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Richard W. Smiley - One of the best experts on this subject based on the ideXlab platform.

  • Fusarium Crown Rot of Winter Wheat Influenced by Resource Competition Near a Tree Windbreak.
    Plant disease, 2019
    Co-Authors: Richard W. Smiley, Stephen Machado
    Abstract:

    Fusarium Crown Rot becomes most severe when wheat is stressed for water near the time of anthesis. This research examined the potential to study Crown Rot in the gradient of resource competition near a tree windbreak. Winter wheat was planted for 2 years into a field infested by Fusarium pseudograminearum and bordered by 17-m-high Austrian pines. Crown Rot, plant growth and yield, and soil water content were evaluated at six distances (5 to 46 m) perpendicular to the tree line in strip plots inoculated or not inoculated with the pathogen. Crown Rot was minor (

  • Mechanized Method to Inoculate Field Soil to Evaluate Fusarium Crown Rot of Wheat.
    Plant disease, 2019
    Co-Authors: Richard W. Smiley
    Abstract:

    Assessments of Fusarium Crown Rot are often made in field trials inoculated with Fusarium pseudograminearum or F. culmorum. Factors affecting the efficiency of two inoculation procedures were evaluated. Pulverized Fusarium-colonized wheat plus oat grain inoculum mixed with the wheat seed caused more seedling damping-off compared with equal rates of colonized whole millet seeds placed 2 cm above the wheat seed. Both inoculation systems increased the incidence and severity of Crown Rot. The efficiency of F. pseudograminearum-colonized millet seed inoculum was not reduced when wheat seed was treated with difenoconazole. Crown Rot in inoculated plots became greater when starter fertilizer was applied with or below the wheat seed and when soil below the wheat seed was disrupted by a seed drill with an opener that creates a groove or trench directly below the seed. No biologically important associations were detected between whiteheads and other measures of Crown Rot, grain yield, or grain test weight. The millet seed inoculation system was the most efficient for wheat production systems in the semiarid U.S. Pacific Northwest.

  • Variability of Fusarium Crown Rot Tolerances Among Cultivars of Spring and Winter Wheat
    Plant disease, 2009
    Co-Authors: Richard W. Smiley, Hui Yan
    Abstract:

    Smiley, R. W., and Yan, H. 2009. Variability of Fusarium Crown Rot tolerances among cultivars of spring and winter wheat. Plant Dis. 93:954-961. Crown Rot caused by Fusarium pseudograminearum reduces the yield of wheat (Triticum aestivum) in Oregon. Observations of Crown Rot symptoms in traditional breeding and yield testing nurseries have not been useful for describing tolerance ratings of wheat cultivars. Yield data from inoculated experiments were therefore evaluated to determine if differences in cultivar response could be identified. A comparison of yields in inoculated and noninoculated plots was made for one group of spring wheat entries and four groups of winter wheat entries. Significant differences among spring wheat entries were identified and were validated against standards for tolerance and intolerance to F. pseudograminearum in Australia. Locally adapted and Australian standards exhibited a comparable range of yield reduction due to inoculation. Spring wheat tolerance reactions can be accurately described using as few as 24 yield comparisons. However, this screening method will not be practical for winter wheat due to stronger effects of year and location on the phenotypic tolerance response, requiring about 95 yield comparisons to accurately define the Crown Rot phenotype of a winter wheat cultivar.

  • Crop Damage Estimates for Crown Rot of Wheat and Barley in the Pacific Northwest.
    Plant disease, 2005
    Co-Authors: Richard W. Smiley, Jennifer A. Gourlie, Sandra A. Easley, Lisa-marie Patterson, Ruth G. Whittaker
    Abstract:

    ABSTRACT Crown Rot of wheat and barley in the Pacific Northwest is caused by a complex of Fusarium pseudograminearum, F. culmorum, F. avenaceum, Bipolaris sorokiniana, and Microdochium nivale. Yield-loss estimates were made by evaluating yield components on tillers collected from commercial fields and sorted by disease severity classes, and by comparing yields for field plots inoculated with F. pseudograminearum with yields in naturally infested soil. Increasing Crown Rot severity caused an increase in grain pRotein content and reduction in grain yield, kernels per head, kernel weight, test weight, tiller height, and straw weight. Crown Rot reduced winter wheat yield as much as 1,550 kg/ha (35%, $219/ha) in commercial fields, with a 13-field mean of 9.5% ($51/ha). Inoculation reduced yields as much as 2,630 kg/ha (61%, $372/ha) over that caused by the native pathogen flora. Rain-induced crusting of the soil surface greatly amplified preemergence damping-off caused by F. pseudograminearum. Crown Rot caused...

Daniel Hüberli - One of the best experts on this subject based on the ideXlab platform.

Mark W. Sutherland - One of the best experts on this subject based on the ideXlab platform.

  • The Crown Rot ‘deadhead’ phenomenon in durum wheat
    2015
    Co-Authors: Noel L. Knight, Mark W. Sutherland
    Abstract:

    [INTRODUCTION] Crown Rot of wheat, caused by Fusarium pseudograminearum (Fp), is a serious disease threat across the Australian wheat belt, particularly in durum wheat. Control of this disease is primarily based on crop Rotations and reducing inoculum, with a continued goal of producing crops with increased resistance. Plant reactions to disease are typically described using stem browning, sometimes coinciding with the production of ‘deadheads’, or stems undergoing premature senescence due to infection. The mechanism by which Crown Rot causes yield loss has not yet been clearly described, however evidence is emerging indicating fungal blockage of both xylem and phloem tissues (1). It would be logical to infer that ‘deadhead’ stems had more Fp biomass and greater vascular tissue colonisation, resulting in their premature death. It must, however, be demonstrated. The information gained by examining ‘deadheads’ may be applied to less extreme infections as an explanation for the physiological effects behind Crown Rot associated yield loss. The idea behind this experiment was to investigate the levels of colonisation of stems of durum plants exhibiting ‘deadheads’ in the field and compare these to stems of the same plants which were still living. Microscopic assessment of stem sections is also planned.

  • Fusarium pseudograminearum Crown Rot: growth patterns in planta
    2014
    Co-Authors: Noel L. Knight, Mark W. Sutherland
    Abstract:

    Crown Rot (causal agent Fusarium pseudograminearum) is a major constraint on wheat production in Australia and globally. While discolouration of tissues is commonly used to screen for resistance, the degree to which the pathogen colonises the full range of seedling and adult host tissues is an important aspect of the disease process. After coleoptile inoculation, seedlings were examined using quantitative PCR to determine the spread of F. pseudograminearum into different host tissues during Crown Rot pathogenesis at 14 and 28 days after inoculation. Quantitative PCR and visual assessment indicated that while most seedling tissues (leaf sheath, leaf blade, sub-Crown internode, primary root and secondary root) were colonised, the basal portion of leaf sheath tissue supported the highest density of F. pseudograminearum. Microscopic assessment demonstrated the growth of hyphae predominantly in the parenchyma cells, with passage into and out of seedling shoot tissues being predominantly via stomata. Assessment of colonised stem tissues in inoculated field trials of adult plants at 16 and 22 weeks after planting indicate a strong correlation between visual discolouration and fungal biomass, with the discolouration occurring in the parenchymatous hypoderm. Hyphae spread from the culm base vertically through the tissues, initially via the hypoderm and the central pith cavity. Colonisation of sclerified cells occurs later in the disease process. Both xylem and phloem tissues became colonised by 16 weeks after planting in all host genotypes tested. Nodal tissues do not appear to constitute any major impediment to the spread of fungal infection. The observation of F. pseudograminearum colonisation of vascular tissues is consistent with the hypothesis of compromised vascular flow of either or both of the xylem and phloem pathways during Crown Rot disease.

  • Introgression of hexaploid sources of Crown Rot resistance into durum wheat
    Euphytica, 2013
    Co-Authors: Anke Martin, S. Simpfendorfer, Ray A. Hare, Mark W. Sutherland
    Abstract:

    Triticum turgidum ssp. durum (tetraploid durum) germplasm is very susceptible to Crown Rot, caused by the fungus Fusarium pseudograminearum. Screening activities to date have failed to identify even moderately susceptible lines. In contrast partial resistance to this disease has been identified in a number of Triticum aestivum (hexaploid wheat) lines, including 2-49 and Sunco. This study describes the successful introgression of partial Crown Rot resistance from each of these two hexaploid wheat lines into a durum wheat background. Durum backcross populations were produced from two 2-49/durum F6 lines which did not contain any D-genome chromosomes and which had Crown Rot scores similar to 2-49. F2 progeny of these backcross populations included lines with field based resistance to Crown Rot superior to that of the parent hexaploid wheat.

  • pyramiding qtl increases seedling resistance to Crown Rot fusarium pseudograminearum of wheat triticum aestivum
    Theoretical and Applied Genetics, 2010
    Co-Authors: G.b. Wildermuth, William D. Bovill, D. J. Herde, M. Davis, M Horne, Mark W. Sutherland
    Abstract:

    Crown Rot of wheat (Triticum aestivum), predominantly caused by the fungus Fusarium pseudograminearum, has become an increasingly important disease constraint in many winter cereal production regions in Australia. Our group has previously identified a range of quantitative trait loci (QTL) for partial resistance to Crown Rot in various bread wheat sources. Here, we report on work that has assessed the effectiveness of pyramiding QTL to improve resistance to Crown Rot. Two doubled haploid populations were analysed—one from a cross between two previously characterised sources of partial seedling resistance (2-49 and W21MMT70; n = 208) and one from a cross between 2-49 and the commercial variety Sunco, a source of adult field resistance (n = 134). Both populations were phenotyped for seedling resistance to Crown Rot. Microsatellite and DArT markers were used to construct whole genome linkage maps for use in composite interval mapping (CIM) to identify QTL. Three QTL were detected in both trials conducted on the 2-49/W21MMT70 population. These were located on chromosomes 1D (QCr.usq-1D.1), 3B (QCr.usq-3B.1) and 7A. QCr.usq-1D.1 and the previously undetected 7A QTL were inherited from 2-49. QCr.usq-3B.1, inherited from W21MMT70, was the most significant of the QTL, explaining up to 40.5% of the phenotypic variance. Three QTL were identified in multiple trials of the Sunco/2-49 population. These were located on chromosomes 1D (QCr.usq-1D.1), 2B (QCr.usq-2B.2) and 4B (QCr.usq-4B.1). Only QCr.usq-2B.2 was inherited from Sunco. QCr.usq-4B.1 was the most significant of these QTL, explaining up to 19.1% of the phenotypic variance. In the 2-49/W21MMT70 population, several DH lines performed significantly better than either parent, with the best recording an average disease severity rating of only 3.8% of that scored by the susceptible check cultivar Puseas. These lines represent a new level of seedling Crown Rot resistance in wheat.

  • Crown Rot of winter cereals: integrating molecular studies and germplasm improvement
    2009
    Co-Authors: Mark W. Sutherland, William D. Bovill, F. Eberhard, A. Lehmensiek, D. J. Herde, S. Simpfendorfer
    Abstract:

    Crown Rot of winter cereals is a major constraint on grain production across most growing regions in Australia, particularly where stubble retention is practiced to maintain soil structure and retain soil water. The predominant cause of this disease is infection with Fusarium pseudograminearum (Fpg), although in some southern areas Fusarium culmorum infections are also significant. These Fusarium species are able to grow saprophytically on stubble remnants over the summer and provide inoculum for crop infection in the following season. Losses due to Crown Rot are highest in seasons featuring a dry finish in which maturing plants experience water stress, with symptoms including basal stem browning and white heads bearing no grain.

L. De Lapeyre De Bellaire - One of the best experts on this subject based on the ideXlab platform.

  • The susceptibility of bananas to Crown Rot disease is influenced by geographical and seasonal effects
    Canadian Journal of Plant Pathology, 2013
    Co-Authors: Cécile Annie Ewané, Ludivine Lassois, Yves Brostaux, Philippe Lepoivre, L. De Lapeyre De Bellaire
    Abstract:

    Abstract Crown Rot of banana fruits is caused by a complex of fungal pathogens, the most common of which is Colletotrichum musae, and is one of the main quality defects of exported bananas. Susceptibility of banana fruits to Crown Rot is influenced by many pre-harvest factors. The aim of this study was to improve on the methodology for the evaluation of fruit susceptibility and to verify whether cultivation areas in Cameroon as well as seasonal variations have an influence on the susceptibility to Crown Rot. Fruit susceptibility was evaluated on a monthly basis throughout a year (including the dry and rainy seasons) in three banana plantations located in very different agro-ecological conditions (two in a lowland area and one in a highland area). Fruit susceptibility was determined through an internal necRotic surface (INS) assessment after artificial inoculation with C. musae. The standardization of post-inoculation environmental conditions enabled more reliable INS assessments. Fruit susceptibility was ...

  • Hand position on the bunch and source-sink ratio influence the banana fruit susceptibility to Crown Rot disease.
    Annals of Applied Biology, 2010
    Co-Authors: Ludivine Lassois, Héloïse Bastiaanse, Marc Chillet, Alexandra Jullien, Mohamed Jijakli, L. De Lapeyre De Bellaire
    Abstract:

    The postharvest development of Crown Rot of bananas depends notably on the fruit susceptibility to this disease at harvest. It has been shown that fruit susceptibility to Crown Rot is variable and it was suggested that this depends on environmental preharvest factors. However, little is known about the preharvest factors influencing this susceptibility. The aim of this work was to evaluate the extent to which fruit filling characteristics during growth and the fruit development stage influence the banana susceptibility to Crown Rot. This involved evaluating the influence of (a) the fruit position at different levels of the banana bunch (hands) and (b) changing the source-sink ratio (So-Si ratio), on the fruit susceptibility to Crown Rot. The fruit susceptibility was determined by measuring the internal necRotic surface (INS) after artificial inoculation of Colletotrichum musae. A linear correlation (r = ?0.95) was found between the hand position on the bunch and the INS. The So-Si ratio was found to influence the pomological characteristics of the fruits and their susceptibility to Crown Rot. Fruits of bunches from which six hands were removed (two hands remaining on the bunch) proved to be significantly less susceptible to Crown Rot (INS = 138.3 mm2) than those from bunches with eight hands (INS = 237.9 mm2). The banana susceptibility to Crown Rot is thus likely to be influenced by the fruit development stage and filling characteristics. The present results highlight the importance of standardising hand sampling on a bunch when testing fruit susceptibility to Crown Rot. They also show that hand removal in the field has advantages in the context of integrated pest management, making it possible to reduce fruit susceptibility to Crown Rot while increasing fruit size. (Resume d'auteur)

  • Hand position on the bunch and source–sink ratio influence the banana fruit susceptibility to Crown Rot disease
    Annals of Applied Biology, 2010
    Co-Authors: L. Lassois, Héloïse Bastiaanse, Marc Chillet, Alexandra Jullien, Mohamed Jijakli, L. De Lapeyre De Bellaire
    Abstract:

    The postharvest development of Crown Rot of bananas depends notably on the fruit susceptibility to this disease at harvest. It has been shown that fruit susceptibility to Crown Rot is variable and it was suggested that this depends on environmental preharvest factors. However, little is known about the preharvest factors influencing this susceptibility. The aim of this work was to evaluate the extent to which fruit filling characteristics during growth and the fruit development stage influence the banana susceptibility to Crown Rot. This involved evaluating the influence of (a) the fruit position at different levels of the banana bunch (hands) and (b) changing the source–sink ratio (So–Si ratio), on the fruit susceptibility to Crown Rot. The fruit susceptibility was determined by measuring the internal necRotic surface (INS) after artificial inoculation of Colletotrichum musae. A linear correlation (r = -0.95) was found between the hand position on the bunch and the INS. The So–Si ratio was found to influence the pomological characteristics of the fruits and their susceptibility to Crown Rot. Fruits of bunches from which six hands were removed (two hands remaining on the bunch) proved to be significantly less susceptible to Crown Rot (INS = 138.3 mm2) than those from bunches with eight hands (INS = 237.9 mm2). The banana susceptibility to Crown Rot is thus likely to be influenced by the fruit development stage and filling characteristics. The present results highlight the importance of standardising hand sampling on a bunch when testing fruit susceptibility to Crown Rot. They also show that hand removal in the field has advantages in the context of integrated pest management, making it possible to reduce fruit susceptibility to Crown Rot while increasing fruit size.

William D. Bovill - One of the best experts on this subject based on the ideXlab platform.

  • pyramiding qtl increases seedling resistance to Crown Rot fusarium pseudograminearum of wheat triticum aestivum
    Theoretical and Applied Genetics, 2010
    Co-Authors: G.b. Wildermuth, William D. Bovill, D. J. Herde, M. Davis, M Horne, Mark W. Sutherland
    Abstract:

    Crown Rot of wheat (Triticum aestivum), predominantly caused by the fungus Fusarium pseudograminearum, has become an increasingly important disease constraint in many winter cereal production regions in Australia. Our group has previously identified a range of quantitative trait loci (QTL) for partial resistance to Crown Rot in various bread wheat sources. Here, we report on work that has assessed the effectiveness of pyramiding QTL to improve resistance to Crown Rot. Two doubled haploid populations were analysed—one from a cross between two previously characterised sources of partial seedling resistance (2-49 and W21MMT70; n = 208) and one from a cross between 2-49 and the commercial variety Sunco, a source of adult field resistance (n = 134). Both populations were phenotyped for seedling resistance to Crown Rot. Microsatellite and DArT markers were used to construct whole genome linkage maps for use in composite interval mapping (CIM) to identify QTL. Three QTL were detected in both trials conducted on the 2-49/W21MMT70 population. These were located on chromosomes 1D (QCr.usq-1D.1), 3B (QCr.usq-3B.1) and 7A. QCr.usq-1D.1 and the previously undetected 7A QTL were inherited from 2-49. QCr.usq-3B.1, inherited from W21MMT70, was the most significant of the QTL, explaining up to 40.5% of the phenotypic variance. Three QTL were identified in multiple trials of the Sunco/2-49 population. These were located on chromosomes 1D (QCr.usq-1D.1), 2B (QCr.usq-2B.2) and 4B (QCr.usq-4B.1). Only QCr.usq-2B.2 was inherited from Sunco. QCr.usq-4B.1 was the most significant of these QTL, explaining up to 19.1% of the phenotypic variance. In the 2-49/W21MMT70 population, several DH lines performed significantly better than either parent, with the best recording an average disease severity rating of only 3.8% of that scored by the susceptible check cultivar Puseas. These lines represent a new level of seedling Crown Rot resistance in wheat.

  • Crown Rot of winter cereals: integrating molecular studies and germplasm improvement
    2009
    Co-Authors: Mark W. Sutherland, William D. Bovill, F. Eberhard, A. Lehmensiek, D. J. Herde, S. Simpfendorfer
    Abstract:

    Crown Rot of winter cereals is a major constraint on grain production across most growing regions in Australia, particularly where stubble retention is practiced to maintain soil structure and retain soil water. The predominant cause of this disease is infection with Fusarium pseudograminearum (Fpg), although in some southern areas Fusarium culmorum infections are also significant. These Fusarium species are able to grow saprophytically on stubble remnants over the summer and provide inoculum for crop infection in the following season. Losses due to Crown Rot are highest in seasons featuring a dry finish in which maturing plants experience water stress, with symptoms including basal stem browning and white heads bearing no grain.

  • Identification of novel QTL for resistance to Crown Rot in the doubled haploid wheat population 'W21MMT70' x 'Mendos'
    2006
    Co-Authors: William D. Bovill, G.b. Wildermuth, K. Ritter, B. C. Y. Collard, M. Davis, Mark W. Sutherland
    Abstract:

    Crown Rot (causal agent Fusarium pseudograminearum) is a fungal disease of major significance to wheat cultivation in Australia. A doubled haploid wheat population was produced from a cross between line 'W21MMT70', which displays partial seedling and adult plant (field) resistance to Crown Rot, and 'Mendos', which is moderately susceptible in seedling tests but partially resistant in field trials. Bulked segregant analysis (BSA) based on seedling trial data did not reveal markers for Crown Rot resistance. A framework map was produced consisting of 128 microsatellite markers, four phenotypic markers, and one sequence tagged site marker. To this map 331 previously screened AFLP markers were then added. Three quantitative trait loci (QTL) were identified with composite interval mapping across all of the three seedling trials conducted. These QTL are located on chromosomes 2B, 2D and 5D. The 2D and 5D QTL are inherited from the line 'W21MMT70', whereas the 2B QTL is inherited from 'Mendos'. These loci are different from those associated with Crown Rot resistance in other wheat populations that have been examined, and may represent an opportunity for pyramiding QTL to provide more durable resistance to Crown Rot.

  • Identification of novel QTL for resistance to Crown Rot in the doubled haploid wheat population ‘W21MMT70’ × ‘Mendos’
    Plant Breeding, 2006
    Co-Authors: William D. Bovill, G.b. Wildermuth, K. Ritter, B. C. Y. Collard, M. Davis, Mark W. Sutherland
    Abstract:

    Crown Rot (causal agent Fusarium pseudograminearum) is a fungal disease of major significance to wheat cultivation in Australia. A doubled haploid wheat population was produced from a cross between line ‘W21MMT70’, which displays partial seedling and adult plant (field) resistance to Crown Rot, and ‘Mendos’, which is moderately susceptible in seedling tests but partially resistant in field trials. Bulked segregant analysis (BSA) based on seedling trial data did not reveal markers for Crown Rot resistance. A framework map was produced consisting of 128 microsatellite markers, four phenotypic markers, and one sequence tagged site marker. To this map 331 previously screened AFLP markers were then added. Three quantitative trait loci (QTL) were identified with composite interval mapping across all of the three seedling trials conducted. These QTL are located on chromosomes 2B, 2D and 5D. The 2D and 5D QTL are inherited from the line ‘W21MMT70’, whereas the 2B QTL is inherited from ‘Mendos’. These loci are different from those associated with Crown Rot resistance in other wheat populations that have been examined, and may represent an opportunity for pyramiding QTL to provide more durable resistance to Crown Rot.

  • Strategies for fine mapping QTLs for Crown Rot resistance in wheats
    2005
    Co-Authors: William D. Bovill, G.b. Wildermuth, A. Lehmensiek, B. C. Y. Collard, Mark W. Sutherland
    Abstract:

    [Introduction]: Crown Rot (causal organism Fusarium pseudograminearum) is of great significance to wheat yields within Australia, with losses estimated at $56M per annum. As part of the Australian Winter Cereals Molecular Marker Project (AWCMMP), our group has been responsible for identifying molecular markers for quantitative trait loci (QTLs) that contribute to Crown Rot resistance. Using a number of double-haploid mapping populations, we have identified genomic regions that are associated with resistance. While the markers flanking these QTLs will be of use to breeding programs for marker assisted selection, how these QTLs function in conferring resistance is not understood. This apper outlines QTLs identified in two double-haploid populations, and discusses the use of resistance gene analog (RGA) markers and rice-wheat synteny as strategies that may be helpful for understanding the underlying mechanisms for resistance.