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901.
Abstract Preliminary ecological observations on Petagnia saniculifolia Guss., a rare sicilian endemism. — The Authors present the preliminary results of some observations on the anatomy and ecology of Petagnia saniculifolia Guss. and a synthetic phytosociological table in which some species of Molinio-Arrhenatheretea and Querco-Fagetea are present. The particular needs of this species and the precarious environmental conditions are pointed out. 相似文献
902.
Dott. Maria Cengia Sambo 《Plant biosystems》2013,147(3):471-483
903.
Abstract The effect of NaCl salinity and potassium supplement on growth, tissue ion concentration, photosynthesis, yield and fruit quality characteristics of tomato plants was studied. Tomato plants, hyb. Belladonna, were grown in 8.5 l pots, filled with 1:3 sand:perlite mixture and irrigated with a half-strength Hoagland solution through a closed hydroponic system. Six irrigation treatments were applied, including combinations of 3 salinity (0, 35 and 70 mM NaCl) and two potassium levels (K1: 200 ppm and K2: 400 ppm) in the nutrient solution. Salinity reduced photosynthesis resulting in reduced plant height and dry weight. Yield was reduced by 25% and 69% at 35 and 70 mM, respectively, as compared to control plants (0 mM NaCl). Both total soluble solids and titratable acidity of the fruit increased with increasing salinity and K levels. The application of high potassium level (K2) reduced the concentration of Na and increased that of K in the leaves and roots of the plants, as compared to K1 treatment. Toxicity symptoms were mostly observed in the leaves of 70K1 plants, while no visual symptoms of toxicity were observed in 70K2 treatment. Despite the positive effects of potassium supplement in reducing Na concentration and the absence of toxicity symptoms in the leaves, plant growth was not improved, while leaf photosynthesis was reduced. Furthermore, no positive effects in the percentage of marketable fruit, mean fruit weight and yield were observed in the plants receiving extra K. 相似文献
904.
Dott. Maria Arena 《Plant biosystems》2013,147(3-4):395-422
Summary The vegetative growth of the olive tree in Messina is described. The growth period begins at the end of March and prosecutes without interruption as late as November. The secondary wood tissue producted during summer time (from Yuly to August) is abnormal being of a parenchimatoide type. During winter there is a well defined rest period. The cambium produces secondary wood and bark with an alternate rythm, so that in spring the wood production prevails on the liber and in autumn the opposite condition is realized. Each phase of production of secondary conducting tissues (wood as well as bark) is followed by a phase of starch storing. In the stem several false wood rings are produced during one year, while in the young branches each wood ring corresponds to one year. The longitudinal growth and cork formation on the branches of the year are particularly pronounced during spring (March-May). Cambium cells swell in a characteristic way before they start dividing and collapse during the resting periods, thickening evidently their walls, so that in winter it is difficult to distinguish a cambial cell from a parenchimatic one. The behaviour of the vegetative growth of the olive tree in Messina is discussed on the base of the climatic characters of the region. 相似文献
905.
Dott. Maria Viesti 《Plant biosystems》2013,147(4):487-495
Summary The author has studied the flora of a few country lanes in the surroundings of Molfetta (Apulia). The various stations are described and the plants collected are listed. 相似文献
906.
907.
Abstract The content of polyamines and RNA in isolated embryos from dry resting seeds of durum wheat has been determined. This, with the aim to investigate the variations of the polyamines and RNA amounts during the ageing process and to correlate them with the loss of germination capacity of the seeds. The results showed that the total polyamines increase while the RNA content decreases during the ageing of the embryos. Since no great difference exists as to the polyamine content between the embryos from seeds capable and incapable to germinate, it appears to be lacking a close relationship between the polyamine content and the germination capacity of the examined seeds. The decrease of the RNA content and the corresponding increase of the polyamine-N/RNA-nucleotide ratio, seem to suggest that the loss of germination capacity of the wheat seed could be related to impaired regulation properties during the ageing process. 相似文献
908.
Abstract New researches on the culture « in vitro » of Aucuba japonica Thunb, – Caulinar fragments grown in vitro in nutrient media solidified with agar are compared with fragments grown on a filter paper support on unshaken liquid media. Tissue cultures of Aucuba are established putting down caulinar fragments just taken from the plant with isolated callus; subcultures are obtained more easily in July. We have observed that during the months of March or April, caulinar fragments, taken from the plant at various months of the year, of different ages and cultivated on various media, unexpectedly produce many roots. 相似文献
909.
Maria Pia Rigobello Roberto Stevanato Federico Momo Sabrina Fabris Guido Scutari Rita Boscolo 《Free radical research》2013,47(3):315-321
Propofol (2,6-diisopropylphenol), some substituted phenols (2,6-dimethylphenol and 2,6-ditertbutylphenol) and their 4-nitrosoderivatives have been compared for their scavenging ability towards 1,1-diphenyl-2-picrylhydrazyl and for their inhibitory action on lipid peroxidation. These products were also compared to the classical antioxidants butylated hydroxytoluene and butylated hydroxyanisole. When measuring the reactivity of the various phenolic derivatives with 1,1-diphenyl-2-picrylhydrazyl the following order of effectiveness was observed: butylated hydroxyanisole>propofol>2,6-dimethylphenol>2,6-di-tertbutylphenol?>?butylated hydroxytoluene. In cumene hydroperoxide-dependent microsomal lipid peroxidation, propofol acts as the most effective antioxidant, while butylated hydroxyanisole, 2,6-di-tertbutylphenol and butylated hydroxytoluene exhibit a rather similar effect, although lower than propofol. In the iron/ascorbate-dependent lipid peroxidation propofol, at concentrations higher than 10?μM, exhibits antioxidant properties comparable to those of butylated hydroxytoluene and butylated hydroxyanisole. 2,6-Dimethylphenol is scarcely effective in both lipoperoxidative systems. The antioxidant properties of the various molecules depend on their hydrophobic characteristics and on the steric and electronic effects of their substituents. However, the introduction of the nitroso group in the 4-position almost completely removes the antioxidant properties of the examined compounds. The nitrosation of the aromatic ring of antioxidant molecules and the consequent loss of antioxidant capacity can be considered a condition potentially occurring in vivo since nitric oxide and its derivatives are continuously formed in biological systems. 相似文献
910.
Maria Eugenia Carlotti Elena Ugazio Simona Sapino Ivana Fenoglio Giovanna Greco Bice Fubini 《Free radical research》2013,47(3):312-322
TiO2 nanoparticles hazard is associated to their photocatalytic activity causing release of DNA damaging ROS (Reactive Oxygen Species), lipid peroxidation and skin damage. Various coatings have been proposed to minimize photocatalysis, while keeping the potential to block UV radiations. Uncoated and variously coated commercial nano-titania have been classified on the basis of UVB-induced lipoperoxidation of linoleic acid. A selection of the most and the least protective specimens was then examined by ESR (Electron Spin Resonance) to evidence the presence of surface paramagnetic centres and the release of ROS in aqueous suspensions (spin trapping). Paramagnetic centres and ROS were correlated with the extent of lipid peroxidation. When tested on porcine skin (mimicking the human one), titania acted as on linoleic acid. The combined use of lipid peroxidation of simple fatty acids with ESR analysis is here proposed as a possible screening tool for the evaluation of the potential toxicity of nano-titania in sunscreen preparations. 相似文献