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.     

Secondo Contributo Alla Conoscenza Dello Sviluppo Embriologico del Genere Centaurea L. (Asteraceae). Centaurea Horrida Bad

Summary

The Author has studied the embryological development of Centaurea horrida Bad., pure pliocenic endemisms of Sardinia and has established that:

1°) the cromosomic number of the species is: 2n = 18.

2°) the genesis of microspores is of simultaneous type;

3°) The archesporium is constituted of one cell only seldom accompanied by a basal cell;

4°) the development of the female gamethophyte is of normal type;

5°) even showing cases of degenerated antipodal cells, the species has a marked tendency to the polyantipody, sometimes also characterized by a strong hypertrophy of its cells;

6°) in the species the contemporary germination of some megaspores in the same ovule is enough frequent;

7°) there are also some cases of coesistence of some gamethophytes in their different stages of development;

8°) the phenomenon of «multiple oospheres» and of «multiple synergidae» may happen;

9°) in some ovules, near the egg-apparatus, cells of two or four nuclei may be found.

For these last ascertainments (8° and 9°) the Author makes the hypothesis that it may be probably an anomalous prolification of micropylar nuclei, or asynchronous development, for delayed germination of some micropylar megaspores producing primary stages of gamethophyte.

Moreover the Author has the opportunity to bring into evidence:

10°) a case of ovular teratology represented by the extraovular development of an adult gamethophyte very similar to those previously found by the Author himself in Petasites fragrans;

11°) frequent cases of regretion of female sexuality, founding that about the 10% of the flowers examined were functionally male. The Author has fronted the possibility of the existence, in Asteraceae, also of the type of inflorescence where «flowers are all tubulated: the marginal ones neuter, the others or hermaphrodite or hermaphrodite and male».     

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.     

The cryptopolyploidy (Jaretzky 1928: «verkappte Polyploidie»; Chiarugi 1933: «criptopoliploidia»; Melinossi 1935, 1937: «duplicazione endocromosomica»). A terminological criticism.

Abstract

In the cytological literature and text-books, the term cryptopolyploidy is mainly ignored and sometimes re-interpreted and often wrongly quoted from the point of view of historical accuracy. The paternity over this term should be ascribed to Chiarugi (1933), although Jaretzky (1928a, b), while investigating karyologically two species of the genus Bunias, B. orientalis and B. erucago, first advanced a concept of «verkappte Polyploidie» to indicate the occurrence of chromosomes of enlarged size hypothetically due to fusion of homologous members (Jaretzky's «Sammelchromosomen»). By such homologous chromosome fusion a polyploid karyotype could appear as a diploid karyotype. A pupil of Chiarugi, Roma Melinossi, reinvestigating the two species quoted by Jaretzky, Bunias orientalis and B. erucago, documented a quite different karyological state for these species, cf. Melinossi (1935, 1937), that is the presence of the same karyotype (2n=14) in both species and the occurrence of chromosome of doubled size in B. erucago. Melinossi recognized B. erucago to be the cryptopolyploid species (obviously crypto-tetraploid) and not B. orientalis as assumed by Jaretzky and reinterpreted the chromosomes of doubled size as the result of a «duplicazione endocromosomica» (MELINOSSI, 1937).

Almost contemporaneously a second pupil of Chiarugi, Fernanda Pannocchia-Laj, in a karyo-embryological investigation of some species of the genus Vinca, described the occurrence of another case of cryptopolyploidy (sense Melinossi, that is by «duplicazione endocromosomica»). Besides the minor fact that this latter author spelled the term «criptopoliploidia» also as «criptopoliploidismo», her paper is very remarkable because suggested the probable occurrence of a degree of cryptopolyploidy higher than that of Bunias (crypto-tetraploid), namely the occurrence of «… una entità criptopoliploide con valore superiore al tetraploide, probabilmente ottoploide» (cf. PANNOCCHIA-LAJ, 1938 p. 177, p. 178, Fig. 36: criptottoploide).

On the basis of the results of a comparative karyological study between Vinca minor, V. major and V. difformis, PANNOCCHIA-LAJ ascribed to V. minor the diploid karyotype «2n=46», to V. major the tetraploid karyotype «2n=92», and to V. difformis the cryptopolyploid karyotype «2n=46 (x4?)». Since PANNOCCHIA-LAJ (1938, pp. 184–185), following MELINOSSI (1937), interpreted the origin of cryptopolyploidy as a phenomenon due to «duplicazione endocromosomica», the formula «2n=46 (x4?)» clearly means occurrence of «doppia duplicazione endocromosomica» or «quadruplicazione cromosomica».

The author is personally aware that PANNOCCHIA-LAJ intentionally, for scientific prudence, avoided to include such a terms in her account.

The papers of CHIARUGI, MELINOSSI and PANNOCCHIA-LAJ have been largely ignored by the subsequent cytological literature and the term cryptopolyploidy has been variably quoted or interpreted and also reinvented (cf. HOLT in SPARROW & NAUMAN, 1974)!

From a terminological point of view, there are two sound considerations which suggest a refusal of the term cryptopolyploidy, namely:

- the prefix crypto does not qualify, it only means that such a polyploidy is «not visible» (hidden) by the methods of the observer;

- the choice of the prefix crypto is injustifiable because, the cases of cryptopolyploidy show the general morphology of the relative known polyploid species, that is they are phenotypically polyploids!

Both considerations, together, suggest the refusal of the prefix crypto and the proposal of the neoterm phenopolyploidy (phenotypic polyploidy). Necessarily, the indication of phenopolyploidy is nothing else but a provisional term waiting for a modern reinvestigation of both the crypto-tetraploid Bunias erucago and the crypto-octoploid Vinca difformis.     

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.     

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.     

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 ».     

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.     

Sporobolus Poibetii (R. et S.) Hitch. e Oenothera Sinuata L. Nella Selva di San Rossore

Summary

The author describes a Sporobolus Poiretii (R. et S.) Hitchc. and Oenothera sinuata L. stand in the «Selva» (forest) of S. Rossore (near Pisa).

Earlier reports of these two adventive and perhaps naturalized species are mentioned.

The author discussues the critical and complex sistematic definition, nomenclature and sinonimy of Sporobolus Poiretii in connection with the nearly related species Sporobolus indicus R. Br.

The author prospects at the end how both Sp. Poiretii and Oe. sinuata can be inserted in the «Nuova Flora Analitica» of Italy, by Adriano Fiori.     

Stipa Trichotoma Nees nella selva di San Rossore,nuovo inquilino della flora toscaista

Summary

The Author discovers and describes a new station of Stipa trichotoma Ness (Nassella trichotoma Hackel) in the «Selva di S. Rossore » (Pisa), where it represents an adventitious and probably newly naturalized species for the Tuscan Flora.

The Author refers on the preceedind foundings of this south-American plant in Italy, discussing the complicated sinonimy, and points out the opportunity for the constitution of-a new section Nassellopsis and the interest to include the species in the new edition of «Nuova Flora Analitica d'ltalia» of Adriano Fiori.     

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.     

Phagnalon Metlesicsii Nova Sp. Aus Westsizilien,Mit Einem Überblick Über Die Gruppe Von Phagnalon Rupestre Im Mittelmeerraum

Abstract

«Phagnalon metlesicsii», a new species from Western Sicily, with a survey of the «Ph. rupestre» — group in the Mediterranean Region. — Phagnalon metlesicsii, a new species of the complex Ph. rupestre — Ph. graecum, is described. It is entirely glabrous and occurs in Western Sicily (M. Cofano) on vertical limestone rocks, nearly 200 mts. above the sea, in community with a flora particularly rich on endemics. The variability of the whole complex is discussed and some infraspecific taxa are proposed.     

Studio Floristico e Fitogeografico Delle Piccole Isole della Sardegna Nord-Occidentale

Summary

The author has studied the flora of the little islands of Northe-West Sardinia. In a former note he has referred on Isola Piana, in this one he refers on: Isola Rossa, Isola dei Porri, and Isola Foradada.

After having done the census of the species, notifying particularly the dominant ones and after having put in evidence the principal plant communities he kept his attention on some endemic species two of which are probable endemisms new to the science: Olea europaea L. v. latifolia (mihi) and Smilax aspera L. v. inermis (mihi), coming to the conclusion:

1°) The study should confirm the hypothesis that in the little islands may be manteined species, or ancient in regression, or recent in variation the recessive characters of which would be substracted to overcome of the dominant charaters of a largest population;

2°) The florae of the four islands, for theier geographical position are the expression of the Mediterranean half-dry climate;

3°) They present their plant communities from which springs the autonomy of the different «Ecoidi» with theier different predominance established by the equilibrium attained in them.     

Ricerche Sulla Vegetazione Dell'etruria Marittima

Summary

The dates of foundation of the oldest university botanical gardens.

The dates of foundation of the oldest Botanical Gardens in Italy are not well known to the greatest part of the students of Botanical History.

Also today Ms. A. Guillaumin in his « Histoire de la Botanique en France (Paris, 1954) pag. 188» writes it was « Serenissima Repubblica Veneta » who founded the first Botanical Garden in 1533, whilst in that year only the chair of Bonafede had been constituded and the foundation of the Botanical Garden in Padoa happened later in 1545.

Really the most ancient Botanical Garden in the world is not that of Padoa, but that of Pisa.

Recently in the « Archivio di Stato » of Florence has been discovered by Fedeli a letter dated July 4 th 1545 written by Luca Ghini. From it it is clear that already a month before that date Luca Ghini was collecting plants to be coultivated in the academic garden of Pisa « for utility of students ».

The critical analysis of many papers by Luigi Anguillara allowe us to establish that Luca Ghini with the same Anguillara collected plants in the surreoundings of Pisa and on the Apuane Alps, from 1543 to 1544, and planted them in the academic garden of Pisa, which therefore must be considered the first Botanical Garden in the world, founded in the Summer 1543.

The second Botanical Garden in order of time is that of Padoa having been established by the « Senato Veneto » in 1545 and actually founded on July 7 th 1545 (de Visiani). The first director of Botanical Garden of Padoa was Luigi Anguillara after having left Pisa where he cooperated with Luca Ghini to found the Botanical Garden of Pisa.

Finally the third Botanical Garden is that of Florence (« Giardino dei Semplici ») founded as a dependance of that of Pisa by Luca Ghini, for school utility during the holyday, when the Florentine students remained at home. The date of its founding is December 1st 1545, as it appears from an an attorney document dated November 16th 1545 preserved in the « Archivio di Stato » of Florence (Volpi).

In conclusion the right chronology of the oldest University Botanical Gardens in the world is as follows:

1st: Pisa, Summer 1543

2nd: Padoa, July 7th 1545

3rd: Florence, December 1st 1545.     

Attività Fotosintetica di Alghe Marine Nella Grotta Delle Viole (Isola S. Domino - Tremiti)

Abstract

Photosynthetic rates of some algae in the marine cave « Grotta delle Viole » (Is. S. Domino - Tremiti). — The « Grotta delle Viole » is one of the several marine caves located along the calcareous rocky southern littoral of the Island S. Domino (Tremiti) in the Adriatic Sea. Morphologically this cave is a tunnel, which connects the open littoral sea with a little bay. Availing of these environmental factors, we have chosen three stations to measure the photosyn-thetic yield, under completely natural conditions, of algae particularly important for some marine communities, described in an other paper (see, Pignatti S. et al. 1967). In station 1 (fig. 1) we have a biotope with strongly reduced light and in the neighbouring stations 2 and 3, two biotopes exposed to sun-light. We have studied three species living in dark places (« Peyssonelia » cfr. « harveyana », « Palmophyllum crassum » and « Pseudolithophyllum expansum » two of well lighted habitas (« Padina pavonia » and « Dictyota dichotoma » and one of intermediate place (« Codium difforme ») Some information on the optical conditions of the seawater have been obtained with a photoelectric cell, filters were used to measure the red and blue light penetration (Tab. 1, 2). This part of the Adriatic Sea is characterized by high penetration of blue light. In the cave this light is highly predominant. The photosynthetic rates were measured in natural conditions by determining the output in time O₂ using the Winkler method (Tab. 3) and the CO₂ changes by measuring pH-changes in short time intervals with an original method using a submarine incubation cell, of our design, equipped with the electrodes of a pH-meter and a spot-light galvanometer as measure instrument. The data obtained with the latter method have been statistically analized, their significance discussed and reported in Tab. 4. On the basis of the results, the species, which are confined in places with reduced light intensity, show a low but measurable photosynthetic surplus only in their natural habitats, transferred in high-light intensity they show a deficit. This fact can suggest the hypotheses: deactivation of the chlorophyll in green and blue light or competitive inhibition due to the presence of accessory pigments. The species of sunny habitats transferred in low-light intensity show an assimilatory deficit, that in this case, with great probability, is due to the progressive reduction of the photosynthetic process. These considerations explaine also the observed distributions of the species and of the algal communities (fig. 1), since each of them is connected with a light optimum. It seems important moreover to note that here, for the first time, data are given also on photosynthetic activity of Lithothamnia.     

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.