87 research outputs found

    Cover crop and conidia delivery system impacts on soil persistence of \u3ci\u3eMetarhizium anisopliae\u3c/i\u3e (Hypocreales: Clavicipitaceae) in sugarbeet

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    The sugarbeet root maggot, Tetanops myopaeformis (Röder), is a major North American pest of sugarbeet, Beta vulgaris L. Previous research suggests that moderate T. myopaeformis control is possible with the entomopathogen Metarhizium anisopliae (Metch.) Sorok. We conducted a three-year (2002‒2004) experiment to assess impacts of oat, Avena sativa L. and rye, Secale cereale L., cover crops on persistence of corn grit-based granular or spray formulations of M. anisopliae isolate ATCC 62176 (i.e. MA 1200) applied at 8 x 1012 viable conidia/ha in sugarbeet. More colony forming units (CFUs) were detected immediately after application [0 days after treatment (DAT)] in spray plots than granule-treated plots. However, 76‒92% declines in CFUs per gram of soil occurred in spray plots within 30 DAT. Substantially (i.e. 83‒560%) more rainfall occurred in June 2002 than during June of any other year. Subsequently, 71‒670% increases in CFU concentrations occurred by 60 DAT in M. anisopliae granuletreated plots with oat or rye cover crops that year. CFU density increases were higher in cover crops in 2002, but no significant cover crop effects were detected. Conidia persisted for up to 30 DAT in M. anisopliae spray plots and 60 DAT in granule-treated plots in 2002; however, no increases occurred in the years with less June rainfall. Trends suggest that M. anisopliae aqueous sprays result in greater conidia concentrations than granules at sugarbeet plant bases in June during T. myopaeformis oviposition and larval establishment on host plants. Increases are possible when delivering conidia via granules, but high post-application rainfall could be necessary for conidia production

    Agronomic Characteristics, Malt Quality, and Disease Resistance of Barley Germplasm Lines with Partial Fusarium Head Blight Resistance

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    Fusarium head blight (FHB), incited by Fusarium graminearum Schwabe, has caused devastating losses in both yield and quality of barley (Hordeum vulgare L.) produced in the northern Great Plains from 1993 to 2003. Thirty-five barley germplasmlines with partial resistance to FHB have been identified in exotic and unadapted germplasm lines. Little is known about their agronomic characteristics, malt quality, and reaction to other diseases as compared to adapted cultivars. This information is needed so barley breeders can make informed decisions when planning crosses involving the resistant germplasm lines. The objective of this study was to compare the agronomic performance, malt quality, and disease reaction of barley germplasm lines with partial FHB resistance to cultivars grown in the northern Great Plains. Agronomic and malting data were collected on the 35 germplasm lines and five check cultivars grown in five environments in North Dakota from 1998 to 2000. Data for FHB severity and deoxynivalenol (DON, a mycotoxin produced by F. graminearum) accumulation were obtained for the same 40 entries grown in FHB-epidemic nurseries in North Dakota from 1997 to 1999. Seedling responses to foliar pathogens common in the northern Great Plains were determined in the greenhouse during fall 1997. None of the FHB-resistant barley germplasm lines had acceptable malt quality for all traits. Kernel plumpness, grain protein concentration, and malt extract were the traits impacted most severely. The FHB-resistant barley germplasm lines headed significantly later than the adapted barley cultivars. Most FHB-resistant germplasm lines were susceptible to the common foliar diseases of the northern Great Plains. At least four cycles of breeding will probably be necessary to develop FHB-resistant germplasm lines acceptable to producers and the malting and brewing industry

    Heritability of Fusarium Head Blight Resistance and Deoxynivalenol Accumulation from Barley Accession CIho 4196

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    Fusarium head blight (FHB), incited by Fusarium graminearum Schwabe [telomorph Gibberella zea (Schwein)], has caused devastating losses to yield and quality of barley (Hordeum vulgare L.) produced in the upper U.S. Midwest from 1993 to 2000. Design of an efficient breeding strategy for developing FHB resistant cultivars is dependent on knowing (i) the heritability of FHB resistance and accumulation of deoxynivalenol (DON), a mycotoxin contaminant produced by F. graminearum and (ii) the correlated response of other traits during selection for reduced FHB. We conducted field studies in FHB disease nurseries using F4:5 and F4:6 families from the cross between the FHB susceptible six-rowed cultivar Foster and the resistant two-rowed accession CIho 4196 to gain knowledge in the areas listed above. Heritability of FHB severity and DON accumulation was 0.65 and 0.46, respectively. A moderately strong positive association between FHB severity and DON accumulation was observed (r = 0.62). FHB severity and DON accumulation were negatively associated with plant height, days to heading, spike angle, and spike density. The selection differentials calculated between the top F4:6 families selected for low FHB severity and the unselected F4:5 families were moderately high for FHB severity, DON accumulation, and days to heading. Less than 14% of the selected lines had six-rowed spikes. No difference in plant height was observed between the selected and unselected families. Thus, development of FHB resistant lines with acceptable DON accumulation and days to heading is obtainable. However, because no lines were as short as Foster, development of FHB resistant plants with acceptable plant height from a cross using CIho 4196 as a parent will be difficult

    Agronomic characteristics, malt quality, and disease resistance of barley germplasm lines with partial Fusarium head blight resistance

    Get PDF
    Fusarium head blight (FHB), incited by Fusarium graminearum Schwabe, has caused devastating losses in both yield and quality of barley (Hordeum vulgare L.) produced in the northern Great Plains from 1993 to 2003. Thirty-five barley germplasm lines with partial resistance to FHB have been identified in exotic and unadapted germplasm lines. Little is known about their agronomic characteristics, malt quality, and reaction to other diseases as compared to adapted cultivars. This information is needed so barley breeders can make informed decisions when planning crosses involving the resistant germplasm lines. The objective of this study was to compare the agronomic performance, malt quality, and disease reaction of barley germplasm lines with partial FHB resistance to cultivars grown in the northern Great Plains. Agronomic and malting data were collected on the 35 germplasm lines and five check cultivars grown in five environments in North Dakota from 1998 to 2000. Data for FHB severity and deoxynivalenol (DON, a mycotoxin produced by F. graminearum) accumulation were obtained for the same 40 entries grown in FHB-epidemic nurseries in North Dakota from 1997 to 1999. Seedling responses to foliar pathogens common in the northern Great Plains were determined in the greenhouse during fall 1997. None of the FHB-resistant barley germplasm lines had acceptable malt quality for all traits. Kernel plumpness, grain protein concentration, and malt extract were the traits impacted most severely. The FHB-resistant barley germplasm lines headed significantly later than the adapted barley cultivars. Most FHB-resistant germplasm lines were susceptible to the common foliar diseases of the northern Great Plains. At least four cycles of breeding will probably be necessary to develop FHB-resistant germplasm lines acceptable to producers and the malting and brewing industry

    Cover crop and conidia delivery system impacts on soil persistence of \u3ci\u3eMetarhizium anisopliae\u3c/i\u3e (Hypocreales: Clavicipitaceae) in sugarbeet

    Get PDF
    The sugarbeet root maggot, Tetanops myopaeformis (Röder), is a major North American pest of sugarbeet, Beta vulgaris L. Previous research suggests that moderate T. myopaeformis control is possible with the entomopathogen Metarhizium anisopliae (Metch.) Sorok. We conducted a three-year (2002‒2004) experiment to assess impacts of oat, Avena sativa L. and rye, Secale cereale L., cover crops on persistence of corn grit-based granular or spray formulations of M. anisopliae isolate ATCC 62176 (i.e. MA 1200) applied at 8 x 1012 viable conidia/ha in sugarbeet. More colony forming units (CFUs) were detected immediately after application [0 days after treatment (DAT)] in spray plots than granule-treated plots. However, 76‒92% declines in CFUs per gram of soil occurred in spray plots within 30 DAT. Substantially (i.e. 83‒560%) more rainfall occurred in June 2002 than during June of any other year. Subsequently, 71‒670% increases in CFU concentrations occurred by 60 DAT in M. anisopliae granuletreated plots with oat or rye cover crops that year. CFU density increases were higher in cover crops in 2002, but no significant cover crop effects were detected. Conidia persisted for up to 30 DAT in M. anisopliae spray plots and 60 DAT in granule-treated plots in 2002; however, no increases occurred in the years with less June rainfall. Trends suggest that M. anisopliae aqueous sprays result in greater conidia concentrations than granules at sugarbeet plant bases in June during T. myopaeformis oviposition and larval establishment on host plants. Increases are possible when delivering conidia via granules, but high post-application rainfall could be necessary for conidia production

    Identification of QTLs Associated with Fusarium Head Blight Resistance in Barley Accession CIho 4196

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    Fusarium head blight (FHB), incited by Fusarium graminearum Schwabe [teleomorph Gibberella zea (Schwein)], reduces quality of harvested barley (Hordeum vulgare L.) because of blighted kernels and the presence of deoxynivalenol (DON), a mycotoxin produced by the pathogen. CIho 4196, a two-rowed type, is one of the most resistant accessions known in barley; however, it possesses many undesirable agronomic traits. To better understand the genetics of reduced FHB severity and DON accumulation conferred by CIho 4196, a genetic map was generated using a population of recombinant inbred lines derived from a cross between Foster (a six-rowed malting cultivar) and CIho 4196. Quantitative trait loci (QTL) analyses were performed using data obtained from 10 field environments. The possible associations of resistance QTLs and various agronomic and morphological traits in barley also were investigated. The centromeric region of chromosome 2H flanked by the markers ABG461C and MWG882A (bins 6–10) likely (P\u3c0.001) contains two QTLs contributing to lower FHB severity and plant height, and one QTL each for DON accumulation, days to heading, and rachis node number. The QTL for low FHB severity in the bin 8 region explained from 3 to 9% of the variation, while the QTL in the bin 10 region explained from 17 to 60% of the variation. A QTL for DON accumulation that explained 9 to 14% of the variation was found in the bin 2 region of chromosome 4H. This may represent a new QTL not present in other FHB resistant sources. Resistance QTLs in the bin 8 region and bin 10 region of chromosome 2HL were provisionally designated Qrgz-2H-8 and Qrgz-2H-10, respectively. The QTL for DON accumulation in chromosome 4H was provisionally named QDON-4H-2

    FielDHub: A shiny app for design of experiments in life sciences

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    FielDHub is an R Shiny design of experiments (DOE) app that aids in the creation of traditional, unreplicated, augmented and partially-replicated (Cullis et al., 2006) designs applied to agriculture, plant breeding, forestry, animal and biological sciences. One of the problems that life scientists often face is the lack of freely available and user-friendly interactive tools to create designs that fit their needs. A few open-source DOE R packages options exist including agricolae (de Mendiburu & Yaseen, 2020) and blocksdesign (Edmondson, 2021), but they require users to be familiar with the R programming language and do not have a graphical user interface (GUI)

    Public health professionals' perceptions toward provision of health protection in England: a survey of expectations of Primary Care Trusts and Health Protection Units in the delivery of health protection

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    BACKGROUND: Effective health protection requires systematised responses with clear accountabilities. In England, Primary Care Trusts and the Health Protection Agency both have statutory responsibilities for health protection. A Memorandum of Understanding identifies responsibilities of both parties, but there is a potential lack of clarity about responsibility for specific health protection functions. We aimed to investigate professionals' perceptions of responsibility for different health protection functions, to inform future guidance for, and organisation of, health protection in England. METHODS: We sent a postal questionnaire to all health protection professionals in England from the following groups: (a) Directors of Public Health in Primary Care Trusts; (b) Directors of Health Protection Units within the Health Protection Agency; (c) Directors of Public Health in Strategic Health Authorities and; (d) Regional Directors of the Health Protection Agency RESULTS: The response rate exceeded 70%. Variations in perceptions of who should be, and who is, delivering health protection functions were observed within, and between, the professional groups (a)-(d). Concordance in views of which organisation should, and which does deliver was high (≥90%) for 6 of 18 health protection functions, but much lower (≤80%) for 6 other functions, including managing the implications of a case of meningitis out of hours, of landfill environmental contamination, vaccination in response to mumps outbreaks, nursing home infection control, monitoring sexually transmitted infections and immunisation training for primary care staff. The proportion of respondents reporting that they felt confident most or all of the time in the safe delivery of a health protection function was strongly correlated with the concordance (r = 0.65, P = 0.0038). CONCLUSION: Whilst we studied professionals' perceptions, rather than actual responses to incidents, our study suggests that there are important areas of health protection where consistent understanding of responsibility for delivery is lacking. There are opportunities to clarify the responsibility for health protection in England, perhaps learning from the approaches used for those health protection functions where we found consistent perceptions of accountability
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