Search results for "Systematics"
showing 10 items of 6702 documents
Interaction of a host plant and its holoparasite: effects of previous selection by the parasite
2001
If parasites decrease the fitness of their hosts one could expect selection for host traits (e.g. resistance and tolerance) that decrease the negative effects of parasitic infection. To study selection caused by parasitism, we used a novel study system: we grew host plants (Urtica dioica) that originated from previously parasitized and unparasitized natural populations (four of each) with or without a holoparasitic plant (Cuscuta europaea). Infectivity of the parasite (i.e. qualitative resistance of the host) did not differ between the two host types. Parasites grown with hosts from parasitized populations had lower performance than parasites grown with hosts from unparasitized populations,…
Wuchsform und Organisation vonMonsonia nivea (Geraniaceae) unter besonderer Ber�cksichtigung der Blattstieldornen
1979
Monsonia nivea is a hemicryptophyte which shows spiny petioles after the loss of leaf blades. Anthocladial inflorescences and their supporting vegetative parts are spineless. Spines are formed only by vigorous rosettes. Similar spiny petioles can be found in all other genera of the tribeGeranieae.
SEM-Untersuchungen an myxospermen Diasporen
1980
The epidermal structure of mucilage producing seeds and fruits before and after contact with water is studied. Main emphasis is laid on the elucidation of structural peculiarities of the dessicated mucilaginous substances.
A prioritised inventory of crop wild relatives and wild harvested plants of Tunisia
2022
AbstractAn inventory of crop wild relatives (CWR) and wild harvested plants (WHP) occurring in Tunisia, based on the integration of the last available floristic checklists, is presented. The taxa were prioritised according to economic value of the related crop, potential for crop improvement, threat status, endemism, inclusion in the ITPGRFA (Annex I) and average annual contributions to dietary energy (kilocalories) per capita per day by applying a scoring system based on 4 priority levels. Of a total of 2912 taxa belonging to the Tunisian Flora, 2504 CWR and/or WHP (86% of the total), from 143 families and 686 genera, were identified, 2445 of which are CWR and 847 are WHP. In detail, 1654 …
Effects of arbuscular mycorrhizal fungi and maternal plant sex on seed germination and early plant establishment.
2015
Premise of the study: Arbuscular mycorrhizal fungi usually enhance overall plant performance, yet their effects on seed germi- nation and early plant establishment, crucial steps in plant cycles, are generally overlooked. In gynodioecious species, sexual dimorphism in these traits has been reported, with females producing seeds that germinate at a faster rate than seeds from hermaphrodites. • Methods: Using the gynodioecious plant Geranium sylvaticum, I investigated in a greenhouse experiment whether the presence of arbuscular mycorrhizal spores affects seed germination and early plant establishment, examining at the same time whether the sex of the mother producing the seeds also influence…
Co-Infections by Fusarium circinatum and Phytophthora spp. on Pinus radiata: Complex Phenotypic and Molecular Interactions
2021
13 Pág. Instituto de Ciencias Forestales (ICIFOR)
The Internal Dynamics of Fibrinogen and Its Implications for Coagulation and Adsorption
2015
Fibrinogen is a serum multi-chain protein which, when activated, aggregates to form fibrin, one of the main components of a blood clot. Fibrinolysis controls blood clot dissolution through the action of the enzyme plasmin, which cleaves fibrin at specific locations. Although the main biochemical factors involved in fibrin formation and lysis have been identified, a clear mechanistic picture of how these processes take place is not available yet. This picture would be instrumental, for example, for the design of improved thrombolytic or anti-haemorrhagic strategies, as well as, materials with improved biocompatibility. Here, we present extensive molecular dynamics simulations of fibrinogen w…
A cytological and ultrastructural study on the maturation and germination of oospores of Plasmopara viticola from overwintering vine leaves.
1999
Observations on cytological and ultrastructural changes in Plasmopara viticola oospores were carried out during the overwintering period. Three types of oospores were observed. Type I, characterized by a thin inner oospore wall (IOW), large lipid globules and two nuclei, was recovered only in samples collected in October. These oospores were considered to be immature. Maturation occurred during November and involved a noticeable increase in thickness of the IOW, fusion of nuclei, formation of an ooplast and break up of large lipid globules into smaller ones (type II oospores). A few oospores (type III) showed abnormal organization with very large lipid globules and less frequently discernib…
An evaluation of inoceramid single-prism sclerochronology
2020
Abstract Inoceramid prisms are among the most common microfossils that can be found in Late Cretaceous strata. Since these biomineral units were formed by sequential accretion in the outer shell layer of the bivalves, they potentially serve as archives of short-term (circa-annual) paleowater temperature fluctuations. In the present study, we tested to what extent intra-prismatic stable isotope variations of individual inoceramid prisms reflect sub-annual δ13C and the δ18O patterns. We obtained multiple carbonate samples from prisms recovered from the sediment and from a cross-sectioned inoceramid shell fragment and compared data from these samples to data from classical sclerochronological …
Osservazioni preliminari sulla tassonomia e la biogeografia di Microtus (Terricola) (Mammalia, Rodentia) fossile della Sicilia
2011
Biogeographia vol. )O(X - 2011 (Pubblicato il 23 dicembre 2011) La Biogeografia del/a Sicilia Osservazioni preliminari sulla tassonomia e la biogeografia di Micmtus (Terricola) (Mammalia, Rodentia) fossile della Sicilia ELISA LOCATELLP‘, FEDERICO MASINl**, DARIA PETRUSO**, BENEDETTO SALA*, GIOVANNI SURDI** * Dzpartimento di Biologzkz ed E2/oluzione, Univerritd degli Studi, 6.50 Ercole I d’Este 32, 44100 Fermm (Italy); e—mzzz'[: eZim.[ocate[[z'@unzfi. it; benedettoyzla @umfe. it *q‘ Dzpzzrtimento di Scienze dellzz Yerm e delMare, Universitzi degli Studi, z1z'czArc/Jimfi 22, 90123 Palermo (Italy) e—mai[: federico. masini @unz]m. it; dzzrizz._petru5o @um;mz. it; gz'0wmnz'.:um&#…