Phenotyping early blight resistance in potato cultivars and breeding clones

Odilbekov, Firuz; Carlson-Nilsson, Ulrika; Liljeroth, Erland

doi:10.1007/s10681-013-1054-4

Cited by 31 publications

(38 citation statements)

References 34 publications

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“…The final concentration of acetone in all media was 0.1 % ( v/v ). Spores of A. solani were produced [27] and the spore suspension was adjusted to 2 × 10 4 conidia mL −1 . Fifty microliters of conidial suspension of each isolate was spread across the agar plates, containing different concentrations of azoxystrobin/pyraclostrobin (two replicate plates) and on control plates (two replicate plates).…”

Section: Methodsmentioning

confidence: 99%

Genetic diversity and occurrence of the F129L substitutions among isolates of Alternaria solani in south-eastern Sweden

et al. 2016

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BackgroundEarly blight, caused by the fungus Alternaria solani, occurs on potato mainly in the south-eastern part of Sweden, but also in other parts of the country. The aim of this study was to investigate the genetic diversity of A. solani populations from different potato growing regions in south-eastern Sweden using AFLP marker analysis. In addition, the cultured isolates were examined for substitutions in the gene encoding cytochrome b, associated with loss of sensitivity against QoI fungicides.ResultsNei's gene diversity index for the Swedish populations of A. solani revealed a gene diversity of up to 0.20. Also genetic differentiation was observed among populations of A. solani from different locations in south-eastern Sweden. The mitochondrial genotype of the isolates of A. solani was determined and both known genotypes, GI (genotype 1) and GII (genotype 2), were found among the isolates. The occurrence of the F129L substitution associated with a loss of sensitivity to strobilurins was confirmed among the GII isolates. In vitro conidial germination tests verified that isolates containing the F129L substitution had reduced sensitivity to azoxystrobin and, at a lower extent, to pyraclostrobin.ConclusionsGenetic diversity was relatively high among isolates of A. solani in south-eastern part of Sweden. F129L substitutions, leading to reduced sensitivity to strobilurins, have been established in field populations, which may have implications for the future efficacy of QoI fungicides.

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Section: Methodsmentioning

confidence: 99%

Genetic diversity and occurrence of the F129L substitutions among isolates of Alternaria solani in south-eastern Sweden

et al. 2016

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“…Unfortunately, no potato cultivar has been reported to be completely resistant to early blight. However, cultivar resistance to early blight has been reported to be horizontal or partial in nature; thus the intensity of the disease varies on different cultivars (Holley et al, 1983;Christ, 1990;Boiteux & Reifschneider, 1993;Duarte et al, 2014;Odilbekov et al, 2014), compared to vertical or complete resistance where infection is totally stopped. Besides, resistance to early blight has been shown to be related to foliage maturity of the cultivar (Christ, 1990;Duarte et al, 2014); early maturing cultivars are the most susceptible, whereas late maturing cultivars show less susceptibility (Johanson & Thurston, 1990).…”

Section: Introductionmentioning

confidence: 99%

“…epidemiological parameters or 'curve elements', that describe the disease development and allow susceptibility to be compared and that are key to comparing disease epidemics (Campbell et al, 1980). Usually, curve elements such as the rate of the disease progress, area under the disease progress curve (AUDPC), and time to reach 50% severity can be used singly (Holley et al, 1983;Odilbekov et al, 2014) or simultaneously in a multivariate analysis to compare disease epidemics on different cultivars to identify partial resistance (Anderson et al, 1990;Duarte et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

Resistance status of cultivated potatoes to early blight (Alternaria solani) in Denmark

2017

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Field experiments were conducted in 2015 and 2016 to classify the resistance level to early blight of the main potato cultivars in Denmark. A total of 38 cultivars were used. The experiment was designed as a randomized complete block design (RCBD) with four replicates. The potatoes were inoculated by spreading barley (Hordeum vulgare) kernels infested with Alternaria solani and A. alternata. Disease assessment was done at weekly intervals starting from the onset of the first symptoms. The disease progress curves (DPC) of early blight on the cultivars were compared to that of Bintje. A multivariate analysis was performed with the apparent infection rate, the relative area under the disease progress curve, the time to reach 50% severity, the daily defoliation, the disease severity in the middle of the epidemic and the duration of the epidemic to classify the resistance level of the cultivars. The analysis of the DPC of the cultivars showed that none of the cultivars was completely resistant to early blight. However, the epidemic development differed between the different cultivars. The resistance levels of the cultivars were thus classified into classes I, II, III and IV interpreted as ‘very susceptible’, ‘susceptible’, ‘moderately slow blighting’ and ‘slow blighting’, respectively. All the late maturity cultivars were classified as class IV, and the earlier maturing cultivars were either class I or class II.

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“…), Magnum Bonum (Early blight disease resistant; Odilbekov et al . ) and SW93‐1015 (breeding clone in the Swedish breeding programme for late blight resistance; Ali et al . , ) were provided by Ulrika Nilsson, SLU, Alnarp, Sweden.…”

Section: Methodsmentioning

confidence: 99%

Salicylic and jasmonic acid pathways are necessary for defence against Dickeya solani as revealed by a novel method for Blackleg disease screening of in vitro grown potato

2015

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Potato is major crop ensuring food security in Europe, and blackleg disease is increasingly causing losses in yield and during storage. Recently, one blackleg pathogen, Dickeya solani has been shown to be spreading in Northern Europe that causes aggressive disease development. Currently, identification of tolerant commercial potato varieties has been unsuccessful; this is confounded by the complicated etiology of the disease and a strong environmental influence on disease development. There is currently a lack of efficient testing systems. Here, we describe a system for quantification of blackleg symptoms on shoots of sterile in vitro potato plants, which saves time and space compared to greenhouse and existing field assays. We found no evidence for differences in infection between the described in vitro-based screening method and existing greenhouse assays. This system facilitates efficient screening of blackleg disease response of potato plants independent of other microorganisms and variable environmental conditions. We therefore used the in vitro screening method to increase understanding of plant mechanisms involved in blackleg disease development by analysing disease response of hormone- related (salicylic and jasmonic acid) transgenic potato plants. We show that both jasmonic (JA) and salicylic (SA) acid pathways regulate tolerance to blackleg disease in potato, a result unlike previous findings in Arabidopsis defence response to necrotrophic bacteria. We confirm this by showing induction of a SA marker, pathogenesis-related protein 1 (StPR1), and a JA marker, lipoxygenase (StLOX), in Dickeya solani infected in vitro potato plants. We also observed that tubers of transgenic potato plants were more susceptible to soft rot compared to wild type, suggesting a role for SA and JA pathways in general tolerance to Dickeya.

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Phenotyping early blight resistance in potato cultivars and breeding clones

Cited by 31 publications

References 34 publications

Genetic diversity and occurrence of the F129L substitutions among isolates of Alternaria solani in south-eastern Sweden

Genetic diversity and occurrence of the F129L substitutions among isolates of Alternaria solani in south-eastern Sweden

Resistance status of cultivated potatoes to early blight (Alternaria solani) in Denmark

Salicylic and jasmonic acid pathways are necessary for defence against Dickeya solani as revealed by a novel method for Blackleg disease screening of in vitro grown potato

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