Uticaj osmotske dehidracije na kivi: rezultati multianalitičkog pristupa proučavanja strukture

This paper presents the results of the comparison of different analytical techniques (Differential Scanning Calorimetry - DSC, Low Field Nuclear Magnetic Resonance - LF-NMR, Light Microscopy - LM and Transmission Electron Microscopy – TEM) in order to evaluate the mass transfer, water status and cellular compartment modifications of the kiwifruit outer pericarp tissue during osmotic dehydration treatment (OD). Two kiwifruit species, A. deliciosa and A. chinensis were submitted to OD. OD was performed in a 61.5 % w/v sucrose solution at three different temperatures (25, 35 and 45 °C), with treatment time from 0 to 300 min. Peleg’s model highlighted that the main response differences between the two kiwifruit species occurred during the initial phase of the osmotic treatment. DSC parameters appeared to be sensitive to water and solid exchange between fruits and osmotic solution. LF-NMR proton T2 revealed the consequences of the water-solid exchange on the cell compartments, namely vacuole, cytoplasm plus extracellular space and cell wall. During OD, the reduction of the vacuole proton pool, detected by LF-NMR, suggested a shrinkage of such compartment, confirmed by LM. Cell walls of outer pericarp showed considerable changes in size, structure and stain uptake during OD observed at TEM. The proposed multianalytical approaches should enable better design of combined processing technologies permitting the evaluation of their effects on tissue response.U ovom radu su prikazani rezultati poređenja različitih analitičkih tehnika (Diferencijalna skeniranja Kalorimetrija – DSC, Niska Polje nuklearna magnetna rezonanca - LF-NMR, svetlost mikroskopije - LM i Prenos elektronsku mikroskopiju - TEM), u cilju određivanja prenosa mase, statusa vode i modifikacije ćelija tkiva perikarpa kivija tokom osmotske dehidratacije tretmana (OD). Dve sorte kivija su bile izložene osmotskom tretmanu, A. deliciosa i A. chinensis. Osmotsko sušenje obavljeno je u 61,5% rastvoru saharoze na tri različite temperature (25, 35 i 45°C), sa vremenom trajanja sušenja od 0 do 300 minuta. Pelegovim modelom naglašene su glavne razlike između dve sorte kivija koje se događaju tokom početne faze osmotskog tretmana. DSC parametri osetljivi su na izmenu vode i čvrste materije između voća i osmotskog rastvora. LF-NMR-om otkrivene su posledice razmene vode i čvrste materije na ćeliju, odnosno vakuole, citoplazmu sa vanćelijskim prostorom i ćelijski zid. Tokom OD, smanjenje vakuole protona bazena, otkrivena je LF-NMR, predložio skupljanja takvog odeljka, potvrđeno LM. Ćelijske zidove spoljne perikarpa su pokazali značajne promene u veličini, strukturi i mrlja uzimanja u toku OD posmatrano na sistem. Predloženi multianalitical pristupi treba da omogući bolji dizajn u kombinaciji obrade tehnologija dozvoljava procenu njihovog uticaja na tkivo odgovor.Fil: Dalla Rosa, Marco. Università di Bologna; ItaliaFil: Tylewicz, Urszula. Università di Bologna; ItaliaFil: Panarese, Valentina. Università di Bologna; ItaliaFil: Laghi, Luca. Università di Bologna; ItaliaFil: Pisi, Annamaria. Università di Bologna; ItaliaFil: Santagapita, Patricio Roman. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rocculi, Pietro. Università di Bologna; Itali

SEM Investigation about Hyphal Relationships between Some Antagonistic Fungi against «Fusarium» spp. Foot Rot Pathogen of Wheat

Wheat foot rot caused by Fusarium species is a worldwide wheat disease against which the use of biocontrol agents is of increasing interest. Mycoparasitic activities of a strain of five antagonistic fungi, Gliocladium roseum (GR11), Penicillium frequentans (PF), Trichoderma atroviride (TA312), T. longibrachiatum (TL9) and T. harzianum (TH144), against three pathogens, Fusarium culmorum, F. graminearum and F. nivale, were studied by scanning electron microscopy (SEM). SEM observations suggested that the outcome of interaction between antagonist and pathogen occurred when intimate contact was established between hyphae triggering a series of events in pathogen degradation. The interaction between Trichoderma spp. and Fusarium spp. revealed that the mycoparasitic hyphae were usually attached longitudinally to the hyphae of the pathogens; hyphal coilings, hooks, pincer-shaped structures, short contact branches and hyphal depressions were also present. GR11 and PF hyphae grew mainly parallel to the pathogen causing its hyphal depression. The parasitic action of the antagonists shown with the formation of pincers, hooks and other structures leading to cell disruption, goes some way towards explaining their mode of action in the biological control of the pathogens studied

Survey of the main causal agents of fusarium head blight of durum wheat around Bologna, northern Italy

Several Fusarium species and Microdochium nivale are involved in fusarium head blight (FHB), which in Italy has been constantly present on wheat since 1995. This study was carried out from 1995 to 2007 on FHB-infected durum wheat heads collected in the Bologna countryside, Emilia-Romagna, northern Italy. The most frequent Fusarium species found were: Fusarium graminearum (32.1%), F. culmorum (25.2%) and F. poae (17.8%), while F. avenaceum and M. nivale occurred discontinuously. Other Fusarium species were also found, but only sporadically. It is important to identify and characterize the main species involved in the FHB syndrome for this will help us to establish control strategies that will contain the disease and the content of mycotoxins in food and animal feed

In vitro effects of tea tree oil (Melaleuca alternifolia essential oil) and its principal component terpinen-4-ol on swine spermatozoa

The growing interest towards essential oils stems from their biological capabilities that include antibacterial and antioxidant effects. Such properties may be extremely useful in the reproductive field; nonetheless essential oils show toxic effects that can lead to cell disruption. The present study aimed to evaluate and compare the effects of tea tree oil (TTO) and its principal component terpinen-4-ol (TER) on the morpho-functional parameters of swine spermatozoa. Experimental samples were prepared by suspending 15 7 10 7 spermatozoa in 5 mL of medium with different concentrations of the above-mentioned compounds: from 0.2 to 2 mg/mL at an interval of 0.2 for TTO, while TER concentrations were adjusted according to its presence in TTO (41.5%). After 3 h incubation at 16 \u25e6 C, samples were analyzed for pH, viability, acrosome status, and objective motility. The results highlighted a concentration-dependent effect of TTO with total motility as the most sensitive parameter. TER was better tolerated, and the most sensitive parameters were related to membrane integrity, suggesting a different pattern of interaction. The study confirms the importance of evaluating the effects of natural compounds on spermatozoa before exploiting their beneficial effects. Spermatozoa seem to be good candidates for preliminary toxicological screenings in the light of their peculiar properties

Morphological modifications in wheat seedlings infected by Fusarium culmorum examined at SEM

Fusarium culmorum is one of the most important pathogens of winter cereals in Italy and is typical of cereals grown in dry soils of temperate areas throughout the world. The fungus causes a range of diseases such as seedling blight, brown foot rot and ear blight. When tissue portions from the crown areas of durum wheat seedlings, at decimal growth stage (GS) 13, grown in F. culmorum inoculated compost were examined at the scanning electron microscope (SEM), they showed a damaged epidermal cell layer that exposed the parenchyma which was characterised by high cell proliferation, with widely spaced, irregularly shaped and loosely arranged cells. No damage was observed at root level

Preliminary work for full -lenght CDNA clones construction of Italian Soil-borne cereal mosaic virus isolate

A mosaic disease of winter wheat was first described in the USA in 1919 and later was world wide associated to the Furovirus Soil-borne wheat mosaic virus (SBWMV), transmitted by the soil-borne plasmodiophorid Polymyxa graminis. Subsequent sequence analyises divided American, European and Chinese isolates into different species within the Furovirus genus: wheat mosaic disease is generally caused by the species SBWMV in the United States, Brazil and Canada, Soil-borne cereal mosaic virus (SBCMV ) in Europe and Chinese wheat mosaic virus (CWMV) in Asia. In Italy, SBCMV was first reported in 1960 on cultivars of common wheat (Triticum aestivum) grown in the Po valley, and subsequently also on durum wheat (Triticum durum) in the central and southern Italian regions. SBCMV has been shown to cause grain yield reductions of about 50-70% on the most susceptible varieties in Italy. The use of resistant varieties, due to the persistent nature of the virus within the soil, is the only practical and economical viable mean of control. The SBWMV, SBCMV and CWMV genomes consist of two plus-sense strands of RNA. RNA1 (about 7 kb) contains three open reading frames which encode for the RNA polymerase, the methyltransferase-helicase and the cell-to-cell movement proteins, The RNA2 (about 3.7 kb) encodes for the coat protein, for protein involved on lasmodiophorid transmission of the virus, pathogenicity determinant, suppressor of RNA silencing and for 25 kDa protein with unknown function. An Italian isolate of SBCMV has been derived from infected wheat plants collected in a field near Bologna in 2007. Instability of a viral cDNA insert in a bacterial plasmid vector has been previously reported with a number of plus-sense RNA viruses in the process of construction of full-length cDNA clones. Several approaches have been examined as a solution for this problem with the aim to produce cDNA clones of the complete SBCMV genome. Strategies based on the use of several plasmid vectors with different markers and high- or low-copy numbers, cDNA insertion in both orientations in the plasmid, insertion of multiple introns into a full-length cDNA, use of E. coli and Bacillus subtilis strains with different phenotypes have been employed in attempting the construction of the full-length SBCMV RNA-1 cDNA clone. Two clones, containing the 5’-terminal 3.9-kb region and the 3’-terminal 3.1-kb region, have been produced and a full-length form can be reconstituted from them. Plasmid containing SBCMV RNA-2 cDNA has been obtained cloning full-length PCR product. Biological activity of the clones has been tested by rub-inoculation on Chenopodium quinoa and T. durum plants of the in vitro transcripts produced from plasmids