Search results for "Greening"

Leaf starch and nutrient responses to stem girdling and drought stress with respect to understanding HLB (greening) symptoms in citrus

2016

The most important problem in world citrus production is the bacterial disease Huanglongbing (HLB; greening) which is caused by a phloem-limited bacterium that is vectored by a phloem-feeding psyllid. The earliest visible symptoms of HLB in leaves are an asymmetrical chlorosis referred to as "blotchy mottle", thought to be from starch accumulation from a phloem dysfunction and a decline in root health. We tested the hypothesis that such visible symptoms are not unique to HLB by stemgirdling two year-old seedling trees of 'Cleopatra' mandarin and 'Swingle' citrumelo rootstocks in the greenhouse. Girdling induced a 4-fold greater starch concentration in leaves on well-watered trees while star…

Huanglongbing modifies quality components and flavonoid content of 'Valencia' oranges.

2014

BACKGROUND: In order to evaluate the effect of citrus greening disease, or Huanglongbing (HLB), on quality components and flavonoid contents of 'Valencia' oranges, fruit from non-infected trees (control), from infected trees but symptom-less (asymptomatic) and from infected trees and showing clear HLB symptoms (symptomatic) were harvested in March and in May, 2013. Fruit peel, pulp and juice were separated, the main quality components were determined, and hesperidin, nobiletin, tangeretin, narirutin and didymin were quantified using liquid chromatography. RESULTS: Peel colour, total soluble solids and citric acid were similar in control and asymptomatic fruits. Symptomatic fruits were small…

Development of the photosynthetic apparatus during light-dependent greening of a mutant of Chlorella fusca.

1977

The formation of chlorophyll, cytochrome f, P-700, ribulose bisphosphate carboxylase as well as photosynthesis and Hill reaction activities were tested during the light-dependent greening process of the Chlorella fusca mutant G 10. Neither chlorophyll nor protochlorophyllide was detected in the darkgrown cells. When transferred to light the mutant cells developed chlorophyll and established its photosynthetic capacity after a short lag phase. In the in vivo absorption spectra a spectral shift of the red absorption peak position from 674 to 680 nm was indicated during the first 3 h of greening. Cytochrome f was already present in the dark-grown cells, but during the greening phase a threefol…

Energy status and its control on embryogenesis of legumes: ATP distribution within Vicia faba embryos is developmentally regulated and correlated wit…

2003

To analyse the energy status of Vicia faba embryos in relation to differentiation processes, we measured ATP concentrations directly in cryosections using a quantitative bioluminescence-based imaging technique. This method provides a quantitative picture of the ATP distribution close to the in vivo situation. ATP concentrations were always highest within the axis. In pre-storage cotyledons, the level was low, but it increased strongly in the course of further development, starting from the abaxial region of cotyledons and moving towards the interior. Greening pattern, chlorophyll distribution and photosynthetic O2 production within embryos temporally and spatially corresponded to the ATP di…

Green infrastructures for the energetic and environmental sustainability of cities

2019

The inexorable extension of urbanization is consuming huge amounts of soil drastically reducing natural vegetation, replacing it with buildings and low albedo surfaces. The changes due to the different thermal properties of surface materials and the lack of evapotranspiration in urban areas lead to a phenomenon known as "urban heat island effect". By reintroducing the vegetation back into the urban landscape, a partnership between nature and cities should be strengthened to create a new sustainable urban environment. Since the outer surfaces of building offer a great amount of space for vegetation, planting on roofs and walls has become one of the most innovative way to provide several envi…

Greening island: Renewable energies mix to satisfy electrical needs of Pantelleria in Mediterranean sea

2016

In this article the authors analyze the renewable mix in order to satisfy the energy needs of a real island in the Mediterranean sea, Pantelleria, which represents an optimal starting point to increase the production of electrical energy from renewable sources in minor islands. In this text are exposed different alternative sources, such as solar, wind and wave energy. Moreover, it is exposed a project of an innovative conversion device proposed by Department of Energy of University of Palermo, compared to a different one proposed by Politecnico di Torino. The procedures applied in the present article, as well as the main equations used, are the result of previous applications made in diffe…

The sensitivity of buckwheat plants to pathogens under conditions of mixed viral and mycoplasmal infection

2016

It was investigated, that mixed infection of buckwheat distributed in various ecological regions of Ukraine, the pathogens that belong to different taxonomic groups have different and peculiar morphological and structural properties. First was shown that buckwheat is affected by buckwheat burn virus (BBV) together with Mycoplasma. Mixed infection leads to proliferation of sepals, clarification of the flowers petals, reduction and greening of petals, hypoplasia or hypodevelopment of stamens and pistils: all of this can lead to partial or complete sterility.

VEGETATED ROOFS: AN ENERGY, ENVIRONMENTAL AND ECONOMICAL OPPORTUNITY FOR GREENING THE BUILDINGS

2012

Huanglongbing modifies quality components and flavonoid content of ‘Valencia’ oranges

2015

BACKGROUND: In order to evaluate the effect of citrus greening disease, or Huanglongbing (HLB), on quality components and flavonoid contents of ‘Valencia’ oranges, fruit from non-infected trees (control), from infected trees but symptom-less (asymptomatic) and from infected trees and showing clear HLB symptoms (symptomatic) were harvested in March and in May, 2013. Fruit peel, pulp and juice were separated, the main quality components were determined, and hesperidin, nobiletin, tangeretin, narirutin and didymin were quantified using liquid chromatography. RESULTS: Peel colour, total soluble solids and citric acid were similar in control and asymptomatic fruits. Symptomatic fruits were small…

Carbohydrate and nutritional responses to stem girdling and drought stress with respect to understanding symptoms of Huanglongbing (HLB) in Citrus

2013

The most important worldwide problem in citrus production is the bacterial disease Huanglongbing (HLB; citrus greening) caused by phloem-limited bacterium Candidatus Liberibacter asiaticus. The earliest visible symptoms of HLB on leaves are vein yellowing and an asymmetrical chlorosis referred to as “blotchy mottle”, thought to be the result of starch accumulation. We tested the hypothesis that such visible symptoms are not unique to HLB by stem girdling 2-yr-old seedlings of two citrus rootstocks with and without drought stress in the greenhouse. After 31 d, girdling had little effect on shoot growth but girdling increased the relative growth rate of shoots in drought stressed trees. Starc…