117,640 research outputs found
Tolerance degree of some maize (Zea mays) hybrids to rimsulfuron1
No full textThe degree of tolerance to the sulfonylurea herbicide rimsulfuron (R) was investigated
in five different commercial maize hybrids: Sirena (Si), Sara (Sa), Eleonora (El),
Gitana (Gi) and Lucia (Lu). The susceptibility of the hybrids to R treatment was
investigated by checking their protein content and evaluating R persistence in the
maize hybrids as well as the activity and kinetic parameters of the target enzyme
they contain, acetolactate syntase (ALS). 72 hours after treatment, decreases in
the protein content were considerable in Gi and Lu, moderate in El, and not significant
in Si and Sa. At the same time El, Lu and Gi exhibited significant R residues, while
the herbicide was completely metabolized in Si and Sa. The values of extractable ALS
activity in the untreated hybrids ("native" ALS) - with and without R addition in the
reaction mixture - and in the R-treated hybrids, together with the ALS V and K
parameters of the untreated and R-treated hybrids, evidenced varying degrees of
tolerance to R among the hybrids. Despite the susceptibility of "native" ALS in all
of the hybrids to R, Si and Sa appeared to overcome the action of R through a rapid
detoxifying capability, and El through an ability to produce more ALS enzymes in
response to R treatment. Gi and Lu exhibited a lower tolerance to R since they were
unable to activate any of the above mechanisms.Degré de tolérance au rimsulfuron de certains hybrides de maïs. Le degré de tolérance à
l'herbicide sulfonyl-urée rimsulfuron (R) a été étudié chez cinq hybrides différents
de maïs Sirena (Si), Sara (Sa), Eleonora (El), Gitana (Gi) et Lucia (Lu). Pour étudier
la sensibilité des hybrides au traitement avec R, on a contrôlé leur teneur en protéines
et évalué les paramètres cinétiques et d'activité de l'enzyme-cible qu'ils contiennent,
l'acétolactate synthétase (ALS). Soixante douze heures après le traitement, on a relevé
une diminution considérable de la teneur en protéines chez Gi et Lu, modérée chez El et
non significative chez Si et Sa. Dans le même temps, El, Lu et Gi ont montré des résidus
significatifs de R, tandis que l'herbicide avait été complètement métabolisé chez Si
et Sa. Les valeurs de l'activité d'ALS que l'on a pu relever dans les hybrides non
traités (ALS "à l'état natif " ) - avec ou sans adjonction de R dans le mélange de
réaction - et dans les hybrides traités avec R, ainsi que les valeurs des paramètres
V et K d'ALS des hybrides non traités et traités avec R ont permis de relever
des degrés variables de tolérance à R parmi les hybrides. Malgré la sensibilité
envers R de l'ALS "à l'état natif " de tous les hybrides, on a pu voir que Si et
Sa surmontaient l'action de R par le biais d'une capacité de métabolisation rapide,
et El grâce à sa capacité de produire davantage d'enzymes ALS en réponse au traitement
avec R. Par contre, Gi et Lu, incapables d'activer les mécanismes ci-dessus, ont donc
fait apparaître une tolérance moindre à R
Destino ambientale dei fitofarmaci: modelli matematici per la previsione del movimento nel terreno (PLMs)
No full textCollana Tecnico-scientifica quaderno n°
Integration of palaeontological patterns in the sequence stratigraphy paradigm: a case study from Holocene deposits of the Po Plain (Italy)
No full textLong-term monitoring and complementary laboratory measurements. Oceanographic campaign in the Adriatic Sea.
No full textIMTEC Second-year Meeting, Venice 8/02/03
Glutathione S-transferases in Festuca arundinacea : Identification, characterization and inducibility by safener benoxacor
No full textOver recent years it has emerged how certain no crop-species can be employed in phytoremediating contaminated soils or preventing
herbicide pollution; in this contest Festuca arundinacea was investigated. Shoots of Festuca were submitted to fast protein liquid chromatography
in order to identify their glutathione S-transferases (GST; EC 2.5.1.18), by a combination of anionic, affinity and RP-HPLC
chromatography. The chromatographic procedure revealed satisfactory yield and four GSTs were identified: they were named FaGST I,
FaGST II, FaGST III and FaGST IV. Among these, significant differences were observed in the chromatographic behaviours, structure,
activity toward a ‘‘model’’ substrate, 1-chloro-2,4-dinitrobenzene, and responsiveness to the herbicide safener benoxacor. FaGST I
showed the highest activity toward the above substrate, and this activity was up-regulated by the herbicide safener. Therefore, FaGST
I was purified till homogeneity and was determined to be an heterodimer consisting of two subunits of 28.0 and 27.2 kDa. Each subunit
of FaGST I was further characterized by means of LC–ESI–MS/MS and immunoblotting analysis, which revealed that both the subunits
belong to the tau subclass
Herbicide losses in runoff events from a field with a low slope: Role of a vegetative filter strip
No full textHerbicide runoff and the effects of a narrow vegetative filter strip (VFS) were studied on an arable field in the low-lying plains of the Veneto Region (north-east Italy). Cultivated plots were compared with and without a 6 m wide VFS composed of trees, shrubs and grass. Natural and simulated runoff were monitored during 2000 and 2001. Herbicides applied on the field were: metolachlor (2184-2254 g ha(-1)), terbuthylazine (1000-1127 g ha(-1)) and isoproturon (1000 g ha(-1)). The VFS reduced both runoff depth (10.2-91.2%) and herbicide losses (85.7-97.9%) in the monitored rainfall events. Total herbicide loss with runoff was low (0.69-3.98 g ha(-1) without VFS, less than 0.27 g ha(-1) with VFS), but concentrations were sometimes very high, especially of terbuthylazine and isoproturon during the first events after treatment. In these events there was a high probability of exceeding the ecotoxicological endpoint for algae, but the VFS helped to reduce the potential risk. Two VFS effectiveness mechanisms were identified: (i) dilution, and (ii) a "sponge-like" effect, which temporarily trapped chemicals inside the VFS before releasing them
La pesata dei filtri di raccolta di aerosol in Antartide.
No full textVenezia 18-19/4/2001. Atti del Convegno (Riass. Estesi), pp. 14-25
Relationship between rimsulfuron degradation and microbial biomass content in a clay-loam soil
No full text- …
