Disease control and its selection for damaging plant virus strains in vegetatively propagated staple food crops; a theoretical assessment

Viral diseases are a key constraint in the production of staple food crops in lesser developed countries. New and improved disease control methods are developed and implemented without consideration of the selective pressure they impose on the virus. In this paper, we analyse the evolution of within-plant virus titre as a response to the implementation of a range of disease control methods. We show that the development of new and improved disease control methods for viral diseases of vegetatively propagated staple food crops ought to take the evolutionary responses of the virus into consideration. Not doing so leads to a risk of failure, which can result in considerable economic losses and increased poverty. Specifically in vitro propagation, diagnostics and breeding methods carry a risk of failure due to the selection for virus strains that build up a high within-plant virus titre. For vegetatively propagated crops, sanitation by roguing has a low risk of failure owing to its combination of selecting for low virus titre strains as well as increasing healthy crop density.

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Selection for Favorable Health Traits: A Potential Approach to Cope with Diseases in Farm Animals

Animals ◽

10.3390/ani10091717 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1717

Author(s):

Guoyu Hu ◽

Duy Ngoc Do ◽

Janine Gray ◽

Younes Miar

Keyword(s):

Disease Control ◽

Animal Welfare ◽

Genomic Selection ◽

Genetic Selection ◽

Farm Animals ◽

Economic Losses ◽

Control Methods ◽

Animal Farming ◽

Eradication Strategy ◽

Selection For

Disease is a global problem for animal farming industries causing tremendous economic losses (>USD 220 billion over the last decade) and serious animal welfare issues. The limitations and deficiencies of current non-selection disease control methods (e.g., vaccination, treatment, eradication strategy, genome editing, and probiotics) make it difficult to effectively, economically, and permanently eliminate the adverse influences of disease in the farm animals. These limitations and deficiencies drive animal breeders to be more concerned and committed to dealing with health problems in farm animals by selecting animals with favorable health traits. Both genetic selection and genomic selection contribute to improving the health of farm animals by selecting certain health traits (e.g., disease tolerance, disease resistance, and immune response), although both of them face some challenges. The objective of this review was to comprehensively review the potential of selecting health traits in coping with issues caused by diseases in farm animals. Within this review, we highlighted that selecting health traits can be applied as a method of disease control to help animal agriculture industries to cope with the adverse influences caused by diseases in farm animals. Certainly, the genetic/genomic selection solution cannot solve all the disease problems in farm animals. Therefore, management, vaccination, culling, medical treatment, and other measures must accompany selection solution to reduce the adverse impact of farm animal diseases on profitability and animal welfare.

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Effect of climate variability on yields of selected staple food crops in northern Ghana

Journal of Agriculture and Food Research ◽

10.1016/j.jafr.2021.100205 ◽

2021 ◽

Vol 6 ◽

pp. 100205

Author(s):

Frank Baffour-Ata ◽

Philip Antwi-Agyei ◽

Elias Nkiaka ◽

Andrew J. Dougill ◽

Alexander K. Anning ◽

...

Keyword(s):

Climate Variability ◽

Northern Ghana ◽

Food Crops ◽

Staple Food

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Comparison of API and Minitek to Center for Disease Control methods for the biochemical characterization of anaerobes

Journal of Clinical Microbiology ◽

10.1128/jcm.4.3.227-231.1976 ◽

1976 ◽

Vol 4 (3) ◽

pp. 227-231 ◽

Cited By ~ 1

Author(s):

S L Hansen ◽

B J Stewart

Keyword(s):

Disease Control ◽

Biochemical Characterization ◽

Clinical Laboratory ◽

Ease Of Use ◽

Gas Liquid Chromatography ◽

Control Methods ◽

Conventional Tests ◽

Reference Strains ◽

Laboratory Time

Two commercially available micromethod multitest systems (API, Analytab Products, Inc., Minitek-Bioquest) were compared with conventional tests suggested by the Center for Disease Control for the identification of anaerobes. Anaerobiosis for the microsystems was achieved using GasPak system (BBL), A total of 175 anaerobes, including 158 clinical isolates and 17 reference strains, were used. Gram morphology, gas-liquid chromatography data, and biochemical reactions from the Center for Disease Control and Virginia Polytechnic Institute anaerobic manuals were used to identify the organisms. The Minitek system included a new anaerobe inoculum broth and two new disks, dextrose without nitrate and nitrate reductase disks. The percentage of correlation of 12 biochemicals using Minitek and 11 biochemicals using the API were compared with the Center for Disease Control reactions. The percentage of correlation of both positive and negative reactions with the API anaerobic strip ranged from 70.8 to 99.4% and with the Minitek from 97.1 to 100%. The microsystems were also evaluated as to the ease of use, adaptabilty to a clinical laboratory, time, and cost.

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Mixtures as a Fungicide Resistance Management Tactic

Phytopathology ◽

10.1094/phyto-04-14-0121-rvw ◽

2014 ◽

Vol 104 (12) ◽

pp. 1264-1273 ◽

Cited By ~ 35

Author(s):

Frank van den Bosch ◽

Neil Paveley ◽

Femke van den Berg ◽

Peter Hobbelen ◽

Richard Oliver

Keyword(s):

At Risk ◽

Disease Control ◽

Fungicide Resistance ◽

Management Strategies ◽

Resistance Management ◽

Relative Effect ◽

Resistance Evolution ◽

Modes Of Action ◽

Selection For ◽

Effective Life

We have reviewed the experimental and modeling evidence on the use of mixtures of fungicides of differing modes of action as a resistance management tactic. The evidence supports the following conclusions. 1. Adding a mixing partner to a fungicide that is at-risk of resistance (without lowering the dose of the at-risk fungicide) reduces the rate of selection for fungicide resistance. This holds for the use of mixing partner fungicides that have either multi-site or single-site modes of action. The resulting predicted increase in the effective life of the at-risk fungicide can be large enough to be of practical relevance. The more effective the mixing partner (due to inherent activity and/or dose), the larger the reduction in selection and the larger the increase in effective life of the at-risk fungicide. 2. Adding a mixing partner while lowering the dose of the at-risk fungicide reduces the selection for fungicide resistance, without compromising effective disease control. The very few studies existing suggest that the reduction in selection is more sensitive to lowering the dose of the at-risk fungicide than to increasing the dose of the mixing partner. 3. Although there are very few studies, the existing evidence suggests that mixing two at-risk fungicides is also a useful resistance management tactic. The aspects that have received too little attention to draw generic conclusions about the effectiveness of fungicide mixtures as resistance management strategies are as follows: (i) the relative effect of the dose of the two mixing partners on selection for fungicide resistance, (ii) the effect of mixing on the effective life of a fungicide (the time from introduction of the fungicide mode of action to the time point where the fungicide can no longer maintain effective disease control), (iii) polygenically determined resistance, (iv) mixtures of two at-risk fungicides, (v) the emergence phase of resistance evolution and the effects of mixtures during this phase, and (vi) monocyclic diseases and nonfoliar diseases. The lack of studies on these aspects of mixture use of fungicides should be a warning against overinterpreting the findings in this review.

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The Potential to Improve Zinc Status through Biofortification of Staple Food Crops with Zinc

Food and Nutrition Bulletin ◽

10.1177/15648265090301s109 ◽

2009 ◽

Vol 30 (1_suppl1) ◽

pp. S172-S178 ◽

Cited By ~ 30

Author(s):

Christine Hotz

Keyword(s):

Food Crops ◽

Zinc Status ◽

Staple Food

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Can High-Risk Fungicides be Used in Mixtures Without Selecting for Fungicide Resistance?

Phytopathology ◽

10.1094/phyto-07-13-0204-r ◽

2014 ◽

Vol 104 (4) ◽

pp. 324-331 ◽

Cited By ~ 22

Author(s):

Alexey Mikaberidze ◽

Bruce A. McDonald ◽

Sebastian Bonhoeffer

Keyword(s):

High Risk ◽

Disease Control ◽

Fungicide Resistance ◽

Fungal Pathogens ◽

Development Of Resistance ◽

Population Dynamics Model ◽

Fungicide Mixtures ◽

Cost Of Resistance ◽

Selection For ◽

Crucial Parameter

Fungicide mixtures produced by the agrochemical industry often contain low-risk fungicides, to which fungal pathogens are fully sensitive, together with high-risk fungicides known to be prone to fungicide resistance. Can these mixtures provide adequate disease control while minimizing the risk for the development of resistance? We present a population dynamics model to address this question. We found that the fitness cost of resistance is a crucial parameter to determine the outcome of competition between the sensitive and resistant pathogen strains and to assess the usefulness of a mixture. If fitness costs are absent, then the use of the high-risk fungicide in a mixture selects for resistance and the fungicide eventually becomes nonfunctional. If there is a cost of resistance, then an optimal ratio of fungicides in the mixture can be found, at which selection for resistance is expected to vanish and the level of disease control can be optimized.

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