scholarly journals Resistance of apple varieties and selections to Erwinia amylovora in the Czech Republic

2008 ◽  
Vol 44 (No. 3) ◽  
pp. 91-96 ◽  
Author(s):  
J. Korba ◽  
J. Šillerová ◽  
V. Kůdela
Keyword(s):  
Czech Republic ◽  
Fire Blight ◽  
Erwinia Amylovora ◽  
Relative Resistance ◽  
Lesion Development ◽  
The Czech Republic ◽  
Apple Cultivars ◽  
Moderately Resistant ◽  
Resistant Genotypes ◽  
Experimental Plots

Sixty-four apple cultivars and selections of potential interest to apple producers and plant breeders in the Czech Republic were tested for their relative resistance to the fire blight pathogen over six years. Level of fire blight resistance was evaluated according to the extent of lesion development on the shoots tips after artificial inoculation in experimental plots under insectproof nets. Cultivars Quinte (resistant) and Yellow transparent (high susceptible) were included in the tests. Of 64 apple cultivars and selections tested, none were high resistant, 3.1% were evaluated as resistant, 10.9% moderately resistant, 57.8% moderately susceptible, 21.9% susceptible and 6.3% high susceptible. Resistant apple genotypes, showing blight necrosis of shoots of 11–12%, were only cultivars Selena and Quinte. Moderately resistant genotypes (blight necrosis 13.1–25.0%) were Kordona, Golden Smoothee, Julia, HL 323, Melodie, HL 421 and S 634/3. High susceptible genotypes (blight necrosis more then 80.1%) were comprised cultivars Vesna, Topas, Yellow transparent and Vanda. The remaining genotypes were moderately susceptible (blight necrosis 26.1–60.0%) and susceptible (blight necrosis 60.1–80.0%). During six experimental years, quantitative variability was recorded in the blight score. Differences between cultivars in susceptibility to fire blight were often statistically significant.

scholarly journals Evaluation of susceptibility level of pear cultivars to fire blight (Erwinia amylovora) in the Czech Republic

2013 ◽  
Vol 40 (No. 2) ◽  
pp. 58-64 ◽  
Author(s):  
J. Korba ◽  
J. Šillerová ◽  
F. Paprštein ◽  
J. Sedlák ◽  
E. Prokinová ◽  
...  
Keyword(s):  
Czech Republic ◽  
Fire Blight ◽  
Erwinia Amylovora ◽  
The Czech Republic ◽  
Resistant Genotype ◽  
Proof Nets ◽  
Breeding Selection ◽  
Moderately Resistant ◽  
Resistant Genotypes ◽  
Alexander Lucas

Thirty-three pear cultivars and selections of potential interest to pear producers and plant breeders in the Czech Republic were tested for relative field susceptibility to the fire blight (Erwinia amylovora) over five years. Level of fire blight susceptibility was evaluated according to the extent of lesion development on the shoot tips after artificial inoculation in experimental plots under insect proof nets. Old cvs Alexander Lucas (as resistant standard), Conference (as moderately resistant standard) and Beurré Bosc (as susceptible standard) were included in the tests. The 33 pear cultivars and selections were tested, only one of them was highly resistant (3.0%), 3.0% were evaluated as resistant, 12.1% moderately resistant, 36.4% moderately susceptible, 18.2% susceptible and 27.3% highly susceptible. Breeding selection US 625-63-10 was the only highly resistant pear genotype (necrosis of shoots of 0–7.0%). Resistant genotype group (necrosis 7.1–13.0%) comprised US 625-63-4. Moderately resistant genotypes (necrosis 13.1–25.0%) included cvs Alexander Lucas, Alfa, Bohemica and HL 31-50-31. Highly susceptible genotypes (necrosis more than 80.1%) included cvs Vonka, Karina, Bona, Decora, Elektra, Milka, Regina, Alice and TE 4763. The remaining genotypes were moderately susceptible (necrosis 26.1–60.0%) and susceptible (necrosis 60.1–80.0%).    

scholarly journals Evaluation of reactions of commercial and autochthonous apple cultivars to common diseases in Serbia under natural infection

2017 ◽  
Vol 32 (3-4) ◽  
pp. 157-172 ◽  
Author(s):  
Jelica Balaz ◽  
Vladislav Ognjanov ◽  
Zoran Keserovic ◽  
Aleksandra Sucur ◽  
Jaap Janse ◽  
...  
Keyword(s):  
Erwinia Amylovora ◽  
Venturia Inaequalis ◽  
Natural Infection ◽  
Gold Rush ◽  
Podosphaera Leucotricha ◽  
The Czech Republic ◽  
Golden Delicious ◽  
The Usa ◽  
Apple Cultivars ◽  
Moderately Resistant

This study presents the results of a multiple-year evaluation (1991-1996; 2005-2007) of susceptibility of more than 100 apple cultivars to Venturia inaequalis, Podosphaera leucotricha and Erwinia amylovora under agroecological conditions existing in Serbia. Some of the most popular cultivars were found highly susceptible to V. inaequalis (Cripps Pink, Mutsu, Gloster 69, Wellspur); while Golden Delicious, Richared, Gala, Cacanska pozna, Cadel and Jonagold were susceptible; Idared, Granny Smith and Jonathan moderately susceptible; Lord Lamburne and London Pepping, as well as several autochthonous cultivars were moderately resistant; and a group of resistant cultivars included Prima, Priscilla, Williams Pride, Dayton, Enterprise, Gold Rush, Golden Orange, many of the Re-cultivars (Germany), as well as Baujade, Selena, Duk?t, Produkta, Topaz, some older cvs. (Worcester Pearmain, Merton Worcester, James Grieve, Akane, Astilish, Astrachan Red and Discovery), some Co-op selections (USA) and NS hybrids (Serbia). Regarding powdery mildew, Idared and Jonathan were highly susceptible; Gala, Akane, Jonagold, Priscilla, Mutsu, Cacanska pozna, Golden Delicious, Granny Smith, Cadel and GoldRush were susceptible; Wellspur, Astrachan Red, Richared, Jonadel, Dayton and several autochthonous cultivars were moderately susceptible; Lord Lamburne, Astlisch, Prima, Champagne Reinette, Discovery and many autochthonous cultivars were moderately resistant; while most Re-cvs. (Germany), several cultivars from the Czech Republic, some selections from the USA and UK and most NS hybrids (Serbia) were resistant. Also, some cultivars showed variable susceptibility depending on location (Williams Pride, Gloster 69, Baujade and Produkta). E. amylovora was observed only in 2007 and at relatively low intensity (up to 12% infection). The highest disease severity was observed on cv. Elstar, then Granny Smith, Idared and Jonagored; while the lowest was found on Red Chief and Hapke apple trees.

scholarly journals Testing of Czech cultivars and advanced selections of apples for fire blight (Erwinia amylovora) resistance

2011 ◽  
Vol 31 (No. 1) ◽  
pp. 7-11
Author(s):  
C. Fischer ◽  
K. Richter ◽  
J. Blažek
Keyword(s):  
Fire Blight ◽  
Erwinia Amylovora ◽  
Scab Resistance ◽  
Blight Resistance ◽  
The Czech Republic ◽  
Malus Floribunda ◽  
Apple Cultivars ◽  
High Level ◽  
Very High ◽  
Different Levels

Five apple cultivars from the Czech Republic and 26 selections from the same country (a majority of them were resistant to scab) were included in the present study. M. robusta strain (Nr. 5) was used as a control with the highest level of resistance to fire blight. Another 7 cultivars with different levels of resistance or susceptibility to the disease were also evaluated. Selena and Nabella were found to be resistant, whereas Angold, Resista and Topaz were susceptible. Two HL selections were previously identified as highly resistant, 3 selections as medium resistant and 7 others as moderately susceptible. The rest of the 14 selections ranged from very high susceptible to medium susceptible. A high level of resistance was confirmed in 3 cultivars from Dresden-Pillnitz: Reanda, Remo and Rewena. Comparison of the parentage of the tested cultivars or selections with their level of resistance to fire blight suggests that most of the resistance comes from Malus floribunda, which was used in the course of their breeding as a donor of scab resistance. In one case, the source of the fire blight resistance was Starking Delicious cv.  

Fire Blight Susceptibility in Pyrus Germplasm from Eastern Europe

HortScience ◽  
1990 ◽  
Vol 25 (5) ◽  
pp. 566-568 ◽  
Author(s):  
T. van der Zwet ◽  
R.L. Bell
Keyword(s):  
Eastern Europe ◽  
Fire Blight ◽  
Erwinia Amylovora ◽  
Breeding Program ◽  
Plant Germplasm ◽  
Plant Exploration ◽  
Moderately Resistant

During 1976-1980, three plant exploration trips were made throughout eastern Europe in search of native Pyrus germplasm. A total of 384 accessions (231 from Yugoslavia, 86 from Romania, 43 from Poland, and 12 each from Hungary and Czechoslovakia) were collected as budwood and propagated at the National Plant Germplasm Quarantine Center in Glenn Dale, Md. Following 8 years of exposure to the fire blight bacterium [Erwinia amylovora (Burr.) Winsl. et al.], 17.49” of the accessions remained uninfected, 11.2% rated resistant, 6.8% moderately resistant, and 64.6% blighted severely (26% to 100% of tree blighted). Some of the superior accessions have been released for use in the pear breeding program.

Evaluation of old Carpathian apple cultivars as genetic resources of resistance to fire blight (Erwinia amylovora)

Trees ◽  
2012 ◽  
Vol 27 (3) ◽  
pp. 597-605 ◽  
Author(s):  
Magdolna Tóth ◽  
Gitta Ficzek ◽  
Ildikó Király ◽  
Krisztina Honty ◽  
Mária Hevesi
Keyword(s):  
Genetic Resources ◽  
Fire Blight ◽  
Erwinia Amylovora ◽  
Apple Cultivars

scholarly journals Inflorescence blast and flower bud abnormalities of Spiraea × vanhouttei and their causes

2008 ◽  
Vol 43 (No. 4) ◽  
pp. 135-143 ◽  
Author(s):  
V. Kůdela
Keyword(s):  
Seed Production ◽  
Fire Blight ◽  
Erwinia Amylovora ◽  
Small Scale ◽  
Flower Bud ◽  
The Czech Republic ◽  
Hybrid Species ◽  
High Incidence ◽  
The Subject ◽  
Very High

In ornamental gardening, <I>Spiraea × vanhouttei</I> is a frequently planted spirea species in the Czech Republic. In 2003, there arose a suspicion of possible occurrence of fire blight caused by <I>Erwinia amylovora</I> on spirea shrubs in Prague and its environs. This suspicion was disproved for a certainty. The absence of the fire blight pathogen in symptomatic spirea plants stimulates a further effort to tackle the problem of a cause of conspicuous fire blight-like symptoms or inflorescence blast occurring on some spirea shrubs. The subject of this paper is: (i) to describe symptoms, incidence and severity of inflorescence blast, bud and flower abnormalities occurring in <I>Spiraea × vanhouttei</I> shrubs; (ii) to find out differences in the occurrence of blasted inflorescences between <I>Spiraea</I> species and cultivars with the intention of verifying the hypothesis that the blast inflorescence and sterility of some spirea species are associated with hybrid species. Symptoms of inflorescence blast are every growing season. No seed is produced by blasted inflorescences. Besides inflorescence blast, aborted floral buds appeared sporadically on a small scale. Spirea species were split into four categories according to the incidence of blasted inflorescences. Out of 52 species evaluated, 10% showed no or scarce incidence, 52% medium incidence, 27% high incidence and 11% very high incidence. The scarce incidence of blasted inflorescences was connected with the high seed production. And vice versa, very high incidence of blighted inflorescences was closely connected with no or low seed production or with high incidence of sterility. Fifteen out of the evaluated spirea species are the result of hybridization. These hybrids occur in each of the four categories of spirea species distinguished by the incidence of blasted inflorescence. However, it is remarkable that the highest incidence of hybrid spireas occurs in the category with the highest incidence of blasted inflorescence (83.33%). In the remaining three categories of spirea species, the proportion of hybrids ranged from 18 to 21%. It might indicate some connection of spirea hybrids with sterility.

scholarly journals Blackberry and raspberry are alternative resistance sources to fire blight

2017 ◽  
Vol 97 (1) ◽  
pp. 12-16 ◽  
Author(s):  
Ozer Calis ◽  
Cetin Cekic ◽  
Serhat Kara ◽  
Demet Celik Ertekin
Keyword(s):  
Bacterial Growth ◽  
Fire Blight ◽  
Erwinia Amylovora ◽  
Bacterial Pathogen ◽  
Post Inoculation ◽  
Resistance Sources ◽  
Pathogenicity Tests ◽  
Susceptibility And Resistance ◽  
Resistant Genotypes ◽  
Moderate Susceptibility

Erwinia amylovora causes fire blight mainly on pear, apple and quince trees. This bacterial pathogen also infects other Rosaceous plants, such as blackberry and raspberry. A race structure was established between an isolate of E. amylovora and berries using 40 wild blackberry and 7 wild raspberry genotypes. In pathogenicity tests, wild blackberry and raspberry genotypes had three phenotypic reactions: enhanced susceptibility, moderate susceptibility and resistance. We noted a higher bacterial growth of over 300 × 109 cfu mL-1 in plants with enhanced susceptibility, with resistant genotypes showing a bacterial growth of around 150 × 109 cfu mL-1. These results are also associated with symptoms observed at 29 days post-inoculation. This resistance is being evaluated to control fire blight.

scholarly journals Evaluation of a Cider Apple Germplasm Collection of Local Cultivars from Spain for Resistance to Fire Blight (Erwinia amylovora) Using a Combination of Inoculation Assays on Leaves and Shoots

HortScience ◽  
2009 ◽  
Vol 44 (5) ◽  
pp. 1223-1227 ◽  
Author(s):  
Alejandro Martínez-Bilbao ◽  
Amaya Ortiz-Barredo ◽  
Emilio Montesinos ◽  
Jesús Murillo
Keyword(s):  
Fire Blight ◽  
Erwinia Amylovora ◽  
Integrated Management ◽  
Germplasm Collection ◽  
Direct Selection ◽  
Breeding Programs ◽  
Detached Leaf ◽  
Apple Cultivars ◽  
Apple Production ◽  
Inoculation Assay

Fire blight, caused by the bacterium Erwinia amylovora, is among the three most important diseases of apple. A major effective method for its integrated management is the reduction of the susceptibility of the host. Cider apple production in Spain is based on local apple cultivars with minimum crop management and phytosanitary control. After the entry of fire blight in Spain, the selection and planting of cultivars with low susceptibility to this disease has thus become of paramount importance. In consequence, and as part of a wider characterization effort, we undertook the evaluation of an apple germplasm collection of local apple cultivars from Spain for susceptibility to fire blight. Because of the quarantine status of E. amylovora in Europe, we evaluated the use of a detached leaf inoculation assay in combination with a traditional shoot inoculation assay to reduce the amount of plant material to evaluate and to minimize pathogen manipulation. Comparison of the susceptibility values for 78 apple cultivars indicated a low but significant correlation (r = 0.56; α = 0.01) between the leaf and shoot inoculation methods. Although the detached leaf assay was not reliable for the direct selection of cultivars with low susceptibility, it was useful to optimize resources and limit the potential dispersal of the pathogen by allowing the exclusion of medium and highly susceptible cultivars from further evaluation. Shoot inoculation of 103 apple cultivars allowed the identification of 48 cultivars with high levels of resistance to fire blight, which could serve as starting material both for apple production and for breeding programs.

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