scholarly journals Survival of Apple Rootstocks to Natural Infections of Fire Blight

2002 ◽  
Vol 12 (2) ◽  
pp. 239-241 ◽  
Author(s):  
D.C. Ferree ◽  
J.C. Schmid ◽  
B.L. Bishop
Keyword(s):  
Fire Blight ◽  
Erwinia Amylovora ◽  
Apple Rootstocks ◽  
Apple Trees ◽  
Wide Range ◽  
Dwarfing Rootstocks

Survival of replicated rootstock plantings of apple trees (Malus ×domestica) to fire blight (Erwinia amylovora) infection shows that a wide range of rootstock susceptibility exists. Trees on `Malling 26' (M.26), `Malling 9' (M.9), and `Mark' consistently had significant losses. Of the dwarfing rootstocks widely available commercially, `Budagovsky 9' (B.9) survived well with productive trees, but was not resistant to fire blight infection. The following experimental rootstocks had good survivability with many live productive trees in one or more trials: `Poland 2' (P.2), `Vineland 1' (V.1), `Malling 27 EMLA' (M.27 EMLA), `Budagovsky 491' (B.491), `Budagovsky 409' (B.409), `Vineland 7' (V.7), `Vineland 4' (V.4), and `Oregon Rootstock 1' (OAR1).

scholarly journals Fire Blight Symptomatic Shoots and the Presence of Erwinia amylovora in Asymptomatic Apple Budwood

Plant Disease ◽  
2017 ◽  
Vol 101 (1) ◽  
pp. 186-191 ◽  
Author(s):  
K. A. Tancos ◽  
E. Borejsza-Wysocka ◽  
S. Kuehne ◽  
D. Breth ◽  
Kerik D. Cox
Keyword(s):  
New York ◽  
Fire Blight ◽  
Erwinia Amylovora ◽  
Causal Agent ◽  
Economic Losses ◽  
Apple Trees ◽  
The Mean ◽  
Collection Practices ◽  
Time Of Collection ◽  
Young Apple

Erwinia amylovora, the causal agent of fire blight, causes considerable economic losses in young apple plantings in New York on a yearly basis. Nurseries make efforts to only use clean budwood for propagation, which is essential, but E. amylovora may be present in trees that appear to have no apparent fire blight symptoms at the time of collection. We hypothesized that the use of infected budwood, especially by commercial nursery operations, could be the cause, in part, of fire blight outbreaks that often occur in young apple plantings in New York. Our goal was to investigate the presence of E. amylovora in asymptomatic budwood from nursery source plantings as it relates to trees with fire blight symptoms. From 2012 to 2015, apple budwood was collected from two commercial budwood source plantings of ‘Gala’ and ‘Topaz’ at increasing distances from visually symptomatic trees. From these collections, internal contents of apple buds were analyzed for the presence of E. amylovora. E. amylovora was detected in asymptomatic budwood in trees more than 20 m from trees with fire blight symptoms. In some seasons, there were significant (P ≤ 0.05) differences in the incidence of E. amylovora in asymptomatic budwood collected from symptomatic trees and those up to 20 m from them. In 2014 and 2015, the mean E. amylovora CFU per gram recovered from budwood in both the Gala and Topaz plantings were significantly lower in budwood collected 20 m from symptomatic trees. Further investigation of individual bud dissections revealed that E. amylovora was within the tissue beneath the bud scales containing the meristem. Results from the study highlight the shortcomings of current budwood collection practices and the need to better understand the factors that lead to the presence of E. amylovora in bud tissues to ensure the production of pathogen-free apple trees.

RESISTANCE OF APPLE ROOTSTOCKS TO FIRE BLIGHT CAUSED BY ERWINIA AMYLOVORA

2004 ◽  
pp. 387-390 ◽  
Author(s):  
B.H. Barritt ◽  
B.S. Konishi ◽  
M.A. Dilley ◽  
L. Pusey
Keyword(s):  
Fire Blight ◽  
Erwinia Amylovora ◽  
Apple Rootstocks

scholarly journals Fire Blight Resistance of Budagovsky 9 Apple Rootstock

Plant Disease ◽  
2008 ◽  
Vol 92 (3) ◽  
pp. 385-391 ◽  
Author(s):  
Nicole L. Russo ◽  
Terence L. Robinson ◽  
Gennaro Fazio ◽  
Herb S. Aldwinckle
Keyword(s):  
Fire Blight ◽  
Erwinia Amylovora ◽  
Growth Habit ◽  
Blight Resistance ◽  
Apple Rootstock ◽  
Apple Rootstocks ◽  
Phenotypic Differences ◽  
Age Related ◽  
Multiple Trials ◽  
High Level

Erwinia amylovora, the causal agent of fire blight, can cause a fatal infection of apple rootstocks known as rootstock blight. Budagovsky 9 (B.9) apple rootstock is reported to be highly susceptible when inoculated with E. amylovora, although results from multiple trials showed that B.9 is resistant to rootstock blight infection in field plantings. Conflicting results could stem from genetic variation in the B.9 population, appearing as phenotypic differences in rootstock material. However, genetic testing, using 23 microsatellite loci, confirmed the clonal uniformity of B.9 in commerce. Variation in growth habit between B.9 rootstocks originating from two nurseries also has been discounted as a source of disease resistance. Instead, results indicate a possible novel resistance phenotype in B.9 rootstock. B.9 rootstock was susceptible to leaf inoculation by E. amylovora, statistically similar to the susceptible rootstock Malling 9 (M.9). Conversely, inoculation assays targeting woody 4- to 5-year-old tissue revealed a high level of resistance in B.9, whereas M.9 remained susceptible. Although the mechanism by which B.9 gains resistance to E. amylovora is unknown, it is reminiscent of age-related resistance, due to an observed gain of resistance in woody rootstock tissue over succulent shoot tissue. Durable fire blight resistance correlated with tissue development could be a valuable tool for rootstock breeders.

scholarly journals Draft Genome Sequences of Four Streptomycin-Sensitive Erwinia amylovora Strains Isolated from Commercial Apple Orchards in Ohio

2021 ◽  
Vol 10 (50) ◽  
Author(s):  
A. M. Jimenez Madrid ◽  
T. Klass ◽  
V. Roman-Reyna ◽  
J. Jacobs ◽  
M. L. Lewis Ivey
Keyword(s):  
Causative Agent ◽  
Fire Blight ◽  
Erwinia Amylovora ◽  
Draft Genome ◽  
Apple Orchards ◽  
Genome Sequences ◽  
Apple Trees ◽  
Content Type

Erwinia amylovora is the causative agent of fire blight, a devastating disease of apples and pears worldwide. Here, we report draft genome sequences of four streptomycin-sensitive strains of E. amylovora that were isolated from diseased apple trees in Ohio.

scholarly journals Testing the virulence of some Hungarian Erwinia amylovora strains on in vitro cultured apple rootstocks

2000 ◽  
Vol 6 (4) ◽  
Author(s):  
M. Hevesi ◽  
J. Papp ◽  
E. Jámbor-Benczúr ◽  
K. Kaszáné Csizmár ◽  
I. Pozsgai ◽  
...  
Keyword(s):  
Host Plants ◽  
Fire Blight ◽  
Erwinia Amylovora ◽  
Disease Development ◽  
Apple Rootstocks ◽  
Disease Rating ◽  
Different Strains

A useful method was improved to test and to evaluate the susceptibility of plants to fire blight and the virulence of E. amylovora strains. Six Hungarian strains from different host plants were tested on in vitro cultured apple rootstocks. Disease rating was used for the characterization of the process of disease development. The different strains had different capacity to cause disease, mainly in the first period of incubation. There were significant differences between the virulence of the strains.

scholarly journals Relation of Apple Flower Age to Infection of Hypanthium by Erwinia amylovora

Plant Disease ◽  
2008 ◽  
Vol 92 (1) ◽  
pp. 137-142 ◽  
Author(s):  
P. L. Pusey ◽  
T. J. Smith
Keyword(s):  
Fire Blight ◽  
Erwinia Amylovora ◽  
Disease Risk ◽  
Inoculum Potential ◽  
Apple Trees ◽  
Regression Curves ◽  
Different Temperatures ◽  
Flower Age ◽  
Simulated Rain ◽  
Crab Apple

Blossom age as related to hypanthial susceptibility to Erwinia amylovora is not well established, but is relevant to disease risk assessment. To test this, detached crab apple blossoms were maintained for various periods and at different temperatures before applying inoculum to hypanthia. Inoculum potential on hypanthia due to wetting was evaluated by subjecting detached stigma-inoculated blossoms (~106 CFU per flower) to varying amounts and durations of simulated rain (or dew) at 14°C. Blossoms of varying age on mature ‘Gala’ apple trees were inoculated on hypanthia with 102, 104, or 106 CFU per flower. In the laboratory, susceptibility decreased with flower age at rates that increased with temperature. Wetness periods up to 12 h resulted in populations on hypanthia of <103 CFU per flower; 24 h of wetness resulted in ~104 or ~105 CFU. A dose response was shown in the orchard, and regression curves indicated steepest decline of susceptibility during initial days after petal expansion. Disease models incorporating a blossom-age component may be effective because they indicate the potential for infection when temperatures favor rapid bacterial growth on stigmas within a window of high hypanthial susceptibility. Further investigation of these relationships could lead to advancements in determining fire blight risk.

RESISTANCE OF APPLE ROOTSTOCKS TO FIRE BLIGHT INFECTION CAUSED BY INTERNAL MOVEMENT OF ERWINIA AMYLOVORA FROM SCION INFECTIONS

2004 ◽  
pp. 229-234 ◽  
Author(s):  
H.S. Aldwinckle ◽  
N. LoGiudice ◽  
T.L. Robinson ◽  
H.T. Holleran ◽  
G. Fazio ◽  
...  
Keyword(s):  
Fire Blight ◽  
Erwinia Amylovora ◽  
Apple Rootstocks

scholarly journals Genome Sequence of the Biocontrol Agent Pantoea vagans Strain C9-1

2010 ◽  
Vol 192 (24) ◽  
pp. 6486-6487 ◽  
Author(s):  
Theo H. M. Smits ◽  
Fabio Rezzonico ◽  
Tim Kamber ◽  
Alexander Goesmann ◽  
Carol A. Ishimaru ◽  
...  
Keyword(s):  
Biological Control ◽  
Genome Sequence ◽  
Fire Blight ◽  
Erwinia Amylovora ◽  
Biocontrol Agent ◽  
Pantoea Agglomerans ◽  
Apple Trees ◽  
Gram Negative ◽  
Pantoea Vagans

ABSTRACT Pantoea vagans is a Gram-negative enterobacterial plant epiphyte of a broad range of plants. Here we report the 4.89-Mb genome sequence of P. vagans strain C9-1 (formerly Pantoea agglomerans), which is commercially registered for biological control of fire blight, a disease of pear and apple trees caused by Erwinia amylovora.

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