Search results for "Blight"
showing 10 items of 30 documents
From the roots to the stem: unveiling pear root colonization and infection pathways by Erwinia amylovora
2020
ABSTRACT Fire blight caused by Erwinia amylovora affects pome fruit worldwide, generating serious economic losses. Despite the abundant literature on E. amylovora infection mechanisms of aerial plant organs, root infection routes remain virtually unexplored. Assessing these infection pathways is necessary for a full understanding of the pathogen's ecology. Using the pathosystem Pyrus communis–E. amylovora and different experimental approaches including a green fluorescent protein transformant (GFP1) and epifluorescence microscopy (EFM) and laser confocal scanning microscopy (LCSM), we demonstrated the pathogen's ability to infect, colonize and invade pear roots and cause characteristic fire…
Genome-Wide Profiling and Phylogenetic Analysis of the SWEET Sugar Transporter Gene Family in Walnut and Their Lack of Responsiveness to Xanthomonas …
2020
Following photosynthesis, sucrose is translocated to sink organs, where it provides the primary source of carbon and energy to sustain plant growth and development. Sugar transporters from the SWEET (sugar will eventually be exported transporter) family are rate-limiting factors that mediate sucrose transport across concentration gradients, sustain yields, and participate in reproductive development, plant senescence, stress responses, as well as support plant&ndash
Different bacteria can enhance the micropropagation response of Cotoneaster lacteus (Rosaceae)
1998
C. MONIER, E. BOSSIS, C. CHABANET AND R. SAMSON. 1998. Cotoneaster species are widely used ornamental shrubs, and research is under way to select genotypes which are more resistant to fire blight by somaclonal variation. During the establishment of micropropagation, one genotype, Cotoneaster lacteus, showed the development of endogenous bacterial contaminants. Two strains were isolated from in vitro explants: Bacillus pumilus and Alcaligenes faecalis. These two strains, and some Pseudomonas fluorescens and Ps. putida, promoted in vitro multiplication and rooting of explants. In Pseudomonas strains, rooting enhancing capacity appeared to be related to indole-3-acetic acid (IAA) production, a…
Erwinia amylovora psychrotrophic adaptations: evidence of pathogenic potential and survival at temperate and low environmental temperatures
2017
The fire blight pathogenErwinia amylovoracan be considered a psychrotrophic bacterial species since it can grow at temperatures ranging from 4 °C to 37 °C, with an optimum of 28 °C. In many plant pathogens the expression of virulence determinants is restricted to a certain range of temperatures. In the case ofE. amylovora,temperatures above 18 °C are required for blossom blight epidemics under field conditions. Moreover, this bacterium is able to infect a variety of host tissues/organs apart from flowers, but it is still unknown how environmental temperatures, especially those below 18 °C, affect the pathogen ability to cause fire blight disease symptoms in such tissues/organs. There is als…
First Report of Diaporthe eres Associated with Cane Blight of Grapevine (Vitis vinifera) in Italy
2016
In March 2014, in a ‘Trebbiano’ vineyard in the province of Florence (Tuscany, Italy), 15% of the grapevines (Vitis vinifera L.) showed 1-year old canes with bleached areas, sometimes surrounded by dark margins, irregular dark blotches, and several dead buds. Canes were covered by black pycnidia, and occasionally cracks on the cortex were evident. Woody tissues under the bark were necrotic and canes broke easily. Fifteen symptomatic canes were collected from different vines and cane segments of 20 cm length were placed in a moist chamber and incubated at 25°C. After 72 h, a cream-white cirri mass of conidia was observed from pycnidia and it was plated onto potato dextrose agar (PDA) plates.…
Use of Botanicals to Suppress Different Stages of the Life Cycle of Fusarium graminearum
2019
Fusarium head blight (FHB) is one of the most important cereal diseases worldwide, causing yield losses and contamination of harvested products with mycotoxins. Fusarium graminearum is one of the most common FHB-causing species in wheat and barley cropping systems. We assessed the ability of different botanical extracts to suppress essential stages of the fungal life cycle using three strains of F. graminearum (FG0410, FG2113, and FG1145). The botanicals included aqueous extracts from white mustard (Sinapis alba) seed flour (Pure Yellow Mustard [PYM] and Tillecur [Ti]) as well as milled Chinese galls (CG). At 2% concentration (wt/vol), PYM and Ti completely inhibited growth of mycelium of …
Erwinia piriflorinigrans sp. nov., a novel pathogen that causes necrosis of pear blossoms
2010
Eight Erwinia strains, isolated from necrotic pear blossoms in València, Spain, were compared with reference strains of Erwinia amylovora and Erwinia pyrifoliae, both of which are pathogenic to species of pear tree, and to other species of the family Enterobacteriaceae using a polyphasic approach. Phenotypic analyses clustered the novel isolates into one phenon, distinct from other species of the genus Erwinia, showing that the novel isolates constituted a homogeneous phenotypic group. Rep-PCR profiles, PCR products obtained with different pairs of primers and plasmid contents determined by restriction analysis showed differences between the novel strains and reference strains of E. amylovo…
First Report of Southern Blight Caused by Sclerotium rolfsii on Hemp (Cannabis sativa) in Sicily and Southern Italy
2007
Hemp (Cannabis sativa L.), family Cannabaceae, is an annual herbaceous plant that is 1.5 to 4.0 m tall and native to the Caucasus Region, northern India, and Iran. It is cultivated in warm to temperate regions worldwide for its fiber, oil, and psychoactive substances. In Europe, commercial plantings have decreased from 52,872 ha in 1989 to 18,716 ha in 2005. Recently however, cultivation of hemp as a natural fiber species has been encouraged by European Union policy (2). During the summer of 2003, patches of dead plants were observed in test plots of 12 monoecious and dioecious hemp cultivars (Beniko, Epsylon 68, Felina 34, Ferimon, Fedora 17, Futura 75, Bialobrzeskie, Dioica 88, Fibranova…
Blight of English Ivy (Hedera helix) caused by Sclerotium rolfsii in Sicily
2007
English ivy, Hedera helix L. (Araliaceae), an evergreen climbing vine is widely cultivated as an ornamental and foliage plant. In the summer of 2005, a severe blight of ivy plants trained as topiaries and grown in an open field was observed in a nursery near Giarre (eastern Sicily). Foliage of infected plants appeared lighter green and progressively turned bronze and withered. Eventually, the entire plant collapsed. Foliar symptoms were associated with basal stem and root rot. White, cottony mycelium and numerous sclerotia developed externally on the lower stem and on the soil around the affected plants. The disease was randomly distributed, affecting approximately 5% of plants in a stock …
Survival of Erwinia amylovora in mature apple fruit calyces through the viable but nonculturable (VBNC) state
2009
Aims: Survival of Erwinia amylovora, causal agent of fire blight in pome fruits and other rosaceous plants, was monitored inside mature apples calyces under some storage conditions utilized in fruit. Methods and Results: Apple fruit calyces inoculated with two E. amylovora strains and their respective GFP-marked strains were maintained at 26° and 5°C, and the effect of copper treatment was assayed at 0·01 and 0·1 mmol l−1 CuSO4. In nontreated apples at 26°C, part of the population of E. amylovora survived in the ‘viable but nonculturable’ (VBNC) state, whereas at 5°C the majority of the population retained culturability. In copper-treated apples, the whole population adopted the VBNC stat…