482 research outputs found
The use of ligninase enzymes to target the scarification of the seed coat: application for the propagation of the orchids Himantoglossum adriaticum and Anacamptis morio.
No full textSeed dormancy may be associated with the presence of a rigid and impermeable integument that consists for the most part of lignin. Traditional methods for the scarification of the seed coat use corrosive chemicals, such as sulfuric acid or sodium hypochlorite, that can induce collateral effects on the embryo. In natural ecosystems wood/lignin is broken down by ligninase enzymes produced by fungi, and this is of particular relevance to the germination and symbiotic development of certain groups of plants such as orchids. Here we analyze the hypothesis that ligninases derived from fungi can be used to break the seed coat and stimulate germination, with particular reference to wild orchids of semi-natural grasslands. In an initial experiment the enzyme laccase was administered to seeds of Himantoglossum adriaticum and Anacamptis morio under sterile conditions in vitro, using two methods: 1). incorporation of the enzyme directly into the agar substrate using cool filtration, or 2). "bathing" the seeds after sowing with the addition of a sterile solution of the enzyme. In both cases a concentration of 1 unit of active enzyme per seed batch/Petri dish was used. In a second experiment germination of A. morio was compared on substrates containing one of three different ligninase enzymes (laccase, lignin peroxidase and manganese peroxidase) added to the substrate at a concentration of 0.04 U/Petri (the highest achievable concentration within cost constraints – while laccase is inexpensive, lignin peroxidase and manganese peroxidase cost around two hundred times the price of gold). In the first experiment, after six months the final rate of germination for both species was double that of the controls, only when laccase was added to the substrate (in the case of A. morio from 25 to 50 %, while for H. adriaticum from 2 to 5 %; statistically significant at the P ≤ 0.05 level). In contrast, the “bathing” treatment significantly reduced germination compared to the control and also introduced contamination. In the experiment to compare enzymes, no treatment means showed significant differences from the control. In conclusion, lignin peroxidase and manganese peroxidase are too costly to allow useful amounts of enzyme to be applied. However, as laccase is inexpensive larger amounts can be applied and were found to be effective. The germination rates obtained may appear low, but for species that produce thousands of seeds per fruit such as orchids a doubling in germination can result in a significant increase in terms of the number of plants produced. The use of ligninases, particularly laccase, in the propagation of rare species thus appears to be highly promising because the intervention is targeted at the seed coat without the risk of potential complications during the development of the embryo
Utilizzo di alcuni semplici parametri fogliari per la definizione dell’ecologia di specie della flora italiana: indagini esplorative e primi risultati.
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I tipi funzionali come strumento per lo studio della dinamica di vegetazione: strategie delle piante e successione primaria in ambiente periglaciale.
No full textIl Centro per la Flora Autoctona della Regione Lombardia.
No full textThe “Centro per la Flora Autoctona” of Lombardy - Lombardy is characterized by a remarkable variety of plant communities and landscapes that often show a high species richness with the presence of several endemic and rare species. However the region is one of the first areas for density of population, development rate and productive activities in Italy and Europe as well: very peculiar ecosystems (limestone prairies, lowland heathlands, peat-bogs, etc.) often intermingle with towns, factories, quarries and so on. Beyond the traditional enterprises for the conservation of biological diversity based on the creation of protected areas, the regional administration has recently founded the “Centro per la Flora Autoctona” (Wild Plants Protection Centre), whose main aim is the acquisition of knowledge and techniques to warrant the availability of wild shrubs and herbs suited to 1) environmental restoration, and 2) rare and/or endangered species conservation project
Vernalization affects the germination performance of the wetland endangered species Eleocharis carniolica
No full textEleocharis carniolica W.D.J. Koch (Cyperaceae) is an endangered wetland spike rush mainly threatened by habitat loss and fragmentation. Understanding the germination ecology of this species is essential to perform successful conservation and restoration actions. In this study, we investigated the effect of vernalization (i.e. cold stratification), gibberellic acid (GA3) and chemical scarification on seed germination of E. carniolica from wild populations in northern Italy. The results showed that vernalization (i.e. 8-weeks at 4(degrees)C) significantly improved germination probability, speed, and uniformity compared to non-stratified seeds. Gibberellic acid treatment alone or in combination with vernalization did not show a significant improvement in germination. Chemical scarification using sodium hypochlorite increased germination probability, with 8 h of scarification showing the highest success rate. However, 24-h scarification had a negative impact on germination. Overall, vernalization was found to be the most effective method to enhance germination in E. carniolica. These findings provide valuable insights into the seed germination ecology of this endangered species, aiding in its exsitu conservation, propagation, and in-situ restoration efforts. Moreover, they have important implications on future germination dynamics of this endangered species, especially with predicted climate change scenarios
Coltivazione in vaso di specie erbacee perenni delle praterie prealpine: primi risultati.
No full textZnačilnosti kratke proze Roberta Bolaña
No full textDiplomsko delo skuša podati celosten pregled vseh štirih zbirk kratkih zgodb Roberta Bolaña in predstaviti glavne značilnosti njegove kratke proze. V večini zgodb zasledimo lik Artura Belana, Bolañevega alter ega, ki nastopa kot pripovedovalec, protagonist ali sekundarna oseba. Intertekstualnost je verjetno najpomembnejša lastnost celotne Bolañeve proze, avtor pa s konkretnimi primeri predstavi različne tipe intertekstualnosti, ki se pojavljajo v zgodbah. V zgodbi Sensini gre za poklon argentinskemu pisatelju Antoniu Di Benedettiju, v Beležki plesov (Carnet de baile) pa za kritiko Nerude in parodiranje biblične oblike besedila. V Podganjem policaju (El policía de las ratas) Bolaño prenese dogajalni prostor iz Kafkine zgodbe Pevka Jožefina ali mišji rod in variira temo umetnikove usode, v zgodbi Neznosni gaučo (El gaucho insufrible) pa gre za variacijo toposa civilizacija - barbarstvo, značilnega za južnoameriško književnost. Avtor v delu govori tudi o intermedialnosti med filmom in kratko prozo Roberta Bolaña, za konec pa analizira motive samote tekom umetnikovega ustvarjanja.Undergraduate thesis attempts to present an overview of Roberto Bolaño\u27s four short story collections and its most important characteristics. In the majority of the stories we come across Bolaño\u27s alter ego, a character named Arturo Belano, in the role of narrator, protagonist or secondary character. Intertextuality is probably the most importatnt characteristic of Bolaño\u27s prose and author\u27s goal is to present examples of different types of intertextuality in the stories. The story Sensini pays homage to Argentinian writer Antonio Di Benedetti, meanwhile Dance card mocks Neruda and parodies biblical text form. In the Police rat Bolaño borrows fictional world from Kafka\u27s Josephine the singer, or the mouse folk and writes a variation on the theme of artist\u27s fate. Author also writes about the variation of the famous South American literary topos (civilization - barbarity) which appears in the story The insufferable gaucho. Besides all that, this thesis talks about connection between film and Bolaño\u27s short stories and finishes with the analysis of the motive of loneliness in different periods of Bolaño\u27s work
Restoring with seed from semi-natural grasslands in Italian natural parks. The RISOPSta project, three years of experience in environmental recovery and the protection of biodiversity.
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