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.     

Effetto del Prodotto Brachizzante “AMO-1618” sulla Crescita e sul Contenuto in Alcaloidi di Datura Stramonium L.

Abstract

The influence of the growth retarding chemical « AMO-1618 » on the growth and alkaloid content in DATURA STRAMONIUM L. — AMO-1618 (4-hydroxy-5-isopropyl-2-methylphenyl trimethylammonium chloride, 1-piperidine carboxylate) in concentration of 100 and 500 p.p.m. was applied as an aqueous spray, every day for a fortnight period, to the leaves and tops of Datura stramonium L.

The treated plants showed a reduction in growth only at the beginning, they looked, however, expecially the ones receiving the treatment with the highest concentration of the compound, more compact, sturdier and with leaves darker green and more thickened than the control. The plants were harvested four weeks following treatment. Fresh and dry weight data of leaves and roots indicated no significant change in stramonium plants treated with 100 p.p.m., while the ones treated with 500 p.p.m. showed an appreciable increase in leaves weights accompanied by a decrease in roots weights.

No significant difference, between treated and untreated plants, was observed in the concentration of total alkaloids in the leaves and in the roots.     

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.     

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.     

“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).     

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.     

Effetti Morfologici,Anatomici Ed Ultrastrutturali Indotti Dai Ritardanti Di Crescita Su Plantule Di Pisum Sativum L. Var. « Gloria Di Quimper » Cultivate in Soluzione Nutritizia

Abstract

The effect of the growth retardants on the structure of Pea seedlings coltured in nutritive solution. – The addition of CCC (2-Chloro-ethyltrimethyl ammonium chloride) and AMO 1618 (4-Hydroxyl-5-isopropyl-2 methyl-phenyl-trimethylammonium chloride. 1-piperidine carboxylate) to Pea seedlings (Pisum sativum L. var. Gloria di Quimper) promotes the usual modifications induced by growth retardants on higher plants. CCC appears less effective than AMO 1618; CCC inhibits growth only at 10²-M. concentration, on the contrary 5×10-⁵M. AMO 1618 inhibits strongly the growth of the seedlings both in the light and in darkness. CCC and AMO 1618 operate similarly as far as the inhibition of expansion growth, the increase of the stem diameter, and the decrease of the apical dominance are concerned. 10-²M. CCC stimulates both the growth of roots and the secondary roots formation, on the contrary 2,5×10-⁴M. AMO 1618 inhibits strongly the growth of the roots. AMO 1618 affects more strongly than CCC the expantion growth of the leaves. Leaves of the AMO 1618 treated plants are greener than the control plants. Plants treated with CCC and AMO 1618 are smaller because these chemicals inhibit the expantion growth of the cells. The increase of the stem diameter induced by CCC and AMO 1618 is due to the stimulation of the mitotic activity of the cambium. AMO and CCC induce a decrease of the size of the vessels and the sieve tubes. In the sieve tubes of the treated plants and slime plugs appear near to the sieve plates many slime bodies. AMO and CCC did not affect the mitotic activity of the apical meristems; in fact the plants grown in the presence of the growth retardants, show a normal primary body. AMO and CCC delay the lignification process. Chloroplasts of this Pisum sativum variety show prolamellary bodies associated to a good lamellar system. Starch granules are always present. Starch was never found in the chloroplasts of the treated plants. The general picture of the effects induced by growth retardants in Pea seedlings show so many modifications that it is very difficult to believe, like some Authors suggest, that all the effects produced by growth retardants are due to the inhibition of gibberellin biosynthesis.     

Tubular and Fibrillar Components in the Phloem of Brassica Chinensis L. Leaves

Abstract

Electron microscopical observations of the phloem of Brassica chinensis L. leaves, healthy or infected by turnip yellow mosaic virus, have shown that the «slime», characteristic proteic component of the sieve cell protoplast, is present as tubules or fibrils, free in the cellular cytoplasm or localized in the cisternae of the endoplasmic reticulum. In this paper it was thought to follow the ontogensis and evolution of the «slime» in parallel with the differentiation of the sieve tube and at the same time to contribute to the solution of the problem concerning the origin and probable function of this proteic material.     

Contributo alla Conoscenza dell'idratazione e della Pressione Osmotica Nelle Specie di Tre Associazioni Forestali delle Marche: I° - L'idratazione

Abstract

Researches on the water content and osmotic pressure in plants of three forest associations in the Marche. I° - The water content. — The main forest associations of the Umbro-Marchigiani Appennines are the Orneto-Quercetum ilicis, the Quercetum pubescentis (s. l.) and the Fagetum. In each of these associations a typical station has been chosen where the most important species have been followed from March to November 1963 in order to determine the seasonal variations of their water content (« T.I. »)expressed as percentage of fresh weight.

The annual curves show that the water content reaches very high levels in the early stages of plant development while it falls to lower levels later in the season when the leaves are full grown. The water content of each species follows a different course and can be considered a specific character. Taking into account the maximum and minimum levels of water content of the three groups of species a « hydric spectrum » has been worked out for the three associations.

The water content of each species has also been calculated as percentage of dry weight (imbibition percentage: « G.I. »).     

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.     

Ricerche Embriologiche Sul Genere Thalictrum. II. Embriologia e Cariologia Di Thalictrum Lucidum L. e di Thalictrum Minus L. Subsp. Minus

Abstract

Embryological researches in the «Thalictrum» genus. II. Embryology and caryology of «Thalictrum lucidum» L. and «Thalictrum minus» L. ssp. «minus». — In their development the female gametophytes of Thalictrum lucidum L. and Thalictrum minus L. ssp. minus follow the Normal type. In the female gametophytes of these species several types of antipodal cells occurs such as: their considerable enlargement, formation of many antipodals polyploid or polinucleated antipodal cells. In these various types, however, a rapid regression of the antipodals occurs. In T. lucidum some tendency to a disposition of the tetrapolarized type has been verified. The chromosome number has been confirmed to ben 2n=28 in besides, in the pollen development, many cases of regression of the microspores has been verified. The chromosome number has been confirmed to ben 2n=28 in Thalictrum lucidum L., and has been found to ben 2n=14 in Thalictrum minus L. ssp. minus, a new number in this species, which was earlier reported to have 2n=42.     

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 ».     

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.     

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.     

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.     

Frequenza di cellule con « DNA puffs » nel sospensore di Phaseolus coccineus in momenti diversi dello sviluppo embrionale

Abstract

Morphological aspects of Phaseolus coccineus suspensor cells at different periods of embryo development. — Embryo suspensor cells of Phaseolus coccineus have been analysed at different periods of seed and embryo development in field-grown plants and the frequency of cells involved in « DNA puffs » formation has been determined. The collected data show that: a) the relation between seed development and embryo development is not constant at different times in the season (from July to November); b) the frequency of cells showing « DNA puffs » is influenced by the above ratio. This fact seems to indicate that embryos of comparable developmental stages (as estimated by cotyledon length) show different metabolic patterns in relation to seed development and enviromental factors.     

Ricerche Sulla Vegetazione Della Valsesia. VII. Notholaena Marantae (L.) Desv. in Valsesia

Abstract

Researches on the vegetation of Valsesia. VII. «Notholaena marantae» (L.) Desv. in the Sesia Valley. — It's hereby described a station of Notholaena marantae (L.) Desv. near «Giavina Rossa» (Valsesia-Piedmont, Italy). This is probably the only place in the whole valley. The fern grows in a kind of ground formed by peridotitic rocks and on a little dry wall supporting the debris. The fern presence in a wooden valley, and under an oceanic climate could be a very interesting subject for hystorical geobotanic researches.     

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.     

Fenomeni citologici nuovi nella embriogenesi (“semigamia„) e nella microsporogenesi (“doppio nucleo di restituzione„) di rudbeckia laciniata L.

Abstract

L' A. descrive in Rudbeckia laciniata L. una specie apomittica, con gametofito femminile diploide originato da quattro divisioni del nucleo della cellula madre; di cui la prima di tipo restituzionale.

Descrive il fenomeno della «semigamia», per cui lo spermio penetra nella cellula uovo diploide senza degenerare e senza fondersi col nucleo femminile, ma si divide insieme a questo per originare un embrione di tipo chimerico.

Analogo comportamento presenta R. speciosa Wender.

Descrive anche la formazione di granuli pollinici giganti, tetraploidi, originati dalla formazione di un nucleo di restituzione in seguito ad ognuna delle due divisioni meiotiche («doppio nucleo di restituzione» o «nucleo di birestituzione»).