176 research outputs found

    Sulla presenza di <i>Crenobia alpina</i> (Dana) (Turbellaria, Tricladida) in Sardegna

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    The presence of the stenothermic cold-water planarian Crenobia alpina (Dana) has been evidenced in Sardinia for the first time. Identification of the freshwater species was made on the basis of its physio1ogical and morpho-anatomical characteristics.Furthermore the cytological data demonstrated that this population presents a polyploid karyotype with a marked tendency to aneuploidy. The specimens were collected from three sites in the Gennargentu mountains as well as from a fourth at «Funtana Bona» near Orgosolo. The finding of Crenobia alpina in Sardinia shows that the distribution of this species extends further south within the Mediterranean area than previous reports would suggest

    Distribuzione geografica in Sardegna di planarie d'acqua dolce appartenenti alle specie <i>Dugesia</i> (S.) <i>polychroa</i> e <i>Dugesia</i> (S.) <i>mediterranea</i> (<i>Turbellaria, Tricladida</i>)

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    Geographical distribution in Sardinia of different karyological biotypes of Dugesia (Schmidtea)polychroa and Dugesia (S.) mediterranea has been investigated. On the whole, 4 biotypes of Dugesia (S.)Polychroa (A, C. D, and A pentaploid biotypes) and 2 biotypes of Dugesia (S.) mediterranea (G, and G triploid biotypes) have been recorded. The A pentaploid and G triploid biotypes were never found in Sardinia before now. We wish to underline i) the fìnding, in the Temo river, of 5 different biotypes: C, D, A pentaploid of Dugesia (S.) polychroa and G, G triploid of Dugesia (S.)mediterranea; ii) no biotypes of Dugesia (S.) polychroa or Dugesia (S.)mediterranea, up to date, have been found by us in the oriental catchment areas of Sardinia

    Rinvenimento di una Planaria ascrivibile a <i>Dugesia etrusca monoadenodactyla</i> Lepori (Turbellaria, Tricladida) nell'Isola di Molara (Sardegna)

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    The Molara planarian belonging to the group gonocephala should not be ascribed to the Dugesia benazzii of Sardinia and Corsica, but to Dugesia etrusca monoadenodactyla found in the province of Grosseto and described by Lepori in 1947. It was established that the Molara planarian belongs to the above-mentioned race by histological examination of the copulatory system as well as on the basis of its chromosome equipment which is of the 2n=16; n=8 type

    Primi dati sulla distribuzione geografica di planarie del gruppo <i>Dugesia lugubris-polychroa</i> (Turbellaria, Tricladida) in Sardegna, con particolare riguardo alla presenza di una mutazione tetraploide nel fiume Cixerri (Siliqua, Cagliari)

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    The finding of a Planarian of the Dugesia lugubris-polychroa group characterized by a tetraploid chromosome set of 4n=16; n=4 is reported. This is therefore a tetraploid mutation that has never been reported before in Sardinia. Besides mitotic metaphase plates with 16 chromosomes, which are by far the most frequent (78% of the counts), others containing fewer chromosomes, believed to be derived from segregational mitoses, were also observed

    Popolamento planariologico dei fiumi del nord Sardegna: 2. I cariotipi dei tridadi d'acqua dolce rinvenuti nel bacino idrografico del fiume Coghinas

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    Karyological and karyometric analyses were carried out on freshwater Triclad populations collected in 19 sites of the Coghinas catchment basin (North Sardinia), in order to identify the existing karyotypes and to establish their distribution. By samples collected 25 strains of the gonocephala group and 9 of the lugubris-polychroa group were obtained, on the basis of morphological and reproductive (sexual/fissiparous) caracteristics of the specimens. Within the gonocephala group 177 specimens (168 sexual and 9 fissiparous) were examined and 4 karyotypes were found as follow: l) diploid karyotype with 2n=2x= 14 belonging to Dugesia hepta species; 2) diploid 2n=2x=16, triploid 2n=3x=24 and aneuploid 2n=?x=32 karyotypes belonging to Dugesia benazzii species. The karyotype with 32 chromosomes, typical of both fissiparous and sexual specimens, is difficult to interpretate owing to the variations in chromosome morphology. All the karyotypes resulted variously coexisting and distributed. Within the lugubris-polychroa group 71 specimens were examined; 2 karyotypes were identified both diploid with 2n=2x=8 respectively belonging to Dugesia mediterranea and Dugesia polychroa species

    Popolamento planariologico dei fiumi del nord Sardegna: 1. I cariotipi delle planarie d'acqua dolce del gruppo <i>Dugesia gonocephala</i> (Tubellaria, Tricladida) presenti nel fiume Silis (Sassari)

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    Karyological investigations were carried out on tail regenerative blastemata of 104 (95 sexual and 9 fissiparous) out of 270 freshwater planarians belonging to the Dugesia gonocephala group collected at five different sites along the Silis river (North Sardinia). The results revealed that the Silis Dugesia gonocephala s.l. is made up of different karyotypes: (1) diploid karyotype with 14 chromosomes identified as Dugesia hepta; (2) diploid karyotype with 16 chromosomes and (3) triploid karyotype with 24 chromosomes, both attributable respectively to the amphimittic diploid and gynogenetic triplo-exaploid biotypes of Dugesia benazzii Lepori; (4) karyotype with 22 chromosomes; (5) karyotype with 32 chromosomes and (6) karyotype with 27 + B chromosomes of fissiparous individuals. The basic haploid set from which the last three types could have derived could not be determined since, although the chromosome number of sets was essentially constant, the composition varied considerably not only between individuals but al so within the same individual

    Descrizione di una nuova razza morfologica di <i>Dugesia (Schmidtea) polychroa (Turbellaria, Tricladida)</i> della Sardegna

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    A planarian of the Dugesia lugubris-polychroa group, characterized by triangular head, is reported from Sardinia. The apical position of the eyes is similar to the one found in Dugesia (Schmidtea) polychroa. The chromosome set, even if with slight differences, is related to the aforesaid species. Histologieal examination demonstrated its copulatory system to be different, in any detail, from those of the three species of lugubris polychroa group. The Authors believe that, on the basis of the peeuliarity of both the morphological characters and the chromosome set, the above planarian is to be temporarily considered as a new race of the Dugesia (Schimidtea) polychroa species. The denomination they suggest is Dugesia (Schmidtea) polychroa macroauriculata

    <i>Dugesia hepta</i>, nuova specie di Planaria di acqua dolce di Sardegna appartenente alla superspecie <i>Dugesia gonocephala</i> (Dugès) (Turbellaria, Tricladida)

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    A planarian belonging to the group Dugesia gonocephala s.l. was found in thirteen sites in Sardinia (eleven in the catchment area of the Rio Mannu of Porto Torres and two in that of the Coghinas). It is morphologically related to Dugesia benazzii Lepori of Sardinia and Corsica but presents a different caryotype: 2n=14; n=7 chromosomes instead of 2n=16; n=8 chromosomes. The latter is considered to be the most common in the superspecies Dugesia gonocephala of central European and Mediterranean distribution areas. On the grounds of the genomic differences made evident and its particular distribution in Sardinia, the authors believe that the planarian in question should be considered a distinet species within the group Dugesia gollocephala s.l. and propose the denomination Dugesia hepta n. sp

    Valorizzazione tecnologica di specie da frutto tipiche dell'ambiente mediterraneo

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    Technological exploitation of Sardinian tree fruit biodiversity could be a valid mean to relaunch a strategic division, which is now in a weak position. The present work deals with two studies, which are included in a more detailed Interreg II research project aimed to maximise storage and processing technologies of tree fruits of local cultivars. La valorizzazione tecnologica della biodiversità frutticola della Sardegna potrebbe costituire un sicuro mezzo di rilancio di un comparto strategico, ma al momento privo di vigore. Nel presente lavoro sono riportati due esempi di sperimentazione, nell'ambito di un più ampio ventaglio di ricerche, relative ad un progetto Interreg II, riguardanti l'ottimizzazione delle tecnologie di conservazione e trasformazione di frutti di varietà locali

    Variazione dei flavonoidi glicosilati e dell'acido ascorbico durante la conservazione di agrumi minimamente trasformati

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    Fruits and vegetables are subjected to processing and storage prior to consumption, thus leading to nutritional changes. Minimally processed citrus derivatives are noteworthy because of their high nutritional value and antioxidant properties. Therefore, the variability of ascorbic acid and flavonoids, responsible for the antioxidant capacity of citrus fruits, was studied after minimal processing and during storage. Diversi prodotti ortofrutticoli sono sottoposti, prima del consumo, ad operazioni di trasformazione e conservazione che possono portare a variazioni di carattere nutrizionale. Sicuramente degni di nota, sia in prospettiva di sviluppo futuro, sia perché già diffusi, sono i derivati degli agrumi ottenuti con minimi interventi tccnologici (segmenti, succhi freschi). Tali prodotti si caratterizzano dal punto di vista nutrizionale specialmente per il loro contenuto in acido ascorbico e flavonoidi glicosilati, responsabili pressoché in toto delle proprietà antiossidanti dell'alimento. Data la particolare importanza, pertanto, è stato verificato il destino di tali frazioni in seguito alla preparazione minima ed alla conservazione
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