Evaluation of Inoculation Methods to Determine Resistance Reactions of Wheat to Fusarium graminearum

Reliable greenhouse assays are needed to differentiate types of resistance in wheat to Fusarium graminearum. Genotypes with known field reactions were evaluated for resistance type using four greenhouse inoculation techniques. Percentage of spikelets with symptoms per spike (severity) and percentage of inoculated spikelets per spike developing symptoms were assessed 7, 10, and 14 days after inoculation (DAI). Genotypes were evaluated using disease assessments 14 DAI and area under the disease progress curve (AUDPC). Significant genotype-inoculation technique interactions for disease assessments indicated that genotypes responded differently to greenhouse inoculation techniques. The central floret injection technique used to assess resistance to spread within the spike (type II resistance) did not indicate a resistant response in genotypes with low field disease severity (putative type II). Atomizing macroconidia onto spikes, used to assess resistance to primary infection (type I resistance), indicated a resistant response in one of five genotypes with low field disease incidence (percentage of spikes with symptomatic spikelets) (putative type I). The inoculation techniques in the greenhouse were unable to differentiate between different types of partial resistance. Results indicated disparity in the ability of greenhouse inoculation methods to identify genotypes with partial resistance as observed in the field. It was concluded that atomizing conidia onto the spikes and assessing disease severity did not differentiate between resistance types. Additionally, a one-time assessment 14 DAI was determined to be as informative as multiple assessments and calculating the AUDPC.

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Mapping the A Genome for QTL Conditioning Resistance to Fusarium Head Blight in a Wheat Population with Triticum timopheevii Background

Plant Disease ◽

10.1094/pdis-02-16-0144-re ◽

2017 ◽

Vol 101 (1) ◽

pp. 11-19 ◽

Cited By ~ 2

Author(s):

Ali Malihipour ◽

Jeannie Gilbert ◽

George Fedak ◽

Anita Brûlé-Babel ◽

Wenguang Cao

Keyword(s):

Disease Severity ◽

Phenotypic Variation ◽

Disease Incidence ◽

Field Conditions ◽

Type I ◽

Type Ii ◽

Triticum Timopheevii ◽

Marker Interval ◽

Head Blight ◽

Fhb Resistance

Development and use of resistant wheat cultivars is the most practical and economical approach for the control of Fusarium head blight (FHB). In the present study, a population of recombinant inbred lines derived from the cross between ‘AC Brio’ (a Canadian bread wheat cultivar moderately susceptible to FHB) and ‘TC 67’ (an FHB-resistant cultivar derived from Triticum timopheevii) was used to map quantitative trait loci (QTL) for FHB resistance using microsatellite molecular markers. Multiple interval mapping detected several QTL for FHB resistance on the chromosomes 5AL and 6A. The QTL detected in the marker interval of cfd6.1-barc48 on chromosome 5AL explained 10.9, 5.2, and 7.8% of phenotypic variation for disease incidence (type I resistance), disease severity (a combination of type I and type II resistance), and Fusarium-damaged kernels (FDK) (type IV resistance) under field conditions, respectively. The second QTL mapped to 5AL, in the marker interval of cfd39-cfa2185, explained 19.4 and 20.6% of phenotypic variation for FDK under field conditions and disease severity in the greenhouse (type II resistance), respectively. The QTL located on chromosome 6A conferred resistance to disease incidence and severity under field conditions and to disease severity in the greenhouse, explaining 6.8 to 11.8% of phenotypic variation for these traits. Several QTL for agronomic traits were also mapped in this study, including one and two QTL to the chromosomes 2A and 5AL, respectively, all for plant height, and two QTL to chromosome 6A for plant height and flowering date, respectively. The 5AL QTL for FHB resistance mapped in the marker interval of cfd39-cfa2185 in the present study is a novel QTL that originated from T. timopheevii and is reported here for the first time. Further validation of this QTL is required for wheat breeding programs to enhance resistance levels to FHB.

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Cotton resistance to ramulose and variability of Colletotrichum gossypii f. sp. cephalosporioides

Summa Phytopathologica ◽

10.1590/s0100-54052006000100001 ◽

2006 ◽

Vol 32 (1) ◽

pp. 9-15 ◽

Cited By ~ 4

Author(s):

Jefferson Fernandes do Nascimento ◽

Laércio Zambolim ◽

Francisco Xavier Ribeiro do Vale ◽

Paulo Geraldo Berger ◽

Paulo Roberto Cecon

Keyword(s):

Disease Severity ◽

Disease Incidence ◽

Disease Index ◽

Mato Grosso ◽

Progress Curve ◽

Commercial Cultivars ◽

Resistant Group ◽

The Relationship ◽

Highly Virulent ◽

Susceptible Group

Four cultivars and 21 lines of cotton were evaluated for resistance to ramulose (Colletotrichum gossypii f. sp. cephalosporioides) in a field where the disease is endemic. The seeds of each genotype were planted in 5 x 5 m plots with three replications. The lines CNPA 94-101 and 'CNPA Precoce 2'were used as standard susceptible and resistant references, respectively. The disease incidence (DI) was calculated from the proportion of diseased plants in the plot. The disease index (DIn) was calculated from the disease severity using a 1 to 9 scale, and was evaluated at weekly intervals starting 107 days after emergence. The data collected was used to calculate the area under disease progress curve (AUDPC). In general, the DIn increased linearly with time and varied from 20.0 to 57.1 and AUDPC from 567 to 1627 among the genotypes which could be clustered in to two distinct groups. The susceptible group contained two cultivars and nine lines and the resistant group contained one cultivar and 12 lines. The relationship between disease index and evaluation times was linear for the 25 genotypes tested. The line CNPA 94-101, used as susceptible standard, was the most susceptible with an average DI = 83.4, DIn = 57.1 and AUDPC = 1627.7. The line CNPA 96-08 with DI = 37.8, DIn = 20.0 and AUDPC = 567.7 was the most resistant one. Among the commercial cultivars 'IAC 22' was the most susceptible and 'CNPA Precoce 2', used as resistant standard was the most resistant. The variability in virulence of the pathogen was studied by spray inoculating nine genotypes with conidial suspensions (10(5)/mL) of either of the 10 isolates. The disease severity was evaluated 30 days later using a scale of 1 to 5. The virulence of the isolate was expressed by DIn. All the isolates were highly virulent but their virulence avaried for several genotypes and could be clustered in two distinct groups of less and more virulent isolates. The isolate MTRM 14 from Mato Grosso was the least virulent while Minas Gerais was the most virulent, with DIn of 6.36 and 46.47, respectively. In this experiment the line HR 102 and the cultivar 'Antares' were the most resistant ones with DIns of 18.32 and 19.14, respectively.

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The Pressure of Fusarium Disease and Its Relation with Mycotoxins in The Wheat Grain and Malt

Toxins ◽

10.3390/toxins11040198 ◽

2019 ◽

Vol 11 (4) ◽

pp. 198 ◽

Cited By ~ 6

Author(s):

Valentina Spanic ◽

Zvonimir Zdunic ◽

Georg Drezner ◽

Bojan Sarkanj

Keyword(s):

De Novo ◽

Disease Incidence ◽

Type I ◽

Head Blight ◽

Wheat Varieties ◽

Progress Curve ◽

Resistant Varieties ◽

Type I Resistance ◽

One Year ◽

Moderately Resistant

Fusarium head blight (FHB) is one of the most destructive wheat fungal diseases, causing yield loss, quality reduction, and accumulation of mycotoxins. The aim of this research was to summarize the occurrence of major Fusarium mycotoxins: deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-AcDON), nivalenol (NIV), and zearalenone (ZEN) in two consecutive years to search the relationship between disease incidence and severity with mycotoxins found in control and inoculated grains and corresponding malt. In addition, deoxynivalenol-3-glucoside (D3G) in one-year research was measured. Tested wheat varieties showed infection scores of 3% (‘U1’ and ‘Sirban Prolifik’) to 79% (‘Golubica’) for Type I resistance evaluation. There were few moderately resistant varieties in view of their areas under the disease progress curve, which can be considered Type III resistance (‘Sirban Prolifik’ and ‘U1’). According to the data quantified by LC–MS/MS, DON decreased in infected malt in comparison to corresponding grain, while ZEN occurred only in infected malt samples. Both 3-AcDON and NIV increased in inoculated malt in comparison to corresponding grain, due to a combination of plant metabolism and de novo synthesis by molds during malting. Based on the results, we can draw a few conclusions: the resistance to Fusarium decreased quantified concentrations of DON; ZEN gets synthetized during malting; unregulated 3-AcDON and NIV increase during malting; more resistant varieties have converted DON to D3G more successfully. Modified mycotoxins should be also included to legislation, since they could be transformed back to the corresponding mycotoxins under food processing conditions or during digestion.

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Genetic analysis of Okra Yellow Vein Mosaic Virus disease resistance in wild relative of okra Abelmoschus angulosus Wall. ex Wight & Arn

Plant Genetic Resources ◽

10.1017/s1479262119000078 ◽

2019 ◽

Vol 17 (04) ◽

pp. 346-351

Author(s):

SamanthiKumari Wasala ◽

Sumudu I. Senevirathne ◽

Jayantha Bandara Senanayake ◽

Anuradini Navoditha

Keyword(s):

Disease Resistance ◽

Mosaic Virus ◽

Disease Severity ◽

Virus Disease ◽

Disease Incidence ◽

Severity Index ◽

Yellow Vein ◽

Wild Relative ◽

Yellow Vein Mosaic Virus ◽

Progress Curve

AbstractWild relative of okra, Abelmoschus angulosus Wall. ex Wight & Arn. was identified as a resistant germplasm for Okra Yellow Vein Mosaic Virus (OYVMV) which is the devastating disease for okra cultivation in Sri Lanka. The mode of resistance of OYVMV in A. angulosus was studied with the aim of tagging responsible genes for the disease resistance. Wide hybridization was performed between A. angulosus and highly virus susceptible A. esculentus variety, MI-7. Very poor seed setting was observed in F1 and F2 generations due to post zygotic abortion. Disease screening was carried out using F1 and F2:3 populations along with parents in the field under induced disease pressure. Disease severity index and area under disease progress curve were calculated to measure disease severity. Number of genes segregating for OYVMV disease resistance was calculated for the F2:3 generation. Modified Wright's formula was used to estimate the effective gene number and mode of inheritance by a quantitative method. A χ2 test was performed for qualitative analysis. Plants of A. angulosus were totally free of virus incidence while 100% disease incidence was observed in the variety MI-7. F2:3 population showed between and within progeny segregation for disease incidence. Results indicated that the disease susceptibility was dominant over resistance. χ2 analysis revealed that the segregation of disease severity was significantly fit to the gene model of 9:6:1 (χ2 = 0.1757 at P ≤ 0.05) suggesting the disease resistance in A. angulosus is governing by two recessive genes in an additive manner. Result was confirmed by the quantitative analysis.

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A comparison of field inoculation methods with Cercosporella herpotrichoides (Fron) on spring barley

The Journal of Agricultural Science ◽

10.1017/s0021859600020050 ◽

1969 ◽

Vol 73 (3) ◽

pp. 437-444 ◽

Cited By ~ 4

Author(s):

D. Gareth Jones ◽

J. M. L. Davies

Keyword(s):

Grain Yield ◽

Disease Severity ◽

Disease Incidence ◽

Spring Barley ◽

Barley Variety ◽

Field Inoculation ◽

Inoculation Methods ◽

Field Plots

SUMMARYA comparison was made of six different methods of inoculation with Cercosporella herpotrichoidesFron on field plots of the spring barley variety Impala. All inoculation treatments produced significant differences in terms of disease incidence and grain yield compared with the uninoculated controls. Significant differences were found between treatments in terms of disease incidence, disease severity, mean yield/head and 1000 grain weights. The time of inoculation was also found to be significant. The earlier inoculation caused a reduction in yield of approximately 66 % compared with 50 % at the later inoculation. The application of these methods is discussed.

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Determination of the most susceptible phenological stage of rice panicles to infection by species of Fusarium graminearum

Summa Phytopathologica ◽

10.1590/0100-5405/192513 ◽

2019 ◽

Vol 45 (3) ◽

pp. 243-246

Author(s):

Bruno Tabarelli Scheidt ◽

Ricardo Trezzi Casa ◽

Otávio Ajala Fiorentin ◽

Flávio Chupel Martins ◽

Paulo Kuhnem ◽

...

Keyword(s):

Disease Severity ◽

Fusarium Graminearum ◽

Species Complex ◽

Phenological Stage ◽

Flowering Stage ◽

Phenological Stages ◽

Progress Curve ◽

Rice Hybrid ◽

Rice Panicles

ABSTRACT Occurrence of rice seeds infected by Fusarium graminearum has shown the importance of identifying the most favorable phenological stage of panicles to grain infection. The experiments were conducted in two crop seasons under greenhouse conditions, using the rice hybrid INOV CL. The phenological stages during inoculation were complete booting, full heading and flowering. All plots were inoculated using two isolates of Fusarium graminearium species complex 15A (F. graminearium - 15-ADON) and FmNiv (F. meridionale - Nivalenol). Disease severity was estimated at weekly intervals and was used to calculate the area under the disease progress curve (AUDPC), while panicles were collected to determine the percentage of spotted grains and Fusarium incidence. Percentage of spotted grains and incidence of F. graminearum and F. meridionale were greater when inoculation was made during flowering stage, significantly differing from heading and booting stages. Rice flowering stage is more susceptible to infection by F. graminearum and F. meridionale, inducing higher disease severity and incidence of spotted grains, as well as presence of fungi in the grains. Flowering was the most susceptible stage in the two crop seasons for both isolates, and the complete booting stage presented the lowest values of AUDPC.

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Evaluation of Inoculation Methods to Reproduce Sunflower Premature Ripening Caused by Phoma macdonaldii

Plant Disease ◽

10.1094/pdis-03-10-0180 ◽

2010 ◽

Vol 94 (12) ◽

pp. 1398-1404 ◽

Cited By ~ 10

Author(s):

C. Seassau ◽

P. Debaeke ◽

E. Mestries ◽

G. Dechamp-Guillaume

Keyword(s):

Helianthus Annuus ◽

Disease Severity ◽

Root Systems ◽

Spore Suspension ◽

Stem Base ◽

Inoculation Methods ◽

Progress Curve ◽

Root Necrosis ◽

Phoma Macdonaldii

Three inoculation methods were evaluated for effectiveness to cause sunflower premature ripening (PR). Evaluations were conducted on a sunflower (Helianthus annuus) cultivar susceptible to PR in replicated, multilocation experiments under greenhouse conditions. Plants were inoculated with Phoma macdonaldii, either with mycelium, conidia, or infected residues at the stem base or with buried residues. Disease severity (DS) was measured by percent girdling necrosis at the stem base and percent final PR; the infection spread was assessed using the area under the disease progress curve (AUDPC). Inoculation with mycelia or 1 × 106 spores/ml caused significantly more DS and PR than lower spore concentrations or infected residues (P < 0.05). Amending soil with residues induced root necrosis but no PR. P. macdonaldii was mainly isolated at the stem base and above but rarely on root systems. Microscopic evaluations showed that hyphae colonized mainly the cortex and vascular stem tissues. The overall results demonstrated a clear role of aerial infection in PR compared with soilborne inoculum, and that inoculation at the stem base with a spore suspension could be used for screening genotypes for resistance to PR.

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Post-Anthesis Moisture Increased Fusarium Head Blight and Deoxynivalenol Levels in North Carolina Winter Wheat

Phytopathology ◽

10.1094/phyto-99-4-0320 ◽

2009 ◽

Vol 99 (4) ◽

pp. 320-327 ◽

Cited By ~ 78

Author(s):

Christina Cowger ◽

Jennifer Patton-Özkurt ◽

Gina Brown-Guedira ◽

Leandro Perugini

Keyword(s):

Fusarium Head Blight ◽

Disease Severity ◽

Disease Incidence ◽

Weather Conditions ◽

Selective Medium ◽

First Year ◽

Type I ◽

Head Blight ◽

Fourfold Increase ◽

Screening Programs

Current models for forecasting Fusarium head blight (FHB) and deoxynivalenol (DON) levels in wheat are based on weather near anthesis, and breeding for resistance to FHB pathogens often relies on irrigation before and shortly after anthesis to encourage disease development. The effects of post-anthesis environmental conditions on FHB are poorly understood. We performed a field experiment at Kinston, NC, to explore the effects of increasing duration of post-anthesis moisture on disease incidence, disease severity, Fusarium-damaged kernels (FDK), percent infected kernels, and DON. The experiment had a split-plot design, and one trial was conducted in each of two successive years. Main plots consisted of post-anthesis mist durations of 0, 10, 20, or 30 days. Subplots were of eight cultivars in the first year and seven in the second year, two being susceptible to FHB and the remainder each with varying degrees of apparent type I and type II resistance. Plots were inoculated by spraying Fusarium graminearum macroconidia at mid-anthesis. Averaging across years and cultivars, 10 or 20 days of post-anthesis mist had the same effect (P ≥ 0.198) and were associated with an approximately fourfold increase in mean disease incidence and eightfold increase in disease severity compared with 0 days of mist (P ≤ 0.0002). In both years, mean FDK percentages at 0 and 10 days post-anthesis mist were the same and significantly lower than FDK percentages under 20 or 30 days of post-anthesis mist. Mist duration had a significant effect on percent kernels infected with Fusarium spp. as detected by a selective medium assay of 2007 samples. Averaging across all cultivars, in both years, DON levels increased significantly for 10 days compared with 0 days of mist, and increased again with 20 days of mist (P ≤ 0.04). This is the first investigation to show that extended post-flowering moisture can have a significant enhancing effect on FHB, FDK, DON, and percent infected kernels of wheat. For all disease and toxin assays, cultivar rankings were significantly noncorrelated among mist durations in at least 1 year, suggesting that FHB screening programs might rank genotypes differently under extended post-anthesis moisture than without it. Our findings also imply that accurate forecasts of DON in small grains must take account of post-anthesis weather conditions.

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Mapping Resistance to Argentinean Fusarium (Graminearum) Head Blight Isolates in Wheat

International Journal of Molecular Sciences ◽

10.3390/ijms222413653 ◽

2021 ◽

Vol 22 (24) ◽

pp. 13653

Author(s):

Carolina Sgarbi ◽

Ismael Malbrán ◽

Luciana Saldúa ◽

Gladys Albina Lori ◽

Ulrike Lohwasser ◽

...

Keyword(s):

Fusarium Graminearum ◽

Wheat Yield ◽

Kernel Weight ◽

Type I ◽

Type Ii ◽

Head Blight ◽

Yield And Quality ◽

Type I Resistance ◽

Additive Qtls ◽

Type Ii Resistance

Fusarium head blight (FHB) of wheat, caused by Fusarium graminearum (Schwabe), is a destructive disease worldwide, reducing wheat yield and quality. To accelerate the improvement of scab tolerance in wheat, we assessed the International Triticeae Mapping Initiative mapping population (ITMI/MP) for Type I and II resistance against a wide population of Argentinean isolates of F. graminearum. We discovered a total of 27 additive QTLs on ten different (2A, 2D, 3B, 3D, 4B, 4D, 5A, 5B, 5D and 6D) wheat chromosomes for Type I and Type II resistances explaining a maximum of 15.99% variation. Another four and two QTLs for thousand kernel weight in control and for Type II resistance, respectively, involved five different chromosomes (1B, 2D, 6A, 6D and 7D). Furthermore, three, three and five QTLs for kernel weight per spike in control, for Type I resistance and for Type II resistance, correspondingly, involved ten chromosomes (2A, 2D, 3B, 4A, 5A, 5B, 6B, 7A, 7B, 7D). We were also able to detect five and two epistasis pairs of QTLs for Type I and Type II resistance, respectively, in addition to additive QTLs that evidenced that FHB resistance in wheat is controlled by a complex network of additive and epistasis QTLs.

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Application of chemical compounds during pre-harvesting to control post-harvesting green mold in citrus

Semina Ciências Agrárias ◽

10.5433/1679-0359.2021v42n4p2135 ◽

2021 ◽

Vol 42 (4) ◽

pp. 2135-2150

Author(s):

Marines Batalha Moreno Kirinus ◽

◽

Keilor da Rosa Dorneles ◽

Pricila Santos Silva ◽

Caroline Farias Barreto ◽

...

Keyword(s):

Disease Severity ◽

Sodium Selenite ◽

Disease Incidence ◽

Acquired Resistance ◽

Equatorial Region ◽

Potassium Silicate ◽

Expansion Rate ◽

Green Mold ◽

Progress Curve ◽

Post Harvesting

This study aimed to evaluate the effect of system-acquired resistance inducing compounds applied during the pre-harvest of ‘Navelina’ orange and ‘Ortanique’ tangor in controlling post-harvest disease caused by Penicillium digitatum. The products applied were acibenzolar-s-methyl (ASM), imidacloprid (IMI), methyl jasmonate (MeJa), sodium selenite, potassium silicate, and thiamethoxam (TMT). Sterile distilled water was used as the control. The applications were administered 45, 30, and 15 days before harvesting. In 2015 and 2016, 840 fruits were randomly collected, and when they reached commercial maturation, they were sanitized, half were pierced with a needle in the equatorial region. The fruits were inoculated with a 10 μL spore suspension (1 × 106 conidia mL-1) of P. digitatum, in the equatorial region. The experiment was performed with three replicates, each comprising 10 fruits and repeated over two consecutive crop seasons. Disease incidence was evaluated on pierced (at 72 and 144 h after inoculation [hai]) and unperforated (at 360 hai) fruits. For pierced fruits, lesion expansion rate (rL), disease severity, expansion rate of sporulating area (rE), and sporulating area were evaluated. The area under the disease progress curve (AUDPC) and the area under the sporulating area progress curve were calculated. Both cultivars were susceptible; however, the rL and rE had lower values for ‘Ortanique’. The tested products reduced the disease incidence in both cultivars. Potassium silicate reduced rL and rE, whereas sodium selenite reduced rE. The disease severity was reduced by potassium silicate, sodium selenite, and ASM. AUDPC was reduced by sodium selenite and potassium silicate treatments. Among the tested products, potassium silicate and sodium selenite applied during the pre-harvest of ‘Navelina’ orange and ‘Ortanique’ tangor had the highest reductions for disease incidence (ranging from 14% to 37%, respectively) and severity (60% and 70%, respectively), rE (50% for both compounds), and total sporulating area (55% and 56%, respectively), reducing the green mold in postharvested fruits caused by P. digitatum.

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