Sulla Presenza di Ificellarioli e di Conidi in Mieobionti Lichenici Coltivati in « Vitro ». Riassunto

Abstract

On the presence of « hyphycellariola » (swollen celles) and conidia in three lichenized fungi cultivated « in vitro ». — The Authors refer to the presence of « cellariola » (and « hyphycellariola ») found in pure cultures « in vitro » of the mycobiont of Xanthoria parietina and describe the morphology of conidia in the fungus isolated from Sarcogyne similis and Acarospora fuscata.

As far as the « cellariola » and « hyphycellariola » are concerned, it is the first note relative to the mycobionts of Lichens.

The Authors report the data of the utilized medium and the morphological observations.

This previous studies will be intensified by further research.     

Fissazione di C14O2 in Colture di Tessuti Vegetali « in Vitro »

Abstract

C¹⁴O₂ fixation in plant tissues « in vitro ». — In the present work it has been examinated the autotrophic and heterotrophic CO₂ fixation of explants of « Helianthus tuberosus » « in vitro » and the photosyntetic efficiency of leaves produced from buds of « in vitro » explants of « Cichorium intybus » compared with that of mature leaves from normal plants of the same species. From our results it is evident that « in vitro » explants of « Helianthus tuberosus », grown, in the light, are able to autotrophically incorporate C¹⁴O₂; the distribution of the radioactivity into the various fractions shows a large influence of the light on the neutral fraction containing sugars (50% of the total radioactivity). In the chlorophyllous explants the dark CO₂ fixation is obviously of heterotrophic type: 97% of the total radioactivity is incorporated in amine acids (43%) and the organic acids (53%); on the other hand in the dark grown explants the radioactivity is differently distributed between amino acids (59%) and organic acids (39%). Mature leaves from normal plants and leaves produced from buds of « in vitro » explants of « Cichorium intybus » incorporate the same quantity of C¹⁴O₂ when expressed per mg of chlorophyll; the different distribution of the radioactivity in the neutral and acid fractions could be explained in terms of a different utilization pathway of the photosynthates in the two tissues.     

Saxifraga Berica (Béguinot) D. A. Webb E Asplenium Lepidum Presl Sui Colli Berici

Abstract

«Saxifraga berica» (Béguinot) D. A. Webb and «Asplenium lepidum» Presl on the «Colli Berici». – We have identified a new association in the small caverns of the calcareous rocks in the hills of the north-eastern zone of the «Colli Berici», rising from the Italian plain near Vicenza. We have adopted for this association the name: ADIANTO-SAXIFRAGETUM BERICAE. This phytocoenose is characterized by the endemic «Saxifraga berica». We have found new stations of this remarkable plant and reported some features of this species to complete the diagnosis of D. A. Webb. In two station of this association we have found also the rare «Asplenium lepidum», new for this region.     

Sulla Terminologia dei Processi Apomittici

Summary

The Author observing the great disagreement of the terminology usually adopted for the apomictic phenomena, examines the whole series of the phenomena noted both in regards of the formation of the gametophyte and of the embryo. The forming of the gametophyte is fixed on the base of nature of its original cell, normally a haploid spore or »haplospore« (phenomenon of the »haplospory« following the regular meiosis), rarely a diploid spore or »diplospore« (phenomenon of the »diplospory« following the irregular meiosis, as for instance in the case of restitution nucleus, etc.). The original cell can be at least represented by the same cell that usually is the spore mother cell, whether for the outward causes, or for inward causes is lacking the usual reductional process. For the failure of the meiotic process, such a cell cannot be called »spore«.

A cell of the somatic tissue of the sporophyte can even become the original cell of the gametophyte always in case of the absence of the meiosis. These two last cases of apospory are respectively called: »somatic apospory« and »gonial apospory« (= germinal apospory) (Chiarugi 1926).

The formation of the embryo is fixed on the base of the nature of the fecundation. The principal phenomena of the fecundation are represented by the following cases: »amphigamy« (or eugamy, or gamy), »semigamy, »pseudogamy«, »apogamy« »parthenogenesis«. The A. uses the term »apogamy« both for the diploid eggs and for the haploid eggs in which the stimulation of the division is produced by the pollen-tube or by male nuclei, in absence of the gamy.

The term »parthenogenesis« is restricted to the division of the haploid or diploid eggs in which the stimulation is not caused by pollen-tube nor even for the great reason, by the male nuclei existing in it.     

La Vegetazione e L'ecologia Di Pratofiorito (Appennino Settentrionale)

Abstract

Ecology and vegetazion of mount Pratofiorito. — The author examines position, climatic conditions, geological nature and vegetation of Mount « Pratofiorito » in the Tuscan Appennine.

Mount Pratofiorito is a residue of secondary rocks and derived soil surrounded by tertiary and quaternary rocks and soil.

Its vegetations is actually constituted by grass-land and so it differs-from that of the neihbouring mountains which comprises the flora has been made. This list was then comparend with spades found in the adjacent beech and helm-oak zones.

From these comparisons one can deduce thath the meadow of « Graminaceae » and « Cyperaceae » growing on Mount Pratofiorito may bed considered as a grass-land resulting from the degradation of an arboreal zone, problably from a beech-wood.     

Crepis Bursifolia L., Nuova Stabile Inquilina della Flora Ligustica della Riviera di Ponente

Abstract

«Crepis bursifolia » L., new permanent tenant of the flora in west ligurian coast. — The author declares the permanent presence of « Crepis bursifolia » L. in Liguria, and informs about new stations of this species along the western riviera. The relates, furthermore, the unfavourable results of his close investigation to verify the eventual presence of further station of « C. bursifolia » L. found by former researcher.     

Ulteriore contributo alle conoscenze sul « Denti de cani » (X Haynaldoticum sardoum Meletti e Onnis)

Abstract

Further data on « Denti de cani » (X Haynaldoticum sardoum Meletti e Onnis). – The authors defin the taxonomic position of « Denti de cani » (X Haynaldoticum sardoum Meletti e Onnis). It is characterized by the presence of two forms differentiated for morphological features and behaviour.     

Ricerche Sulla Rigenerazione in Coltura Di Pterocladia Capillacea (Gmel.) Born. Et Thur

Abstract

Research on the regeneration in «Pterocladia capillacea» (Gmel.) Born, et Thur. cultured «in vitro». – It has been show that small segments (even 0,3 cm. long) of the thallus of «Pterocladia capillacea» undergo the regeneration «in vitro» of adventitious buds. Sea water enriched according to MIQUEL'S formula (1890) was used for the culture. Adventitious buds were present on both the cut-surfaces of the intercalary segments. Both surfaces regenerated, suggesting the absence of clear polarity for regeneration; howewer, usually one cut-surface showed more vigorous adventitious branches than the other one. The possibility that the predominance of one surface could be related to a polarization of the flow of nutrients from the parent segment has been discussed. The thallus originated «in vitro» is very similar to the creeping axes and the formation «in vitro» of thallus similar to that of the erect frond was never observed. 0,1γ/ml. IAA promoted regeneration and stimulated the growth of adventitious buds. IAA stimulated also the growth of the apical portion of the erect fronds. 10^?5M 2-chloro-ethyl trimethyl-ammonium chloride (CCC) stimulated regeneration and the growth of the tips of the main axis and lateral branches of apical segments. Higher CCC concentrations (10^?3M) inhibit regeneration and at the same time all the tips were necrotized; consequently some outgrowths appeared along the original axes. Such phenomenon was interpreted as a new type of regeneration obtained without any injury. Data reported in this preliminary communication represent a good approach for new study on the biochemical aspects of regeneration.     

Contributo all'embriologia delle Asteraceae: VI

Riassunto

Il gametofito fetaminile di Anthemis arvensis L. mostra uno sviluppo quanto mai interessante, perchè insieme al tipo « Crucianella » con oangio emisporiale (ca. 75%) si trova pure un altro tipo di sviluppo, il già noto tipo « Pyrethrum parthenifolium » con oangio monosporiale (25% ca.). Il gametofito 16-nucleato tipico tuttavia non è mai stato riscontrato; invece l'Autore ba osservato la presenza del sottotipo 10-nucleato, che è stato recentemente scoperto e che ha preso il nome di sottotipo « Ulmus ». I due tipi sopraddetti sono collegati dalla possibilità di uno sviluppo secondo il tipo « Vittadinia » con oangio monosporiale, che si deve considerare come un tipo intermedio fra i due.

Nella presenza di questi tipi di sviluppo in una stessa specie l'Autore trova una conferma della assoluta dipendenza del tipo « Crucianella » dai tipi tetramegasporiali facenti capo al tipo « Pyrethrum parthenifolium ».     

Microbiocenosi fotosintetiche delle Terme « Selinuntine » di Sciacca (Sicilia)

Abstract

Photosynthetic microbiocenose of the « Selinuntine » Hot Springs in Sciacca, Sicily. - Cyanobacteria belonging to the genus Oscillatoria, typical of thiobiotic habitats, were predominant in the photosynthetic microbiocenose of the « Selinuntine » Hot Springs in Sciacca. Oscillatoria animalis was prevalent in the thermal microbial community having the highest temperature and sulfide values suggesting a particular physiology requiring the presence of low redox compounds for its growth. Anoxigenic photosynthetic bacteria constitued a minor component of the biocenose.     

Effets de l'iode sur la croissance des frondes d'Asparagopsis armata (Rhodophycées,Bonnemaisoniales) obtenues en culture à partir de rameaux à harpons

Abstract

Effects of iodine on the growth of the « fronds » of Asparagopsis armata (Rhodophyceae, Bonnemaisoniales) in culture from spear bearing branches. – By adding doses of 5 μ moles per litre of iodide or iodate to a medium changed every six days, maximum growth for the « fronds » of Asparagopsis armata is obtained. Initial doses of iodide and iodate higher than 15 μ mole per litre inhibit the growth of this alga.     

Nuovi Dati Sulla Distribuzione Di Isoétes Malinvernianum in Lomellina

Abstract

New data on the distribution of « Isoëtes malinvernianum » in Lomellina. — The Author relates the discovery of many new stations of Isoëtes malinvernianum in Lomellina (Province of Pavia). Many observations carried out in these new localities and in the most part of the already recorded localities near Novara and Vercelli have allowed him to modify some convincements on the habitat of this well known endemism. So he reports that Isoëtes malinvernianum vegetates not only in the waters of « fontanile » but also in waters of the most different sources, that this species is not solitary but accompanied by many species as Callitriche palustris, Fontinalis antipyretica, Sagittaria sagittifolia, Vallisneria spiralis, Potamogeton crispa and few other species more. Isoëtes malinvernianum, besides, is not damaged by dredge works in the canals and is present not only in morainic soils and in the diluvial soils transformated in ferreto but also in the terraced flood named with old terms as « Terrazziano » or « Diluvium recente » and in the diluvial soils of the « Alluvium ». Now at least it is not possible to ascribe plant communities of which Isoëtes malinvernianum makes part to a well defined association.     

Le « Pedicularis » della serie « Foliosae » Maxim. della Flora italiana

Abstract

The « Pedicularis » of the series « Foliosae » Maxim, in the Italian Flora. – The paper deals with the badly known distribution of Pedicularis foliosa L., P. hoermanniana K. Maly and P. hacquetii Graf (ser. Foliosae Maxim.) both in Europe and in Italy. The illyrian P. hoermanniana occurs also in central Italy, being therefore a typical periadriatic entity. It completely substitutes the two others species in the Italian peninsula.     

Insediamento e Diffusione di Buddleia Davidii Franch

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.     

Ricerche Cariologiche e Embriologiche Sul Genere Rudbeckia (Asteraceae)

Summary

The author describes the different modalities of the cellularisation of the adult gametophyte of Rudbeckia laciniata L. The several cases are arranged according to the number and the type of differentiation of the cells of the gametopyte. Of each type it is stated the frequency, calculated in about 500 cases.

The author remarks that the differentiation of the single cells is owing to »an effect of the position«, which exists in the displacement of the nuclei of the gametophyte regarding the proendospermatic cell, to which cell, however, one can attribute a pre-eminent »power of organization«. The displacement of the nuclei is after all the consequente of the stage of the » polarisation «.     

“Eumeiosi” e “Meiosi Apoomeotipica” Seguita da “Mitosi a Diplounivalenti” Nel Tessuto Somatico di Sambucus

Summary

The Authors describe in Sambucus nigra L the occurrence of the » apohomeotypic teiosis « followed by a »mitosis with diplounivalents « (Battaglia 1945, 1947) in ae somatic tissue of the style. The AA. observed also the occasional formation f four haploid nuclei and then the occurence of the »eumeiosis« (Battaglia 1945).     

Inibizione Da Saccarosio Della Demolizione Delle Riserve Lipidiche in Cucurbita Maxima

Abstract

Inhibition by sucrose of utilization of storage lipids in germinating seeds of «Cucurbita maxima». – Previous work demonstrated that sugars inhibit almost completely the respiratory utilization of lipid in isolated cotyledons from germinating «Ricinus communis» seeds as well as in a yeast, «Rhodotorula gracilis». This research was carried out with the aim to further characterize this phenomenon; the material used are the cotyledons and the embryonic axes of «Cucurbita maxima» var. «mammouth», where the lipid contents markedly decrease during the first 72 hours of germination. By incubating the embrional axes, isolated from 48 hours germinating seeds in 0.1M sucrose it was observed: a) a rise of the R.Q. from 0,65 to 1 which is not due to alchoolic fermentation since no degradation of sucrose to ethanol was detected, b) a marked decrease or a complete inhibition of the utilization of fatty acids. On the contrary, no significant increase of R. Q. occurs, when the cotyledons are incubated in presence of 0.1M sucrose. The metabolic utilization of the fatty acids in «Cucurbita maxima» has been studied by using acetate-2-C¹⁴. Labelled acetate was fed after 30 and 90 minutes of incubation of the embryonic axes in water and, respectively in 0.1M sucrose. The radioactivity in the C0₂ and in total fatty acids fractions was measured 30 minutes after feeding the labelled acetate. It was found that: in the presence of sucrose: a) the incorporation of labelled acetate in fatty acids was increased by about 4396 after 30′ and by 10% after 90′. b) the dissimilation of acetate to CO₂ was decreased by about 5096. These results indicate that sucrose replaces lipids as respiratory material. Experiments with labelled acetate are in agreement with the hypotesis that the inhibition of lipid catabolism by sugars (or some derivative) is due chiefly an enhancement of lipid synthesis. At the same time there is probable an inhibition of fatty acids oxidation.     

Primi Dati Sulle Alghe Della Scogliera « I Travi » di Portonovo (Ancona)

Abstract

First data on the seaweeds of the reef « I Travi » of Portonovo (Ancona). — The reef « I Travi » is formed by a series of nearly vertical rock strata which from Mount « I Corvi » dip into the sea with a general direction WNW-ESE. The rock face looking towards the open sea (that is roughly to the North) is exposed to the action of the waves. The sea is particulary rough when the wind blows from the North (« Bora »), and the East (« Levante »).

The temperature of the water throughout the year varies from 9.5[ddot] C in February to 27 [ddot]C in September, that is over a range of 17.5 [ddot]C. In June the salinity of the water was of 33.6%, and the pH had a value of 8.1. Ascending and descending currents and water movements seem to mix efficiently the upper and lower waters.

The seaweed population of the rock face varies longitudinally. In the Wetsern part Acetabularia is dominant; there is a central part with prevalence of Cystoseira, and an eastern part with prevalence of Ceramium and Cladophora. Vertically one can distinguish: a Littoral Zone of 40–45 cm (maximum amplitude of the tides) with Cladophora, Enteromorpha, and other Chlorophyceae; an Infralittoral Zone with predominance of Cystoseira, Gracilaria, and, lower down of various Rhodophyceae. The Eulittoral Zone is missing.     

Sull'embriologia di Leontopodium Nivale (Ten.) Huet ex Hand. Mazz.

Abstract

Embryology of « Leontopodium nivale » (Ten.) Huet ex Hand.-Mazz. — As in « Leontopodium alpinum » Cass. var. a typicum Fiori e Paoletti, from different alpine localities, no cases of apomixis have been observed (Maugini 1962) while Sokolowska-Kulczycka (1959) has noticed this phenomenon in the same species collected on the Tatra mountains, an embryological research on « Leontopodium nivale » (Ten.) Huet ex Hand. Mazz. has been undertaken. The material, collected in the alpine garden of Campo Imperatore (Abruzzo), has shown that the development of the female gametophyte occurs as in Leontopodium alpinum, according to the normal monomegasporial type which leads to the formation of an 8-nucleate gametophyte which at maturity is almost always poliantipodate. In « Leontopodium nivale » there is no trace of apomixix, but many cases of degeneration, particularly in the mature gametophyte, have been observed.     

La Cellula: Aspetti Morfologici e Metabolici Dei Suoi Organuli

Abstract

The cell: morphologic and metabolic aspects of its organelles. — Some aspects of the mechanism of the chloroplasts movement induced by light, it has been studied in «Elodea canadensis» leaves. Red, yellow and blue light induce the movement of the chloroplasts. Green light does not promote the movement. 5.10—⁵M CMU completely inhibits cyclosis. Photosynthesis is required for cyclosis. ATP alone, does not Substitute photosynthesis, however in the presence of green light, 5.10—³M ATP, pH 6.5, promotes cyclosis movement. It has been concluded that light has dual role in promoting the movement in «Elodea» leaves: first, inducing photosynthesis and consequently the ATP production; second, light is necessary to start the movement exciting a photo-receptor, visualized like a System Controlling the induction-repression of enzymes. It has been postulated that ATP produced by illuminated chloroplasts, saturated a «SSS» system, connected with another System, «SAV», lowering the plasma viscosity; ATP in this action is not necessarily used as energetic Compound. Successively, by means an unknow photoreceptor, the mechano-enzyme-system, «SEM», promotes cyclosis utilizing ATP as energic source. The movement stop when ATP is exausted or immediately, in the presence of ATP, when the photoreceptor is not working, like happens in the dark.