I Lomasomi: Loro Probabili Rapporti con la Crescita per Distensione della Parete Cellulare

Abstract

« 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.

In this paper it has been reported that the number of lomasomes per cell was sharply decreased when Avena Coleoptiles were illuminated per 3 hours. During this period of time also the growth of the Coleoptiles was inhibited about 8%. These data seem favorable to the hypothesis that lomasomes are tigtly involved in the mechanisms controlling the expansion growth of the cell wall.     

Ricerche sulla Vegetazione della Valsesia

Summary

The present work, forming a part of the research on the Valsesian vegetation, is an investigation of the botanical aspects of one of the tributary valleys of the Mastallone torrent, the Sabbiola valley.

The valley has steep flanks cut into compacted crystalline rock; this morphology is very different from other valleys cut through esasily erodible rock, and with gentle slopes, and has marked influence on the vegetation.

At the base of the valley a forest of Alnus incana and Fraxinus Ornus and, ascending, a stand of chestnut trees not very extensive was noted.

Betula pendula was noted as high as 1200 meters (above sea level). Beech trees, more or less heliophilus or acidophilus are extended lo higher elevations, up to 1500 m., and started at about 850–900 m. The hypsophylous conifers were missing and the “cacuminale” vegetation was neither very extensive or typical, because even the highest elevations of this valley are relatively low for this type of vegetation.

The study of the vegetation of this valley upon completion will be incorparated and inte preted together with the results of other research on the Valsesian region.     

Ricerche Sull'ultrastruttura dei Tubi Cribrosi di Piccioli di Foglie di Edera

Abstract

The ultrastructure of sieve tubes in leaf petioles of HEDERA HELIX. — The structural organization of the sieve elements in Hedera leaf petiole at the beginning of the second year of life has been studied. At this stage of life the sieve tubes are completely developed, but still in full activity.

Their plasmatic structures, though altered, show that they are still alive. The cytoplasm forms a parietal layer; mitochondria, endoplasmic reticulum and plastids are present although very peculiar in aspect. The cytoplasm is bounded externally by a plasmalemma; on the contrary no tonoplast is detectable.

The data reported in this paper are favourable to the idea of an active partecipation of the sieve tubes in the translocation of organic solutes, in agreement with the findings concerning the oat coleoptile.     

Ricerche Sulla Vegetazione della val Gesso

Abstract

An interesting discovery in the Maritim Alps flora. ARTEMISIA CAMPHORATA Vill. with galls of DIARTHRONOMYIA KIEFFERI Trotter. Its geographical distribution and phytogeographical analysis. — The Author signals the finding, in the Maritim Alps flora, of some stations of an interesting discovery: Artemisia camphorata Vill. with galls of Diarthronomyia (Rhopalomyia) Kiefferi Trotter, and explains the characteristics of this Cecidomyide, (gall-midge).

He exhibits the results obtained through inquiries (investigations) directed to define the geographical area of Diarthronomyia Kiefferi, in reference to that of its host plant, of which the zoocecidium is exclusive.

The author makes also a map of the area and analyses the phytogeographical characte ristics and the mediterranean physiognomy of the new found stations.     

Ricerche chimico-istologiche su la lignificazione della membrana

Riassunto

L'A. studia il comportamento della membrana di fronte ad alcune soluzioni coloranti a reazione attuale diversa. Stabilisce il potere di assunzione dei colori da parte della lignina, dello xilano, della cellulosa, del legno, con il semplice esame microscopico e con esami colorimetrici, e viene a stabilire alcune nuove norme per giudicare su la lignificazione della membrana. Egli stabilisce che quanto più acida è la soluziene colorante in cui si manifesta la colorzaione con il verde di metile, con il verde di malachite, con il bleu di metilene, con il violetto di genziana, tanto più alto è il grado di lignificazione della membrana.     

Prime Ricerche sulla Fisionomia Enzimatica Caratteristica della Fotosintesi

Summary

The rate of oxidation of glucose-6-phosphate, ribose-5-phosphate, fructose-1,6- phosphate, iso-citrate and malate in extracts from green and etiolated pea leaves was determined, using the triphenyltetrazolium technique.

Glucose-6-phosphate, ribose-5-phosphate, and fructose-1,6-phosphate, in the presence of added TPN, where oxidized at a rate about twice higher in the extracts from green than in the extracts from etiolated leaves. Iso-citrate, in the presence of TPN, fructose-1,6-phosphate, in the presence of DPN, and malate, in the presence of either TPN or DPN, were oxidized at about the same rate in the two types of extracts.

These data seem to indicate a preferential synthesis of enzymes involved in the metabolic cycle of phosphorylated sugars during the transition of the leaf from the etiolated to the photosynthetising physiognomy. They seem also favourable to the view assigning to this metabolic system a primary importance in the anabolic pathway of photosynthesis.     

Ricerche sui microrganismi produttori della fioretta nel vino

Zusammenfassung Aus 54 italienischen Weinproben mit Kahmhaut wurden 119 Reinkulturen isoliert, die aus den sporenbildenden Hefen Zygopichia chiantigiana Castelli, Pichia Derossii Castelli, Pichia membranae faciens Hansen sowie einer neuen Varietät dieser Art, var. acidificans, bestanden. Ferner fanden sich die nicht sporenbildenden Hefen Mycoderma cerevisiae Desmazières, M. Lafarii Janke, M. vini De'Rossi, M. acidificans De'Rossi, M. tenax De'Rossi, M. duplex De'Rossi und eine neue Varietät dieser Art, var. degradans. Ferner wurden noch acht nicht bestimmbare Mycoderma-Stämme gefunden und beschrieben. Alle festgestellten Formen unterscheiden sich stark in ihrer Fähigkeit zum Alkoholverbrauch und der Säurebildung.     

Ricerche sulla distribuzione altimetrica della vegetazione in italia

This contribution introduces the ongoing research on herbaceous bamboos started by the University of Florence (FT herbarium), the Universidad de Panama (PMA herbarium) and the Smithsonian Tropical Research Institute in 2011. The main goal of this project consists in collecting field data, in order to provide updated material to be used in a phylogenetic analysis to improve the knowledge of the complex tribe Olyreae.     

Ricerche sull'orientamento astronomico di anfipodi litorali della zona equatoriale

Con 13 figure nel testo     

Ricerche biochimiche,biofisiche e istochimiche intorno al problema della metacromasia

Con 10 Figure in bianco-nero e 5 a colori nel TestoIl presente lavoro è stato eseguito usufruendo in parte anche di un contributo del Consiglio Nazionale delle Ricerche.     

Ricerche sulla differenziazione e sull'accrescimento della cartilagine in condizioni meccaniche sperimentalmente modificate

Riassunto Allo scopo di studiare le ripercussioni di profondi mutamenti delle condizioni meccaniche ambientali sulla differenziazione e l'accrescimento della cartilagine della sclera, si determinÒ in una serie di embrioni di polio al 4⁰ giorno di incubazione un collasso dell'abbozzo dell'occhio destro. In conseguenza del collasso, il bulbo oculare, i cui singoli costituenti si differenziano in modo tipico, si accresce in misura considerevolmente ridotta in confronto all'occhio dell'altro lato, il cui sviluppo non fu turbato. Già due giorni dopo il collasso del calice retinico, il mesenchima che lo circonda e che è destinato a differenziarsi in gran parte nella cartilagine della sclera, costituisce una massa più spessa che di norma ma assai meno estesa in superficie.A partire dalla fine del 6⁰ giorno d'incubazione, tale mesenchima si differenzia in cartilagine; in quest'ultima le cellule sono più addensate dal lato leso che da quello indenne. La densità dei condrociti per unità di volume di cartilagine non muta in modo significativo durante tutto lo sviluppo embrionale. La percentuale di condrociti in mitosi nella sclera dell'occhio ridotto, decresce un po' più rapidamente che nella sclera normale a partire dal momento nel quale inizia la differenziazione dell'abbozzo della sclera in cartilagine; invece, la sintesi di solfato di condroitina nella sostanza intercellulare, saggiata con lo studio dell'incorporazione di radiosolfo per un periodo di 24 ore, non presenta differenze apprezzabili nella sclera dell'occhio ridotto in confronto a quello che si accresce normalmente.La quantità assoluta di cartilagine che costituisce la sclera dell'occhio ridotto è considerevolmente minore di quella dell'occhio normale. Risulta dalle presenti ricerche che la differenza nell'accrescimento fra le sclere dei due occhi dipende non da variazioni dell'accrescimento interno ma da una cospicua riduzione dell'accrescimento apposizionale della sclera dell'occhio ridotto, sopratutto in corrispondenza del margine laterale della sclera al limite con la cornea (limbo sclerocorneale). In altre parole, nell'occhio ridotto vengono a mancare le condizioni meccaniche indispensabili per la progressiva estensione in superficie della sclera, la quale è dovuta ad un intenso accrescimento apposizionale al margine sclero-corneale.

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Zusammenfassung Ziel vorliegender Untersuchungen war es, die Folgen von starken Veränderungen der mechanischen Bedingungen des Milieus auf die Differenzierung und auf das Wachstum des Skleralknorpels festzustellen. Bei einer Serie von Hühnerembryonen wurde am 4. Bebrütungstage ein Kollaps der rechten Augenanlage veranla\t. Während die Differenzierung der einzelnen Bestandteile durch den Kollaps des Augapfels nicht beeinträchtigt wurde, war sein Wachstum erheblich reduziert, in Vergleich mit dem des gegenseitigen Augapfels, dessen Wachstum ungestört war. Schon 2 Tage nach dem Kollaps des Augenbechers kommt es zu starken Veränderungen in der Form des umgebenden Mesenchyms, welches sich grö\tenteils zum Skleralknorpel differenzieren soll; die Mesenchymmasse wird plumper; ihre Flächenausdehnung wird erheblich reduziert. Vom Ende des 6. Bebrütungstages ab differenziert sich das Skleramesenchym zu Knorpel, in dem die Zellen im Vergleich zur unversehrten Seite verdichtet erscheinen. Die Dichtigkeit der Knorpelzellen je Volumeneinheit von Knorpel bleibt während der ganzen Entwicklung des operierten Embryos unverändert. Der Prozentsatz der Mitosen der Knorpelzellen in der Sklera des reduzierten Auges sinkt in Vergleich mit der normalen Sklera von dem Moment etwas rascher ab, in dem die Differenzierung der Skleraanlage in Knorpel stattfindet. Dagegen wurden, wenn man die Einverleibung der Menge von Radioschwefel in die Grundsubstanz während einer Periode von 24 Std untersucht, keine nennenswerten Unterschiede im Skleralknorpel des operierten Auges in Vergleich zu dem des gegenseitigen Auges konstatiert; dadurch wird bewiesen, da\ die Synthese von Chondroitinschwefelsäure in der Knorpelgrundsubstanz durch die Reduktion der Sklera nicht beeinträchtigt wird.Es ergibt sich aus vorliegenden Untersuchungen, da\ die absolute Menge des Knorpels der Sklera in Vergleich mit dem normalen Auge erheblich reduziert wird; doch hängt die Reduktion nicht von einer Verminderung im inneren Wachstum ab, sondern von der Reduktion des appositionellen Wachstums in der Sklera des reduzierten Auges, besonders am lateralen Rande der Sklera, an der Grenze mit der Hornhaut (Limbus Corneae). Kurz, es fehlen im reduzierten Auge die mechanischen Bedingungen für die progressive Ausdehnung in der Fläche der Sklera, welche durch ein intensives appositionelles Wachstum am Limbus Corneae hervorgebracht wird.

     

Ricerche sul meristema apicale della radice II. II contenuto di coenzimi riboflavinici

Abstract

RESEARCHES ON ROOT APEX MERISTEM. II. RIBOFLAVINE COENZYMES. — FMN and FAD contents have been measured (by the method of BURCH et al.) in the roots of etiolated pea seedlings. It has been found that FMN and FAD content is higher, when referred to fresh weight, in the 2 mm. apical segment than in the next 2–4 mm segment.

On a protein basis, FMN is more abundant in the 2–4 mm segment than in the 0–2 mm apical segment.

The opposite is true for FAD (see table). The apical (meristematic) segment is therefore characterized by a higher FAD/FMN ratio (its value is 1) than the next 2–4 mm segment, where the ratio FAD/FMN is 0.29.     

Ricerche sul meccanismo di azione della cocliobolina. A: effetti della tossina su fettine di tubero di patata in riposo

Abstract

STUDIES ON MECHANISM OF COCHLIOBOLIN ACTIVITY. A: EFFECTS OF THE TOXIN ON FRESH POTATO TUBER SLICES. — Cochliobolin, a toxic compound produced by Helminthosporium oryzae, causes inorganic phosphorus leakage from fresh potato tuber slices, higher amounts being found in incubation media with higher toxin concentrations and for longer incubation periods. Organic compounds, also, are released by potato tuber slices, like phenolic products, large amounts of sugars, and some aminoacids, alanine, lysine, tyrosine, valine and γ-aminobutirric acid, which have never been observed in the incubation meida of untreated slices. Cochliobolin uptake by fresh potato tuber slices does not take place actively or, anyhow, at a metabolic level. Indeed, neither 2,4-dinitro-phenol (at concentration, pH, and incubations periods apt to reduce active uptake), nor low temperatures (0–2°C) prevent toxin uptake. Potato tuber slices are not affected by cochliobolin, unless kept at 25°C, and this fact suggests that while toxin uptake does not interest metabolic pathways, it might affect some phase, or structure, essential to cell metabolism. The locus of toxin activity seems therefore to be identified with its influence on cell absortion and retention activities, of products essential for metabolic processes. Thus the impairing of cell permeability, possibly affecting the processes or the structures which regulate the active uptake, seems to be, at the moment, the only evident interpretation of the phenomena observed.     

Ricerche sulla flsiologia della produzione di tossine in colture di Helminthospobium maydis Nishik. et Miy

Abstract

STUDIES ON THE PHYSIOLOGY OF TOXIN PRODUCTION BY HELMINTHO-SPORIUM MAYDIS NISHIK. ET MIY. CULTURES. — Helminthosporium maydis produces under artificial culture toxic metabolites, which are responsible of a reduction of wheat and corn rootlets growth, severe alterations in tomato shoots and young corn plants, and growth inhibition of some microrganisms.

Cultural conditions for growth and toxin production were studied. Different strains of the fungus vary in their ability of toxin production, the highest amounts being produced by each strain by somewhat different conditions. At least one toxic metabolite can be extracted by chloroform from the cultural filtrates, but probably more than one toxin is produced, and of them at least one is not extracted with organic solvents. Toxic substances can be extracted from the mycelia, but it is not yet possible identify the toxins obtained by the extraction of the mycelia with one or more of the toxic metabolites obtained by extraction of the cultural filtrates.     

Ricerche sui pigmenti fotosintetici di Gracilaria verrucosa (Huds.) Papenfuss. Dosaggio quantitativo della ficoeritrina

Abstract

Research on photosynthetic pigments from Gracilaria verrucosa (Huds.) Papenfuss. Quantitative analysis of phycoerythrin. – Among biliproteins of Rhodophycean algae, phycoerythrin is very interesting for constant distribution, in large amounts, in the different species. Phycoerythrin's extinction coefficients have been already calculated for some Bangiophycean and only two species of Rhodophycean algae. In this work we have analyzed all photosynthetic pigments and isolated pure phycoerythrin from Gracilaria verrucosa (Huds.) Papenfuss [= Gracilaria confervoides (L.) Grev.] belonging to Gigartinales. The aim of our research was to evaluate the quantitative ratio between this pigment and the others in a sistematic group for which there are only qualitative data. Phycoerythrin of Gracilaria is the R-classical type, with three absorption maxima. Average values of absorption coefficients, calculated on a large number of samples are E₁ ^%cm (565 nm) = 53.8, E₁ ^%cm (540 nm) = 48.4, E₁ ^1%cm (498 nm) = 49.1. These values are different from those obtained for R-phycoerythrin of Ceramium rubrum and B-phycoerythrin of Rhodochorton floridulum, both species belonging to Floridean algae. Our several experiments by chromatography and gel-electrophoresis process have demonstrated that the R-phycoerythrin we isolated is substantially pure. Thus we suggest that different absorption coefficient values are due either to a more complicated protein in the pigment molecule or to a different chromophore/protein ratio. This could result very interesting for the chemotaxonomic and phylogenetic aspect, but the small number of algae till now analyzed does not allow to draw any general conclusion.