Search results for "DISEASE RESISTANCE"

Stilbene Content of MatureVitis viniferaBerries in Response to UV-C Elicitation

2001

A method using HPLC analysis has been used to compare the level of resveratrol and its derivatives, piceid, pterostilbene and epsilon-viniferin, in grapevine berries of three Vitis vinifera varieties. The concentration of these compounds has been evaluated in healthy and Botrytis cinerea infected grape clusters, both in natural vineyard conditions and in response to UV elicitation.

Development of methods using phytoalexin (resveratrol) assessment as a selection criterion to screen grapevine in vitro cultures for resistance to gr…

1995

The purpose of this research was, firstly to determine the ability of grapevine in vitro cultures to synthesize resveratrol, a stilbene-type phytoalexin that is considered to be a good marker for resistance of grapevines to Botrytis cinerea, the causal organism for grey mould. Secondly, this study sought to establish the relationship between phytoalexin production potential and resistance to Botrytis cinerea in grapevines. In this aim, resveratrol production was assessed in 13 Vitis species or cultivars. A good correlation appeared between resveratrol production by grapevine in vitro cultures and grey mould resistance except for two Vitis spp. for which no correlation was observed, thus sug…

STUDY ON CONVERSION OF ENCAPSULATED VITRO-DERIVED PROPAGULES OF 'C35' CITRANGE [C. SINENSIS (L.) OSB. × P. TRIFOLIATE (L.) RAF.]

2015

Fight against Citrus tristeza virus (CTV) implies the use of CTV-resistant rootstocks, such as citranges [C. Sinensis (L.) Osb. × P. Trifoliata (L.) Raf.]. The 'C35' represents a promising tolerant to CTV genotype. The employment of innovative in vitro techniques, such as encapsulation, could open new perspectives for this genotype propagation, particularly in the nursery activity. Preliminary experiments on calcium-alginate encapsulation of microcuttings (unipolar propagules) have already been performed to evaluate the use of tissue culture for the propagation and the preservation of different citrange rootstocks: Carrizo and Troyer. In the present study, the influence of different types a…

Presence of endophytic bacteria in Vitis vinifera leaves as detected by Fluorescence in situ hybridization

2010

Fluorescence in situ hybridization (FISH) in combination with confocal laser scanning microscopy (CLSM) was applied to detect and localize bacterial colonies in leaf tissues of Vitis vinifera. Leaves were cleared to minimize the autofluorescence of plant fragments. The use of fluorescently labeled bacterial probe EUB338 on discolored grapevine leaf disks allowed the estimation of the spatial distribution of different bacterial colonies. In particular, bacterial colonies were found in veins, cells, hairs, intercellular spaces, and in cut edges of leaf disks of both non-Acremonium byssoides-colonized and A. byssoides-colonized leaves of five different cultivars. Furthermore, CLSM confirmed th…

Role of dioxygenase α-DOX2 and SA in basal response and in hexanoic acid-induced resistance of tomato (Solanum lycopersicum) plants against Botrytis …

2015

Resistance of tomato (Solanum Lycopersicum) to the fungal pathogen Botrytis cinerea requires complex interplay between hormonal signalling. In this study, we explored the involvement of new oxylipins in the tomato basal and induced response to this necrotroph through the functional analysis of the tomato α-dioxygenase2 (α-DOX2)-deficient mutant divaricata. We also investigated the role of SA in the defence response against this necrotrophic fungus using SA-deficient tomato nahG plants. The plants lacking dioxigenase α-DOX2, which catalyses oxylipins production from fatty acids, were more susceptible to Botrytis, and hexanoic acid-induced resistance (Hx-IR) was impaired; hence α-DOX2 is requ…

Viruses of Cetaceans

2011

Ultraviolet B radiation induced alterations in immune function of fish : in relation to habitat preference and disease resistance

2009

Runsas altistuminen auringolle on tunnetusti haitallista ihmisten ja eläinten hyvinvoinnille. Eveliina Markkula tutki väitöskirjatyössään, miten ultravioletti B (UVB) -säteilylle altistuminen vaikuttaa kalojen vastustuskykyyn ja tautialttiuteen.- Ilmakehän otsonikerroksen oheneminen viime vuosikymmenten aikana on johtanut UVB-säteilyn lisääntymiseen maan pinnalla. UVB-säteily tunkeutuu myös kirkkaisiin järvi- ja merivesiin ja voi näin aiheuttaa haittaa kaloille, Markkula kertoo.UVB-säteilyn on jo aiemmin todettu lisäävän kalojen varhaisten elinvaiheiden epämuodostumia ja kuolleisuutta. Kertaluonteinenkin altistuminen lampuilla tuotetulle UVB-säteilylle aiheuttaa muutoksia kalan immuunijärje…