Sulla cariologia del Genere Carlina L.

Riassunto

L'A. ha studiato i cariogrammi di 6 specie italiane del genere Carlina L. (C. gummifera Less. var. Fontanesii (DC.) Fiori, C. acaulis L. var. alpina (Jacq.) Fiori, C. acanthifolia All., C. lanata L., C. vulgaris L., C. carymbosa L.).

Il corredo cromosomico è 2n = 20 per tutte le specie. Per la presenza di un gruppo di cromosomi della lunghezza superiore a 4 μ nelle specie a grossi capolini, si rende possibile distinguere auche cariologicamente nel genere Carlina L. due sezioni, corrispondenti alla possibile distinzione morfologica delle Carline in Macrocefale (C. gummifera Less. var. Fontanesii (DC) Fiori, C. acaulis L. var. alpina (Jacq.) Fiori, C. acanthifolia All., C. latana L.) e Microcefale (C. vulgaris L. e C. eorymbosa L.).     

Osservazioni Sulla Maggiorana (Origanum Majorana L.) in Veste di Pianta Coltivata

Abstract

Stomatal features and ontogeny of stomata of 11 ornamental taxa of monocotyledonous families with Agavaceae (1 species), Amaryllidaceae (1 species), Araceae (3 species), Cannaceae (1 species), Commelinaceae (3 species), Liliaceae (1 species), and Musaceae (1 species) have been studied. Features like stomatal area, leaf area occupied by stomata and per cent leaf area occupied by stomata are reported for these taxa for the first time.     

Ricerche Sulla Biologia e Le Caratteristiche Zimogene di Saccharomyces Heterogenicus Oster W.

Summary

The Author, in the study of the apple microflora, had the occasion of often isolating Saccharomyces heterogenicus, which had been isolated and formerly described by Osterwalder.

More careful morphological and physiological researches were completed because species worthy of a better illustration was in question, for the importance too it could have in the apple juices fermentation, in consideration of the manifacture of ciders.

The results of the work herein reported, explain some morfo-physiological views of a naturalistic interest and let us infer as to technological views, that Sacch. heterogenicus can find an useful employ for its high zymogen activity, in preparing ciders which are up to these days normally intrusted to the spontaneous fermentation.     

Ecological differentiation and cladogenesis of Baldellia (L.) Parl. (Alismataceae)

The Iberian Peninsula is home to a large number of endemic species that often show strong genetic subdivisions which indicate possible isolation of populations in the past. Numerous phylogeographic and phylogenetic studies on Iberian flora and fauna have revealed this territory to be the origin of genetic differentiation during the Pleistocene Ice Age. To better understand the influence of Plio-Pleistocene climatic oscillations on the cladogenesis and population structuring of refugial taxa restricted to freshwaters of the Iberian Peninsula, we studied the evolutionary history of the small European genus Baldellia, both from a phylogenetic/phylogeographic perspective and regarding its ecological characteristics. Molecular analyses were based on four plastid regions and nuclear ITS2 ribosomal spacer from individuals belonging to geographically isolated Baldellia populations, while the relationships between climate and Baldellia species distribution was investigated by redundancy analysis applied to the climatic data with the occurrence of Baldellia species as external variables. The absence of a clear phylogenetic signal most likely reflects a common and recent cladogenesis for Baldellia. In contrast, the more rapidly evolving plastid sequences indicate a recent phylogeographic history of refugial repartition and ecological segregation probably occurring during the last glaciation, a scenario well supported by marked differences in species?? ecological preferences and climate analysis.     

Structure of Vessels and Tracheids of Regnellidium diphyllum Lindman (Marsileaceae)

The occurrence of vessels in the root of Regnellidium diphyllumis reported and tracheids with helical and reticulate thickeningson their walls are described. The vessels in the root are helically-thickenedand they seem to have originated from helically-thickened tracheidslike the vessel members of the primary xylem of angiosperms.In the rhizome and petiole, branched tracheids are of commonoccurrence.     

Sulla penetrazione di Penicillium digitatum Sacc. e Penicillium italicum Wehmer nei frutti degli agrumi

Summary

The A., with a series of controls and investigations, accomplished on different groups of Oranges and following various forms of artificial infection with Penicillium digitatum and Penicillium italicum, renders evident the different reactions that these moulds have with regard to the resistance of the cuticle and the epidermic and under-epidermic stratums of the peel of the controlled fruits. Moreover the A. confirms that both the P. digitatum and the P. italicum can act as «parasite of injury» and as «parasite of contact».     

Salt Secretion in Aeluropus litoralis (Willd.) Parl.

The effect of ion composition and concentration in the rootmedium on salt secretion by Aeluropus litoralis was investigated.The presence of a high ionic concentration in the medium stimulatedthe secretion process. The sodium concentration in the secretedfluid was found to be always higher than its concentration inthe medium. A positive correlation was found between the outersodium chloride concentration and the amount of sodium secretedand/or leaf contents. Sodium secretion exhibited a high efficiencyin excluding excess sodium from leaftissues. Sodium retentionin the leaves occurred in relatively low rates. The secretion mechanisms were found to be highly selective tosodium, opposing potassium and calcium. In contrast, potassiumand calcium were retained in the leaves to a greater degreethan sodium. Antagonistic relationships between sodium and potassiumand sodium and calcium were observed in secretion. The secreted fluid contains also various organic substances.Several interpretations to the results in connection with theproposed hypotheses to the mechanism of salt secretion werediscussed.     

Alcune Osservazioni Sulla Divisione Cellulare in Oedogonium (con Tavv. VIII-IX)

Riassunto

L'A. prende in considerazione il comportamento del cercine mucillagginoso e del nucleolo durante la divisione cellulare in Oedogonium e prospetta l'ipotesi che il nucleolo sia in relazione con la formazione della membrana trasversale.