1,334 research outputs found
I sistemi riproduttivi delle piante
No full textLa riproduzione ha la finalità di perpetuare una
determinata specie nel tempo. Nel corso dell’evoluzione,
si sono sviluppati vari sistemi riproduttivi
attraverso i quali gli organismi viventi, come le
piante, si riproducono generando nuovi individui.
Nelle piante, a differenza di quello che succede nella
maggior parte del regno animale, coesistono la
riproduzione asessuale (agamica) e sessuale (gamica)
Elementi trasponibili
No full textLa classifi cazione dei trasposoni è complessa e,
utilizzando la modalità di classifi cazione riportata
nel database degli elementi trasponibili del mais
(http://maizetedb.org), possono essere suddivisi in
classi, sottoclassi, ordini, superfamiglie, famiglie e
sottofamiglie. Al più alto livello di classifi cazione,
i TE delle piante possono essere suddivisi in due
classi: TE di classe I (TE1) e TE di classe II (TE2).
La distinzione è principalmente basata sulla natura
dell’intermedio di trasposizione. Nei TE1 la trasposizione
avviene tramite un intermedio a RNA
prodotto per trascrizione del TE integrato nel genoma.Nei TE2 la
trasposizione avviene direttamente via DNA e la
loro trasposizione può avvenire con modalità tipo “taglia-e-incolla” e “copia-e-incolla”
PRELIMINARY STUDIES TO PROMOTE PHYTOREMEDIATION IN DEVELOPING COUNTRIES:THE CASE OF LAGO CHAMO.
No full textMorocco goes green : Le politiche ecologiche del Marocco - Parte 1
No full textDiscorso del re del Marocco a una conferenza di Ministri dell'Ambiente
Preliminary test of arsenic and mercury uptake by Poa annua
No full textArsenic (As) and mercury (Hg) are among the most dangerous heavy metals to humans andthe environment because of their toxicity towards all living organisms and their related accumulation capability. It is known that some plant species are able to detoxify water and soil fromsome pollutants. In this paperwe strive to investigate howa common plant species is able to accumulate these metals. In this research we considered Poa annua, a plant species easily growing in Italy and deeply involved in the food chain, to understand problems related to its use as fodder for wild and farm animals (i.e. cattle) and suitability to be used for phytoremediation purposes. Hydroponic experiments were set up; P. annua was seeded in different substrates: gravel and zeolite, alone and mixed at different percentage. For each metal three different levels of contamination were chosen, for As 0.25, 0.5 and 5mgL−1, for Hg 0.1, 0.2 and 2mg L−1. No substantial difference in metal absorption among plant samples watered with different As and Hg concentrations, was observed during the testing phase. Nevertheless, results show that concentrations of As and Hg accumulated in P. annua increase with the increasing contamination exposur
Altered levels of antioxidant enzymes associated with two mutations in tomato
No full textActivity of peroxidase, superoxide dismutase and catalase were examined in leaves, stems and roots of olivacea (oli) and monstrosa (mon) mutants of Lycopersicon esculentum Mill. The extent of the difference between the pattern of oxidative enzyme activities of the wild type (wt) and the mutants was determined. The high peroxidase activity during the developmental stages of the leaves and stems of oli and mon phenotypes is associated with high levels of 4 anodic peroxidases in leaves and of two isozymes in the stem. Leaves of oli exhibit higher activity of the cathodic peroxidase C2, while both mutations have a marked increase of peroxidase C1 in stems. A positive relation between high peroxidase activity and oxidative stress damage was found: in chilling experiments at 5°C, peroxidase level in mutants and wt leaves was negatively correlated with electrolyte leakage. Superoxide dismutase (SOD) activity rises in oli stems around flowering time due to the high activity of the chloroplast forms SOD‐1 and SOD‐2. Catalases (CAT) were detectable only in early stages of plant development; CAT‐2 was nearly absent in wild type tissues but well represented in mon and oli. The oli and mon mutations may affect critical steps of a regulatory pathway controlling various classes of oxidative enzymes in tomato. Copyright © 1993, Wiley Blackwell. All rights reserve
Molecular characterization of Citrus cultivars: Insight from recent studies
No full textCitrus fruits are an important nutritional source for human health and have immense economic value. Fruit development and ripening are key processes in the production of the phytonutrients, which are essential for a balanced diet and for disease prevention. The anthocyanins are responsible for red pigmentation in the flesh of sweet orange and one of the most important antioxidant compounds together with carotenoids (in particular lycopene) and ascorbic acid. These compounds contribute to protect against certain cancers, cardiovascular diseases, and other degenerative processes. The anthocyanin pathway is well described, and gene coding enzymes of the biosynthesis sequenced and analyzed at the molecular level. The generally identical structure and composition of genes taking part to anthocyanins pathway and their higher expression in blood oranges compared to common ones, suggested the investigation on regulatory network, in particular MYB transcription factors that play an important role in activation of the biosynthesis. In a recent study, the association of a long terminal repeat (LTR) to a Myb-like gene was found correlated to the red pigmentation in the flesh fruits of sweet orange cultivars. Citrus fruits are important also for their content of ascorbic acid. The gene transcription of key enzymes involved in the four known biosynthesis pathways of the vitamin C resulted up-regulated specifically in fruit, contributing to the high vitamin C accumulation in juice sacs. Moreover, new data related to the GalUR gene family in the citrus genome may suggest its involvement. The expected variability within Citrus species is low, due to the origin by spontaneous mutation and vegetative propagation, leading to a narrow genetic basis. Sweet orange, lemon, lime and grapefruit, are characterized by high heterozygosis, but nearly all cultivars are similar, as they originate from a common ancestor hybrid. Single nucleotide polymorphisms (SNPs) identification performed on various accessions of Citrus clementine and C. sinensis, confirmed the higher heterozygosity of sweet orange respect to clementine; and the presence of very few SNPs linked to agronomical characteristics. The development of next generation sequencing technologies will provide precise description of the genetic composition of citrus accessions and species. In particular, the availability of the citrus genome will permit to increase the opportunity identifying SNP markers to be used to develop citrus assay platforms for breeders. The further step will be to exploit both transcriptome and genome information to map the location of natural genetic variants that confer economically important traits mostly in the fruit
Il turismo nelle aree protette come leva per lo sviluppo sostenibile. Il caso dei parchi di montagna del Marocco.
No full textIl contributo espone i risultati condotti sul campo dall'autore in realzione alla sostenibilità del turismo in alcuni parchi montanio del Marocco, attraverso un'analisi di indicatori ambientali, sociali ed economic
Changes in superoxide dismutase and catalase activities in response to low temperature in tomato mutants
No full textCatalase and superoxide dismutase activities were examined in leaves of monstrosa and olivacea mutants of tomato after chilling stress
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