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1.
Abstract

Soil microfungi in homogeneous areas of three plant communities of North Italy.—The soil microfungi associated with three different community types in Prealpine region of North Italy were investigated. Frequency values for the taxonomic entities isolated were calculated, based on occurrence at sampling sites, in each community. Most of the entities were quantitatively rare. The microfungal communities associated with Acer pseudoplatanus and Fraxinus excelsior, with Ostrya carpinifolia and with Fagus sylvatica appeared to be a distinctive group, even if many of them contained a substantial number of species wich are common with other vegetation types.  相似文献   

2.
Abstract

Cobalt, nickel and chromium effects on germination of Alyssum, during after-ripening and aging. Cobalt (2.5–20mM), nickel (2.5–25mM) and chromium (0.2-1mM) effects have been studied in seeds of three species of Alyssum, of which two, A. bertolonii and A. argenteum, endemics to serpentine soils and one, A. nebrodense, closely related to the others but endemic to the Madonie (Sicily) where it grows on limestone.

The results, expressed as percentage of germinated seeds (p), Kotowski coefficient of velocity (v) and germination average ratio (), have been subjected to statistical analysis.

The effect per mM is generally inhibitory, not significant for cobalt, weak but significant for nickel, more marked and significant for chromium, linearly correlated to concentration. The inhibition reaches its highest level when seeds are ripe, being significantly related to the control germination capacity ().

The values of the specific inhibition (effect/mM modditppτ) for all the three species are higher for chromium, which is more toxic than nickel, and increase from A. nebrodense to A. argenteum, showing that of the two serpentine endemics A. bertolonii is more tolerant both to nickel and chromium.  相似文献   

3.
4.
Abstract

Temperatures recorded in a olive-tree stem in 1961–1962. — In the Botanical Garden of Bari a temperature recorder has been placed, bearing 6 electrothermometers with platinum resistences having a sensitivity of 2,4 mm/C[ddot], with a recording approximation of 0,1 C[ddot].

The olive tree under examination is a grown-up tree, which has been pruned according to the local methode, and it belongs to a local breed named « Ogliarola leccese ».

Five thermometers have been employed as follows: 1rst in the air, hanging from the stem, m. 1,30, high; 2nd into the outer bark, cm, 0,5 deep; 3rd into the cambium, cm. 1,5 deep; 4th into the sap-wood, cm. 6 deep; 5th into the hearth-wood, cm. 22 deep.

The thermometers were all placed on the east side of the stem.

The figures and the graphs of the paper show that:

a) The whole stem of the specimen under examination has a mean temperature which is higher than that of the surrounding air.

b) The outer bark gets warmer than the air, during the day-time; during the night it gives up heat outside and inside, namely towards the stem tissues, particularly to the bark-cambium-sapwood zone, and also as far as the hearth wood zone.

c) The whole living zone of the stem (bark-cambium-sapwood) generally keeps temperature values intermediate between those of the outer bark and those of the air. The temperature values vary along the year.

d) In spring the cambium is warmer than the outer bark.

e) In winter cambium and sapwood generally have the same temperature. The temperature values recorded in this season are much lower than those of the outer bark and almost the same of those of the air.

f) The behaviour of temperature in cambium and sapwood is probably ruled by biological factors.

g) The hearth-wood keeps generally warmer than the air and cooler than other outer tissues. Its thermic rhytm is almost reversed in comparison with that of the outer tissues.

Il seems that hearth wood acts as an useful heat collector and distributor towards the living outer tissues during the diurnal and seasonal temperature remissions, at least in mild climates as that of Bari.  相似文献   

5.
6.
Il presente lavoro è stato eseguito nell' Istituto di Anatomia e Fisiologia Comparate dell' Università di Palermo, diretto dal prof. F.Raffaele. Il manoscritto relativo era pronto fin dall' ottobre dell' anno passato, ma il mio trasferimento da Palermo a Pavia e varie altre circostanze mi avevano finora impedito dal darvi l'ultima mano.Al prof.Raffaele che ha seguito con efficace interessamento queste ricerche e che ha voluto adesso gentilmente rivedere anche il manoscritto, i miei più cordiali ringraziamenti.  相似文献   

7.
Abstract

A cytophotometric study of proteins during mitosis in root tip meristematic cells of «Allium cepa L.». — Spectrophotometric analyses of the amount of Fast-green stainable proteins at different pH values (8,1; 6; 4; 2) have been accomplished in Allium cepa root tip meristematic cells during the four phases of mitosis. The results seem to indicate that: a) the highest absorption is detectable in correspondence of metaphase at each of the four pH values; b) the transition from prophase to metaphase is characterized by an increase of both proteins reacting at pH 8,1 (histones) and between pH 6 and pH 8,1 (neutral proteins); c) the transition from metaphase to anaphase is characterized by a loss of histones and of proteins reacting between pH 4 and pH 6 (acid proteins); d) the transition from anaphase to telophase is characterized by a loss of neutral proteins. The data are discussed in relation to the problem of chromosome coiling.  相似文献   

8.
Zusammenfassung Durch frühzeitige Zerstörung der ganzen primären Augenblase, bzw. des oberflächlichen Abschnittes der Augenanlage mit dem anliegenden Ektoderm, wurde beim Hühnerembryo die Entwicklung des ektodermalen Bestandteiles derHarderschen Drüse verhindert. Trotzdem legte sich der mesenchymale Bestandteil der Drüse an normaler Stelle an und entwickelte sich normal bis zum Ausschlüpfen; nur war die ausschließlich aus Mesenchym zusammengesetzte Anlage etwas kleiner als die normale Drüse. Vom 10. Tage der Bebrütung ab erscheint bei den operierten Embryonen der bindegewebige Bestandteil der Drüse als eine scharf konturierte, von den anliegenden Geweben gesonderte Masse von länglicher Form. Vom 16. Tage der Bebrütung ab dringen in die bindegewebige Masse kleine runde, stark granulierte Wanderzellen (vielleicht Makrophagen) ein; dasselbe wurde in der normalen Drüse beobachtet.Dadurch wird das Bestehen einer relativen Unabhängigkeit zwischen den beiden Bestandteilen derHarderschen Drüse, dem epithelialen und dem mesenchymalen Anteil, bewiesen; die Vermutung liegt also nahe, daß eine gewisse Unabhängigkeit in der Determination der beiden bestehe.  相似文献   

9.
10.
Zusammenfassung Die Uferspinne Arctosa perita (Latr.) verfügt über einen astronomischen Orientierungsmechanismus, durch den die Tiere imstande sind, wenn sie auf dem Wasser ausgesetzt werden, in der Richtung nach dem Ufer zu fliehen. Die Spinnen orientieren sich auf Grund des Sonnenstandes und des polarisierten Himmelslichtes und haben die Fähigkeit, die Tageszeit einzukalkulieren (Papi 1955b und c).Wenn eine Gruppe von Tieren gefangengehalten wird, dann nimmt bei den Fluchtversuchen die Streuung der Fluchtrichtungen zu. Dabei ist die Streuung der gesamten Fluchtversuche — wenigstens während der ersten 16 Tage — statistisch nicht verschieden, ob die Tiere nun a) in den natürlichen Belichtungs- und Temperaturschwankungen, b) im Dauerdunkel und in den Temperaturschwankungen oder c) im Finstern unter konstanter Temperatur gehalten werden. Was die Genauigkeit der Richtungsorientierung betrifft, so bleibt, trotz der stärkeren Streuung, die durchschnittliche Fluchtrichtung bei Gruppe a) bis zu 21 Tage lang korrekt, während sie bei den Gruppen b) und c) von der theoretischen Richtung immer mehr abweicht.Tiere, die im Finstern unter konstanter Temperatur gefangengehalten werden, orientieren sich bezüglich einer unbeweglichen Lampe bei verschiedenen Tageszeiten ungefähr so, wie wenn sie die Sonne wäre.Exemplare, die 3 Tage lang einem gegen den natürlichen Tag um 6 Std verschobenen Belichtungsrhythmus ausgesetzt werden, nehmen Orientierungswinkel an, die zur Zeit ihres künstlichen Tages korrekt wären.Ein innerer Tagesrhythmus (innere Uhr) regelt die Abweichung des Orientierungswinkels der Tiere. Im Laufe des Tages ändert sich der Orientierungswinkel nicht mit einer konstanten Geschwindigkeit, sondern mit einer solchen, die die Azimutgeschwindigkeit der Sonne auszugleichen sucht.Wenn die Tiere einige Stunden bei einer Temperatur von 4–5°C oder in 2°C gehalten werden, dann orientieren sie sich so, wie es einige Stunden vorher korrekt wäre. Der Gang der inneren Uhr kann also durch sehr niedrige Temperaturen verzögert oder gestoppt werden.Unter experimentellen Bedingungen können die Tiere in 8–10 Tagen neue Fluchtrichtungen erlernen.In der Besprechung werden die Resultate mit jenen verglichen, die bei anderen, einer astronomischen Orientierung fähigen Tieren erhalten wurden.

Dedicato al Prof. Karl von Frisch in occasione del suo 70 compleanno.  相似文献   

11.
Abstract

Environment studies and summer typology of the phytoplankton and phytobenthos along the Tropea coast (Calabria). II.—In this work the results are related of a study on the sea environment and the planktonic and benthonic algae, which were collected along the coast between Capo Vaticano and Briatico (Calabria—Tyrrenian Sea). This study is the continuation of a previous research.  相似文献   

12.
Riassunto L'autore ha condotto uno studio al microscopio elettronico sulla distribuzione e sulla genesi del glicogeno nelle cellule dell'embrione di pollo nei primi stadi dello sviluppo.L'autore riscontra che nelle prime ore di incubazione il glicogeno è presente in pressochè tutte le cellule del blastoderma, dove coesiste con inclusioni vitelline. Al 2° giorno di incubazione il glicogeno scompare in tutte le cellule che hanno interamente digerito le inclusioni vitelline, rimanendo invece solo in quelle che sono ancora rieche di vitello. Fanno eccezione le cellule del miotoma che, pur essendo sprovviste di vitello, nella terza giornata di incubazione accumulano glicogeno in notevole quantità, in coincidenza con la comparsa in esse délie miofibrille.L'autore ritiene ehe il glicogeno che si trova inizialmente nelle cellule embrionali si formi in gran parte per attività neoglicogenetica, a partire dal vitello contenuto nelle cellule medesime, Egli conclude che tale attività neoglicogenetica dapprima sia propria di tutte le cellule embrionali, fino a quando hanno inclusioni vitelline, e che poi essa rimane localizzata al solo epitelio del sacco vitellino che sempre contiene vitello.
Ultrastructural investigations on the distribution of glycogen in the cells of chick embryo in relation to the presence of yolk inclusions
Summary The distribution and genesis of glycogen in the embryonic cells of chickens in the first stages of development has been investigated electronmicroscopically.In the first hours of incubation the glycogen is present in almost all the cells of the blastoderm where it coexists with yolk inclusions. On the second day of incubation the glycogen disappears in all the cells that have completely digested the yolk inclusions and remains only in those that are still rich in yolk. The only exceptions are the myotome cells that, being that they do not have yolk in the third day of incubation, accumulate glycogen in notable quantities coincidental to the appearance of myofibrils.The author holds that the glycogen that is found initially in the embryonic cells has its origin, for the most part, from neoglycogenetic activity, starting from the yolk contained in the cells themselves. It is concluded that this neoglycogenetic activity initially is present in all the embryonic cells, while they still have inclusions, and then remains localized only in the epithelium of the yolk sac that always contains yolk.
  相似文献   

13.
14.
Riassunto è stato condotto uno studio su un gruppo di 296 pazienti affetti da atopia respiratoria residenti nella provincia di La Spezia. I soggetti erano sottoposti a prick test e/o RAST. Veniva considerata l'incidenza dei singoli allergeni. Dai dati emerge l'importanza delle Graminacee quali maggior responsabili di sensibilizzazioni al contrario di altre zone della Liguria ove è predominante la Parietaria.
Summary In the present investigation 296 patients with respitatory atopy, resident in La Spezia have been studied. The diagnosis was estabilished on the basis of prick test and RAST. We evaluated the incidence of each allergen. We reported the aetiological importance of Grasses in La Spezia, whereas Parietaria is less predominant.
  相似文献   

15.
P. Giorio  V. Nuzzo 《Plant biosystems》2013,147(2):322-335
Abstract

Canopy light interception (CPFDInt), spectral irradiance, leaf water potential, gas- exchange and optical properties were measured in an irrigated vineyard (Vitis vinifera L. cv Montepulciano) trained to the so-called tendone system in which leaf area index (LAI) was varied by means of 50% (T50) or 75% (T75) cluster removal. The 20.5 t ha?1 yield in the unthinned treatment (UT) decreased by only 36% in T50 and by 52% in T75. LAI and CPFDInt similarly increased until summer pruning when LAI was 1.75 m2 m?2 in UT, and 25.6% or 62.2% higher in T50 and T75, respectively. The two thinned treatments had only 12.4% higher CPFDInt than in UT (1167.1 μmol m?2 s?1) due to the increased leaf self-shading. The red-to-far red ratio (R: FR) was as low as 0.10 below the canopy. Light-saturated CO2 assimilation (A max) in June averaged 14.4 μmol m?2 s?1 in sun-exposed leaves, and 7.6 μmol m?2 s?1 in shade leaves. By contrast, the apparent quantum yield of CO2 assimilation (φe) was not significantly affected by leaf position, averaging 0.029 and 0.070 mol mol?1 in June and October, respectively. Middle and low canopy leaves had only 27 or 6%, respectively, of the top canopy leaves actual CO2 assimilation rate.  相似文献   

16.
Abstract

Inventory of Corallinales of the Mediterranean Sea: taxonomic aspects. - The aim of the present work is the drawing up of a critical inventory of Corallinales of the Mediterranean Sea. This research has been based upon a census of 320 works published since 175 years, upon direct collections and sample exchanges. A census of 88 species of Corallinales (with forms and varieties), made up on the basis of about 5000 records, has been taken. 34 of the 88 species are considered “species dubiae aut rariter inventae”, it has been reported also “species inquirendae” and “species addendae”. From this census it results that there are some taxonomic problems about genera attributions (Lithophyllum, Pseudolithophyllum, Titanoderma, Neogoniolithon, Spongites, Goniolithion, Leptophytum), species attributions of articulated Corallinales (Corallina elongata, C. officinalis e Haliptilon squamatum) and non-articulated Corallinales (Fosliella ischitana, Lithophyllum (Titanoderma) trochanter, Spongites fruticulosus). Definition of these taxonomic attributions might condition not only studies of phytogeographical distribution of these algae but also every successive interpretation.  相似文献   

17.
Abstract

Seasonal variations of mineral nutrients and trace elements in Fagus sylvatica L. leaves at Vallombrosa (FI). - During the vegetative periodo 1987 monthly samples of beech leaves were collected in Vallombrosa forest area to determine the nutritive situation of beech trees by leaves analysis. Among nutrients, potassium appears the worst supplied one. Even copper is present in very low values, under the critical level. Heavy metals as manganese, aluminium, lead, cadmium and also iron show a clear increase during the vegetative season.  相似文献   

18.
Abstract

A preliminary account on some mountain lakes of the Southern Apennines. Phytoplankton investigation on three ponds of the Monte Sirino (Basilicata).—Phytoplankton standing crop and species composition have been studied in three ponds of the Southern Apennines. The observations carried out throughout ten months in 1975, showed a great number of species present in the Remmo pond, mainly diatoms, desmids, green algae, and blue-green algae. In the Sirino pond only diatoms and Chrysophyceae were present.

In comparison, in the Zapano pond, the phytoplankton was scarcely represented but the occurrence of some species of green algae may suggest a eutrophic water condition. On the basis of the peculiarities both of species composition and biomass, the major water bodies may be considered oligotrophic.  相似文献   

19.
Abstract

On the occurrence in Southern Italy of some benthic marine algae rare to the Mediterranean Sea. - The Authors report the occurrence along the coast of Southern Italy of the following species that resulted rare to the Mediterranean Sea: Antithamnion piliferum Cormaci et Furnari; Bonnemaisonia asparagoides (Woodward) C. Agardh (tetrasporophyte); Corynophlaea flaccida Kuetzing; Fosliella farinosa (Lamouroux) Howe: of this very common species, the occurrence of thalli with propagules is reported; Hypnea cervicornis J. Agardh; Jania adherens Lamouroux, new to Italy; Mesogloia lanosa P.L. et H.M. Crouan, new to Italy; Pneophyllum confervicolum (Kuetzing) Chamberlain f. minutulum (Foslie) Chamberlain, new to the Mediterranean Sea; Polystrata fosliei (Weber van Bosse) Denizot, new to Italy; Rhodymenia delicatula Dangeard; Spermothamnion johannis G. Feldmann-Mazoyer: of this common species, the occurrence of bisporocysts in monoic gametophytes is reported; Vickersia baccata (J. Agardh) Karsakoff.  相似文献   

20.
Abstract

Nucellar embryogenesis in undeveloped ovules in some navel orange cultivars. - Nucellar embryogenesis has been studied in some cultivars of navel orange, Citrus sinensis (L.) Osbeck. Histological observations have been carried out in undeveloped ovules excised 2, 4, 6, 8 months after anthesis. Ovules under study derived a) from flowers naturally pollinated or hand-pollinated with pollen of Poncirus trifoliata (L.) Raf.; b) from emasculated flowers, and c) from flowers deprived of stigma. In absence of pollination, as well as in absence of fertilization, the nucellar embryos reached the globular stage.  相似文献   

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