The importance of the type and time of inoculation and assessment in the determination of resistance in Brassia napus and B. juncea to Sclerotinia sclerotiorum

Sclerotinia stem rot (SSR) is a significant agricultural problem worldwide. Finding sources of resistance is crucial to the ongoing search for better management of this disease. Brassica germplasm from Australia, China and India was screened for resistance to SSR under Western Australian field conditions following stem inoculation, application of a spray of mycelial suspension, or as a consequence of myceliogenic germination originating from sclerotia resident in soil. Significant differences in response were observed among 53 genotypes using each of the three screening methods. There was a variable impact of the time of inoculation on the disease level depending upon time of assessment post-stem inoculation. However, this impact could be reduced to an insignificant level provided the assessment after stem inoculation was delayed until 3 weeks post-inoculation. The results of these studies indicate that the use of appropriate inoculation and assessment methods could significantly reduce variability in the responses commonly observed in screening for resistance in crop plants against Sclerotinia sclerotiorum.

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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

Australian Journal of Agricultural Research ◽

10.1071/ar06066 ◽

2006 ◽

Vol 57 (10) ◽

pp. 1131 ◽

Cited By ~ 47

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.

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Efficacy of three greenhouse screening methods for the identification of physiological resistance to white mold in dry bean

Canadian Journal of Plant Science ◽

10.4141/cjps08230 ◽

2009 ◽

Vol 89 (4) ◽

pp. 755-762 ◽

Cited By ~ 11

Author(s):

H Terán ◽

S P Singh

Keyword(s):

Phaseolus Vulgaris ◽

Common Bean ◽

Sclerotinia Sclerotiorum ◽

Screening Method ◽

White Mold ◽

Screening Methods ◽

Post Inoculation ◽

Dry Bean ◽

Physiological Resistance ◽

Nueva Granada

White mold (WM) caused by Sclerotinia sclerotiorum (Lib.) de Bary is the most devastating disease of common bean (dry and snap or garden bean) (Phaseolus vulgaris L.) in North America. The use of a reliable screening method (SM) in common bean is crucial to improve physiological resistance to WM. The objective of this study was to compare the efficacy of three SM to identify physiological resistance in dry bean genotypes with different evolutionary origins and levels of resistance. Screening methods tested were: (i) the modified straw test or cut–stem (CSM); (ii) infected bean flower (IFL); and (iii) infected oat seed (IOS). A 195, ICA Bunsi, Othello, and VCW 54 dry bean were tested with the three SM. The experimental design was a split plot in randomized complete blocks with three replications in 2007 and 2008. Two independent inoculations 1 wk apart for each SM were made. The WM reaction was scored at 16, 23, and 33 d post-inoculation (DPI) using a 1 to 9 scale. There were highly significant differences between SM and its interaction with years. The CSM and IFL were the most consistent and highly correlated (r > 0.70, P < 0.01). Interspecific breeding line VCW 54 consistently had the highest WM resistance across years, SM, and evaluation dates, followed by A 195. White mold scores increased with delayed evaluations. Thus, CSM or IFL with disease assessed 33 DPI should be used for identifying common bean genotypes with high levels of physiological resistance to WM.Key words: Common bean, growth habit, race Mesoamerica, race Nueva Granada, Phaseolus vulgaris, Sclerotinia sclerotiorum

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New sources of resistance to Sclerotinia stem rot caused bySclerotinia sclerotiorumin Chinese and AustralianBrassica napusandB. junceagermplasm screened under Western Australian conditions

Australasian Plant Pathology ◽

10.1071/ap08087 ◽

2009 ◽

Vol 38 (2) ◽

pp. 149 ◽

Cited By ~ 38

Author(s):

C. X. Li ◽

S. Y. Liu ◽

K. Sivasithamparam ◽

M. J. Barbetti

Keyword(s):

Stem Rot ◽

Sclerotinia Stem Rot ◽

Sources Of Resistance ◽

Western Australian

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Comparative transcriptomic analysis uncovers the complex genetic network for resistance to Sclerotinia sclerotiorum in Brassica napus

Scientific Reports ◽

10.1038/srep19007 ◽

2016 ◽

Vol 6 (1) ◽

Cited By ~ 56

Author(s):

Jian Wu ◽

Qing Zhao ◽

Qingyong Yang ◽

Han Liu ◽

Qingyuan Li ◽

...

Keyword(s):

Brassica Napus ◽

Differentially Expressed Genes ◽

Sclerotinia Sclerotiorum ◽

Defense Response ◽

Quantitative Resistance ◽

Resistance Breeding ◽

Mapk Signaling ◽

Differentially Expressed ◽

Post Inoculation ◽

Sclerotinia Stem Rot

Abstract Sclerotinia stem rot caused by Sclerotinia sclerotiorum is one of the most devastating diseases in many important crops including Brassica napus worldwide. Quantitative resistance is the only source for genetic improvement of Sclerotinia-resistance in B. napus, but the molecular basis for such a resistance is largely unknown. Here, we performed dynamic transcriptomic analyses to understand the differential defense response to S. sclerotiorum in a resistant line (R-line) and a susceptible line (S-line) of B. napus at 24, 48 and 96 h post-inoculation. Both the numbers of and fold changes in differentially expressed genes in the R-line were larger than those in the S-line. We identified 9001 relative differentially expressed genes in the R-line compared with the S-line. The differences between susceptibility and resistance were associated with the magnitude of expression changes in a set of genes involved in pathogen recognition, MAPK signaling cascade, WRKY transcription regulation, jasmonic acid/ethylene signaling pathways and biosynthesis of defense-related protein and indolic glucosinolate. The results were supported by quantitation of defense-related enzyme activity and glucosinolate contents. Our results provide insights into the complex molecular mechanism of the defense response to S. sclerotiorum in B. napus and for development of effective strategies in Sclerotinia-resistance breeding.

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

Frontiers in Plant Science ◽

10.3389/fpls.2021.716935 ◽

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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Seedling Resistance to Sclerotinia sclerotiorum as Expressed Across Diverse Cruciferous Species

Plant Disease ◽

10.1094/pdis-06-13-0612-re ◽

2014 ◽

Vol 98 (2) ◽

pp. 184-190 ◽

Cited By ~ 24

Author(s):

Margaret Uloth ◽

Ming Pei You ◽

Patrick M. Finnegan ◽

Surinder S. Banga ◽

Huang Yi ◽

...

Keyword(s):

Sclerotinia Sclerotiorum ◽

Lesion Size ◽

Resistance Mechanisms ◽

Post Inoculation ◽

Sclerotinia Stem Rot ◽

Raphanus Raphanistrum ◽

Seedling Resistance ◽

First Report ◽

Average Size ◽

Resistant Genotypes

Sclerotinia stem rot, caused by Sclerotinia sclerotiorum, is a serious disease of many cruciferous crops and frequently poses a threat to the sustainable and profitable production of these crops worldwide. Differences in seedling resistance to S. sclerotiorum across 46 diverse cruciferous genotypes from 12 different species were assessed by comparing the extent of pathogenesis on inoculated cotyledons under controlled conditions. Selections of Brassica carinata, B. incana, B. juncea, B. napus, and B. napus introgressed with B. carinata, B. nigra, B. oleracea, B. rapa var. rosularis, B. rapa var. chinensis, B. tournefortii, Raphanus raphanistrum, R. sativus, and Sinapis arvensis were tested. The average size of lesions on cotyledons 48 h post inoculation varied from 0.8 to 7.3 mm. The three most resistant genotypes with the smallest lesions were all from B. oleracea (viz., B. oleracea var. italica ‘Prophet’ and B. oleracea var. capitata ‘Burton’ and ‘Beverly Hills’). Representatives of R. raphanistrum, S. arvensis, B. juncea, and B. carinata were the most susceptible to S. sclerotiorum, with the largest lesions. To our knowledge, this is the first report of high levels of resistance to S. sclerotiorum in B. oleracea at the cotyledon stage and also the first report of the host cotyledon reactions against S. sclerotiorum for all tested species except B. napus and B. juncea. The mean lesion size for B. napus introgressed with B. carinata was 5.6 mm, which is midway between the lesion size for the two parent species B. napus (5.1 mm) and B. carinata (5.8 mm). Separate genetic control for cotyledon versus mature plant resistance was demonstrated by the lack of correlation between lesion size from S. sclerotiorum on the cotyledon with the severity of disease initiated by stem inoculation or natural processes in a previous field test. On the most resistant genotypes, B. oleracea var. italica Prophet and var. capitata Burton, growth of S. sclerotiorum on the cotyledon surface prior to penetration was severely impeded, production of appressoria inhibited, and both cytoplasm shrinkage and protoplast extrusion in S. sclerotiorum hyphae prevalent. This is the first report of such resistant mechanisms in B. oleracea. Genotypes with cotyledon resistance identified in this study will be of great value not only in furthering our understanding of resistance mechanisms across different cruciferous species but also could be exploited for developing commercial crucifer cultivars with high-level resistance against S. sclerotiorum.

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Determination of chemical component of essential oil of Origanum dubium plants grown at different altitudes and antifungal activity against Sclerotinia sclerotiorum

Journal of Food Processing and Preservation ◽

10.1111/jfpp.15787 ◽

2021 ◽

Author(s):

Musa Türkmen ◽

Merve Kara ◽

Hasan Maral ◽

Soner Soylu

Keyword(s):

Antifungal Activity ◽

Essential Oil ◽

Sclerotinia Sclerotiorum ◽

Chemical Component ◽

Different Altitudes

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Impact of time between field application of Bacillus subtilis strains SB01 and SB24 and inoculation with Sclerotinia sclerotiorum on the suppression of Sclerotinia stem rot in soybean

European Journal of Plant Pathology ◽

10.1007/s10658-011-9790-6 ◽

2011 ◽

Vol 131 (1) ◽

pp. 95-102 ◽

Cited By ~ 4

Author(s):

Jinxiu Zhang ◽

Allen G. Xue ◽

Malcolm J. Morrison ◽

Yao Meng

Keyword(s):

Bacillus Subtilis ◽

Sclerotinia Sclerotiorum ◽

Field Application ◽

Stem Rot ◽

Sclerotinia Stem Rot

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Prevalence of sclerotinia stem rot of canola in New South Wales

Australian Journal of Experimental Agriculture ◽

10.1071/ea02027 ◽

2003 ◽

Vol 43 (2) ◽

pp. 163 ◽

Cited By ~ 18

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.

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