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1.
Abstract

SOME INVESTIGATIONS ON THE BEHAVIOUR OF EXCISED EMBRYOS OF TRITICUM DURUM CV. « CAPPELLI », COMING FROM NORMAL GRAINS AND YELLOW BERRIES. — Excised embryos of Triticum durum cv. « Cappelli », coming from normal grains and yellow berries, soaking in distilled water for 24 hours, were brought up for 6 days in petri dishes, on a 1% solution of agar + glucose, at the constant temperature of 23°C, at the light of a common germicidal lamp. As controls, normal grains and yellow berries were utilized, placed in petri dishes each containing a piece of filter paper moistened with distilled water. After 6 days, the seedlings (measured the shoot and the longest root) were transferred to a greenhouse in sand, at daylight (average temperature: 16°-18°G.). After 14 days, the shoot and the longest root of each seedling coming from the sand cultures were measured.

The following results were obtained:
  1. control seedlings: after 7 (1 + 6) days, the normal seedlings grow more than those coming from yellow berries and the shoots grow as the roots (see MELETTI e ONNIS 1961 a, b e c); after 21 days, the situation of the control seedlings is again completely regular (normal shoots are longer);

  2. seedlings coming from excised embryos: differences of growth are not here, neither after 7 nor after 21 days, among seedlings coming from normal grains and yellow berries.

These data should allow to conclude that the embryos, coming from normal grains and yellow berries, grow in the same way. But the limits of the utilized technique (want of balance in the relations between shoot and root, low survival of the seedlings coming from the excised em bryos, which grow too little in respect of the controls) suggest to carry into other investigations on the same subject.  相似文献   

2.
3.
Abstract

Inactivation and riactivation of enzymes in endosperms of castor bean seeds. — On the basis of previous results, the possibility has been investigated of the reversible interconversion of active and inactive form of enzymes in castor bean seeds, during their development.

The results described here indicate that:

  1. the activity of some glycolytic enzymes increases greatly (81% and 400% increase of, respectively, Gl-6-P-dehydrogenase and aldolase) upon incubation of dry seeds for few hours at 4 °C.

  2. The decrease of enzyme activity upon dehydration of seeds and the increase during the subsequent imbibition can be shown reproducibly.

  3. This same observation is made for oxygen uptake.

These results are interpreted to indicate the reversible inactivation of enzymes caused by dehydration of seeds.  相似文献   

4.
Abstract

Effects induced by the exchange of embryos between normal grains and yellow-berries of « Cappelli » (Triticum durum Desf.). — Normal grains of « Cappelli » give seedlings, the shoots of which are longer than those coming from yellow-berries (Meletti e Onnis, 1961, a). The exchange of embryos between the two grain types shows the influence of endosperm on the seedling growth: the normal endosperm stimulates, while the yellow-berries endosperm depresses. The causes of this phenomenon are to research probably within the limits of the relationship, at biochemical level, between embryo end endosperm, with special regard to a likely different hormonic situation in normal grains and yellow-berries.  相似文献   

5.
Abstract

The effect of sugars on growth of isolated cotyledons from germinating castor bean seeds. — The presence of sugars in the medium induces a number of biochemical and physiological changes in the cotyledons isolated from germinating castor bean seeds. In the present research, the extent and the mechanism of the effect of sugars on growth of the isolated cotyledons was investigated.

The results achieved may be summarized as follows:

  • Sucrose markedly stimulates the growth (as increase of fresh weight) of the isolated cotyledons; its action is already apparent when using a 10-2M concentration and reaches a maximum (stimulation by about 400%) for the concentration between 5.10-2M and 1,5.10-3M. The increase of sucrose induced growth is due in almost equal proportions to water uptake and to increase of dry weight.

  • The difference (Δ P.O.) between the osmotic pressure (P.O.) of the cell sap and that of the external medium is markedly higher for the cotyledons treated with sucrose (7–8 atm.) than the Δ P.O. of cotyledons incubated in water.

  • Analyses of cell contents in sugars show that sucrose is taken up by the cotyledon cells against a concentration gradient. The increase of the difference of osmotic pressure between cotyledon and the external medium is satisfactorily accounted for by this active accumulation of sugars.

  • When mannitol is added to the incubating medium in addition to sucrose, the active uptake of sugar is not disturbed; but the effect of sucrose on growth decreases, and it completly disappears when mannitol concentration in the medium is such, to make the value of Δ P.O. for the cotyledons in sucrose plus mannitol equal to the Δ P.O. for the cotyledons incubated in water.

  • Besides increasing the P.O. in the cotyledons, sucrose markedly accelerates the decrease of free aminoacid in the isolated cotyledons.

  • Auxin (β—indolacetic acid) does not stimulate, or stimulates weakly, growth of the cotyledon incubated in water; some stimulation can be observed only when sucrose is present. Gibberellic acid stimulates growth (though to a much lower extent than sucrose) in the cotyledons in water, while its action does no longer appear when sugar is present.

The decrease of free aminoacid together with other observations, indicates an effect of sucrose on protein metabolism; however, growth stimulation by sucrose seems to depend essentially on its active accumulation - against a concentration gradient - and thuson the increase of osmotic pressure. It is thus suggested that in these tissues osmotic pressure is the most important factor in limiting growth by cell extension.  相似文献   

6.
Abstract

GROWTH OF PERICARP, SEED, ENDOSPERM, AND EMBRYO IN PRUNUS AMYGDALUS STOKES. — The fruits of an almond-tree growing at Bari were collected weekly from February 22nd to July 11th and on August 16th 1960. The material was kept in fixative; the growth of the various organs was studied both from a morphological and a quantitative point of view. Special attention was given to growth of the endosperm, especially during the nuclear stage and at the beginning of cellularisation (Figg. 1-14), and to the developement of the embryo until it reaches the « heart-shaped » stage (Figg. 15–22). From a quantitative point of view, the volume and main diameters of pericarp and seed, and whenever possible endosperm and embryo, were measured for each fruit. Most of the data are given in Tables I to V and Figg. 23 and 24.

If reference is made to the 3 phases of fruit growth established for other species (notably peaches and cherries), the main conclusions are that:
  1. phase I (growth of pericarp, testa and nucellus) is clearly recognisable; it ends after the micropylar portion of the endosperm has become cellular and the embryo heart shaped;

  2. phase II is also present: during this phase most of the growth of endosperm and embryo takes place; while the seed has reached its definite size at the end of phase I, the pericarp undergoes a period of greatly reduced growth;

  3. two weeks after the beginning of phase II the pericarp seems to resume growth just for a very short period, judging at least by the weekly values of the ratio pericarp volume to seed volume (see Fig. 23); this seems to indicate the existence of a new phase, that is phase III, which in fleshy fruits of the genus Prunus corresponds to a much longer and important process of pericarp growth than in the almond;

  4. as in the peaches and cherries therefore a crisis in pericarp growth occurs during the period of maximum rate of growth of the cellular endosperm and embryo;

  5. the sequence: cellularisation of the endosperm, growth of endosperm and embryo, ceasing of seed growth, and reduction in pericarp growth is very clear, particularly if we take into account growth in length rather than in volume; both morphological and quantitative data would indicate the importance of the endosperm not only for the beginning of embryo development, but also for the control of pericarp growth.

  相似文献   

7.
Abstract

OBSERVATIONS ON THE CARYOLOGY OF GENNARIA DIPHYLLA (LINK) PARL. (COELOGLOSSUM DIPHYLLUM FIORI) — Some caryological characters of Gennaria diphylla (Link) Parl, have been here investigated. Chromosome counts from somatic metaphases show a 34 chromosomes diploid set; the resting nuclei have been classified as half-reticulated with chromocenters (« noyaux semi-reticulé à chromocentres » according to Delay's classification); in prophases we have noticed that chromocenters often appear like prochromosomes. The chromosome number 17 (2n = 34) is new for the Ophrydinae.

The interest of this research lies in the fact that the species here dealt with has been differently classified by various Authors.  相似文献   

8.
Abstract

A comparative study of physiological effects induced by fast neutrons on normal and mealy-endosperm seeds of TRITICUM DURUM. — Normal and mealy-endosperm seeds of Triticum 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.

Analysis of growth in sand and field survival shown that the normal seeds are more sensitive than those with mealy-endosperm: this is shown by a greater growth reduction at 14 and 21 days after sowing and a lower survival, especially with the dose 700 rep.  相似文献   

9.
10.
Abstract

OBSERVATIONS ON A SPECIAL CASE OF WOUND HEALING IN AN OLIVE TREE DAMAGED BY LOW TEMPERATURE IN FEBRUARY 1956. — The authors have observed an unusual form of woung healing in an olive tree damaged by low temperature in 1956, and have studied its morphological and anatomical details.

Attention is drawn to the notable ability of olives to recover from low temperature damage, especially through the activity of the subsidiary trunks « corde » characteristic of the olive tree.  相似文献   

11.
Abstract

Consequences and significance of dormancy Prolongation in «Triticum durum» Desf. — Different environment conditions have effect on the dormancy duration: this has been ascertained also for durum wheat Cappelli. Starting from this acquisition, the author does the embryo exchange between seeds of Cappelli different for dormancy degree. It is demonstrated that there is a direct relation between dormancy degree and inhibition power of endosperm.  相似文献   

12.
Abstract

«Buddleya davidii» in «Valtellina» (North Italy), its settling and diffusion. — Vegetational areas where «Buddleya davidii» is naturalised in Valtellina are described and the subsequent phases are followed through 18 years.  相似文献   

13.
Riassunto

L'A. ha studiato l'embriogia della Vinea difformis Pourr. ed ha potuto stabilire che:

  1. l'archisporio è pluricellulare e possono svilupparis talvolta pi[ugrave] cellule madri;

  2. normalmente solo una cellula madre arriva a maturità;

  3. delle quattro megaspore solo una è fertile e precisamente la pi[ugrave] calazale;

  4. lo sviluppo del gametofito è del tipo Normale cioè Monomegasporiale con oangio emisporiale.

Ha inoltre risontrato una anomalia di sviluppo constituita da un gametofito binucleato abnorme per ritardo delle divisioni nucleari cispetto all'acerescimento che è quello di un gametofito ottonucleato.  相似文献   

14.
Summary

The Author studies the action of the presence of the ear and its parts in the growth of the stem and in the value of the water of traspiration and of assimilation in the higher leaf. The stet shows:

  1. A removed ear, not yet mature, exerts a depressing effect upon the development of the stem and ucon the leaf's functions.

  2. The threads and the pistils removed inhibit the enlongament of the stem and alter the functions of leaves.

  3. Maturing seeds removed cause trubles on the function of the vegetative organ.

This phenomen is due to the presence of an hormonical substances elaborated in the riproduction's orgas, which are considerated the centre of functional correlation.  相似文献   

15.
Abstract

The Influence of Short Periods of Lighting with Different Wavelengths on the Orcadian Changes of the Enzymatic Digestive Activities in Palaemon serratus (Crustacea, Natantia)

The effect of light on the circadian rhythms of digestive activities in the Shrimp Palaemon serratus have been studied.

  1. Continuous darkness leads in a few days to a disappearance of the variations of the circadian rhythms of digestive enzymes while these rhythms go on in continuous light.

  2. Short (1 or 2 hrs) and low intensity flashes of white light are effective in bringing on the reappearance of rhythmic variations in darkness.

  3. We have been able to establish an isoquantic spectrum of action of the light. Two values of wavelength appears to account for a maximum sensibility of the shrimp: one in ultraviolet light and an other one, more important, in the green (λ=544 nm).

  4. In green light it is possible to obtain the same effect of light by decreasing the time of stimulation to 5 or 10 mn and in increasing the total quantity of energy. Significant responses are obtained with total energy greater than 10000 pE. cm‐2.

  相似文献   

16.
Abstract

Free beta-indoleacetic acid content in shoots of « Vicia sativa » seedlings grown in different environmental conditions. I. Seedlings grown in the dark and in the light. — Free IAA has been determined in shoots of Vicia sativa seedlings grown in the dark and in the light. The alcohol extract of the vegetable material has been submitted to several processes of purification (changes of PH and washing-out in ether, and successively column as well as thin layer chromatography). Lastly the IAA eluted with alcohol from the chromatographic slides is spectrometrically determined (λ = 280 mμ). The data show that the free IAA is contained to a greater extent in the seedlings grown in the dark in comparison to those grown in the light; this difference permaining in the samples of the same age as well as in those of the same height. The obtained data have been submitted to statistical analysis and both assays have shown to be highly significative.  相似文献   

17.
The following procedure for staining Negri bodies in sections is based on methods previously described by MacNeal, by Haynes, and by Richter:

Fixation:
  1. 1. Zenker's solution 4 hours at 37°C or Dominici's 3 hours.

  2. 2. 70% alcohol, 12 to 18 hours at room temperature.

  3. 3. 80% alcohol, about 5 to 6 hours.

  4. 4. 90% alcohol, about 4 to 6 hours.

  5. 5. Absolute alcohol about 16 hours.

  6. 6. Ether and absolute alcohol aa, about 8 hours.

  7. 7. 16 to 24 hours in the following mixture: celloidin 1 g., methyl salycilate 25 cc., abs. alcohol 25 cc., ether 25 cc.

  8. 8. Chloroform and paraffin, 2 to 3 hours.

  9. 10. Paraffin, 1 to 1 1/2 hours.

  10. 11. Embed.

staining:
  1. 1. Cut sections 4 to 5 μ.

  2. 2. Bring section to water and cover with Lugol's iodine for 10 minutes.

  3. 3. Decolorize with a 2% sodium thiosulfate (hypo).

  4. 4. Wash thoroly with water.

  5. 5. Cover with a mixture of equal parts of 0.5% phloxine and 1% eosin Y (National Aniline brand) and leave for 15 minutes.

  6. 6. Wash with water and stain 2 to 5 minutes in 0.1% azure B (National Aniline).

  7. 7. Wash with 96% alcohol and decolorize in a mixture of 2 parts absolute alcohol with 1 part clove oil, ordinarily for not more than 1/2 to 1 minute.

  8. 8. Dehydrate rapidly, clear, and mount in Yucatan Elemi.

  相似文献   

18.
Summary

In order to study a side of the influence of ultra-violet light on plants, the A. has harvested, 10 days after fertilisation, 1040 plants of Triticum vulgare Vill. and made many groups of them; then he sheared differently the ears and screened them partially from light so as to obtain, from the same subject, treated and untreated grains. Such ears he treated for different times of exposure with the light of a quarzlamp giving almost only ultra-violet rays. For the present, are here reported only results concerning the influence of ultra-violet light upon both germinating energy and power:

  • ultra-violet light stimulates the germinating power of grains, born from subjects treated no longer than 240 hours at a distance of 1 m from the lamp; longer treatments abate germinating power;

  • ultra-violet light stimulates, the germinating energy of grains born from subjects treated no longer than 120 hours; treatments during 120–240 hours don't notably modify it; treatments of over 240 hours reduce it very much;

  • according to the conditions in which this work has been done, a 10 days-irradiation seems to be, under every point of view, for the best. A 71/2 — days irradiation seems to be insufficient, a 121/2 — days one excessive, and hence prejudicial;

  • glumes are strong screening-organ for ultra-violet light;

  • ultra-violet light gives late appearing effects.

Since great difficulties usually occur whenever tests such as the present one are undertaken, the A. proposes some leading ways to previously settle the U.V.-rays dosimetry fit for every plant, in order to avoid wast of time and to get data of general value.  相似文献   

19.
In Fortführung seiner Untersuchungen über neotropische Acanthocinini veröffentlicht der Verfasser hiermit Beschreibungen von folgenden neuen Gattungen:
  • Nyssodrysilla nov. gen. mit N. irrorata (Melzer) aus Brasilien als Generotype, N. viliata (Melzer), comb, nov., aus Brasilien und N. lineata nov. spec, aus Peru.

  • Nyssodrysola nov. gen. mit N. stictica nov. spec. aus Peru als Generotype.

  • Sciadosurus nov. gen. mit S. albobrunneus nov. spec. aus Peru als Generotype.

  • Acarinozineus nov. gen. mit A. striatus nov. spec. aus Peru als Generotype und A. spinicornis nov. spec, aus Mexiko.

  • Alcathousites nov. gen. mit A. chaclacayoi nov. spec. aus Peru als Generotype.

  • Xylergatina nov. gen. mit X. pulcher (Lane) aus Peru als Generotype.

  • Xylergatoides nov. gen. mit X. asper (Bates) aus Brasilien und Argentinien als Generotype.

Ferner werden revidiert die Gattungen:
  • Xylergates Bates, Generotype X. lacteus (Bates), mit Beschreibung der beiden neuen Arten X. elaineae aus Peru und X. dorotheae aus Britisch‐Guayana.

  • Chaetanes Bates, Generotype C. setiger (Bates), mit Beschreibung der drei neuen Arten C. costulatus aus Peru, C. nigrobasalis aus Brasilien und C. apicalis aus Französisch‐Guayana.

  • Wo es erforderlich ist, sind Bestimmungstabellen gebracht und die Arten abgebildet.

  相似文献   

20.
Abstract

Researches on the morphogenesis of the genus Peyssonnelia Decaisne. — This paper reports the first result on morphogenetic researches in cultures of 3 species of the genus Peyssonnelia Decne. The development of Peyssonnelia rubra (Grev.) J. Ag. is of «Dumontia type »(CHEMIN, 1937) that one of Peyssonnelia squamaria (Gmelin) Decne. and of Peyssonnelia inamoena Pilger of «Naccaria type». According to our cultures results the morphogenesis of genus Peyssonnelia is of two type. Sample of P. squamaria and P. inamoena are collected in the gulf of Trieste (Nord Adriatic Sea) those of P. cfr. rubra in the Morlaix Bay (English Channel). Taxonomic value of the results are discussed.  相似文献   

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