A reproducible assay for measuring partial resistance to Sclerotinia sclerotiorum in soybean

2012 ◽  
Vol 92 (2) ◽  
pp. 279-288 ◽  
Author(s):  
Maxime Bastien ◽  
Tung Thanh Huynh ◽  
Geneviève Giroux ◽  
Elmer Iquira ◽  
Sylvie Rioux ◽  
...  
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Partial Resistance ◽  
Recombinant Inbred Lines ◽  
Natural Infection ◽  
Reference Method ◽  
Main Stem ◽  
Stem Rot ◽  
Lesion Length ◽  
Sclerotinia Stem Rot ◽  
Eastern Canada

Bastien, M., Huynh, T. T., Giroux, G., Iquira, E., Rioux, S. and Belzile, F. 2012. A reproducible assay for measuring partial resistance to Sclerotinia sclerotiorum in soybean. Can. J. Plant Sci. 92: 279–288. In eastern Canada, Sclerotinia stem rot in soybean is an important disease, and resistance is systematically assessed in cultivar performance trials. The reference method used in these trials closely mimics the natural infection process, but is very demanding, and its success is highly subject to environmental conditions. Here we describe a simple, quick and reproducible inoculation method to measure resistance to pathogen progression on the main stem. Importantly, this method is the first to reproducibly identify quantitative trait loci (QTLs) conferring partial resistance to Sclerotinia stem rot in soybean. In this method, a cotton pad saturated with a mycelial suspension is applied to a floral bud and resistance is estimated by measuring lesion length on the main stem. The method was found to discriminate clearly between known resistant and susceptible checks in both the field and greenhouse. Clear discrimination between 26 recombinant inbred lines (RILs) contrasted for QTLs controlling resistance to Sclerotinia stem rot was also achieved in four independent trials, and lesion length was significantly correlated among all trials. When tested on 38, 42 and 40 lines in registration trials, the results of this method were significantly correlated with those of the reference method in 2 of 3 yr.

Development of a new field inoculation technique to assess partial resistance in soybean to Sclerotinia sclerotiorum

2004 ◽  
Vol 84 (1) ◽  
pp. 57-64 ◽  
Author(s):  
J. Auclair ◽  
G. J. Boland ◽  
E. Cober ◽  
G. L. Graef ◽  
J. R. Steadman ◽  
...  
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Partial Resistance ◽  
Natural Infection ◽  
Severity Index ◽  
Stem Rot ◽  
Sclerotinia Stem Rot ◽  
Field Inoculation ◽  
Inoculation Technique ◽  
White Mould ◽  
Barley Kernel

The use of appropriate techniques to assess disease resistance is crucial to understanding the genetic control of host resistance to pathogens to develop resistant plant varieties. The objective of this study was to develop and evaluate a novel field-based inoculation technique for sclerotinia stem rot in soybean [Glycine max (L.) Merr.], caused by Sclerotinia sclerotiorum (Lib.) de Bary. The barley kernel inoculation technique involves stem inoculation using an infected barley kernel inserted into a wound made in the soybean stem. The damage on soybean plants is measured by the length of the lesion on inoculated stem and expressed as inoculation severity index (ISI). Soybean varieties were evaluated for 2 yr at different sites using the barley kernel inoculation technique, and compared with other controlled environment and natural infection-based techniques. The ISIs obtained at Elora, ON, were significantly correlated (r = 0.21, P = 0.021) between the 2 test years (1998 and 1999), and in 1998 with natural infection [as measured by the disease severity index, DSI] at the same location (r = 0.31; P = 0.0005). Using a small set of lines that were specifically selected over several years to respond to DSI, the correlation between the DSI from some locations and years and the ISI in 1999 was negative. The significant positive correlations obtained using soybean lines that were not previously selected for DSI suggest the potential of this technique for pre-screening the breeding material for partial resistance to sclerotinia stem rot prior to confirmation with natural infection levels as measured by DSI. This may be of value to soybean breeders trying to develop soybean lines partially resistant to sclerotinia stem rot because of the difficulty in obtaining consistent and reliable DSI scores across locations and over years. Key words: Sclerotinia stem rot, white mould, inoculation, resistance, soybean

scholarly journals Genetic analysis of partial resistance to basal stem rot (Sclerotinia sclerotiorum) in sunflower

Genetika ◽  
2013 ◽  
Vol 45 (3) ◽  
pp. 737-748 ◽  
Author(s):  
Masoumeh Amouzadeh ◽  
Reza Darvishzadeh ◽  
Parham Haddadi ◽  
Mandoulakani Abdollahi ◽  
Danesh Rezaee
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Partial Resistance ◽  
Recombinant Inbred Lines ◽  
Interval Mapping ◽  
Stem Rot ◽  
Phenotypic Variance ◽  
Basal Stem Rot ◽  
Paternal Line ◽  
Randomized Design ◽  
Parental Lines

Basal stem rot, caused by Sclerotinia sclerotiorum (Lib.) de Bary, is one of the major diseases of sunflower (Helianthus annuus L.) in the world. Quantitative trait loci (QTLs) implicated in partial resistance to basal stem rot disease were identified using 99 recombinant inbred lines (RILs) from the cross between sunflower parental lines PAC2 and RHA266. The study was undertaken in a completely randomized design with three replications under controlled conditions. The RILs and their parental lines were inoculated with a moderately aggressive isolate of S. sclerotiorum (SSKH41). Resistance to disease was evaluated by measuring the percentage of necrosis area three days after inoculation. QTLs were mapped using an updated high-density SSR and SNP linkage map. ANOVA showed significant differences among sunflower lines for resistance to basal stem rot (P?0.05). The frequency distribution of lines for susceptibility to disease showed a continuous pattern. Composite interval mapping analysis revealed 5 QTLs for percentage of necrotic area, localized on linkage groups 1, 3, 8, 10 and 17. The sign of additive effect was positive in 5 QTLs, suggesting that the additive allele for partial resistance to basal stem rot came from the paternal line (RHA266). The phenotypic variance explained by QTLs (R2) ranged from 0.5 to 3.16%. Identified genes (HUCL02246_1, GST and POD), and SSR markers (ORS338, and SSL3) encompassing the QTLs for partial resistance to basal stem rot could be good candidates for marker assisted selection.

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.

Expression of field resistance under Western Australian conditions to Sclerotinia sclerotiorum in Chinese and Australian Brassica napus and Brassica juncea germplasm and its relation with stem diameter

2006 ◽  
Vol 57 (10) ◽  
pp. 1131 ◽  
Author(s):  
C. X. Li ◽  
Hua Li ◽  
K. Sivasithamparam ◽  
T. D. Fu ◽  
Y. C. Li ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Brassica Juncea ◽  
Sclerotinia Sclerotiorum ◽  
Stem Diameter ◽  
Stem Rot ◽  
Lesion Length ◽  
Sclerotinia Stem Rot ◽  
Sources Of Resistance ◽  
Stem Lesion ◽  
Western Australian

Sclerotinia stem rot, caused by Sclerotinia sclerotiorum, has become one of the most serious disease problems in oilseed rape-growing areas in Australia. Sources of resistance to this disease have been sought worldwide. In this study, germplasm comprising 42 Brassica napus and 12 Brassica juncea accessions from China and Australia, was screened for resistance to Sclerotinia stem rot under Western Australian field conditions. Resistance was confirmed in some germplasm from China and new sources of resistance were identified in germplasm from Australia. Furthermore, our study found that the severity of stem lesions was related to stem diameter and percentage of the host plants that were dead. It was evident that both stem lesion length and percentage of plant death were at the lowest level when the stem diameter was approximately 10 mm. Smaller or greater stem diameter resulted both in increased stem lesion length and plant death. Stem diameter may be a useful parameter in breeding cultivars of oilseed Brassicas with Sclerotinia resistance.

Prevalence of sclerotinia stem rot of canola in New South Wales

2003 ◽  
Vol 43 (2) ◽  
pp. 163 ◽  
Author(s):  
T. L. Hind ◽  
G. J. Ash ◽  
G. M. Murray
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
New South ◽  
New South Wales ◽  
Stem Rot ◽  
Sclerotinia Stem Rot ◽  
Mean Values ◽  
Stem Infection ◽  
South Wales

Surveys of petal infestation and stem infection conducted in 1998, 1999 and 2000 indicated that Sclerotinia sclerotiorum poses a threat to the Australian canola industry. Inoculum was present throughout all canola-growing regions of New South Wales and the stem disease was widespread throughout southern New South Wales. Percentage petal infestation increased over the 3 years surveyed with values ranging from 0 to 99.4%. The highest petal infestation values were observed in 2000 (maximum of 99.4%, mean of 82.2%), with lower mean values in 1998 (38.4%) and 1999 (49.6%). Stem infection ranged from 0 to 37.5% and most fields had less than 10% stem infection. Stem rot incidence before harvest did not relate to percentage petal infestation determined during flowering. This indicated that factors other than percentage petal infestation were important in influencing stem rot incidence. While there was no relationship between percentage petal infestation and stem rot incidence, stem infection never occurred without prior petal infestation.

Nitrogen management strategies on plant growth and severities of Sclerotinia stem rot of canola in eastern Canada

2021 ◽  
Author(s):  
Fen Gao ◽  
Yuanhong Chen ◽  
SeaRa Lim ◽  
Allen Xue ◽  
Bao-Luo Ma
Keyword(s):  
Plant Growth ◽  
Seed Yield ◽  
Management Strategies ◽  
Stem Rot ◽  
Sclerotinia Stem Rot ◽  
Split Application ◽  
Eastern Canada ◽  
N Application ◽  
Application Rates ◽  
N Management

Effective nitrogen (N) management strategies are important for ensuring a balance between optimizing plant growth and minimizing disease damage. A field experiment was conducted for three years to (i) assess the effects of N fertilizer application on the growth and seed yield of canola, and severities of Sclerotinia stem rot (SSR), and (ii) determine a reasonable N-rate for optimizing plant growth and minimizing the loss from SSR in eastern Canada. The experiment was designed with factorial combinations of eight N treatments and two canola hybrids. All N-treatments reduced canola emergence with increasing preplant N application rates above 100 kg ha–1, but had a positive impact on plant height, fresh weight, dry weight and seed yield. The development of SSR showed differential responses to N application rates. Of all the treatments, the split application (50 kg N ha–1 at preplant plus 100 kg N ha–1 side-dressed at the 6-leaf stage) increased canola growth, and often produced the highest or similar seed yields to those of equivalent N rate applied as preplant. At the 150 kg ha–1 N rate, no severe development of SSR was observed in either preplant-only or split application. Overall, this study demonstrates that the split-N management strategy (50+100 kg ha–1) maintained a balance between enhancing plant growth and mitigating the negative impacts of SSR on canola.

scholarly journals Favorable Bioactivity of the SDHI Fungicide Benzovindiflupyr Against Sclerotinia sclerotiorum Mycelial Growth, Sclerotial Production, and Myceliogenic and Carpogenic Germination of Sclerotia

Plant Disease ◽  
2019 ◽  
Vol 103 (7) ◽  
pp. 1613-1620 ◽  
Author(s):  
Xue-ping Huang ◽  
Jian Luo ◽  
Yu-fei Song ◽  
Bei-xing Li ◽  
Wei Mu ◽  
...  
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Mycelial Growth ◽  
Disease Incidence ◽  
Stem Rot ◽  
Sclerotinia Stem Rot ◽  
Baseline Sensitivity ◽  
Carpogenic Germination ◽  
Alternative Product ◽  
Application Potential ◽  
New Generation

Sclerotinia sclerotiorum, which can cause Sclerotinia stem rot, is a prevalent plant pathogen. This study aims to evaluate the application potential of benzovindiflupyr, a new generation of succinate dehydrogenase inhibitor (SDHI), against S. sclerotiorum. In our study, 181 isolates collected from different crops (including eggplant [n = 34], cucumber [n = 27], tomato [n = 29], pepper [n = 35], pumpkin [n = 32], and kidney bean [n = 25]) in China were used to establish baseline sensitivity to benzovindiflupyr. The frequency distribution of the 50% effective concentration (EC50) values of benzovindiflupyr was a unimodal curve, with mean EC50 values of 0.0260 ± 0.011 μg/ml, and no significant differences in mean EC50 existed among the various crops (P > 0.99). Benzovindiflupyr can effectively inhibit mycelial growth, sclerotial production, sclerotial shape, and myceliogenic and carpogenic germination of the sclerotia of S. sclerotiorum. In addition, benzovindiflupyr showed good systemic translocation in eggplant. Using benzovindiflupyr at 100 μg/ml yielded efficacies of 71.3 and 80.5% for transverse activity and cross-layer activity, respectively, which were higher than those of acropetal and basipetal treatments (43.6 and 44.7%, respectively). Greenhouse experiments were then carried out at two experimental sites for verification. Applying benzovindiflupyr at 200 g a.i. ha−1 significantly reduced the disease incidence and severity of Sclerotinia stem rot. Overall, the results demonstrated that benzovindiflupyr is a potential alternative product to control Sclerotinia stem rot.

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