Azione della luce sulla crescita allo stadio di plantula di un mutante clorofilliano di Triticum durum Desf

Abstract

ACTION OF LIGHT ON SEEDLING GROWTH IN A YELLOW-GREEN MUTANT OF TRITICUM DURUM DESF. — Dry grains of Triticum durum cv. « Cappelli » and its radiation-induced yellow-green mutant were sown in sand in four environment, different for light conditions (daylight, artificial light, ultraviolet rays, darkness), having all the same temperature (23°C.). Seven days after sowing, the following data were registered: a) growth (in cm.) of the shoot and of the longest root; b) fresh weight (in gr.) of shoots and roots; c) water content of shoots and roots.

The following main results were obtained:

1. the yellow-green mutant always shows less growth and less weight increase than normal « Cappelli », with the exception of the seedlings grown at daylight, which have shorter shoots and longer roots than the normal « Cappelli » but the same weight:

2. artificial light, besides depressing the growth of the roots of the yellow-green mutant, which becomes green under these conditions, induces a remarkable decrease in the water content of the roots of the two wheats.

     

Primi Dati Sull'andamento Stagionale delle Temperature del Troneo di Olivo

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: 1^rst in the air, hanging from the stem, m. 1,30, high; 2^nd into the outer bark, cm, 0,5 deep; 3^rd into the cambium, cm. 1,5 deep; 4^th into the sap-wood, cm. 6 deep; 5^th 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.     

Importanti modificazioni morfologiche di un Melo selvatico

Riassunto

Si descrivono modificazioni morfologiche e anatomiche di un melo (Pirus Malus) cresciuto su una montagna del Sannio (Montagnola di Civitanova) in un ambiente molto sfavorevole per gli eccessi o difetti di temperature. Si premette una descrizione anatomica del fusto e in seguito si trattano vari casi di cicatrizzazione di ferite semplici e complesse. In ultimo si esaminano alcune saldature naturali di rametti e concrescimenti che sono molto frequenti e morfologicamente importanti.

Gli agenti che hanno provocato queste strutture anomali del melo sia sulla chionia sia nello sviluppo sono: vento, fieddo, caldo, e morsicature di animali superiori, specialmente di vacche, che sulla Montagnola durante l'estate sono raccolte in numerosi greggi.     

Localizzazione intracellulare della clorogenico ossidasi in tessuti di tubero di patata in fase di attivazione

Abstract

INTRACELLULAR LOCALIZATION OF CHLOROGENIC ACID OXIDASE IN AGED POTATO TUBER DISCS. — The localization in the cells of chlorogenic acid oxidase has been investigated in potato tubers and discs of potato tuber. It has been ascertained that the rise of activity per gram of tissue, after preparation of discs, is not due to bacterial or fungal growth. The activity is widely distributed among cell fractions. Some activity is found in mitochondria, while most of the activity is distributed among soluble fraction and a « microsomal » fraction sedimented by centrifugation in the range 15.000–50.000 x g. This fraction appears to contain mitochondrial fragments, fragments of the endoplasmic reticulum and ribosomes. When tuber discs are aged, the rise of chlorogenic acid oxidase activity is much larger in the soluble than in particulate fraction.     

Osservazioni Sull'ultrastruttura Delle Cellule Tumorali di un Ibrido Interspecifico del Genere Nicotiana

Abstract

Ultrastructural study of tumor cells of an interspecific hybrid of the genus <Nicotiana>. — The ultrastructure of tumor cells of interspecific hybrids of Nicotiana paniculata × N. langsdorffii, has been investigated. A comparative analysis between meristematic and parenchymatic cells obtained from the tumors plants of the hybrid and the controll tissues indicates that the tumor cells have an altered structure of the nuclei and of the chloroplasts and a very poor cytoplasmic content. These modifications resemble those observed in cells from plants soffering of various metabolic disturbances. A study of structural modification occurring in the necrotic areas shows that the cells undergo aspecific alterations of organelles double mambranes followed by disruption of their structure and eventually condensation of the cytoplasmic matrix.     

Monte Linas nuovo anello di congiunzione nell'areale della Scilla obtusifolia Poir

Abstract

MONTE LINAS, A NEW BRIGDE STATION IN THE SARDINIAN DISTRIBUTION OF SCILLA OBTUSIFOLIA POIR. — Two new phytocenosis of Scilla obtusifolia Poir. in Sardinia on Monte Linas have been described; their particular interest is that they connect the so far stations of this species in Sardinia. Monte Linas acts as a bridge between the southern sardinian stations and the northern ones, which have been already described by DESOLE (1959).     

Herbaceous ground cover reduces nest predation in olive groves

Capsule Bare ground increases artificial nest predation in olive groves.

Aims To assess the effect of different soil management regimes on nest predation rates in olive groves.

Methods We performed nest predation experiments with artificial nests during the breeding season in 2013, in two areas of southern Spain. Each artificial nest (n?=?300) contained three quail Coturnix eggs, two of which were unmanipulated and the third one was emptied and injected with plaster. Predators were identified by marks on eggs filled with plaster.

Results Ground nests were significantly more depredated, irrespective of the presence of ground cover; tree nests were less depredated in fields with ground cover. There was a clear difference in nest predators of ground and tree nests. Rodents were the most frequent predators of tree nests.

Conclusion Lower predation rates of tree nests in orchards with ground cover are probably linked to a change in the foraging behaviour of rodents, which in these more complex habitats might be restricted by rodents' own risk of predation. This study underscores the important role of agricultural practices in preserving farmland bird communities, particularly tree-nesting species, suggesting that for this group, implementation of ground cover in olive groves might enhance breeding success by reducing nest predation rates.     

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.     

Osservazioni carioembriologiche in Ornithogalum di Sardegna: Nota I. - Sporogenesi e sviluppo dei gametofiti in Ornithogalum caudatum Ait

Abstract

CARYOEMBRYOLOGICAL STUDIES in ORNITHOGALUM OF SARDINIA.

I. - SPOROGENESIS AND DEVELOPMENT OF THE GAMETOPHYTES IN ÒRNITHOGALUM CAUDATUM AIT. — After a concise synthesis of the caryoembryological knowledges regarding the taxa of Ornithogalum present in Sardinia, the embryology and morphology of Ornithogalum caudatum Ait., have been investigated.

In a three-locular ovary the ovules are anatropous, epitropous with nucellus crassinucellate and only one archesporial cell evolves a mother cell.

The development of the female gametophyte tallies with the Polygonum (Normal) Type.

The homoetypical division presents an asynchronous proceeding in the cellules of the dyad with a considerable delay in the two-nucleate arrangement, especially in the chalazal cell.

Antipodal cells present a hypertrophic growing, but they present no tendency to polyantipody.

The endosperm is of the Helobiae Type.

The divisions of the pollen mother-cells are of the successive Type.

Longest axis of 1-sulcate pollen grains about 76 micron.

A true tapetal periplasmodium isn't formed in the anthers.

The chromosome number is 2n = 54.

Raphides accour in the cataphylls, in the parenchymatous tissues of the leaf and in several parts of the floral region.     

Rinvenimento del polline di Keteleeria in alcuni depositi quaternari dell'Italia centro-settentrionale

Abstract

THE DISCOVERING OF THE KETELEERIA'S POLLEN-GRAIN IN SOME QUATERNARY DEPOSITS OF THE CENTRAL AND NORTHERN ITALY. — The Author observes the specy of Keteleeria with the pollen analysis executed on deposits of turfys, clays and brown coals of some Umbro-Marchigiano and of the Po Plain localyties.

The Keteleeria to-day is living only in China and Japan; in Italy it was living also during the early and middle Pleistocene.     

Osser Vazioni Anatomiche su Foglie di Olivo Sane ed Attaccate da Spilocaea Oleagina (Cast.) Hugh.

Abstract

Anatomical observations on sound leaves and by SPILOCAEA OLEAGINA (Cast.) Hug infected leaves in Olive-tree. — The author has studied the anatomical characters comparatively between two cv. of Olive tree growing in Messina district (Sicily): cv. Ogliarola, receptive to Spilocaea oleagina (Cast.) Hug, and cv. Leccino not receptive.

Anatomical differences of the leaf as a whole and particularly of the «cuticular membrane » have been observed between sound leaves and attacked leaves of cv. Ogliarola, and sound leaves of cv. Leccino.

The main conclusions drawn from this study are the following ones:

The mesophyll is thicker in cv. Ogliarola and thinner in cv. Leccino.

The cuticular membrane and its 4 layers are thicker in Ogliarola leaves than in Leccino's ones.

Ogliarola leaves attacked by the fungus show a cuticolar membrane thicker than the sound leaves of the same cultivar.

Hiperplastic and hipertrophic tissues have been observed in Ogliarola leaves attacked by Spilocaea, expecially epidermis and palisade.

The anatomical causes of resistence and receptivity are prospected.     

Rapporti Tra Assunzione D'acqua,Metabolismo e Sintesi di Enzimi Nell'endosperma Di Semi Germinanti di Ricinus Communis

Abstract

Water uptake, activation of metabolism and enzyme synthesis in germinating castor bean seeds. — During the first days of germination water uptake by the castor bean seed endosperm is accompanied by a rapid rise of respiratory activity and of the « in vitro » detectable activity of a number of enzymes. The finding that the increase of enzyme activity is strongly inibited by protein synthesis inhibitors suggests an « ex novo » synthesis of enzymes in the endosperm of the germinating seed. The present investigation on the relationship between water uptake, metabolic activity and enzyme activity level lead to the following conclusions:

I - The increase of enzyme activity is strictly dependent on the availability of water, and on the rate of water uptake. When water uptake is depressed by incubation of the seed in high osmolarity media, enzyme activation is also severely depressed.

This is also observed when the seeds are germinating in contact with an amount of water consistently lower then the one they would taken up, in a given time (24 h), under conditions of unlimeted water availability.

II - The temperature coefficient of water uptake is close to 1.5 during the first 24 h, higher than 2 in the following 3 days. Low temperature almost completely inhibits the increase of enzyme activities in the endosperm.

III - Anaerobiosis inhibits the rate of water uptake by about 50%, in the first 24 h, and almost completely, in the following 3 days. Also the rise of enzyme activities is severely inhibited by lack of oxygen. The effect of protein synthesis inhibitors on water uptake is somewhat smaller, and the one on enzyme activity is somewhat larger than that of anaerobiosis.

These results are interpreted as indicating that during the early period of germination water uptake becomes more and more dependent on the metabolic activities of the endosperm cells, in as much the latter lead to the appearance of osmotically active substances and, possibly, to changes of the cell wall properties.

On the other hand, the level of hydration of the cytoplasm represents a limiting factor for the development of the mechanism involved in enzyme synthesis and metabolic activation.     

Fenomeni di Inattivazione e di Riattivazione Enzimatica in Endospermi di semi di Ricino

Abstract

Inactivation and riactivation of enzymes in endosperms of castor bean seeds. — On the basis of previous results, the possibility has been investigated of the reversible interconversion of active and inactive form of enzymes in castor bean seeds, during their development.

The results described here indicate that:

1. the activity of some glycolytic enzymes increases greatly (81% and 400% increase of, respectively, Gl-6-P-dehydrogenase and aldolase) upon incubation of dry seeds for few hours at 4 °C.

2. The decrease of enzyme activity upon dehydration of seeds and the increase during the subsequent imbibition can be shown reproducibly.

3. This same observation is made for oxygen uptake.

These results are interpreted to indicate the reversible inactivation of enzymes caused by dehydration of seeds.     

Effetto di Popolazione tra Espianti di Helianthus Tuberosus

Abstract

Population effect among explants of jerusalem artichoke. — We found that among explants of Jerusalem artichoke cultured « in vitro » are not present positive population effects, as reported by others A.A.     

Dimostrazione ultrastrutturale di un componente parietale anomalo in Trichophyton mentagrophytes trattato con Phosfon D

Abstract

An abnormal cell wall component in Trichophyton mentagrophytes treated with Phosfon D: ultrastructural demonstration. – Phosfon D, a growth-retarding chemical in higher plants, at the concentration of 5 × 10^?4 M inhibits the development of the dermatophytic fungus Trichophyton mentagrophytes. In the treated samples the diameter of the thallus is about 50% smaller than normal. The mycostatic effect of Phosfon D is accompanied by characteristic alterations of the cell wall ultrastructure with the appearance of dense granular masses not revealable after conventional fixation, but only after employing TAPO containing fixatives.     

L'Azione Fisiologica del Nichel Sulle Piante di un Terreno Serpenitinoso

Abstract

The Author, on the basis of numerous results of pollen analysis on turfy-clayey deposits especially in Delta Padano, shows the gradual impoverishment, the main ancient species (Pinus haploxylon, Abies nordmanniana, Tsuga, Cedrus, Carya, Pterocarya, Zelkova, Castanea latifolia) suffered from during middle and upper Pleistocene.     

Fissazione di CO2 in Cuscuta epithymum

Abstract

CO₂ FIXATION IN CUSCUTA EPITHYMUM. — Seedlings of Cuscuta epithymum fixe approximately the same amount of C¹⁴O₂ irrespectively of age, pigmentation, presence or absence of light. Examination by paper chromatography of the extracts of plants exposed to C¹¹O₂ revealed that most, or all, of the radioactivity is concentrated in the area of the organic acids and of the acidic amino acids. It is tentatively concluded that C. epithymum fixes carbon dioxide through a mechanism different from that involving ribulose-1,5-diphosphate carboxylase and carboxydismutase.     

Istogenesi e caratteri anatomici dei tessuti ricavati da frammenti di germoglio di Solanum Tuberosum L. coltivati In Vitro

Abstract

HISTOGENESIS AND ANATOMICAL CHARACTERISTICS OF PORTIONS OF SOLANUM TUBEROSUM SPROUTS CULTIVATED IN VITRO. — Disks cut from sprouts of Solanum tuberosum L. have been cultured on White's basic or modified medium (White, 1943) with 20 mg/l KH2₂PO₄ 50 mg/l adenine, and 12 or 24 mg/l NAA.

Sections were prepared according to Morel's method (1948). Only on the disks cultured on White's modified medium with 12 mg/1/NAA growth glomerules and a normal meristematic layer were present, while there were no signs of cellular hypertrophy and organogenetic phenomena.

12 mg/l appears therefore to be the optimal dose of NAA for cultures of excised portions of potato sprouts. Adenine is however always necessary because it triplicates the growth activity of the tissues and because through its antagonism with regard to auxin it favours the genesis of the callus.     

Sull'evoluzione Dei Mitocondri Nell'endosperma di Semi di Ricino in Germinazione

Abstract

On the behavior of mitochondria in the castor bean seed endosperm during the early phases of germination. — In the endosperm of the castor bean seed the oxidative activity and the protein nitrogen contents of the mitochondrial fraction markedly increase during the first period of germination (Beevers and coworkers). The activation of the mitochondrial system is paralleled by a similar increase of the activity of several soluble enzymes; the latter process is severely depressed by protein synthesis inhibitors (Cornaggia, Aberghina).

The present research is aimed to understand at what extent phenomena of activation and/or, respectively, of « ex novo » synthesis are responsible of the increase of mitochondrial activity. The following aspects of the mitochondrial behavior during the early period of germination were investigated:

a) Changes in the activity of cytochrome oxydase, malate dehydrogenase and of the succinate-citochrome reductase system.

b) Changes in the morphology of mitochondria and other particulated cell structures, as revealed by electron microscopy.

In the mitochondrial preparation all of the three enzymatic activities investigated were found to increase rapidly during the first days of germination. The increase during the first 24 hours was almost as large when measured as specific activity (activity per mg protein in the mitochondrial fraction) than when measured on an absolute (i.e. per seed) basis; moreover, it was not significantly inhibited by puromycin or by actinomycin. The increase of the three activities during the following period of germination (second-third day) was accompanied by an increase of the protein nitrogen (per seed) in the mitochondrial fraction, and was consistently depressed by the protein synthesis inhibitors.

In the mitochondrial preparation all of the three enzymatic activities investigated were found to increase rapidly during the first days of germination. The increase during the first 24 hours was almost as large when measured as specific activity (activity per mg protein in the mitochondrial fraction) than when measured on an absolute (i.e. per seed) basis; moreover, it was not significantly inhibited by puromycin or by actinomycin. The increase of the three activities during the following period of germination (second-third day) was accompanied by an increase of the protein nitrogen (per seed) in the mitochondrial fraction, and was consistently depressed by the protein synthesis inhibitors.

These results, integrated with those of other investigations on the same material are in agreement with the hypothesis that the activation of metabolism in the endosperm during germination depends in a very early phase mainly on the transition of enzyme systems from an inactive to an active state; while in a second phase synthesis « ex novo » of enzymes and cell structures predominates.