scholarly journals Efficacy of Fungicides for Control of Sclerotinia Stem Rot of Canola

Plant Disease ◽  
2006 ◽  
Vol 90 (9) ◽  
pp. 1129-1134 ◽  
Author(s):  
C. A. Bradley ◽  
H. A. Lamey ◽  
G. J. Endres ◽  
R. A. Henson ◽  
B. K. Hanson ◽  
...  
Keyword(s):  
Brassica Napus ◽  
North Dakota ◽  
Sclerotinia Sclerotiorum ◽  
Untreated Control ◽  
Field Trials ◽  
Stem Rot ◽  
Sclerotinia Stem Rot ◽  
Application Timing ◽  
Thiophanate Methyl

Sclerotinia stem rot (SSR), incited by Sclerotinia sclerotiorum, causes yield reductions to canola (Brassica napus) grown in North Dakota and Minnesota. Field trials were conducted in North Dakota and Minnesota from 2000 to 2004 to evaluate the effect of foliar fungicides on SSR and canola yield. Levels of SSR varied among years and location. In general, fungicides that consistently reduced SSR incidence compared with an untreated control were azoxystrobin, benomyl, boscalid, iprodione, prothioconazole, tebuconazole, thiophanate-methyl, trifloxystrobin, and vinclozolin. Significant reductions in SSR incidence with fungicides did not always translate into differences in canola yield, however. Inconsistent results were observed with different timings of applications based on percent bloom. This indicates that application timing should be based on factors in addition to percent bloom.

scholarly journals Effects of the Novel Fungicide Benzothiostrobin on Sclerotinia sclerotiorum in the Laboratory and on Sclerotinia Stem Rot in Rape Fields

Plant Disease ◽  
2015 ◽  
Vol 99 (7) ◽  
pp. 969-975 ◽  
Author(s):  
Congying Xu ◽  
Xiaoyu Liang ◽  
Yiping Hou ◽  
Mingguo Zhou
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Pathogenic Fungus ◽  
Field Trials ◽  
Stem Rot ◽  
Cross Resistance ◽  
Synergistic Activity ◽  
The Novel ◽  
Sclerotinia Stem Rot ◽  
Sclerotial Germination

We determined the effects and efficacy of benzothiostrobin, a new strobilurin-derived fungicide, against the plant-pathogenic fungus Sclerotinia sclerotiorum (the causal agent of Sclerotinia stem rot). Mycelial growth and sclerotial germination in vitro were strongly inhibited by benzothiostrobin in the presence of salicylhydroxamic acid. On detached rapeseed leaves, benzothiostrobin at 40 μg/ml reduced lesion development by 87%. No cross-resistance was detected between benzothiostrobin and carbendazim, iprodione, fludioxonil, or boscalid. A formulated mixture of benzothiostrobin and fluazinam at 1:1 had synergistic activity against S. sclerotiorum in vitro. In field trials, benzothiostrobin alone or formulated with fluazinam at 1:1 (150 g a.i. ha−1) was significantly (P < 0.05) superior to iprodione in controlling Sclerotinia stem rot of rapeseed. These results suggest that benzothiostrobin has substantial potential for the control of Sclerotinia stem rot.

scholarly journals Response of Canola Cultivars to Sclerotinia sclerotiorum in Controlled and Field Environments

Plant Disease ◽  
2006 ◽  
Vol 90 (2) ◽  
pp. 215-219 ◽  
Author(s):  
C. A. Bradley ◽  
R. A. Henson ◽  
P. M. Porter ◽  
D. G. LeGare ◽  
L. E. del Río ◽  
...  
Keyword(s):  
United States ◽  
Sclerotinia Sclerotiorum ◽  
Disease Process ◽  
Field Trials ◽  
Stem Rot ◽  
Sclerotinia Stem Rot ◽  
Detached Leaf ◽  
Red Lake ◽  
Low Levels ◽  
Northern United States

Sclerotinia stem rot (SSR), caused by Sclerotinia sclerotiorum, can be a devastating disease of canola (Brassica napus) in the northern United States. No canola cultivars are marketed as having resistance to SSR. Field trials were established in Red Lake Falls, MN (2001, 2003, and 2004) and Carrington, ND (2001, 2002, 2003, and 2004) to evaluate canola cultivars for resistance to SSR. These cultivars also were evaluated for resistance to SSR under controlled conditions using the following methods: petiole inoculation technique (PIT), detached leaf assay (DLA), and oxalic acid assay (OAA). Significant (P ≤ 0.05) differences were detected among cultivars for SSR and yield in the field trials, with SSR levels varying from low to high among years and locations. Cultivars with consistent high levels and low levels of SSR in the field trials were identified. Significant (P ≤ 0.05) differences were detected among cultivars for SSR using the PIT and OAA methods, but not the DLA method. No significant (P ≤ 0.05) correlations between SSR levels in the controlled studies with SSR levels in the field trials were detected; however, significant negative correlations were detected between SSR area under the disease process curve values from the PIT method and yield from Carrington, ND in 2001 and 2002. Although the PIT and OAA methods differentiated cultivars, neither method was able to predict the reaction of cultivars to SSR in the field, indicating that field screening for SSR resistance is still critical for the development of resistant cultivars.

Lignin composition and timing of cell wall lignification are involved in Brassica napus resistance to Sclerotinia sclerotiorum stem rot

2021 ◽  
Author(s):  
Andreas von Tiedemann ◽  
Birger Koopmann ◽  
Kerstin Hoech
Keyword(s):  
Cell Wall ◽  
Brassica Napus ◽  
Sclerotinia Sclerotiorum ◽  
Plant Defence ◽  
Phenylpropanoid Pathway ◽  
Stem Rot ◽  
Phenylpropanoid Metabolism ◽  
Sclerotinia Stem Rot ◽  
Cell Wall Modification ◽  
Lignin Deposition

Sclerotinia stem rot (SSR) is an economically and globally significant disease in oilseed rape (Brassica napus L.) caused by the necrotrophic ascomycete Sclerotinia sclerotiorum. This study explored the role of cell wall reinforcement by lignin as a relevant factor for effective plant defence against attack of this pathogen. Expression of key genes in the phenylpropanoid pathway and the induced synthesis of lignin in infected stem tissues were investigated in a study comparing a susceptible (Loras) and a moderately resistant cultivar (Zhongyou 821, ZY821). Data revealed an earlier and more rapid defence activation in ZY821 through up-regulation of transcript levels of genes related to key steps in the phenylpropanoid pathway associated with enhanced lignin deposition in the resistant B. napus genotype. Expression level of BnCAD5, encoding a cinnamyl alcohol dehydrogenase, responsible for conversion of monolignol to lignin, was more rapidly up-regulated in ZY821 than Loras. The similar expression pattern of BnCAD5 and the gene BnF5H, encoding for the ferulate-5-hydroxylase which catalyses the synthesis of syringyl (S) lignin precursors, suggests that BnCAD5 is involved in the S lignin formation. Histological observations confirmed these results, showing an earlier increase of S lignin deposition in the infected resistant genotype. Deposition of guaiacyl (G) lignin was detected in both genotypes and is thus considered a component of basal, cultivar-independent defence response of B. napus to stem rot. The results indicate the importance of cell wall modification for quantitative stem rot resistance by responses in the phenylpropanoid metabolism generating distinct lignin types on different temporal scales.

scholarly journals First Report of Sclerotinia Stem Rot of Chickpea Caused by Sclerotinia sclerotiorum in North Dakota and Washington

Plant Disease ◽  
2006 ◽  
Vol 90 (1) ◽  
pp. 114-114 ◽  
Author(s):  
W. Chen ◽  
B. Schatz ◽  
B. Henson ◽  
K. E. McPhee ◽  
F. J. Muehlbauer
Keyword(s):  
North Dakota ◽  
Sclerotinia Sclerotiorum ◽  
Disease Incidence ◽  
Ascochyta Blight ◽  
Growing Season ◽  
Stem Rot ◽  
Sclerotinia Stem Rot ◽  
Internal Transcribed Spacer Region ◽  
First Report ◽  
Stem Breakage

Chickpea (Cicer arietinum L.) is cultivated as a rotational crop in the cereal-based production system in the U.S. Pacific Northwest (PNW) and its production is expanding to other northern tier states. During July 2005, symptoms of Sclerotinia stem rot were observed on chickpea cv. Dwelley and Dylan in fields near Spangle, WA and Carrington, ND, respectively, with disease incidence of approximately ≤1% in affected areas at both locations. Symptoms included stem whitening, wilting, and stem breakage. Occasionally, white fluffy mycelium was observed; however, production of sclerotia on infected plants was rarely observed. Sclerotinia sclerotiorum was isolated from diseased stems collected from both states. The isolates produced a ring of sclerotia near the edge of potato dextrose agar (PDA) plates in 7 days and produced neither conidia nor other fruiting bodies in culture after 30 days. PCR amplification of the rDNA internal transcribed spacer region from two representative isolates and subsequent digestion with restriction enzymes, Mbo I and Taq I, produced identical banding patterns to previously identified isolates of S. sclerotiorum from pea from the PNW (2). Chickpea cvs. Dwelley and Spanish White (eight plants of each) were inoculated by fastening mycelial agar plugs from an actively growing colony on PDA onto the stems with Parafilm. Symptoms of stem whitening were observed as early as 2 days after inoculation, and the lesions extended upward and downward from the inoculation site. Wilting and stem breakage were also observed. Control inoculations of four plants of each cultivar with PDA plugs without mycelium produced no visible symptoms. S. sclerotiorum was consistently reisolated from inoculated plants but not from control plants. Chickpea had been grown in the PNW for more than 20 years without any reported incidence of Sclerotinia stem rot although the disease has been reported from Arizona (3) and Asian countries (1). This is likely because of the upright growth habit of the chickpea plant coupled with relatively dry conditions late in the growing season. Previous chickpea cultivars were very susceptible to Ascochyta blight, an early-season disease of chickpea in the PNW that reduced chickpea stands and canopy coverage. Current cultivars possess much improved resistance to Ascochyta blight, allowing greater vegetative growth to occur and creating microenvironmental conditions conducive to Sclerotinia stem rot. In North Dakota, where humid conditions prevail late in the growing season, symptoms of Sclerotinia stem rot had been observed in previous years but had not been documented because of a recent history of chickpea cultivation there. To our knowledge, this is the first report of confirmed Sclerotinia stem rot of chickpea in North Dakota and Washington. References: (1) G. J. Boland and R. Hall. Can. J. Plant Pathol. 16:93, 1994. (2) I. Jimenez-Hidalgo et al. Phytopathology (Abstr.) 94(suppl.):S47, 2004. (3) M. E. Matheron and M. Porchas. Plant Dis. 84:1250, 2000.

Identification of Brassica napus Lines with Partial Resistance to Sclerotinia sclerotiorum

2011 ◽  
Vol 12 (1) ◽  
pp. 15 ◽  
Author(s):  
S. D. Khot ◽  
V. N. Bilgi ◽  
L. E. del Río ◽  
C. A. Bradley
Keyword(s):  
Brassica Napus ◽  
Sclerotinia Sclerotiorum ◽  
Partial Resistance ◽  
Plant Introduction ◽  
Field Resistance ◽  
Causal Agent ◽  
Stem Rot ◽  
Sclerotinia Stem Rot ◽  
Breeding Programs ◽  
Research Studies

A collection of Brassica napus plant introduction (PI) lines was evaluated in a series of research trials to identify lines with resistance to Sclerotinia sclerotiorum, causal agent of Sclerotinia stem rot of canola. Five PI lines (169080, 286418, 436554, 458940, and 633119) were identified that consistently had SSR resistance levels equal to or greater than the partially resistant check cultivar Hyola 357. In addition, two of these lines (436554 and 458940) were found to exhibit SSR field resistance levels similar to Hyola 357. The PI lines identified from our research studies could be used in canola breeding programs to develop cultivars with improved resistance to S. sclerotiorum. Accepted for publication 21 February 2011. Published 22 April 2011.

scholarly journals Efficacy of Fungicides on Sclerotinia sclerotiorum and Their Potential for Control of Sclerotinia Stem Rot on Soybean

Plant Disease ◽  
2002 ◽  
Vol 86 (1) ◽  
pp. 26-31 ◽  
Author(s):  
D. S. Mueller ◽  
A. E. Dorrance ◽  
R. C. Derksen ◽  
E. Ozkan ◽  
J. E. Kurle ◽  
...  
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Radial Growth ◽  
Disease Incidence ◽  
Leaf Tissue ◽  
The United States ◽  
Stem Rot ◽  
Sclerotinia Stem Rot ◽  
Thiophanate Methyl ◽  
Application Systems

Sclerotinia stem rot of soybean, caused by Sclerotinia sclerotiorum, is a major disease in the north central region of the United States. One approach to managing Sclerotinia stem rot on soybean is the use of fungicides. S. sclerotiorum was assayed for sensitivity to benomyl, tebuconazole, thiophanate methyl, and vinclozolin in pure cultures on agar medium, inoculated soybean seedlings, detached inoculated leaves, and in experimental field plots. To evaluate the inhibitory effect of four fungicides on growth of S. sclerotiorum in vitro, potato dextrose agar (PDA) was amended with the fungicides at six concentrations. Based on measurements of fungal radial growth, vinclozolin was the most effective in inhibiting S. sclerotiorum mycelial growth at 1.0 μg a.i./ml of PDA. Ranges of reduction of radial growth of 91 isolates of S. sclerotiorum on PDA amended with thiophanate methyl and vinclozolin were 18 to 93% and 93 to 99%, respectively, when compared with the nonamended agar control. Benomyl, thiophanate methyl, and vinclozolin applied to greenhouse-grown seedlings prevented S. sclerotiorum from expressing symptoms or signs on leaf tissue. Detached leaves sprayed with thiophanate methyl and then inoculated with mycelial plugs of S. sclerotiorum did not express symptoms or signs. Of 13 different environments in Illinois, Indiana, Ohio, and Wisconsin from 1995 through 2000, six had low Sclerotinia stem rot incidence (<1%), three environments had low to moderate Sclerotinia stem rot incidence (5 to 25%), and four environments had high Sclerotinia stem rot incidence (>25%). When disease incidence was high, no consistent control of Sclerotinia stem rot was observed with benomyl or thiophanate methyl using different application systems. However, under low disease incidence, spray systems that were able to penetrate the canopy reduced the incidence of Sclerotinia stem rot an average of 50%.

scholarly journals A Quantitative PCR System for Measuring Sclerotinia sclerotiorum in Canola (Brassica napus)

Plant Disease ◽  
2016 ◽  
Vol 100 (5) ◽  
pp. 984-990 ◽  
Author(s):  
B. R. Ziesman ◽  
T. K. Turkington ◽  
U. Basu ◽  
S. E. Strelkov
Keyword(s):  
Risk Assessment ◽  
Brassica Napus ◽  
Sclerotinia Sclerotiorum ◽  
Assessment Tool ◽  
Quantitative Polymerase Chain Reaction ◽  
Qpcr Assay ◽  
Stem Rot ◽  
Specific Gene ◽  
Sclerotinia Stem Rot ◽  
Hydrolysis Probe

Sclerotinia stem rot, caused by Sclerotinia sclerotiorum, is an economically important disease of canola (Brassica napus) commonly managed by routine application of fungicides. Petal infestation has been demonstrated to be an important stage of the disease cycle in canola and has been the focus of previously developed Sclerotinia stem rot risk assessment methods. Quantitative polymerase chain reaction (qPCR) analysis can provide a more rapid and accurate assessment of petal infestation levels. Primers and a hydrolysis probe were designed to amplify a 70-bp region of an S. sclerotiorum-specific gene, SS1G_00263. A hydrolysis probe-based qPCR assay was developed that had a detection limit of 8.0 × 10−4 ng of S. sclerotiorum DNA and only amplified S. sclerotiorum DNA. Evaluation of petals collected at five sampling points in each of 10 commercial canola fields on each of two sampling dates (corresponding to 20 to 30% bloom and 40 to 50% bloom) revealed S. sclerotiorum DNA infestation levels of 0 to 3.3 × 10−1 ng/petal. This qPCR assay can be used to reliably quantify petal infestation and, with further research, has the potential to serve as the basis for a Sclerotinia stem rot risk assessment tool or as a means to study Sclerotinia stem rot epidemiology.

scholarly journals Transcriptome Analysis Reveals the Complex Molecular Mechanisms of Brassica napus–Sclerotinia sclerotiorum Interactions

2021 ◽  
Vol 12 ◽  
Author(s):  
Binjie Xu ◽  
Xi Gong ◽  
Song Chen ◽  
Maolong Hu ◽  
Jiefu Zhang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Brassica Napus ◽  
Sclerotinia Sclerotiorum ◽  
Molecular Mechanisms ◽  
Hydrolytic Enzymes ◽  
Infection Process ◽  
Stem Rot ◽  
Post Inoculation ◽  
Sclerotinia Stem Rot ◽  
Acid Pathway

Sclerotinia stem rot caused by Sclerotinia sclerotiorum is a devastating disease for many important crops worldwide, including Brassica napus. Although numerous studies have been performed on the gene expression changes in B. napus and S. sclerotiorum, knowledge regarding the molecular mechanisms of B. napus–S. sclerotiorum interactions is limited. Here, we revealed the changes in the gene expression and related pathways in both B. napus and S. sclerotiorum during the sclerotinia stem rot (SSR) infection process using transcriptome analyses. In total, 1,986, 2,217, and 16,079 differentially expressed genes (DEGs) were identified in B. napus at 6, 24, and 48 h post-inoculation, respectively, whereas 1,511, 1,208, and 2,051 DEGs, respectively, were identified in S. sclerotiorum. The gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses showed that most of the hormone-signaling pathways in B. napus were enriched, and thus, the hormone contents at four stages were measured. The DEGs and hormone contents revealed that salicylic acid was activated, while the jasmonic acid pathway was repressed at 24 h post-inoculation. Additionally, the expressional patterns of the cell wall-degrading enzyme-encoding genes in S. sclerotiorum and the hydrolytic enzymes in B. napus were consistent with the SSR infection process. The results contribute to a better understanding of the interactions between B. napus and S. sclerotiorum and the development of future preventive measures against SSR.

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