA PUMILA)cotyledons and the Castor-bean(RICINUS COMMUNIS)endosperm. —The structural changes in the plastids of germinating seeds have been studied with the electron microscope in the cotyledons of the Clementine(Citrus nobilis x C. aurantium amara pumila)and in the endosperm of the Castor-bean(Ricinus communis).In the seeds of the Clementines the chloroplasts are already present in the repening fruit, and contain one or few isolated grana, which are never connected by stroma lamellae. In the endosperm of resting Castor-bean seeds, the plastids, as other cytoplasmic organules, are not easily found, being the cells filled with large and numerous fat bodies or oil vacuoles, crowded and packed together so that some leucoplasts can be found only in the germinating seeds.

ISSN:0017-0070    

DOI:10.1080/11263506409430520

出版商:Taylor & Francis Group    

年代:1964

数据来源: Taylor

摘要:

Morphological organization of the lomasomes. —From a study on morphological organization of the lomasomes, inAvenacoleoptile cells, it has been reported: 1) lomasomes form is quite variable, nevertheless, usually they resemble to a cone having a flattened tip and the base line against the cellular wall. 2) the external border of the lomasoma towards the cytoplasm is represented by the plasma membrane; such external profile results very sinuous and deep invaginations are present. 3) the internal structure is characterized by the presence of an unstructurated matrix containing spherical vescicles, flattened vescicles and tubules all showing an higher density to the electron radiations than the cytoplasmic matrix. Both vescicles and tubules are delimited by a single membrane.

ISSN:0017-0070    

DOI:10.1080/11263506409430521

出版商:Taylor & Francis Group    

年代:1964

数据来源: Taylor

摘要:

Electron microscope studies on root nodules of some leguminous plants. —From this study of ultrathin sections of root nodules of Pea, Bean and Kidney-bean plants, it has been possible to recognize the infrastructural changes which occur during the development of the root nodules, both in the special cells (containing Rhizobia) and in the intermediary cells (free of Rhizobia). With regard to the symbiotic bacteria it has been possible to ascertain that their penetration into root nodules occurs by means of an infection's thread (delimited by its own wall), which contains numerous Rhizobia dipped in an abundant mucilage, with which they, at the beginning, are released into the host plant's cells. The Rhizobia appear enveloped by three membranes, namely a thin citoplasmic membrane, a cell wall, and a « membrane envelope », this last looking at the beginning rather detached from bacterial cell, by the presence of mucillaginous substances which afterward become less and less reduced. The membrane envelope, which is common for several bacteria in the kidney-bean plants, surrounds instead a single bacterium in the pea and in the bean plants. The importance of this membrane seems to rely on the fact that, according to some Authors, it would be formed around the bactetia which are active in nitrogen fixation. Moreover, it has been possible to find out that, among the varous Leguminous plants studied, there are remarkable differences in the morphology of the bacteria as well as in their modifications during the evolution to bacteroid stage.

ISSN:0017-0070    

DOI:10.1080/11263506409430522

出版商:Taylor & Francis Group    

年代:1964

数据来源: Taylor

摘要:

ARTEMISIA CAERULESCENSL. varCRETACEAFiori: its morphology, anatomy and santonin content. — Artemisia caerulescens L.var. cretaceaFiori, endemic of the loamy soils of Romagna and Tuscany, has been collected near Siena and specimens have been submitted to morphological, anatomical, systematic researchs.

ISSN:0017-0070    

DOI:10.1080/11263506409430523

出版商:Taylor & Francis Group    

年代:1964

数据来源: Taylor

摘要:

Researches on ultrastructure of Avena coleoptile. 3. The sieve elements. —A study on the ultrastructural organization of the mature sieve elements ofAvenacoleoptile has been carried out. Data suggest that functional phloem tubes are alive and remain alive until they are working. Judging on morphological basis, the metabolic activity of sieve elements should be of peculiar type and low in comparison to that of the companion cells. In fact the cytoplasm is located in a narrow parietal strand, mitochondria, Golgi apparatus and endoplasmic reticulum are present, but they appear very modified; plastids and nucleus are absent. The cytoplasm is bounded externally by a normal plasmalemma, whilst the vacuole has no visible limits: a tonoplast is, therefore not identifiable.

ISSN:0017-0070    

DOI:10.1080/11263506409430524

出版商:Taylor & Francis Group    

年代:1964

数据来源: Taylor