Search results for "FISIOLOGIA VEGETAL"
showing 10 items of 57 documents
Elimination of Citrus variegation virus (CVV) by seed cryotherapy
2014
Citrus variegation ilarvirus (CVV) is one of the oldest viruses reported in Citrus, which produces crinkling, puckering and variegation of leaves in field trees and, occasionally, variegated and deformed fruits. This virus is primarily transmitted by grafting. However, no consistent data are available concerning CVV seed transmission, which is apparently low. The elimination of CVV in citrus genotypes is carried out by shoot-tip-grafting. In the case of seed sources, virus elimination directly in the seeds becomes essential. In cryotherapy, plant pathogens such as viruses, phytoplasmas and bacteria are eradicated by exposing explants to liquid nitrogen. It allows treatment of a high number …
An Investigation of the Seasonal Pattern of Mannitol Content in Deciduous and Evergreen Species of the Oleaceae Growing in Northern Sicily
2002
In several species of the Oleaceae, mannitol, already present at considerable levels, accumulates in response to stress. This family comprises both deciduous and evergreen species, and we investigated the role of mannitol in deciduous malacophyll and evergreen sclerophyll species growing under the same conditions in the field. The relationship between mannitol content and changes in rainfall or temperature was also studied. The mannitol content of leaves of Fraxinus ornus L., F. angustifolia Vahl., Olea europaea L. and Phillyrea media L. was determined by gas chromatography. Leaf samples were collected once a month for 1 year. In the two ash species, the seasonal pattern of mannitol content…
IN-VITRO REGENERATION OF CALENDULA MARITIMA GUSS. (ASTERACEAE), A THREATENED PLANT ENDEMIC TO WESTERN SICILY
2016
Calendula maritima is a critically endangered endemic plant of Western Sicily. Besides habitat destruction, the hybridization with the contiguous congener species C. fulgida is a major threat to its conservation. For this reason, seed-based propagation and seed storage are not appropriate for conservation purposes. In the present paper we describe a rapid and prolific in vitro plant regeneration method by direct organogenesis from leaves of C. maritima. Leaf explants were cultured on solid Murashige and Skoog (MS) medium in the presence of several plant growth regulator combinations. The best shoot multiplication rate (2.5 shoots/explant) was obtained on the medium containing 4.4 µM 6-benzy…
Nuove frontiere della fotosintesi clorofilliana: la foglia artificiale
2013
Per molti anni la scienza ha tentato di riprodurre il processo fotosintetico delle piante, che permette di utilizzare la luce del sole e l'anidride carbonica dell'atmosfera per produrre gli zuccheri necessari al loro metabolismo. Nella primavera del 2010 sui quotidiani compare la notizia rivoluzionaria della creazione di una foglia artificiale, capace di trasformare la luce in una fonte di energia utilizzabile dall'uomo. Su quali principi si basa questa scoperta? Quanto ha di analogo con i processi che avvengono nelle foglie? E quanto siamo vicini all'applicazione su vasta scala di questa innovazione tecnologica?
Seasonal pattern of mannitol and malate accumulation in leaves of two manna ash species (Fraxinus ornus L. and F. angustifolia Vahl) growing in Sicily
2002
The content of mannitol and malate was assayed enzimatically during spring, summer and autumn, in leaves of two species of ash traditionally cultivated in Sicily for the extraction of manna. The results suggest that in these species, under the local field conditions, mannitol has a more relevant role than malate in the response to summer drought.
Effects of foliar application of glycine betaine and chitosan on Puccinellia distans (Jacq.) Pari, subjected to salt stress.
2019
Introduction:Using brackish water for irrigation may expose turfgrasses to salinity stress.Employing the best treatments to maintain high-quality turfs under saline conditions is animportant requirement for turfgrass management.Methods:We tested the response of ahalophyte grass,Puccinellia distans, to irrigation with saline solutions and to foliarapplication of two osmoprotectants, such as glycine betaine (GB) or chitosan (CH). Plantswere grown in pots under controlled conditions and irrigated with 200 mM or 600 mM ofNaCl solutions. The response to salinity treatments and osmoprotectant application wasevaluated after 90 days by measuring leaffiring, leaf density, shoot length and biomass, r…
Effectiveness of glycinebetaine foliar application in relieving salt stress symptoms in two turf-grasses
2014
Salinity is one of the problems that has to be dealt with in turf-grass management, due both to restrictions in freshwater use for landscape irrigation and exposition to salt stress in coastal areas. This has led to the need to select salinity tolerant genotypes and test management practices, such as the application of osmoprotectants, in order to maintain turf quality at acceptable costs. We compared the effects of irrigation with 600 mM NaCl and glycinebetaine (GB) application for 8 weeks on pot-grown weeping alkaligrass (Puccinellia distans (L.) Parl.) and tall fescue (Festuca arundinacea Schreb.). We selected two easily assessable parameters, total clippings fresh weight and chlorophyll…
Does short-term potassium fertilization improve recovery from drought stress in laurel?
2014
Xylem hydraulic conductance varies in response to changes in sap solute content, and in particular of potassium (K(+)) ion concentration. This phenomenon, known as the 'ionic effect', is enhanced in embolized stems, where it can compensate for cavitation-induced loss of hydraulic conductance. Previous studies have shown that in well-watered laurel plants (Laurus nobilis L.), potassium concentration of the xylem sap and plant hydraulic conductance increased 24 h after fertilization with KCl. The aim of this work was to test whether water-stressed laurel plants, grown under low potassium availability, could recover earlier from stress when irrigated with a KCl solution instead of potassium-fr…
Seasonal variation in total phenolic content of Dictyopteris polypodioides (Dictyotaceae) and Cystoseira amentacea (Sargassaceae) from the Sicilian c…
2013
Phlorotannins are polyphenolic secondary metabolites found in almost all brown algae that function as defense against grazers, pathogens and epiphytes but are also involved in photoprotection mechanisms. These compounds, produced in the Golgi apparatus, are accumulated in cytoplasm, within vesicules called physodes, or bound to the cell wall. The concentration of phlorotannins dif-fers within and between species, shows geographical variations but may be also affected by abiotic or biotic factors. Aims of this study were to evaluate: (i) the temporal variation of total phenolic content in two brown algae, Dictyopteris polypodioides and Cystoseira amentacea, living respec-tively in the upper …
Monitoring of alien aquatic plants in the inland waters of Sicily (Italy)
2020
Updated and reliable data on the presence and distribution of alien aquatic plant species in Sicily are lacking, and there is a need to fill this gap for a proper and efficient management of freshwater ecosystems and biodiversity. This paper reviews the available knowledge about alien aquatic vascular plants in the inland waters of Sicily (Italy). The aim is to provide an updated checklist, as a first step in the study of the impact of those plants on the native species and ecosystems of this Mediterranean island. The paper focuses on the strictly aquatic species (hydrophytes), excluding emergent macrophytes. Four species were listed, all of them free-floating and with American origin. Most…