WorldWideScience

Sample records for resistant crop plants

  1. Salt resistant crop plants

    KAUST Repository

    Roy, Stuart J.

    2014-04-01

    Soil salinity is a major constraint to agriculture. To improve salinity tolerance of crops, various traits can be incorporated, including ion exclusion, osmotic tolerance and tissue tolerance. We review the roles of a range of genes involved in salt tolerance traits. Different tissues and cells are adapted for specific and often diverse function, so it is important to express the genes in specific cell-types and to pyramid a range of traits. Modern biotechnology (marker- assisted selection or genetic engineering) needs to be increasingly used to introduce the correct combination of genes into elite crop cultivars. Importantly, the effects of introduced genes need to be evaluated in the field to determine their effect on salinity tolerance and yield improvement.

  2. Genetic engineering of crop plants for fungal resistance: role of antifungal genes.

    Science.gov (United States)

    Ceasar, S Antony; Ignacimuthu, S

    2012-06-01

    Fungal diseases damage crop plants and affect agricultural production. Transgenic plants have been produced by inserting antifungal genes to confer resistance against fungal pathogens. Genes of fungal cell wall-degrading enzymes, such as chitinase and glucanase, are frequently used to produce fungal-resistant transgenic crop plants. In this review, we summarize the details of various transformation studies to develop fungal resistance in crop plants.

  3. Glyphosate Effects on Plant Mineral Nutrition, Crop Rhizosphere Microbiota, and Plant Disease in Glyphosate-Resistant Crops

    Science.gov (United States)

    2012-01-01

    Claims have been made recently that glyphosate-resistant (GR) crops sometimes have mineral deficiencies and increased plant disease. This review evaluates the literature that is germane to these claims. Our conclusions are: (1) although there is conflicting literature on the effects of glyphosate on mineral nutrition on GR crops, most of the literature indicates that mineral nutrition in GR crops is not affected by either the GR trait or by application of glyphosate; (2) most of the available data support the view that neither the GR transgenes nor glyphosate use in GR crops increases crop disease; and (3) yield data on GR crops do not support the hypotheses that there are substantive mineral nutrition or disease problems that are specific to GR crops. PMID:23013354

  4. Plant defense against herbivorous pests: exploiting resistance and tolerance traits for sustainable crop protection

    Directory of Open Access Journals (Sweden)

    Carolyn Mitchell

    2016-07-01

    Full Text Available Interactions between plants and insect herbivores are important determinants of plant productivity in managed and natural vegetation. In response to attack, plants have evolved a range of defenses to reduce the threat of injury and loss of productivity. Crop losses from damage caused by arthropod pests can exceed 15% annually. Crop domestication and selection for improved yield and quality can alter the defensive capability of the crop, increasing reliance on artificial crop protection. Sustainable agriculture, however, depends on reduced chemical inputs. There is an urgent need, therefore, to identify plant defensive traits for crop improvement. Plant defense can be divided into resistance and tolerance strategies. Plant traits that confer herbivore resistance typically prevent or reduce herbivore damage through expression of traits that deter pests from settling, attaching to surfaces, feeding and reproducing, or that reduce palatability. Plant tolerance of herbivory involves expression of traits that limit the negative impact of herbivore damage on productivity and yield. Identifying the defensive traits expressed by plants to deter herbivores or limit herbivore damage, and understanding the underlying defense mechanisms, is crucial for crop scientists to exploit plant defensive traits in crop breeding. In this review, we assess the traits and mechanisms underpinning herbivore resistance and tolerance, and conclude that physical defense traits, plant vigor and herbivore-induced plant volatiles show considerable utility in pest control, along with mixed species crops. We highlight emerging approaches for accelerating the identification of plant defensive traits and facilitating their deployment to improve the future sustainability of crop protection.

  5. Biotechnology: herbicide-resistant crops

    Science.gov (United States)

    Transgenic, herbicide-resistant (HR) crops are planted on about 80% of the land covered by transgenic crops. More than 90% of HR crios are glyphosate-resistant (GR) crops, the others being resistant to glufosinate. The wide-scale adoption of HR crops, largely for economic reasons, has been the mos...

  6. Genetic engineering for increasing fungal and bacterial disease resistance in crop plants.

    Science.gov (United States)

    Wally, Owen; Punja, Zamir K

    2010-01-01

    We review the current and future potential of genetic engineering strategies used to make fungal and bacterial pathogen-resistant GM crops, illustrating different examples of the technologies and the potential benefits and short-falls of the strategies. There are well- established procedures for the production of transgenic plants with resistance towards these pathogens and considerable progress has been made using a range of new methodologies. There are no current commercially available transgenic plant species with increased resistance towards fungal and bacterial pathogens; only plants with increased resistance towards viruses are available. With an improved understanding of plant signaling pathways in response to a range of other pathogens, such as fungi, additional candidate genes for achieving resistance are being investigated. The potential for engineering plants for resistance against individual devastating diseases or for plants with resistance towards multiple pathogens is discussed in detail.

  7. Quantitative Resistance to Plant Pathogens in Pyramiding Strategies for Durable Crop Protection

    Directory of Open Access Journals (Sweden)

    Marie-Laure Pilet-Nayel

    2017-10-01

    Full Text Available Quantitative resistance has gained interest in plant breeding for pathogen control in low-input cropping systems. Although quantitative resistance frequently has only a partial effect and is difficult to select, it is considered more durable than major resistance (R genes. With the exponential development of molecular markers over the past 20 years, resistance QTL have been more accurately detected and better integrated into breeding strategies for resistant varieties with increased potential for durability. This review summarizes current knowledge on the genetic inheritance, molecular basis, and durability of quantitative resistance. Based on this knowledge, we discuss how strategies that combine major R genes and QTL in crops can maintain the effectiveness of plant resistance to pathogens. Combining resistance QTL with complementary modes of action appears to be an interesting strategy for breeding effective and potentially durable resistance. Combining quantitative resistance with major R genes has proven to be a valuable approach for extending the effectiveness of major genes. In the plant genomics era, improved tools and methods are becoming available to better integrate quantitative resistance into breeding strategies. Nevertheless, optimal combinations of resistance loci will still have to be identified to preserve resistance effectiveness over time for durable crop protection.

  8. Genes of Microorganisms: Paving Way to Tailor Next Generation Fungal Disease Resistant Crop Plants

    Directory of Open Access Journals (Sweden)

    Prem L. KASHYAP

    2011-11-01

    Full Text Available The automation of sequencing technologies, flooding in the knowledge of plant-pathogen interactions and advancements in bioinformatics provide tools leading to better knowledge not only of the genome of plant pathogens or microorganism beneficial to plants but also of ways of incorporating genes from microbes into plants as microbial-derived resistance. The identification of various microorganism genes playing key role during pathogensis and the dissection of the signal transduction components of the hypersensitive response and systemic acquired resistance pathways have greatly increased the diversity of options available for tailoring fungus resistant crops. The genetically engineered plants carrying these genes showed spontaneous activation of different defense mechanisms, leading the plant in an elevated state of defense. This defense mode greatly enhances the plants ability to quickly react to a pathogen invasion and more successfully overcome the infection. The aim of this review is to highlight the dynamic use of genes of microorganisms in enhancing crop tolernace towards fungal intruders by examining the most relevant research in this field.

  9. Plant biotechnology: transgenic crops.

    Science.gov (United States)

    Shewry, Peter R; Jones, Huw D; Halford, Nigel G

    2008-01-01

    Transgenesis is an important adjunct to classical plant breeding, in that it allows the targeted manipulation of specific characters using genes from a range of sources. The current status of crop transformation is reviewed, including methods of gene transfer, the selection of transformed plants and control of transgene expression. The application of genetic modification technology to specific traits is then discussed, including input traits relating to crop production (herbicide tolerance and resistance to insects, pathogens and abiotic stresses) and output traits relating to the composition and quality of the harvested organs. The latter include improving the nutritional quality for consumers as well as the improvement of functional properties for food processing.

  10. Comparative Effectiveness of Potential Elicitors of Plant Resistance against Spodoptera frugiperda (J. E. Smith (Lepidoptera: Noctuidae in Four Crop Plants.

    Directory of Open Access Journals (Sweden)

    John W Gordy

    Full Text Available Feeding by insect herbivores activates plant signaling pathways, resulting in the enhanced production of secondary metabolites and other resistance-related traits by injured plants. These traits can reduce insect fitness, deter feeding, and attract beneficial insects. Organic and inorganic chemicals applied as a foliar spray, seed treatment, or soil drench can activate these plant responses. Azelaic acid (AA, benzothiadiazole (BTH, gibberellic acid (GA, harpin, and jasmonic acid (JA are thought to directly mediate plant responses to pathogens and herbivores or to mimic compounds that do. The effects of these potential elicitors on the induction of plant defenses were determined by measuring the weight gains of fall armyworm, Spodoptera frugiperda (J. E. Smith (FAW (Lepidoptera: Noctuidae larvae on four crop plants, cotton, corn, rice, and soybean, treated with the compounds under greenhouse conditions. Treatment with JA consistently reduced growth of FAW reared on treated cotton and soybean. In contrast, FAW fed BTH- and harpin-treated cotton and soybean tissue gained more weight than those fed control leaf tissue, consistent with negative crosstalk between the salicylic acid and JA signaling pathways. No induction or inconsistent induction of resistance was observed in corn and rice. Follow-up experiments showed that the co-application of adjuvants with JA failed to increase the effectiveness of induction by JA and that soybean looper [Chrysodeixis includens (Walker], a relative specialist on legumes, was less affected by JA-induced responses in soybean than was the polyphagous FAW. Overall, the results of these experiments demonstrate that the effectiveness of elicitors as a management tactic will depend strongly on the identities of the crop, the pest, and the elicitor involved.

  11. Host plant resistance to aphids in cultivated crops: genetic and molecular bases, and interactions with aphid populations.

    Science.gov (United States)

    Dogimont, Catherine; Bendahmane, Abdelhafid; Chovelon, Véronique; Boissot, Nathalie

    2010-01-01

    Host plant resistance is an efficient and environmentally friendly means of controlling insects, including aphids, but resistant-breaking biotypes have occurred in several plant-aphid systems. Our review of the genetic and molecular bases of aphid resistance in crop species emphasizes the limited number of aphid resistance genes and alleles. Inheritance of aphid resistance may be monogenic (dominant or recessive genes) or polygenic. Two dominant, aphid resistance genes have been isolated to date. They both encode NBS-LRR proteins involved in the specific recognition of aphids. Strategies to ensure aphid resistance effectiveness and durability are discussed. Innovative research activities are proposed. Copyright 2010 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  12. Plant adaptation to acid soils: the molecular basis for crop aluminum resistance

    Science.gov (United States)

    Aluminum (Al) toxicity on acid soils is a significant limitation to crop production worldwide, as approximately 50% of the world’s potentially arable soils are acidic. Because acid soils are such an important constraint to agriculture, understanding the mechanisms and genes conferring resistance to ...

  13. Plant senescence and crop productivity

    DEFF Research Database (Denmark)

    Gregersen, Per L.; Culetic, Andrea; Boschian, Luca

    2013-01-01

    Senescence is a developmental process which in annual crop plants overlaps with the reproductive phase. Senescence might reduce crop yield when it is induced prematurely under adverse environmental conditions. This review covers the role of senescence for the productivity of crop plants. With the......Senescence is a developmental process which in annual crop plants overlaps with the reproductive phase. Senescence might reduce crop yield when it is induced prematurely under adverse environmental conditions. This review covers the role of senescence for the productivity of crop plants....... With the aim to enhance productivity, a number of functional stay-green cultivars have been selected by conventional breeding, in particular of sorghum and maize. In many cases, a positive correlation between leaf area duration and yield has been observed, although in a number of other cases, stay......-green cultivars do not display significant effects with regards to productivity. In several crops, the stay-green phenotype is observed to be associated with a higher drought resistance and a better performance under low nitrogen conditions. Among the approaches used to achieve stay-green phenotypes in transgenic...

  14. Plant Fitness Assessment for Wild Relatives of Insect Resistant Bt-Crops

    Directory of Open Access Journals (Sweden)

    D. K. Letourneau

    2012-01-01

    Full Text Available When field tests of transgenic plants are precluded by practical containment concerns, manipulative experiments can detect potential consequences of crop-wild gene flow. Using topical sprays of bacterial Bacillus thuringiensis larvicide (Bt and larval additions, we measured fitness effects of reduced herbivory on Brassica rapa (wild mustard and Raphanus sativus (wild radish. These species represent different life histories among the potential recipients of Bt transgenes from Bt cole crops in the US and Asia, for which rare spontaneous crosses are expected under high exposure. Protected wild radish and wild mustard seedlings had approximately half the herbivore damage of exposed plants and 55% lower seedling mortality, resulting in 27% greater reproductive success, 14-day longer life-spans, and 118% more seeds, on average. Seed addition experiments in microcosms and in situ indicated that wild radish was more likely to spread than wild mustard in coastal grasslands.

  15. Induced plant resistance as a pest management tactic on piercing sucking insects of sesame crop

    Directory of Open Access Journals (Sweden)

    M. F. Mahmoud

    2013-09-01

    Full Text Available Sesame, Sesamum indicum L. is the most oil seed crop of the world and also a major oil seed crop of Egypt. One of the major constraints in its production the damage caused by insect pests, particularly sucking insects which suck the cell sap from leaves, flowers and capsules. Impact of three levels of potassin-F, salicylic acid and combination between them on reduction infestation of Stink bug Nezara viridula L., Mirid bug Creontiades sp., Green peach aphid Myzus persicae (Sulzer, Leafhopper Empoasca lybica de Berg and Whitefly Bemisia tabaci (Gennadius of sesame crop cultivar Shandawil 3 was carried out during 2010-2011 crop season at Experimental farm, Faculty of Agriculture, Suez Canal University, Ismailia, Egypt. Also, the impacts of potassin-F and salicylic acid on yield production of sesame were studied. Results indicated that percent of reduction of infestation by N. viridula, M. persicae, Creontiades sp., E. lybicae, B. tabaci and phyllody disease were significantly higher at Level 2 (Potassin-F= 2.5 cm/l, Salicylic acid= 0.001 M and Potassin + Salicylic= 2.5 cm/l + 0.001 M and consequently higher seed yield per plant were obtained.

  16. Transgenic Crops for Herbicide Resistance

    Science.gov (United States)

    Since their introduction in 1995, crops made resistant to the broad-spectrum herbicides glyphosate and glufosinate with transgenes are widely available and used in much of the world. As of 2008, over 80% of the transgenic crops grown world-wide have this transgenic trait. This technology has had m...

  17. SALT TOLERANCE OF CROP PLANTS

    OpenAIRE

    Hamdia, M. A; Shaddad, M. A. K.

    2010-01-01

    Several environmental factors adversely affect plant growth and development and final yield performance of a crop. Drought, salinity, nutrient imbalances (including mineral toxicities and deficiencies) and extremes of temperature are among the major environmental constraints to crop productivity worldwide. Development of crop plants with stress tolerance, however, requires, among others, knowledge of the physiological mechanisms and genetic controls of the contributing traits at different pla...

  18. Engineered plant virus resistance.

    Science.gov (United States)

    Galvez, Leny C; Banerjee, Joydeep; Pinar, Hasan; Mitra, Amitava

    2014-11-01

    Virus diseases are among the key limiting factors that cause significant yield loss and continuously threaten crop production. Resistant cultivars coupled with pesticide application are commonly used to circumvent these threats. One of the limitations of the reliance on resistant cultivars is the inevitable breakdown of resistance due to the multitude of variable virus populations. Similarly, chemical applications to control virus transmitting insect vectors are costly to the farmers, cause adverse health and environmental consequences, and often result in the emergence of resistant vector strains. Thus, exploiting strategies that provide durable and broad-spectrum resistance over diverse environments are of paramount importance. The development of plant gene transfer systems has allowed for the introgression of alien genes into plant genomes for novel disease control strategies, thus providing a mechanism for broadening the genetic resources available to plant breeders. Genetic engineering offers various options for introducing transgenic virus resistance into crop plants to provide a wide range of resistance to viral pathogens. This review examines the current strategies of developing virus resistant transgenic plants. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  19. SALT TOLERANCE OF CROP PLANTS

    Directory of Open Access Journals (Sweden)

    Hamdia, M. A

    2010-09-01

    Full Text Available Several environmental factors adversely affect plant growth and development and final yield performance of a crop. Drought, salinity, nutrient imbalances (including mineral toxicities and deficiencies and extremes of temperature are among the major environmental constraints to crop productivity worldwide. Development of crop plants with stress tolerance, however, requires, among others, knowledge of the physiological mechanisms and genetic controls of the contributing traits at different plant developmental stages. In the past 2 decades, biotechnology research has provided considerable insights into the mechanism of biotic stress tolerance in plants at the molecular level. Furthermore, different abiotic stress factors may provoke osmotic stress, oxidative stress and protein denaturation in plants, which lead to similar cellular adaptive responses such as accumulation of compatible solutes, induction of stress proteins, and acceleration of reactive oxygen species scavenging systems. Recently, the authores try to improve plant tolerance to salinity injury through either chemical treatments (plant hormones, minerals, amino acids, quaternary ammonium compounds, polyamines and vitamins or biofertilizers treatments (Asymbiotic nitrogen-fixing bacteria, symbiotic nitrogen-fixing bacteria and mycorrhiza or enhanced a process used naturally by plants to minimise the movement of Na+ to the shoot, using genetic modification to amplify the process, helping plants to do what they already do - but to do it much better."

  20. in crop plants

    Directory of Open Access Journals (Sweden)

    Jan Antoni Rafalski

    2017-05-01

    Full Text Available Most important crop productivity traits, such as yield under normal and environmental stress conditions, are determined by a large number of genes, each with a small phenotypic effect. Genetic improvement of these traits through breeding or genetic engineering has been frustrating researchers in academia and industry. The reasons for this include the complexity of the traits, the difficulty of precise phenotyping and the lack of validated candidate genes. Different approaches to the discovery of the genetic architecture of such traits, such as Genetic Association Mapping and Genomic Selection and their engineering, are expected to yield benefits for farmers and consumers.

  1. Botrytis pseudocinerea Is a Significant Pathogen of Several Crop Plants but Susceptible to Displacement by Fungicide-Resistant B. cinerea Strains.

    Science.gov (United States)

    Plesken, Cecilia; Weber, Roland W S; Rupp, Sabrina; Leroch, Michaela; Hahn, Matthias

    2015-10-01

    Botrytis cinerea is one of the most important pathogens worldwide, causing gray mold on a large variety of crops. Botrytis pseudocinerea has been found previously to occur together with B. cinerea in low abundance in vineyards and strawberry fields. Here, we report B. pseudocinerea to be common and sometimes dominant over B. cinerea on several fruit and vegetable crops in Germany. On apples with calyx end rot and on oilseed rape, it was the major gray mold species. Abundance of B. pseudocinerea was often negatively correlated with fungicide treatments. On cultivated strawberries, it was frequently found in spring but was largely displaced by B. cinerea following fungicide applications. Whereas B. cinerea strains with multiple-fungicide resistance were common in these fields, B. pseudocinerea almost never developed resistance to any fungicide even though resistance mutations occurred at similar frequencies in both species under laboratory conditions. The absence of resistance to quinone outside inhibitors in B. pseudocinerea was correlated with an intron in cytB preventing the major G143A resistance mutation. Our work indicates that B. pseudocinerea has a wide host range similar to that of B. cinerea and that it can become an important gray mold pathogen on cultivated plants. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  2. Botrytis pseudocinerea Is a Significant Pathogen of Several Crop Plants but Susceptible to Displacement by Fungicide-Resistant B. cinerea Strains

    Science.gov (United States)

    Plesken, Cecilia; Weber, Roland W. S.; Rupp, Sabrina; Leroch, Michaela

    2015-01-01

    Botrytis cinerea is one of the most important pathogens worldwide, causing gray mold on a large variety of crops. Botrytis pseudocinerea has been found previously to occur together with B. cinerea in low abundance in vineyards and strawberry fields. Here, we report B. pseudocinerea to be common and sometimes dominant over B. cinerea on several fruit and vegetable crops in Germany. On apples with calyx end rot and on oilseed rape, it was the major gray mold species. Abundance of B. pseudocinerea was often negatively correlated with fungicide treatments. On cultivated strawberries, it was frequently found in spring but was largely displaced by B. cinerea following fungicide applications. Whereas B. cinerea strains with multiple-fungicide resistance were common in these fields, B. pseudocinerea almost never developed resistance to any fungicide even though resistance mutations occurred at similar frequencies in both species under laboratory conditions. The absence of resistance to quinone outside inhibitors in B. pseudocinerea was correlated with an intron in cytB preventing the major G143A resistance mutation. Our work indicates that B. pseudocinerea has a wide host range similar to that of B. cinerea and that it can become an important gray mold pathogen on cultivated plants. PMID:26231644

  3. Engineering disease resistance in plants

    NARCIS (Netherlands)

    Custers, J.H.H.V.

    2007-01-01

    The genetic engineering of plants for increased pathogen resistance has engaged researchers and companies for decades. Until now, thenumberof crops with genetically engineered disease resistance traits which have entered the market are limited to products displaying virus

  4. Engineering insect-resistant crops: A review

    African Journals Online (AJOL)

    dgeorge

    Insect pests cause significant damage to crops world-wide. This is despite integrated pest management strategies combining such control measures as chemical control, use of resistant varieties and other measures. Other control measures such as use of genetically modified crops are being adopted. Transgenic crops ...

  5. The benefits of herbicide-resistant crops.

    Science.gov (United States)

    Green, Jerry M

    2012-10-01

    Since 1996, genetically modified herbicide-resistant crops, primarily glyphosate-resistant soybean, corn, cotton and canola, have helped to revolutionize weed management and have become an important tool in crop production practices. Glyphosate-resistant crops have enabled the implementation of weed management practices that have improved yield and profitability while better protecting the environment. Growers have recognized their benefits and have made glyphosate-resistant crops the most rapidly adopted technology in the history of agriculture. Weed management systems with glyphosate-resistant crops have often relied on glyphosate alone, have been easy to use and have been effective, economical and more environmentally friendly than the systems they have replaced. Glyphosate has worked extremely well in controlling weeds in glyphosate-resistant crops for more than a decade, but some key weeds have evolved resistance, and using glyphosate alone has proved unsustainable. Now, growers need to renew their weed management practices and use glyphosate with other cultural, mechanical and herbicide options in integrated systems. New multiple-herbicide-resistant crops with resistance to glyphosate and other herbicides will expand the utility of existing herbicide technologies and will be an important component of future weed management systems that help to sustain the current benefits of high-efficiency and high-production agriculture. Copyright © 2012 Society of Chemical Industry.

  6. Protein improvement in crop plants

    International Nuclear Information System (INIS)

    Rabson, R.

    1974-01-01

    There are compelling reasons for attempting to increase the quality and quantity of protein available in crop plants through plant breeding, despite the fact that some critics have argued that no worldwide protein shortage exists. What used to be thought of as a 'protein gap' has now come to be considered in terms of protein-calorie malnutrition. This is only right since protein and calorie nutrition are inextricable. t the moment there are still unanswered questions as to the precise protein requirements of humans as a function of age, health and ambient conditions. There are, in addition, some indications that the incidence of Kwashiorkor (protein deficiency disease) is increasing in different parts of the world. At a recent meeting of the Protein Advisory Group of the United Nations System, Dr. Jean Mayer, an eminent human nutritionist of Harvard University, U.S.A., indicated the reasons for concern for the current food situation generally, and the protein food supply in particular. These factors include: - Immoderate continuing human population increases, most pronounced in some poor developing countries. - The highly accelerated consumption of animal foods associated with increasing affluence in the richer countries of the world. The production of such foods as meat demands great expenditures of grain, which is an inefficient mode of obtaining the required calories and protein for human consumption. - The over-exploitation of many of the world's fishery resources resulting in reduced yields, perhaps irreversibly, of some fishes. - Recent price increases in petroleum and fertilizer products which have imposed a major obstacle to increasing crop production. - The apparent alteration of climates in places like Africa, Asia and other parts of the Northern hemisphere which may put significant restrictions on crop production. hey are cogent reasons to be seriously concerned about these matters. (author)

  7. Engineering Sclerotinia Sclerotiorum Resistance in Oilseed Crops ...

    African Journals Online (AJOL)

    The fungal pathogen Sclerotinia sclerotiorum (Lib.) de Bary is worldwide in distribution and pathogenic to more than 400 plant species. This disease causes significant yield losses of various important crops including sunflower, canola, and soybean. Applying fungicides and crop rotation are currently the major methods of ...

  8. Can pyramids and seed mixtures delay resistance to Bt crops?

    Science.gov (United States)

    The primary strategy for delaying evolution of pest resistance to transgenic crops that produce insecticidal proteins from Bacillus thuringiensis (Bt) entails refuges of plants that do not produce Bt toxins and thus allow survival of susceptible pests. Recent advances include using refuges together...

  9. Resistance Genes in Global Crop Breeding Networks.

    Science.gov (United States)

    Garrett, K A; Andersen, K F; Asche, F; Bowden, R L; Forbes, G A; Kulakow, P A; Zhou, B

    2017-10-01

    Resistance genes are a major tool for managing crop diseases. The networks of crop breeders who exchange resistance genes and deploy them in varieties help to determine the global landscape of resistance and epidemics, an important system for maintaining food security. These networks function as a complex adaptive system, with associated strengths and vulnerabilities, and implications for policies to support resistance gene deployment strategies. Extensions of epidemic network analysis can be used to evaluate the multilayer agricultural networks that support and influence crop breeding networks. Here, we evaluate the general structure of crop breeding networks for cassava, potato, rice, and wheat. All four are clustered due to phytosanitary and intellectual property regulations, and linked through CGIAR hubs. Cassava networks primarily include public breeding groups, whereas others are more mixed. These systems must adapt to global change in climate and land use, the emergence of new diseases, and disruptive breeding technologies. Research priorities to support policy include how best to maintain both diversity and redundancy in the roles played by individual crop breeding groups (public versus private and global versus local), and how best to manage connectivity to optimize resistance gene deployment while avoiding risks to the useful life of resistance genes. [Formula: see text] Copyright © 2017 The Author(s). This is an open access article distributed under the CC BY 4.0 International license .

  10. Achieving durable resistance against plant diseases

    NARCIS (Netherlands)

    Lof, Marjolein Elisabeth; Vallavieille-Pope, de Claude; Werf, van der Wopke

    2017-01-01

    Genetic resistance in crops is a cornerstone of disease management in agriculture. Such genetic resistance is often rapidly broken due to selection for virulence in the pathogen population. Here, we ask whether there are strategies that can prolong the useful life of plant resistance genes. In a

  11. Molecular basis for the herbicide resistance of Roundup Ready crops

    OpenAIRE

    Funke, Todd; Han, Huijong; Healy-Fried, Martha L.; Fischer, Markus; Schönbrunn, Ernst

    2006-01-01

    The engineering of transgenic crops resistant to the broad-spectrum herbicide glyphosate has greatly improved agricultural efficiency worldwide. Glyphosate-based herbicides, such as Roundup, target the shikimate pathway enzyme 5-enolpyruvylshikimate 3-phosphate (EPSP) synthase, the functionality of which is absolutely required for the survival of plants. Roundup Ready plants carry the gene coding for a glyphosate-insensitive form of this enzyme, obtained from Agrobacterium sp. strain CP4. Onc...

  12. Fungicide impacts on photosynthesis in crop plants.

    Science.gov (United States)

    Petit, Anne-Noëlle; Fontaine, Florence; Vatsa, Parul; Clément, Christophe; Vaillant-Gaveau, Nathalie

    2012-03-01

    Fungicides are widely used to control pests in crop plants. However, it has been reported that these pesticides may have negative effects on crop physiology, especially on photosynthesis. An alteration in photosynthesis might lead to a reduction in photoassimilate production, resulting in a decrease in both growth and yield of crop plants. For example, a contact fungicide such as copper inhibits photosynthesis by destroying chloroplasts, affecting photosystem II activity and chlorophyll biosynthesis. Systemic fungicides such as benzimidazoles, anilides, and pyrimidine are also phytotoxic, whereas azoles stimulate photosynthesis. This article focuses on the available information about toxic effects of fungicides on photosynthesis in crop plants, highlighting the mechanisms of perturbation, interaction, and the target sites of different classes of fungicides. © Springer Science+Business Media B.V. 2012

  13. Engineering resistance to plant viruses: Present status and future prospects

    Science.gov (United States)

    Plant viruses cause severe crop losses across the globe. Resistant cultivars together with pesticide application are commonly used to avoid the losses caused by plant viruses. However, very limited success has been achieved at diminishing the impact of plant viruses. Use of virus resistant plant is ...

  14. Metabolism-based herbicide resistance and cross-resistance in crop weeds: a threat to herbicide sustainability and global crop production.

    Science.gov (United States)

    Yu, Qin; Powles, Stephen

    2014-11-01

    Weedy plant species that have evolved resistance to herbicides due to enhanced metabolic capacity to detoxify herbicides (metabolic resistance) are a major issue. Metabolic herbicide resistance in weedy plant species first became evident in the 1980s in Australia (in Lolium rigidum) and the United Kingdom (in Alopecurus myosuroides) and is now increasingly recognized in several crop-weed species as a looming threat to herbicide sustainability and thus world crop production. Metabolic resistance often confers resistance to herbicides of different chemical groups and sites of action and can extend to new herbicide(s). Cytochrome P450 monooxygenase, glycosyl transferase, and glutathione S-transferase are often implicated in herbicide metabolic resistance. However, precise biochemical and molecular genetic elucidation of metabolic resistance had been stalled until recently. Complex cytochrome P450 superfamilies, high genetic diversity in metabolic resistant weedy plant species (especially cross-pollinated species), and the complexity of genetic control of metabolic resistance have all been barriers to advances in understanding metabolic herbicide resistance. However, next-generation sequencing technologies and transcriptome-wide gene expression profiling are now revealing the genes endowing metabolic herbicide resistance in plants. This Update presents an historical review to current understanding of metabolic herbicide resistance evolution in weedy plant species. © 2014 American Society of Plant Biologists. All Rights Reserved.

  15. Molecular basis for the herbicide resistance of Roundup Ready crops.

    Science.gov (United States)

    Funke, Todd; Han, Huijong; Healy-Fried, Martha L; Fischer, Markus; Schönbrunn, Ernst

    2006-08-29

    The engineering of transgenic crops resistant to the broad-spectrum herbicide glyphosate has greatly improved agricultural efficiency worldwide. Glyphosate-based herbicides, such as Roundup, target the shikimate pathway enzyme 5-enolpyruvylshikimate 3-phosphate (EPSP) synthase, the functionality of which is absolutely required for the survival of plants. Roundup Ready plants carry the gene coding for a glyphosate-insensitive form of this enzyme, obtained from Agrobacterium sp. strain CP4. Once incorporated into the plant genome, the gene product, CP4 EPSP synthase, confers crop resistance to glyphosate. Although widely used, the molecular basis for this glyphosate-resistance has remained obscure. We generated a synthetic gene coding for CP4 EPSP synthase and characterized the enzyme using kinetics and crystallography. The CP4 enzyme has unexpected kinetic and structural properties that render it unique among the known EPSP synthases. Glyphosate binds to the CP4 EPSP synthase in a condensed, noninhibitory conformation. Glyphosate sensitivity can be restored through a single-site mutation in the active site (Ala-100-Gly), allowing glyphosate to bind in its extended, inhibitory conformation.

  16. Metabolism-Based Herbicide Resistance and Cross-Resistance in Crop Weeds: A Threat to Herbicide Sustainability and Global Crop Production1

    Science.gov (United States)

    Yu, Qin; Powles, Stephen

    2014-01-01

    Weedy plant species that have evolved resistance to herbicides due to enhanced metabolic capacity to detoxify herbicides (metabolic resistance) are a major issue. Metabolic herbicide resistance in weedy plant species first became evident in the 1980s in Australia (in Lolium rigidum) and the United Kingdom (in Alopecurus myosuroides) and is now increasingly recognized in several crop-weed species as a looming threat to herbicide sustainability and thus world crop production. Metabolic resistance often confers resistance to herbicides of different chemical groups and sites of action and can extend to new herbicide(s). Cytochrome P450 monooxygenase, glycosyl transferase, and glutathione S-transferase are often implicated in herbicide metabolic resistance. However, precise biochemical and molecular genetic elucidation of metabolic resistance had been stalled until recently. Complex cytochrome P450 superfamilies, high genetic diversity in metabolic resistant weedy plant species (especially cross-pollinated species), and the complexity of genetic control of metabolic resistance have all been barriers to advances in understanding metabolic herbicide resistance. However, next-generation sequencing technologies and transcriptome-wide gene expression profiling are now revealing the genes endowing metabolic herbicide resistance in plants. This Update presents an historical review to current understanding of metabolic herbicide resistance evolution in weedy plant species. PMID:25106819

  17. Progress and challenges for abiotic stress proteomics of crop plants.

    Science.gov (United States)

    Barkla, Bronwyn J; Vera-Estrella, Rosario; Pantoja, Omar

    2013-06-01

    Plants are continually challenged to recognize and respond to adverse changes in their environment to avoid detrimental effects on growth and development. Understanding the mechanisms that crop plants employ to resist and tolerate abiotic stress is of considerable interest for designing agriculture breeding strategies to ensure sustainable productivity. The application of proteomics technologies to advance our knowledge in crop plant abiotic stress tolerance has increased dramatically in the past few years as evidenced by the large amount of publications in this area. This is attributed to advances in various technology platforms associated with MS-based techniques as well as the accessibility of proteomics units to a wider plant research community. This review summarizes the work which has been reported for major crop plants and evaluates the findings in context of the approaches that are widely employed with the aim to encourage broadening the strategies used to increase coverage of the proteome. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Crop plants as models for understanding plant adaptation and diversification

    Science.gov (United States)

    Olsen, Kenneth M.; Wendel, Jonathan F.

    2013-01-01

    Since the time of Darwin, biologists have understood the promise of crop plants and their wild relatives for providing insight into the mechanisms of phenotypic evolution. The intense selection imposed by our ancestors during plant domestication and subsequent crop improvement has generated remarkable transformations of plant phenotypes. Unlike evolution in natural settings, descendent and antecedent conditions for crop plants are often both extant, providing opportunities for direct comparisons through crossing and other experimental approaches. Moreover, since domestication has repeatedly generated a suite of “domestication syndrome” traits that are shared among crops, opportunities exist for gaining insight into the genetic and developmental mechanisms that underlie parallel adaptive evolution. Advances in our understanding of the genetic architecture of domestication-related traits have emerged from combining powerful molecular technologies with advanced experimental designs, including nested association mapping, genome-wide association studies, population genetic screens for signatures of selection, and candidate gene approaches. These studies may be combined with high-throughput evaluations of the various “omics” involved in trait transformation, revealing a diversity of underlying causative mutations affecting phenotypes and their downstream propagation through biological networks. We summarize the state of our knowledge of the mutational spectrum that generates phenotypic novelty in domesticated plant species, and our current understanding of how domestication can reshape gene expression networks and emergent phenotypes. An exploration of traits that have been subject to similar selective pressures across crops (e.g., flowering time) suggests that a diversity of targeted genes and causative mutational changes can underlie parallel adaptation in the context of crop evolution. PMID:23914199

  19. Crop plants as models for understanding plant adaptation and diversification

    Directory of Open Access Journals (Sweden)

    Kenneth M Olsen

    2013-08-01

    Full Text Available Since the time of Darwin, biologists have understood the promise of crop plants and their wild relatives for providing insight into the mechanisms of phenotypic evolution. The intense selection imposed by our ancestors during plant domestication and subsequent crop improvement has generated remarkable transformations of plant phenotypes. Unlike evolution in natural settings, descendent and antecedent conditions for crop plants are often both extant, providing opportunities for direct comparisons through crossing and other experimental approaches. Moreover, since domestication has repeatedly generated a suite of domestication syndrome traits that are shared among crops, opportunities exist for gaining insight into the genetic and developmental mechanisms that underlie parallel adaptive evolution. Advances in our understanding of the genetic architecture of domestication-related traits have emerged from combining powerful molecular technologies with advanced experimental designs, including nested association mapping, genome-wide association studies, population genetic screens for signatures of selection, and candidate gene approaches. These studies may be combined with high-throughput evaluations of the various omics involved in trait transformation, revealing a diversity of underlying causative mutations affecting phenotypes and their downstream propagation through biological networks. We summarize the state of our knowledge of the mutational spectrum that generates phenotypic novelty in domesticated plant species, and our current understanding of how domestication can reshape gene expression networks and emergent phenotypes. An exploration of traits that have been subject to similar selective pressures across crops (e.g., flowering time suggests that a diversity of targeted genes and causative mutational changes can underlie parallel adaptation in the context of crop evolution.

  20. Trade-Offs in Arbuscular Mycorrhizal Symbiosis: Disease Resistance, Growth Responses and Perspectives for Crop Breeding

    Directory of Open Access Journals (Sweden)

    Catherine N. Jacott

    2017-11-01

    Full Text Available There is an increasing need to develop high-yielding, disease-resistant crops and reduce fertilizer usage. Combining disease resistance with efficient nutrient assimilation through improved associations with symbiotic microorganisms would help to address this. Arbuscular mycorrhizal fungi (AMF form symbiotic relationships with most terrestrial plants, resulting in nutritional benefits and the enhancement of stress tolerance and disease resistance. Despite these advantages, arbuscular mycorrhizal (AM interactions are not normally directly considered in plant breeding. Much of our understanding of the mechanisms of AM symbiosis comes from model plants, which typically exhibit positive growth responses. However, applying this knowledge to crops has not been straightforward. In many crop plants, phosphate uptake and growth responses in AM-colonized plants are variable, with AM plants exhibiting sometimes zero or negative growth responses and lower levels of phosphate acquisition. Host plants must also balance the ability to host AMF with the ability to resist pathogens. Advances in understanding the plant immune system have revealed similarities between pathogen infection and AM colonization that may lead to trade-offs between symbiosis and disease resistance. This review considers the potential trade-offs between AM colonization, agronomic traits and disease resistance and highlights the need for translational research to apply fundamental knowledge to crop improvement.

  1. Engineering insect-resistant crops: A review | George | African ...

    African Journals Online (AJOL)

    Insect pests cause significant damage to crops world-wide. This is despite integrated pest management strategies combining such control measures as chemical control, use of resistant varieties and other measures. Other control measures such as use of genetically modified crops are being adopted. Transgenic crops ...

  2. Glyphosate-resistant crops: adoption, use and future considerations.

    Science.gov (United States)

    Dill, Gerald M; Cajacob, Claire A; Padgette, Stephen R

    2008-04-01

    Glyphosate-resistant crops (GRCs) were first introduced in the United States in soybeans in 1996. Adoption has been very rapid in soybeans and cotton since introduction and has grown significantly in maize in recent years. GRCs have grown to over 74 million hectares in five crop species in 13 countries. The intent of this paper is to update the hectares planted and the use patterns of GRC globally, and to discuss briefly future applications and uses of the technology. The largest land areas of GRCs are occupied by soybean (54.2 million ha), maize (13.2 million ha), cotton (5.1 million ha), canola (2.3 million ha) and alfalfa (0.1 million ha). Currently, the USA, Argentina, Brazil and Canada have the largest plantings of GRCs. Herbicide use patterns would indicate that over 50% of glyphosate-resistant (GR) maize hectares and 70% of GR cotton hectares receive alternative mode-of-action treatments, while approximately 25% of GR soybeans receive such a treatment in the USA. Alternative herbicide use is likely driven by both agronomic need and herbicide resistance limitations in certain GR crops such as current GR cotton. Tillage practices in the USA indicate that > 65% of GR maize hectares, 70% of GR cotton hectares and 50% of GR soybean hectares received some tillage in the production system. Tillage was likely used for multiple purposes ranging from seed-bed preparation to weed management. GRCs represent one of the more rapidly adopted weed management technologies in recent history. Current use patterns would indicate that GRCs will likely continue to be a popular weed management choice that may also include the use of other herbicides to complement glyphosate. Stacking with other biotechnology traits will also give farmers the benefits and convenience of multiple pest control and quality trait technologies within a single seed. Copyright (c) 2007 Society of Chemical Industry.

  3. Coping mechanisms for crop plants in drought-prone environments.

    Science.gov (United States)

    Neumann, Peter M

    2008-05-01

    Drought is a major limitation to plant productivity. Various options are available for increasing water availability and sustaining growth of crop plants in drought-prone environments. After a general introduction to the problems of water availability, this review focuses on a critical evaluation of recent progress in unravelling mechanisms for modifying plant growth responses to drought. Investigations of key regulatory mechanisms integrating plant growth responses to water deficits at the whole-organism, cellular and genomic levels continue to provide novel and exiting research findings. For example, recent reports contradict the widespread conception that root-derived abscisic acid is necessarily involved in signalling for stomatal and shoot-growth responses to soil water deficits. The findings bring into question the theoretical basis for alternate-side root-irrigation techniques. Similarly, recent reports indicate that increased ABA production or increased aquaporin expression did not lead to improved drought resistance. Other reports have concerned key genes and proteins involved in regulation of flowering (FT), vegetative growth (DELLA), leaf senescence (IPT) and desiccation tolerance (LEA). Introgression of such genes, with suitable promoters, can greatly impact on whole-plant responses to drought. Further developments could facilitate the introduction by breeders of new crop varieties with growth physiologies tailored to improved field performance under drought. Parallel efforts to encourage the introduction of supplementary irrigation with water made available by improved conservation measures and by sea- or brackish-water desalination, will probably provide comprehensive solutions to coping with drought-prone environments.

  4. Plant Domestication and Resistance to Herbivory

    Science.gov (United States)

    2013-01-01

    Transformation of wild species into elite cultivars through “domestication” entails evolutionary responses in which plant populations adapt to selection. Domestication is a process characterized by the occurrence of key mutations in morphological, phenological, or utility genes, which leads to the increased adaptation and use of the plant; however, this process followed by modern plant breeding practices has presumably narrowed the genetic diversity in crop plants. The reduction of genetic diversity could result in “broad susceptibility” to newly emerging herbivores and pathogens, thereby threatening long-term crop retention. Different QTLs influencing herbivore resistance have also been identified, which overlap with other genes of small effect regulating resistance indicating the presence of pleiotropism or linkage between such genes. However, this reduction in genetic variability could be remunerated by introgression of novel traits from wild perhaps with antifeedant and antinutritional toxic components. Thus it is strongly believed that transgenic technologies may provide a radical and promising solution to combat herbivory as these avoid linkage drag and also the antifeedant angle. Here, important questions related to the temporal dynamics of resistance to herbivory and intricate genetic phenomenon with their impact on crop evolution are addressed and at times hypothesized for future validation. PMID:23589713

  5. Uranium uptake by hydroponically cultivated crop plants

    Energy Technology Data Exchange (ETDEWEB)

    Soudek, Petr; Petrova, Sarka [Laboratory of Plant Biotechnologies, Joint Laboratory of Institute of Experimental Botany AS CR, v.v.i. and Crop Research Institute, v.v.i., Rozvojova 263, 162 05 Prague 6 (Czech Republic); Benesova, Dagmar [Laboratory of Plant Biotechnologies, Joint Laboratory of Institute of Experimental Botany AS CR, v.v.i. and Crop Research Institute, v.v.i., Rozvojova 263, 162 05 Prague 6 (Czech Republic); Faculty of Environment Technology, Institute of Chemical Technology, Technicka 5, 166 28 Prague 6 (Czech Republic); Dvorakova, Marcela [Laboratory of Plant Biotechnologies, Joint Laboratory of Institute of Experimental Botany AS CR, v.v.i. and Crop Research Institute, v.v.i., Rozvojova 263, 162 05 Prague 6 (Czech Republic); Vanek, Tomas, E-mail: vanek@ueb.cas.cz [Laboratory of Plant Biotechnologies, Joint Laboratory of Institute of Experimental Botany AS CR, v.v.i. and Crop Research Institute, v.v.i., Rozvojova 263, 162 05 Prague 6 (Czech Republic)

    2011-06-15

    Hydroponicaly cultivated plants were grown on medium containing uranium. The appropriate concentrations of uranium for the experiments were selected on the basis of a standard ecotoxicity test. The most sensitive plant species was determined to be Lactuca sativa with an EC{sub 50} value about 0.1 mM. Cucumis sativa represented the most resistant plant to uranium (EC{sub 50} = 0.71 mM). Therefore, we used the uranium in a concentration range from 0.1 to 1 mM. Twenty different plant species were tested in hydroponic solution supplemented by 0.1 mM or 0.5 mM uranium concentration. The uranium accumulation of these plants varied from 0.16 mg/g DW to 0.011 mg/g DW. The highest uranium uptake was determined for Zea mays and the lowest for Arabidopsis thaliana. The amount of accumulated uranium was strongly influenced by uranium concentration in the cultivation medium. Autoradiography showed that uranium is mainly localized in the root system of the plants tested. Additional experiments demonstrated the possibility of influencing the uranium uptake from the cultivation medium by amendments. Tartaric acid was able to increase uranium uptake by Brassica oleracea and Sinapis alba up to 2.8 times or 1.9 times, respectively. Phosphate deficiency increased uranium uptake up to 4.5 times or 3.9 times, respectively, by Brassica oleracea and S. alba. In the case of deficiency of iron or presence of cadmium ions we did not find any increase in uranium accumulation. - Highlights: > The uranium accumulation in twenty different plant species varied from 0.160 to 0.011 mg/g DW. > Uranium is mainly localized in the root system. > Tartaric acid was able to increase uranium uptake by Brassica oleracea and Sinapis alba. > The phosphates deficiency increase the uranium uptake.

  6. Uranium uptake by hydroponically cultivated crop plants.

    Science.gov (United States)

    Soudek, Petr; Petrová, Sárka; Benešová, Dagmar; Dvořáková, Marcela; Vaněk, Tomáš

    2011-06-01

    Hydroponicaly cultivated plants were grown on medium containing uranium. The appropriate concentrations of uranium for the experiments were selected on the basis of a standard ecotoxicity test. The most sensitive plant species was determined to be Lactuca sativa with an EC(50) value about 0.1mM. Cucumis sativa represented the most resistant plant to uranium (EC(50)=0.71 mM). Therefore, we used the uranium in a concentration range from 0.1 to 1mM. Twenty different plant species were tested in hydroponic solution supplemented by 0.1mM or 0.5mM uranium concentration. The uranium accumulation of these plants varied from 0.16 mg/g DW to 0.011 mg/g DW. The highest uranium uptake was determined for Zea mays and the lowest for Arabidopsis thaliana. The amount of accumulated uranium was strongly influenced by uranium concentration in the cultivation medium. Autoradiography showed that uranium is mainly localized in the root system of the plants tested. Additional experiments demonstrated the possibility of influencing the uranium uptake from the cultivation medium by amendments. Tartaric acid was able to increase uranium uptake by Brassica oleracea and Sinapis alba up to 2.8 times or 1.9 times, respectively. Phosphate deficiency increased uranium uptake up to 4.5 times or 3.9 times, respectively, by Brassica oleracea and S. alba. In the case of deficiency of iron or presence of cadmium ions we did not find any increase in uranium accumulation. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Transfer of radionuclides to crop plants through roots

    International Nuclear Information System (INIS)

    Uchida, Shigeo; Sumiya, Misako; Ohmomo, Yoichiro

    1987-01-01

    In an atmospheric discharge of radioiodines, direct deposition of the nuclides onto leaf surface must be the most significant pathway. However, root uptake is also of importance specifically for 129 I because of its long half life of 1.57 x 10 7 years. In order to estimate the amount of the nuclide transferred to the crop plants from contaminated field, the experiments were carried out using solution culture. Rice plant, Oryza sativa cv. koshihikari, spinach, Spinacea oleracea L., radish, Raphanus sativus L., and the other four kinds of crop plants were exposed to culture solution in which Na 131 I were contained. The transfer rates, defined as the ratio of activity of plant sample per day to the mean activity of culture solution, were calculated. And the differences by the organs of each crop plant and by plant species were discussed in this paper. Temporal critical crop plants for 129 I were selected. (author)

  8. Lactoferrin-derived resistance against plant pathogens in transgenic plants.

    Science.gov (United States)

    Lakshman, Dilip K; Natarajan, Savithiry; Mandal, Sudhamoy; Mitra, Amitava

    2013-12-04

    Lactoferrin (LF) is a ubiquitous cationic iron-binding milk glycoprotein that contributes to nutrition and exerts a broad-spectrum primary defense against bacteria, fungi, protozoa, and viruses in mammals. These qualities make lactoferrin protein and its antimicrobial motifs highly desirable candidates to be incorporated in plants to impart broad-based resistance against plant pathogens or to economically produce them in bulk quantities for pharmaceutical and nutritional purposes. This study introduced bovine LF (BLF) gene into tobacco ( Nicotiana tabacum var. Xanthi), Arabidopsis ( A. thaliana ) and wheat ( Triticum aestivum ) via Agrobacterium -mediated plant transformation. Transgenic plants or detached leaves exhibited high levels of resistance against the damping-off causing fungal pathogen Rhizoctonia solani and the head blight causing fungal pathogen Fusarium graminearum . LF also imparted resistance to tomato plants against a bacterial pathogen, Ralstonia solanacearum . Similarly, other researchers demonstrated expression of LF and LF-mediated high-quality resistance to several other aggressive fungal and bacterial plant pathogens in transgenic plants and against viral pathogens by foliar applications of LF or its derivatives. Taken together, these studies demonstrated the effectiveness of LF for improving crop quality and its biopharming potentials for pharmaceautical and nutritional applications.

  9. Evolution of insect pest and disease resistant, high-yielding and improved quality varieties of cotton by use of ionizing radiation. Part of a coordinated programme on the use of induced mutations for disease resistance in crop plants

    International Nuclear Information System (INIS)

    Vasti, S.M.

    1981-06-01

    Disease resistant, high yielding and higher quality cotton varieties were developed. 42 interspecific hybrid progenies of earlier crosses between Gossypium barbadense and Gossypium tomentosum or Gossypium barbadense and Gossypium hirsutum were included. Out of these, 22 progenies in F 3 generation were irradiated by gamma radiation doses of 20 and 25 kR. A list is given of interspecific hybrid progenies, as are the lists of boll rot susceptible and resistant plants in the irradiated and non-irradiated populations and/or successful crosses made between 1977 and 1978

  10. RNA interference as a resistance mechanism against crop parasites in Africa: a 'Trojan horse' approach.

    Science.gov (United States)

    Runo, Steven; Alakonya, Amos; Machuka, Jesse; Sinha, Neelima

    2011-02-01

    Biological crop pests cause serious economic losses. In Africa, the most prevalent parasites are insect pests, plant pathogenic root-knot nematodes, viruses and parasitic plants. African smallholder farmers struggle to overcome these parasitic constraints to agricultural production. Crop losses and the host range of these parasites have continued to increase in spite of the use of widely advocated control methods. A sustainable method to overcome biological pests in Africa would be to develop crop germplasm resistant to parasites. This is achievable using either genetic modification (GM) or a non-GM approach. However, there is a paucity of resistant genes available for introduction. Additionally, the biological processes underpinning host parasite resistance are not sufficiently well understood. The authors review a technology platform for using RNA-mediated interference (RNAi) as bioengineered resistance to important crop parasites in Africa. To achieve acquired resistance, a host crop is stably transformed with a transgene that encodes a hairpin RNA targeting essential parasitic genes. The RNAi sequence is chosen in such a way that it shares no homology with the host's genes, so it remains 'inactive' until parasitism. Upon parasitism, the RNAi sequence enters the parasite and post-transcriptional gene silencing (PTGS) mechanisms are activated, leading to the death of the parasite. Copyright © 2010 Society of Chemical Industry.

  11. Dehydration survival of crop plants and its measurement.

    Science.gov (United States)

    Blum, Abraham; Tuberosa, Roberto

    2018-01-08

    Dehydration survival under drought stress is defined in this review as the transition from plant activity into a quiescent state of life preservation, which will be terminated by either recovery or death, depending on the stress regime and the plant's resilience. Dehydration survival is a popular phenotype by which functional genomics attempts to test gene function in drought resistance and survival. The available reports on phenotyping and genotyping of dehydration survival in genomic studies indicate that the measurement of this trait is often biased to the extent that misguided interpretations are likely to occur. This review briefly discusses the physiological basis of dehydration survival in resurrection plants and crop plants, and concludes that in phenotyping dehydration survival there is a need to distinguish between dehydration avoidance and dehydration tolerance (also termed desiccation tolerance) in affecting survival and recovery. Without this distinction, functional genomics studies of the trait might be biased. Survival due to dehydration avoidance is expressed by the capacity to maintain a relatively high plant water status as the plant is desiccated. Survival due to dehydration tolerance is expressed by delayed mortality (mortality at a relatively low plant water status) as affected by the resilience of plant metabolism. The common test of dehydration survival, using the relative recovery after a given number of stress days, is therefore insufficient because it is mainly driven by dehydration avoidance and so ignores a possible role for dehydration tolerance. Conceivable methods for more accurate phenotyping of the two components of dehydration survival are proposed and discussed. © The Author(s) 2018. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  12. Advances in induced resistance by natural compounds: towards new options for woody crop protection

    Directory of Open Access Journals (Sweden)

    Eugenio Llorens

    Full Text Available ABSTRACT: The activation of defensive responses of plants is a promising tool for controlling pests in conventional agriculture. Over the last few years, several compounds have been studied to protect crops from pests, without displaying direct toxicity for pathogenic organisms. These compounds have the ability to induce a priming state on the plants that results in resistance (or tolerance against subsequent infection by a pathogen. In terms of molecular response, induced plant defense involves a broad number of physical and biochemical changes such as callose deposition or phenolic compounds, activation of salicylic and/or jasmonic acid pathways or synthesis of defense-related enzymes. Despite the large number of studies performed to ascertain the physiological and biochemical basis of induced resistance, only a few resistance-activating compounds have been studied as a real alternative to classic means of control and the studies geared towards incorporating induced resistance into disease management programs are relatively rare. The incorporation of natural resistance inducer in pest management programs of woody crops, alone or in combination with classical methods, could be a reliable method for reducing the amount of chemical residues in the environment. In this review, we discuss the current knowledge of induced resistance in woody crops, focusing on the mode of action of compounds authorized for conventional agriculture. We conclude by discussing the environmental and economic advantages of applying resistance inducers to conventional agriculture with special emphasis on natural compounds.

  13. Ethical reflections on herbicide resistant crops

    DEFF Research Database (Denmark)

    Madsen, Kathrine Hauge; Sandøe, Peter

    2005-01-01

    are perceived asrisky because they seem to share certain features: in particular, their long-term effects are unknown andthey are dreaded. Other value questions also come into play. The public seems to be concerned that risksare not outweighed by usefulness, that using HR crops is the wrong path to sustainable...

  14. [Research of the Bt crop biomass dynamics upon the invasion of Bt-resistant pests. A mathematical model].

    Science.gov (United States)

    Rusakov, A V; Medvinskiĭ, A B; Li, B -L; Gonik, M M

    2009-01-01

    The results of simulations of some consequences of the invasion of Bt-resistant pests into an agricultural ecosystem containing a Bt crop are presented. It is shown that the invasion of Bt-resistant pests leads to changes in the plant biomass dynamics, a decrease in the Bt crop production, and the deterioration of the predictability of the Bt crop production. We show that the parameter values at which the badly predictable Bt crop production takes place, occupy a minor area in the model parameter space. The size of the area depends on the insect reproduction period and the duration of the growing season.

  15. Return to Resistance: Breeding Crops to Reduce Pesticide ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Traditional plant breeding techniques have led us to depend more and more on chemical pesticides to protect ourcrops. Return to Resistance shows gardeners, farmers, and plant breeders how to use a long-neglected technique to create hardy new plant varieties that are naturally resistant to pests and disease. Horizontal ...

  16. Large SNP arrays for genotyping in crop plants

    Indian Academy of Sciences (India)

    2012-10-15

    Oct 15, 2012 ... within approximately 10 years, whole genome sequencing of many lines will be the ultimate method of choice for a comprehensive genotyping effort. Table 1. Overview on large genotyping array development in major crop plants. Crop species. Array size*. Reference. Apple (Malus domestica). 8 K. Chagné ...

  17. Managing Phenol Contents in Crop Plants by Phytochemical Farming and Breeding—Visions and Constraints

    Directory of Open Access Journals (Sweden)

    Dieter Treutter

    2010-03-01

    Full Text Available Two main fields of interest form the background of actual demand for optimized levels of phenolic compounds in crop plants. These are human health and plant resistance to pathogens and to biotic and abiotic stress factors. A survey of agricultural technologies influencing the biosynthesis and accumulation of phenolic compounds in crop plants is presented, including observations on the effects of light, temperature, mineral nutrition, water management, grafting, elevated atmospheric CO2, growth and differentiation of the plant and application of elicitors, stimulating agents and plant activators. The underlying mechanisms are discussed with respect to carbohydrate availability, trade-offs to competing demands as well as to regulatory elements. Outlines are given for genetic engineering and plant breeding. Constraints and possible physiological feedbacks are considered for successful and sustainable application of agricultural techniques with respect to management of plant phenol profiles and concentrations.

  18. Recessive Resistance to Plant Viruses: Potential Resistance Genes Beyond Translation Initiation Factors

    Directory of Open Access Journals (Sweden)

    Masayoshi Hashimoto

    2016-10-01

    Full Text Available The ability of plant viruses to propagate their genomes in host cells depends on many host factors. In the absence of an agrochemical that specifically targets plant viral infection cycles, one of the most effective methods for controlling viral diseases in plants is taking advantage of the host plant’s resistance machinery. Recessive resistance is conferred by a recessive gene mutation that encodes a host factor critical for viral infection. It is a branch of the resistance machinery and, as an inherited characteristic, is very durable. Moreover, recessive resistance may be acquired by a deficiency in a negative regulator of plant defense responses, possibly due to the autoactivation of defense signaling. Eukaryotic translation initiation factor (eIF 4E and eIF4G and their isoforms are the most widely exploited recessive resistance genes in several crop species, and they are effective against a subset of viral species. However, the establishment of efficient, recessive resistance-type antiviral control strategies against a wider range of plant viral diseases requires genetic resources other than eIF4Es. In this review, we focus on recent advances related to antiviral recessive resistance genes evaluated in model plants and several crop species. We also address the roles of next-generation sequencing and genome editing technologies in improving plant genetic resources for recessive resistance-based antiviral breeding in various crop species.

  19. Herbicide-Resistant Crops: Utilities and Limitations for Herbicide-Resistant Weed Management

    OpenAIRE

    Green, Jerry M.; Owen, Micheal D. K.

    2010-01-01

    Since 1996, genetically modified herbicide-resistant (HR) crops, particularly glyphosate-resistant (GR) crops, have transformed the tactics that corn, soybean, and cotton growers use to manage weeds. The use of GR crops continues to grow, but weeds are adapting to the common practice of using only glyphosate to control weeds. Growers using only a single mode of action to manage weeds need to change to a more diverse array of herbicidal, mechanical, and cultural practices to maintain the effec...

  20. Energy crops for biogas plants. Thuringia; Energiepflanzen fuer Biogasanlagen. Thueringen

    Energy Technology Data Exchange (ETDEWEB)

    Biertuempfel, A.; Bischof, R.; Conrad, M. (and others)

    2012-06-15

    In the brochure under consideration the Agency for Renewable Resources (Guelzow-Pruezen, Federal Republic of Germany) reports on the support of the implementation of different plant cultures in structure of plantations and crop rotation systems of companies under consideration of the Federal State Thuringia. The main chapters of this brochure are: Crops for the production of biogas; implementation in plantations; ensilage and biogas yields; economy of the cultivation of energy plants.

  1. Energy crops for biogas plants. Saxony; Energiepflanzen fuer Biogasanlagen. Sachsen

    Energy Technology Data Exchange (ETDEWEB)

    Biertuempfel, A.; Buttlar, C. von; Conrad, M. [and others

    2012-08-15

    In the brochure under consideration the Agency for Renewable Resources (Guelzow-Pruezen, Federal Republic of Germany) reports on the support of the implementation of different plant cultures in structure of plantations and crop rotation systems of companies under consideration of the Federal State Saxony. The main chapters of this brochure are: Crops for the production of biogas; implementation in plantations; ensilage and biogas yields; economy of the cultivation of energy plants.

  2. Transfer of radionuclides to crop plants through roots

    International Nuclear Information System (INIS)

    Uchida, Shigeo; Sumiya, Misako; Ohmomo, Yoichiro

    1987-01-01

    In assessing the internal radiation dose to man from radionuclides released from nuclear facilities including ground disposal facilities, the soil-crop plants-man pathway is one of the important ones. The information on this pathway, however, is quite limited in Japan. This paper focuses on transfer of 54 Mn, 65 Zn and 60 Co from culture solution to crop plants, particularly to the edible parts of the plants. Rice plant (Oryza sativa cv. Koshihikari), spinach (Spinacea oleracea L.), soybean (Glycine max Merr.), and the other four kinds of crop plants were transplanted to culture solution in which 54 MnCl 2 , 65 ZnCl 2 or 60 CoCl 2 were contained, and their transfer rates in each organ of the plants were obtained. The differences in the distribution patterns among the crop plant species, among the nuclides and the effect of the stable isotope concentration in the solution on their distributions were discussed in this paper. And critical crop plants for 54 Mn, 65 Zn and 60 Co were also selected. (author)

  3. Controversy Associated With the Common Component of Most Transgenic Plants – Kanamycin Resistance Marker Gene

    OpenAIRE

    Jelenić, Srećko

    2003-01-01

    Plant genetic engineering is a powerful tool for producing crops resistant to pests, diseases and abiotic stress or crops with improved nutritional value or better quality products. Currently over 70 genetically modified (GM) crops have been approved for use in different countries. These cover a wide range of plant species with significant number of different modified traits. However, beside the technology used for their improvement, the common component of most GM crops is the neomycin phosp...

  4. Enhancing (crop) plant photosynthesis by introducing novel genetic diversity.

    Science.gov (United States)

    Dann, Marcel; Leister, Dario

    2017-09-26

    Although some elements of the photosynthetic light reactions might appear to be ideal, the overall efficiency of light conversion to biomass has not been optimized during evolution. Because crop plants are depleted of genetic diversity for photosynthesis, efforts to enhance its efficiency with respect to light conversion to yield must generate new variation. In principle, three sources of natural variation are available: (i) rare diversity within extant higher plant species, (ii) photosynthetic variants from algae, and (iii) reconstruction of no longer extant types of plant photosynthesis. Here, we argue for a novel approach that outsources crop photosynthesis to a cyanobacterium that is amenable to adaptive evolution. This system offers numerous advantages, including a short generation time, virtually unlimited population sizes and high mutation rates, together with a versatile toolbox for genetic manipulation. On such a synthetic bacterial platform, 10 000 years of (crop) plant evolution can be recapitulated within weeks. Limitations of this system arise from its unicellular nature, which cannot reproduce all aspects of crop photosynthesis. But successful establishment of such a bacterial host for crop photosynthesis promises not only to enhance the performance of eukaryotic photosynthesis but will also reveal novel facets of the molecular basis of photosynthetic flexibility.This article is part of the themed issue 'Enhancing photosynthesis in crop plants: targets for improvement'. © 2017 The Author(s).

  5. Do Refuge Plants Favour Natural Pest Control in Maize Crops?

    Science.gov (United States)

    Quispe, Reinaldo; Mazón, Marina; Rodríguez-Berrío, Alexander

    2017-01-01

    The use of non-crop plants to provide the resources that herbivorous crop pests’ natural enemies need is being increasingly incorporated into integrated pest management programs. We evaluated insect functional groups found on three refuges consisting of five different plant species each, planted next to a maize crop in Lima, Peru, to investigate which refuge favoured natural control of herbivores considered as pests of maize in Peru, and which refuge plant traits were more attractive to those desirable enemies. Insects occurring in all the plants, including the maize crop itself, were sampled weekly during the crop growing cycle, from February to June 2011. All individuals collected were identified and classified into three functional groups: herbivores, parasitoids, and predators. Refuges were compared based on their effectiveness in enhancing the populations of predator and parasitoid insects of the crop enemies. Refuges A and B were the most effective, showing the highest richness and abundance of both predators and parasitoids, including several insect species that are reported to attack the main insect pests of maize (Spodoptera frugiperda and Rhopalosiphum maidis), as well as other species that serve as alternative hosts of these natural enemies. PMID:28718835

  6. Do Refuge Plants Favour Natural Pest Control in Maize Crops?

    Science.gov (United States)

    Quispe, Reinaldo; Mazón, Marina; Rodríguez-Berrío, Alexander

    2017-07-18

    The use of non-crop plants to provide the resources that herbivorous crop pests' natural enemies need is being increasingly incorporated into integrated pest management programs. We evaluated insect functional groups found on three refuges consisting of five different plant species each, planted next to a maize crop in Lima, Peru, to investigate which refuge favoured natural control of herbivores considered as pests of maize in Peru, and which refuge plant traits were more attractive to those desirable enemies. Insects occurring in all the plants, including the maize crop itself, were sampled weekly during the crop growing cycle, from February to June 2011. All individuals collected were identified and classified into three functional groups: herbivores, parasitoids, and predators. Refuges were compared based on their effectiveness in enhancing the populations of predator and parasitoid insects of the crop enemies. Refuges A and B were the most effective, showing the highest richness and abundance of both predators and parasitoids, including several insect species that are reported to attack the main insect pests of maize ( Spodoptera frugiperda and Rhopalosiphum maidis ), as well as other species that serve as alternative hosts of these natural enemies.

  7. Comparison of herbicide regimes and the associated potential enviromental effects of glyphosate-resistant crops versus what they replace in Europe

    NARCIS (Netherlands)

    Kleter, G.A.; Harris, C.; Stephenson, G.R.; Unsworth, J.

    2008-01-01

    While cultivation of transgenic crops takes place in seven of the EU member states, this constitutes a relatively limited part of the total acreage planted to these crops worldwide. The only glyphosate-resistant (GR) crop grown commercially until recently has been soybean in Romania. In addition,

  8. Crop and medicinal plants proteomics in response to salt stress

    Directory of Open Access Journals (Sweden)

    Keyvan eAghaei

    2013-01-01

    Full Text Available Increasing of world population marks a serious need to create new crop cultivars and medicinal plants with high growth and production at any environmental situations. Among the environmental unfavorable conditions, salinity is the most widespread in the world. Crop production and growth severely decreases under salt stress; however, some crop cultivars show significant tolerance against the negative effects of salinity. Among salt stress responses of crops, proteomic responses play a pivotal role in their ability to cope with it and have become the main center of notification. Many physiological responses are detectable in terms of protein increase and decrease even before physiological responses take place. Thus proteomic approach makes a short cut in the way of inferring how crops response to salt stress. Nowadays many salt-responsive proteins such as heat shock proteins, pathogen related proteins, protein kinases, ascorbate peroxidase, osmotin, ornithine decarboxylase and some transcription factors, have been detected in some major crops which are thought to give them the ability of withstanding against salt stress. Proteomic analysis of medicinal plants also revealed that alkaloid biosynthesis related proteins such as tryptophan synthase, codeinone reductase, strictosidine synthase and 12-oxophytodienoate reductase might have major role in production of secondary metabolites. In this review we are comparing some different or similar proteomic responses of several crops and medicinal plants to salt stress and discuss about the future prospects.

  9. Plant pathogen resistance

    Science.gov (United States)

    Greenberg, Jean T; Jung, Ho Won; Tschaplinski, Timothy

    2012-11-27

    Azelaic acid or its derivatives or analogs induce a robust and a speedier defense response against pathogens in plants. Azelaic acid treatment alone does not induce many of the known defense-related genes but activates a plant's defense signaling upon pathogen exposure.

  10. Engineered gray mold resistance, antioxidant capacity, and pigmentation in betalain-producing crops and ornamentals.

    Science.gov (United States)

    Polturak, Guy; Grossman, Noam; Vela-Corcia, David; Dong, Yonghui; Nudel, Adi; Pliner, Margarita; Levy, Maggie; Rogachev, Ilana; Aharoni, Asaph

    2017-08-22

    Betalains are tyrosine-derived red-violet and yellow plant pigments known for their antioxidant activity, health-promoting properties, and wide use as food colorants and dietary supplements. By coexpressing three genes of the recently elucidated betalain biosynthetic pathway, we demonstrate the heterologous production of these pigments in a variety of plants, including three major food crops: tomato, potato, and eggplant, and the economically important ornamental petunia. Combinatorial expression of betalain-related genes also allowed the engineering of tobacco plants and cell cultures to produce a palette of unique colors. Furthermore, betalain-producing tobacco plants exhibited significantly increased resistance toward gray mold ( Botrytis cinerea ), a pathogen responsible for major losses in agricultural produce. Heterologous production of betalains is thus anticipated to enable biofortification of essential foods, development of new ornamental varieties, and innovative sources for commercial betalain production, as well as utilization of these pigments in crop protection.

  11. Endophytic fungi: resource for gibberellins and crop abiotic stress resistance.

    Science.gov (United States)

    Khan, Abdul Latif; Hussain, Javid; Al-Harrasi, Ahmed; Al-Rawahi, Ahmed; Lee, In-Jung

    2015-03-01

    The beneficial effects of endophytes on plant growth are important for agricultural ecosystems because they reduce the need for fertilizers and decrease soil and water pollution while compensating for environmental perturbations. Endophytic fungi are a novel source of bioactive secondary metabolites; moreover, recently they have been found to produce physiologically active gibberellins as well. The symbiosis of gibberellins producing endophytic fungi with crops can be a promising strategy to overcome the adverse effects of abiotic stresses. The association of such endophytes has not only increased plant biomass but also ameliorated plant-growth during extreme environmental conditions. Endophytic fungi represent a trove of unexplored biodiversity and a frequently overlooked component of crop ecology. The present review describes the role of gibberellins producing endophytic fungi, suggests putative mechanisms involved in plant endophyte stress interactions and discusses future prospects in this field.

  12. Modification of flavonoid biosynthesis in crop plants

    NARCIS (Netherlands)

    Schijlen, E.G.W.M.; Vos, de C.H.; Tunen, van A.J.; Bovy, A.G.

    2004-01-01

    Flavonoids comprise the most common group of polyphenolic plant secondary metabolites. In plants, flavonoids play an important role in biological processes. Beside their function as pigments in flowers and fruits, to attract pollinators and seed dispersers, flavonoids are involved in UV-scavenging,

  13. Plant factories; crop transpiration and energy balance

    NARCIS (Netherlands)

    Graamans, Luuk; Dobbelsteen, van den Andy; Meinen, Esther; Stanghellini, Cecilia

    2017-01-01

    Population growth and rapid urbanisation may result in a shortage of food supplies for cities in the foreseeable future. Research on closed plant production systems, such as plant factories, has attempted to offer perspectives for robust (urban) agricultural systems. Insight into the explicit role

  14. Spatio-Temporal Variation in Landscape Composition May Speed Resistance Evolution of Pests to Bt Crops.

    Directory of Open Access Journals (Sweden)

    Anthony R Ives

    Full Text Available Transgenic crops that express insecticide genes from Bacillus thuringiensis (Bt are used worldwide against moth and beetle pests. Because these engineered plants can kill over 95% of susceptible larvae, they can rapidly select for resistance. Here, we use a model for a pyramid two-toxin Bt crop to explore the consequences of spatio-temporal variation in the area of Bt crop and non-Bt refuge habitat. We show that variability over time in the proportion of suitable non-Bt breeding habitat, Q, or in the total area of Bt and suitable non-Bt habitat, K, can increase the overall rate of resistance evolution by causing short-term surges of intense selection. These surges can be exacerbated when temporal variation in Q and/or K cause high larval densities in refuges that increase density-dependent mortality; this will give resistant larvae in Bt fields a relative advantage over susceptible larvae that largely depend on refuges. We address the effects of spatio-temporal variation in a management setting for two bollworm pests of cotton, Helicoverpa armigera and H. punctigera, and field data on landscape crop distributions from Australia. Even a small proportion of Bt fields available to egg-laying females when refuges are sparse may result in high exposure to Bt for just a single generation per year and cause a surge in selection. Therefore, rapid resistance evolution can occur when Bt crops are rare rather than common in the landscape. These results highlight the need to understand spatio-temporal fluctuations in the landscape composition of Bt crops and non-Bt habitats in order to design effective resistance management strategies.

  15. Targeted modification of plant genomes for precision crop breeding.

    Science.gov (United States)

    Hilscher, Julia; Bürstmayr, Hermann; Stoger, Eva

    2017-01-01

    The development of gene targeting and gene editing techniques based on programmable site-directed nucleases (SDNs) has increased the precision of genome modification and made the outcomes more predictable and controllable. These approaches have achieved rapid advances in plant biotechnology, particularly the development of improved crop varieties. Here, we review the range of alterations which have already been implemented in plant genomes, and summarize the reported efficiencies of precise genome modification. Many crop varieties are being developed using SDN technologies and although their regulatory status in the USA is clear there is still a decision pending in the EU. DNA-free genome editing strategies are briefly discussed because they also present a unique regulatory challenge. The potential applications of genome editing in plant breeding and crop improvement are highlighted by drawing examples from the recent literature. Copyright © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Non-GMO genetically edited crop plants.

    Science.gov (United States)

    Kanchiswamy, Chidananda Nagamangala; Malnoy, Mickael; Velasco, Riccardo; Kim, Jin-Soo; Viola, Roberto

    2015-09-01

    Direct delivery of purified Cas9 protein with guide RNA into plant cells, as opposed to plasmid-mediated delivery, displays high efficiency and reduced off-target effects. Following regeneration from edited cells, the ensuing plant is also likely to bypass genetically modified organism (GMO) legislation as the genome editing complex is degraded in the recipient cells. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. The Lr34 adult plant rust resistance gene provides seedling resistance in durum wheat without senescence

    OpenAIRE

    Rinaldo, Amy; Gilbert, Brian; Boni, Rainer; Krattinger, Simon G.; Singh, Davinder; Park, Robert F.; Lagudah, Evans; Ayliffe, Michael

    2017-01-01

    Summary The hexaploid wheat (Triticum aestivum) adult plant resistance gene, Lr34/Yr18/Sr57/Pm38/Ltn1, provides broad?spectrum resistance to wheat leaf rust (Lr34), stripe rust (Yr18), stem rust (Sr57) and powdery mildew (Pm38) pathogens, and has remained effective in wheat crops for many decades. The partial resistance provided by this gene is only apparent in adult plants and not effective in field?grown seedlings. Lr34 also causes leaf tip necrosis (Ltn1) in mature adult plant leaves when ...

  18. Volatile Semiochemical Mediated Plant Defense in Cereals: A Novel Strategy for Crop Protection

    Directory of Open Access Journals (Sweden)

    Amanuel Tamiru

    2017-09-01

    Full Text Available Plants have evolved highly intriguing ways of defending themselves against insect attacks, including through emission of defense volatiles. These volatiles serve the plant’s defense by directly repelling phytophagous insects and/or indirectly through attracting natural enemies antagonistic to the herbivores. Several laboratory studies established the potential of improving plant resistance against insect attacks by manipulating the plant-derived volatile semiochemicals emissions. Yet, more efforts need to be conducted to translate the promising laboratory studies to fight economically-important crop pests under real field conditions. This is needed to address an increasing demand for alternative pest control options driven by ecological and environmental costs associated with the use of broad-spectrum insecticides. The practical examples discussed in this review paper demonstrate the real prospect of exploiting an inducible and constitutive plant volatile semiochemicals for developing novel and ecologically-sustainable pest management strategies to protect cereal crops from damaging insect pests.

  19. Herbicide-resistant crops: utilities and limitations for herbicide-resistant weed management.

    Science.gov (United States)

    Green, Jerry M; Owen, Micheal D K

    2011-06-08

    Since 1996, genetically modified herbicide-resistant (HR) crops, particularly glyphosate-resistant (GR) crops, have transformed the tactics that corn, soybean, and cotton growers use to manage weeds. The use of GR crops continues to grow, but weeds are adapting to the common practice of using only glyphosate to control weeds. Growers using only a single mode of action to manage weeds need to change to a more diverse array of herbicidal, mechanical, and cultural practices to maintain the effectiveness of glyphosate. Unfortunately, the introduction of GR crops and the high initial efficacy of glyphosate often lead to a decline in the use of other herbicide options and less investment by industry to discover new herbicide active ingredients. With some exceptions, most growers can still manage their weed problems with currently available selective and HR crop-enabled herbicides. However, current crop management systems are in jeopardy given the pace at which weed populations are evolving glyphosate resistance. New HR crop technologies will expand the utility of currently available herbicides and enable new interim solutions for growers to manage HR weeds, but will not replace the long-term need to diversify weed management tactics and discover herbicides with new modes of action. This paper reviews the strengths and weaknesses of anticipated weed management options and the best management practices that growers need to implement in HR crops to maximize the long-term benefits of current technologies and reduce weed shifts to difficult-to-control and HR weeds.

  20. Plant breeding: Induced mutation technology for crop improvement

    International Nuclear Information System (INIS)

    Novak, F.J.; Brunner, H.

    1992-01-01

    Plant breeding requires genetic variation of useful traits for crop improvement, but the desired variation is often lacking. Mutagenic agents, such as radiation and certain chemicals, can be used to induce mutations and generate genetic variations from which desirable mutants may be selected. After a brief summary of the methods currently employed in plant breeding, especially those inducing genetic engineering, this article describes the activities of the Plant Breeding Unit of the IAEA Laboratories at Seibersdorf, summarizing the research and development areas currently being pursued. The banana plant is chosen to exemplify the Laboratories' research

  1. Folates in plants: research advances and progress in crop biofortification

    Science.gov (United States)

    Gorelova, Vera; Ambach, Lars; Rébeillé, Fabrice; Stove, Christophe; Van Der Straeten, Dominique

    2017-03-01

    Folates, also known as B9 vitamins, serve as donors and acceptors in one-carbon (C1) transfer reactions. The latter are involved in synthesis of many important biomolecules, such as amino acids, nucleic acids and vitamin B5. Folates also play a central role in the methyl cycle that provides one-carbon groups for methylation reactions. The important functions fulfilled by folates make them essential in all living organisms. Plants, being able to synthesize folates de novo, serve as an excellent dietary source of folates for animals that lack the respective biosynthetic pathway. Unfortunately, the most important staple crops such as rice, potato and maize are rather poor sources of folates. Insufficient folate consumption is known to cause severe developmental disorders in humans. Two approaches are employed to fight folate deficiency: pharmacological supplementation in the form of folate pills and biofortification of staple crops. As the former approach is considered rather costly for the major part of the world population, biofortification of staple crops is viewed as a decent alternative in the struggle against folate deficiency. Therefore strategies, challenges and recent progress of folate enhancement in plants will be addressed in this review. Apart from the ever-growing need for the enhancement of nutritional quality of crops, the world population faces climate change catastrophes or environmental stresses, such as elevated temperatures, drought, salinity that severely affect growth and productivity of crops. Due to immense diversity of their biochemical functions, folates take part in virtually every aspect of plant physiology. Any disturbance to the plant folate metabolism leads to severe growth inhibition and, as a consequence, to a lower productivity. Whereas today’s knowledge of folate biochemistry can be considered very profound, evidence on the physiological roles of folates in plants only starts to emerge. In the current review we will discuss the

  2. Using genetically modified tomato crop plants with purple leaves for absolute weed/crop classification.

    Science.gov (United States)

    Lati, Ran N; Filin, Sagi; Aly, Radi; Lande, Tal; Levin, Ilan; Eizenberg, Hanan

    2014-07-01

    Weed/crop classification is considered the main problem in developing precise weed-management methodologies, because both crops and weeds share similar hues. Great effort has been invested in the development of classification models, most based on expensive sensors and complicated algorithms. However, satisfactory results are not consistently obtained due to imaging conditions in the field. We report on an innovative approach that combines advances in genetic engineering and robust image-processing methods to detect weeds and distinguish them from crop plants by manipulating the crop's leaf color. We demonstrate this on genetically modified tomato (germplasm AN-113) which expresses a purple leaf color. An autonomous weed/crop classification is performed using an invariant-hue transformation that is applied to images acquired by a standard consumer camera (visible wavelength) and handles variations in illumination intensities. The integration of these methodologies is simple and effective, and classification results were accurate and stable under a wide range of imaging conditions. Using this approach, we simplify the most complicated stage in image-based weed/crop classification models. © 2013 Society of Chemical Industry.

  3. Risk assessment of genetically engineered crops: fitness effects of virus-resistance transgenes in wild Cucurbita pepo.

    Science.gov (United States)

    Laughlin, Karen D; Power, Alison G; Snow, Allison A; Spencer, Lawrence J

    2009-07-01

    The development of crops genetically engineered for pathogen resistance has raised concerns that crop-to-wild gene flow could release wild or weedy relatives from regulation by the pathogens targeted by the transgenes that confer resistance. Investigation of these risks has also raised questions about the impact of gene flow from conventional crops into wild plant populations. Viruses in natural plant populations can play important roles in plant fecundity and competitive interactions. Here, we show that virus-resistance transgenes and conventional crop genes can increase fecundity of wild plants under virus pressure. We asked how gene flow from a cultivated squash (Cucurbita pepo) engineered for virus resistance would affect the fecundity of wild squash (C. pepo) in the presence and absence of virus pressure. A transgenic squash cultivar was crossed and backcrossed with wild C. pepo from Arkansas. Wild C. pepo, transgenic backcross plants, and non-transgenic backcross plants were compared in field plots in Ithaca, New York, USA. The second and third generations of backcrosses (BC2 and BC3) were used in 2002 and 2003, respectively. One-half of the plants were inoculated with zucchini yellow mosaic virus (ZYMV), and one-half of the plants were maintained as healthy controls. Virus pressure dramatically decreased the fecundity of wild C. pepo plants and non-transgenic backcross plants relative to transgenic backcross plants, which showed continued functioning of the virus-resistance transgene. In 2002, non-transgenic backcross fecundity was slightly higher than wild C. pepo fecundity under virus pressure, indicating a possible benefit of conventional crop alleles, but they did not differ in 2003 when fecundity was lower in both groups. We detected no fitness costs of the transgene in the absence of the virus. If viruses play a role in the population dynamics of wild C. pepo, we predict that gene flow from transgenic, virus-resistant squash and, to a much lesser

  4. Climate change effects on plant growth, crop yield and livestock

    NARCIS (Netherlands)

    Rötter, R.P.; Geijn, van de S.C.

    1999-01-01

    A review is given of the state of knowledge in the field of assessing climate change impacts on agricultural crops and livestock. Starting from the basic processes controlling plant growth and development, the possible impacts and interactions of climatic and other biophysical variables in different

  5. Association of non-heterocystous cyanobacteria with crop plants

    NARCIS (Netherlands)

    Ahmed, M.; Stal, L.J.; Hasnain, S.

    2010-01-01

    Cyanobacteria have the ability to form associations with organisms from all domains of life, notably with plants, which they provide with fixed nitrogen, among other substances. This study was aimed at developing artificial associations between non-heterocystous cyanobacteria and selected crop

  6. Grass plants crop water consumption model in urban parks located ...

    African Journals Online (AJOL)

    use

    2011-12-14

    Dec 14, 2011 ... Grass plants crop water consumption model in urban parks located in three different ... The result of calculations, using the climate data of July, value of the province of Antalya were. ETo=7,10464 mm/day, for Ankara .... method is recommended by Food and Agriculture. Organisation (FAO) (Allen et al., ...

  7. Natural refuge crops, buildup of resistance, and zero-refuge strategy for Bt cotton in China.

    Science.gov (United States)

    Qiao, FangBin; Huang, JiKun; Rozelle, Scott; Wilen, James

    2010-10-01

    In the context of genetically modified crops expressing the Bacillus thuringiensis (Bt) toxin, a 'refuge' refers to a crop of the same or a related species that is planted nearby to enable growth and reproduction of the target pest without the selection pressure imposed by the Bt toxin. The goal of this study is to discuss the role of natural refuge crops in slowing down the buildup of resistance of cotton bollworm (CBW), and to evaluate China's no-refuge policy for Bt cotton. We describe in detail the different factors that China should consider in relation to the refuge policy. Drawing on a review of scientific data, economic analyses of other cases, and a simulation exercise using a bio-economic model, we show that in the case of Bt cotton in China, the no-refuge policy is defensible.

  8. Glyphosate degradation in glyphosate-resistant and -susceptible crops and weeds.

    Science.gov (United States)

    Duke, Stephen O

    2011-06-08

    High levels of aminomethylphosphonic acid (AMPA), the main glyphosate metabolite, have been found in glyphosate-treated, glyphosate-resistant (GR) soybean, apparently due to plant glyphosate oxidoreductase (GOX)-like activity. AMPA is mildly phytotoxic, and under some conditions the AMPA accumulating in GR soybean correlates with glyphosate-caused phytotoxicity. A bacterial GOX is used in GR canola, and an altered bacterial glyphosate N-acetyltransferase is planned for a new generation of GR crops. In some weed species, glyphosate degradation could contribute to natural resistance. Neither an isolated plant GOX enzyme nor a gene for it has yet been reported in plants. Gene mutation or amplification of plant genes for GOX-like enzyme activity or horizontal transfer of microbial genes from glyphosate-degrading enzymes could produce GR weeds. Yet, there is no evidence that metabolic degradation plays a significant role in evolved resistance to glyphosate. This is unexpected, considering the extreme selection pressure for evolution of glyphosate resistance in weeds and the difficulty in plants of evolving glyphosate resistance via other mechanisms.

  9. Plant species evaluated for new crop potential

    Energy Technology Data Exchange (ETDEWEB)

    Carr, M.E.

    1985-01-01

    Ninety-two plant species from various regions of the USA were screened for their energy-producing potential. Samples were analysed for oil, polyphenol, hydrocarbon and protein. Oil fractions of some species were analysed for classes of lipid constituents and yields of unsaponifiable matter and fatty acids were determined. Hydrocarbon fractions of some species were analysed for rubber, gutta and waxes. Average MW and MW distribution of rubber and gutta were determined. Complete analytical data for 16 species is presented. Large quantities of oil were obtained from Philadelphus coronarius, Cacalia muhlenbergii, Lindera benzoin and Koelreuteria paniculata. High yields of polyphenols came from Acer ginnala, Cornus obliqua and Salix caprea and maximum yields of hydrocarbon and protein were from Elymus virginicus and Lindera benzoin, respectively.

  10. Radiation techniques in crop and plant breeding. Multiplying the benefits

    International Nuclear Information System (INIS)

    Ahloowalia, B.S.

    1998-01-01

    World food production is based on growing a wide variety of fruits, vegetables, and crops developed through advances in science. Plant breeders have produced multiple varieties that grow well in various types of soils and under diverse climates in different regions of the world. Conventionally, this is done by sexual hybridization. This involves transferring pollen from one parent plant to another to obtain hybrids. The subsequent generations of these hybrids are grown to select plants which combine the desired characters of the parents. However, another method exists by which the genetic make-up of a given plant variety can be changed without crossing with another variety. With this method, a variety retains all its original attributes but is upgraded in one or two changed characteristics. This method is based on radiation-induced genetic changes, and its referred to as ''induced mutations''. During the past thirty years, more than 1800 mutant varieties of plants have been released, many, of which were induced with radiation. Plant tissue and cell culture (also called in vitro culture) in combination with radiation is a powerful technique to induce mutations, particularly for the improvement of vegetatively propagated crops. These crops include cassava, garlic, potato, sweet potato, yams, sugarcane, ornamentals such as chrysanthemum, carnation, roses, tulips, daffodil, and many fruits (e.g. apple, banana, plantain, citrus, date palm, grape, papaya, passion fruit, and kiwi fruit). In some of these plants, either there is no seed set (e.g. banana) or the seed progeny produces plants which do not have the right combination of the desired characteristics. These techniques are also useful in the improvement of forest trees having a long lifespan before they produce fruit and seed. This article briefly reviews advances in plant breeding techniques, with a view towards improving the transfer of technologies to more countries

  11. Companion cropping with potato onion enhances the disease resistance of tomato against Verticillium dahliae

    Directory of Open Access Journals (Sweden)

    Xuepeng eFu

    2015-09-01

    Full Text Available Intercropping could alleviate soil-borne diseases, however, few studies focused on the immunity of the host plant induced by the interspecific interactions. To test whether or not intercropping could enhance the disease resistance of host plant, we investigated the effect of companion cropping with potato onion on tomato Verticillium wilt caused by Verticillium dahliae (V. dahliae. To investigate the mechanisms, the root exudates were collected from tomato and potato onion which were grown together or separately, and were used to examine the antifungal activities against V. dahliae in vitro, respectively. Furthermore, RNA-seq was used to examine the expression pattern of genes related to disease resistance in tomato companied with potato onion compared to that in tomato grown alone, under the condition of infection with V. dahliae. The results showed that companion cropping with potato onion could alleviate the incidence and severity of tomato Verticillium wilt. The further studies revealed that the root exudates from tomato companied with potato onion significantly inhibited the mycelia growth and spore germination of V. dahliae. However, there were no significant effects on these two measurements for the root exudates from potato onion grown alone or from potato onion grown with tomato. RNA-seq data analysis showed the disease defense genes associated with pathogenesis-related proteins, biosynthesis of lignin, hormone metabolism and signal transduction were expressed much higher in the tomato companied with potato onion than those in the tomato grown alone, which indicated that these defense genes play important roles in tomato against V. dahliae infection, and meant that the disease resistance of tomato against V. dahliae was enhanced in the companion copping with potato onion. We proposed that companion cropping with potato onion could enhance the disease resistance of tomato against V. dahliae by regulating the expression of genes related

  12. Quantifying the effect of crop spatial arrangement on weed suppression using functional-structural plant modelling

    NARCIS (Netherlands)

    Evers, Jochem B.; Bastiaans, Lammert

    2016-01-01

    Suppression of weed growth in a crop canopy can be enhanced by improving crop competitiveness. One way to achieve this is by modifying the crop planting pattern. In this study, we addressed the question to what extent a uniform planting pattern increases the ability of a crop to compete with weed

  13. Reevaluating the conceptual framework for applied research on host-plant resistance.

    Science.gov (United States)

    Stout, Michael J

    2013-06-01

    Applied research on host-plant resistance to arthropod pests has been guided over the past 60 years by a framework originally developed by Reginald Painter in his 1951 book, Insect Resistance in Crop Plants. Painter divided the "phenomena" of resistance into three "mechanisms," nonpreference (later renamed antixenosis), antibiosis, and tolerance. The weaknesses of this framework are discussed. In particular, this trichotomous framework does not encompass all known mechanisms of resistance, and the antixenosis and antibiosis categories are ambiguous and inseparable in practice. These features have perhaps led to a simplistic approach to understanding arthropod resistance in crop plants. A dichotomous scheme is proposed as a replacement, with a major division between resistance (plant traits that limit injury to the plant) and tolerance (plant traits that reduce amount of yield loss per unit injury), and the resistance category subdivided into constitutive/inducible and direct/indirect subcategories. The most important benefits of adopting this dichotomous scheme are to more closely align the basic and applied literatures on plant resistance and to encourage a more mechanistic approach to studying plant resistance in crop plants. A more mechanistic approach will be needed to develop novel approaches for integrating plant resistance into pest management programs. © 2012 Institute of Zoology, Chinese Academy of Sciences.

  14. Quantifying the effect of crop spatial arrangement on weed suppression using functional-structural plant modelling.

    Science.gov (United States)

    Evers, Jochem B; Bastiaans, Lammert

    2016-05-01

    Suppression of weed growth in a crop canopy can be enhanced by improving crop competitiveness. One way to achieve this is by modifying the crop planting pattern. In this study, we addressed the question to what extent a uniform planting pattern increases the ability of a crop to compete with weed plants for light compared to a random and a row planting pattern, and how this ability relates to crop and weed plant density as well as the relative time of emergence of the weed. To this end, we adopted the functional-structural plant modelling approach which allowed us to explicitly include the 3D spatial configuration of the crop-weed canopy and to simulate intra- and interspecific competition between individual plants for light. Based on results of simulated leaf area development, canopy photosynthesis and biomass growth of the crop, we conclude that differences between planting pattern were small, particularly if compared to the effects of relative time of emergence of the weed, weed density and crop density. Nevertheless, analysis of simulated weed biomass demonstrated that a uniform planting of the crop improved the weed-suppression ability of the crop canopy. Differences in weed suppressiveness between planting patterns were largest with weed emergence before crop emergence, when the suppressive effect of the crop was only marginal. With simultaneous emergence a uniform planting pattern was 8 and 15 % more competitive than a row and a random planting pattern, respectively. When weed emergence occurred after crop emergence, differences between crop planting patterns further decreased as crop canopy closure was reached early on regardless of planting pattern. We furthermore conclude that our modelling approach provides promising avenues to further explore crop-weed interactions and aid in the design of crop management strategies that aim at improving crop competitiveness with weeds.

  15. Low crop plant population densities promote pollen-mediated gene flow in spring wheat (Triticum aestivum L.).

    Science.gov (United States)

    Willenborg, Christian J; Brûlé-Babel, Anita L; Van Acker, Rene C

    2009-12-01

    Transgenic wheat is currently being field tested with the intent of eventual commercialization. The development of wheat genotypes with novel traits has raised concerns regarding the presence of volunteer wheat populations and the role they may play in facilitating transgene movement. Here, we report the results of a field experiment that investigated the potential of spring wheat plant population density and crop height to minimize gene flow from a herbicide-resistant (HR) volunteer population to a non-HR crop. Pollen-mediated gene flow (PMGF) between the HR volunteer wheat population and four conventional spring wheat genotypes varying in height was assessed over a range of plant population densities. Natural hybridization events between the two cultivars were detected by phenotypically scoring plants in F(1) populations followed by verification with Mendelian segregation ratios in the F(1:2) families. PMGF was strongly associated with crop yield components, but showed no association with flowering synchrony. Maximum observed PMGF was always less than 0.6%, regardless of crop height and density. The frequency of PMGF in spring wheat decreased exponentially with increasing plant population density, but showed no dependence on either crop genotype or height. However, increasing plant densities beyond the recommended planting rate of 300 cropped wheat plants m(-2) provided no obvious benefit to reducing PMGF. Nevertheless, our results demonstrate a critical plant density of 175-200 cropped wheat plants m(-2) below which PMGF frequencies rise exponentially with decreasing plant density. These results will be useful in the development of mechanistic models and best management practices that collectively facilitate the coexistence of transgenic and nontransgenic wheat crops.

  16. Performance and cross-crop resistance of Cry1F-maize selected Spodoptera frugiperda on transgenic Bt cotton: implications for resistance management.

    Science.gov (United States)

    Yang, Fei; Kerns, David L; Brown, Sebe; Kurtz, Ryan; Dennehy, Tim; Braxton, Bo; Head, Graham; Huang, Fangneng

    2016-06-15

    Transgenic crops producing Bacillus thuringiensis (Bt) proteins have become a primary tool in pest management. Due to the intensive use of Bt crops, resistance of the fall armyworm, Spodoptera frugiperda, to Cry1F maize has occurred in Puerto Rico, Brazil, and some areas of the southeastern U.S. The sustainability of Bt crops faces a great challenge because the Cry1F-maize resistant S. frugiperda may also infest other Bt crops in multiple cropping ecosystems. Here we examined the survival and plant injury of a S. frugiperda population selected with Cry1F maize on three single-gene and five pyramided Bt cotton products. Larvae of Cry1F-susceptible (SS), -heterozygous (RS), and -resistant (RR) genotypes of S. frugiperda were all susceptible to the pyramided cotton containing Cry1Ac/Cry2Ab, Cry1Ac/Cry1F/Vip3A, Cry1Ab/Cry2Ae, or Cry1Ab/Cry2Ae/Vip3A, and the single-gene Cry2Ae cotton. Pyramided cotton containing Cry1Ac/Cry1F was effective against SS and RS, but not for RR. These findings show that the Cry1F-maize selected S. frugiperda can cause cross-crop resistance to other Bt crops expressing similar insecticidal proteins. Resistance management and pest management programs that utilize diversify mortality factors must be implemented to ensure the sustainability of Bt crops. This is especially important in areas where resistance to single-gene Bt crops is already widespread.

  17. Simulating changes in cropping practices in conventional and glyphosate-resistant maize. II. Weed impacts on crop production and biodiversity.

    Science.gov (United States)

    Colbach, Nathalie; Darmency, Henri; Fernier, Alice; Granger, Sylvie; Le Corre, Valérie; Messéan, Antoine

    2017-05-01

    Overreliance on the same herbicide mode of action leads to the spread of resistant weeds, which cancels the advantages of herbicide-tolerant (HT) crops. Here, the objective was to quantify, with simulations, the impact of glyphosate-resistant (GR) weeds on crop production and weed-related wild biodiversity in HT maize-based cropping systems differing in terms of management practices. We (1) simulated current conventional and probable HT cropping systems in two European regions, Aquitaine and Catalonia, with the weed dynamics model FLORSYS; (2) quantified how much the presence of GR weeds contributed to weed impacts on crop production and biodiversity; (3) determined the effect of cultural practices on the impact of GR weeds and (4) identified which species traits most influence weed-impact indicators. The simulation study showed that during the analysed 28 years, the advent of glyphosate resistance had little effect on plant biodiversity. Glyphosate-susceptible populations and species were replaced by GR ones. Including GR weeds only affected functional biodiversity (food offer for birds, bees and carabids) and weed harmfulness when weed effect was initially low; when weed effect was initially high, including GR weeds had little effect. The GR effect also depended on cultural practices, e.g. GR weeds were most detrimental for species equitability when maize was sown late. Species traits most harmful for crop production and most beneficial for biodiversity were identified, using RLQ analyses. None of the species presenting these traits belonged to a family for which glyphosate resistance was reported. An advice table was built; the effects of cultural practices on crop production and biodiversity were synthesized, explained, quantified and ranked, and the optimal choices for each management technique were identified.

  18. Vitamins for enhancing plant resistance.

    Science.gov (United States)

    Boubakri, Hatem; Gargouri, Mahmoud; Mliki, Ahmed; Brini, Faiçal; Chong, Julie; Jbara, Moez

    2016-09-01

    This paper provides an overview on vitamins with inducing activities in plants, the molecular and cellular mechanisms implicated, and the hormonal signalling-network regulating this process. Moreover, it reports how vitamins might be part of the molecular events linked to induced resistance by the conventional elicitors. Induced resistance (IR), exploiting the plant innate-defense system is a sustainable strategy for plant disease control. In the last decade, vitamins have been proven to act as inducers of disease resistance, and these findings have received an important attention owing to their safety and cost effectiveness. Vitamins, including thiamine (TH, vitamin B1), riboflavin (RF, vitamin B2), menadione sodium bisulfite (MSB, vitamin K3), Para-aminobenzoic acid (PABA, vitamin Bx), and folic acid (FA, vitamin B9) provided an efficient protection against a wide range of pathogens through the modulation of specific host-defense facets. However, other vitamins, such as ascorbic acid (AA, vitamin C) and tocopherols (vitamin E), have been shown to be a part of the molecular mechanisms associated to IR. The present review is the first to summarize what vitamins are acting as inducers of disease resistance in plants and how could they be modulated by the conventional elicitors. Thus, this report provides an overview on the protective abilities of vitamins and the molecular and cellular mechanisms underlying their activities. Moreover, it describes the hormonal-signalling network regulating vitamin-signal transduction during IR. Finally, a biochemical model describing how vitamins are involved in the establishment of IR process is discussed.

  19. Development of CRISPR/Cas9 mediated virus resistance in agriculturally important crops.

    Science.gov (United States)

    Khatodia, Surender; Bhatotia, Kirti; Tuteja, Narendra

    2017-05-04

    Clustered regulatory interspaced short palindromic repeats (CRISPR)/CRISPR associated nuclease 9 (Cas9) system of targeted genome editing has already revolutionized the plant science research. This is a RNA guided programmable endonuclease based system composed of 2 components, the Cas9 nuclease and an engineered guide RNA targeting any DNA sequence of the form N20-NGG for novel genome editing applications. The CRISPR/Cas9 technology of targeted genome editing has been recently applied for imparting virus resistance in plants. The robustness, wide adaptability, and easy engineering of this system has proved its potential as an antiviral tool for plants. Novel DNA free genome editing by using the preassembled Cas9/gRNA ribonucleoprotein complex for development of virus resistance in any plant species have been prospected for the future. Also, in this review we have discussed the reports of CRISPR/Cas9 mediated virus resistance strategy against geminiviruses by targeting the viral genome and transgene free strategy against RNA viruses by targeting the host plant factors. In conclusion, CRISPR/Cas9 technology will provide a more durable and broad spectrum viral resistance in agriculturally important crops which will eventually lead to public acceptance and commercialization in the near future.

  20. Effects of low doses of radiation on crop plants

    International Nuclear Information System (INIS)

    1966-01-01

    Claims for radiation-induced growth stimulations in plants have been made, starting almost from the time of the discovery of X-rays. However, there is general disagreement on this question, since the numerous studies designed to prove or disprove the existence of the phenomenon have produced inconclusively and erratic results. It is obvious that small, but significant, growth increases may be produced at times by ionizing radiations in certain crop plants, but such increases have not always been reproducible from one experiment to another, and marked inconsistencies often occur with regard to the optimal exposures to produce such effects. The purpose of the FAO/IAEA Panel meeting held in Rome on 1 June, 1964, was to review and evaluate the experimental results in this area and applications for increasing crop yields. Refs, figs and tabs

  1. RNA Silencing in Plants: Mechanisms, Technologies and Applications in Horticultural Crops.

    Science.gov (United States)

    Guo, Qigao; Liu, Qing; Smith, Neil A; Liang, Guolu; Wang, Ming-Bo

    2016-12-01

    Understanding the fundamental nature of a molecular process or a biological pathway is often a catalyst for the development of new technologies in biology. Indeed, studies from late 1990s to early 2000s have uncovered multiple overlapping but functionally distinct RNA silencing pathways in plants, including the posttranscriptional microRNA and small interfering RNA pathways and the transcriptional RNA-directed DNA methylation pathway. These findings have in turn been exploited for developing artificial RNA silencing technologies such as hairpin RNA, artificial microRNA, intrinsic direct repeat, 3' UTR inverted repeat, artificial trans-acting siRNA, and virus-induced gene silencing technologies. Some of these RNA silencing technologies, such as the hairpin RNA technology, have already been widely used for genetic improvement of crop plants in agriculture. For horticultural plants, RNA silencing technologies have been used to increase disease and pest resistance, alter plant architecture and flowering time, improve commercial traits of fruits and flowers, enhance nutritional values, remove toxic compounds and allergens, and develop high-value industrial products. In this article we aim to provide an overview of the RNA silencing pathways in plants, summarize the existing RNA silencing technologies, and review the current progress in applying these technologies for the improvement of agricultural crops particularly horticultural crops.

  2. Transgenerational Defense Priming for Crop Protection against Plant Pathogens: A Hypothesis.

    Science.gov (United States)

    Ramírez-Carrasco, Gabriela; Martínez-Aguilar, Keren; Alvarez-Venegas, Raúl

    2017-01-01

    Throughout evolution, plants have developed diverse mechanisms of defense that "prime" their innate immune system for more robust and active induction of defense responses against different types of stress. Nowadays there are numerous reports concerning the molecular bases of priming, as well as the generational priming mechanisms. Information concerning transgenerational priming, however, remains deficient. Some reports have indicated, nonetheless, that the priming status of a plant can be inherited to its offspring. Here, we show that the priming agent β-aminobutyric acid induced resistance to Pseudomonas syringae pv. phaseolicola infection in the common bean ( Phaseolus vulgaris L.) We have analyzed the transgenerational patterns of gene expression of the PvPR1 gene ( Phaseolus vulgaris PR1 ), a highly responsive gene to priming, and show that a transgenerational priming response against pathogen attack can last for at least two generations. We hypothesize that a defense-resistant phenotype and easily identifiable, generational and transgenerational, "primed patterns" of gene expression are excellent indicators of the priming response in crop plants. Furthermore, we propose here that modern plant breeding methods and crop improvement efforts must include the use of elicitors to prime induced resistance in the field and, above all, to select for induced heritable states in progeny that is primed for defense.

  3. Insect-resistant biotech crops and their impacts on beneficial arthropods

    Science.gov (United States)

    Gatehouse, A. M. R.; Ferry, N.; Edwards, M. G.; Bell, H. A.

    2011-01-01

    With a projected population of 10 billion by 2050, an immediate priority for agriculture is to achieve increased crop yields in a sustainable and cost-effective way. The concept of using a transgenic approach was realized in the mid-1990s with the commercial introduction of genetically modified (GM) crops. By 2010, the global value of the seed alone was US $11.2 billion, with commercial biotech maize, soya bean grain and cotton valued at approximately US $150 billion. In recent years, it has become evident that insect-resistant crops expressing δ-endotoxin genes from Bacillus thuringiensis have made a significant beneficial impact on global agriculture, not least in terms of pest reduction and improved quality. However, because of the potential for pest populations to evolve resistance, and owing to lack of effective control of homopteran pests, alternative strategies are being developed. Some of these are based on Bacillus spp. or other insect pathogens, while others are based on the use of plant- and animal-derived genes. However, if such approaches are to play a useful role in crop protection, it is desirable that they do not have a negative impact on beneficial organisms at higher trophic levels thus affecting the functioning of the agro-ecosystem. This widely held concern over the ecological impacts of GM crops has led to the extensive examination of the potential effects of a range of transgene proteins on non-target and beneficial insects. The findings to date with respect to both commercial and experimental GM crops expressing anti-insect genes are discussed here, with particular emphasis on insect predators and parasitoids. PMID:21444317

  4. Role of soil, crop debris, and a plant pathogen in Salmonella enterica contamination of tomato plants.

    Directory of Open Access Journals (Sweden)

    Jeri D Barak

    Full Text Available BACKGROUND: In the U.S., tomatoes have become the most implicated vehicle for produce-associated Salmonellosis with 12 outbreaks since 1998. Although unconfirmed, trace backs suggest pre-harvest contamination with Salmonella enterica. Routes of tomato crop contamination by S. enterica in the absence of direct artificial inoculation have not been investigated. METHODOLOGY/PRINCIPAL FINDINGS: This work examined the role of contaminated soil, the potential for crop debris to act as inoculum from one crop to the next, and any interaction between the seedbourne plant pathogen Xanthomonas campestris pv. vesicatoria and S. enterica on tomato plants. Our results show S. enterica can survive for up to six weeks in fallow soil with the ability to contaminate tomato plants. We found S. enterica can contaminate a subsequent crop via crop debris; however a fallow period between crop incorporation and subsequent seeding can affect contamination patterns. Throughout these studies, populations of S. enterica declined over time and there was no bacterial growth in either the phyllosphere or rhizoplane. The presence of X. campestris pv. vesicatoria on co-colonized tomato plants had no effect on the incidence of S. enterica tomato phyllosphere contamination. However, growth of S. enterica in the tomato phyllosphere occurred on co-colonized plants in the absence of plant disease. CONCLUSIONS/SIGNIFICANCE: S. enterica contaminated soil can lead to contamination of the tomato phyllosphere. A six week lag period between soil contamination and tomato seeding did not deter subsequent crop contamination. In the absence of plant disease, presence of the bacterial plant pathogen, X. campestris pv. vesicatoria was beneficial to S. enterica allowing multiplication of the human pathogen population. Any event leading to soil contamination with S. enterica could pose a public health risk with subsequent tomato production, especially in areas prone to bacterial spot disease.

  5. Plant-pathogen interactions: toward development of next-generation disease-resistant plants.

    Science.gov (United States)

    Nejat, Naghmeh; Rookes, James; Mantri, Nitin L; Cahill, David M

    2017-03-01

    Briskly evolving phytopathogens are dire threats to our food supplies and threaten global food security. From the recent advances made toward high-throughput sequencing technologies, understanding of pathogenesis and effector biology, and plant innate immunity, translation of these means into new control tools is being introduced to develop durable disease resistance. Effectoromics as a powerful genetic tool for uncovering effector-target genes, both susceptibility genes and executor resistance genes in effector-assisted breeding, open up new avenues to improve resistance. TALENs (Transcription Activator-Like Effector Nucleases), engineered nucleases and CRISPR (Clustered Regulatory Interspaced Short Palindromic Repeats)/Cas9 systems are breakthrough and powerful techniques for genome editing, providing efficient mechanisms for targeted crop protection strategies in disease resistance programs. In this review, major advances in plant disease management to confer durable disease resistance and novel strategies for boosting plant innate immunity are highlighted.

  6. Combining pest control and resistance management: synergy of engineered insects with Bt crops.

    Science.gov (United States)

    Alphey, Nina; Bonsall, Michael B; Alphey, Luke

    2009-04-01

    Transgenic crops producing insecticidal toxins are widely used to control insect pests. Their benefits would be lost if resistance to the toxins became widespread in pest populations. The most widely used resistance management method is the high-dose/refuge strategy. This requires toxin-free host plants as refuges near insecticidal crops, and toxin doses intended to be sufficiently high to kill insects heterozygous for a resistant allele, thereby rendering resistance functionally recessive. We have previously shown by mathematical modeling that mass-release of harmless susceptible (toxin-sensitive) insects engineered with repressible female-specific lethality using release of insects carrying a dominant lethal ([RIDL] Oxitec Limited, United Kingdom) technology could substantially delay or reverse the spread of resistance and reduce refuge sizes. Here, we explore this proposal in depth, studying a wide range of scenarios, considering impacts on population dynamics as well as evolution of allele frequencies, comparing with releases of natural fertile susceptible insects, and examining the effect of seasonality. We investigate the outcome for pest control for which the plant-incorporated toxins are not necessarily at a high dose (i.e., they might not kill all homozygous susceptible and all heterozygous insects). We demonstrate that a RIDL-based approach could form an effective component of a resistance management strategy in a wide range of genetic and ecological circumstances. Because there are significant threshold effects for several variables, we expect that a margin of error would be advisable in setting release ratios and refuge sizes, especially as the frequency and properties of resistant alleles may be difficult to measure accurately in the field.

  7. Assessment of the phytoextraction potential of high biomass crop plants.

    Science.gov (United States)

    Hernández-Allica, Javier; Becerril, José M; Garbisu, Carlos

    2008-03-01

    A hydroponic screening method was used to identify high biomass crop plants with the ability to accumulate metals. Highest values of shoot accumulation were found in maize cv. Ranchero, rapeseed cv. Karat, and cardoon cv. Peralta for Pb (18 753 mg kg(-1)), Zn (10 916 mg kg(-1)), and Cd (242 mg kg(-1)), respectively. Subsequently, we tested the potential of these three cultivars for the phytoextraction of a metal spiked compost, finding out that, in cardoon and maize plants, increasing Zn and Cd concentrations led to lower values of root and shoot DW. By contrast, rapeseed shoot growth was not significantly affected by Cd concentration. Finally, a metal polluted soil was used to check these cultivars' phytoextraction capacity. Although the soil was phytotoxic enough to prevent the growth of cardoon and rapeseed plants, maize plants phytoextracted 3.7 mg Zn pot(-1). We concluded that the phytoextraction performance of cultivars varies depending on the screening method used.

  8. Public Acceptance of Plant Biotechnology and GM Crops.

    Science.gov (United States)

    Lucht, Jan M

    2015-07-30

    A wide gap exists between the rapid acceptance of genetically modified (GM) crops for cultivation by farmers in many countries and in the global markets for food and feed, and the often-limited acceptance by consumers. This review contrasts the advances of practical applications of agricultural biotechnology with the divergent paths-also affecting the development of virus resistant transgenic crops-of political and regulatory frameworks for GM crops and food in different parts of the world. These have also shaped the different opinions of consumers. Important factors influencing consumer's attitudes are the perception of risks and benefits, knowledge and trust, and personal values. Recent political and societal developments show a hardening of the negative environment for agricultural biotechnology in Europe, a growing discussion-including calls for labeling of GM food-in the USA, and a careful development in China towards a possible authorization of GM rice that takes the societal discussions into account. New breeding techniques address some consumers' concerns with transgenic crops, but it is not clear yet how consumers' attitudes towards them will develop. Discussions about agriculture would be more productive, if they would focus less on technologies, but on common aims and underlying values.

  9. Potential of in vitro mutation breeding for the improvement of vegetatively propagated crop plants

    International Nuclear Information System (INIS)

    Constantin, M.J.

    1984-01-01

    Significant progress has been realized in a number of technologies (e.g., protoplast cultures), collectively referred to as plant cell and tissue culture, within the last decade. In vitro culture technologies offer great potentials for the improvement of crop plants, both sexually and asexually propagated; however, to realize these potentials plant regeneration from selected cells must be achieved for the species of interest. Where whole plants have been regenerated from selected cells, the mutant trait was expressed in some but not in all cases, and the inheritance patterns included maternal, recessive, semi-dominant and dominant (epigenetic events have also been reported). Improved cultivars of sugarcane have been developed from in vitro culture selections. In vitro mutation breeding can be done using an array of physical and chemical mutagens that has been found to be effective in the treatment of seeds, pollen, vegetative plant parts and growing plants. Selection at the cell level for a range of mutant traits has been demonstrated; however, innovative selection schemes will have to be developed to select for agriculturally important traits such as date of maturity, resistance to lodging, height etc. An interdisciplinary team approach involving the combined use of in vitro culture technology, mutagenesis, and plant breeding/genetics offers the greatest probability for success in crop improvement. (author)

  10. Host Plant Resistance to Green Peach Aphid, Myzus persicae (Sulzar), by Some Wild Types of Watermelon

    Science.gov (United States)

    The green peach aphid, Myzus persicae (Sulzar), is an important pest of many vegetable crops. It damages crops by feeding and vectoring viruses. Potential sources of plant resistance against M. persicae were examined for watermelon. A multiple choice experiment was conducted with leaves of six wi...

  11. Not all GMOs are crop plants: non-plant GMO applications in agriculture

    Science.gov (United States)

    In the time since the tools of modern biotechnology have become available, the most commonly applied and often discussed genetically modified organisms are genetically modified crop plants, although genetic engineering is also being used successfully in organisms other than plants, including bacteri...

  12. Safeguarding crop plant production with the aid of nuclear techniques

    International Nuclear Information System (INIS)

    1977-01-01

    The international symposium on induced mutations was organized jointly by IAEA, FAO and the Swedish International Development Authority (SIDA). The participants discussed primarily the methodology and problems related to the use of radiation and tracer techniques for breeding crop varieties with improved disease resistance. Scientists from 41 countries and international organizations participated. But not only were problems, methodology and various approaches discussed, some scientists were able to report positive and practically useful results. Rice mutants with better resistance against blast, leaf blight and sclerotic disease were reported (India, Japan, Korea, France). Improved tolerance to septoria in wheat and to crown rust in oats has been found (Switzerland, USA) and convincing evidence was given that non-specific, medium-level resistance to mildew can be induced in barley (FRG). A potato mutant resistant to wart disease was found in the USSR, and a wheat mutant with improved resistance to stem and stripe rust has been released to farmers in Greece. Among the economically important positive results is the selection of spearmint resistant to Verticillium wilt. (USA). This success follows a similar one in peppermint achieved several years ago, which now represents a gain of about one million dollars per year to growers in the USA

  13. Genome editing and plant transformation of solanaceous food crops.

    Science.gov (United States)

    Van Eck, Joyce

    2018-02-01

    During the past decade, the ability to alter plant genomes in a DNA site-specific manner was realized through availability of sequenced genomes and emergence of editing technologies based on complexes that guide endonucleases. Generation of targeted DNA breaks by ZFNs, TALENs, and CRISPR/Cas9, then mending by repair mechanisms, provides a valuable foundation for studies of gene function and trait modification. Genome editing has been successful in several food crops, including those belonging to the Solanaceae, which contains some of the most widely used, economically important ones such as tomato and potato. Application of new breeding technologies has the potential to not only address deficiencies of current crops, but to also transform underutilized species into viable sources to diversify and strengthen our food supply. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Resistance mechanisms to plant viruses: an overview

    NARCIS (Netherlands)

    Goldbach, R.W.; Bucher, E.C.; Prins, A.H.

    2003-01-01

    To obtain virus-resistant host plants, a range of operational strategies can be followed nowadays. While for decades plant breeders have been able to introduce natural resistance genes in susceptible genotypes without knowing precisely what these resistance traits were, currently a growing number of

  15. Plant growth promotion in cereal and leguminous agricultural important plants: from microorganism capacities to crop production.

    Science.gov (United States)

    Pérez-Montaño, F; Alías-Villegas, C; Bellogín, R A; del Cerro, P; Espuny, M R; Jiménez-Guerrero, I; López-Baena, F J; Ollero, F J; Cubo, T

    2014-01-01

    Plant growth-promoting rhizobacteria (PGPR) are free-living bacteria which actively colonize plant roots, exerting beneficial effects on plant development. The PGPR may (i) promote the plant growth either by using their own metabolism (solubilizing phosphates, producing hormones or fixing nitrogen) or directly affecting the plant metabolism (increasing the uptake of water and minerals), enhancing root development, increasing the enzymatic activity of the plant or "helping" other beneficial microorganisms to enhance their action on the plants; (ii) or may promote the plant growth by suppressing plant pathogens. These abilities are of great agriculture importance in terms of improving soil fertility and crop yield, thus reducing the negative impact of chemical fertilizers on the environment. The progress in the last decade in using PGPR in a variety of plants (maize, rice, wheat, soybean and bean) along with their mechanism of action are summarized and discussed here. Copyright © 2013 Elsevier GmbH. All rights reserved.

  16. The Development of a Remote Sensor System and Decision Support Systems Architecture to Monitor Resistance Development in Transgenic Crops

    Science.gov (United States)

    Cacas, Joseph; Glaser, John; Copenhaver, Kenneth; May, George; Stephens, Karen

    2008-01-01

    The United States Environmental Protection Agency (EPA) has declared that "significant benefits accrue to growers, the public, and the environment" from the use of transgenic pesticidal crops due to reductions in pesticide usage for crop pest management. Large increases in the global use of transgenic pesticidal crops has reduced the amounts of broad spectrum pesticides used to manage pest populations, improved yield and reduced the environmental impact of crop management. A significant threat to the continued use of this technology is the evolution of resistance in insect pest populations to the insecticidal Bt toxins expressed by the plants. Management of transgenic pesticidal crops with an emphasis on conservation of Bt toxicity in field populations of insect pests is important to the future of sustainable agriculture. A vital component of this transgenic pesticidal crop management is establishing the proof of concept basic understanding, situational awareness, and monitoring and decision support system tools for more than 133650 square kilometers (33 million acres) of bio-engineered corn and cotton for development of insect resistance . Early and recent joint NASA, US EPA and ITD remote imagery flights and ground based field experiments have provided very promising research results that will potentially address future requirements for crop management capabilities.

  17. Small RNAs in plants: Recent development and application for crop improvement

    Directory of Open Access Journals (Sweden)

    Ayushi eKamthan

    2015-04-01

    Full Text Available The phenomenon of RNA interference (RNAi which involves sequence specific gene regulation by small non-coding RNAs i.e small interfering RNA (siRNA and micro RNA (miRNA has emerged as one of most powerful approaches for crop improvement. RNAi based on siRNA is one of the widely used tools of reverse genetics which aid in revealing gene functions in many species. This technology has been extensively applied to alter the gene expression in plants with an aim to achieve desirable traits. RNAi has been used for enhancing the crop yield and productivity by manipulating the gene involved in biomass, grain yield and enhanced shelf life of fruits & vegetables. It has also been applied for developing resistance against various biotic (bacteria, fungi, viruses, nematodes, insects and abiotic stresses (drought, salinity, cold etc.. Nutritional improvements of crops have also been achieved by enriching the crops with essential amino acids, fatty acids, antioxidants and other nutrients beneficial for human health or by reducing allergens or anti-nutrients. Micro RNAs are key regulators of important plant processes like growth, development and response to various stresses. In spite of similarity in size (20-24nt, miRNA differ from siRNA in precursor structures, pathway of biogenesis, and modes of action. This review also highlights the miRNA based genetic modification technology where various miRNAs/artificial miRNAs and their targets can be utilized for improving several desirable plant traits. Micro RNA based strategies are much efficient than siRNA-based RNAi strategies due to its specificity and less undesirable off target effects. As per the FDA guidelines, small RNA based transgenics are much safer for consumption than those over expressing proteins. This review thereby summarizes the emerging advances and achievement in the field of small RNAs and its application for crop improvement.

  18. Small RNAs in plants: recent development and application for crop improvement.

    Science.gov (United States)

    Kamthan, Ayushi; Chaudhuri, Abira; Kamthan, Mohan; Datta, Asis

    2015-01-01

    The phenomenon of RNA interference (RNAi) which involves sequence-specific gene regulation by small non-coding RNAs, i.e., small interfering RNA (siRNA) and microRNA (miRNA) has emerged as one of most powerful approaches for crop improvement. RNAi based on siRNA is one of the widely used tools of reverse genetics which aid in revealing gene functions in many species. This technology has been extensively applied to alter the gene expression in plants with an aim to achieve desirable traits. RNAi has been used for enhancing the crop yield and productivity by manipulating the gene involved in biomass, grain yield and enhanced shelf life of fruits and vegetables. It has also been applied for developing resistance against various biotic (bacteria, fungi, viruses, nematodes, insects) and abiotic stresses (drought, salinity, cold, etc.). Nutritional improvements of crops have also been achieved by enriching the crops with essential amino acids, fatty acids, antioxidants and other nutrients beneficial for human health or by reducing allergens or anti-nutrients. microRNAs are key regulators of important plant processes like growth, development, and response to various stresses. In spite of similarity in size (20-24 nt), miRNA differ from siRNA in precursor structures, pathway of biogenesis, and modes of action. This review also highlights the miRNA based genetic modification technology where various miRNAs/artificial miRNAs and their targets can be utilized for improving several desirable plant traits. microRNA based strategies are much efficient than siRNA-based RNAi strategies due to its specificity and less undesirable off target effects. As per the FDA guidelines, small RNA (sRNA) based transgenics are much safer for consumption than those over-expressing proteins. This review thereby summarizes the emerging advances and achievement in the field of sRNAs and its application for crop improvement.

  19. Engineering Mycorrhizal Symbioses to Alter Plant Metabolism and Improve Crop Health

    Directory of Open Access Journals (Sweden)

    Katherine E. French

    2017-07-01

    Full Text Available Creating sustainable bioeconomies for the 21st century relies on optimizing the use of biological resources to improve agricultural productivity and create new products. Arbuscular mycorrhizae (phylum Glomeromycota form symbiotic relationships with over 80% of vascular plants. In return for carbon, these fungi improve plant health and tolerance to environmental stress. This symbiosis is over 400 million years old and there are currently over 200 known arbuscular mycorrhizae, with dozens of new species described annually. Metagenomic sequencing of native soil communities, from species-rich meadows to mangroves, suggests biologically diverse habitats support a variety of mycorrhizal species with potential agricultural, medical, and biotechnological applications. This review looks at the effect of mycorrhizae on plant metabolism and how we can harness this symbiosis to improve crop health. I will first describe the mechanisms that underlie this symbiosis and what physiological, metabolic, and environmental factors trigger these plant-fungal relationships. These include mycorrhizal manipulation of host genetic expression, host mitochondrial and plastid proliferation, and increased production of terpenoids and jasmonic acid by the host plant. I will then discuss the effects of mycorrhizae on plant root and foliar secondary metabolism. I subsequently outline how mycorrhizae induce three key benefits in crops: defense against pathogen and herbivore attack, drought resistance, and heavy metal tolerance. I conclude with an overview of current efforts to harness mycorrhizal diversity to improve crop health through customized inoculum. I argue future research should embrace synthetic biology to create mycorrhizal chasses with improved symbiotic abilities and potentially novel functions to improve plant health. As the effects of climate change and anthropogenic disturbance increase, the global diversity of arbuscular mycorrhizal fungi should be monitored

  20. Engineering Mycorrhizal Symbioses to Alter Plant Metabolism and Improve Crop Health.

    Science.gov (United States)

    French, Katherine E

    2017-01-01

    Creating sustainable bioeconomies for the 21st century relies on optimizing the use of biological resources to improve agricultural productivity and create new products. Arbuscular mycorrhizae (phylum Glomeromycota) form symbiotic relationships with over 80% of vascular plants. In return for carbon, these fungi improve plant health and tolerance to environmental stress. This symbiosis is over 400 million years old and there are currently over 200 known arbuscular mycorrhizae, with dozens of new species described annually. Metagenomic sequencing of native soil communities, from species-rich meadows to mangroves, suggests biologically diverse habitats support a variety of mycorrhizal species with potential agricultural, medical, and biotechnological applications. This review looks at the effect of mycorrhizae on plant metabolism and how we can harness this symbiosis to improve crop health. I will first describe the mechanisms that underlie this symbiosis and what physiological, metabolic, and environmental factors trigger these plant-fungal relationships. These include mycorrhizal manipulation of host genetic expression, host mitochondrial and plastid proliferation, and increased production of terpenoids and jasmonic acid by the host plant. I will then discuss the effects of mycorrhizae on plant root and foliar secondary metabolism. I subsequently outline how mycorrhizae induce three key benefits in crops: defense against pathogen and herbivore attack, drought resistance, and heavy metal tolerance. I conclude with an overview of current efforts to harness mycorrhizal diversity to improve crop health through customized inoculum. I argue future research should embrace synthetic biology to create mycorrhizal chasses with improved symbiotic abilities and potentially novel functions to improve plant health. As the effects of climate change and anthropogenic disturbance increase, the global diversity of arbuscular mycorrhizal fungi should be monitored and protected to

  1. Engineering Mycorrhizal Symbioses to Alter Plant Metabolism and Improve Crop Health

    Science.gov (United States)

    French, Katherine E.

    2017-01-01

    Creating sustainable bioeconomies for the 21st century relies on optimizing the use of biological resources to improve agricultural productivity and create new products. Arbuscular mycorrhizae (phylum Glomeromycota) form symbiotic relationships with over 80% of vascular plants. In return for carbon, these fungi improve plant health and tolerance to environmental stress. This symbiosis is over 400 million years old and there are currently over 200 known arbuscular mycorrhizae, with dozens of new species described annually. Metagenomic sequencing of native soil communities, from species-rich meadows to mangroves, suggests biologically diverse habitats support a variety of mycorrhizal species with potential agricultural, medical, and biotechnological applications. This review looks at the effect of mycorrhizae on plant metabolism and how we can harness this symbiosis to improve crop health. I will first describe the mechanisms that underlie this symbiosis and what physiological, metabolic, and environmental factors trigger these plant-fungal relationships. These include mycorrhizal manipulation of host genetic expression, host mitochondrial and plastid proliferation, and increased production of terpenoids and jasmonic acid by the host plant. I will then discuss the effects of mycorrhizae on plant root and foliar secondary metabolism. I subsequently outline how mycorrhizae induce three key benefits in crops: defense against pathogen and herbivore attack, drought resistance, and heavy metal tolerance. I conclude with an overview of current efforts to harness mycorrhizal diversity to improve crop health through customized inoculum. I argue future research should embrace synthetic biology to create mycorrhizal chasses with improved symbiotic abilities and potentially novel functions to improve plant health. As the effects of climate change and anthropogenic disturbance increase, the global diversity of arbuscular mycorrhizal fungi should be monitored and protected to

  2. Public Acceptance of Plant Biotechnology and GM Crops

    Directory of Open Access Journals (Sweden)

    Jan M. Lucht

    2015-07-01

    Full Text Available A wide gap exists between the rapid acceptance of genetically modified (GM crops for cultivation by farmers in many countries and in the global markets for food and feed, and the often-limited acceptance by consumers. This review contrasts the advances of practical applications of agricultural biotechnology with the divergent paths—also affecting the development of virus resistant transgenic crops—of political and regulatory frameworks for GM crops and food in different parts of the world. These have also shaped the different opinions of consumers. Important factors influencing consumer’s attitudes are the perception of risks and benefits, knowledge and trust, and personal values. Recent political and societal developments show a hardening of the negative environment for agricultural biotechnology in Europe, a growing discussion—including calls for labeling of GM food—in the USA, and a careful development in China towards a possible authorization of GM rice that takes the societal discussions into account. New breeding techniques address some consumers’ concerns with transgenic crops, but it is not clear yet how consumers’ attitudes towards them will develop. Discussions about agriculture would be more productive, if they would focus less on technologies, but on common aims and underlying values.

  3. Public Acceptance of Plant Biotechnology and GM Crops

    Science.gov (United States)

    Lucht, Jan M.

    2015-01-01

    A wide gap exists between the rapid acceptance of genetically modified (GM) crops for cultivation by farmers in many countries and in the global markets for food and feed, and the often-limited acceptance by consumers. This review contrasts the advances of practical applications of agricultural biotechnology with the divergent paths—also affecting the development of virus resistant transgenic crops—of political and regulatory frameworks for GM crops and food in different parts of the world. These have also shaped the different opinions of consumers. Important factors influencing consumer’s attitudes are the perception of risks and benefits, knowledge and trust, and personal values. Recent political and societal developments show a hardening of the negative environment for agricultural biotechnology in Europe, a growing discussion—including calls for labeling of GM food—in the USA, and a careful development in China towards a possible authorization of GM rice that takes the societal discussions into account. New breeding techniques address some consumers’ concerns with transgenic crops, but it is not clear yet how consumers’ attitudes towards them will develop. Discussions about agriculture would be more productive, if they would focus less on technologies, but on common aims and underlying values. PMID:26264020

  4. The Lr34 adult plant rust resistance gene provides seedling resistance in durum wheat without senescence.

    Science.gov (United States)

    Rinaldo, Amy; Gilbert, Brian; Boni, Rainer; Krattinger, Simon G; Singh, Davinder; Park, Robert F; Lagudah, Evans; Ayliffe, Michael

    2017-07-01

    The hexaploid wheat (Triticum aestivum) adult plant resistance gene, Lr34/Yr18/Sr57/Pm38/Ltn1, provides broad-spectrum resistance to wheat leaf rust (Lr34), stripe rust (Yr18), stem rust (Sr57) and powdery mildew (Pm38) pathogens, and has remained effective in wheat crops for many decades. The partial resistance provided by this gene is only apparent in adult plants and not effective in field-grown seedlings. Lr34 also causes leaf tip necrosis (Ltn1) in mature adult plant leaves when grown under field conditions. This D genome-encoded bread wheat gene was transferred to tetraploid durum wheat (T. turgidum) cultivar Stewart by transformation. Transgenic durum lines were produced with elevated gene expression levels when compared with the endogenous hexaploid gene. Unlike nontransgenic hexaploid and durum control lines, these transgenic plants showed robust seedling resistance to pathogens causing wheat leaf rust, stripe rust and powdery mildew disease. The effectiveness of seedling resistance against each pathogen correlated with the level of transgene expression. No evidence of accelerated leaf necrosis or up-regulation of senescence gene markers was apparent in these seedlings, suggesting senescence is not required for Lr34 resistance, although leaf tip necrosis occurred in mature plant flag leaves. Several abiotic stress-response genes were up-regulated in these seedlings in the absence of rust infection as previously observed in adult plant flag leaves of hexaploid wheat. Increasing day length significantly increased Lr34 seedling resistance. These data demonstrate that expression of a highly durable, broad-spectrum adult plant resistance gene can be modified to provide seedling resistance in durum wheat. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  5. Biosafety risk assessment approaches for insect-resistant genetically modified crops

    Directory of Open Access Journals (Sweden)

    Inaam Ullah

    2017-02-01

    Full Text Available Background: Environmental risk assessment (ERA is imperative for commercial release of insect resistant, genetically modified crops (IR-GMCs.An insect specific, spider venom peptideω-HXTX-Hv1a (Hvt was successfully expressed in cotton plants. The cotton plants producing Hvt protein have demonstrated resistance against economically important insect pest species. The study was performed to assess the effects of Hvt producing cotton plants on Honey bees (Apis mellifera. Methods: Three approaches were used to evaluate the effects of Hvt protein on adults of honeybees; whole plant assays in flight cages, in vitro assays with pollen of Hvt-cotton, and assays with elevated levels of purified Hvt protein. Pollens of Bt cotton or purified Bt proteins were used as control. Results: The field experiments did not yield any meaningful data due to high rate of mortality in all treatments including the control. However, the laboratory experiments provided conclusive results in which Hvt, purified or in pollens, did not affect the survival or longevity of the bees compared to the control. During the course of study we were able to compare the quality, effectiveness and economics of different experiments. Conclusions: We conclude that Hvt either purified or produced in cotton plants do not affect the survival or longevity of honey bees. We are also of the view that starting at laboratory level assays not only gives meaningful data but also saves a lot of time and money that can be spent on other important questions regarding safety of a particular transgenic crop. Hence, a purpose-based, tiered approach could be the best choice for pre-release ERA of IR-GMCs.

  6. Opportunities for improving phosphorus-use efficiency in crop plants.

    Science.gov (United States)

    Veneklaas, Erik J; Lambers, Hans; Bragg, Jason; Finnegan, Patrick M; Lovelock, Catherine E; Plaxton, William C; Price, Charles A; Scheible, Wolf-Rüdiger; Shane, Michael W; White, Philip J; Raven, John A

    2012-07-01

    Limitation of grain crop productivity by phosphorus (P) is widespread and will probably increase in the future. Enhanced P efficiency can be achieved by improved uptake of phosphate from soil (P-acquisition efficiency) and by improved productivity per unit P taken up (P-use efficiency). This review focuses on improved P-use efficiency, which can be achieved by plants that have overall lower P concentrations, and by optimal distribution and redistribution of P in the plant allowing maximum growth and biomass allocation to harvestable plant parts. Significant decreases in plant P pools may be possible, for example, through reductions of superfluous ribosomal RNA and replacement of phospholipids by sulfolipids and galactolipids. Improvements in P distribution within the plant may be possible by increased remobilization from tissues that no longer need it (e.g. senescing leaves) and reduced partitioning of P to developing grains. Such changes would prolong and enhance the productive use of P in photosynthesis and have nutritional and environmental benefits. Research considering physiological, metabolic, molecular biological, genetic and phylogenetic aspects of P-use efficiency is urgently needed to allow significant progress to be made in our understanding of this complex trait. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

  7. Concentration-dependent RDX uptake and remediation by crop plants.

    Science.gov (United States)

    Chen, Diejun; Liu, Z Lewis; Banwart, Wanye

    2011-07-01

    The potential RDX contamination of food chain from polluted soil is a significant concern in regards to both human health and environment. Using a hydroponic system and selected soils spiked with RDX, this study disclosed that four crop plant species maize (Zea mays), sorghum (Sorghum sudanese), wheat (Triticum aestivum), and soybean (Glycine max) were capable of RDX uptake with more in aerial parts than roots. The accumulation of RDX in the plant tissue is concentration-dependent up to 21 mg RDX/L solution or 100 mg RDX/kg soil but not proportionally at higher RDX levels from 220 to 903 mg/kg soil. While wheat plant tissue harbored the highest RDX concentration of 2,800 μg per gram dry biomass, maize was able to remove a maximum of 3,267 μg RDX from soil per pot by five 4-week plants at 100 mg/kg of soil. Although RDX is toxic to plants, maize, sorghum, and wheat showed reasonable growth in the presence of the chemical, whereas soybeans were more sensitive to RDX. Results of this study facilitate assessment of the potential invasion of food chain by RDX-contaminated soils.

  8. Paraquat resistance of transgenic tobacco plants over-expressing the Ochrobactrum anthropi pqrA gene.

    Science.gov (United States)

    Jo, Jinki; Won, Sung-Hye; Son, Daeyoung; Lee, Byung-Hyun

    2004-09-01

    Transgenic tobacco plants over-expressing the Ochrobactrum anthropi pqrA gene, which encodes a membrane transporter mediating resistance to paraquat, were generated. Transgenic plants displayed higher resistance against paraquat than wild-type plants, as estimated by plant viability, ion leakage and chlorophyll loss, but no resistance against other active oxygen generators, such as H2O2 and menadione. Moreover, lower levels of paraquat accumulated in transgenic plants, compared to wild-type plants, indicating that the PqrA protein detoxifies paraquat either via increased efflux or decreased uptake of the herbicide, but not by removing active oxygen species. The results collectively demonstrate that the bacterial paraquat resistance gene, pqrA, can be functionally expressed in plant cells, and utilized for the development of paraquat-resistant crop plants.

  9. Biotechnological applications in in vitro plant regeneration studies of broccoli (Brassica oleracea L. var. italica), an important vegetable crop.

    Science.gov (United States)

    Kumar, Pankaj; Srivastava, Dinesh Kumar

    2016-04-01

    Biotechnology holds promise for genetic improvement of important vegetable crops. Broccoli (Brassica oleracea L. var. italica) is an important vegetable crop of the family Brassicaceae. However, various biotic and abiotic stresses cause enormous crop yield losses during commercial cultivation of broccoli. Establishment of a reliable, reproducible and efficient in vitro plant regeneration system with cell and tissue culture is a vital prerequisite for biotechnological application of crop improvement programme. An in vitro plant regeneration technique refers to culturing, cell division, cell multiplication, de-differentiation and differentiation of cells, protoplasts, tissues and organs on defined liquid/solid medium under aseptic and controlled environment. Recent progress in the field of plant tissue culture has made this area one of the most dynamic and promising in experimental biology. There are many published reports on in vitro plant regeneration studies in broccoli including direct organogenesis, indirect organogenesis and somatic embryogenesis. This review summarizes those plant regeneration studies in broccoli that could be helpful in drawing the attention of the researchers and scientists to work on it to produce healthy, biotic and abiotic stress resistant plant material and to carry out genetic transformation studies for the production of transgenic plants.

  10. Climate driven crop planting date in the ACME Land Model (ALM): Impacts on productivity and yield

    Science.gov (United States)

    Drewniak, B.

    2017-12-01

    Climate is one of the key drivers of crop suitability and productivity in a region. The influence of climate and weather on the growing season determine the amount of time crops spend in each growth phase, which in turn impacts productivity and, more importantly, yields. Planting date can have a strong influence on yields with earlier planting generally resulting in higher yields, a sensitivity that is also present in some crop models. Furthermore, planting date is already changing and may continue, especially if longer growing seasons caused by future climate change drive early (or late) planting decisions. Crop models need an accurate method to predict plant date to allow these models to: 1) capture changes in crop management to adapt to climate change, 2) accurately model the timing of crop phenology, and 3) improve crop simulated influences on carbon, nutrient, energy, and water cycles. Previous studies have used climate as a predictor for planting date. Climate as a plant date predictor has more advantages than fixed plant dates. For example, crop expansion and other changes in land use (e.g., due to changing temperature conditions), can be accommodated without additional model inputs. As such, a new methodology to implement a predictive planting date based on climate inputs is added to the Accelerated Climate Model for Energy (ACME) Land Model (ALM). The model considers two main sources of climate data important for planting: precipitation and temperature. This method expands the current temperature threshold planting trigger and improves the estimated plant date in ALM. Furthermore, the precipitation metric for planting, which synchronizes the crop growing season with the wettest months, allows tropical crops to be introduced to the model. This presentation will demonstrate how the improved model enhances the ability of ALM to capture planting date compared with observations. More importantly, the impact of changing the planting date and introducing tropical

  11. Plant biotechnology for deeper understanding, wider use and further development of agricultural and horticultural crops

    Directory of Open Access Journals (Sweden)

    P. ELOMAA

    2008-12-01

    Full Text Available Plants bind solar energy to organic matter via photosynthesis and assimilation of carbon dioxide from the atmosphere and comprise the major source of nutrition and bioenergy. Plant biotechnology contributes to solution of important constraints in food and feed production and creates new technologies and applications for the sustainable use of plant resources. Genome-wide approaches such as massive parallel sequencing and microarrays to study gene expression, molecular markers for selection of important traits in breeding, characterization of genetic diversity with the aforementioned approaches, and somatic hybridization and genetic transformation are important tools in plant biotechnology. In this paper, studies carried out on enhanced resistance to viruses and tolerance of cold stress in potato, genetic modification of flower pigmentation and morphology in gerbera, production of edible vaccines in transgenic barley seeds, and expression of heterologous proteins for pharmaceutical purposes from vector viruses were chosen to exemplify the general utility of biotechnological approaches and also how plant biotechnology research has developed on cultivated plants at University of Helsinki. The studies reveal cellular and genetic mechanisms and provide scientific information that can be used for widening the uses of crop plants. They can also be used to detect any putative risks associated with the use of the biotechnological application in agriculture and horticulture and to develop practises which reduce any inadvertent negative consequences that plant production may have to the environment.;

  12. Assessment of the phytoextraction potential of high biomass crop plants

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez-Allica, Javier [NEIKER-tecnalia, Basque Institute of Agricultural Research and Development, c/Berreaga 1, E-48160 Derio (Spain); Becerril, Jose M. [Department of Plant Biology and Ecology, University of the Basque Country, P.O. Box 644, E-48080 Bilbao (Spain); Garbisu, Carlos [NEIKER-tecnalia, Basque Institute of Agricultural Research and Development, c/Berreaga 1, E-48160 Derio (Spain)], E-mail: cgarbisu@neiker.net

    2008-03-15

    A hydroponic screening method was used to identify high biomass crop plants with the ability to accumulate metals. Highest values of shoot accumulation were found in maize cv. Ranchero, rapeseed cv. Karat, and cardoon cv. Peralta for Pb (18 753 mg kg{sup -1}), Zn (10 916 mg kg{sup -1}), and Cd (242 mg kg{sup -1}), respectively. Subsequently, we tested the potential of these three cultivars for the phytoextraction of a metal spiked compost, finding out that, in cardoon and maize plants, increasing Zn and Cd concentrations led to lower values of root and shoot DW. By contrast, rapeseed shoot growth was not significantly affected by Cd concentration. Finally, a metal polluted soil was used to check these cultivars' phytoextraction capacity. Although the soil was phytotoxic enough to prevent the growth of cardoon and rapeseed plants, maize plants phytoextracted 3.7 mg Zn pot{sup -1}. We concluded that the phytoextraction performance of cultivars varies depending on the screening method used. - The phytoextraction performance of cultivars varies significantly depending on the screening method used.

  13. Effectors as Tools in Disease Resistance Breeding Against Biotrophic, Hemibiotrophic, and Necrotrophic Plant Pathogens

    NARCIS (Netherlands)

    Vleeshouwers, V.G.A.A.; Oliver, R.P.

    2014-01-01

    One of most important challenges in plant breeding is improving resistance to the plethora of pathogens that threaten our crops. The ever-growing world population, changing pathogen populations, and fungicide resistance issues have increased the urgency of this task. In addition to a vital inflow of

  14. Not all GMOs are crop plants: non-plant GMO applications in agriculture.

    Science.gov (United States)

    Hokanson, K E; Dawson, W O; Handler, A M; Schetelig, M F; St Leger, R J

    2014-12-01

    Since tools of modern biotechnology have become available, the most commonly applied and often discussed genetically modified organisms are genetically modified crop plants, although genetic engineering is also being used successfully in organisms other than plants, including bacteria, fungi, insects, and viruses. Many of these organisms, as with crop plants, are being engineered for applications in agriculture, to control plant insect pests or diseases. This paper reviews the genetically modified non-plant organisms that have been the subject of permit approvals for environmental release by the United States Department of Agriculture/Animal and Plant Health Inspection Service since the US began regulating genetically modified organisms. This is an indication of the breadth and progress of research in the area of non-plant genetically modified organisms. This review includes three examples of promising research on non-plant genetically modified organisms for application in agriculture: (1) insects for insect pest control using improved vector systems; (2) fungal pathogens of insects to control insect pests; and (3) virus for use as transient-expression vectors for disease control in plants.

  15. Understanding and engineering beneficial plant-microbe interactions: plant growth promotion in energy crops.

    Science.gov (United States)

    Farrar, Kerrie; Bryant, David; Cope-Selby, Naomi

    2014-12-01

    Plant production systems globally must be optimized to produce stable high yields from limited land under changing and variable climates. Demands for food, animal feed, and feedstocks for bioenergy and biorefining applications, are increasing with population growth, urbanization and affluence. Low-input, sustainable, alternatives to petrochemical-derived fertilizers and pesticides are required to reduce input costs and maintain or increase yields, with potential biological solutions having an important role to play. In contrast to crops that have been bred for food, many bioenergy crops are largely undomesticated, and so there is an opportunity to harness beneficial plant-microbe relationships which may have been inadvertently lost through intensive crop breeding. Plant-microbe interactions span a wide range of relationships in which one or both of the organisms may have a beneficial, neutral or negative effect on the other partner. A relatively small number of beneficial plant-microbe interactions are well understood and already exploited; however, others remain understudied and represent an untapped reservoir for optimizing plant production. There may be near-term applications for bacterial strains as microbial biopesticides and biofertilizers to increase biomass yield from energy crops grown on land unsuitable for food production. Longer term aims involve the design of synthetic genetic circuits within and between the host and microbes to optimize plant production. A highly exciting prospect is that endosymbionts comprise a unique resource of reduced complexity microbial genomes with adaptive traits of great interest for a wide variety of applications. © 2014 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  16. High-throughput phenotyping of plant resistance to aphids by automated video tracking

    NARCIS (Netherlands)

    Kloth, K.J.; Broeke, ten C.J.M.; Thoen, H.P.M.; Hanhart-van den Brink, M.; Wiegers, G.L.; Krips, O.E.; Noldus, L.P.J.J.; Dicke, M.; Jongsma, M.A.

    2015-01-01

    Background: Piercing-sucking insects are major vectors of plant viruses causing significant yield losses in crops.Functional genomics of plant resistance to these insects would greatly benefit from the availability of highthroughput, quantitative phenotyping methods. Results: We have developed an

  17. Studies on the effects of application of different foliar fertilizer materials, crop residue and inter cropping on Banana plants

    International Nuclear Information System (INIS)

    Hassan, Yusuf Munim

    1996-01-01

    Five separate experiments were conducted at university of Khartoum demonstration farm during 1993 to 1995 under both orchard and nursery conditions to evaluate the effect of foliar application of different fertilizers, use of crop residue and intercropping on banana (dwarf cavendish). In the first experiment, the effects of foliar application of different concentrations of potassium solution (38%) were studied. The results indicated that application of all concentrations resulted in greater increases in overall growth parameters, higher leaf-N, P, K, Ca, Mg, Mn, Fe, Zn and Cu contents, higher values of yield and yield components , finger length of both plant crop and the first ratoon crop and reduction of time from planting to flowering and from flowering to harvesting of both plant crop and the first crop compared to the control. In the second experiment, the effects of three different foliar fertilizers, namely, compound cryst, fetrilon comb-2 and x-garden were investigated. The results revealed that all fertilizers gave greater values of all growth parameters, higher leaf-N, P, K, Ca, Mg, Mn, Fe, Zn and Cu contents, higher values of yield and yield components , finger length of both plant crop and the first ratoon crop and reduction of time from planting to flowering and from flowering to harvesting of both plant crop and the first crop compared to the control. In the third experiment, the effect of four different fertilizer materials containing different combinations of NPK on growth parameters and nutrient elements contents of leaves of banana suckers grown under nursery conditions was evaluated. The results revealed that all fertilizer materials gave greater increases of growth parameters over the control as well as higher leaf-N, P, K, Ca, Mg, Mn, Fe, Zn and Cu contents. In the fourth experiment, the effect of different concentrations of N 19 , P 19 , K 19 fertilizers on growth characteristics and nutrient elements contents of leaves of banana suckers was

  18. Biochar potential in intensive cultivation of Capsicum annuum L. (sweet pepper): crop yield and plant protection.

    Science.gov (United States)

    Kumar, Abhay; Elad, Yigal; Tsechansky, Ludmila; Abrol, Vikas; Lew, Beni; Offenbach, Rivka; Graber, Ellen R

    2018-01-01

    The influence of various biochars on crop yield and disease resistance of Capsicum annuum L. (sweet pepper) under modern, high input, intensive net house cultivation was tested over the course of 2011-2014 in the Arava desert region of Israel. A pot experiment with Lactuca sativa L. (lettuce) grown in the absence of fertilizer employed the 3-year-old field trial soils to determine if biochar treatments contributed to soil intrinsic fertility. Biochar amendments resulted in a significant increase in the number and weight of pepper fruits over 3 years. Concomitant with the increased yield, biochar significantly decreased the severity of powdery mildew (Leveillula taurica) disease and broad mite (Polyphagotarsonemus latus) pest infestation. Biochar additions resulted in increased soil organic matter but did not influence the pH, electrical conductivity or soil or plant mineral nutrients. Intrinsic fertility experiments with lettuce showed that two of the four biochar-treated field soils had significant positive impacts on lettuce fresh weight and total chlorophyll, carotenoid and anthocyanin contents. Biochar-based soil management can enhance the functioning of intensive, commercial, net house production of peppers under the tested conditions, resulting in increased crop yield and plant resistance to disease over several years. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  19. Cover crops in mixtures do not use water differently than single-species plantings

    Science.gov (United States)

    Some recent statements have been made about the benefits of growing cover crops in mixtures as compared with single-species plantings of cover crops. One of those stated benefits is greatly reduced water use by cover crops grown in mixtures. The objectives of this study were to characterize soil wat...

  20. The Impact of Volunteer Corn on Crop Yields and Insect Resistance Management Strategies

    Directory of Open Access Journals (Sweden)

    Paul T. Marquardt

    2013-06-01

    Full Text Available Volunteer corn (VC has reemerged as a problematic weed in corn/soybean rotational cropping systems. This reemergence and increasing prevalence of volunteer corn has been correlated to an increased adoption of herbicide-resistant (HR corn hybrids and the adoption of conservation tillage. Since the introduction of HR crops, control options, weed/crop competition, and other concerns (i.e., insect resistance management of Bt traits have increased the amount of attention that volunteer corn is receiving. The objective of this review is to discuss what is known about VC prior to and after the introduction of HR crops, and to discuss new information about this important weed.

  1. Limited fitness advantages of crop-weed hybrid progeny containing insect-resistant transgenes (Bt/CpTI in transgenic rice field.

    Directory of Open Access Journals (Sweden)

    Xiao Yang

    Full Text Available BACKGROUND: The spread of insect-resistance transgenes from genetically engineered (GE rice to its coexisting weedy rice (O. sativa f. spontanea populations via gene flow creates a major concern for commercial GE rice cultivation. Transgene flow to weedy rice seems unavoidable. Therefore, characterization of potential fitness effect brought by the transgenes is essential to assess environmental consequences caused by crop-weed transgene flow. METHODOLOGY/PRINCIPAL FINDINGS: Field performance of fitness-related traits was assessed in advanced hybrid progeny of F(4 generation derived from a cross between an insect-resistant transgenic (Bt/CpTI rice line and a weedy strain. The performance of transgene-positive hybrid progeny was compared with the transgene-negative progeny and weedy parent in pure and mixed planting of transgenic and nontransgenic plants under environmental conditions with natural vs. low insect pressure. Results showed that under natural insect pressure the insect-resistant transgenes could effectively suppress target insects and bring significantly increased fitness to transgenic plants in pure planting, compared with nontransgenic plants (including weedy parent. In contrast, no significant differences in fitness were detected under low insect pressure. However, such increase in fitness was not detected in the mixed planting of transgenic and nontransgenic plants due to significantly reduced insect pressure. CONCLUSIONS/SIGNIFICANCE: Insect-resistance transgenes may have limited fitness advantages to hybrid progeny resulted from crop-weed transgene flow owning to the significantly reduced ambient target insect pressure when an insect-resistant GE crop is grown. Given that the extensive cultivation of an insect-resistant GE crop will ultimately reduce the target insect pressure, the rapid spread of insect-resistance transgenes in weedy populations in commercial GE crop fields may be not likely to happen.

  2. Limited fitness advantages of crop-weed hybrid progeny containing insect-resistant transgenes (Bt/CpTI) in transgenic rice field.

    Science.gov (United States)

    Yang, Xiao; Wang, Feng; Su, Jun; Lu, Bao-Rong

    2012-01-01

    The spread of insect-resistance transgenes from genetically engineered (GE) rice to its coexisting weedy rice (O. sativa f. spontanea) populations via gene flow creates a major concern for commercial GE rice cultivation. Transgene flow to weedy rice seems unavoidable. Therefore, characterization of potential fitness effect brought by the transgenes is essential to assess environmental consequences caused by crop-weed transgene flow. Field performance of fitness-related traits was assessed in advanced hybrid progeny of F(4) generation derived from a cross between an insect-resistant transgenic (Bt/CpTI) rice line and a weedy strain. The performance of transgene-positive hybrid progeny was compared with the transgene-negative progeny and weedy parent in pure and mixed planting of transgenic and nontransgenic plants under environmental conditions with natural vs. low insect pressure. Results showed that under natural insect pressure the insect-resistant transgenes could effectively suppress target insects and bring significantly increased fitness to transgenic plants in pure planting, compared with nontransgenic plants (including weedy parent). In contrast, no significant differences in fitness were detected under low insect pressure. However, such increase in fitness was not detected in the mixed planting of transgenic and nontransgenic plants due to significantly reduced insect pressure. Insect-resistance transgenes may have limited fitness advantages to hybrid progeny resulted from crop-weed transgene flow owning to the significantly reduced ambient target insect pressure when an insect-resistant GE crop is grown. Given that the extensive cultivation of an insect-resistant GE crop will ultimately reduce the target insect pressure, the rapid spread of insect-resistance transgenes in weedy populations in commercial GE crop fields may be not likely to happen.

  3. Perspectives on transgenic, herbicide-resistant crops in the United States almost 20 years after introduction.

    Science.gov (United States)

    Duke, Stephen O

    2015-05-01

    Herbicide-resistant crops have had a profound impact on weed management. Most of the impact has been by glyphosate-resistant maize, cotton, soybean and canola. Significant economic savings, yield increases and more efficacious and simplified weed management have resulted in widespread adoption of the technology. Initially, glyphosate-resistant crops enabled significantly reduced tillage and reduced the environmental impact of weed management. Continuous use of glyphosate with glyphosate-resistant crops over broad areas facilitated the evolution of glyphosate-resistant weeds, which have resulted in increases in the use of tillage and other herbicides with glyphosate, reducing some of the initial environmental benefits of glyphosate-resistant crops. Transgenic crops with resistance to auxinic herbicides, as well as to herbicides that inhibit acetolactate synthase, acetyl-CoA carboxylase and hydroxyphenylpyruvate dioxygenase, stacked with glyphosate and/or glufosinate resistance, will become available in the next few years. These technologies will provide additional weed management options for farmers, but will not have all of the positive effects (reduced cost, simplified weed management, lowered environmental impact and reduced tillage) that glyphosate-resistant crops had initially. In the more distant future, other herbicide-resistant crops (including non-transgenic ones), herbicides with new modes of action and technologies that are currently in their infancy (e.g. bioherbicides, sprayable herbicidal RNAi and/or robotic weeding) may affect the role of transgenic, herbicide-resistant crops in weed management. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  4. Neonicotinoid insecticides alter induced defenses and increase susceptibility to spider mites in distantly related crop plants.

    Directory of Open Access Journals (Sweden)

    Adrianna Szczepaniec

    Full Text Available Chemical suppression of arthropod herbivores is the most common approach to plant protection. Insecticides, however, can cause unintended, adverse consequences for non-target organisms. Previous studies focused on the effects of pesticides on target and non-target pests, predatory arthropods, and concomitant ecological disruptions. Little research, however, has focused on the direct effects of insecticides on plants. Here we demonstrate that applications of neonicotinoid insecticides, one of the most important insecticide classes worldwide, suppress expression of important plant defense genes, alter levels of phytohormones involved in plant defense, and decrease plant resistance to unsusceptible herbivores, spider mites Tetranychus urticae (Acari: Tetranychidae, in multiple, distantly related crop plants.Using cotton (Gossypium hirsutum, corn (Zea mays and tomato (Solanum lycopersicum plants, we show that transcription of phenylalanine ammonia lyase, coenzyme A ligase, trypsin protease inhibitor and chitinase are suppressed and concentrations of the phytohormone OPDA and salicylic acid were altered by neonicotinoid insecticides. Consequently, the population growth of spider mites increased from 30% to over 100% on neonicotinoid-treated plants in the greenhouse and by nearly 200% in the field experiment.Our findings are important because applications of neonicotinoid insecticides have been associated with outbreaks of spider mites in several unrelated plant species. More importantly, this is the first study to document insecticide-mediated disruption of plant defenses and link it to increased population growth of a non-target herbivore. This study adds to growing evidence that bioactive agrochemicals can have unanticipated ecological effects and suggests that the direct effects of insecticides on plant defenses should be considered when the ecological costs of insecticides are evaluated.

  5. Neonicotinoid Insecticides Alter Induced Defenses and Increase Susceptibility to Spider Mites in Distantly Related Crop Plants

    Science.gov (United States)

    Szczepaniec, Adrianna; Raupp, Michael J.; Parker, Roy D.; Kerns, David; Eubanks, Micky D.

    2013-01-01

    Background Chemical suppression of arthropod herbivores is the most common approach to plant protection. Insecticides, however, can cause unintended, adverse consequences for non-target organisms. Previous studies focused on the effects of pesticides on target and non-target pests, predatory arthropods, and concomitant ecological disruptions. Little research, however, has focused on the direct effects of insecticides on plants. Here we demonstrate that applications of neonicotinoid insecticides, one of the most important insecticide classes worldwide, suppress expression of important plant defense genes, alter levels of phytohormones involved in plant defense, and decrease plant resistance to unsusceptible herbivores, spider mites Tetranychus urticae (Acari: Tetranychidae), in multiple, distantly related crop plants. Methodology/Principal Findings Using cotton (Gossypium hirsutum), corn (Zea mays) and tomato (Solanum lycopersicum) plants, we show that transcription of phenylalanine amonia lyase, coenzyme A ligase, trypsin protease inhibitor and chitinase are suppressed and concentrations of the phytohormone OPDA and salicylic acid were altered by neonicotinoid insecticides. Consequently, the population growth of spider mites increased from 30% to over 100% on neonicotinoid-treated plants in the greenhouse and by nearly 200% in the field experiment. Conclusions/Significance Our findings are important because applications of neonicotinoid insecticides have been associated with outbreaks of spider mites in several unrelated plant species. More importantly, this is the first study to document insecticide-mediated disruption of plant defenses and link it to increased population growth of a non-target herbivore. This study adds to growing evidence that bioactive agrochemicals can have unanticipated ecological effects and suggests that the direct effects of insecticides on plant defenses should be considered when the ecological costs of insecticides are evaluated. PMID

  6. Biotechnological approaches to control the crop pathogen Fusarium and development of nanotechnology-based diagnostic methods for detection of plant diseases.

    OpenAIRE

    Botella, José Ramón

    2014-01-01

    The plant fungal pathogen Fusarium is the causal agent of ‘Fusarium wilt’ and results in large losses on a wide range of crops including vegetables, flowers, trees and field crops. Control methods for Fusarium wilt are very limited. Crop rotations are ineffective because F. oxysporum has such a large host range and is able to survive in the soil for long periods of time and genetic resistance is very scarce or on-existent in many crops. I will describe the development of two biotechnological ...

  7. Crops with target-site herbicide resistance for Orobanche and Striga control.

    Science.gov (United States)

    Gressel, Jonathan

    2009-05-01

    It is necessary to control root parasitic weeds before or as they attach to the crop. This can only be easily achieved chemically with herbicides that are systemic, or with herbicides that are active in soil. Long-term control can only be attained if the crops do not metabolise the herbicide, i.e. have target-site resistance. Such target-site resistances have allowed foliar applications of herbicides inhibiting enol-pyruvylshikimate phosphate synthase (EPSPS) (glyphosate), acetolactate synthase (ALS) (e.g. chlorsulfuron, imazapyr) and dihydropteroate synthase (asulam) for Orobanche control in experimental conditions with various crops. Large-scale use of imazapyr as a seed dressing of imidazolinone-resistant maize has been commercialised for Striga control. Crops with two target-site resistances will be more resilient to the evolution of resistance in the parasite, if well managed.

  8. Tolerance: the forgotten child of plant resistance

    Directory of Open Access Journals (Sweden)

    Robert K.D. Peterson

    2017-10-01

    Full Text Available Plant resistance against insect herbivory has greatly focused on antibiosis, whereby the plant has a deleterious effect on the herbivore, and antixenosis, whereby the plant is able to direct the herbivore away from it. Although these two types of resistance may reduce injury and yield loss, they can produce selection pressures on insect herbivores that lead to pest resistance. Tolerance, on the other hand, is a more sustainable pest management strategy because it involves only a plant response and therefore does not cause evolution of resistance in target pest populations. Despite its attractive attributes, tolerance has been poorly studied and understood. In this critical, interpretive review, we discuss tolerance to insect herbivory and the biological and socioeconomic factors that have limited its use in plant resistance and integrated pest management. First, tolerance is difficult to identify, and the mechanisms conferring it are poorly understood. Second, the genetics of tolerance are mostly unknown. Third, several obstacles hinder the establishment of high-throughput phenotyping methods for large-scale screening of tolerance. Fourth, tolerance has received little attention from entomologists because, for most, their primary interest, research training, and funding opportunities are in mechanisms which affect pest biology, not plant biology. Fifth, the efforts of plant resistance are directed at controlling pest populations rather than managing plant stress. We conclude this paper by discussing future research and development activities.

  9. Metal resistance sequences and transgenic plants

    Science.gov (United States)

    Meagher, Richard Brian; Summers, Anne O.; Rugh, Clayton L.

    1999-10-12

    The present invention provides nucleic acid sequences encoding a metal ion resistance protein, which are expressible in plant cells. The metal resistance protein provides for the enzymatic reduction of metal ions including but not limited to divalent Cu, divalent mercury, trivalent gold, divalent cadmium, lead ions and monovalent silver ions. Transgenic plants which express these coding sequences exhibit increased resistance to metal ions in the environment as compared with plants which have not been so genetically modified. Transgenic plants with improved resistance to organometals including alkylmercury compounds, among others, are provided by the further inclusion of plant-expressible organometal lyase coding sequences, as specifically exemplified by the plant-expressible merB coding sequence. Furthermore, these transgenic plants which have been genetically modified to express the metal resistance coding sequences of the present invention can participate in the bioremediation of metal contamination via the enzymatic reduction of metal ions. Transgenic plants resistant to organometals can further mediate remediation of organic metal compounds, for example, alkylmetal compounds including but not limited to methyl mercury, methyl lead compounds, methyl cadmium and methyl arsenic compounds, in the environment by causing the freeing of mercuric or other metal ions and the reduction of the ionic mercury or other metal ions to the less toxic elemental mercury or other metals.

  10. New ways enhancing the vital activity of plants in order to increase crop yields and to suppress radionuclide accumulation

    International Nuclear Information System (INIS)

    Goncharova, N. V; Zebrakova, I. V.; Matsko, V. P.; Kislushko, P. M.

    1994-01-01

    After Chernobyl nuclear accident it has become very important to seek new ways of enhancing the vital activity of plants in order to increase crop yields and to suppress radionuclide accumulation. It is found that by optimizing the vital activity processes in plants, is possible to reduce radionuclide uptake. A great number of biologically active compounds have been tested, which increased the disease resistance of plants and simultaneously activated the physiological and biochemical processes that control the transport of micro- and macroelements (radionuclide included) and their 'soil-root-stem-leaf' redistribution. (author)

  11. Salicylic acid-induced glutathione status in tomato crop and resistance to root-knot nematode, Meloidogyne incognita (Kofoid & White Chitwood

    Directory of Open Access Journals (Sweden)

    Hari C. Meher

    2011-10-01

    Full Text Available Salicylic acid-(SA is a plant defense stimulator. Exogenous application of SA might influence the status of glutathione-(GSH. GSH activates and SA alters the expression of defense genes to modulate plant resistance against pathogens. The fate of GSH in a crop following SA treatment is largely unknown. The SA-induced profiles of free reduced-, free oxidized-(GSSG and protein bound-(PSSG glutathione in tomato crop following foliar treatment of transplant at 5.0-10.0 μg mL–1 were measured by liquid chromatography. Resistance to root-knot nematode, Meloidogyne incognita damaging tomato and crop performance were also evaluated. SA treatment at 5.0-10.0 μg mL–1 to tomato transplants increased GSH, GSSG and PSSG in plant leaf and root, more so in leaf, during crop growth and development. As the fruits ripened, GSH and PSSG increased and GSSG declined. SA reduced the root infection by M. incognita, nematode reproduction and thus, improved the resistance of tomato var. Pusa Ruby, but reduced crop growth and redox status. SA at 5.0 μg mL–1 improved yield and fruit quality. The study firstly linked SA with activation of glutathione metabolism and provided an additional dimension to the mechanism of induced resistance against obligate nematode pathogen. SA increased glutathione status in tomato crop, imparted resistance against M. incognita, augmented crop yield and functional food quality. SA can be applied at 5.0 μg mL–1 for metabolic engineering of tomato at transplanting to combine host-plant resistance and health benefits in formulating a strategic nematode management decision.

  12. The biochar effect: plant resistance to biotic stresses

    Directory of Open Access Journals (Sweden)

    YIGAL ELAD

    2012-01-01

    Full Text Available Biochar (charcoal is the solid co-product of pyrolysis, the thermal degradation of biomass in the absence of oxygen. Pyrolysis also yields gaseous and liquid biofuel products. There is a growing interest worldwide in the pyrolysis platform, for at least four reasons: (i pyrolysis can be a source of renewable biofuels; (ii many biomass waste materials can be treated by pyrolysis and thus converted into a fuel resource; (iii long-term sequestration of carbon dioxide which originated in the atmosphere may result from adding biochar to soil; and (iv biochar soil amendment contributes to improved soil fertility and crop productivity. Currently, however, very little biochar is utilized in agriculture, in part because its agronomic value in terms of crop response and soil health benefits have yet to be quantified, and because the mechanisms by which it improves soil fertility are poorly understood. The positive effects of biochar on crop productivity under conditions of extensive agriculture are frequently attributed to direct effects of biochar-supplied nutrients and to several other indirect effects, including increased water and nutrient retention, improvements in soil pH, increased soil cation exchange capacity, effects on P and S transformations and turnover, neutralization of phytotoxic compounds in the soil, improved soil physical properties, promotion of mycorrhizal fungi, and alteration of soil microbial populations and functions. Yet, the biochar effect is also evident under conditions of intensive production where many of these parameters are not limited. Biochar addition to soil alters microbial populations in the rhizosphere, albeit via mechanisms not yet understood, and may cause a shift towards beneficial microorganism populations that promote plant growth and resistance to biotic stresses. In addition to some scant evidence for biochar-induced plant protection against soilborne diseases, the induction of systemic resistance towards

  13. Plant breeding for resistance to insect pests: Considerations about the use of induced mutations

    International Nuclear Information System (INIS)

    1978-01-01

    The Panel was intended to stimulate proposals on specific plant breeding objectives, for immediate and long term solution. Nine papers considered the host plant resistance to particular insect pests in a variety of cases. The desirability of achieving some measure of pest control via the development of disease-resistant mutants was discussed. In its conclusions, the Panel stressed the need to consider host plant resistance as one of the primary lines of defense in all pest management programmes. Consequently, resistance to insects was recommended to become an integral part of plant breeding programmes. Preference might need to be given to developing insect resistance in those crop plants for which practical control is lacking or where current methods of pest control present critical environmental hazards. The roles of the IAEA and FAO in such projects is outlined. Guidelines and recommendations on mutation breeding for resistance to insects are given in an appendix

  14. Infection processes of xylem-colonizing pathogenic bacteria: possible explanations for the scarcity of qualitative disease resistance genes against them in crops.

    Science.gov (United States)

    Bae, Chungyun; Han, Sang Wook; Song, Yu-Rim; Kim, Bo-Young; Lee, Hyung-Jin; Lee, Je-Min; Yeam, Inhwa; Heu, Sunggi; Oh, Chang-Sik

    2015-07-01

    Disease resistance against xylem-colonizing pathogenic bacteria in crops. Plant pathogenic bacteria cause destructive diseases in many commercially important crops. Among these bacteria, eight pathogens, Ralstonia solanacearum, Xanthomonas oryzae pv. oryzae, X. campestris pv. campestris, Erwinia amylovora, Pantoea stewartii subsp. stewartii, Clavibacter michiganensis subsp. michiganensis, Pseudomonas syringae pv. actinidiae, and Xylella fastidiosa, infect their host plants through different infection sites and paths and eventually colonize the xylem tissues of their host plants, resulting in wilting symptoms by blocking water flow or necrosis of xylem tissues. Noticeably, only a relatively small number of resistant cultivars in major crops against these vascular bacterial pathogens except X. oryzae pv. oryzae have been found or generated so far, although these pathogens threaten productivity of major crops. In this review, we summarize the lifestyles of major xylem-colonizing bacterial pathogens and then discuss the progress of current research on disease resistance controlled by qualitative disease resistance genes or quantitative trait loci against them. Finally, we propose infection processes of xylem-colonizing bacterial pathogens as one of possible reasons for why so few qualitative disease resistance genes against these pathogens have been developed or identified so far in crops.

  15. Pathways of invasive plant spread to Alaska: III. contaminants in crop and grass seed

    Science.gov (United States)

    Invasive plants disperse to new areas via numerous pathways. Study of these pathways helps to focus limited budgets for prevention and early detection. This study examined seed contaminants in imported crop and grass seed as pathway for plant dispersal to Alaska. Crop and grass seed were purchased f...

  16. Does crop rotational diversity increase soil microbial resistance and resilience to drought and flooding?

    Science.gov (United States)

    Schnecker, Jörg; Calderon, Francisco; Cavigelli, Michel; Lehman, Michael; Tiemann, Lisa; Grandy, Stuart

    2017-04-01

    Future climate scenarios indicate more frequent and stronger extreme weather events. This includes more severe droughts but also an increase in heavy rain events and flooding. Agricultural systems are of special interest in this context because of their role in food security but also because of their potentially changing role in global carbon and nutrient cycling under these extreme conditions. Plant diversification strategies like more complex crop rotations which support more diverse soil microbial communities with higher functional redundancy might be more resistant to drought and flooding and could help to reduce impacts on microbial carbon and nutrient cycling. To test how crop diversification affects the response of soil microbial processes to drought and flooding and reoccurring drought and flooding, we manipulated water regimes in lab incubation experiments using soils from four long term rotation experiments across the USA, including a low (one or two crops) vs. high (>3 crops) diversity rotations at each site. The sites range from low precipitation (Colorado), over intermediate precipitation (Michigan and South Dakota) to high precipitation in Maryland. Replicate sets of samples were either allowed to dry out, were gradually flooded or kept at a constant water content (control). We monitored CO2 production during five stress cycles. Additionally, we determined microbial biomass, enzyme activities and N pools during the first and last stress cycle in soils from the precipitation extremes. After a total incubation length of 165 days and five stress cycles only the soils from short rotations in Maryland and South Dakota that had been subjected to reoccurring drought showed significantly less cumulative CO2 loss compared to their respective controls. All the other sites and rotation length did not significantly differ from control when subjected to reoccurring drought or flooding. A Principal component analysis using all measured parameters of Colorado and

  17. Induced disease resistance signaling in plants

    NARCIS (Netherlands)

    Verhagen, B.W.M.; Loon, L.C. van; Pieterse, C.M.J.

    2006-01-01

    To protect themselves from disease, plants have evolved sophisticated inducible defense mechanisms in which the signal molecules salicylic acid, jasmonic acid and ethylene often play crucial roles. Elucidation of signaling pathways controlling induced disease resistance is a major objective in

  18. Energy crops for biogas plants. Bavaria; Energiepflanzen fuer Biogasanlagen. Bayern

    Energy Technology Data Exchange (ETDEWEB)

    Aigner, A.; Biertuempel, A.; Conrad, M. (and others)

    2012-08-15

    For agriculturists in Bavaria (Federal Republic of Germany), the brochure under consideration provides recommendations on alternative crop rotation systems. With the help of these alternative cultivation systems, crop rotation with high yields in combination with high diversity, diversification and sustainability can be realized. Subsequently to the presentation of energy crops for the production of biogas, recommendations for the design of crop rotation are given. Other chapters of this booklet deal with ensilage and gas yields as well as the economics of energy crop cultivation.

  19. Are stomatal responses the key to understanding the cost of fungal disease resistance in plants?

    Science.gov (United States)

    Withers, Catherine M; Gay, Alan P; Mur, Luis A J

    2011-07-01

    Preventing disease in cereal crops is important for maintaining productivity and as the availability and efficacy of chemical control becomes reduced the emphasis on breeding for disease resistance increases. However, there is evidence that disease resistance may be physiologically costly to the plant and we ask if understanding stomatal responses to fungal attack is the key to minimising reductions in growth associated with disease resistance. Copyright © 2011 Society of Chemical Industry.

  20. Notification: Evaluation of EPA's Management of Resistance Issues Related to Herbicide Tolerant Genetically Engineered Crops

    Science.gov (United States)

    Project #OPE-FY16-0023, March 25, 2016. The EPA OIG plans to begin preliminary research to assess the EPA's management and oversight of resistance issues related to herbicide tolerant genetically engineered crops.

  1. Omics Approaches for the Engineering of Pathogen Resistant Plants.

    Science.gov (United States)

    Gomez-Casati, Diego F; Pagani, María A; Busi, María V; Bhadauria, Vijai

    2016-01-01

    The attack of different pathogens, such as bacteria, fungi and viruses has a negative impact on crop production. In counter such attacks, plants have developed different strategies involving the modification of gene expression, activation of several metabolic pathways and post-translational modification of proteins, which culminate into the accumulation of primary and secondary metabolites implicated in plant defense responses. The recent advancement in omics techniques allows the increase coverage of plants transcriptomes, proteomes and metabolomes during pathogen attack, and the modulation of the response after the infection. Omics techniques also allow us to learn more about the biological cycle of the pathogens in addition to the identification of novel virulence factors in pathogens and their host targets. Both approaches become important to decipher the mechanism underlying pathogen attacks and to develop strategies for improving disease-resistant plants. In this review, we summarize some of the contribution of genomics, transcriptomics, proteomics, metabolomics and metallomics in devising the strategies to obtain plants with increased resistance to pathogens. These approaches constitute important research tools in the development of new technologies for the protection against diseases and increase plant production.

  2. Association mapping of plant resistance to insects

    NARCIS (Netherlands)

    Kloth, K.J.; Thoen, H.P.M.; Bouwmeester, H.J.; Jongsma, M.A.; Dicke, M.

    2012-01-01

    Association mapping is rapidly becoming an important method to explore the genetic architecture of complex traits in plants and offers unique opportunities for studying resistance to insect herbivores. Recent studies indicate that there is a trade-off between resistance against generalist and

  3. Quantitative Resistance to Biotrophic Filamentous Plant Pathogens

    NARCIS (Netherlands)

    Niks, R.E.; Qi, Xiaoquan; Marcel, T.C.

    2015-01-01

    Quantitative resistance (QR) refers to a resistance that is phenotypically incomplete and is based on the joined effect of several genes, each contributing quantitatively to the level of plant defense. Often, QR remains durably effective, which is the primary driver behind the interest in it. The

  4. Controversy Associated With the Common Component of Most Transgenic Plants – Kanamycin Resistance Marker Gene

    Directory of Open Access Journals (Sweden)

    Srećko Jelenić

    2003-01-01

    Full Text Available Plant genetic engineering is a powerful tool for producing crops resistant to pests, diseases and abiotic stress or crops with improved nutritional value or better quality products. Currently over 70 genetically modified (GM crops have been approved for use in different countries. These cover a wide range of plant species with significant number of different modified traits. However, beside the technology used for their improvement, the common component of most GM crops is the neomycin phosphotransferase II gene (nptII, which confers resistance to the antibiotics kanamycin and neomycin. The nptII gene is present in GM crops as a marker gene to select transformed plant cells during the first steps of the transformation process. The use of antibiotic-resistance genes is subject to controversy and intense debate, because of the likelihood that clinical therapy could be compromised due to inactivation of the oral dose of the antibiotic from consumption of food derived from the transgenic plant, and because of the risk of gene transfer from plants to gut and soil microorganisms or to consumer’s cells. The present article discusses these possibilities in the light of current scientific knowledge.

  5. Evolution of Resistance by Helicoverpa zea (Lepidoptera: Noctuidae) Infesting Insecticidal Crops in the Southern United States

    Science.gov (United States)

    Onstad, David; Crain, Philip; Crespo, Andre; Hutchison, William; Buntin, David; Porter, Pat; Catchot, Angus; Cook, Don; Pilcher, Clint; Flexner, Lindsey; Higgins, Laura

    2016-01-01

    We created a deterministic, frequency-based model of the evolution of resistance by corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), to insecticidal traits expressed in crops planted in the heterogeneous landscapes of the southern United States. The model accounts for four generations of selection by insecticidal traits each year. We used the model results to investigate the influence of three factors on insect resistance management (IRM): 1) how does adding a third insecticidal trait to both corn and cotton affect durability of the products, 2) how does unstructured corn refuge influence IRM, and 3) how do block refuges (50% compliance) and blended refuges compare with regard to IRM? When Bt cotton expresses the same number of insecticidal traits, Bt corn with three insecticidal traits provides longer durability than Bt corn with two pyramided traits. Blended refuge provides similar durability for corn products compared with the same level of required block refuge when the rate of refuge compliance by farmers is 50%. Results for Mississippi and Texas are similar, but durabilities for corn traits are surprisingly lower in Georgia, where unstructured corn refuge is the highest of the three states, but refuge for Bt cotton is the lowest of the three states. Thus, unstructured corn refuge can be valuable for IRM but its influence is determined by selection for resistance by Bt cotton. PMID:26637533

  6. Complex Interactions between Fungal Avirulence Genes and Their Corresponding Plant Resistance Genes and Consequences for Disease Resistance Management

    Directory of Open Access Journals (Sweden)

    Yohann Petit-Houdenot

    2017-06-01

    Full Text Available During infection, pathogens secrete an arsenal of molecules, collectively called effectors, key elements of pathogenesis which modulate innate immunity of the plant and facilitate infection. Some of these effectors can be recognized directly or indirectly by resistance (R proteins from the plant and are then called avirulence (AVR proteins. This recognition usually triggers defense responses including the hypersensitive response and results in resistance of the plant. R—AVR gene interactions are frequently exploited in the field to control diseases. Recently, the availability of fungal genomes has accelerated the identification of AVR genes in plant pathogenic fungi, including in fungi infecting agronomically important crops. While single AVR genes recognized by their corresponding R gene were identified, more and more complex interactions between AVR and R genes are reported (e.g., AVR genes recognized by several R genes, R genes recognizing several AVR genes in distinct organisms, one AVR gene suppressing recognition of another AVR gene by its corresponding R gene, two cooperating R genes both necessary to recognize an AVR gene. These complex interactions were particularly reported in pathosystems showing a long co-evolution with their host plant but could also result from the way agronomic crops were obtained and improved (e.g., through interspecific hybridization or introgression of resistance genes from wild related species into cultivated crops. In this review, we describe some complex R—AVR interactions between plants and fungi that were recently reported and discuss their implications for AVR gene evolution and R gene management.

  7. Molecular Genetic Approaches for Environmental Stress Tolerant Crop Plants: Progress and Prospects.

    Science.gov (United States)

    Kaur, Ranjeet; Kumar Bhunia, Rupam; Ghosh, Ananta Kumar

    2016-01-01

    Global food security is threatened by the severe environmental conditions that have reduced the worldwide crop yield. Plants possess inherent mechanisms to cope with the initial stress phase but to ensure their survival through harsh climate, the intervention of genetic engineering is desirable. We present a comprehensive review on the progress made in the field of developing environmental stress tolerant crops and the prospects that can be undertaken for achieving it. We review the effects of abiotic and biotic stresses on crop plants, and the use of different molecular genetic approaches to cope with these environmental stresses for establishment of sustainable agriculture. The various strategies employed in different crops have also been discussed. We also summarized the major patents in the field of plant stress tolerance that have been granted in the last five years. On the basis of these analyses, we propose that genetic engineering of crops is the preferred approach over the traditional methods for yielding healthier and viable agriculture in response to the different stressful environments. The wild progenitors of cultivated crop species can prove to be highly potential genetic resources in this regard and can be exploited to produce better crops that are relatively tolerant towards various environmental stresses. Thus, elucidation of genetic loci and deciphering the underlying mechanisms that confer tolerance to plants against stressful conditions followed by its successful introgression into elite, high-yielding crop varieties can be an effective way to engineer the crops for sustainable agriculture.

  8. Energy crops for biogas plants. Brandenburg; Energiepflanzen fuer Biogasanlagen. Brandenburg

    Energy Technology Data Exchange (ETDEWEB)

    Adam, L.; Barthelmes, G.; Biertuempfel, A. (and others)

    2012-06-15

    In the brochure under consideration, the Agency for Renewable Resources (Guelzen-Pruezen, Federal Republic of Germany) reported on recommendations on alternative cropping systems for energy crop rotations in order to achieve high yields in combination with high diversity, risk spreading and sustainability. In particular, the natural site conditions in the Federal State of Brandenburg (Federal Republic of Germany) are determined.

  9. Diverse influence of nanoparticles on plant growth with a particular emphasis on crop plants

    Directory of Open Access Journals (Sweden)

    Anna Milewska-Hendel

    2016-12-01

    Full Text Available The article describes the current knowledge about the impact of nanoparticles on plant development with a particular emphasis on crop plants. Nanotechnology is an intensively developing field of science. This is due to the enormous hopes that have been placed on the achievements of nanotechnology in various areas of life. Increasingly, it has been noted that apart from the future benefits of nanotechnology in our everyday life, nanoparticles (NPs may also have adverse effects that have not been sufficiently explored and understood. Most analyses to date have been focused on the influence of nanomaterials on the physiological processes primarily in animals, humans and bacteria. Although our knowledge about the influence of NPs on the development of plants is considerably smaller, the current views are presented below. Such knowledge is extremely important since NPs can enter the food chain, which may have an influence on human health.

  10. RNA Interference (RNAi) as a Potential Tool for Control of Mycotoxin Contamination in Crop Plants: Concepts and Considerations.

    Science.gov (United States)

    Majumdar, Rajtilak; Rajasekaran, Kanniah; Cary, Jeffrey W

    2017-01-01

    Mycotoxin contamination in food and feed crops is a major concern worldwide. Fungal pathogens of the genera Aspergillus. Fusarium , and Penicillium are a major threat to food and feed crops due to production of mycotoxins such as aflatoxins, 4-deoxynivalenol, patulin, and numerous other toxic secondary metabolites that substantially reduce the value of the crop. While host resistance genes are frequently used to introgress disease resistance into elite germplasm, either through traditional breeding or transgenic approaches, such resistance is often compromised by the evolving pathogen over time. RNAi-based host-induced gene silencing of key genes required by the pathogen for optimal growth, virulence and/or toxin production, can serve as an alternative, pre-harvest approach for disease control. RNAi represents a robust and efficient tool that can be used in a highly targeted, tissue specific manner to combat mycotoxigenic fungi infecting crop plants. Successful transgenic RNAi implementation depends on several factors including (1) designing vectors to produce double-stranded RNAs (dsRNAs) that will generate small interfering RNA (siRNA) species for optimal gene silencing and reduced potential for off-target effects; (2) availability of ample target siRNAs at the infection site; (3) efficient uptake of siRNAs by the fungus; (4) siRNA half-life and (5) amplification of the silencing effect. This review provides a critical and comprehensive evaluation of the published literature on the use of RNAi-based approaches to control mycotoxin contamination in crop plants. It also examines experimental strategies used to better understand the mode of action of RNAi with the aim of eliminating mycotoxin contamination, thereby improving food and feed safety.

  11. A history of plant virology. Mendelian genetics and resistance of plants to viruses.

    Science.gov (United States)

    Pennazio, S; Roggero, P; Conti, M

    2001-10-01

    Virology was borne at the end of the nineteenth century, some years before the re-discovery of the so-called "Mendel's Laws". The rapid development of genetics was helpful to horticulturists and plant pathologists to produce hybrids of important cropping species resistant to several virus diseases. The concepts of Mendelian genetics were applied to plant virology by Francis Oliver Holmes, an American scientist who must be considered a pioneer in several fields of modern plant virology. During the Thirties, Holmes studied in particular the hypersensitive response of solanaceous plants to TMV and discovered the N dominant gene of tobacco hypersensitive to this virus. After the Second World War, the theoretic and practical support given by geneticists assisted plant virologists in better understanding the mechanism of inheritance of the character "resistance". The major problems posed by breeding for plant resistance were detected and critically discussed in several reviews published between the Fifties and the Sixties. These results, together with the discovery of the genetic functions of RNA virus raised interest on the possible relations between viral and plant genes. This fundamental subject saw the entry into the virological scene of molecular genetics, and in 1970 the Russian virologist Joseph Atabekov introduced host specificity to viruses as a central point of plant virology. From the mid 1980s, this point attracted the interest of several virologists, and many results led to several theoretic models of genetic interactions between plant and virus products. In the last fifteen years, the introduction of transgenic plants has given a remarkable contribution to the question of host specificity, which, however, still awaits a general explanation.

  12. Maize plants produce direct resistance elicited by Tetranychus urticae Koch (Acari: Tetranychidae

    Directory of Open Access Journals (Sweden)

    P. D. Paulo

    2017-06-01

    Full Text Available Abstract Plants can be attacked by a wide variety of herbivores. Thus, developing protective mechanisms for resistance against these agents is an advantage for survival and reproduction. Over the course of evolution, many resistance mechanisms against herbivory have been developed by the plants. Induced direct and indirect resistance mechanisms can manifest in plants after herbivore attack. The two-spotted spider mite Tetranychus urticae is not a pest of maize crops (Zea mays, despite being reported infesting plants that may have resistances against this herbivore. We tested the hypothesis that maize plants would be able to induce direct resistance against T. urticae after, evaluating the effect of T. urticae infestation in maize plants on the development and reproduction of conspecifics. We tested induced direct resistance performing infestation and measuring biological parameters upon a second infestation. Maize plants, 40 days after sowing, were divided into two groups: 30 not infested by T. urticae (clean plants clean and, 30 infested by the spider mite. Infestation of maize plants by T. urticae reduced the conspecific female adult survival. However, no change in the survival of immature or reproduction was observed. These results suggest the induction of induced direct resistances in maize by T. urticae. This is first report of direct resistance induction in Z. mays by the two-spotted spider mite T. urticae.

  13. The effect of date of aerial pollution of agricultural plants on 89 Sr content in crops

    International Nuclear Information System (INIS)

    Arkhipov, N.P.; Tevraleva, L.T.

    1979-01-01

    On the basis of the experimental data obtained in different soil-climatic zones of the USSR it is shown that for tentative calculations of the radiostrontium content in farm crop with the aerial source of nuclide delivery the period of time from plant contamination to harvesting can be used. Given are the regression equations relating 89 Sr concentration in corn, wheat and potato crops with the time of crop contamination for six native zones and the characteristics of their accuracy

  14. Pleiotropic effects of herbicide-resistance genes on crop yield: a review.

    Science.gov (United States)

    Darmency, Henri

    2013-08-01

    The rapid adoption of genetically engineered herbicide-resistant crop varieties (HRCVs)-encompassing 83% of all GM crops and nearly 8% of the worldwide arable area-is due to technical efficiency and higher returns. Other herbicide-resistant varieties obtained from genetic resources and mutagenesis have also been successfully released. Although the benefit for weed control is the main criteria for choosing HRCVs, the pleiotropic costs of genes endowing resistance have rarely been investigated in crops. Here the available data of comparisons between isogenic resistant and susceptible varieties are reviewed. Pleiotropic harmful effects on yield are reported in half of the cases, mostly with resistance mechanisms that originate from genetic resources and mutagenesis (atrazine in oilseed rape and millet, trifluralin in millet, imazamox in cotton) rather than genetic engineering (chlorsulfuron and glufosinate in some oilseed rape varieties, glyphosate in soybean). No effect was found for sethoxydim and bromoxynil resistance. Variable minor effects were found for imazamox, chlorsulfuron, glufosinate and glyphosate resistance. The importance of the breeding plan and the genetic background on the emergence of these effects is pointed out. Breeders' efforts to produce better varieties could compensate for the yield loss, which eliminates any possibility of formulating generic conclusions on pleiotropic effects that can be applied to all resistant crops. © 2013 Society of Chemical Industry.

  15. Native root-associated bacteria rescue a plant from a sudden-wilt disease that emerged during continuous cropping

    Science.gov (United States)

    Santhanam, Rakesh; Luu, Van Thi; Weinhold, Arne; Goldberg, Jay; Oh, Youngjoo; Baldwin, Ian T.

    2015-01-01

    Plants maintain microbial associations whose functions remain largely unknown. For the past 15 y, we have planted the annual postfire tobacco Nicotiana attenuata into an experimental field plot in the plant’s native habitat, and for the last 8 y the number of plants dying from a sudden wilt disease has increased, leading to crop failure. Inadvertently we had recapitulated the common agricultural dilemma of pathogen buildup associated with continuous cropping for this native plant. Plants suffered sudden tissue collapse and black roots, symptoms similar to a Fusarium–Alternaria disease complex, recently characterized in a nearby native population and developed into an in vitro pathosystem for N. attenuata. With this in vitro disease system, different protection strategies (fungicide and inoculations with native root-associated bacterial and fungal isolates), together with a biochar soil amendment, were tested further in the field. A field trial with more than 900 plants in two field plots revealed that inoculation with a mixture of native bacterial isolates significantly reduced disease incidence and mortality in the infected field plot without influencing growth, herbivore resistance, or 32 defense and signaling metabolites known to mediate resistance against native herbivores. Tests in a subsequent year revealed that a core consortium of five bacteria was essential for disease reduction. This consortium, but not individual members of the root-associated bacteria community which this plant normally recruits during germination from native seed banks, provides enduring resistance against fungal diseases, demonstrating that native plants develop opportunistic mutualisms with prokaryotes that solve context-dependent ecological problems. PMID:26305938

  16. Camelina as a sustainable oilseed crop: contributions of plant breeding and genetic engineering.

    Science.gov (United States)

    Vollmann, Johann; Eynck, Christina

    2015-04-01

    Camelina is an underutilized Brassicaceae oilseed plant with a considerable agronomic potential for biofuel and vegetable oil production in temperate regions. In contrast to most Brassicaceae, camelina is resistant to alternaria black spot and other diseases and pests. Sequencing of the camelina genome revealed an undifferentiated allohexaploid genome with a comparatively large number of genes and low percentage of repetitive DNA. As there is a close relationship between camelina and the genetic model plant Arabidopsis, this review aims at exploring the potential of translating basic Arabidopsis results into a camelina oilseed crop for food and non-food applications. Recently, Arabidopsis genes for drought resistance or increased photosynthesis and overall productivity have successfully been expressed in camelina. In addition, gene constructs affecting lipid metabolism pathways have been engineered into camelina for synthesizing either long-chain polyunsaturated fatty acids, hydroxy fatty acids or high-oleic oils in particular camelina strains, which is of great interest in human food, industrial or biofuel applications, respectively. These results confirm the potential of camelina to serve as a biotechnology platform in biorefinery applications thus justifying further investment in breeding and genetic research for combining agronomic potential, unique oil quality features and biosafety into an agricultural production system. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Return to Resistance: Breeding Crops to Reduce Pesticide ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    However the colossal, unrecognized failure of modern crops is their extreme susceptiblity to pests and diseases, and the consequent necessity to spray them ... Le CRDI et le Australian Centre for International Agricultural Research, ont conclu un accord en vue d'un nouvel investissement de 25 millions de dollars canadiens ...

  18. Ring spot disease of brassica crops : resistance and epidemiology

    NARCIS (Netherlands)

    Ende, van den J.E.

    1998-01-01

    Ring spot disease of brassica crops is caused by the fungus Mycosphaerella brassicicola . The disease can cause severe qualitative and quantitative losses, depending on the initial inoculum, the environmental conditions during the growing season and the susceptibility

  19. Role of herbicide-resistant crops in integrated weed management

    Science.gov (United States)

    Chemical weed control began with the use of 2,4-D in the mid-1940s. Since then, a wide array of herbicides has been commercialized and that has greatly contributed to increased crop yields. With the introduction of several new, more specific and more effective herbicides, the cost of weed control wi...

  20. Quantification of SO2 effects on physiological processes, plant growth and crop production

    NARCIS (Netherlands)

    Kropff, M.

    1989-01-01

    SO 2 may cause damage on crops and vegetation. This thesis aimes to explain the impact of SO 2 on plant growth and crop production on basis of a quantitative analysis of SO

  1. Impact of crop residues on seed germination of native desert plants ...

    African Journals Online (AJOL)

    Crop residues produce allelochemicals that may inhibit seed germination of many weeds. In this study, I assessed the effect of aqueous extracts of three crop residues (radish, rocket and rhodes) on final germination percentage and germination rate of four desert plants recorded as weeds in the United Arab Emirates farms ...

  2. Application of hordothionins and cecropin B for engineering bacterial disease resistance into plants

    NARCIS (Netherlands)

    Florack, D.

    1994-01-01

    Bacterial diseases can cause a drastic decrease of yield in certain crops. Breeding for bacterial disease resistance therefore is of utmost necessity. Up to now, traditional plant breeding was the only method to reach this goal. Recent developments in genetic engineering technology however

  3. Yeast cell wall extract induces disease resistance against bacterial and fungal pathogens in Arabidopsis thaliana and Brassica crop.

    Directory of Open Access Journals (Sweden)

    Mari Narusaka

    Full Text Available Housaku Monogatari (HM is a plant activator prepared from a yeast cell wall extract. We examined the efficacy of HM application and observed that HM treatment increased the resistance of Arabidopsis thaliana and Brassica rapa leaves to bacterial and fungal infections. HM reduced the severity of bacterial leaf spot and anthracnose on A. thaliana and Brassica crop leaves with protective effects. In addition, gene expression analysis of A. thaliana plants after treatment with HM indicated increased expression of several plant defense-related genes. HM treatment appears to induce early activation of jasmonate/ethylene and late activation of salicylic acid (SA pathways. Analysis using signaling mutants revealed that HM required SA accumulation and SA signaling to facilitate resistance to the bacterial pathogen Pseudomonas syringae pv. maculicola and the fungal pathogen Colletotrichum higginsianum. In addition, HM-induced resistance conferred chitin-independent disease resistance to bacterial pathogens in A. thaliana. These results suggest that HM contains multiple microbe-associated molecular patterns that activate defense responses in plants. These findings suggest that the application of HM is a useful tool that may facilitate new disease control methods.

  4. Novel enabling technologies of gene isolation and plant transformation for improved crop protection

    Energy Technology Data Exchange (ETDEWEB)

    Torok, Tamas

    2013-02-04

    Meeting the needs of agricultural producers requires the continued development of improved transgenic crop protection products. The completed project focused on developing novel enabling technologies of gene discovery and plant transformation to facilitate the generation of such products.

  5. Energy crops for biogas plants. Lower Saxony; Energiepflanzen fuer Biogasanlagen. Niedersachsen

    Energy Technology Data Exchange (ETDEWEB)

    Aurbacher, J.; Benke, M.; Formowitz, B. (and others)

    2012-06-15

    In the brochure under consideration the Agency for Renewable Resources (Guelzow-Pruezen, Federal Republic of Germany) reports on the support of the implementation of different plant cultures in structure of plantations and crop rotation systems of companies under consideration of the Federal State Lower Saxony. The main chapters of this brochure are: Crops for the production of biogas; implementation in plantations; ensilage and biogas yields; economy of the cultivation of energy plants.

  6. Crop coefficient approaches based on fixed estimates of leaf resistance are not appropriate for estimating water use of citrus

    CSIR Research Space (South Africa)

    Taylor

    2015-03-01

    Full Text Available Production and Soil Science, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa e-mail: nicolette.taylor@up.ac.za 2 Citrus Research International, P.O. Box 28, Nelspruit 1200, South Africa 3 CSIR – Natural Resources and the Environment... Crop coefficient approaches based on fixed estimates of leaf resistance are not appropriate for estimating water use of citrus N. J. Taylor 1 · W. Mahohoma1 · J. T. Vahrmeijer2. M. B. Gush3 · R. G. Allen4 · J. G. Annandale1 1 Department of Plant...

  7. Utilization of ionizing radiations and radioisotopes in plant breeding and crop improvement in Arab countries

    International Nuclear Information System (INIS)

    Abo-Hegazi, A.M.T.

    1983-01-01

    A review for research work in the field of utilizing ionizing radiations and radioisotopes in plant breeding and crop improvement conducted in Arab countries has been summerized and discussed in the light of some economic features of the crop or the plant on national or regional (arab) level. Among the 241 articles in the above mentioned fields reviewed, around 230 articles were conducted in Egypt, 6 in Iraq, 2 in Algeria and 2 in Sudan. Some of the articles dealing with more than one crop and/or more than one type of radiation or radioisotope

  8. Irrigation and Maize Cultivation Erode Plant Diversity Within Crops in Mediterranean Dry Cereal Agro-Ecosystems

    Science.gov (United States)

    Fagúndez, Jaime; Olea, Pedro P.; Tejedo, Pablo; Mateo-Tomás, Patricia; Gómez, David

    2016-07-01

    The intensification of agriculture has increased production at the cost of environment and biodiversity worldwide. To increase crop yield in dry cereal systems, vast farmland areas of high conservation value are being converted into irrigation, especially in Mediterranean countries. We analyze the effect of irrigation-driven changes on the farm biota by comparing species diversity, community composition, and species traits of arable plants within crop fields from two contrasting farming systems (dry and irrigated) in Spain. We sampled plant species within 80 fields of dry wheat, irrigated wheat, and maize (only cultivated under irrigation). Wheat crops held higher landscape and per field species richness, and beta diversity than maize. Within the same type of crop, irrigated wheat hosted lower plant diversity than dry wheat at both field and landscape scales. Floristic composition differed between crop types, with higher frequencies of perennials, cosmopolitan, exotic, wind-pollinated and C4 species in maize. Our results suggest that irrigation projects, that transform large areas of dry cereal agro-ecosystems into irrigated crop systems dominated by maize, erode plant diversity. An adequate planning on the type and proportion of crops used in the irrigated agro-ecosystems is needed in order to balance agriculture production and biodiversity conservation.

  9. The theoretical relationship between foliage temperature and canopy resistance in sparse crops

    Science.gov (United States)

    Shuttleworth, W. James; Gurney, Robert J.

    1990-01-01

    One-dimensional, sparse-crop interaction theory is reformulated to allow calculation of the canopy resistance from measurements of foliage temperature. A submodel is introduced to describe eddy diffusion within the canopy which provides a simple, empirical simulation of the reported behavior obtained from a second-order closure model. The sensitivity of the calculated canopy resistance to the parameters and formulas assumed in the model is investigated. The calculation is shown to exhibit a significant but acceptable sensitivity to extreme changes in canopy aerodynamics, and to changes in the surface resistance of the substrate beneath the canopy at high and intermediate values of leaf area index. In very sparse crops changes in the surface resistance of the substrate are shown to contaminate the calculated canopy resistance, tending to amplify the apparent response to changes in water availability. The theory is developed to allow the use of a measurement of substrate temperature as an option to mitigate this contamination.

  10. Mechanisms of resistance to paraquat in plants.

    Science.gov (United States)

    Hawkes, Timothy R

    2014-09-01

    The aim of this brief review is to draw information from studies of the mechanism of evolved resistance in weeds, together with information from laboratory studies of paraquat tolerance in model plants. Plants having mutations that limit paraquat uptake into cytoplasm, that confer various stress tolerances or that have transgenes that co-express two or more of the chloroplast Halliwell-Asada cycle enzymes can all exhibit enhanced tolerance to paraquat. However, none of these mechanisms correspond to the high-level resistances that have evolved naturally in weeds. Most, but not all, of the evidence from studies of paraquat-resistant biotypes of weeds can reasonably be reconciled with the proposal of a single major gene mechanism that sequesters paraquat away from chloroplasts and into the vacuole. However, the molecular details of this putative mechanism remain ill-defined. © 2013 Society of Chemical Industry.

  11. Frost resistance of alpine woody plants

    Directory of Open Access Journals (Sweden)

    Gilbert eNeuner

    2014-12-01

    Full Text Available This report provides a brief review of key findings related to frost resistance in alpine woody plant species, summarizes data on their frost resistance, highlights the importance of freeze avoidance mechanisms, and indicates areas of future research.Freezing temperatures are possible throughout the whole growing period in the alpine life zone. Frost severity, comprised of both intensity and duration, becomes greater with increasing elevation and, there is also a greater probability, that small statured woody plants, may be insulated by snow cover.Several frost survival mechanisms have evolved in woody alpine plants in response to these environmental conditions. Examples of tolerance to extracellular freezing and freeze dehydration, life cycles that allow species to escape frost, and freeze avoidance mechanisms can all be found. Despite their specific adaption to the alpine environment, frost damage can occur in spring, while all alpine woody plants have a low risk of frost damage in winter. Experimental evidence indicates that premature deacclimation in Pinus cembra in the spring, and a limited ability of many species of alpine woody shrubs to rapidly reacclimate when they lose snow cover, resulting in reduced levels of frost resistance in the spring, may be particularly critical under the projected changes in climate.In this review, frost resistance and specific frost survival mechanisms of different organs (leaves, stems, vegetative and reproductive over-wintering buds, flowers and fruits and tissues are compared. The seasonal dynamics of frost resistance of leaves of trees, as opposed to woody shrubs, is also discussed. The ability of some tissues and organs to avoid freezing by supercooling, as visualized by high resolution infrared thermography, are also provided. Collectively, the report provides a review of the complex and diverse ways that woody plants survive in the frost dominated environment of the alpine life zone.

  12. Frost resistance in alpine woody plants.

    Science.gov (United States)

    Neuner, Gilbert

    2014-01-01

    This report provides a brief review of key findings related to frost resistance in alpine woody plant species, summarizes data on their frost resistance, highlights the importance of freeze avoidance mechanisms, and indicates areas of future research. Freezing temperatures are possible throughout the whole growing period in the alpine life zone. Frost severity, comprised of both intensity and duration, becomes greater with increasing elevation and, there is also a greater probability, that small statured woody plants, may be insulated by snow cover. Several frost survival mechanisms have evolved in woody alpine plants in response to these environmental conditions. Examples of tolerance to extracellular freezing and freeze dehydration, life cycles that allow species to escape frost, and freeze avoidance mechanisms can all be found. Despite their specific adaption to the alpine environment, frost damage can occur in spring, while all alpine woody plants have a low risk of frost damage in winter. Experimental evidence indicates that premature deacclimation in Pinus cembra in the spring, and a limited ability of many species of alpine woody shrubs to rapidly reacclimate when they lose snow cover, resulting in reduced levels of frost resistance in the spring, may be particularly critical under the projected changes in climate. In this review, frost resistance and specific frost survival mechanisms of different organs (leaves, stems, vegetative and reproductive over-wintering buds, flowers, and fruits) and tissues are compared. The seasonal dynamics of frost resistance of leaves of trees, as opposed to woody shrubs, is also discussed. The ability of some tissues and organs to avoid freezing by supercooling, as visualized by high resolution infrared thermography, are also provided. Collectively, the report provides a review of the complex and diverse ways that woody plants survive in the frost dominated environment of the alpine life zone.

  13. Next biotech plants: new traits, crops, developers and technologies for addressing global challenges.

    Science.gov (United States)

    Ricroch, Agnès E; Hénard-Damave, Marie-Cécile

    2016-08-01

    Most of the genetically modified (GM) plants currently commercialized encompass a handful of crop species (soybean, corn, cotton and canola) with agronomic characters (traits) directed against some biotic stresses (pest resistance, herbicide tolerance or both) and created by multinational companies. The same crops with agronomic traits already on the market today will continue to be commercialized, but there will be also a wider range of species with combined traits. The timeframe anticipated for market release of the next biotech plants will not only depend on science progress in research and development (R&D) in laboratories and fields, but also primarily on how demanding regulatory requirements are in countries where marketing approvals are pending. Regulatory constraints, including environmental and health impact assessments, have increased significantly in the past decades, delaying approvals and increasing their costs. This has sometimes discouraged public research entities and small and medium size plant breeding companies from using biotechnology and given preference to other technologies, not as stringently regulated. Nevertheless, R&D programs are flourishing in developing countries, boosted by the necessity to meet the global challenges that are food security of a booming world population while mitigating climate change impacts. Biotechnology is an instrument at the service of these imperatives and a wide variety of plants are currently tested for their high yield despite biotic and abiotic stresses. Many plants with higher water or nitrogen use efficiency, tolerant to cold, salinity or water submergence are being developed. Food security is not only a question of quantity but also of quality of agricultural and food products, to be available and accessible for the ones who need it the most. Many biotech plants (especially staple food) are therefore being developed with nutritional traits, such as biofortification in vitamins and metals. The main

  14. Modified cellulose synthase gene from Arabidopsis thaliana confers herbicide resistance to plants

    Science.gov (United States)

    Somerville, Chris R [Portola Valley, CA; Scheible, Wolf [Golm, DE

    2007-07-10

    Cellulose synthase ("CS"), a key enzyme in the biosynthesis of cellulose in plants is inhibited by herbicides comprising thiazolidinones such as 5-tert-butyl-carbamoyloxy-3-(3-trifluromethyl)phenyl-4-thiazolidinone (TZ), isoxaben and 2,6-dichlorobenzonitrile (DCB). Two mutant genes encoding isoxaben and TZ-resistant cellulose synthase have been isolated from isoxaben and TZ-resistant Arabidopsis thaliana mutants. When compared with the gene coding for isoxaben or TZ-sensitive cellulose synthase, one of the resistant CS genes contains a point mutation, wherein glycine residue 998 is replaced by an aspartic acid. The other resistant mutation is due to a threonine to isoleucine change at amino acid residue 942. The mutant CS gene can be used to impart herbicide resistance to a plant; thereby permitting the utilization of the herbicide as a single application at a concentration which ensures the complete or substantially complete killing of weeds, while leaving the transgenic crop plant essentially undamaged.

  15. Effect of tillage and crop residue on soil temperature following planting for a Black soil in Northeast China.

    Science.gov (United States)

    Shen, Yan; McLaughlin, Neil; Zhang, Xiaoping; Xu, Minggang; Liang, Aizhen

    2018-03-14

    Crop residue return is imperative to maintain soil health and productivity but some farmers resist adopting conservation tillage systems with residue return fearing reduced soil temperature following planting and crop yield. Soil temperatures were measured at 10 cm depth for one month following planting from 2004 to 2007 in a field experiment in Northeast China. Tillage treatments included mouldboard plough (MP), no till (NT), and ridge till (RT) with maize (Zea mays L.) and soybean (Glycine max Merr.) crops. Tillage had significant effects on soil temperature in 10 of 15 weekly periods. Weekly average NT soil temperature was 0-1.5 °C lower than MP, but the difference was significant (P temperature. Higher residue coverage caused lower soil temperature; the effect was greater for maize than soybean residue. Residue type had significant effect on soil temperature in 9 of 15 weekly periods with 0-1.9 °C lower soil temperature under maize than soybean residue. Both tillage and residue had small but inconsistent effect on soil temperature following planting in Northeast China representative of a cool to temperate zone.

  16. Resistance of plants to gravitational force.

    Science.gov (United States)

    Soga, Kouichi

    2013-09-01

    Developing resistance to gravitational force is a critical response for terrestrial plants to survive under 1 × g conditions. We have termed this reaction "gravity resistance" and have analyzed its nature and mechanisms using hypergravity conditions produced by centrifugation and microgravity conditions in space. Our results indicate that plants develop a short and thick body and increase cell wall rigidity to resist gravitational force. The modification of body shape is brought about by the rapid reorientation of cortical microtubules that is caused by the action of microtubule-associated proteins in response to the magnitude of the gravitational force. The modification of cell wall rigidity is regulated by changes in cell wall metabolism that are caused by alterations in the levels of cell wall enzymes and in the pH of apoplastic fluid (cell wall fluid). Mechanoreceptors on the plasma membrane may be involved in the perception of the gravitational force. In this review, we discuss methods for altering gravitational conditions and describe the nature and mechanisms of gravity resistance in plants.

  17. Tissue culture as a plant production technique for horticultural crops ...

    African Journals Online (AJOL)

    Over 100 years ago, Haberlandt envisioned the concept of plant tissue culture and provided the groundwork for the cultivation of plant cells, tissues and organs in culture. Initially plant tissue cultures arose as a research tool and focused on attempts to culture and study the development of small, isolated cells and segments ...

  18. Models and tests of optimal density and maximal yield for crop plants.

    Science.gov (United States)

    Deng, Jianming; Ran, Jinzhi; Wang, Zhiqiang; Fan, Zhexuan; Wang, Genxuan; Ji, Mingfei; Liu, Jing; Wang, Yun; Liu, Jianquan; Brown, James H

    2012-09-25

    We introduce a theoretical framework that predicts the optimum planting density and maximal yield for an annual crop plant. Two critical parameters determine the trajectory of plant growth and the optimal density, N(opt), where canopies of growing plants just come into contact, and competition: (i) maximal size at maturity, M(max), which differs among varieties due to artificial selection for different usable products; and (ii) intrinsic growth rate, g, which may vary with variety and environmental conditions. The model predicts (i) when planting density is less than N(opt), all plants of a crop mature at the same maximal size, M(max), and biomass yield per area increases linearly with density; and (ii) when planting density is greater than N(opt), size at maturity and yield decrease with -4/3 and -1/3 powers of density, respectively. Field data from China show that most annual crops, regardless of variety and life form, exhibit similar scaling relations, with maximal size at maturity, M(max), accounting for most of the variation in optimal density, maximal yield, and energy use per area. Crops provide elegantly simple empirical model systems to study basic processes that determine the performance of plants in agricultural and less managed ecosystems.

  19. Leaf epidermal changes in three common crop plants found in a gas ...

    African Journals Online (AJOL)

    The study investigated the impact of gas flaring on soil and air quality, as well as quantitative and qualitative anatomical characters of three selected plants Musa paradisiaca, Carica papaya and Talinum triangulare in and around Oben Flow Station. Most of these test crop plants located around the gas flare site showed ...

  20. Plant domestication and the development of sea starwort (Aster tripolium L.) as a new vegetable crop.

    NARCIS (Netherlands)

    Wagenvoort, W.A.; Vooren, J.G.; Brandenburg, W.A.

    1989-01-01

    The germination, growth and quality of Aster tripolium L. was analysed to study cultivation of the wild leafy plant into a commercial vegetable crop. Soil type and soil condition (non-saline, brackish and saline)were basically proved in relation to germination capacity, yield and plant behaviour

  1. Evolution of crop production under a pseudo-space environment using model plants, Lotus japonicus

    Science.gov (United States)

    Tomita-Yokotani, Kaori; Motohashi, Kyohei; Omi, Naomi; Sato, Seigo; Aoki, Toshio; Hashimoto, Hirofumi; Yamashita, Masamichi

    Habitation in outer space is one of our challenges. We have been studying space agriculture and/or spacecraft agriculture to provide food and oxygen for the habitation area in the space environment. However, careful investigation should be made concerning the results of exotic environmental effects on the endogenous production of biologically active substances in indi-vidual cultivated plants in a space environment. We have already reported that the production of functional substances in cultivated plants as crops are affected by gravity. The amounts of the main physiological substances in these plants grown under terrestrial control were different from that grown in a pseudo-microgravity. These results suggested that the nutrition would be changed in the plants/crops grown in the space environment when human beings eat in space. This estimation required us to investigate each of the useful components produced by each plant grown in the space environment. These estimations involved several study fields, includ-ing nutrition, plant physiology, etc. On the other hand, the analysis of model plant genomes has recently been remarkably advanced. Lotus japonicus, a leguminous plant, is also one of the model plant. The leguminosae is a large family in the plant vegetable kingdom and almost the entire genome sequence of Lotus japonicus has been determined. Nitrogen fixation would be possible even in a space environment. We are trying to determine the best conditions and evolution for crop production using the model plants.

  2. Artificial mutagenesis as an aid in overcoming genetic vulnerability of crop plants.

    Science.gov (United States)

    Konzak, C F; Nilan, R A; Kleinhofs, A

    Artificially induced genetic variation is being used effectively to supplement or complement sources of natural origin for practical plant breeding. Thus, creating genetic variation uill become increasingly important as crop genetic resources become more difficult to obtain via plant exploration. The aritificial induction of useful genetic variation offers important elements that can be used for overcoming genetic vulnerability: (1) new, previously unknown alleles can be induced in crop plant species to broaden the base of variation; (2) useful genetic variation can be induced in modern cultivars helping to shorten breeding time or to extend production "life"; (3) characteristics of existing genetic resource stocks can be improved to make them more useful in breeding; and (4) recombination in crosses may be enhanced. The performance of induced mutant crop cultivars and the successful uses of induced genetic variation in cross breeding indicate that artificial mutagenesis will play an increasingly greater role in plant breeding.

  3. Plant domestication versus crop evolution: a conceptual framework for cereals and grain legumes.

    Science.gov (United States)

    Abbo, Shahal; Pinhasi van-Oss, Ruth; Gopher, Avi; Saranga, Yehoshua; Ofner, Itai; Peleg, Zvi

    2014-06-01

    'Domestication syndrome' (DS) denotes differences between domesticated plants and their wild progenitors. Crop plants are dynamic entities; hence, not all parameters distinguishing wild progenitors from cultigens resulted from domestication. In this opinion article, we refine the DS concept using agronomic, genetic, and archaeobotanical considerations by distinguishing crucial domestication traits from traits that probably evolved post-domestication in Near Eastern grain crops. We propose that only traits showing a clear domesticated-wild dimorphism represent the pristine domestication episode, whereas traits showing a phenotypic continuum between wild and domesticated gene pools mostly reflect post-domestication diversification. We propose that our approach may apply to other crop types and examine its implications for discussing the timeframe of plant domestication and for modern plant science and breeding. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. The role of effectors in nonhost resistance to filamentous plant pathogens

    Directory of Open Access Journals (Sweden)

    Remco eStam

    2014-11-01

    Full Text Available In nature, most plants are resistant to a wide range of phytopathogens. However, mechanisms contributing to this so-called nonhost resistance (NHR are poorly understood. Besides constitutive defences, plants have developed two layers of inducible defence systems. Plant innate immunity relies on recognition of conserved pathogen-associated molecular patterns (PAMPs. In compatible interactions, pathogenicity effector molecules secreted by the invader can suppress host defence responses and facilitate the infection process. Additionally, plants have evolved pathogen-specific resistance mechanisms based on recognition of these effectors, which causes secondary defence responses. The current effector-driven hypothesis is that nonhost resistance in plants that are distantly related to the host plant is triggered by PAMP recognition that cannot be efficiently suppressed by the pathogen, whereas in more closely related species, nonhost recognition of effectors would play a crucial role. In this review we give an overview of current knowledge of the role of effector molecules in host and nonhost resistance and place these findings in the context of the model. We focus on examples from filamentous pathogens (fungi and oomycetes, discuss their implications for the field of plant-pathogen interactions and relevance in plant breeding strategies for development of durable resistance in crops.

  5. Glyphosate-resistant weeds of South American cropping systems: an overview.

    Science.gov (United States)

    Vila-Aiub, Martin M; Vidal, Ribas A; Balbi, Maria C; Gundel, Pedro E; Trucco, Frederico; Ghersa, Claudio M

    2008-04-01

    Herbicide resistance is an evolutionary event resulting from intense herbicide selection over genetically diverse weed populations. In South America, orchard, cereal and legume cropping systems show a strong dependence on glyphosate to control weeds. The goal of this report is to review the current knowledge on cases of evolved glyphosate-resistant weeds in South American agriculture. The first reports of glyphosate resistance include populations of highly diverse taxa (Lolium multiflorum Lam., Conyza bonariensis L., C. canadensis L.). In all instances, resistance evolution followed intense glyphosate use in fruit fields of Chile and Brazil. In fruit orchards from Colombia, Parthenium hysterophorus L. has shown the ability to withstand high glyphosate rates. The recent appearance of glyphosate-resistant Sorghum halepense L. and Euphorbia heterophylla L. in glyphosate-resistant soybean fields of Argentina and Brazil, respectively, is of major concern. The evolution of glyphosate resistance has clearly taken place in those agroecosystems where glyphosate exerts a strong and continuous selection pressure on weeds. The massive adoption of no-till practices together with the utilization of glyphosate-resistant soybean crops are factors encouraging increase in glyphosate use. This phenomenon has been more evident in Argentina and Brazil. The exclusive reliance on glyphosate as the main tool for weed management results in agroecosystems biologically more prone to glyphosate resistance evolution. Copyright (c) 2007 Society of Chemical Industry.

  6. Comparative genetics of crop plant domestication and evolution

    OpenAIRE

    Frary, Anne; Doğanlar, Sami

    2003-01-01

    Domesticated species differ from their wild ancestors and relatives for a set of traits that is known as the domestication syndrome. The most important syndrome traits include growth habit, flowering time, seed dispersal, gigantism and morphological diversity. This paper reviews what is known about the genetic control of domestication traits with an emphasis on comparative analyses that examine this control in two or more crop species. Such analyses indicate that although most domestication t...

  7. Comparative Genetics of Crop Plant Domestication and Evolution

    OpenAIRE

    FRARY, Anne; DOĞANLAR, Sami

    2003-01-01

    Domesticated species differ from their wild ancestors and relatives for a set of traits that is known as the domestication syndrome. The most important syndrome traits include growth habit, flowering time, seed dispersal, gigantism and morphological diversity. This paper reviews what is known about the genetic control of domestication traits with an emphasis on comparative analyses that examine this control in two or more crop species. Such analyses indicate that although most domestication t...

  8. Plant genome editing made easy: targeted mutagenesis in model and crop plants using the CRISPR/Cas system

    OpenAIRE

    Belhaj, Khaoula; Chaparro-Garcia, Angela; Kamoun, Sophien; Nekrasov, Vladimir

    2013-01-01

    Targeted genome engineering (also known as genome editing) has emerged as an alternative to classical plant breeding and transgenic (GMO) methods to improve crop plants. Until recently, available tools for introducing site-specific double strand DNA breaks were restricted to zinc finger nucleases (ZFNs) and TAL effector nucleases (TALENs). However, these technologies have not been widely adopted by the plant research community due to complicated design and laborious assembly of specific DNA b...

  9. Uncertain and multi-objective programming models for crop planting structure optimization

    Directory of Open Access Journals (Sweden)

    Mo LI,Ping GUO,Liudong ZHANG,Chenglong ZHANG

    2016-03-01

    Full Text Available Crop planting structure optimization is a significant way to increase agricultural economic benefits and improve agricultural water management. The complexities of fluctuating stream conditions, varying economic profits, and uncertainties and errors in estimated modeling parameters, as well as the complexities among economic, social, natural resources and environmental aspects, have led to the necessity of developing optimization models for crop planting structure which consider uncertainty and multi-objectives elements. In this study, three single-objective programming models under uncertainty for crop planting structure optimization were developed, including an interval linear programming model, an inexact fuzzy chance-constrained programming (IFCCP model and an inexact fuzzy linear programming (IFLP model. Each of the three models takes grayness into account. Moreover, the IFCCP model considers fuzzy uncertainty of parameters/variables and stochastic characteristics of constraints, while the IFLP model takes into account the fuzzy uncertainty of both constraints and objective functions. To satisfy the sustainable development of crop planting structure planning, a fuzzy-optimization-theory-based fuzzy linear multi-objective programming model was developed, which is capable of reflecting both uncertainties and multi-objective. In addition, a multi-objective fractional programming model for crop structure optimization was also developed to quantitatively express the multi-objective in one optimization model with the numerator representing maximum economic benefits and the denominator representing minimum crop planting area allocation. These models better reflect actual situations, considering the uncertainties and multi-objectives of crop planting structure optimization systems. The five models developed were then applied to a real case study in Minqin County, north-west China. The advantages, the applicable conditions and the solution methods

  10. The rise and future of glyphosate and glyphosate-resistant crops.

    Science.gov (United States)

    Green, Jerry M

    2018-05-01

    Glyphosate and glyphosate-resistant crops had a revolutionary impact on weed management practices, but the epidemic of glyphosate-resistant (GR) weeds is rapidly decreasing the value of these technologies. In areas that fully adopted glyphosate and GR crops, GR weeds evolved and glyphosate and glyphosate traits now must be combined with other technologies. The chemical company solution is to combine glyphosate with other chemicals, and the seed company solution is to combine glyphosate resistance with other traits. Unfortunately, companies have not discovered a new commercial herbicide mode-of-action for over 30 years and have already developed or are developing traits for all existing herbicide types with high utility. Glyphosate mixtures and glyphosate trait combinations will be the mainstays of weed management for many growers, but are not going to be enough to keep up with the capacity of weeds to evolve resistance. Glufosinate, auxin, HPPD-inhibiting and other herbicide traits, even when combined with glyphosate resistance, are incremental and temporary solutions. Herbicide and seed businesses are not going to be able to support what critics call the chemical and transgenic treadmills for much longer. The long time without the discovery of a new herbicide mode-of-action and the epidemic of resistant weeds is forcing many growers to spend much more to manage weeds and creating a worst of times, best of times predicament for the crop protection and seed industry. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  11. Identification of tree-crop rootstocks with resistance to Armillaria root disease.

    Science.gov (United States)

    Armillaria root disease attacks a broad range of tree crops in California. Instead of re-tooling ineffective conventional controls, namely soil fumigation, we focused on identification of Armillaria-resistant Juglans rootstocks, as part of a collaborative project to identify rootstocks with resistan...

  12. Application of Biophysics Methods in Crop Production and Plant Protection

    OpenAIRE

    Vasilevski, Goce; Bosev, D; Mitrev, Sasa; Mihajlov, Ljupco; Vasilevski, N

    2004-01-01

    The plants have perfect and various synthetic possibilities. These possibilities led to development of complex organic matters, full of energy, from the simple inorganic organisms. That is why the plants have distictive and specific place among the life forms on our planet. Generally they are highly organized and dynamic organizams, who are moving and transfom1ing the organic mater in their potential chemical energy. Today it is well known that photosynthesis at plants is a unique bioenerg...

  13. Nematode parasites of animals are more prone to develop xenobiotic resistance than nematode parasites of plants.

    Science.gov (United States)

    Silvestre, A; Cabaret, J

    2004-06-01

    In this paper, we concentrate on a comparison of plant and animal-parasitic nematodes, to gain insight into the factors that influence the acquisition of the drug resistance by nematodes. Comparing nematode parasite of domestic animals and cultivated plants, it appears that drug resistance threatens only domestic animal production. Does the paucity of report on nematicide field resistance reflect reality or, is nematicide resistance bypassed by other management practices, specific to cultivated plants (i.e. agricultural control)? First, it seems that selection pressure by treatments in plants is not as efficient as selection pressure in ruminants. Agronomic practices (i.e. sanitation, early planting, usage of nematodes resistant cultivar and crop rotation) are frequently used to control parasitic-plant nematodes. Although the efficiency of such measures is generally moderate to high, integrated approaches are developing successfully in parasitic-plant nematode models. Secondly, the majority of anthelmintic resistance cases recorded in animal-parasitic nematodes concern drug families that are not used in plant-parasitic nematodes control (i.e. benzimidazoles, avermectines and levamisole). Thirdly, particular life traits of parasitic-plant nematodes (low to moderate fecundity and reproductive strategy) are expected to reduce probability of appearance and transmission of drug resistance genes. It has been demonstrated that, for a large number of nematodes such as Meloidogyne spp., the mode of reproduction by mitotic parthenogenesis reduced genetic diversity of populations which may prevent a rapid drug resistance development. In conclusion, anthelmintic resistance develops in nematode parasite of animals as a consequence of an efficient selection pressure. Early detection of anthelmintic resistance is then crucial: it is not possible to avoid it, but only to delay its development in farm animal industry.

  14. Nematode parasites of animals are more prone to develop xenobiotic resistance than nematode parasites of plants

    Directory of Open Access Journals (Sweden)

    Silvestre A.

    2004-06-01

    Full Text Available In this paper, we concentrate on a comparison of plant and animal-parasitic nematodes, to gain insight into the factors that influence the acquisition of the drug resistance by nematodes. Comparing nematode parasite of domestic animals and cultivated plants, it appears that drug resistance threatens only domestic animal production. Does the paucity of report on nematicide field resistance reflect reality or, is nematicide resistance bypassed by other management practices, specific to cultivated plants (i.e. agricultural control ? First, it seems that selection pressure by treatments in plants is not as efficient as selection pressure in ruminants. Agronomic practices (i.e. sanitation, early planting, usage of nematodes resistant cultivar and crop rotation are frequently used to control parasitic-plant nematodes. Although the efficiency of such measures is generally moderate to high, integrated approaches are developing successfully in parasitic-plant nematode models. Secondly, the majority of anthelmintic resistance cases recorded in animal-parasitic nematodes concern drug families that are not used in plant-parasitic nematodes control (i.e. benzimidazoles, avermectines and levamisole. Thirdly, particular life traits of parasitic-plant nematodes (low to moderate fecundity and reproductive strategy are expected to reduce probability of appearance and transmission of drug resistance genes. It has been demonstrated that, for a large number of nematodes such as Meloidogyne spp., the mode of reproduction by mitotic parthenogenesis reduced genetic diversity of populations which may prevent a rapid drug resistance development. In conclusion, anthelmintic resistance develops in nematode parasite of animals as a consequence of an efficient selection pressure. Early detection of anthelmintic resistance is then crucial : it is not possible to avoid it, but only to delay its development in farm animal industry.

  15. The Impact of "Coat Protein-Mediated Virus Resistance" in Applied Plant Pathology and Basic Research.

    Science.gov (United States)

    Lindbo, John A; Falk, Bryce W

    2017-06-01

    Worldwide, plant viruses cause serious reductions in marketable crop yield and in some cases even plant death. In most cases, the most effective way to control virus diseases is through genetically controlled resistance. However, developing virus-resistant (VR) crops through traditional breeding can take many years, and in some cases is not even possible. Because of this, the demonstration of the first VR transgenic plants in 1985 generated much attention. This seminal report served as an inflection point for research in both basic and applied plant pathology, the results of which have dramatically changed both basic research and in a few cases, commercial crop production. The typical review article on this topic has focused on only basic or only applied research results stemming from this seminal discovery. This can make it difficult for the reader to appreciate the full impact of research on transgenic virus resistance, and the contributions from fundamental research that led to translational applications of this technology. In this review, we take a global view of this topic highlighting the significant changes to both basic and applied plant pathology research and commercial food production that have accumulated in the last 30 plus years. We present these milestones in the historical context of some of the scientific, economic, and environmental drivers for developing specific VR crops. The intent of this review is to provide a single document that adequately records the significant accomplishments of researchers in both basic and applied plant pathology research on this topic and how they relate to each other. We hope this review therefore serves as both an instructional tool for students new to the topic, as well as a source of conversation and discussion for how the technology of engineered virus resistance could be applied in the future.

  16. Plant prebiotics and human health: Biotechnology to breed prebiotic-rich nutritious food crops

    OpenAIRE

    Dwivedi,Sangam; Sahrawat,Kanwar; Puppala,Naveen; Ortiz,Rodomiro

    2014-01-01

    Microbiota in the gut play essential roles in human health. Prebiotics are non-digestible complex carbohydrates 19 that are fermented in the colon, yielding energy and short chain fatty acids, and selectively promote the growth of 20 Bifidobacteria and Lactobacillae in the gastro-intestinal tract. Fructans and inulin are the best-characterized plant prebiotics. Many vegetable, root and tuber crops as well as some fruit crops are the best-known sources of prebiotic carbohydrates, while the pre...

  17. Plant prebiotics and human health: Biotechnology to breed prebiotic-rich nutritious food crops

    Directory of Open Access Journals (Sweden)

    Sangam Dwivedi

    2014-09-01

    Full Text Available Microbiota in the gut play essential roles in human health. Prebiotics are non-digestible complex carbohydrates that are fermented in the colon, yielding energy and short chain fatty acids, and selectively promote the growth of Bifidobacteria and Lactobacillae in the gastro-intestinal tract. Fructans and inulin are the best-characterized plant prebiotics. Many vegetable, root and tuber crops as well as some fruit crops are the best-known sources of prebiotic carbohydrates, while the prebiotic-rich grain crops include barley, chickpea, lentil, lupin, and wheat. Some prebiotic-rich crop germplasm have been reported in barley, chickpea, lentil, wheat, yacon, and Jerusalem artichoke. A few major quantitative trait loci and gene-based markers associated with high fructan are known in wheat. More targeted search in genebanks using reduced subsets (representing diversity in germplasm is needed to identify accessions with prebiotic carbohydrates. Transgenic maize, potato and sugarcane with high fructan, with no adverse effects on plant development, have been bred, which suggests that it is feasible to introduce fructan biosynthesis pathways in crops to produce health-imparting prebiotics. Developing prebiotic-rich and super nutritious crops will alleviate the widespread malnutrition and promote human health. A paradigm shift in breeding program is needed to achieve this goal and to ensure that newly-bred crop cultivars are nutritious, safe and health promoting.

  18. Plant Residual Management in different Crop Rotations System on Potato Tuber Yield Loss Affected by Wireworms

    Directory of Open Access Journals (Sweden)

    A. Zarea Feizabadi

    2016-07-01

    Full Text Available Introduction: Selection a proper crop rotation based on environmental conservation rules is a key factor for increasing long term productivity. On the other hand, the major problem in reaching agricultural sustainability is lack of soil organic matter. Recently, a new viewpoint has emerged based on efficient use of inputs, environmental protection, ecological economy, food supply and security. Crop rotation cannot supply and restore plant needed nutrients, so gradually the productivity of rotation system tends to be decreased. Returning the plant residues to the soil helps to increase its organic matter and fertility in long-term period. Wireworms are multi host pests and we can see them in wheat and barley too. The logic way for their control is agronomic practices like as crop rotation. Wireworms’ population and damages are increased with using grasses and small seed gramineas in mild winters, variation in cropping pattern, reduced chemical control, and cover crops in winter. In return soil cultivation, crop rotation, planting date, fertilizing, irrigation and field health are the examples for the effective factors in reducing wireworms’ damage. Materials and Methods: In order to study the effect of crop rotations, residue management and yield damage because of wireworms’ population in soil, this experiment was conducted using four rotation systems for five years in Jolgeh- Rokh agricultural research station. Crop rotations were included, 1 Wheat monoculture for the whole period (WWWWW, 2 Wheat- wheat- wheat- canola- wheat (WWWCW, 3 Wheat- sugar beet- wheat- potato- wheat (WSWPW, 4 Wheat- maize- wheat- potato- wheat (WMWPW as main plots and three levels of returning crop residues to soil (returning 0, 50 and 100% produced crop residues to soil were allocated as sub plots. This experiment was designed as split plot based on RCBD design with three replications. After ending each rotation treatment, the field was sowed with potato cv. Agria

  19. Single-tube hydroponics as a novel idea for small-scale production of crop seed in a plant incubator.

    Science.gov (United States)

    Kuroda, Masaharu; Ikenaga, Sachiko

    2015-01-01

    We present a novel protocol for small-scale production of crop seed in a plant incubator termed "Single-tube hydroponics." Our protocol minimizes the materials and methods for cultivation whereby a large number of independent plants can be cultured in a limited space. This study may aid in the improvement of crop seed components, especially in the cultivation of transgenic plants.

  20. Probabilistic tools for assessment of pest resistance risk associated to insecticidal transgenic crops

    Directory of Open Access Journals (Sweden)

    Maia Aline de Holanda Nunes

    2004-01-01

    Full Text Available One of the main risks associated to transgenic crops expressing Bacillus thuringiensis (Bt toxins is the evolution of pest resistance. The adoption of Bt crops requires environmental risk assessment that includes resistance risk estimation, useful for definition of resistance management strategies aiming to delay resistance evolution. In this context, resistance risk is defined as the probability of the Bt toxin resistance allele frequency (RFreq exceeding a critical value (CriticalFreq. Mathematical simulation models have been used to estimate (RFreq over pest generations. In 1998, Caprio developed a deterministic simulation model with few parameters that can be used to obtain RFreq point estimates from point information about model parameters and decision variables involved in that process. In this work, the resistance risk was estimated using Caprio´s model, by incorporating uncertainty to the resistance allele initial frequency (InitialFreq. The main objective was to evaluate the influence of different probability distribution functions on the risk estimates. The simulation results showed that the influence of InitialFreq input distributions on the risk estimates changes along pest generations. The risk estimates considering input Normal distribution for InitialFreq are similar to those ones obtained considering Triangular distribution if their variances are equal. The use of Uniform distribution instead the Normal or Triangular due to the lack of information about InitialFreq leads to an overestimation of risk estimates for the initial generations and sub estimation for the generations after the one for which the critical frequency is achieved.

  1. Grass plants crop water consumption model in urban parks located ...

    African Journals Online (AJOL)

    The most important issue is the to use of urban space to increase the number and size of green areas. As well as another important issue is to work towards maintaining these spaces. One such important effort is to meet the water needs of plants. Naturally, the amount of water needed by plants depends on the species.

  2. Editorial: Plant organ abscission: from models to crops

    Science.gov (United States)

    The shedding of plant organs is a highly coordinated process essential for both vegetative and reproductive development (Addicott, 1982; Sexton and Roberts, 1982; Roberts et al., 2002; Leslie et al., 2007; Roberts and Gonzalez-Carranza, 2007; Estornell et al., 2013). Research with model plants, name...

  3. Crops in silico: A community wide multi-scale computational modeling framework of plant canopies

    Science.gov (United States)

    Srinivasan, V.; Christensen, A.; Borkiewic, K.; Yiwen, X.; Ellis, A.; Panneerselvam, B.; Kannan, K.; Shrivastava, S.; Cox, D.; Hart, J.; Marshall-Colon, A.; Long, S.

    2016-12-01

    Current crop models predict a looming gap between supply and demand for primary foodstuffs over the next 100 years. While significant yield increases were achieved in major food crops during the early years of the green revolution, the current rates of yield increases are insufficient to meet future projected food demand. Furthermore, with projected reduction in arable land, decrease in water availability, and increasing impacts of climate change on future food production, innovative technologies are required to sustainably improve crop yield. To meet these challenges, we are developing Crops in silico (Cis), a biologically informed, multi-scale, computational modeling framework that can facilitate whole plant simulations of crop systems. The Cis framework is capable of linking models of gene networks, protein synthesis, metabolic pathways, physiology, growth, and development in order to investigate crop response to different climate scenarios and resource constraints. This modeling framework will provide the mechanistic details to generate testable hypotheses toward accelerating directed breeding and engineering efforts to increase future food security. A primary objective for building such a framework is to create synergy among an inter-connected community of biologists and modelers to create a realistic virtual plant. This framework advantageously casts the detailed mechanistic understanding of individual plant processes across various scales in a common scalable framework that makes use of current advances in high performance and parallel computing. We are currently designing a user friendly interface that will make this tool equally accessible to biologists and computer scientists. Critically, this framework will provide the community with much needed tools for guiding future crop breeding and engineering, understanding the emergent implications of discoveries at the molecular level for whole plant behavior, and improved prediction of plant and ecosystem

  4. Transgenic plants: resistance to abiotic and biotic stresses

    Directory of Open Access Journals (Sweden)

    Akila Wijerathna-Yapa

    2017-06-01

    Full Text Available Today’s crop breeding combined with improved agricultural management has brought substantial increases in food production. But irrigation, fertilizers pest management requires a high energy input that creates a drain on the already scare fossil fuels. It is thus clear that different strategy has to be adopted to increase crop productivity further to meet the needs of rapidly increasing world population. Crop breeders are endeavoring to meet this challenge by developing crops with higher yield, better resistance to pest, disease and weedicides, tolerance to various stress conditions.

  5. Parameters on the radionuclide transfer in crop plants for Korean food chain dose assessment

    International Nuclear Information System (INIS)

    Choi, Yong Ho; Lim, K. M.; Cho, Y. H.

    2001-12-01

    For more realistic assessment of Korean food chain radiation doses due to the operation of nuclear facilities, it is required to use domestically produced data for radionuclide transfer parameters in crop plants. In this report, results of last about 15 years' studies on radionuclide transfer parameters in major crop plants by the Korea Atomic Energy Research Institute, were summarized and put together. Soil-to-plant transfer factors, parameters quantifying the root uptake of radionuclides, were measured through greenhouse experiments and field studies. In addition to traditional transfer factors, which are based on the activity in unit weight of soil, those based on the activity applied to unit area of soil surface were also investigated. Interception factors, translocation factors and weathering half lives, parameters in relation to direct plant contamination, were investigated through greenhouse experiments. The levels of initial plant contamination with HTO and I2 vapor were described with absorption factors. Especially for HTO vapor, 3H levels in crop plants at harvest were expressed with TFWT (tissue free water tritium) reduction factors and OBT (organically bound tritium) production factors. The above-mentioned parameters generally showed great variations with soils, crops and radionuclide species and application times. On the basis of summarized results, the points to be amended or improved in food chain dose assessment models were discussed both for normal operation and for accidental release

  6. Photoreceptor Mediated Plant Growth Responses: Implications for Photoreceptor Engineering toward Improved Performance in Crops

    Directory of Open Access Journals (Sweden)

    Ophilia I. L. Mawphlang

    2017-07-01

    Full Text Available Rising temperatures during growing seasons coupled with altered precipitation rates presents a challenging task of improving crop productivity for overcoming such altered weather patterns and cater to a growing population. Light is a critical environmental factor that exerts a powerful influence on plant growth and development ranging from seed germination to flowering and fruiting. Higher plants utilize a suite of complex photoreceptor proteins to perceive surrounding red/far-red (phytochromes, blue/UV-A (cryptochromes, phototropins, ZTL/FKF1/LKP2, and UV-B light (UVR8. While genomic studies have also shown that light induces extensive reprogramming of gene expression patterns in plants, molecular genetic studies have shown that manipulation of one or more photoreceptors can result in modification of agronomically beneficial traits. Such information can assist researchers to engineer photoreceptors via genome editing technologies to alter expression or even sensitivity thresholds of native photoreceptors for targeting aspects of plant growth that can confer superior agronomic value to the engineered crops. Here we summarize the agronomically important plant growth processes influenced by photoreceptors in crop species, alongwith the functional interactions between different photoreceptors and phytohormones in regulating these responses. We also discuss the potential utility of synthetic biology approaches in photobiology for improving agronomically beneficial traits of crop plants by engineering designer photoreceptors.

  7. Phytohormones and their metabolic engineering for abiotic stress tolerance in crop plants

    Directory of Open Access Journals (Sweden)

    Shabir H. Wani

    2016-06-01

    Full Text Available Abiotic stresses including drought, salinity, heat, cold, flooding, and ultraviolet radiation causes crop losses worldwide. In recent times, preventing these crop losses and producing more food and feed to meet the demands of ever-increasing human populations have gained unprecedented importance. However, the proportion of agricultural lands facing multiple abiotic stresses is expected only to rise under a changing global climate fueled by anthropogenic activities. Identifying the mechanisms developed and deployed by plants to counteract abiotic stresses and maintain their growth and survival under harsh conditions thus holds great significance. Recent investigations have shown that phytohormones, including the classical auxins, cytokinins, ethylene, and gibberellins, and newer members including brassinosteroids, jasmonates, and strigolactones may prove to be important metabolic engineering targets for producing abiotic stress-tolerant crop plants. In this review, we summarize and critically assess the roles that phytohormones play in plant growth and development and abiotic stress tolerance, besides their engineering for conferring abiotic stress tolerance in transgenic crops. We also describe recent successes in identifying the roles of phytohormones under stressful conditions. We conclude by describing the recent progress and future prospects including limitations and challenges of phytohormone engineering for inducing abiotic stress tolerance in crop plants.

  8. On streamlining the Ukrainian names of plants. Information 5. Species names for pome fruit crops

    Directory of Open Access Journals (Sweden)

    В. М. Меженський

    2015-12-01

    Full Text Available To analyse the modern classification and nomenclature of species of pome fruit crops which varieties are listed in the State Register of Plants Varieties Suitable for Dissemination in Ukraine, and improve terminological system of the Ukrainian names of both species and garden crops. Results. Fruit cultivars and most apple clonal rootstocks belong to Malus pumila, and ornamental cultivars belong to Malus gloriosa. The most common scientific name of the cultivated apple, especially among horticulturists, is Malus domestica, although according to the principle of priority the name Malus pumila should have the advantage. As far as Nomenclature Committee for Vascular Plants has rejected the proposal to conserve the name Malus domestica, Malus pumila is correct name for the cultivated apple. The use of synonymic name Malus domestica should be avoided in both scientific and scientific-popular papers for stability of nomenclature. Pear cultivars listed in the State Register of Plants Varieties Suitable for Dissemination in Ukraine are presented by Pyrus communis, and pear rootstocks – by Cydonia oblonga. Fruit cultivars of the latter belong to separate fruit crop named quince. An apple-quince hybrid was registered as universal clonal rootstock for pome fruit crops. The State Register of Plants Varieties Suitable for Dissemination in Ukraine also contains nonconventional fruit crops such as Chaenomeles and hawthorn that consist of some species and nothospecies. Conclusions. In scientific publications one should stop the use of synonymic name Malus domestica in favour of the correct name for cultivated apple Malus pumila. Apple, pears and Chaenomeles cultivars listed in the State Register of Plants Varieties Suitable for Dissemination in Ukraine have a complex multispecies origin whereas quince, hawthorn and pear roostock cultivars systematically are monospecies. A universal roootstock of pome fruit crops is Cydolus, or apple-quince, that resulted

  9. Plant-Herbivore and Plant-Pollinator Interactions of the Developing Perennial Oilseed Crop, Silphium integrifolium.

    Science.gov (United States)

    Prasifka, J R; Mallinger, R E; Hulke, B S; Larson, S R; Van Tassel, D

    2017-12-08

    Sampling in Kansas and North Dakota documented the plant-herbivore and plant-pollinator interactions of the developing perennial oilseed crop, Silphium integrifolium Michx. The larva of the tortricid moth, Eucosma giganteana (Riley), was the most damaging floret- and seed-feeding pest in Kansas, with infested heads producing ≈85% (2015) or ≈45% (2016) fewer seeds than apparently undamaged heads. Necrosis of apical meristems caused stunting and delayed bloom in Kansas; though the source of the necrosis is not known, observations of the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois; Hemiptera: Miridae), in S. integrifolium terminals suggest a possible cause. In North Dakota, E. giganteana larvae were not found, but pupae of Neotephritis finalis (Loew; Diptera: Tephritidae), a minor pest of cultivated sunflower, were common in the heads of S. integrifolium. Bees appeared highly attracted to S. integrifolium, and in all but one observation, bees were seen actively collecting pollen. The most common bees included large apids (Apis mellifera L., Svastra obliqua [Say], Melissodes spp.) and small-bodied halictids (Lasioglossum [Dialictus] spp.). Controlled pollination experiments demonstrated that S. integrifolium is pollinator dependent, due to both mechanical barriers (imperfect florets and protogyny) and genetic self-incompatibility. Subsequent greenhouse tests and AFLP confirmation of putative self-progeny show that a low (<1%) level of self-pollination is possible. If genetic self-incompatibility is eventually reduced through breeding, mechanical barriers would maintain a reliance on bees to move pollen between male and female florets. Collectively, observations on S. integrifolium show that both herbivore and pollinator management are important to maximize seed production. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  10. Cellular basis of gravity resistance in plants

    Science.gov (United States)

    Hoson, Takayuki; Matsumoto, Shouhei; Inui, Kenichi; Zhang, Yan; Soga, Kouichi; Wakabayashi, Kazuyuki; Hashimoto, Takashi

    Mechanical resistance to the gravitational force is a principal gravity response in plants distinct from gravitropism. In the final step of gravity resistance, plants increase the rigidity of their cell walls via modifications to the cell wall metabolism and apoplastic environment. We studied cellular events that are related to the cell wall changes under hypergravity conditions produced by centrifugation. Hypergravity induced reorientation of cortical microtubules from transverse to longitudinal directions in epidermal cells of stem organs. In Arabidopsis tubulin mutants, the percentage of cells with longitudinal microtubules was high even at 1 g, and it was further increased by hypergravity. Hypocotyls of tubulin mutants also showed either left-handed or right-handed helical growth at 1 g, and the degree of twisting phenotype was intensified under hypergravity conditions. The left-handed helical growth mutants had right-handed microtubule arrays, whereas the right-handed mutant had left-handed arrays. There was a close correlation between the alignment angle of epidermal cell files and the alignment of cortical microtubules. Gadolinium ions suppressed both the twisting phenotype and reorientation of microtubules in tubulin mutants. These results support the hypothesis that cortical microtubules play an es-sential role in maintenance of normal growth phenotype against the gravitational force, and suggest that mechanoreceptors are involved in modifications to morphology and orientation of microtubule arrays by hypergravity. Actin microfilaments, in addition to microtubules, may be involved in gravity resistance. The nucleus of epidermal cells of azuki bean epicotyls, which is present almost in the center of the cell at 1 g, was displaced to the cell bottom by increasing the magnitude of gravity. Cytochalasin D stimulated the sedimentation by hypergravity of the nu-cleus, suggesting that the positioning of the nucleus is regulated by actin microfilaments, which is

  11. EFFECT OF COVER CROPS ON SOIL ATTRIBUTES, PLANT NUTRITION, AND IRRIGATED TROPICAL RICE YIELD

    Directory of Open Access Journals (Sweden)

    ANDRE FROES DE BORJA REIS

    2017-01-01

    Full Text Available In flood plains, cover crops are able to alter soil properties and significantly affect rice nutrition and yield. The aims of this study were to determine soil properties, plant nutrition, and yield of tropical rice cultivated on flood plains after cover crop cultivation with conventional tillage (CT and no-tillage system (NTS at low and high nitrogen (N fertilization levels. The experimental design was a randomized block in a split-split-plot scheme with four replications. In the main plots were cover crops sunhemp (Crotalaria juncea and C. spectabilis, velvet bean (Mucuna aterrima, jackbean (Canavalia ensiformis, pigeon pea (Cajanus cajan, Japanese radish (Raphanus sativus, cowpea (Vigna unguiculata and a fallow field. In the subplots were the tillage systems (CT or NTS. The nitrogen fertilization levels in the sub-subplots were (10 kg N ha-1 and 45 kg N ha-1. All cover crops except Japanese radish significantly increased mineral soil nitrogen and nitrate concentrations. Sunhemp, velvet bean, and cowpea significantly increased soil ammonium content. The NTS provides higher mineral nitrogen and ammonium content than that by CT. Overall, cover crops provided higher levels of nutrients to rice plants in NTS than in CT. Cover crops provide greater yield than fallow treatments. Rice yield was higher in NTS than in CT, and greater at a higher rather than lower nitrogen fertilization level.

  12. Prospects of herbivore egg-killing plant defenses for sustainable crop protection

    NARCIS (Netherlands)

    Fatouros, Nina E.; Cusumano, Antonino; Danchin, Etienne G.J.; Colazza, Stefano

    2016-01-01

    Due to a growing demand of food production worldwide, new strategies are suggested to allow for sustainable production of food with minimal effects on natural resources. A promising alternative to the application of chemical pesticides is the implementation of crops resistant to insect pests.

  13. Determination of Soil and Plant Water Balance and Its Critical Stages for Rainfed Wheat Using Crop Water Stress Index (CWSI

    Directory of Open Access Journals (Sweden)

    V. Feiziasl

    2014-12-01

    Full Text Available In order to determination of water stress threshold and dryland wheat genotypes water status in different nitrogen managements, this experiment was carried out in split split plot RCBD design in three replications in 2010-2011 cropping year. Treatments included: N application time (whole fertilization of N at planting time , and its split fertilization as 2/3 at planting time and 1/3 in early spring, N rates (0, 30, 60 and 90 kg ha-1 and 7 wheat genotypes. Also these genotypes were grown in supplemental irrigation condition for calculation of crop water stress index (CWSI parameters. Canopy temperature (Tc was measured in flowering and early milking stages. Crop water stress index (CWSI was calculated. A non-water stressed baseline (lower baseline were fitted as Tc-Ta=4.523-3.761×VPD; R2=0.92 and non-transpiring baseline (upper baseline determined 6 ºC for rainfed wheat genotypes. Water stress threshold was 0.4 and crossing of that occurred 8 days before heading stage. In water stress threshold boundary, was depleted 60 mm available water from 0 to 50 cm soil depth. There was negative significant relationship (p >0.01 between CWSI and grain yield in all treatments and different nitrogen rates. Nitrogen application reduced water stress and increased grain yield of rainfed wheat genotypes. Ohadi and Rasad genotypes showed highest resistance to water stress and high grain yield production for N30 in split and planting time application, respectively. Cereal4 and Rasad genotypes were suitable for N60 application in split and planting time application, respectively.

  14. High-throughput phenotyping of plant resistance to aphids by automated video tracking.

    Science.gov (United States)

    Kloth, Karen J; Ten Broeke, Cindy Jm; Thoen, Manus Pm; Hanhart-van den Brink, Marianne; Wiegers, Gerrie L; Krips, Olga E; Noldus, Lucas Pjj; Dicke, Marcel; Jongsma, Maarten A

    2015-01-01

    Piercing-sucking insects are major vectors of plant viruses causing significant yield losses in crops. Functional genomics of plant resistance to these insects would greatly benefit from the availability of high-throughput, quantitative phenotyping methods. We have developed an automated video tracking platform that quantifies aphid feeding behaviour on leaf discs to assess the level of plant resistance. Through the analysis of aphid movement, the start and duration of plant penetrations by aphids were estimated. As a case study, video tracking confirmed the near-complete resistance of lettuce cultivar 'Corbana' against Nasonovia ribisnigri (Mosely), biotype Nr:0, and revealed quantitative resistance in Arabidopsis accession Co-2 against Myzus persicae (Sulzer). The video tracking platform was benchmarked against Electrical Penetration Graph (EPG) recordings and aphid population development assays. The use of leaf discs instead of intact plants reduced the intensity of the resistance effect in video tracking, but sufficiently replicated experiments resulted in similar conclusions as EPG recordings and aphid population assays. One video tracking platform could screen 100 samples in parallel. Automated video tracking can be used to screen large plant populations for resistance to aphids and other piercing-sucking insects.

  15. Integrated genomics and molecular breeding approaches for dissecting the complex quantitative traits in crop plants.

    Science.gov (United States)

    Kujur, Alice; Saxena, Maneesha S; Bajaj, Deepak; Laxmi; Parida, Swarup K

    2013-12-01

    The enormous population growth, climate change and global warming are now considered major threats to agriculture and world's food security. To improve the productivity and sustainability of agriculture, the development of highyielding and durable abiotic and biotic stress-tolerant cultivars and/climate resilient crops is essential. Henceforth, understanding the molecular mechanism and dissection of complex quantitative yield and stress tolerance traits is the prime objective in current agricultural biotechnology research. In recent years, tremendous progress has been made in plant genomics and molecular breeding research pertaining to conventional and next-generation whole genome, transcriptome and epigenome sequencing efforts, generation of huge genomic, transcriptomic and epigenomic resources and development of modern genomics-assisted breeding approaches in diverse crop genotypes with contrasting yield and abiotic stress tolerance traits. Unfortunately, the detailed molecular mechanism and gene regulatory networks controlling such complex quantitative traits is not yet well understood in crop plants. Therefore, we propose an integrated strategies involving available enormous and diverse traditional and modern -omics (structural, functional, comparative and epigenomics) approaches/resources and genomics-assisted breeding methods which agricultural biotechnologist can adopt/utilize to dissect and decode the molecular and gene regulatory networks involved in the complex quantitative yield and stress tolerance traits in crop plants. This would provide clues and much needed inputs for rapid selection of novel functionally relevant molecular tags regulating such complex traits to expedite traditional and modern marker-assisted genetic enhancement studies in target crop species for developing high-yielding stress-tolerant varieties.

  16. Plant Resistance Inducers against Pathogens in Solanaceae Species-From Molecular Mechanisms to Field Application.

    Science.gov (United States)

    Alexandersson, Erik; Mulugeta, Tewodros; Lankinen, Åsa; Liljeroth, Erland; Andreasson, Erik

    2016-10-02

    This review provides a current summary of plant resistance inducers (PRIs) that have been successfully used in the Solanaceae plant family to protect against pathogens by activating the plant's own defence. Solanaceous species include many important crops such as potato and tomato. We also present findings regarding the molecular processes after application of PRIs, even if the number of such studies still remains limited in this plant family. In general, there is a lack of patterns regarding the efficiency of induced resistance (IR) both between and within solanaceous species. In many cases, a hypersensitivity-like reaction needs to form in order for the PRI to be efficient. "-Omics" studies have already given insight in the complexity of responses, and can explain some of the differences seen in efficacy of PRIs between and within species as well as towards different pathogens. Finally, examples of field applications of PRIs for solanaceous crops are presented and discussed. We predict that PRIs will play a role in future plant protection strategies in Solanaceae crops if they are combined with other means of disease control in different spatial and temporal combinations.

  17. IMI resistance associated to crop-weed hybridization in a natural Brassica rapa population: characterization and fate.

    Science.gov (United States)

    Ureta, M S; Torres Carbonell, F; Pandolfo, C; Presotto, A D; Cantamutto, M A; Poverene, M

    2017-03-01

    Wild turnip (Brassica rapa) is a common weed and a close relative to oilseed rape (Brassica napus). The Clearfield® production system is a highly adopted tool which provides an alternative solution for weed management, but its efficiency is threatened by gene transfer from crop to weed relatives. Crop-weed hybrids with herbicide resistance were found in the progeny of a B. rapa population gathered from a weedy stand on the borders of an oilseed rape (B. napus) imidazolinone (IMI)-resistant crop. Interspecific hybrids were confirmed by morphological traits in the greenhouse and experimental field, survival after imazethapyr applications, DNA content through flow cytometry, and pollen viability. The transference of herbicide resistance was demonstrated even in a particular situation of pollen competition between both an herbicide-resistant crop and a non-resistant crop. However, IMI resistance was not found in further generations collected at the same location. These results verify gene transmission from oilseed rape to B. rapa in the main crop area in Argentina where resistant and susceptible varieties are found and seed loss and crop volunteers are common. Hybridization, introgression, and herbicide selection would be associated with the loss of effectiveness of IMI technology.

  18. Large SNP arrays for genotyping in crop plants

    Indian Academy of Sciences (India)

    Genotyping with large numbers of molecular markers is now an indispensable tool within plant genetics and breeding. Especially through the identification of large numbers of single nucleotide polymorphism (SNP) markers using the novel high-throughput sequencing technologies, it is now possible to reliably identify many ...

  19. Relationships between phenological and yield traits of the plant crop ...

    African Journals Online (AJOL)

    ABB) and dessert bananas (AAA). In all the genomic groups plant height of RC at harvest of the PC was significantly correlated with days to flowering and yield of the RC. In the hybrid genotypes, the black sigatoka disease score of the PC ...

  20. Large SNP arrays for genotyping in crop plants

    Indian Academy of Sciences (India)

    2012-10-15

    Oct 15, 2012 ... Genotyping with large numbers of molecular markers is now an indispensable tool within plant genetics and breeding. Especially through the identification of large numbers of single nucleotide polymorphism (SNP) markers using the novel high-throughput sequencing technologies, it is now possible to ...

  1. Fitness of Bt-resistant cabbage loopers on Bt cotton plants.

    Science.gov (United States)

    Tetreau, Guillaume; Wang, Ran; Wang, Ping

    2017-10-01

    Development of resistance to the insecticidal toxins from Bacillus thuringiensis (Bt) in insects is the major threat to the continued success of transgenic Bt crops in agriculture. The fitness of Bt-resistant insects on Bt and non-Bt plants is a key parameter that determines the development of Bt resistance in insect populations. In this study, a comprehensive analysis of the fitness of Bt-resistant Trichoplusia ni strains on Bt cotton leaves was conducted. The Bt-resistant T. ni strains carried two genetically independent mechanisms of resistance to Bt toxins Cry1Ac and Cry2Ab. The effects of the two resistance mechanisms, individually and in combination, on the fitness of the T. ni strains on conventional non-Bt cotton and on transgenic Bt cotton leaves expressing a single-toxin Cry1Ac (Bollgard I) or two Bt toxins Cry1Ac and Cry2Ab (Bollgard II) were examined. The presence of Bt toxins in plants reduced the fitness of resistant insects, indicated by decreased net reproductive rate (R 0 ) and intrinsic rate of increase (r). The reduction in fitness in resistant T. ni on Bollgard II leaves was greater than that on Bollgard I leaves. A 12.4-day asynchrony of adult emergence between the susceptible T. ni grown on non-Bt cotton leaves and the dual-toxin-resistant T. ni on Bollgard II leaves was observed. Therefore, multitoxin Bt plants not only reduce the probability for T. ni to develop resistance but also strongly reduce the fitness of resistant insects feeding on the plants. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  2. Using modern plant breeding to improve the nutritional and technological qualities of oil crops

    OpenAIRE

    Murphy Denis J.

    2014-01-01

    The last few decades have seen huge advances in our understanding of plant biology and in the development of new technologies for the manipulation of crop plants. The application of relatively straightforward breeding and selection methods made possible the “Green Revolution” of the 1960s and 1970s that effectively doubled or trebled cereal production in much of the world and averted mass famine in Asia. During the 2000s, much attention has ...

  3. Local crop planting systems enhance insecticide-mediated displacement of two invasive leafminer fly.

    Directory of Open Access Journals (Sweden)

    Yulin Gao

    Full Text Available Liriomyza sativae and L. trifolii are highly invasive leafminer pests of vegetable crops that have invaded southern China in recent years. Liriomyza sativae was the first of these species to invade China, but it is now being displaced by L. trifolii. The rate and extent of this displacement vary across southern China. In Hainan, monocultures of highly valuable cowpea are planted and treated extensively with insecticides in attempts to control leafminer damage. In Guangdong, cowpea fields are interspersed with other less valuable crops, such as towel gourd (Luffa cylindrica, which receive significantly fewer insecticide applications than cowpea. To determine how differences in cropping systems influence the Liriomyza species composition, we conducted field trials in 2011 and 2012 in Guangdong where both species were present. We replicated conditions in Hainan by planting cowpea monocultures that were isolated from other agricultural fields, and we replicated conditions in Guangdong by planting cowpea in a mixed crop environment with towel gourd planted in neighboring plots. We then compared leafminer populations in cowpea treated with the insecticide avermectin and untreated cowpea. We also monitored leafminer populations in the untreated towel gourd. Untreated cowpea and towel gourd had comparatively low proportions of L. trifolii, which remained relatively stable over the course of each season. Avermectin applications led to increases in the proportions of L. trifolii, and after three weekly applications populations were >95% L. trifolii in both crop systems. However, the rate of change and persistence of L. trifolii in the mixed crop system were less than in the monocrop. These results indicate that L. trifolii is much less susceptible to avermectin than is L. sativae. Further, L. sativae was able to persist in the untreated towel gourd, which probably enabled it to recolonize treated cowpea.

  4. Nematode Interactions in Nature: Models for Sustainable Control of Nematode Pests of Crop Plants?

    NARCIS (Netherlands)

    Putten, van der W.H.; Cook, R.; Costa, S.; Davies, K.G.; Fargette, M.; Freitas, H.; Hol, W.H.G.; Kerry, B.R.; Maher, N.; Mateille, T.; Moens, M.; Peña, de la E.; Piskiewicz, A.M.; Raeymaekers, A.D.W.; Rodriquez-Echeverria, S.; Wurff, van der A.W.G.

    2006-01-01

    Plant-parasitic nematodes are major crop pests in agro-ecosystems while in nature their impact may range from substantial to no significant growth reduction. The aim of this review is to determine if nematode population control in natural ecosystems may provide us with a model for enhancing

  5. Nematode interactions in nature: models for sustainable control of nematode pests of crop plants?

    NARCIS (Netherlands)

    Van der Putten, W.H.; Cook, R.; Costa, S.R.; Davies, K.G.; Fargette, M.; Freitas, H.; Hol, W.H.G.; Kerry, B.R.; Maher, N.; Mateille, T.; Moens, M.; De la Peña, E.; Piskiewicz, A.; Raeymaekers, A.; Rodríguez-Echeverría, S.; Van der Wurff, A.W.G.

    2006-01-01

    Plant-parasitic nematodes are major crop pests in agro-ecosystems while in nature their impact may range from substantial to no significant growth reduction. The aim of this review is to determine if nematode population control in natural ecosystems may provide us with a model for enhancing

  6. Accurate measurement of transgene copy number in crop plants using droplet digital PCR

    Science.gov (United States)

    Technical abstract: Genetic transformation is a powerful means for the improvement of crop plants, but requires labor and resource intensive methods. An efficient method for identifying single copy transgene insertion events from a population of independent transgenic lines is desirable. Currently ...

  7. Accurate measure of transgene copy number in crop plants using droplet digital PCR

    Science.gov (United States)

    Genetic transformation is a powerful means for the improvement of crop plants, but requires labor- and resource-intensive methods. An efficient method for identifying single-copy transgene insertion events from a population of independent transgenic lines is desirable. Currently, transgene copy numb...

  8. Apomixis: Engineering the Ability to Harness Hybrid Vigor in Crop Plants.

    Science.gov (United States)

    Conner, Joann A; Ozias-Akins, Peggy

    2017-01-01

    Apomixis, commonly defined as asexual reproduction through seed, is a reproductive trait that occurs in only a few minor crops, but would be highly valuable in major crops. Apomixis results in seed-derived progenies that are genetically identical to their maternal parent. The advantage of apomixis would lie in seed propagation of elite food, feed, and biofuel crops that are heterozygous such as hybrid corn and switchgrass or self-pollinating crops for which no commercial-scale hybrid production system is available. While hybrid plants often outperform parental lines in growth and higher yields, production of hybrid seed is accomplished through carefully controlled, labor intensive crosses. Both small farmers in developing countries who produce their own seed and commercial companies that market hybrid seed could benefit from the establishment of engineered apomixis in plants. In this chapter, we review what has been learned from studying natural apomicts and mutations in sexual plants leading to apomixis-like development, plus discuss how the components of apomixis could be successfully engineered in plants.

  9. EFFECTS OF ATMOSPHERIC H2S ON THIOL COMPOSITION OF CROP PLANTS

    NARCIS (Netherlands)

    BUWALDA, F; DE KOK, LJ; Stulen, I.

    Exposure of crop plants to H2S resulted in an increase in thiol level and a change in the composition of the thiol pool. Non-leguminous species accumulated cysteine and glutathione in the light, whereas in the dark, substantial amounts of gamma-glutamyl-cysteine were also detected. In leguminous

  10. In-Vitro Whole-Seedling Assay For Evaluating Non-Host Crop Plant ...

    African Journals Online (AJOL)

    In-Vitro Whole-Seedling Assay For Evaluating Non-Host Crop Plant Induction Of Germination Of Witch Weed Seeds. ... soybean (Glycine max), and three groundnut (Arachis hypogea ), in addition to maize (Zea mays L.) hybrids 8338-1 and 9022-13 (used as checks) were screened against three S. hermonthica populations.

  11. Plant resistance genes : their structure, function and evolution

    NARCIS (Netherlands)

    Takken, F.L.W.; Joosten, M.H.A.J.

    2000-01-01

    Plants have developed efficient mechanisms to avoid infection or to mount responses that render them resistant upon attack by a pathogen. One of the best-studied defence mechanisms is based on gene-for-gene resistance through which plants, harbouring specific resistance (R) genes, specifically

  12. Native cell-death genes as candidates for developing wilt resistance in transgenic banana plants.

    Science.gov (United States)

    Ghag, Siddhesh B; Shekhawat, Upendra K Singh; Ganapathi, Thumballi R

    2014-07-04

    In order to feed an ever-increasing world population, there is an urgent need to improve the production of staple food and fruit crops. The productivity of important food and fruit crops is constrained by numerous biotic and abiotic factors. The cultivation of banana, which is an important fruit crop, is severely threatened by Fusarium wilt disease caused by infestation by an ascomycetes fungus Fusarium oxysporum f. sp. cubense (Foc). Since there are no established edible cultivars of banana resistant to all the pathogenic races of Foc, genetic engineering is the only option for the generation of resistant cultivars. Since Foc is a hemibiotrophic fungus, investigations into the roles played by different cell-death-related genes in the progression of Foc infection on host banana plants are important. Towards this goal, three such genes namely MusaDAD1, MusaBAG1 and MusaBI1 were identified in banana. The study of their expression pattern in banana cells in response to Foc inoculation (using Foc cultures or fungal toxins like fusaric acid and beauvericin) indicated that they were indeed differentially regulated by fungal inoculation. Among the three genes studied, MusaBAG1 showed the highest up-regulation upon Foc inoculation. Further, in order to characterize these genes in the context of Foc infection in banana, we generated transgenic banana plants constitutively overexpressing the three genes that were later subjected to Foc bioassays in a contained greenhouse. Among the three groups of transgenics tested, transformed banana plants overexpressing MusaBAG1 demonstrated the best resistance towards Foc infection. Further, these plants also showed the highest relative overexpression of the transgene (MusaBAG1) among the three groups of transformed plants generated. Our study showed for the first time that native genes like MusaBAG1 can be used to develop transgenic banana plants with efficient resistance towards pathogens like Foc. Published by Oxford University Press

  13. Plant Productivity and Characterization of Zeoponic Substrates after Three Successive Crops of Radish (Raphanus sativus L.)

    Science.gov (United States)

    Gruener, J. E.; Ming, Douglas W.; Galindo, C., Jr.; Henderson, K. E.; Golden, D. C.

    2007-01-01

    The National Aeronautics and Space Administration (NASA) has developed a zeolite-based synthetic substrate, termed zeoponics. The zeoponic substrate (consisting of NH4(-) and K-exchanged clinoptilolite, synthetic apatite, and dolomite) provides all of the plant-essential nutrients through mineral dissolution and ion exchange, with only the addition of water. Previous studies have shown high productivity of wheat in zeoponic substrates; however, no experiments have been conducted on other crops. The objective of this study was to determine the productivity and nutrient uptake of radish (Raphanus sativus L.) grown in zeoponic substrates with three successive crops in the same substrate. Radish was chosen because of its sensitivities to NH4(+). Average fresh weights of edible roots were similar for radish grown in zeoponic substrates watered with deionized H2O (10.97 g/plant) and in potting mix control substrate irrigated with nutrient solution (10.92 g/plant). Average fresh weight production of edible roots for radish grown in same zeoponic substrate increased in yield over time with the lowest yield in the first crop (7.10 g/plant) and highest in the third crop (13.90 g/plant). The Ca plant tissue levels in radishes (1.8-2.9 wt. %) grown in zeoponic substrates are lower than the suggested sufficient range of 3.0-4.5 wt. % Ca; however, the Ca level is highest (2.9 wt. %) in radishes grown in the third crop in the same zeoponic substrates. The higher radish yield in the third crop was attributed to a reduction in an NH4(-) induced Ca deficiency that has been previously described for wheat grown in zeoponic substrates. The P levels in plant tissues of radish grown in the zeoponic substrates ranged from 0.94-1.15 wt. %; which is slightly higher than the sufficient levels of 0.3-0.7 wt. %. With the exception of Ca and P, other macronutrient and micronutrient levels in radish grown in zeoponic substrates were well within the recommended sufficient ranges. After three

  14. A comparative analysis of nonhost resistance across the two Triticeae crop species wheat and barley

    NARCIS (Netherlands)

    Delventhal, Rhoda; Rajaraman, Jeyaraman; Stefanato, Francesca L.; Rehman, Sajid; Aghnoum, Reza; McGrann, Graham R.D.; Bolger, Marie; Usadel, Björn; Hedley, Pete E.; Boyd, Lesley; Niks, Rients E.; Schweizer, Patrick; Schaffrath, Ulrich

    2017-01-01

    Background: Nonhost resistance (NHR) protects plants against a vast number of non-adapted pathogens which implicates a potential exploitation as source for novel disease resistance strategies. Aiming at a fundamental understanding of NHR a global analysis of transcriptome reprogramming in the

  15. Are Sewage Treatment Plants Promoting Antibiotic Resistance?

    Science.gov (United States)

    1. Introduction 1.1. How bacteria exhibit resistance 1.1.1. Resistance to -lactams 1.1.2. Resistance to sulphonamides and trimethoprim 1.1.3. Resistance to macrolides 1.1.4. Resistance to fluoroquinolones 1.1.5. Resistance to tetracyclines 1.1.6. Resistance to nitroimidaz...

  16. Oxylipins and plant abiotic stress resistance.

    Science.gov (United States)

    Savchenko, T V; Zastrijnaja, O M; Klimov, V V

    2014-04-01

    Oxylipins are signaling molecules formed enzymatically or spontaneously from unsaturated fatty acids in all aerobic organisms. Oxylipins regulate growth, development, and responses to environmental stimuli of organisms. The oxylipin biosynthesis pathway in plants includes a few parallel branches named after first enzyme of the corresponding branch as allene oxide synthase, hydroperoxide lyase, divinyl ether synthase, peroxygenase, epoxy alcohol synthase, and others in which various biologically active metabolites are produced. Oxylipins can be formed non-enzymatically as a result of oxygenation of fatty acids by free radicals and reactive oxygen species. Spontaneously formed oxylipins are called phytoprostanes. The role of oxylipins in biotic stress responses has been described in many published works. The role of oxylipins in plant adaptation to abiotic stress conditions is less studied; there is also obvious lack of available data compilation and analysis in this area of research. In this work we analyze data on oxylipins functions in plant adaptation to abiotic stress conditions, such as wounding, suboptimal light and temperature, dehydration and osmotic stress, and effects of ozone and heavy metals. Modern research articles elucidating the molecular mechanisms of oxylipins action by the methods of biochemistry, molecular biology, and genetics are reviewed here. Data on the role of oxylipins in stress signal transduction, stress-inducible gene expression regulation, and interaction of these metabolites with other signal transduction pathways in cells are described. In this review the general oxylipin-mediated mechanisms that help plants to adjust to a broad spectrum of stress factors are considered, followed by analysis of more specific responses regulated by oxylipins only under certain stress conditions. New approaches to improvement of plant resistance to abiotic stresses based on the induction of oxylipin-mediated processes are discussed.

  17. Molecular Breeding to Create Optimized Crops: From Genetic Manipulation to Potential Applications in Plant Factories.

    Science.gov (United States)

    Hiwasa-Tanase, Kyoko; Ezura, Hiroshi

    2016-01-01

    Crop cultivation in controlled environment plant factories offers great potential to stabilize the yield and quality of agricultural products. However, many crops are currently unsuited to these environments, particularly closed cultivation systems, due to space limitations, low light intensity, high implementation costs, and high energy requirements. A major barrier to closed system cultivation is the high running cost, which necessitates the use of high-margin crops for economic viability. High-value crops include those with enhanced nutritional value or containing additional functional components for pharmaceutical production or with the aim of providing health benefits. In addition, it is important to develop cultivars equipped with growth parameters that are suitable for closed cultivation. Small plant size is of particular importance due to the limited cultivation space. Other advantageous traits are short production cycle, the ability to grow under low light, and high nutriculture availability. Cost-effectiveness is improved from the use of cultivars that are specifically optimized for closed system cultivation. This review describes the features of closed cultivation systems and the potential application of molecular breeding to create crops that are optimized for cost-effectiveness and productivity in closed cultivation systems.

  18. Molecular breeding to create optimized crops: from genetic manipulation to potential applications in plant factories

    Directory of Open Access Journals (Sweden)

    Kyoko eHiwasa-Tanase

    2016-04-01

    Full Text Available Crop cultivation in controlled environment plant factories offers great potential to stabilize the yield and quality of agricultural products. However, many crops are currently unsuited to these environments, particularly closed cultivation systems, due to space limitations, low light intensity, high implementation costs, and high energy requirements. A major barrier to closed system cultivation is the high running cost, which necessitates the use of high-margin crops for economic viability. High-value crops include those with enhanced nutritional value or containing additional functional components for pharmaceutical production or with the aim of providing health benefits. In addition, it is important to develop cultivars equipped with growth parameters that are suitable for closed cultivation. Small plant size is of particular importance due to the limited cultivation space. Other advantageous traits are short production cycle, the ability to grow under low light, and high nutriculture availability. Cost-effectiveness is improved from the use of cultivars that are specifically optimized for closed system cultivation. This review describes the features of closed cultivation systems and the potential application of molecular breeding to create crops that are optimized for cost-effectiveness and productivity in closed cultivation systems.

  19. Early warning of cotton bollworm resistance associated with intensive planting of Bt cotton in China.

    Directory of Open Access Journals (Sweden)

    Haonan Zhang

    Full Text Available Transgenic crops producing Bacillus thuringiensis (Bt toxins kill some key insect pests, but evolution of resistance by pests can reduce their efficacy. The predominant strategy for delaying pest resistance to Bt crops requires refuges of non-Bt host plants to promote survival of susceptible pests. To delay pest resistance to transgenic cotton producing Bt toxin Cry1Ac, farmers in the United States and Australia planted refuges of non-Bt cotton, while farmers in China have relied on "natural" refuges of non-Bt host plants other than cotton. Here we report data from a 2010 survey showing field-evolved resistance to Cry1Ac of the major target pest, cotton bollworm (Helicoverpa armigera, in northern China. Laboratory bioassay results show that susceptibility to Cry1Ac was significantly lower in 13 field populations from northern China, where Bt cotton has been planted intensively, than in two populations from sites in northwestern China where exposure to Bt cotton has been limited. Susceptibility to Bt toxin Cry2Ab did not differ between northern and northwestern China, demonstrating that resistance to Cry1Ac did not cause cross-resistance to Cry2Ab, and implying that resistance to Cry1Ac in northern China is a specific adaptation caused by exposure to this toxin in Bt cotton. Despite the resistance detected in laboratory bioassays, control failures of Bt cotton have not been reported in China. This early warning may spur proactive countermeasures, including a switch to transgenic cotton producing two or more toxins distinct from Cry1A toxins.

  20. Plant Resistance Inducers against Pathogens in Solanaceae Species—From Molecular Mechanisms to Field Application

    Science.gov (United States)

    Alexandersson, Erik; Mulugeta, Tewodros; Lankinen, Åsa; Liljeroth, Erland; Andreasson, Erik

    2016-01-01

    This review provides a current summary of plant resistance inducers (PRIs) that have been successfully used in the Solanaceae plant family to protect against pathogens by activating the plant’s own defence. Solanaceous species include many important crops such as potato and tomato. We also present findings regarding the molecular processes after application of PRIs, even if the number of such studies still remains limited in this plant family. In general, there is a lack of patterns regarding the efficiency of induced resistance (IR) both between and within solanaceous species. In many cases, a hypersensitivity-like reaction needs to form in order for the PRI to be efficient. “-Omics” studies have already given insight in the complexity of responses, and can explain some of the differences seen in efficacy of PRIs between and within species as well as towards different pathogens. Finally, examples of field applications of PRIs for solanaceous crops are presented and discussed. We predict that PRIs will play a role in future plant protection strategies in Solanaceae crops if they are combined with other means of disease control in different spatial and temporal combinations. PMID:27706100

  1. The impact of altered herbicide residues in transgenic herbicide-resistant crops on standard setting for herbicide residues

    NARCIS (Netherlands)

    Kleter, G.A.; Unsworth, J.B.; Harris, C.A.

    2011-01-01

    The global area covered with transgenic (genetically modified) crops has rapidly increased since their introduction in the mid-1990s. Most of these crops have been rendered herbicide resistant, for which it can be envisaged that the modification has an impact on the profile and level of herbicide

  2. Weed-crop competition effects on growth and yield of sugarcane planted using two methods

    International Nuclear Information System (INIS)

    Zafar, M.; Tanveer, A.; Cheema, Z.A.; Ashraf, M.

    2010-01-01

    Effect of planting techniques and weed-crop competition periods on yield potential of spring planted sugarcane variety HSF-240 was studied at the Ayub Agricultural Research Institute, Faisalabad, Pakistan. The experiment was laid out in RCBD with a split-plot arrangement, with four replications and net plot size of 3.6m x 10m. In the experiment, two planting techniques viz., 60 cm apart rows in flat sowing technique and 120 cm apart rows in trench sowing technique were randomized in main plots. Seven weed-crop competition periods viz., Zero (weed free), weed-crop competition for 45, 60, 75, 90, 105 days after sowing (DAS) and weedy check (full season weed-crop competition) were randomized in sub-plots. Sugarcane sown by trench method exhibited more leaf area index (LAI), average crop growth rate (ACGR) and yield contributing attributes. Trench sowing by yielding 72.22 and 75.08 t ha/sup -1/ stripped cane yields, significantly showed superiority over the flat sowing, which gave 64.13 and 66.04 t ha/sup -1/ stripped cane yields in 2005-06 and 2006- 07, respectively. Generally, there was an increase in weed population and biomass but decrease in leaf area index, crop growth rate and yield components with an increase in weed-crop competition period. A decrease of 10.06, 17.90, 22.42, 28.65, 37.64 and 56.89% in stripped cane yield was observed for weed-crop competition periods of 45, 60, 75, 90, 105 DAS and weedy check as compared with zero competition in 2005-06, respectively. In 2006-07, the respective decrease in stripped cane yield was 9.84, 18.76, 22.92, 27.98, 38.75, and 54.98%. Trench sowing at 1.2 m row spacing proved better sowing technique and 45 DAS was the critical period of weed-crop competition. (author)

  3. Transposable elements and genetic instabilities in crop plants

    Energy Technology Data Exchange (ETDEWEB)

    Burr, B.; Burr, F.

    1981-04-10

    Transposable elements have long been associated with certain unstable loci in maize and have been intensively studied by McClintock and others. It is known that a transposable element can control the expression of the structural genes at the locus where it resides. These controlling elements in maize are now beginning to be studied at the molecular level. Using recombinant molecular probes we have been able to describe the changes induced by the controlling element Ds at the shrunken locus. Ds elements appear to be large and dissimilar insertions into the wild-type locus - two elements actually map within the transcribed region of the gene. Genetic instabilities have been described in other economically important plants but the bases for these phenomena have not been understood. We believe that it is likely that some of these instabilities are the result of transposable element activity much as in the case of maize.

  4. Advances in plant proteomics toward improvement of crop productivity and stress resistancex

    Science.gov (United States)

    Hu, Junjie; Rampitsch, Christof; Bykova, Natalia V.

    2015-01-01

    Abiotic and biotic stresses constrain plant growth and development negatively impacting crop production. Plants have developed stress-specific adaptations as well as simultaneous responses to a combination of various abiotic stresses with pathogen infection. The efficiency of stress-induced adaptive responses is dependent on activation of molecular signaling pathways and intracellular networks by modulating expression, or abundance, and/or post-translational modification (PTM) of proteins primarily associated with defense mechanisms. In this review, we summarize and evaluate the contribution of proteomic studies to our understanding of stress response mechanisms in different plant organs and tissues. Advanced quantitative proteomic techniques have improved the coverage of total proteomes and sub-proteomes from small amounts of starting material, and characterized PTMs as well as protein–protein interactions at the cellular level, providing detailed information on organ- and tissue-specific regulatory mechanisms responding to a variety of individual stresses or stress combinations during plant life cycle. In particular, we address the tissue-specific signaling networks localized to various organelles that participate in stress-related physiological plasticity and adaptive mechanisms, such as photosynthetic efficiency, symbiotic nitrogen fixation, plant growth, tolerance and common responses to environmental stresses. We also provide an update on the progress of proteomics with major crop species and discuss the current challenges and limitations inherent to proteomics techniques and data interpretation for non-model organisms. Future directions in proteomics research toward crop improvement are further discussed. PMID:25926838

  5. Soil and plant nitrogen dynamics of a tomato crop under different fertilization strategies

    DEFF Research Database (Denmark)

    Doltra, Jordi; Muñoz, P; Antón, A

    2010-01-01

    . The model was calibrated using data from a previous experiment. No differences between treatments were observed with respect to yield or N content in marketable fruits. The amount of N left in the field at the end of the cropping period was significantly lower in TO than in TC and TM. Simulated plant growth......A field experiment was conducted in 2007 to investigate the effects of the N fertilizer source on the soil and plant N dynamics of a tomato crop grown in a sandy loam soil. The fertilization treatments were: mineral N-fertilization applied by fertigation (TM); organic N-fertilization (TO...... (TM) kg N ha-1. The N contents of plants sampled on three occasions during the growing period and those of marketable fruits were also analyzed. Total marketable yield was determined at the end of the harvest period. The EU-Rotate_N model was used to predict the effects of the applied treatments...

  6. [The application of genome editing in identification of plant gene function and crop breeding].

    Science.gov (United States)

    Zhou, Xiang-chun; Xing, Yong-zhong

    2016-03-01

    Plant genome can be modified via current biotechnology with high specificity and excellent efficiency. Zinc finger nucleases (ZFN), transcription activator-like effector nucleases (TALEN) and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 (Cas9) system are the key engineered nucleases used in the genome editing. Genome editing techniques enable gene targeted mutagenesis, gene knock-out, gene insertion or replacement at the target sites during the endogenous DNA repair process, including non-homologous end joining (NHEJ) and homologous recombination (HR), triggered by the induction of DNA double-strand break (DSB). Genome editing has been successfully applied in the genome modification of diverse plant species, such as Arabidopsis thaliana, Oryza sativa, and Nicotiana tabacum. In this review, we summarize the application of genome editing in identification of plant gene function and crop breeding. Moreover, we also discuss the improving points of genome editing in crop precision genetic improvement for further study.

  7. Improved methods for irrigation and planting of major crops in waterlogged areas

    International Nuclear Information System (INIS)

    Kahlown, M.A.; Iqbal, M.; Raoof, A.

    2002-01-01

    The improved irrigation methods for wheat and cotton were evaluated in the fordwah Eastern Sadigia (South) Irrigation and Drainage Project area, during 1996-97 and 1997-98 cropping seasons, under three water table depths. Irrigation methods for wheat included 70, 95 and 120 cm Beds, with Flat Basin, as a check for comparative evaluation. Cotton had Ridge-planting on the top and side, Bed and Furrow, and Flat Basin as control. These irrigation methods were compared at water table depths of < 1 m, 1-2 and 2-3 m. The wheat variety inqalab-91, and cotton cultivar, CIM-109, were planted during the 3rd week of November and May every year. All the inputs and management practices, such as seed-rate, fertilizer, seeding method, weed control, plant-protection measures, etc. were kept common. The results on cotton indicated maximum water-use efficiency with the Bed and Furrow Method of irrigation Followed by ridge planting. The traditional Flat-planting had the lowest yield and the highest water-consumption, resulting in the minimum water-use efficiency. In harmony with cotton, the Flat Method of planting had maximum water-consumption. For wheat crop, the water-use efficiency was in descending order, with 120, 95 and 70 cm for Bed and Flat Methods. Bed planting of 95 cm had a fairly high water-use efficiency and yields were more were more comparable than Flat planting. This method had a high level of adaptabilities, especially when the groundwater was close to the root-zone and higher possibilities, especially when the groundwater was close to the root-zone and higher possibility of crop-submergence are existent during rainy spells. The results of the investigation strongly favoured the Bed and furrow methods to irrigate cotton and wheat. However, under well-drained soil conditions, Bed planting of wheat is not recommended. (author)

  8. Molecular effects of resistance elicitors from biological origin and their potential for crop protection

    Science.gov (United States)

    Wiesel, Lea; Newton, Adrian C.; Elliott, Ian; Booty, David; Gilroy, Eleanor M.; Birch, Paul R. J.; Hein, Ingo

    2014-01-01

    Plants contain a sophisticated innate immune network to prevent pathogenic microbes from gaining access to nutrients and from colonizing internal structures. The first layer of inducible response is governed by the plant following the perception of microbe- or modified plant-derived molecules. As the perception of these molecules results in a plant response that can provide efficient resistance toward non-adapted pathogens they can also be described as “defense elicitors.” In compatible plant/microbe interactions, adapted microorganisms have means to avoid or disable this resistance response and promote virulence. However, this requires a detailed spatial and temporal response from the invading pathogens. In agricultural practice, treating plants with isolated defense elicitors in the absence of pathogens can promote plant resistance by uncoupling defense activation from the effects of pathogen virulence determinants. The plant responses to plant, bacterial, oomycete, or fungal-derived elicitors are not, in all cases, universal and need elucidating prior to the application in agriculture. This review provides an overview of currently known elicitors of biological rather than synthetic origin and places their activity into a molecular context. PMID:25484886

  9. Crop water productivity for sunflower under different irrigation regimes and plant spacing in Gezira Scheme, Sudan

    Directory of Open Access Journals (Sweden)

    Eman Rahamtalla Ahmed Elsheikh

    2015-12-01

    Full Text Available Two field experiments with Sunflower on deep cracking soil with heavy clay (vertisol were conducted at Gezira Research Station Farm during two executive winter seasons, in WadMedani, Sudan. The crop was sown in the third week of November and in the first week of December for seasons 2012 and 2013 respectively. The experimental design was split plot design with three replicates. The Sunflower hybrid tested in the study was Hysun 33. The objective of this study was to determine the effect of three different irrigation intervals of 10, 15 and 20 days and two intra-row plant spacings of 30 cm and 40 cm on yield and yield components of Sunflower. The seed yields obtained from the different treatments were in the ranges of 1890-3300 kg/ha and 1590-3290 kg/ha for the first and second season respectively. The corresponding computed on average crop water productivity was in the range of 0.31-0.43 kg/m3. The study clearly indicated that the highest seed yield was obtained when the crop was sown at 40 cm plant spacing and irrigated every 10 days. The highest crop water productivity was achieved from irrigation every15 days in both planting spacings

  10. Herbicide and cover crop residue integration for amaranth control in conservation agriculture cotton and implications for resistance management

    Science.gov (United States)

    Conservation agriculture practices are threatened by glyphosate-resistant Palmer amaranth. Integrated practices including PRE herbicides and high-residue conservation agriculture systems may decrease Amaranth emergence. Field experiments were conducted from autumn 2006 through cash crop harvest in...

  11. Cover Image Identification of Plant Species for Crop Pollinator Habitat Enhancement in the Northern Prairies

    Directory of Open Access Journals (Sweden)

    Diana Bizecki Robson

    2014-09-01

    Full Text Available Wild pollinators have a positive impact on the productivity of insect-pollinated crops. Consequently, landowners are being encouraged to maintain and grow wildflower patches to provide habitat for important pollinators. Research on plant-pollinator interaction matrices indicates that a small number of “core” plants provide a disproportionately high amount of pollen and nectar to insects. This matrix data can be used to help design wildflower plantings that provide optimal resources for desirable pollinators. Existing interaction matrices from three tall grass prairie preserves in the northern prairies were used to identify core plant species that are visited by wild pollinators of a common insect-pollinated crop, namely canola (Brassica napus L.. The wildflower preferences of each insect taxon were determined using quantitative insect visitation and floral abundance data. Phenology data were used to calculate the degree of floral synchrony between the wildflowers and canola. Using this information I ranked the 41 wildflowers that share insect visitors with canola according to how useful they are for providing pollinators with forage before and after canola flowers. The top five species were smooth blue aster (Symphyotrichum laeve (L. A. & D. Löve, stiff goldenrod (Solidago rigida L., wild bergamot (Monarda fistulosa L., purple prairie-clover (Dalea purpurea Vent. and Lindley’s aster (Symphyotrichum ciliolatum (Lindl. A. & D. Löve. By identifying the most important wild insects for crop pollination, and determining when there will be “pollen and nectar gaps”, appropriate plant species can be selected for companion plantings to increase pollinator populations and crop production.

  12. DNA damage and repair in plants – from models to crops

    Directory of Open Access Journals (Sweden)

    Vasilissa eManova

    2015-10-01

    Full Text Available The genomic integrity of every organism is constantly challenged by endogenous and exogenous DNA-damaging factors. Mutagenic agents cause reduced stability of plant genome and have a deleterious effect on development, and in the case of crop species lead to yield reduction. It is crucial for all organisms, including plants, to develop efficient mechanisms for maintenance of the genome integrity. DNA repair processes have been characterized in bacterial, fungal and mammalian model systems. The description of these processes in plants, in contrast, was initiated relatively recently and has been focused largely on the model plant Arabidopsis thaliana. Consequently, our knowledge about DNA repair in plant genomes- particularly in the genomes of crops plants- is by far more limited. However, the relatively small size of the Arabidopsis genome, its rapid life cycle and availability of various transformation methods make this species an attractive model for the study of eukaryotic DNA repair mechanisms and mutagenesis. Moreover, abnormalities in DNA repair which proved to be lethal for animal models are tolerated in plant genomes, although sensitivity to DNA damaging agents is retained. Due to the high conservation of DNA repair processes and factors mediating them among eukaryotes, genes and proteins that have been identified in model species may serve to identify homologous sequences in other species, including crop plants, in which these mechanisms are poorly understood. Crop breeding programs have provided remarkable advances in food quality and yield over the last century. Although the human population is predicted to peak by 2050, further advances in yield will be required to feed this population. Breeding requires genetic diversity. The biological impact of any mutagenic agent used for the creation of genetic diversity depends on the chemical nature of the induced lesions and on the efficiency and accuracy of their repair. More recent targeted

  13. Resistência de plantas aos herbicidas inibidores da acetolactato sintase Plant resistance to acetolactate synthase-inhibiting herbicides

    Directory of Open Access Journals (Sweden)

    M.A. Rizzardi

    2002-04-01

    Full Text Available A resistência de plantas aos herbicidas é conseqüência, na maioria das vezes, de mutação ou da preexistência de genes que conferem resistência à população. No caso dos herbicidas inibidores da acetolactato sintase (ALS ocorreram casos de resistência tanto em plantas daninhas quanto em culturas. Essa revisão foi realizada com o objetivo de discutir aspectos bioquímicos, genéticos e moleculares da resistência de plantas aos herbicidas inibidores da ALS, sendo destacados também os efeitos na ecofisiologia das plantas daninhas e em mutações que conferem resistência em plantas daninhas e a possibilidade de utilizá-las para o desenvolvimento de culturas resistentes aos inibidores da ALS. Em plantas daninhas, a resistência aos herbicidas inibidores da ALS resulta de uma ou mais mutações no gene que codifica a ALS; quando a herança desse gene é monogênica, ele possui característica dominante a semidominante. As substituições em uma única seqüência nucleotídica ocasionam alteração na ALS, conferindo resistência aos herbicidas inibidores dessa enzima. Embora o biótipo resistente apresente alteração genética e enzimática quando comparado com biótipo suscetível, o comportamento ecofisiológico dos biótipos resistentes e suscetíveis é similar. Essa característica tem implicações muito importantes no estabelecimento das populações resistentes. Já foram desenvolvidos cultivares resistentes para diversas culturas, incluindo arroz e milho, as quais variam no nível de resistência aos diferentes grupos químicos de herbicidas inibidores da ALS.Herbicide resistance in plants arises mostly through mutation or pre-existence of genes that confer resistance to the population. When using herbicides inhibitors of the acetolactate synthase (ALS, resistance has occurred in weeds as well as in crops. This literature review was conducted to discuss biochemical, genetic, and molecular aspects of plant resistance to ALS

  14. "Founder crops" v. wild plants: Assessing the plant-based diet of the last hunter-gatherers in southwest Asia

    Science.gov (United States)

    Arranz-Otaegui, Amaia; González Carretero, Lara; Roe, Joe; Richter, Tobias

    2018-04-01

    The Natufian culture (c. 14.6-11.5 ka cal. BP) represents the last hunter-gatherer society that inhabited southwest Asia before the development of plant food production. It has long been suggested that Natufians based their economy on the exploitation of the wild ancestors of the Neolithic "founder crops", and that these hunter-gatherers were therefore on the "threshold to agriculture". In this work we review the available data on Natufian plant exploitation and we report new archaeobotanical evidence from Shubayqa 1, a Natufian site located in northeastern Jordan (14.6-11.5 ka cal. BP). Shubayqa 1 has produced an exceptionally large plant assemblage, including direct evidence for the continuous exploitation of club-rush tubers (often regarded as "missing foods") and other wild plants, which were probably used as food, fuel and building materials. Taking together this data we evaluate the composition of archaeobotanical assemblages (plant macroremains) from the Natufian to the Early Pre-Pottery Neolithic B (EPPNB). Natufian assemblages comprise large proportions of non-founder plant species (>90% on average), amongst which sedges, small-seeded grasses and legumes, and fruits and nuts predominate. During the Pre-Pottery Neolithic, in particular the EPPNB, the presence of "founder crops" increases dramatically and constitute up to c. 42% of the archaeobotanical assemblages on average. Our results suggest that plant exploitation strategies during the Natufian were very different from those attested during subsequent Neolithic periods. We argue that historically driven interpretations of the archaeological record have over-emphasized the role of the wild ancestors of domesticated crops previous to the emergence of agriculture.

  15. Agrobiodiversity and genetic erosion of crop varieties and plant resources in the Central Great Caucasus

    Directory of Open Access Journals (Sweden)

    Maia Akhalkatsi

    2017-03-01

    Full Text Available Kazbegi Municipality is located in the Central Great Caucasus at an altitude between 1250 and 5047 m a.s.l. Agriculture of this area is extreme internal variability and complexity, with a multiplicity of highly localized providing the habitats and agricultural lands for much genetic erosion of crop varieties, animals, plants, fungi, and other life forms for wild plant resources. Historically, Kazbegi producers had begun cultivating the land to prepare for planting in of distribution local varieties of wheat, barley, rye, oats, etc. In the only cereals, legumes, herbs and some fruits are cultivated in alpine zone as the upper limit till the location of 2160 m a.s.l. Genetic erosion has been determined historically of aboriginal crops from sheep and cattle grazing problem and reached extreme levels from 1970s in Kazbegi Municipality and causes a problem to maintain agriculture. Plant resources remained in forests and subalpine grasslands and shrub lands. The problems of these materials are habitat degradation by disturbance in many forest types with destroyed and burned. Tree seedlings are grazing by animals and forest is not restoring naturally. Forest planting is good relation for restoration of plant wild species resources. Investigation on exchange on mountain agriculture and plant resources will now be rapidly accelerated in the vital interests of mountain communities.

  16. Control of plant virus diseases in cool-season grain legume crops.

    Science.gov (United States)

    Makkouk, Khaled M; Kumari, Safaa G; van Leur, Joop A G; Jones, Roger A C

    2014-01-01

    Cool-season grain legume crops become infected with a wide range of viruses, many of which cause serious diseases and major yield losses. This review starts by discussing which viruses are important in the principal cool-season grain legume crops in different parts of the world, the losses they cause and their economic impacts in relation to control. It then describes the main types of control measures available: host resistance, phytosanitary measures, cultural measures, chemical control, and biological control. Examples are provided of successful deployment of the different types of measures to control virus epidemics in cool-season grain legume crops. Next it emphasizes the need for integrated approaches to control because single control measures used alone rarely suffice to adequately reduce virus-induced yield losses in these crops. Development of effective integrated disease management (IDM) strategies depends on an interdisciplinary team approach to (i) understand the ecological and climatic factors which lead to damaging virus epidemics and (ii) evaluate the effectiveness of individual control measures. In addition to using virus-resistant cultivars, other IDM components include sowing virus-tested seed stocks, selecting cultivars with low seed transmission rates, using diverse phytosanitary or cultural practices that minimize the virus source or reduce its spread, and using selective pesticides in an environmentally responsible way. The review finishes by briefly discussing the implications of climate change in increasing problems associated with control and the opportunities to control virus diseases more effectively through new technologies.

  17. Inducing Fungus-Resistance into Plants through Biotechnology

    OpenAIRE

    Shabir Hussain WANI

    2010-01-01

    Plant diseases are caused by a variety of plant pathogens including fungi, and their management requires the use of techniques like transgenic technology, molecular biology, and genetics. There have been attempts to use gene technology as an alternative method to protect plants from microbial diseases, in addition to the development of novel agrochemicals and the conventional breeding of resistant cultivars. Various genes have been introduced into plants, and the enhanced resistance against f...

  18. Integrating high residue cover crops and weed control options for resistant weeds threatening conservation agriculture and water resources

    Science.gov (United States)

    Conservation tillage reduces the physical movement of soil to the minimum required for crop establishment and production. When consistently practiced as a soil and crop management system, it greatly reduces soil erosion and is recognized for the potential to improve soil quality and plant water avai...

  19. The role of ethylene perception in plant disease resistance

    NARCIS (Netherlands)

    Geraats, Bart Peter Johan

    2003-01-01

    Ethylene is a plant hormone that is involved in responses of the plant to various stress situations, such as pathogen attack. The role of ethylene in plant-pathogen interactions seems to be diverse. Exposure of plants to ethylene can induce disease resistance, but treatment with ethylene during

  20. Resistência das plantas a moléstias fúngicas Plant resistance to fungal diseases

    Directory of Open Access Journals (Sweden)

    Rodrigo Rodrigues Matiello

    1997-03-01

    Full Text Available As plantas apresentam resistência a moléstias causadas por fungos patogênicos em função da sua constituição genética e de falares do ambiente. Em programas de melhoramento genético, um dos principais objetivos é a obtenção de plantas com alto potencial de rendimento e com resistência às moléstias. Para aumentar a eficiência da seleção, é importante o conhecimento das bases genéticas da resistência. Como a variabilidade dos fungos é bastante ampla, há a necessidade da utilização de estratégias que reduzam a probabilidade de estabelecimento do patógeno nas culturas.Plant resistance to fungic diseases is due to their genetic constitution and environmental factors. In breeding programs, one of the main objectives is to obtain high grainyield potenlial plants with resistance to the prevalent diseases. Knowledge of genetic basis of resistance is importam to increase selection efficiency and due to the wide variability of fungi there is the necessity of using different strategies to reduce the probability of pathogen estabtishment in crops.

  1. A Vavilovian approach to discovering crop-associated microbes with potential to enhance plant immunity

    Directory of Open Access Journals (Sweden)

    Iago Lowe Hale

    2014-09-01

    Full Text Available Through active associations with a diverse community of largely non-pathogenic microbes, a plant may be thought of as possessing an extended genotype, an interactive cross-organismal genome with potential, exploitable implications for plant immunity. The successful enrichment of plant microbiomes with beneficial species has led to numerous commercial applications, and the hunt for new biocontrol organisms continues. Increasingly flexible and affordable sequencing technologies, supported by increasingly comprehensive taxonomic databases, make the characterization of non-model crop-associated microbiomes a widely accessible research method toward this end; and such studies are becoming more frequent. A summary of this emerging literature reveals, however, the need for a more systematic research lens in the face of what is already a metagenomics data deluge. Considering the processes and consequences of crop evolution and domestication, we assert that the judicious integration of in situ crop wild relatives into phytobiome research efforts presents a singularly powerful tool for separating signal from noise, thereby facilitating a more efficient means of identifying candidate plant-associated microbes with the potential for enhanci

  2. Efficient genome-wide genotyping strategies and data integration in crop plants.

    Science.gov (United States)

    Torkamaneh, Davoud; Boyle, Brian; Belzile, François

    2018-03-01

    Next-generation sequencing (NGS) has revolutionized plant and animal research by providing powerful genotyping methods. This review describes and discusses the advantages, challenges and, most importantly, solutions to facilitate data processing, the handling of missing data, and cross-platform data integration. Next-generation sequencing technologies provide powerful and flexible genotyping methods to plant breeders and researchers. These methods offer a wide range of applications from genome-wide analysis to routine screening with a high level of accuracy and reproducibility. Furthermore, they provide a straightforward workflow to identify, validate, and screen genetic variants in a short time with a low cost. NGS-based genotyping methods include whole-genome re-sequencing, SNP arrays, and reduced representation sequencing, which are widely applied in crops. The main challenges facing breeders and geneticists today is how to choose an appropriate genotyping method and how to integrate genotyping data sets obtained from various sources. Here, we review and discuss the advantages and challenges of several NGS methods for genome-wide genetic marker development and genotyping in crop plants. We also discuss how imputation methods can be used to both fill in missing data in genotypic data sets and to integrate data sets obtained using different genotyping tools. It is our hope that this synthetic view of genotyping methods will help geneticists and breeders to integrate these NGS-based methods in crop plant breeding and research.

  3. Impact of Cropping Systems, Soil Inoculum, and Plant Species Identity on Soil Bacterial Community Structure.

    Science.gov (United States)

    Ishaq, Suzanne L; Johnson, Stephen P; Miller, Zach J; Lehnhoff, Erik A; Olivo, Sarah; Yeoman, Carl J; Menalled, Fabian D

    2017-02-01

    Farming practices affect the soil microbial community, which in turn impacts crop growth and crop-weed interactions. This study assessed the modification of soil bacterial community structure by organic or conventional cropping systems, weed species identity [Amaranthus retroflexus L. (redroot pigweed) or Avena fatua L. (wild oat)], and living or sterilized inoculum. Soil from eight paired USDA-certified organic and conventional farms in north-central Montana was used as living or autoclave-sterilized inoculant into steam-pasteurized potting soil, planted with Am. retroflexus or Av. fatua and grown for two consecutive 8-week periods to condition soil nutrients and biota. Subsequently, the V3-V4 regions of the microbial 16S rRNA gene were sequenced by Illumina MiSeq. Treatments clustered significantly, with living or sterilized inoculum being the strongest delineating factor, followed by organic or conventional cropping system, then individual farm. Living inoculum-treated soil had greater species richness and was more diverse than sterile inoculum-treated soil (observed OTUs, Chao, inverse Simpson, Shannon, P soil contained more Chloroflexi and Acidobacteria, while the sterile inoculum soil had more Bacteroidetes, Firmicutes, Gemmatimonadetes, and Verrucomicrobia. Organically farmed inoculum-treated soil had greater species richness, more diversity (observed OTUs, Chao, Shannon, P soil. Cyanobacteria were higher in pots growing Am. retroflexus, regardless of inoculum type, for three of the four organic farms. Results highlight the potential of cropping systems and species identity to modify soil bacterial communities, subsequently modifying plant growth and crop-weed competition.

  4. Effects of planting date and plant density on crop growth of cut chrysanthemum

    NARCIS (Netherlands)

    Lee, J.H.; Heuvelink, E.; Challa, H.

    2002-01-01

    The effects of planting date (season) and plant density (32, 48 or 64 plants m-2) on growth of cut chrysanthemum (Chrysanthemum (Indicum group)) were investigated in six greenhouse experiments, applying the expolinear growth equation. Final plant fresh and dry mass and number of flowers per plant

  5. DRPPP: A machine learning based tool for prediction of disease resistance proteins in plants.

    Science.gov (United States)

    Pal, Tarun; Jaiswal, Varun; Chauhan, Rajinder S

    2016-11-01

    Plant disease outbreak is increasing rapidly around the globe and is a major cause for crop loss worldwide. Plants, in turn, have developed diverse defense mechanisms to identify and evade different pathogenic microorganisms. Early identification of plant disease resistance genes (R genes) can be exploited for crop improvement programs. The present prediction methods are either based on sequence similarity/domain-based methods or electronically annotated sequences, which might miss existing unrecognized proteins or low similarity proteins. Therefore, there is an urgent need to devise a novel machine learning technique to address this problem. In the current study, a SVM-based tool was developed for prediction of disease resistance proteins in plants. All known disease resistance (R) proteins (112) were taken as a positive set, whereas manually curated negative dataset consisted of 119 non-R proteins. Feature extraction generated 10,270 features using 16 different methods. The ten-fold cross validation was performed to optimize SVM parameters using radial basis function. The model was derived using libSVM and achieved an overall accuracy of 91.11% on the test dataset. The tool was found to be robust and can be used for high-throughput datasets. The current study provides instant identification of R proteins using machine learning approach, in addition to the similarity or domain prediction methods. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. RNA Interference: A Novel Source of Resistance to Combat Plant Parasitic Nematodes

    Directory of Open Access Journals (Sweden)

    Sagar Banerjee

    2017-05-01

    Full Text Available Plant parasitic nematodes cause severe damage and yield loss in major crops all over the world. Available control strategies include use of insecticides/nematicides but these have proved detrimental to the environment, while other strategies like crop rotation and resistant cultivars have serious limitations. This scenario provides an opportunity for the utilization of technological advances like RNA interference (RNAi to engineer resistance against these devastating parasites. First demonstrated in the model free living nematode, Caenorhabtidis elegans; the phenomenon of RNAi has been successfully used to suppress essential genes of plant parasitic nematodes involved in parasitism, nematode development and mRNA metabolism. Synthetic neurotransmitants mixed with dsRNA solutions are used for in vitro RNAi in plant parasitic nematodes with significant success. However, host delivered in planta RNAi has proved to be a pioneering phenomenon to deliver dsRNAs to feeding nematodes and silence the target genes to achieve resistance. Highly enriched genomic databases are exploited to limit off target effects and ensure sequence specific silencing. Technological advances like gene stacking and use of nematode inducible and tissue specific promoters can further enhance the utility of RNAi based transgenics against plant parasitic nematodes.

  7. Engineering host-derived resistance against plant parasites through RNA interference: challenges and opportunities.

    Science.gov (United States)

    Runo, Steven

    2011-01-01

    RNA interference (RNAi) has rapidly advanced to become a powerful genetic tool and holds promise to revolutionizing agriculture by providing a strategy for controlling a wide array of crop pests. Numerous studies document RNAi efficacy in achieving silencing in viruses, insects, nematodes and weeds parasitizing crops. In general, host derived pest resistance through RNAi is achieved by genetically transforming host plants with double stranded RNA constructs targeted at essential parasite genes leading to generation of small interfering RNAs (siRNAs). Small interfering RNAs formed in the host are then delivered to the parasite and transported to target cells. Delivery can be oral - worms and insects, viral infections, viruses - or through a vascular connections - parasitic plants, while delivery to target cells is by cell to cell systemic movement of the silencing signal. Despite the overall optimism in generating pest resistant crops through RNAi-mediated silencing, some hurdles have recently begun to emerge. Presently, the main challenge is delivery of sufficient siRNAs, in the right cells, and at the right time to mount; a strong, durable, and broad-spectrum posttranscriptional gene silencing (PTGS) signal. This review highlights the novel strategies available for improving host derived RNAi resistance in downstream applied agriculture.

  8. Landscape configurational heterogeneity by small-scale agriculture, not crop diversity, maintains pollinators and plant reproduction in western Europe.

    Science.gov (United States)

    Hass, Annika L; Kormann, Urs G; Tscharntke, Teja; Clough, Yann; Baillod, Aliette Bosem; Sirami, Clélia; Fahrig, Lenore; Martin, Jean-Louis; Baudry, Jacques; Bertrand, Colette; Bosch, Jordi; Brotons, Lluís; Burel, Françoise; Georges, Romain; Giralt, David; Marcos-García, María Á; Ricarte, Antonio; Siriwardena, Gavin; Batáry, Péter

    2018-02-14

    Agricultural intensification is one of the main causes for the current biodiversity crisis. While reversing habitat loss on agricultural land is challenging, increasing the farmland configurational heterogeneity (higher field border density) and farmland compositional heterogeneity (higher crop diversity) has been proposed to counteract some habitat loss. Here, we tested whether increased farmland configurational and compositional heterogeneity promote wild pollinators and plant reproduction in 229 landscapes located in four major western European agricultural regions. High-field border density consistently increased wild bee abundance and seed set of radish ( Raphanus sativus ), probably through enhanced connectivity. In particular, we demonstrate the importance of crop-crop borders for pollinator movement as an additional experiment showed higher transfer of a pollen analogue along crop-crop borders than across fields or along semi-natural crop borders. By contrast, high crop diversity reduced bee abundance, probably due to an increase of crop types with particularly intensive management. This highlights the importance of crop identity when higher crop diversity is promoted. Our results show that small-scale agricultural systems can boost pollinators and plant reproduction. Agri-environmental policies should therefore aim to halt and reverse the current trend of increasing field sizes and to reduce the amount of crop types with particularly intensive management. © 2018 The Author(s).

  9. Response of sunflower to different planting dates in cotton based cropping system

    International Nuclear Information System (INIS)

    Yousaf, M.; Shakoor, A.; Rana, M.A.

    2007-01-01

    A field study on sunflower (Helianthus annuus L) was conducted for three. years (1991-1993) on different planting dates. Two hybrids (Hysun-33 and PI-6480) were sown on five different dates with 15 days interval from January 15 to March 15 at Cotton Research Station, Multan. Significant higher seed yield of 1880 and 2097 kg ha-1 was obtained when the crop was planted on February 1 and 15 than other treatments. The yield significantly decreased when sunflower was planted on January 15 (1264 kg ha-l), March 1 (1382 kg ha-l) and March 15 (927 kg hall. Maturity period was longest (128 days) of early sown (January 15) and shortest of late sown (March 15) sunflower hybrids. Therefore, it can be concluded that sunflower planted on February 1 to 15 gave higher seed yield as well as allowed enough time for land preparation and thereby, planting of cotton crop in the same field during its regular planting time. (author)

  10. Accumulation of contaminants of emerging concern in food crops-part 2: Plant distribution.

    Science.gov (United States)

    Hyland, Katherine C; Blaine, Andrea C; Higgins, Christopher P

    2015-10-01

    Arid agricultural regions often turn to using treated wastewater (reclaimed water) to irrigate food crops. Concerns arise, however, when considering the potential for persistent contaminants of emerging concern to accumulate into plants intended for human consumption. The present study examined the accumulation of a suite of 9 contaminants of emerging concern into 2 representative food crops, lettuce and strawberry, following uptake via the roots and subsequent distribution to other plant tissues. Calculating accumulation metrics (concentration factors) allowed for comparison of the compartmental affinity of each chemical for each plant tissue compartment. The root concentration factor was found to exhibit a positive linear correlation with the pH-adjusted octanol-water partition coefficient (DOW ) for the target contaminants of emerging concern. Coupled with the concentration-dependent accumulation observed in the roots, this result implies that accumulation of these contaminants of emerging concern into plant roots is driven by passive partitioning. Of the contaminants of emerging concern examined, nonionizable contaminants, such as triclocarban, carbamazepine, and organophosphate flame retardants displayed the greatest potential for translocation from the roots to above-ground plant compartments. In particular, the organophosphate flame retardants displayed increasing affinity for shoots and fruits with decreasing size/octanol-water partition coefficient (KOW ). Cationic diphenhydramine and anionic sulfamethoxazole, once transported to the shoots of the strawberry plant, demonstrated the greatest potential of the contaminants examined to be then carried to the edible fruit portion. © 2015 SETAC.

  11. Breeding crop plants with deep roots: their role in sustainable carbon, nutrient and water sequestration

    Science.gov (United States)

    Kell, Douglas B.

    2011-01-01

    Background The soil represents a reservoir that contains at least twice as much carbon as does the atmosphere, yet (apart from ‘root crops’) mainly just the above-ground plant biomass is harvested in agriculture, and plant photosynthesis represents the effective origin of the overwhelming bulk of soil carbon. However, present estimates of the carbon sequestration potential of soils are based more on what is happening now than what might be changed by active agricultural intervention, and tend to concentrate only on the first metre of soil depth. Scope Breeding crop plants with deeper and bushy root ecosystems could simultaneously improve both the soil structure and its steady-state carbon, water and nutrient retention, as well as sustainable plant yields. The carbon that can be sequestered in the steady state by increasing the rooting depths of crop plants and grasses from, say, 1 m to 2 m depends significantly on its lifetime(s) in different molecular forms in the soil, but calculations (http://dbkgroup.org/carbonsequestration/rootsystem.html) suggest that this breeding strategy could have a hugely beneficial effect in stabilizing atmospheric CO2. This sets an important research agenda, and the breeding of plants with improved and deep rooting habits and architectures is a goal well worth pursuing. PMID:21813565

  12. Lodging resistance and yield potential of winter wheat: effect of planting density and genotype

    Directory of Open Access Journals (Sweden)

    Yonggui XIAO,Jianjun LIU,Haosheng LI,Xinyou CAO,Xianchun XIA,Zhonghu HE

    2015-06-01

    Full Text Available Improved lodging resistance is important for achieving high yield in irrigated environments. This study was conducted to determine genotypic variation in lodging resistance and related morphological traits among winter wheat cultivars planted at two densities, and to identify key traits associated with lodging resistance. Lodging performance of 28 genotypes, including 24 released cultivars and four advanced lines, was evaluated at 250 plants per square meter and 500 plants per square meter in Shandong province during the 2008ndash;2009 and 2009ndash;2010 crop seasons. At the higher density, the average grain yield was 2.6% higher, even though lodging score rose by as much as 136%. The higher planting density increased lodging through increased leaf area index (LAI, plant height, center of gravity and length of basal internodes, and reduced grain weight per spike and diameter of the lower two stem internodes. LAI, center of gravity and diameter of first internodes, as the important indicators for lodging resistance, were significantly correlated with lodging score, with R= 0.62, 0.59 and minus;0.52 (P<0.01, respectively. Plant pushing resistance was significantly associated with diameter and length of the first internodes (R = 0.71ndash;0.77, P<0.01, indicating it could be used to assess the strength of the lower stem. Higher planting density could be used to select genotypes with lodging resistance in irrigated environments. Cultivars carrying high plant density tolerance and high yield potential, such as Jimai 22 and Liangxing 66, were recommended as leading cultivars for production as well as elite crossing parents for further increasing yield potential in the Yellow and Huai Valleys Winter Wheat Zone in China.

  13. Insights into plant size-density relationships from models and agricultural crops.

    Science.gov (United States)

    Deng, Jianming; Zuo, Wenyun; Wang, Zhiqiang; Fan, Zhexuan; Ji, Mingfei; Wang, Genxuan; Ran, Jinzhi; Zhao, Changming; Liu, Jianquan; Niklas, Karl J; Hammond, Sean T; Brown, James H

    2012-05-29

    There is general agreement that competition for resources results in a tradeoff between plant mass, M, and density, but the mathematical form of the resulting thinning relationship and the mechanisms that generate it are debated. Here, we evaluate two complementary models, one based on the space-filling properties of canopy geometry and the other on the metabolic basis of resource use. For densely packed stands, both models predict that density scales as M(-3/4), energy use as M(0), and total biomass as M(1/4). Compilation and analysis of data from 183 populations of herbaceous crop species, 473 stands of managed tree plantations, and 13 populations of bamboo gave four major results: (i) At low initial planting densities, crops grew at similar rates, did not come into contact, and attained similar mature sizes; (ii) at higher initial densities, crops grew until neighboring plants came into contact, growth ceased as a result of competition for limited resources, and a tradeoff between density and size resulted in critical density scaling as M(-0.78), total resource use as M(-0.02), and total biomass as M(0.22); (iii) these scaling exponents are very close to the predicted values of M(-3/4), M(0), and M(1/4), respectively, and significantly different from the exponents suggested by some earlier studies; and (iv) our data extend previously documented scaling relationships for trees in natural forests to small herbaceous annual crops. These results provide a quantitative, predictive framework with important implications for the basic and applied plant sciences.

  14. Introduced sap-feeding insect pests of crop plants in the Maltese Islands

    OpenAIRE

    Mifsud, David; Watson, Gillian W.

    1999-01-01

    Sap-feeding insects within Hemiptera and Thysanoptera are some of the most important crop pests world-wide. Apart from the loss of yield they cause by sap depletion, saliva toxicity and soiling of the leaves, some species transmit serious plant virus diseases. Important sap-feeding species that have been introduced to the Maltese Islands include the whitefly Bemisia tabaci; the scale insects Pseudo coccus !ongispinus, Planococcus citri and lcerya purchasi; the aphids Aphis gossypii, Aphis spi...

  15. Insights into plant size-density relationships from models and agricultural crops

    Science.gov (United States)

    Deng, Jianming; Zuo, Wenyun; Wang, Zhiqiang; Fan, Zhexuan; Ji, Mingfei; Wang, Genxuan; Ran, Jinzhi; Zhao, Changming; Liu, Jianquan; Niklas, Karl J.; Hammond, Sean T.; Brown, James H.

    2012-01-01

    There is general agreement that competition for resources results in a tradeoff between plant mass, M, and density, but the mathematical form of the resulting thinning relationship and the mechanisms that generate it are debated. Here, we evaluate two complementary models, one based on the space-filling properties of canopy geometry and the other on the metabolic basis of resource use. For densely packed stands, both models predict that density scales as M−3/4, energy use as M0, and total biomass as M1/4. Compilation and analysis of data from 183 populations of herbaceous crop species, 473 stands of managed tree plantations, and 13 populations of bamboo gave four major results: (i) At low initial planting densities, crops grew at similar rates, did not come into contact, and attained similar mature sizes; (ii) at higher initial densities, crops grew until neighboring plants came into contact, growth ceased as a result of competition for limited resources, and a tradeoff between density and size resulted in critical density scaling as M−0.78, total resource use as M−0.02, and total biomass as M0.22; (iii) these scaling exponents are very close to the predicted values of M−3/4, M0, and M1/4, respectively, and significantly different from the exponents suggested by some earlier studies; and (iv) our data extend previously documented scaling relationships for trees in natural forests to small herbaceous annual crops. These results provide a quantitative, predictive framework with important implications for the basic and applied plant sciences. PMID:22586097

  16. Resistance (R) Genes: Applications and Prospects for Plant Biotechnology and Breeding.

    Science.gov (United States)

    Pandolfi, Valesca; Neto, Jose Ribamar Costa Ferreira; da Silva, Manasses Daniel; Amorim, Lidiane Lindinalva Barbosa; Wanderley-Nogueira, Ana Carolina; de Oliveira Silva, Roberta Lane; Kido, Ederson Akio; Crovella, Sergio; Iseppon, Ana Maria Benko

    2017-01-01

    The discovery of novel plant resistance (R) genes (including their homologs and analogs) opened interesting possibilities for controlling plant diseases caused by several pathogens. However, due to environmental pressure and high selection operated by pathogens, several crop plants have lost specificity, broad-spectrum or durability of resistance. On the other hand, the advances in plant genome sequencing and biotechnological approaches, combined with the increasing knowledge on Rgenes have provided new insights on their applications for plant genetic breeding, allowing the identification and implementation of novel and efficient strategies that enhance or optimize their use for efficiently controlling plant diseases. The present review focuses on main perspectives of application of R-genes and its co-players for the acquisition of resistance to pathogens in cultivated plants, with emphasis on biotechnological inferences, including transgenesis, cisgenesis, directed mutagenesis and gene editing, with examples of success and challenges to be faced. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  17. The molecular basis of disease resistance in higher plants

    African Journals Online (AJOL)

    xxxxxx

    Interactions between disease resistance (R) genes in plants and their corresponding pathogen avirulence (Avr) genes are the key determinants of whether a plant is susceptible or resistance to a pathogen attack. Evidence has emerged that these gene-for-gene interactions in the perception of pathogenic invasions and ...

  18. Plant genome editing made easy: targeted mutagenesis in model and crop plants using the CRISPR/Cas system.

    Science.gov (United States)

    Belhaj, Khaoula; Chaparro-Garcia, Angela; Kamoun, Sophien; Nekrasov, Vladimir

    2013-10-11

    Targeted genome engineering (also known as genome editing) has emerged as an alternative to classical plant breeding and transgenic (GMO) methods to improve crop plants. Until recently, available tools for introducing site-specific double strand DNA breaks were restricted to zinc finger nucleases (ZFNs) and TAL effector nucleases (TALENs). However, these technologies have not been widely adopted by the plant research community due to complicated design and laborious assembly of specific DNA binding proteins for each target gene. Recently, an easier method has emerged based on the bacterial type II CRISPR (clustered regularly interspaced short palindromic repeats)/Cas (CRISPR-associated) immune system. The CRISPR/Cas system allows targeted cleavage of genomic DNA guided by a customizable small noncoding RNA, resulting in gene modifications by both non-homologous end joining (NHEJ) and homology-directed repair (HDR) mechanisms. In this review we summarize and discuss recent applications of the CRISPR/Cas technology in plants.

  19. Blue light requirements for crop plants used in bioregenerative life support systems.

    Science.gov (United States)

    Yorio, N C; Wheeler, R M; Goins, G D; Sanwo-Lewandowski, M M; Mackowiak, C L; Brown, C S; Sager, J C; Stutte, G W

    1998-01-01

    As part of NASA's Advanced Life Support Program, the Breadboard Project at Kennedy Space Center is investigating the feasibility of using crop plants in bioregenerative life support systems (BLSS) for long-duration space missions. Several types of electric lamps have been tested to provide radiant energy for plants in a BLSS. These lamps vary greatly in terms of spectral quality resulting in differences in growth and morphology of the plants tested. Broad spectrum or "white" light sources (e.g., metal halide and fluorescent lamps) provide an adequate spectrum for normal growth and morphology; however, they are not as electrically efficient as are low-pressure sodium (LPS) or high-pressure sodium (HPS) lamps. Although LPS and HPS, as well as the newly tested red light-emitting diodes (LEDs), have good photosynthetically active radiation (PAR) efficiencies, they are deficient in blue light. Results with several of the crops tested for BLSS (wheat, potato, soybean, lettuce, and radish) have shown a minimum amount of blue light (approximately 30 micromoles m-2 s-1) is necessary for normal growth and development. For example, the lack of sufficient blue light in these lamps has resulted in increased stem elongation and significant reductions in photosynthesis and yield. To avoid problems with blue-deficient lamps and maximize yield, sufficient intensity of HPS or blue light supplementation with red LEDs or LPS lamps is required to meet spectral requirements of crops for BLSS.

  20. Improvement of pulse crops through induced mutations: Reconstruction of plant type

    International Nuclear Information System (INIS)

    Rao, C.H.; Tickoo, J.L.; Ram, H.; Jain, H.K.

    1975-01-01

    Many species of grain legumes, because of their cultivation under marginal conditions for centuries, have retained a number of semi-wild characteristics, such as a bushy and spreading growth, which contribute to their adaptability but reduce their yields. The observations presented here indicate that induced mutations may prove effective in generating new plant-types in these crops, which are marked by an improvement in the harvest index and which will show a response to increased plant densities. The present report describes observations on the M 2 progenies of pigeon pea and mung bean on which work has been initiated. (author)

  1. Plant productivity and characterization of zeoponic substrates after three successive crops of radish

    Science.gov (United States)

    Gruener, J. E.; Ming, Doug; Galindo, C., Jr.; Henderson, K. E.

    2006-01-01

    The National Aeronautics and Space Administration (NASA) has developed advanced life support (ALS) systems for long duration space missions that incorporate plants to regenerate the atmosphere (CO2 to O2), recycle water (via evapotranspiration), and produce food. NASA has also developed a zeolite-based synthetic substrate consisting of clinoptilolite and synthetic apatite to support plant growth for ALS systems (Ming et al., 1995). The substrate is called zeoponics and has been designed to slowly release all plant essential elements into "soil" solution. The substrate consists of K- and NH4-exchanged clinoptilolite and a synthetic hydroxyapatite that has Mg, S, and the plant-essential micronutrients incorporated into its structure in addition to Ca and P. Plant performance in zeoponic substrates has been improved by the addition of dolomite pH buffers, nitrifying bacteria, and other calcium-bearing minerals (Henderson et al., 2000; Gruener et al., 2003). Wheat was used as the test crop for all of these studies. The objectives of this study were to expand upon the previous studies to determine the growth and nutrient uptake of radish in zeoponic substrates and to determine the nutrient availability of the zeoponic substrate after three successive radish crops.

  2. Silicon and plant disease resistance against pathogenic fungi.

    Science.gov (United States)

    Fauteux, François; Rémus-Borel, Wilfried; Menzies, James G; Bélanger, Richard R

    2005-08-01

    Silicon (Si) is a bioactive element associated with beneficial effects on mechanical and physiological properties of plants. Silicon alleviates abiotic and biotic stresses, and increases the resistance of plants to pathogenic fungi. Several studies have suggested that Si activates plant defense mechanisms, yet the exact nature of the interaction between the element and biochemical pathways leading to resistance remains unclear. Silicon possesses unique biochemical properties that may explain its bioactivity as a regulator of plant defense mechanisms. It can act as a modulator influencing the timing and extent of plant defense responses in a manner reminiscent of the role of secondary messengers in induced systemic resistance; it can also bind to hydroxyl groups of proteins strategically involved in signal transduction; or it can interfere with cationic co-factors of enzymes influencing pathogenesis-related events. Silicon may therefore interact with several key components of plant stress signaling systems leading to induced resistance.

  3. Rapid Phenotyping Adult Plant Resistance to Stem Rust in Wheat Grown under Controlled Conditions.

    Science.gov (United States)

    Riaz, Adnan; T Hickey, Lee

    2017-01-01

    Stem rust (SR) or black rust caused by Puccinia graminis f. sp. tritici is one of the most common diseases of wheat (Triticum aestivum L.) crops globally. Among the various control measures, the most efficient and sustainable approach is the deployment of genetically resistant cultivars. Traditionally, wheat breeding programs deployed genetic resistance in cultivars, but unknowingly this is often underpinned by a single seedling resistance gene, which is readily overcome by the pathogen. Nowadays, adult plant resistance (APR) is a widely adopted form of rust resistance because more durable mechanisms often underpin it. However, only a handful of SR APR genes are available, so breeders currently strive to combine seedling and APR genes. Phenotyping adult wheat plants for resistance to SR typically involves evaluation in the field. But establishing a rust nursery can be challenging, and screening is limited to once a year. This slows down research efforts to isolate new APR genes and breeding of genetically resistant cultivars.In this study, we report a protocol for rapid evaluation of adult wheat plants for resistance to stem rust. We demonstrate the technique by evaluating a panel of 16 wheat genotypes consisting of near isogenic lines (NILs) for known Sr genes (i.e., Sr2, Sr33, Sr45, Sr50, Sr55, Sr57, and Sr58) and three landraces carrying uncharacterized APR from the N. I. Vavilov Institute of Plant Genetic Resources (VIR). The method can be completed in just 10 weeks and involves two inoculations: first conducted at seedling stage and a second at the adult stage (using the same plants). The technique can detect APR, such as that conferred by APR gene Sr2, along with pseudo-black chaff (the morphological marker). Phenotyping can be conducted throughout the year, and is fast and resource efficient. Further, the phenotyping method can be applied to screen breeding populations or germplasm accessions using local or exotic races of SR.

  4. A review of plant-pharmaceutical interactions: from uptake and effects in crop plants to phytoremediation in constructed wetlands.

    Science.gov (United States)

    Carvalho, Pedro N; Basto, M Clara P; Almeida, C Marisa R; Brix, Hans

    2014-10-01

    Pharmaceuticals are commonly found both in the aquatic and the agricultural environments as a consequence of the human activities and associated discharge of wastewater effluents to the environment. The utilization of treated effluent for crop irrigation, along with land application of manure and biosolids, accelerates the introduction of these compounds into arable lands and crops. Despite the low concentrations of pharmaceuticals usually found, the continuous introduction into the environment from different pathways makes them 'pseudo-persistent'. Several reviews have been published regarding the potential impact of veterinary and human pharmaceuticals on arable land. However, plant uptake as well as phytotoxicity data are scarcely studied. Simultaneously, phytoremediation as a tool for pharmaceutical removal from soils, sediments and water is starting to be researched, with promising results. This review gives an in-depth overview of the phytotoxicity of pharmaceuticals, their uptake and their removal by plants. The aim of the current work was to map the present knowledge concerning pharmaceutical interactions with plants in terms of uptake and the use of plant-based systems for phytoremediation purposes.

  5. Using modern plant breeding to improve the nutritional and technological qualities of oil crops

    Directory of Open Access Journals (Sweden)

    Murphy Denis J.

    2014-11-01

    Full Text Available The last few decades have seen huge advances in our understanding of plant biology and in the development of new technologies for the manipulation of crop plants. The application of relatively straightforward breeding and selection methods made possible the “Green Revolution” of the 1960s and 1970s that effectively doubled or trebled cereal production in much of the world and averted mass famine in Asia. During the 2000s, much attention has been focused on genomic approaches to plant breeding with the deployment of a new generation of technologies, such as marker-assisted selection, next-generation sequencing, transgenesis (genetic engineering or GM and automatic mutagenesis/selection (TILLING, TargetIng Local Lesions IN Genomes. These methods are now being applied to a wide range of crops and have particularly good potential for oil crop improvement in terms of both overall food and non-food yield and nutritional and technical quality of the oils. Key targets include increasing overall oil yield and stability on a per seed or per fruit basis and very high oleic acid content in seed and fruit oils for both premium edible and oleochemical applications. Other more specialised targets include oils enriched in nutritionally desirable “fish oil”-like fatty acids, especially very long chain !-3 acids such as eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA, or increased levels of lipidic vitamins such as carotenoids, tocopherols and tocotrienes. Progress in producing such oils in commercial crops has been good in recent years with several varieties being released or at advanced stages of development.

  6. Accurate measurement of transgene copy number in crop plants using droplet digital PCR.

    Science.gov (United States)

    Collier, Ray; Dasgupta, Kasturi; Xing, Yan-Ping; Hernandez, Bryan Tarape; Shao, Min; Rohozinski, Dominica; Kovak, Emma; Lin, Jeanie; de Oliveira, Maria Luiza P; Stover, Ed; McCue, Kent F; Harmon, Frank G; Blechl, Ann; Thomson, James G; Thilmony, Roger

    2017-06-01

    Genetic transformation is a powerful means for the improvement of crop plants, but requires labor- and resource-intensive methods. An efficient method for identifying single-copy transgene insertion events from a population of independent transgenic lines is desirable. Currently, transgene copy number is estimated by either Southern blot hybridization analyses or quantitative polymerase chain reaction (qPCR) experiments. Southern hybridization is a convincing and reliable method, but it also is expensive, time-consuming and often requires a large amount of genomic DNA and radioactively labeled probes. Alternatively, qPCR requires less DNA and is potentially simpler to perform, but its results can lack the accuracy and precision needed to confidently distinguish between one- and two-copy events in transgenic plants with large genomes. To address this need, we developed a droplet digital PCR-based method for transgene copy number measurement in an array of crops: rice, citrus, potato, maize, tomato and wheat. The method utilizes specific primers to amplify target transgenes, and endogenous reference genes in a single duplexed reaction containing thousands of droplets. Endpoint amplicon production in the droplets is detected and quantified using sequence-specific fluorescently labeled probes. The results demonstrate that this approach can generate confident copy number measurements in independent transgenic lines in these crop species. This method and the compendium of probes and primers will be a useful resource for the plant research community, enabling the simple and accurate determination of transgene copy number in these six important crop species. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  7. Crop systems and plant roots can modify the soil water holding capacity

    Science.gov (United States)

    Doussan, Claude; Cousin, Isabelle; Berard, Annette; Chabbi, Abad; Legendre, Laurent; Czarnes, Sonia; Toussaint, Bruce; Ruy, Stéphane

    2015-04-01

    At the interface between atmosphere and deep sub-soil, the root zone plays a major role in regulating the flow of water between major compartments: groundwater / surface / atmosphere (drainage, runoff, evapotranspiration). This role of soil as regulator/control of water fluxes, but also as a supporting medium to plant growth, is strongly dependent on the hydric properties of the soil. In turn, the plant roots growing in the soil can change its structure; both in the plow layer and in the deeper horizons and, therefore, could change the soil properties, particularly hydric properties. Such root-related alteration of soil properties can be linked to direct effect of roots such as soil perforation during growth, aggregation of soil particles or indirect effects such as the release of exudates by roots that could modify the properties of water or of soil particles. On an another hand, the rhizosphere, the zone around roots influenced by the activity of root and associated microorganisms, could have a high influence on hydric properties, particularly the water retention. To test if crops and plant roots rhizosphere may have a significant effect on water retention, we conducted various experiment from laboratory to field scales. In the lab, we tested different soil and species for rhizospheric effect on soil water retention. Variation in available water content (AWC) between bulk and rhizospheric soil varied from non-significant to a significant increase (to about 16% increase) depending on plant species and soil type. In the field, the alteration of water retention by root systems was tested in different pedological settings for a Maize crop inoculated or not with the bacteria Azospirillum spp., known to alter root structure, growth and morphology. Again, a range of variation in AWC was evidenced, with significant increase (~30%) in some soil types, but more linked to innoculated/non-innoculated plants rather than to a difference between rhizospheric and bulk soil

  8. Drip irrigation in coffee crop under different planting densities: Growth and yield in southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Gleice A. de Assis

    2014-11-01

    Full Text Available Irrigation associated to reduction on planting spaces between rows and between coffee plants has been a featured practice in coffee cultivation. The objective of the present study was to assess, over a period of five consecutive years, influence of different irrigation management regimes and planting densities on growth and bean yield of Coffea arabica L.. The treatments consisted of four irrigation regimes: climatologic water balance, irrigation when the soil water tension reached values close to 20 and 60 kPa; and a control that was not irrigated. The treatments were distributed randomly in five planting densities: 2,500, 3,333, 5,000, 10,000 and 20,000 plants ha-1. A split-plot in randomized block design was used with four replications. Irrigation promoted better growth of coffee plants and increased yield that varied in function of the plant density per area. For densities from 10,000 to 20,000 plants ha-1, regardless of the used irrigation management, mean yield increases were over 49.6% compared to the non-irrigated crop.

  9. Whiteflies: Developing host plant resistance in watermelon from wild sources

    Science.gov (United States)

    The whitefly (Aleyrodidae) Bemisia tabaci causes serious damage to horticultural crops, including watermelon (Citrullus lanatus var. lanatus) and it is known to transmit many plant viruses. This whitefly is highly polyphagous, with over 1,000 known species, and can adapt to the environment. Yet, th...

  10. Allergenicity assessment of Allium sativum leaf agglutinin, a potential candidate protein for developing sap sucking insect resistant food crops.

    Science.gov (United States)

    Mondal, Hossain Ali; Chakraborti, Dipankar; Majumder, Pralay; Roy, Pampa; Roy, Amit; Bhattacharya, Swati Gupta; Das, Sampa

    2011-01-01

    Mannose-binding Allium sativum leaf agglutinin (ASAL) is highly antinutritional and toxic to various phloem-feeding hemipteran insects. ASAL has been expressed in a number of agriculturally important crops to develop resistance against those insects. Awareness of the safety aspect of ASAL is absolutely essential for developing ASAL transgenic plants. Following the guidelines framed by the Food and Agriculture Organization/World Health Organization, the source of the gene, its sequence homology with potent allergens, clinical tests on mammalian systems, and the pepsin resistance and thermostability of the protein were considered to address the issue. No significant homology to the ASAL sequence was detected when compared to known allergenic proteins. The ELISA of blood sera collected from known allergy patients also failed to show significant evidence of cross-reactivity. In vitro and in vivo assays both indicated the digestibility of ASAL in the presence of pepsin in a minimum time period. With these experiments, we concluded that ASAL does not possess any apparent features of an allergen. This is the first report regarding the monitoring of the allergenicity of any mannose-binding monocot lectin having insecticidal efficacy against hemipteran insects.

  11. Crop residue harvest for bioenergy production and its implications on soil functioning and plant growth: A review

    Directory of Open Access Journals (Sweden)

    Maurício Roberto Cherubin

    Full Text Available ABSTRACT: The use of crop residues as a bioenergy feedstock is considered a potential strategy to mitigate greenhouse gas (GHG emissions. However, indiscriminate harvesting of crop residues can induce deleterious effects on soil functioning, plant growth and other ecosystem services. Here, we have summarized the information available in the literature to identify and discuss the main trade-offs and synergisms involved in crop residue management for bioenergy production. The data consistently showed that crop residue harvest and the consequent lower input of organic matter into the soil led to C storage depletions over time, reducing cycling, supply and availability of soil nutrients, directly affecting the soil biota. Although the biota regulates key functions in the soil, crop residue can also cause proliferation of some important agricultural pests. In addition, crop residues act as physical barriers that protect the soil against raindrop impact and temperature variations. Therefore, intensive crop residue harvest can cause soil structure degradation, leading to soil compaction and increased risks of erosion. With regard to GHG emissions, there is no consensus about the potential impact of management of crop residue harvest. In general, residue harvest decreases CO2 and N2O emissions from the decomposition process, but it has no significant effect on CH4 emissions. Plant growth responses to soil and microclimate changes due to crop residue harvest are site and crop specific. Adoption of the best management practices can mitigate the adverse impacts of crop residue harvest. Longterm experiments within strategic production regions are essential to understand and monitor the impact of integrated agricultural systems and propose customized solutions for sustainable crop residue management in each region or landscape. Furthermore, private and public investments/cooperations are necessary for a better understanding of the potential environmental

  12. Simulating Crop Evapotranspiration Response under Different Planting Scenarios by Modified SWAT Model in an Irrigation District, Northwest China

    OpenAIRE

    Liu, Xin; Wang, Sufen; Xue, Han; Singh, Vijay P.

    2015-01-01

    Modelling crop evapotranspiration (ET) response to different planting scenarios in an irrigation district plays a significant role in optimizing crop planting patterns, resolving agricultural water scarcity and facilitating the sustainable use of water resources. In this study, the SWAT model was improved by transforming the evapotranspiration module. Then, the improved model was applied in Qingyuan Irrigation District of northwest China as a case study. Land use, soil, meteorology, irrigatio...

  13. Bipolar resistive switching in different plant and animal proteins

    KAUST Repository

    Bag, A.

    2014-06-01

    We report bipolar resistive switching phenomena observed in different types of plant and animal proteins. Using protein as the switching medium, resistive switching devices have been fabricated with conducting indium tin oxide (ITO) and Al as bottom and top electrodes, respectively. A clockwise bipolar resistive switching phenomenon is observed in all proteins. It is shown that the resistive switching phenomena originate from the local redox process in the protein and the ion exchange from the top electrode/protein interface.

  14. Azolla planting reduces methane emission and nitrogen fertilizer application in double rice cropping system in southern China

    DEFF Research Database (Denmark)

    Xu, Heshui; Zhu, Bo; Liu, Jingna

    2017-01-01

    agronomic benefits. However, the effects of the dual cropping of Azolla on methane emissions of double rice cropping paddies have not yet been reported. Here, we conducted a 3-year field experiment to evaluate the impacts of rice + Azolla on methane emission and rice yield in a double rice cropping system...... with that of the conventional rice cropping with common N fertilizer. Moreover, the rice + Azolla with moderate N fertilizer had the lowest yield-scaled methane (25.2 kg Mg−1 grain yield). Here, we showed for the first time that Azolla planting allows sustainable rice production coupled with methane mitigation in double rice...

  15. Aldo-keto reductase enzymes detoxify glyphosate and improve herbicide resistance in plants.

    Science.gov (United States)

    Vemanna, Ramu S; Vennapusa, Amaranatha Reddy; Easwaran, Murugesh; Chandrashekar, Babitha K; Rao, Hanumantha; Ghanti, Kirankumar; Sudhakar, Chinta; Mysore, Kirankumar S; Makarla, Udayakumar

    2017-07-01

    In recent years, concerns about the use of glyphosate-resistant crops have increased because of glyphosate residual levels in plants and development of herbicide-resistant weeds. In spite of identifying glyphosate-detoxifying genes from microorganisms, the plant mechanism to detoxify glyphosate has not been studied. We characterized an aldo-keto reductase gene from Pseudomonas (PsAKR1) and rice (OsAKR1) and showed, by docking studies, both PsAKR1 and OsAKR1 can efficiently bind to glyphosate. Silencing AKR1 homologues in rice and Nicotiana benthamiana or mutation of AKR1 in yeast and Arabidopsis showed increased sensitivity to glyphosate. External application of AKR proteins rescued glyphosate-mediated cucumber seedling growth inhibition. Regeneration of tobacco transgenic lines expressing PsAKR1 or OsAKRI on glyphosate suggests that AKR can be used as selectable marker to develop transgenic crops. PsAKR1- or OsAKRI-expressing tobacco and rice transgenic plants showed improved tolerance to glyphosate with reduced accumulation of shikimic acid without affecting the normal photosynthetic rates. These results suggested that AKR1 when overexpressed detoxifies glyphosate in planta. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  16. Energy efficiency and energy homeostasis as genetic and epigenetic components of plant performance and crop productivity.

    Science.gov (United States)

    De Block, Marc; Van Lijsebettens, Mieke

    2011-06-01

    The importance of energy metabolism in plant performance and plant productivity is conceptually well recognized. In the eighties, several independent studies in Lolium perenne (ryegrass), Zea mays (maize), and Festuca arundinacea (tall fescue) correlated low respiration rates with high yields. Similar reports in the nineties largely confirmed this correlation in Solanum lycopersicum (tomato) and Cucumis sativus (cucumber). However, selection for reduced respiration does not always result in high-yielding cultivars. Indeed, the ratio between energy content and respiration, defined here as energy efficiency, rather than respiration on its own, has a major impact on the yield potential of a crop. Besides energy efficiency, energy homeostasis, representing the balance between energy production and consumption in a changing environment, also contributes to an enhanced plant performance and this happens mainly through an increased stress tolerance. Although a few single gene approaches look promising, probably whole interacting networks have to be modulated, as is done by classical breeding, to improve the energy status of plants. Recent developments show that both energy efficiency and energy homeostasis have an epigenetic component that can be directed and stabilized by artificial selection (i.e. selective breeding). This novel approach offers new opportunities to improve yield potential and stress tolerance in a wide variety of crops. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Evaluation of Brevibacillus brevis as a potential plant growth promoting rhizobacteria for cotton (Gossypium hirsutum) crop.

    Science.gov (United States)

    Nehra, Vibha; Saharan, Baljeet Singh; Choudhary, Madhu

    2016-01-01

    The present investigation was undertaken to isolate, screen and evaluate a selected promising PGPR Brevibacillus brevis on cotton crop. Out of 156 bacterial isolates one of the most promising isolate was analyzed for the various PGP traits. A seed germination analysis was conducted with cotton seeds to evaluate the potential of the isolate to promote plant growth. The bacterial isolate was checked for its growth and survival at high temperatures. The isolate was also analyzed for the PGP traits exhibited after the heat treatment. To identify the isolate morphological, biochemical and molecular characterization was performed. The isolate was found positive for many of the PGP attributes like IAA, ARA, anti-fungal activity and ammonia production. Effect of seed bacterization on various plant growth parameters was used as an indicator. The isolate showed significant growth and exhibited various PGP traits at high temperature making it suitable as an inoculant for cotton crop. Isolate was identified as Brevibacillus brevis [SVC(II)14] based on phenotypic as well as genotypic attributes and after conducting this research we propose that the B. brevis which is reported for the first time for its PGP potential in cotton, exerts its beneficial effects on cotton crop through combined modes of actions.

  18. Principle and application of plant mutagenesis in crop improvement: a review

    Directory of Open Access Journals (Sweden)

    Yusuff Oladosu

    2016-01-01

    Full Text Available The first step in plant breeding is to identify suitable genotypes containing the desired genes among existing varieties, or to create one if it is not found in nature. In nature, variation occurs mainly as a result of mutations and without it, plant breeding would be impossible. In this context, the major aim in mutation-based breeding is to develop and improve well-adapted plant varieties by modifying one or two major traits to increase their productivity or quality. Both physical and chemical mutagenesis is used in inducing mutations in seeds and other planting materials. Then, selection for agronomic traits is done in the first generation, whereby most mutant lines may be discarded. The agronomic traits are confirmed in the second and third generations through evident phenotypic stability, while other evaluations are carried out in the subsequent generations. Finally, only the mutant lines with desirable traits are selected as a new variety or as a parent line for cross breeding. New varieties derived by induced mutatgenesis are used worldwide: rice in Vietnam, Thailand, China and the United States; durum wheat in Italy and Bulgaria; barley in Peru and European nations; soybean in Vietnam and China; wheat in China; as well as leguminous food crops in Pakistan and India. This paper integrates available data about the impact of mutation breeding-derived crop varieties around the world and highlights the potential of mutation breeding as a flexible and practicable approach applicable to any crop provided that appropriate objectives and selection methods are used.

  19. Genetic engineering of cytokinin metabolism: prospective way to improve agricultural traits of crop plants.

    Science.gov (United States)

    Zalabák, David; Pospíšilová, Hana; Šmehilová, Mária; Mrízová, Katarína; Frébort, Ivo; Galuszka, Petr

    2013-01-01

    Cytokinins (CKs) are ubiquitous phytohormones that participate in development, morphogenesis and many physiological processes throughout plant kingdom. In higher plants, mutants and transgenic cells and tissues with altered activity of CK metabolic enzymes or perception machinery, have highlighted their crucial involvement in different agriculturally important traits, such as productivity, increased tolerance to various stresses and overall plant morphology. Furthermore, recent precise metabolomic analyses have elucidated the specific occurrence and distinct functions of different CK types in various plant species. Thus, smooth manipulation of active CK levels in a spatial and temporal way could be a very potent tool for plant biotechnology in the future. This review summarises recent advances in cytokinin research ranging from transgenic alteration of CK biosynthetic, degradation and glucosylation activities and CK perception to detailed elucidation of molecular processes, in which CKs work as a trigger in model plants. The first attempts to improve the quality of crop plants, focused on cereals are discussed, together with proposed mechanism of action of the responses involved. Copyright © 2011 Elsevier Inc. All rights reserved.

  20. Characterisation of tospovirus resistance in transgenic plants

    NARCIS (Netherlands)

    Prins, M.

    1997-01-01

    Over the past two decades tomato spotted wilt virus (TSWV) has become increasingly important as a pathogen in many crops. This can be attributed to intensified world trade and concomitant spread of one of the most important vectors of the virus, the thrips Frankliniella occidentalis.

  1. Modified cellulose synthase gene from 'Arabidopsis thaliana' confers herbicide resistance to plants

    Energy Technology Data Exchange (ETDEWEB)

    Somerville, Chris R.; Scieble, Wolf

    2000-10-11

    Cellulose synthase ('CS'), a key enzyme in the biosynthesis of cellulose in plants is inhibited by herbicides comprising thiazolidinones such as 5-tert-butyl-carbamoyloxy-3-(3-trifluromethyl) phenyl-4-thiazolidinone (TZ), isoxaben and 2,6-dichlorobenzonitrile (DCB). Two mutant genes encoding isoxaben and TZ-resistant cellulose synthase have been isolated from isoxaben and TZ-resistant Arabidopsis thaliana mutants. When compared with the gene coding for isoxaben or TZ-sensitive cellulose synthase, one of the resistant CS genes contains a point mutation, wherein glycine residue 998 is replaced by an aspartic acid. The other resistant mutation is due to a threonine to isoleucine change at amino acid residue 942. The mutant CS gene can be used to impart herbicide resistance to a plant; thereby permitting the utilization of the herbicide as a single application at a concentration which ensures the complete or substantially complete killing of weeds, while leaving the transgenic crop plant essentially undamaged.

  2. Effect of potassium supply on drought resistance in sorghum: plant growth and macronutrient content

    International Nuclear Information System (INIS)

    Asgharipour, M.R.; Heidari, M.

    2011-01-01

    Nowadays, the main limiting natural resource is widely considered to be water. Therefore, research into crop management practices that enhance drought resistance and plant growth when water supply is limited has become increasingly essential. This study was conducted to evaluate the effect of potassium (K) nutritional status on the drought resistance of grain sorghum during 2009. Drought stress by reducing the yield components, especially the number of panicle per plant and one-hundred grain weight reduced grain yield and greatest yield (3499 kg ha/sup -1/) obtained at full irrigation. Potassium sulfate increased grain and biological yield by 28% and 22%, respectively compared to control through improving growth conditions. Drought stress increased the N content, while reduced water availability decreased the K and Na in plant. No K fertilized plants had the lowest leaf K and N and highest Na concentrations. Chlorophyll content increased significantly with increase in K supply and increased frequency of irrigation. Interaction effect of drought stress and potassium sulfate on all studied traits except chlorophyll content was significant and optimum soil K levels protects plants from drought. These observations indicate that adequate K nutrition can improve drought resistance of sorghum. (author)

  3. The plant characters and corm production of taro as catch crop under the young rubber stands

    Directory of Open Access Journals (Sweden)

    DJUKRI

    2006-07-01

    Full Text Available The research was aimed at revealing the chlorophyll content, leaf area (the plant characters, and the corm production of taro as catch crop under the young rubber stand. This research was conducted by means of Nested Design with nine replication. The intercropping planting used independent variables i.e. N0 (open condition, N1 (under the two-year-old young rubber, and N2 (under the three-year-old young rubber. The dependent variables were the chlorophyll content, leaf area, and production of the taro corm. The parameters investigated were the leaves area, the chlorophyll a and b content, the weight of fresh corm, the weight of dry corm, and the corm production per plots. The research result showed that the leaves area, and the chlorophyll a and b content significantly increased, while the weight of fresh corm, and the weight of dry corm significantly decreased (P<0.05. The fresh corm production per plots under the young rubber two- and three-year-old were significantly decreased compared the control (P<0.05. The intercropping planting or catch crop showed that the taro corm production per plot decreased both of under two- and three-year-old young rubber shades, although the reduction of each clone was significant or not significant, so that tolerant clones could be conserved.

  4. Cryopreservation techniques and their application in vegetatively propagated crop plants in Finland

    Directory of Open Access Journals (Sweden)

    A. NUKARI

    2008-12-01

    Full Text Available Cryopreservation protocols have been introduced as techniques for germplasm preservation of vegetatively propagated horticultural and staple food crops. In Finland, cryopreservation has been studied since 1990’s, beginning with cryopreservation of forest tree breeding material and since 2004 on cryopreservation of genetic resources of horticultural plants and potato. Priority was given to cryopreservation of raspberry (Rubus ideaus L., strawberry (Fragaria x ananassa Duch. and potato (Solanum tuberosum L. and the possibility to use cryotherapy in eradication of raspberry bushy dwarf virus (RBDV from in vitro cultures were studied on raspberry. Modified droplet vitrification cryopreservation protocols were designed for raspberry and strawberry and cryotherapy combined with thermotherapy was proven to be a successful application to eliminate RBDV from infected raspberries. Cryotherapy method can be applied for a large scale elimination of viruses from plant germplasm and from candidate nuclear stock in a certified plant production scheme. Routine use of cryotechniques in germplasm preservation of vegetatively propagated horticultural plants was started. Besides for long term germplasm preservation, cryopreservation techniques can be applied also for maintenance of mother stocks in certified plant production schemes and in commercial plant production. Cryopreservation of potato shoot tips needs additional detailed research to obtain sufficient recovery and regrowth rates.;

  5. Brassinosteroids play a critical role in the regulation of pesticide metabolism in crop plants.

    Science.gov (United States)

    Zhou, Yanhong; Xia, Xiaojian; Yu, Gaobo; Wang, Jitao; Wu, Jingxue; Wang, Mengmeng; Yang, Youxin; Shi, Kai; Yu, Yunlong; Chen, Zhixiang; Gan, Jay; Yu, Jingquan

    2015-03-12

    Pesticide residues in agricultural produce pose a threat to human health worldwide. Although the detoxification mechanisms for xenobiotics have been extensively studied in mammalian cells, information about the regulation network in plants remains elusive. Here we show that brassinosteroids (BRs), a class of natural plant hormones, decreased residues of common organophosphorus, organochlorine and carbamate pesticides by 30-70% on tomato, rice, tea, broccoli, cucumber, strawberry, and other plants when treated externally. Genome-wide microarray analysis showed that fungicide chlorothalonil (CHT) and BR co-upregulated 301 genes, including a set of detoxifying genes encoding cytochrome P450, oxidoreductase, hydrolase and transferase in tomato plants. The level of BRs was closely related to the respiratory burst oxidase 1 (RBOH1)-encoded NADPH oxides-dependent H2O2 production, glutathione biosynthesis and the redox homeostasis, and the activity of glutathione S-transferase (GST). Gene silencing treatments showed that BRs decreased pesticide residues in plants likely by promoting their metabolism through a signaling pathway involving BRs-induced H2O2 production and cellular redox change. Our study provided a novel approach for minimizing pesticide residues in crops by exploiting plants' own detoxification mechanisms.

  6. Small RNAs in plants: Recent development and application for crop improvement

    OpenAIRE

    Ayushi eKamthan; Abira eChaudhuri; Mohan eKamthan; Asis eDatta

    2015-01-01

    The phenomenon of RNA interference (RNAi) which involves sequence-specific gene regulation by small non-coding RNAs, i.e., small interfering RNA (siRNA) and microRNA (miRNA) has emerged as one of most powerful approaches for crop improvement. RNAi based on siRNA is one of the widely used tools of reverse genetics which aid in revealing gene functions in many species. This technology has been extensively applied to alter the gene expression in plants with an aim to achieve desirable traits. RN...

  7. Alelopatia de cultivos de cobertura vegetal sobre plantas infestantes = Allelopathy of cover crop on weed plants

    Directory of Open Access Journals (Sweden)

    Luciene Kazue Tokura

    2006-07-01

    Full Text Available O presente trabalho avaliou o potencial alelopático de cultivos de cobertura vegetal de trigo, aveia preta, milheto, nabo forrageiro e colza sobre o desenvolvimento de plantas infestantes e verificou qual das coberturas vegetais exerce maior controle sobre as mesmas. Os cultivos de cobertura vegetal foram implantados sob preparo convencional (uma aração e uma gradagem no Núcleo Experimental de Engenharia Agrícola (NEEA, da Universidade Estadual do Oeste do Paraná (Unioeste, Cascavel, Estado do Paraná. Mensalmente, realizou-se o acompanhamento e identificação das plantas infestantes emersas nas áreas de cobertura vegetal no período de agosto de 2000 a agosto de 2001. Os resultados obtidos permitiram concluir que das espécies encontradas, o capim marmelada foi o que apresentou maior potencial alelopático e a erva-de-santa-maria o menor. As coberturasvegetais que apresentaram melhor controle do total de plantas infestantes presentes na área experimental, incluindo àquelas com reconhecido potencial alelopático, foram aveia preta, colza, nabo forrageiro e milheto.This work evaluated the cover crop allelopathic potential of wheat, black oat, pearl millet, turnip and rape on the development of weed plants. It also verified which cover crop has larger control on the weed plants. The cover crop was implanted under conventional tillage (one disk plowing plus one disk harrowing in the Experimental Nucleus of Agricultural Engineering (NEEA, of the State University of the West of Paraná (Unioeste, Cascavel, Paraná State. Monthly (from August 2000 to August 2001, weed plants identification in the cover crop area was made. Results showed that from the found species, the alexander grass was the one that presented larger allelopathic potential, and, the mexican-tea was the one that presented smaller control. The vegetable coverings that presented larger control of the total of weed plants in the experimental area, including those with

  8. Role of the plant cell wall in gravity resistance.

    Science.gov (United States)

    Hoson, Takayuki; Wakabayashi, Kazuyuki

    2015-04-01

    Gravity resistance, mechanical resistance to the gravitational force, is a principal graviresponse in plants, comparable to gravitropism. The cell wall is responsible for the final step of gravity resistance. The gravity signal increases the rigidity of the cell wall via the accumulation of its constituents, polymerization of certain matrix polysaccharides due to the suppression of breakdown, stimulation of cross-link formation, and modifications to the wall environment, in a wide range of situations from microgravity in space to hypergravity. Plants thus develop a tough body to resist the gravitational force via an increase in cell wall rigidity and the modification of growth anisotropy. The development of gravity resistance mechanisms has played an important role in the acquisition of responses to various mechanical stresses and the evolution of land plants. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Mechanisms and evolution of plant resistance to aphids.

    Science.gov (United States)

    Züst, Tobias; Agrawal, Anurag A

    2016-01-06

    Aphids are important herbivores of both wild and cultivated plants. Plants rely on unique mechanisms of recognition, signalling and defence to cope with the specialized mode of phloem feeding by aphids. Aspects of the molecular mechanisms underlying aphid-plant interactions are beginning to be understood. Recent advances include the identification of aphid salivary proteins involved in host plant manipulation, and plant receptors involved in aphid recognition. However, a complete picture of aphid-plant interactions requires consideration of the ecological outcome of these mechanisms in nature, and the evolutionary processes that shaped them. Here we identify general patterns of resistance, with a special focus on recognition, phytohormonal signalling, secondary metabolites and induction of plant resistance. We discuss how host specialization can enable aphids to co-opt both the phytohormonal responses and defensive compounds of plants for their own benefit at a local scale. In response, systemically induced resistance in plants is common and often involves targeted responses to specific aphid species or even genotypes. As co-evolutionary adaptation between plants and aphids is ongoing, the stealthy nature of aphid feeding makes both the mechanisms and outcomes of these interactions highly distinct from those of other herbivore-plant interactions.

  10. Plant agricultural streptomycin formulations do not carry antibiotic resistance genes.

    Science.gov (United States)

    Rezzonico, Fabio; Stockwell, Virginia O; Duffy, Brion

    2009-07-01

    Streptomycin is used in plant agriculture for bacterial disease control, particularly against fire blight in pome fruit orchards. Concerns that this may increase environmental antibiotic resistance have led to bans or restrictions on use. Experience with antibiotic use in animal feeds raises the possible influence of formulation-delivered resistance genes. We demonstrate that agricultural streptomycin formulations do not carry producer organism resistance genes. By using an optimized extraction procedure, Streptomyces 16S rRNA genes and the streptomycin resistance gene strA were not detected in agricultural streptomycin formulations. This diminishes the likelihood for one potential factor in resistance development due to streptomycin use.

  11. Plant-generated artificial small RNAs mediated aphid resistance.

    Directory of Open Access Journals (Sweden)

    Hongyan Guo

    Full Text Available BACKGROUND: RNA silencing is an important mechanism for regulation of endogenous gene expression and defense against genomic intruders in plants. This natural defense system was adopted to generate virus-resistant plants even before the mechanism of RNA silencing was unveiled. With the clarification of that mechanism, transgenic antiviral plants were developed that expressed artificial virus-specific hairpin RNAs (hpRNAs or microRNAs (amiRNAs in host plants. Previous works also showed that plant-mediated RNA silencing technology could be a practical method for constructing insect-resistant plants by expressing hpRNAs targeting essential genes of insects. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we chose aphid Myzus persicae of order Hemiptera as a target insect. To screen for aphid genes vulnerable to attack by plant-mediated RNA silencing to establish plant aphid resistance, we selected nine genes of M. persicae as silencing targets, and constructed their hpRNA-expressing vectors. For the acetylcholinesterase 2 coding gene (MpAChE2, two amiRNA-expressing vectors were also constructed. The vectors were transformed into tobacco plants (Nicotiana tabacum cv. Xanti. Insect challenge assays showed that most of the transgenic plants gained aphid resistance, among which those expressing hpRNAs targeting V-type proton ATPase subunit E-like (V-ATPaseE or tubulin folding cofactor D (TBCD genes displayed stronger aphicidal activity. The transgenic plants expressing amiRNAs targeting two different sites in the MpAChE2 gene exhibited better aphid resistance than the plants expressing MpAChE2-specific hpRNA. CONCLUSIONS/SIGNIFICANCE: Our results indicated that plant-mediated insect-RNA silencing might be an effective way to develop plants resistant to insects with piercing-sucking mouthparts, and both the selection of vulnerable target genes and the biogenetic type of the small RNAs were crucial for the effectiveness of aphid control. The expression of

  12. Chemical control of perennial and annual weeds in herbicide resistant soybean crops.

    Science.gov (United States)

    Sarpe, N; Roibu, C; Negrila, E; Bodescu, F; Fuia, S; Popa, C; Beraru, C

    2001-01-01

    In Romania, the first tests with Roundup Ready on soybean crops were performed in 1998, on 2 soil types: a) at Teleorman Station on chernozem containing 3.5% humus, 4.5% clay b) at Brăila Station placed in Danube Meadow on alluvial soil containing 3.90% humus and 46% clay. In every locality cultivated soybean cultivar S.2254 was resistant to glyphosate. During the three years of experiments (1998-2000) the crop of soybean was infested with various species of weeds (both annual and perennial) of which the most important are: Sorghum halepense (60-80%), Echinochloa crus-galli, Setaria glauca, Amaranthus retroflexus, Solarium nigrum, Yanthium italicum, Abutilon theoprasthi, Sinapis arvensis, Datum stramonium, Polygonum persicaria, Calystegia sepium, Cirsium arvense. In 3 years of experience the best weed control and the highest soybean production were obtained in the variants treated 2 times postemergent with Roundup Ready at a dose of 3 + 3 l/ha. Similar results were also obtained in the farms of the Academy of Agricultural Forestry Sciences, where GMO soybean was cultivated on 1500 hectares.

  13. Resistance evolution to Bt crops: predispersal mating of European corn borers.

    Directory of Open Access Journals (Sweden)

    Ambroise Dalecky

    2006-06-01

    Full Text Available Over the past decade, the high-dose refuge (HDR strategy, aimed at delaying the evolution of pest resistance to Bacillus thuringiensis (Bt toxins produced by transgenic crops, became mandatory in the United States and is being discussed for Europe. However, precopulatory dispersal and the mating rate between resident and immigrant individuals, two features influencing the efficiency of this strategy, have seldom been quantified in pests targeted by these toxins. We combined mark-recapture and biogeochemical marking over three breeding seasons to quantify these features directly in natural populations of Ostrinia nubilalis, a major lepidopteran corn pest. At the local scale, resident females mated regardless of males having dispersed beforehand or not, as assumed in the HDR strategy. Accordingly, 0-67% of resident females mating before dispersal did so with resident males, this percentage depending on the local proportion of resident males (0% to 67.2%. However, resident males rarely mated with immigrant females (which mostly arrived mated, the fraction of females mating before dispersal was variable and sometimes substantial (4.8% to 56.8%, and there was no evidence for male premating dispersal being higher. Hence, O. nubilalis probably mates at a more restricted spatial scale than previously assumed, a feature that may decrease the efficiency of the HDR strategy under certain circumstances, depending for example on crop rotation practices.

  14. Cucumber plants (cucumis sativus l.) growth and crop yield of chicken manure fertilized with plant spacing

    Science.gov (United States)

    Pratiwi Aritonang, Sri; Panjaitan, Ernitha; Parsaulian Tondang, Fetrus

    2018-03-01

    The research was conducted in Tanjung Sari, Kecamatan Medan Selayang Kotamadya Medan ± 32 meters above sea level. It started since July 2016 to September 2016. It was designed with randomization block design with two factorial experiments which are chicken manure and plant spacing. First factor was 4 doses of chicken manure, symbolized by K; K0 = 1.5 kg/plot, K1 = 2 kg/plot, K2 = 2.5 kg/plot and K3 = 3 kg/plot. Second was 4 different plant spacing, symbolized by J; J0 = 30 cm x 60 cm, J1 =: 35 cm x 60 cm, J2 = 40 cm x 60 cm and J3 = 45 cm x 60 cm. The result shows that giving 3kg/plot of chicken manure increases plant height to 162.15 cm with 22.44 number of leaves. Fresh fruits per sample was weight 1121.88 g and per plot is 4.52 kg with 9.17 and 36.67 units of fruits per sample and plot respectively. With 45 cm x 60 cm (J3) for plant spacing gives a plant with the height of 160.51 cm and 22.85 number of leaves. Fresh fruits obtained is 1216.67 g and 9.33 units per sample while per plot gives 4.90 kg and 7.33 units of fresh fruits. This plant spacing leads to a better output for the yield compared to narrower spacing. There are no interaction between chicken manure dosage and plant spacing towards plant height, number of leaves, fresh fruits weight and units per sample and plot.

  15. Effect of planting density on root lodging resistance and its relationship to nodal root growth characteristics in maize (Zea mays L.)

    DEFF Research Database (Denmark)

    Liu, Shengqun; Song, Fengbin; Liu, Fulai

    2012-01-01

    Increase of planting density has been widely used to increase grain yield in maize. However, it may lead to higher risk of root lodging hence causing significant yield loss of the crop. The objective of this study was to investigate the effect of planting density on maize nodal root growth...... characteristics and to analyse their relationships to root lodging resistance. Field experiment was conducted in 2010 and 2011, using two maize varieties, Zhengdan 958 (ZD) and Xianyu 335 (XY), under three planting densities, viz., 4.50, 8.25 and 12.00 plants m-2. The results showed the root failure moment......, an indicator of root lodging resistance, was significantly affected by the planting density, the maize variety, as well as the crop developmental stages, and was decreased with increasing planting density. The number and the average diameter of the roots on the upper internodes (phytomer 5 to 8) were decreased...

  16. Antibiotic resistance plasmids in wastewater treatment plants and ...

    African Journals Online (AJOL)

    Antibiotic resistance plasmids found in wastewater treatment plants (WWTPs) may represent a threat to public health if they are readily disseminated into the environment and ultimately into pathogenic bacteria. The wastewater environments provide an ideal ecosystem for development and evolution of antibiotic resistance ...

  17. Editing plants for virus resistance using CRISPR-Cas.

    Science.gov (United States)

    Green, J C; Hu, J S

    This minireview summarizes recent advancements using the clustered regularly interspaced palindromic repeats-associated nuclease systems (CRISPR-Cas) derived from prokaryotes to breed plants resistant to DNA and RNA viruses. The CRISPR-Cas system represents a powerful tool able to edit and insert novel traits into plants precisely at chosen loci offering enormous advantages to classical breeding. Approaches to engineering plant virus resistance in both transgenic and non-transgenic plants are discussed. Iterations of the CRISPR-Cas system, FnCas9 and C2c2 capable of editing RNA in eukaryotic cells offer a particular advantage for providing resistance to RNA viruses which represent the great majority of known plant viruses. Scientists have obtained conflicting results using gene silencing technology to produce transgenic plants resistant to geminiviruses. CRISPR-Cas systems engineered in plants to target geminiviruses have consistently reduced virus accumulation providing increased resistance to virus infection. CRISPR-Cas may provide novel and reliable approaches to control geminiviruses and other ssDNA viruses such as Banana bunchy top virus (BBTV).

  18. Plant Agricultural Streptomycin Formulations Do Not Carry Antibiotic Resistance Genes▿

    OpenAIRE

    Rezzonico, Fabio; Stockwell, Virginia O.; Duffy, Brion

    2009-01-01

    Streptomycin is used in plant agriculture for bacterial disease control, particularly against fire blight in pome fruit orchards. Concerns that this may increase environmental antibiotic resistance have led to bans or restrictions on use. Experience with antibiotic use in animal feeds raises the possible influence of formulation-delivered resistance genes. We demonstrate that agricultural streptomycin formulations do not carry producer organism resistance genes. By using an optimized extracti...

  19. Introgression of Physiological Traits for a Comprehensive Improvement of Drought Adaptation in Crop Plants

    Directory of Open Access Journals (Sweden)

    Sheshshayee M. Sreeman

    2018-04-01

    Full Text Available Burgeoning population growth, industrial demand, and the predicted global climate change resulting in erratic monsoon rains are expected to severely limit fresh water availability for agriculture both in irrigated and rainfed ecosystems. In order to remain food and nutrient secure, agriculture research needs to focus on devising strategies to save water in irrigated conditions and to develop superior cultivars with improved water productivity to sustain yield under rainfed conditions. Recent opinions accruing in the scientific literature strongly favor the adoption of a “trait based” crop improvement approach for increasing water productivity. Traits associated with maintenance of positive tissue turgor and maintenance of increased carbon assimilation are regarded as most relevant to improve crop growth rates under water limiting conditions and to enhance water productivity. The advent of several water saving agronomic practices notwithstanding, a genetic enhancement strategy of introgressing distinct physiological, morphological, and cellular mechanisms on to a single elite genetic background is essential for achieving a comprehensive improvement in drought adaptation in crop plants. The significant progress made in genomics, though would provide the necessary impetus, a clear understanding of the “traits” to be introgressed is the most essential need of the hour. Water uptake by a better root architecture, water conservation by preventing unproductive transpiration are crucial for maintaining positive tissue water relations. Improved carbon assimilation associated with carboxylation capacity and mesophyll conductance is important in sustaining crop growth rates under water limited conditions. Besides these major traits, we summarize the available information in literature on classifying various drought adaptive traits. We provide evidences that Water-Use Efficiency when introgressed with moderately higher transpiration, would

  20. Long term growth of crop plants on experimental plots created among slag heaps.

    Science.gov (United States)

    Halecki, Wiktor; Klatka, Sławomir

    2018-01-01

    Suppression of plant growth is a common problem in post-mining reclaimed areas, as coarse texture of soils may increase nitrate leaching. Assessing feasibility of using solid waste (precipitated solid matter) produced by water and sewage treatment processes in field conditions is very important in mine soil reclamation. Our work investigated the possibility of plant growth in a degraded site covered with sewage-derived sludge material. A test area (21m × 18m) was established on a mine soil heap. Experimental plant species included Camelina sativa, Helianthus annuus, Festuca rubra, Miscanthus giganteus, Amaranthus cruentus, Brassica napus, Melilotus albus, Beta vulgaris, and Zea mays. ANOVA showed sufficient water content and acceptable physical properties of the soil in each year and layer in a multi-year period, indicating that these species were suitable for phytoremediation purposes. Results of trace elements assays indicated low degree of contamination caused by Carbocrash waste material and low potential ecological risk for all plant species. Detrended correspondence analysis revealed that total porosity and capillary porosity were the most important variables for the biosolids among all water content related properties. Overall, crop plants were found useful on heavily degraded land and the soil benefited from their presence. An addition of Carbocrash substrate to mine soil improved the initial stage of soil reclamation and accelerated plant growth. The use of this substrate in phytoremediation helped to balance the content of nutrients, promoted plant growth, and increased plant tolerance to salinity. Sewage sludge-amended biosolids may be applied directly to agricultural soil, not only in experimental conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Genotoxic stress and DNA repair in plants: emerging functions and tools for improving crop productivity.

    Science.gov (United States)

    Balestrazzi, Alma; Confalonieri, Massimo; Macovei, Anca; Donà, Mattia; Carbonera, Daniela

    2011-03-01

    Crop productivity is strictly related to genome stability, an essential requisite for optimal plant growth/development. Genotoxic agents (e.g., chemical agents, radiations) can cause both chemical and structural damage to DNA. In some cases, they severely affect the integrity of plant genome by inducing base oxidation, which interferes with the basal processes of replication and transcription, eventually leading to cell death. The cell response to oxidative stress includes several DNA repair pathways, which are activated to remove the damaged bases and other lesions. Information concerning DNA repair in plants is still limited, although results from gene profiling and mutant analysis suggest possible differences in repair mechanisms between plants and other eukaryotes. The present review focuses on the base- and nucleotide excision repair (BER, NER) pathways, which operate according to the most common DNA repair rule (excision of damaged bases and replacement by the correct nucleotide), highlighting the most recent findings in plants. An update on DNA repair in organelles, chloroplasts and mitochondria is also provided. Finally, it is generally acknowledged that DNA repair plays a critical role during seed imbibition, preserving seed vigor. Despite this, only a limited number of studies, described here, dedicated to seeds are currently available.

  2. Uptake and translocation of Ti from nanoparticles in crops and wetland plants.

    Science.gov (United States)

    Jacob, Donna L; Borchardt, Joshua D; Navaratnam, Leelaruban; Otte, Marinus L; Bezbaruah, Achintya N

    2013-01-01

    Bioavailability of engineered metal nanoparticles affects uptake in plants, impacts on ecosystems, and phytoremediation. We studied uptake and translocation of Ti in plants when the main source of this metal was TiO2 nanoparticles. Two crops (Phaseolus vulgaris (bean) and Triticum aestivum (wheat)), a wetland species (Rumex crispus, curly dock), and the floating aquatic plant (Elodea canadensis, Canadian waterweed), were grown in nutrient solutions with TiO2 nanoparticles (0, 6, 18 mmol Ti L(-1) for P. vulgaris, T. aestivum, and R. crispus; and 0 and 12 mmol Ti L(-1) for E. canadensis). Also examined in E. canadensis was the influence of TiO2 nanoparticles upon the uptake of Fe, Mn, and Mg, and the influence of P on Ti uptake. For the rooted plants, exposure to TiO2 nanoparticles did not affect biomass production, but significantly increased root Ti sorption and uptake. R. crispus showed translocation of Ti into the shoots. E. canadensis also showed significant uptake of Ti, P in the nutrient solution significantly decreased Ti uptake, and the uptake patterns of Mn and Mg were altered. Ti from nano-Ti was bioavailable to plants, thus showing the potential for cycling in ecosystems and for phytoremediation, particularly where water is the main carrier.

  3. Ethnobotany of food plants in the high river Ter valley (Pyrenees, Catalonia, Iberian Peninsula): non-crop food vascular plants and crop food plants with medicinal properties.

    Science.gov (United States)

    Rigat, Montse; Bonet, Maria Àngels; Garcia, Sònia; Garnatje, Teresa; Vallès, Joan

    2009-01-01

    The present study reports a part of the findings of an ethnobotanical research project conducted in the Catalan region of the high river Ter valley (Iberian Peninsula), concerning the use of wild vascular plants as food and the medicinal uses of both wild and cultivated food plants. We have detected 100 species which are or have been consumed in this region, 83 of which are treated here (the remaining are the cultivated food plants without additional medicinal uses). Some of them, such as Achillea ptarmica subsp. pyrenaica, Convolvulus arvensis, Leontodon hispidus, Molopospermum peloponnesiacum and Taraxacum dissectum, have not been previously reported, or have only very rarely been cited or indicated as plant foods in very restricted geographical areas. Several of these edible wild plants have a therapeutic use attributed to them by local people, making them a kind of functional food. They are usually eaten raw, dressed in salads or cooked; the elaboration of products from these species such as liquors or marmalades is a common practice in the region. The consumption of these resources is still fairly alive in popular practice, as is the existence of homegardens, where many of these plants are cultivated for private consumption.

  4. Use of crop water stress index for monitoring water stress in some sinanthropic plant species

    Directory of Open Access Journals (Sweden)

    Marinela Roxana ROŞESCU

    2010-11-01

    Full Text Available The water stress indicator (crop water stress index, CWSI is a measure of the transpiration rate of a plant, influenced by the leaf and air temperature difference from the plant’s vicinity and the air pressure deficit of the water vapors from the atmosphere. The experiments were realized in July-August 2008 and 2009 for six species in the cities Pitesti, Mioveni and Maracineni: Cichorium intybus L., Conyza canadensis (L. Cronq., Erigeron annuus L. (Pers., Lactuca serriola Torn., Polygonum aviculare L. and Echinochloa crus-galli (L. Beauv. For those species we calculated the CWSI to estimate the water stress on the selected plants in the urban environment conditions. The analyzed species were exposed to a less accentuated water stress while vegetating in the soil and to a more intense one they were grown in the asphalt cracks. Cichorium intybus had the smallest CWSI value (0.26 while Lactuca serriola the highest one (0.44.

  5. Milestones in plant sulfur research on sulfur-induced-resistance (SIR in Europe

    Directory of Open Access Journals (Sweden)

    Elke eBloem

    2015-01-01

    Full Text Available Until the 1970´s of the last century sulfur (S was mainly regarded as a pollutant being the main contributor of acid rain, causing forest dieback in central Europe. When Clean Air Acts came into force at the start of the 1980´s SO2 contaminations in the air were consequently reduced within the next years. S changed from an unwanted pollutant into a lacking plant nutrient in agriculture since agricultural fields were no longer fertilized indirectly by industrial pollution. S deficiency was first noticed in Brassica crops that display an especially high S demand because of its content of S-containing secondary metabolites, the glucosinolates. In Scotland, where S depositions decreased even faster than in continental Europe, an increasing disease incidence with Pyrenopeziza brassicae was observed in oilseed rape in the beginning 1990´s and the concept of sulfur-induced-resistance (SIR was developed after a relationship between the S status and the disease incidence was uncovered. Since then a lot of research was carried out to unravel the background of SIR in the metabolism of agricultural crops and to identify metabolites, enzymes and reactions, which are potentially activated by the S metabolism to combat fungal pathogens. The S status of the crop is affecting many different plant features such as color and scent of flowers, pigments in leaves, metabolite concentrations and the release of gaseous S compounds which are directly influencing the desirability of a crop for a variety of different organisms from microorganisms, over insects and slugs to the point of grazing animals.The present paper is an attempt to sum up the knowledge about the effect of the S nutritional status of agricultural crops on parameters that are directly related to their health status and by this to SIR. Milestones in SIR research are compiled, open questions are addressed and future projections were developed.

  6. Phosphorylation and proteome dynamics in pathogen-resistant tomato plants

    NARCIS (Netherlands)

    Stulemeijer, I.J.E.

    2008-01-01

    Microbial plant pathogens impose a continuous threat on global food production. Similar to disease resistance in mammals, an innate immune system allows plants to recognise pathogens and swiftly activate defence. For the work described in this thesis, the interaction between tomato and the

  7. Plant resistance to cold stress: Mechanisms and environmental ...

    Indian Academy of Sciences (India)

    Unknown

    temperature was an even more effective signal than day-length. [Beck E H, Heim R and Hansen J 2004 Plant resistance to cold stress: Mechanisms and environmental signals triggering frost hardening and dehardening; J. Biosci. 29 449–459]. 1. Introduction. 1.1 Ecophysiological aspects of plant cold stress and acclimation.

  8. Biotechnological approaches to determine the impact of viruses in the energy crop plant Jatropha curcas

    Science.gov (United States)

    2011-01-01

    Background Geminiviruses infect a wide range of plant species including Jatropha and cassava both belonging to family Euphorbiaceae. Cassava is traditionally an important food crop in Sub - Saharan countries, while Jatropha is considered as valuable biofuel plant with great perspectives in the future. Results A total of 127 Jatropha samples from Ethiopia and Kenya and 124 cassava samples from Kenya were tested by Enzyme-Linked Immunosorbent Assay (ELISA) for RNA viruses and polymerase chain reaction for geminiviruses. Jatropha samples from 4 different districts in Kenya and Ethiopia (analyzed by ELISA) were negative for all three RNA viruses tested: Cassava brown streak virus (CBSV), Cassava common mosaic virus, Cucumber mosaic virus, Three cassava samples from Busia district (Kenya) contained CBSV. Efforts to develop diagnostic approaches allowing reliable pathogen detection in Jatropha, involved the amplification and sequencing of the entire DNA A molecules of 40 Kenyan isolates belonging to African cassava mosaic virus (ACMV) and East African cassava mosaic virus - Uganda. This information enabled the design of novel primers to address different questions: a) primers amplifying longer sequences led to a phylogenetic tree of isolates, allowing some predictions on the evolutionary aspects of Begomoviruses in Jatrophia; b) primers amplifying shorter sequences represent a reliable diagnostic tool. This is the first report of the two Begomoviruses in J. curcas. Two cassava samples were co - infected with cassava mosaic geminivirus and CBSV. A Defective DNA A of ACMV was found for the first time in Jatropha. Conclusion Cassava geminiviruses occurring in Jatropha might be spread wider than anticipated. If not taken care of, this virus infection might negatively impact large scale plantations for biofuel production. Being hosts for similar pathogens, the planting vicinity of the two crop plants needs to be handled carefully. PMID:21812981

  9. Biotechnological approaches to determine the impact of viruses in the energy crop plant Jatropha curcas

    Directory of Open Access Journals (Sweden)

    Maghuly Fatemeh

    2011-08-01

    Full Text Available Abstract Background Geminiviruses infect a wide range of plant species including Jatropha and cassava both belonging to family Euphorbiaceae. Cassava is traditionally an important food crop in Sub - Saharan countries, while Jatropha is considered as valuable biofuel plant with great perspectives in the future. Results A total of 127 Jatropha samples from Ethiopia and Kenya and 124 cassava samples from Kenya were tested by Enzyme-Linked Immunosorbent Assay (ELISA for RNA viruses and polymerase chain reaction for geminiviruses. Jatropha samples from 4 different districts in Kenya and Ethiopia (analyzed by ELISA were negative for all three RNA viruses tested: Cassava brown streak virus (CBSV, Cassava common mosaic virus, Cucumber mosaic virus, Three cassava samples from Busia district (Kenya contained CBSV. Efforts to develop diagnostic approaches allowing reliable pathogen detection in Jatropha, involved the amplification and sequencing of the entire DNA A molecules of 40 Kenyan isolates belonging to African cassava mosaic virus (ACMV and East African cassava mosaic virus - Uganda. This information enabled the design of novel primers to address different questions: a primers amplifying longer sequences led to a phylogenetic tree of isolates, allowing some predictions on the evolutionary aspects of Begomoviruses in Jatrophia; b primers amplifying shorter sequences represent a reliable diagnostic tool. This is the first report of the two Begomoviruses in J. curcas. Two cassava samples were co - infected with cassava mosaic geminivirus and CBSV. A Defective DNA A of ACMV was found for the first time in Jatropha. Conclusion Cassava geminiviruses occurring in Jatropha might be spread wider than anticipated. If not taken care of, this virus infection might negatively impact large scale plantations for biofuel production. Being hosts for similar pathogens, the planting vicinity of the two crop plants needs to be handled carefully.

  10. The genome of the recently domesticated crop plant sugar beet (Beta vulgaris).

    Science.gov (United States)

    Dohm, Juliane C; Minoche, André E; Holtgräwe, Daniela; Capella-Gutiérrez, Salvador; Zakrzewski, Falk; Tafer, Hakim; Rupp, Oliver; Sörensen, Thomas Rosleff; Stracke, Ralf; Reinhardt, Richard; Goesmann, Alexander; Kraft, Thomas; Schulz, Britta; Stadler, Peter F; Schmidt, Thomas; Gabaldón, Toni; Lehrach, Hans; Weisshaar, Bernd; Himmelbauer, Heinz

    2014-01-23

    Sugar beet (Beta vulgaris ssp. vulgaris) is an important crop of temperate climates which provides nearly 30% of the world's annual sugar production and is a source for bioethanol and animal feed. The species belongs to the order of Caryophylalles, is diploid with 2n = 18 chromosomes, has an estimated genome size of 714-758 megabases and shares an ancient genome triplication with other eudicot plants. Leafy beets have been cultivated since Roman times, but sugar beet is one of the most recently domesticated crops. It arose in the late eighteenth century when lines accumulating sugar in the storage root were selected from crosses made with chard and fodder beet. Here we present a reference genome sequence for sugar beet as the first non-rosid, non-asterid eudicot genome, advancing comparative genomics and phylogenetic reconstructions. The genome sequence comprises 567 megabases, of which 85% could be assigned to chromosomes. The assembly covers a large proportion of the repetitive sequence content that was estimated to be 63%. We predicted 27,421 protein-coding genes supported by transcript data and annotated them on the basis of sequence homology. Phylogenetic analyses provided evidence for the separation of Caryophyllales before the split of asterids and rosids, and revealed lineage-specific gene family expansions and losses. We sequenced spinach (Spinacia oleracea), another Caryophyllales species, and validated features that separate this clade from rosids and asterids. Intraspecific genomic variation was analysed based on the genome sequences of sea beet (Beta vulgaris ssp. maritima; progenitor of all beet crops) and four additional sugar beet accessions. We identified seven million variant positions in the reference genome, and also large regions of low variability, indicating artificial selection. The sugar beet genome sequence enables the identification of genes affecting agronomically relevant traits, supports molecular breeding and maximizes the plant

  11. Enhanced methanol production in plants provides broad spectrum insect resistance.

    Directory of Open Access Journals (Sweden)

    Sameer Dixit

    Full Text Available Plants naturally emit methanol as volatile organic compound. Methanol is toxic to insect pests; but the quantity produced by most of the plants is not enough to protect them against invading insect pests. In the present study, we demonstrated that the over-expression of pectin methylesterase, derived from Arabidopsis thaliana and Aspergillus niger, in transgenic tobacco plants enhances methanol production and resistance to polyphagous insect pests. Methanol content in the leaves of transgenic plants was measured using proton nuclear spectroscopy (1H NMR and spectra showed up to 16 fold higher methanol as compared to control wild type (WT plants. A maximum of 100 and 85% mortality in chewing insects Helicoverpa armigera and Spodoptera litura larvae was observed, respectively when fed on transgenic plants leaves. The surviving larvae showed less feeding, severe growth retardation and could not develop into pupae. In-planta bioassay on transgenic lines showed up to 99 and 75% reduction in the population multiplication of plant sap sucking pests Myzus persicae (aphid and Bemisia tabaci (whitefly, respectively. Most of the phenotypic characters of transgenic plants were similar to WT plants. Confocal microscopy showed no deformities in cellular integrity, structure and density of stomata and trichomes of transgenic plants compared to WT. Pollen germination and tube formation was also not affected in transgenic plants. Cell wall enzyme transcript levels were comparable with WT. This study demonstrated for the first time that methanol emission can be utilized for imparting broad range insect resistance in plants.

  12. Enhanced methanol production in plants provides broad spectrum insect resistance.

    Science.gov (United States)

    Dixit, Sameer; Upadhyay, Santosh Kumar; Singh, Harpal; Sidhu, Om Prakash; Verma, Praveen Chandra; K, Chandrashekar

    2013-01-01

    Plants naturally emit methanol as volatile organic compound. Methanol is toxic to insect pests; but the quantity produced by most of the plants is not enough to protect them against invading insect pests. In the present study, we demonstrated that the over-expression of pectin methylesterase, derived from Arabidopsis thaliana and Aspergillus niger, in transgenic tobacco plants enhances methanol production and resistance to polyphagous insect pests. Methanol content in the leaves of transgenic plants was measured using proton nuclear spectroscopy (1H NMR) and spectra showed up to 16 fold higher methanol as compared to control wild type (WT) plants. A maximum of 100 and 85% mortality in chewing insects Helicoverpa armigera and Spodoptera litura larvae was observed, respectively when fed on transgenic plants leaves. The surviving larvae showed less feeding, severe growth retardation and could not develop into pupae. In-planta bioassay on transgenic lines showed up to 99 and 75% reduction in the population multiplication of plant sap sucking pests Myzus persicae (aphid) and Bemisia tabaci (whitefly), respectively. Most of the phenotypic characters of transgenic plants were similar to WT plants. Confocal microscopy showed no deformities in cellular integrity, structure and density of stomata and trichomes of transgenic plants compared to WT. Pollen germination and tube formation was also not affected in transgenic plants. Cell wall enzyme transcript levels were comparable with WT. This study demonstrated for the first time that methanol emission can be utilized for imparting broad range insect resistance in plants.

  13. Enhanced Methanol Production in Plants Provides Broad Spectrum Insect Resistance

    Science.gov (United States)

    Dixit, Sameer; Upadhyay, Santosh Kumar; Singh, Harpal; Sidhu, Om Prakash; Verma, Praveen Chandra; K, Chandrashekar

    2013-01-01

    Plants naturally emit methanol as volatile organic compound. Methanol is toxic to insect pests; but the quantity produced by most of the plants is not enough to protect them against invading insect pests. In the present study, we demonstrated that the over-expression of pectin methylesterase, derived from Arabidopsis thaliana and Aspergillus niger, in transgenic tobacco plants enhances methanol production and resistance to polyphagous insect pests. Methanol content in the leaves of transgenic plants was measured using proton nuclear spectroscopy (1H NMR) and spectra showed up to 16 fold higher methanol as compared to control wild type (WT) plants. A maximum of 100 and 85% mortality in chewing insects Helicoverpa armigera and Spodoptera litura larvae was observed, respectively when fed on transgenic plants leaves. The surviving larvae showed less feeding, severe growth retardation and could not develop into pupae. In-planta bioassay on transgenic lines showed up to 99 and 75% reduction in the population multiplication of plant sap sucking pests Myzus persicae (aphid) and Bemisia tabaci (whitefly), respectively. Most of the phenotypic characters of transgenic plants were similar to WT plants. Confocal microscopy showed no deformities in cellular integrity, structure and density of stomata and trichomes of transgenic plants compared to WT. Pollen germination and tube formation was also not affected in transgenic plants. Cell wall enzyme transcript levels were comparable with WT. This study demonstrated for the first time that methanol emission can be utilized for imparting broad range insect resistance in plants. PMID:24223989

  14. Diversity, Biocontrol, and Plant Growth Promoting Abilities of Xylem Residing Bacteria from Solanaceous Crops

    Directory of Open Access Journals (Sweden)

    Gauri A. Achari

    2014-01-01

    Full Text Available Eggplant (Solanum melongena L. is one of the solanaceous crops of economic and cultural importance and is widely cultivated in the state of Goa, India. Eggplant cultivation is severely affected by bacterial wilt caused by Ralstonia solanacearum that colonizes the xylem tissue. In this study, 167 bacteria were isolated from the xylem of healthy eggplant, chilli, and Solanum torvum Sw. by vacuum infiltration and maceration. Amplified rDNA restriction analysis (ARDRA grouped these xylem residing bacteria (XRB into 38 haplotypes. Twenty-eight strains inhibited growth of R. solanacearum and produced volatile and diffusible antagonistic compounds and plant growth promoting substances in vitro. Antagonistic strains XB86, XB169, XB177, and XB200 recorded a biocontrol efficacy greater than 85% against BW and exhibited 12%–22 % increase in shoot length in eggplant in the greenhouse screening. 16S rRNA based identification revealed the presence of 23 different bacterial genera. XRB with high biocontrol and plant growth promoting activities were identified as strains of Staphylococcus sp., Bacillus sp., Streptomyces sp., Enterobacter sp., and Agrobacterium sp. This study is the first report on identity of bacteria from the xylem of solanaceous crops having traits useful in cultivation of eggplant.

  15. Ecogeography and utility to plant breeding of the crop wild relatives of sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Kantar, Michael B; Sosa, Chrystian C; Khoury, Colin K; Castañeda-Álvarez, Nora P; Achicanoy, Harold A; Bernau, Vivian; Kane, Nolan C; Marek, Laura; Seiler, Gerald; Rieseberg, Loren H

    2015-01-01

    Crop wild relatives (CWR) are a rich source of genetic diversity for crop improvement. Combining ecogeographic and phylogenetic techniques can inform both conservation and breeding. Geographic occurrence, bioclimatic, and biophysical data were used to predict species distributions, range overlap and niche occupancy in 36 taxa closely related to sunflower (Helianthus annuus L.). Taxa lacking comprehensive ex situ conservation were identified. The predicted distributions for 36 Helianthus taxa identified substantial range overlap, range asymmetry and niche conservatism. Specific taxa (e.g., Helianthus deblis Nutt., Helianthus anomalus Blake, and Helianthus divaricatus L.) were identified as targets for traits of interest, particularly for abiotic stress tolerance, and adaptation to extreme soil properties. The combination of techniques demonstrates the potential for publicly available ecogeographic and phylogenetic data to facilitate the identification of possible sources of abiotic stress traits for plant breeding programs. Much of the primary genepool (wild H. annuus) occurs in extreme environments indicating that introgression of targeted traits may be relatively straightforward. Sister taxa in Helianthus have greater range overlap than more distantly related taxa within the genus. This adds to a growing body of literature suggesting that in plants (unlike some animal groups), geographic isolation may not be necessary for speciation.

  16. Ecogeography and utility to plant breeding of the crop wild relatives of sunflower (Helianthus annuus L.

    Directory of Open Access Journals (Sweden)

    Michael Benjamin Kantar

    2015-10-01

    Full Text Available Crop wild relatives (CWR are a rich source of genetic diversity for crop improvement. Combining ecogeographic and phylogenetic techniques can inform both conservation and breeding. Geographic occurrence, bioclimatic, and biophysical data were used to predict species distributions, range overlap and niche occupancy in 36 taxa closely related to sunflower (Helianthus annuus L.. Taxa lacking comprehensive ex situ conservation were identified. The predicted distributions for 36 Helianthus taxa identified substantial range overlap and asymmetry and niche conservatism. Specific taxa (e.g., Helianthus deblis Nutt., Helianthus anomalus Blake, and Helianthus divaricatus L. were identified as targets for traits of interest, particularly for abiotic stress tolerance and adaptation to extreme soil properties. The combination of techniques demonstrates the potential for publicly available ecogeographic and phylogenetic data to facilitate the identification of possible sources of abiotic stress traits for plant breeding programs. Much of the primary genepool (wild H. annuus occurs in extreme environments indicating that introgression of targeted traits may be relatively straightforward. Sister taxa in Helianthus have greater range overlap than more distantly related taxa within the genus. This adds to a growing body of literature suggesting that in plants (unlike some animal groups, geographic isolation may not be necessary for speciation.

  17. Ecogeography and utility to plant breeding of the crop wild relatives of sunflower (Helianthus annuus L.)

    Science.gov (United States)

    Kantar, Michael B.; Sosa, Chrystian C.; Khoury, Colin K.; Castañeda-Álvarez, Nora P.; Achicanoy, Harold A.; Bernau, Vivian; Kane, Nolan C.; Marek, Laura; Seiler, Gerald; Rieseberg, Loren H.

    2015-01-01

    Crop wild relatives (CWR) are a rich source of genetic diversity for crop improvement. Combining ecogeographic and phylogenetic techniques can inform both conservation and breeding. Geographic occurrence, bioclimatic, and biophysical data were used to predict species distributions, range overlap and niche occupancy in 36 taxa closely related to sunflower (Helianthus annuus L.). Taxa lacking comprehensive ex situ conservation were identified. The predicted distributions for 36 Helianthus taxa identified substantial range overlap, range asymmetry and niche conservatism. Specific taxa (e.g., Helianthus deblis Nutt., Helianthus anomalus Blake, and Helianthus divaricatus L.) were identified as targets for traits of interest, particularly for abiotic stress tolerance, and adaptation to extreme soil properties. The combination of techniques demonstrates the potential for publicly available ecogeographic and phylogenetic data to facilitate the identification of possible sources of abiotic stress traits for plant breeding programs. Much of the primary genepool (wild H. annuus) occurs in extreme environments indicating that introgression of targeted traits may be relatively straightforward. Sister taxa in Helianthus have greater range overlap than more distantly related taxa within the genus. This adds to a growing body of literature suggesting that in plants (unlike some animal groups), geographic isolation may not be necessary for speciation. PMID:26500675

  18. Metal resistant plants and phytoremediation of environmental contamination

    Science.gov (United States)

    Meagher, Richard B.; Li, Yujing; Dhankher, Om P.

    2010-04-20

    The present disclosure provides a method of producing transgenic plants which are resistant to at least one metal ion by transforming the plant with a recombinant DNA comprising a nucleic acid encoding a bacterial arsenic reductase under the control of a plant expressible promoter, and a nucleic acid encoding a nucleotide sequence encoding a phytochelatin biosynthetic enzyme under the control of a plant expressible promoter. The invention also relates a method of phytoremediation of a contaminated site by growing in the site a transgenic plant expressing a nucleic acid encoding a bacterial arsenate reductase and a nucleic acid encoding a phytochelatin biosynthetic enzyme.

  19. Simulating Crop Evapotranspiration Response under Different Planting Scenarios by Modified SWAT Model in an Irrigation District, Northwest China.

    Directory of Open Access Journals (Sweden)

    Xin Liu

    Full Text Available Modelling crop evapotranspiration (ET response to different planting scenarios in an irrigation district plays a significant role in optimizing crop planting patterns, resolving agricultural water scarcity and facilitating the sustainable use of water resources. In this study, the SWAT model was improved by transforming the evapotranspiration module. Then, the improved model was applied in Qingyuan Irrigation District of northwest China as a case study. Land use, soil, meteorology, irrigation scheduling and crop coefficient were considered as input data, and the irrigation district was divided into subdivisions based on the DEM and local canal systems. On the basis of model calibration and verification, the improved model showed better simulation efficiency than did the original model. Therefore, the improved model was used to simulate the crop evapotranspiration response under different planting scenarios in the irrigation district. Results indicated that crop evapotranspiration decreased by 2.94% and 6.01% under the scenarios of reducing the planting proportion of spring wheat (scenario 1 and summer maize (scenario 2 by keeping the total cultivated area unchanged. However, the total net output values presented an opposite trend under different scenarios. The values decreased by 3.28% under scenario 1, while it increased by 7.79% under scenario 2, compared with the current situation. This study presents a novel method to estimate crop evapotranspiration response under different planting scenarios using the SWAT model, and makes recommendations for strategic agricultural water management planning for the rational utilization of water resources and development of local economy by studying the impact of planting scenario changes on crop evapotranspiration and output values in the irrigation district of northwest China.

  20. Simulating Crop Evapotranspiration Response under Different Planting Scenarios by Modified SWAT Model in an Irrigation District, Northwest China.

    Science.gov (United States)

    Liu, Xin; Wang, Sufen; Xue, Han; Singh, Vijay P

    2015-01-01

    Modelling crop evapotranspiration (ET) response to different planting scenarios in an irrigation district plays a significant role in optimizing crop planting patterns, resolving agricultural water scarcity and facilitating the sustainable use of water resources. In this study, the SWAT model was improved by transforming the evapotranspiration module. Then, the improved model was applied in Qingyuan Irrigation District of northwest China as a case study. Land use, soil, meteorology, irrigation scheduling and crop coefficient were considered as input data, and the irrigation district was divided into subdivisions based on the DEM and local canal systems. On the basis of model calibration and verification, the improved model showed better simulation efficiency than did the original model. Therefore, the improved model was used to simulate the crop evapotranspiration response under different planting scenarios in the irrigation district. Results indicated that crop evapotranspiration decreased by 2.94% and 6.01% under the scenarios of reducing the planting proportion of spring wheat (scenario 1) and summer maize (scenario 2) by keeping the total cultivated area unchanged. However, the total net output values presented an opposite trend under different scenarios. The values decreased by 3.28% under scenario 1, while it increased by 7.79% under scenario 2, compared with the current situation. This study presents a novel method to estimate crop evapotranspiration response under different planting scenarios using the SWAT model, and makes recommendations for strategic agricultural water management planning for the rational utilization of water resources and development of local economy by studying the impact of planting scenario changes on crop evapotranspiration and output values in the irrigation district of northwest China.

  1. When a Plant Resistance Inducer Leaves the Lab for the Field: Integrating ASM into Routine Apple Protection Practices.

    Science.gov (United States)

    Marolleau, Brice; Gaucher, Matthieu; Heintz, Christelle; Degrave, Alexandre; Warneys, Romain; Orain, Gilles; Lemarquand, Arnaud; Brisset, Marie-Noëlle

    2017-01-01

    Plant resistance inducers, also called elicitors, could be useful to reduce the use of pesticides. However, their performance in controlling diseases in the field remains unsatisfactory due to lack of specific knowledge of how they can integrate crop protection practices. In this work, we focused on apple crop and acibenzolar- S -methyl (ASM), a well-known SAR (systemic acquired resistance) inducer of numerous plant species. We provide a protocol for orchard-effective control of apple scab due to the ascomycete fungus Venturia inaequalis , by applying ASM in combination with a light integrated pest management program. Besides we pave the way for future optimization levers by demonstrating in controlled conditions (i) the high influence of apple genotypes, (ii) the ability of ASM to prime defenses in newly formed leaves, (iii) the positive effect of repeated elicitor applications, (iv) the additive effect of a thinning fruit agent.

  2. Inducing Fungus-Resistance into Plants through Biotechnology

    Directory of Open Access Journals (Sweden)

    Shabir Hussain WANI

    2010-06-01

    Full Text Available Plant diseases are caused by a variety of plant pathogens including fungi, and their management requires the use of techniques like transgenic technology, molecular biology, and genetics. There have been attempts to use gene technology as an alternative method to protect plants from microbial diseases, in addition to the development of novel agrochemicals and the conventional breeding of resistant cultivars. Various genes have been introduced into plants, and the enhanced resistance against fungi has been demonstrated. These include: genes that express proteins, peptides, or antimicrobial compounds that are directly toxic to pathogens or that reduce their growth in situ; gene products that directly inhibit pathogen virulence products or enhance plant structural defense genes, that directly or indirectly activate general plant defense responses; and resistance genes involved in the hypersensitive response and in the interactions with virulence factors. The introduction of the tabtoxin acetyltransferase gene, the stilbene synthase gene, the ribosome-inactivation protein gene and the glucose oxidase gene brought enhanced resistance in different plants. Genes encoding hydrolytic enzymes such as chitinase and glucanase, which can deteriorate fungal cell-wall components, are attractive candidates for this approach and are preferentially used for the production of fungal disease-resistant plants. In addition to this, RNA-mediated gene silencing is being tried as a reverse tool for gene targeting in plant diseases caused by fungal pathogens. In this review, different mechanisms of fungal disease resistance through biotechnological approaches are discussed and the recent advances in fungal disease management through transgenic approach are reviewed.

  3. Linking the planting of cover crops to soil and water nutrient dynamics in Shatto Ditch Watershed, IN

    Science.gov (United States)

    Christopher, S. F.; Tank, J. L.; Hanrahan, B. R.; Mahl, U. H.; Huang, K.

    2013-12-01

    Tile drainage systems are common in the Midwest, and facilitate the transfer of excess inorganic nitrogen (N) and phosphorus (P) from agricultural soils to adjacent streams. These non-point sources contribute to elevated nutrient loads to tributaries in the Mississippi River Basin, which have been linked to widespread hypoxia and associated ecological and economic problems in the Gulf of Mexico. In agricultural areas dominated by row-crops, the planting of cover crops after the cash crop has been harvested offers a potential mechanism to reduce nutrient leaching from fields to tile drains in the off-season. In general, cover crops retain nutrients on fields and increase soil organic matter (SOM) content after they are harvested. The planting of cover crops also promotes immobilization of soil N and reduction in losses of dissolved P from soils due to reduced erosion, resulting in significantly less leaching to surface waters through tile drains. As part of a demonstration project in the Shatto Ditch Watershed, located in the Tippecanoe River Basin, IN, we are testing whether the planting of cover crops will influence soil nutrient and organic matter, and how cover crops alter the dynamics of nutrient leaching from tile drains. We have been sampling tile drain outflows on a twice-monthly sampling regime and have been measuring dissolved inorganic N and P concentrations in tile water since November 2012. During Spring 2013, tile drain nitrate concentrations sampled synoptically throughout the watershed ranged from 2.6 - 38.9 mg NO3- L -1 (mean = 17.2 +/- 1.6 mg NO3- L -1) with the lowest concentrations coming from fields planted in cover crops (range = 2.6 - 19.0 mg NO3- L -1, mean = 9.7 +/- 1.5 mg NO3- L -1). In contrast, soluble reactive phosphorus (SRP) concentrations were much lower in tile drain water and ranged from 7.5 - 182.7 μg L-1 (mean = 24.5 +/- 5.0 μg L-1 SRP) and preliminary data suggest that there were no differences between fields with and without

  4. High yielding tropical energy crops for bioenergy production: Effects of plant components, harvest years and locations on biomass composition.

    Science.gov (United States)

    Surendra, K C; Ogoshi, Richard; Zaleski, Halina M; Hashimoto, Andrew G; Khanal, Samir Kumar

    2018-03-01

    The composition of lignocellulosic feedstock, which depends on crop type, crop management, locations and plant parts, significantly affects the conversion efficiency of biomass into biofuels and biobased products. Thus, this study examined the composition of different parts of two high yielding tropical energy crops, Energycane and Napier grass, collected across three locations and years. Significantly higher fiber content was found in the leaves of Energycane than stems, while fiber content was significantly higher in the stems than the leaves of Napier grass. Similarly, fiber content was higher in Napier grass than Energycane. Due to significant differences in biomass composition between the plant parts within a crop type, neither biological conversion, including anaerobic digestion, nor thermochemical pretreatment alone is likely to efficiently convert biomass components into biofuels and biobased products. However, combination of anaerobic digestion with thermochemical conversion technologies could efficiently utilize biomass components in generating biofuels and biobased products. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Bacterial elicitors and plant signaling in induced systemic resistance

    OpenAIRE

    Bakker, P.A.H.M.; Pelt, J.A. van; Sluis, I. van der; Pieterse, C.M.J.

    2008-01-01

    Plant root colonizing, fluorescent Pseudomonas spp. have been studied for decades for their plant growth promoting properties and their effective suppression of soil borne plant diseases. The modes of action that play a role in disease suppression by these bacteria include siderophore-mediated competition for iron, antibiosis, and induced systemic resistance (ISR). The involvement of ISR is typically studied in systems in which the Pseudomonas bacteria and the pathogen are inoculated and rema...

  6. Non-host Plant Resistance against Phytophthora capsici Is Mediated in Part by Members of the I2 R Gene Family in Nicotiana spp.

    Science.gov (United States)

    Vega-Arreguín, Julio C; Shimada-Beltrán, Harumi; Sevillano-Serrano, Jacobo; Moffett, Peter

    2017-01-01

    The identification of host genes associated with resistance to Phytophthora capsici is crucial to developing strategies of control against this oomycete pathogen. Since there are few sources of resistance to P. capsici in crop plants, non-host plants represent a promising source of resistance genes as well as excellent models to study P. capsici - plant interactions. We have previously shown that non-host resistance to P. capsici in Nicotiana spp. is mediated by the recognition of a specific P. capsici effector protein, PcAvr3a1 in a manner that suggests the involvement of a cognate disease resistance (R) genes. Here, we have used virus-induced gene silencing (VIGS) and transgenic tobacco plants expressing dsRNA in Nicotiana spp. to identify candidate R genes that mediate non-host resistance to P. capsici . Silencing of members of the I2 multigene family in the partially resistant plant N. edwardsonii and in the resistant N. tabacum resulted in compromised resistance to P. capsici . VIGS of two other components required for R gene-mediated resistance, EDS1 and SGT1 , also enhanced susceptibility to P. capsici in N. edwardsonii , as well as in the susceptible plants N. benthamiana and N. clevelandii . The silencing of I2 family members in N. tabacum also compromised the recognition of PcAvr3a1. These results indicate that in this case, non-host resistance is mediated by the same components normally associated with race-specific resistance.

  7. Rapid cloning of disease-resistance genes in plants using mutagenesis and sequence capture

    Science.gov (United States)

    Genetic solutions to protect crops against pests and pathogens are preferable to agrichemicals 1. Wild crop relatives carry immense diversity of disease resistance (R) genes that could enable more sustainable disease control. However, recruiting R genes for crop improvement typically involves long b...

  8. Effect of crop development on biogenic emissions from plant populations grown in closed plant growth chambers

    Science.gov (United States)

    Batten, J. H.; Stutte, G. W.; Wheeler, R. M.

    1995-01-01

    The Biomass Production Chamber at John F. Kennedy Space Center is a closed plant growth chamber facility that can be used to monitor the level of biogenic emissions from large populations of plants throughout their entire growth cycle. The head space atmosphere of a 26-day-old lettuce (Lactuca sativa cv. Waldmann's Green) stand was repeatedly sampled and emissions identified and quantified using GC-mass spectrometry. Concentrations of dimethyl sulphide, carbon disulphide, alpha-pinene, furan and 2-methylfuran were not significantly different throughout the day; whereas, isoprene showed significant differences in concentration between samples collected in light and dark periods. Volatile organic compounds from the atmosphere of wheat (Triticum aestivum cv. Yecora Rojo) were analysed and quantified from planting to maturity. Volatile plant-derived compounds included 1-butanol, 2-ethyl-1-hexanol, nonanal, benzaldehyde, tetramethylurea, tetramethylthiourea, 2-methylfuran and 3-methylfuran. Concentrations of volatiles were determined during seedling establishment, vegetative growth, anthesis, grain fill and senescence and found to vary depending on the developmental stage. Atmospheric concentrations of benzaldehyde and nonanal were highest during anthesis, 2-methylfuran and 3-methylfuran concentrations were greatest during grain fill, and the concentration of the tetramethylurea peaked during senescence.

  9. Herbicide and cover crop residue integration for amaranthus control in conservation agriculture cotton and implications for resistance management

    Science.gov (United States)

    Conservation agriculture (CA) practices are threatened by glyphosate-resistant Palmer amaranth. Integrated control practices including PRE herbicides and high-residue CA systems can decrease Amaranthus emergence. Field experiments were conducted from autumn 2006 through crop harvest in 2009 at two s...

  10. Root isolations of Metarhizium spp. from crops reflect diversity in the soil and indicate no plant specificity

    DEFF Research Database (Denmark)

    Steinwender, Bernhardt M.; Enkerli, Jürg; Widmer, Franco

    2015-01-01

    revealed a comparable community composition as previously reported from the same agroecosystem when insect baiting of soil samples was used as isolating technique. No specific MLG association with a certain crop was found. This study highlights the diversity of Metarhizium spp. found in the rhizosphere...... of different crops within a single agroecosystem and suggests that plants either recruit fungal associates from the surrounding soil environment or even govern the composition of Metarhizium populations....

  11. Soil-to-Plant Transfer Factors of {sup 99}Tc for Korean Major Upland Crops

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yong Ho; Lim, Kwang Muk; Jun, In; Keum, Dong Kwon [Korea Atomic Energy Reserach Institute, Daejeon (Korea, Republic of)

    2011-12-15

    In order to investigate the soil-to-plant transfer factor (TF) of {sup 99}Tc for Korean major upland crops (soybean, radish and Chinese cabbage), pot experiments were performed in a greenhouse. Soils were collected from four upland fields (two for soybean and two for radish and Chinese cabbage) around Gyeongju radioactive-waste disposal site. Three to four weeks before sowing, dried soils were mixed with a {sup 99}Tc solution and the mixtures were put into pots and irrigated. TF values were expressed as the ratios of the {sup 99}Tc concentrations in plants (Bq kg{sup -1}-dry or fresh) to those in soils (Bq kg{sup -1}-dry). There was no great difference in the TF value between soils. The TF values for soybean seeds were extremely lower than those for the straws, indicating a very low mobility of {sup 99}Tc to seeds. As representative TF values of{sup 99}Tc,1.8 X 10{sup -1}, 1.2 X 10{sup 1}, 3.2 X 10{sup 2} and 1.3 X 10{sup 2} (for dry plants), arithmetic means for two soils, were proposed for soybean seeds, radish roots, radish leaves and Chinese cabbage leaves, respectively. In the case of the vegetables, proposals for fresh plants were also made. The proposed values are not sufficiently representative so successive updates are needed.

  12. Plants + microbes: Innovative food crop systems that also clean air and water

    Science.gov (United States)

    Nelson, Mark; Wolverton, B. C.

    The limitations that will govern bioregenerative life support applications in space, especially volume and weight, make multi-purpose systems advantageous. This paper outlines two systems which utilize plants and associated microbial communities of root or growth medium to both produce food crops and clean air and water. Underlying these approaches are the large numbers and metabolic diversity of microbes associated with roots and found in either soil or other suitable growth media. It is known that most biogeochemical cycles have a microbial link, and the ability of microbes to metabolize virtually all trace gases, whether of technogenic or biogenic origin, have long been established. Wetland plants and soil/media also been extensively researched for their ability to purify wastewaters of all kinds of potential water pollutants, from nutrients like N and P, to heavy metals and a range of complex industrial pollutants. There is a growing body of research on the ability of higher plants to purify air and water. Associated benefits of these approaches is that by utilizing natural ecological processes, the cleansing of air and water can be done with little or no energy inputs. Soil and root microorganisms respond to changing pollutant types by an increase of the types of organisms with the capacity to use these compounds. Thus living systems have an extraordinary adaptive capacity as long as the starting populations are sufficiently diverse. It is known that tightly sealed environments, from office buildings to spacecraft, can have hundreds or even thousands of potential air pollutants, depending on the materials and machines enclosed. Human waste products carry a plethora of microbes can are readily used in the process of converting its organic load to forms that can be utilized by green plants. Having endogenous means of responding to changing air and water quality conditions represents safety factors which operate without the need for human direction. We will

  13. Plants + soil/wetland microbes: Food crop systems that also clean air and water

    Science.gov (United States)

    Nelson, Mark; Wolverton, B. C.

    2011-02-01

    The limitations that will govern bioregenerative life support applications in space, especially volume and weight, make multi-purpose systems advantageous. This paper outlines two systems which utilize plants and associated microbial communities of root or growth medium to both produce food crops and clean air and water. Underlying these approaches are the large numbers and metabolic diversity of microbes associated with roots and found in either soil or other suitable growth media. Biogeochemical cycles have microbial links and the ability of microbes to metabolize virtually all trace gases, whether of technogenic or biogenic origin, has long been established. Wetland plants and the rootzone microbes of wetland soils/media also been extensively researched for their ability to purify wastewaters of a great number of potential water pollutants, from nutrients like N and P, to heavy metals and a range of complex industrial pollutants. There is a growing body of research on the ability of higher plants to purify air and water. Associated benefits of these approaches is that by utilizing natural ecological processes, the cleansing of air and water can be done with little or no energy inputs. Soil and rootzone microorganisms respond to changing pollutant types by an increase of the types of organisms with the capacity to use these compounds. Thus living systems have an adaptive capacity as long as the starting populations are sufficiently diverse. Tightly sealed environments, from office buildings to spacecraft, can have hundreds or even thousands of potential air pollutants, depending on the materials and equipment enclosed. Human waste products carry a plethora of microbes which are readily used in the process of converting its organic load to forms that can be utilized by green plants. Having endogenous means of responding to changing air and water quality conditions represents safety factors as these systems operate without the need for human intervention. We review

  14. Micrografting for fruit crop improvement | Hussain | African Journal of ...

    African Journals Online (AJOL)

    ... histological studies, disease indexing, production of disease-free plants particularly resistant to soil borne pathogens and multiplication of difficult to root plants. Keywords: Fruit crops, graft incompatibility, crop improvement, micrografting, propagation, shoot tip grafting. African Journal of Biotechnology, Vol 13(25) 2474- ...

  15. Effect of planting density on root lodging resistance and its relationship to nodal root growth characteristics in maize (Zea mays L.)

    DEFF Research Database (Denmark)

    Liu, Shengqun; Song, Fengbin; Liu, Fulai

    2012-01-01

    , an indicator of root lodging resistance, was significantly affected by the planting density, the maize variety, as well as the crop developmental stages, and was decreased with increasing planting density. The number and the average diameter of the roots on the upper internodes (phytomer 5 to 8) were decreased...... correlated with the total root number and the average root diameter on the upper internodes, indicating that a greater root number and a larger root diameter are important traits for enhancing root lodging resistance in maize plants.......Increase of planting density has been widely used to increase grain yield in maize. However, it may lead to higher risk of root lodging hence causing significant yield loss of the crop. The objective of this study was to investigate the effect of planting density on maize nodal root growth...

  16. SCREENING FOR DEVELOPMENT OF HOST PLANT RESISTANCE ...

    African Journals Online (AJOL)

    Tangaza

    losses of cowpea yields and if not controlled, they limit the yields to less than 300kg/ha (Singh et al., 1990). A considerable progress has been made during the past decade in cowpea breeding and a range of varieties have been developed with resistance to several diseases, insect pests and parasitic weeds. Much time ...

  17. Suppression among alleles encoding nucleotide-binding-leucine-rich repeat resistance proteins interferes with resistance in F1 hybrid and allele-pyramided wheat plants.

    Science.gov (United States)

    Stirnweis, Daniel; Milani, Samira D; Brunner, Susanne; Herren, Gerhard; Buchmann, Gabriele; Peditto, David; Jordan, Tina; Keller, Beat

    2014-09-01

    The development of high-yielding varieties with broad-spectrum durable disease resistance is the ultimate goal of crop breeding. In plants, immune receptors of the nucleotide-binding-leucine-rich repeat (NB-LRR) class mediate race-specific resistance against pathogen attack. When employed in agriculture this type of resistance is often rapidly overcome by newly adapted pathogen races. The stacking of different resistance genes or alleles in F1 hybrids or in pyramided lines is a promising strategy for achieving more durable resistance. Here, we identify a molecular mechanism which can negatively interfere with the allele-pyramiding approach. We show that pairwise combinations of different alleles of the powdery mildew resistance gene Pm3 in F1 hybrids and stacked transgenic wheat lines can result in suppression of Pm3-based resistance. This effect is independent of the genetic background and solely dependent on the Pm3 alleles. Suppression occurs at the post-translational level, as levels of RNA and protein in the suppressed alleles are unaffected. Using a transient expression system in Nicotiana benthamiana, the LRR domain was identified as the domain conferring suppression. The results of this study suggest that the expression of closely related NB-LRR resistance genes or alleles in the same genotype can lead to dominant-negative interactions. These findings provide a molecular explanation for the frequently observed ineffectiveness of resistance genes introduced from the secondary gene pool into polyploid crop species and mark an important step in overcoming this limitation. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

  18. Introgression of physiological traits for a comprehensive improvement of drought adaptation in crop plants

    Science.gov (United States)

    Sreeman, Sheshshayee M.; Vijayaraghavareddy, Preethi; Sreevathsa, Rohini; Rajendrareddy, Sowmya; Arakesh, Smitharani; Bharti, Pooja; Dharmappa, Prathibha; Soolanayakanahally, Raju

    2018-04-01

    Burgeoning population growth, industrial demand and the predicted global climate change resulting in erratic monsoon rains are expected to severely limit fresh water availability for agriculture both in irrigated and rainfed ecosystems. In order to remain food and nutrient secure, agriculture research needs to focus on devising strategies to save water in irrigated conditions and to develop superior cultivars with improved water productivity to sustain yield under rainfed conditions. Recent opinions accruing in the scientific literature strongly favour the adoption of a “trait based” approach for increasing water productivity especially the traits associated with maintenance of positive tissue turgor and maintenance of increased carbon assimilation as the most relevant traits to improve crop growth rates under water limiting conditions and to enhance water productivity. The advent of several water saving agronomic practices notwithstanding, a genetic enhancement strategy of introgressing distinct physiological, morphological and cellular mechanisms on to a single elite genetic background is essential for achieving a comprehensive improvement in drought adaptation in crop plants. The significant progress made in genomics, though would provide the necessary impetus, a clear understanding of the “traits” to be introgressed is the most essential need of the hour. Water uptake by a better root architecture, water conservation by preventing unproductive transpiration is crucial for maintaining positive tissue water relations. Improved carbon assimilation associated with carboxylation capacity and mesophyll conductance is equally important in sustaining crop growth rates under water limited conditions. Besides these major traits, we summarized the available information in literature on classifying various drought adaptive traits. We provide evidences that water-use efficiency when introgressed with moderately higher transpiration, would significantly enhance

  19. Advances in managing pest resistance to Bt crops: Pyramids and seed mixtures

    Science.gov (United States)

    Transgenic crops producing toxins from the soil bacterium Bacillus thuringiensis (Bt) have been widely used for the control of insect pests during the last 20 years. Although Bt crops have provided significant environmental and economic benefits, sustainable use of these crops is threatened by the r...

  20. Biotech/GM crops in horticulture: plum cv. HoneySweet resistant to plum pox virus

    Science.gov (United States)

    Commercialization of Biotech crops started in 1995. By 2011, genetically modified (GM) crops were grown world-wide on 160 million ha. Only 114.507 ha of GM crops were grown in Europe, of that, 114.490 ha were Bt maize and 17 ha were potato for industrial starch production. Currently, developing c...

  1. Promotion of growth and Cu accumulation of bio-energy crop (Zea mays) by bacteria: implications for energy plant biomass production and phytoremediation.

    Science.gov (United States)

    Sheng, Xiafang; Sun, Leni; Huang, Zhi; He, Linyan; Zhang, Wenhui; Chen, Zhaojin

    2012-07-30

    Three metal-resistant and plant growth-promoting bacteria (Burkholderia sp. GL12, Bacillus megaterium JL35 and Sphingomonas sp. YM22) were evaluated for their potential to solubilize Cu(2) (OH)(2)CO(3) in solution culture and their plant growth promotion and Cu uptake in maize (Zea mays, an energy crop) grown in a natural highly Cu-contaminated soil. The impacts of the bacteria on the Cu availability and the bacterial community in rhizosphere soils of maize were also investigated. Inductively coupled-plasma optical emission spectrometer analysis showed variable amounts of water-soluble Cu (ranging from 20.5 to 227 mgL(-1)) released by the bacteria from Cu(2) (OH)(2)CO(3) in solution culture. Inoculation with the bacteria was found to significantly increase root (ranging from 48% to 83%) and above-ground tissue (ranging from 33% to 56%) dry weights of maize compared to the uninoculated controls. Increases in Cu contents of roots and above-ground tissues varied from 69% to 107% and from 16% to 86% in the bacterial-inoculated plants compared to the uninoculated controls, respectively. Inoculation with the bacteria was also found to significantly increase the water-extractive Cu concentrations (ranging from 63 to 94%) in the rhizosphere soils of the maize plants compared to the uninoculated controls in pot experiments. Denaturing gradient gel electrophoresis and sequence analyses showed that the bacteria could colonize the rhizosphere soils and significantly change the bacterial community compositions in the rhizosphere soils. These results suggest that the metal-resistant and plant growth-promoting bacteria may be exploited for promoting the maize (energy crop) biomass production and Cu phytoremediation in a natural highly Cu-contaminated soil. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Genetics of insect resistance to plant defence

    NARCIS (Netherlands)

    Vermeer, K.M.C.A.

    2014-01-01

    Plants are chemically defended against insect herbivory in various ways. They produce a broad range of secondary metabolites that may be toxic or deterrent to insects. Specialist insects, however, are often capable of overcoming these defences. The yellow striped flea beetle

  3. Plant probiotic bacteria enhance the quality of fruit and horticultural crops

    Directory of Open Access Journals (Sweden)

    Alejandro Jiménez-Gómez

    2017-06-01

    Full Text Available The negative effects on the environment and human health caused by the current farming systems based on the overuse of chemical fertilizers have been reported in many studies. By contrast, bacterial inoculations produce positive effects on yields without causing this type of harm. Hence, during recent years, the commercialization of biofertilizers has been on the increase, and the number of companies and products available are expanding worldwide every year. In addition to the notable enhancement of crop production, many studies have shown how the application of bacteria has positive effects on food quality such as improved vitamin, flavonoid and antioxidant content, among other benefits. This advantage is interesting with respect to food that is consumed raw, such as fruits and many vegetables, as these bioactive molecules are maintained up until the moment the food is consumed. As regards this review focuses on the collection of studies that demonstrate that microorganisms can act as plant probiotics of fruit and horticultural crops, essential types of food that form part of a healthy diet.

  4. Direct derivation of maize plant and crop height from low-cost time-of-flight camera measurements.

    Science.gov (United States)

    Hämmerle, Martin; Höfle, Bernhard

    2016-01-01

    In agriculture, information about the spatial distribution of crop height is valuable for applications such as biomass and yield estimation, or increasing field work efficiency in terms of fertilizing, applying pesticides, irrigation, etc. Established methods for capturing crop height often comprise restrictions in terms of cost and time efficiency, flexibility, and temporal and spatial resolution of measurements. Furthermore, crop height is mostly derived from a measurement of the bare terrain prior to plant growth and measurements of the crop surface when plants are growing, resulting in the need of multiple field campaigns. In our study, we examine a method to derive crop heights directly from data of a plot of full grown maize plants captured in a single field campaign. We assess continuous raster crop height models (CHMs) and individual plant heights derived from data collected with the low-cost 3D camera Microsoft ® Kinect ® for Xbox One™ based on a comprehensive comparison to terrestrial laser scanning (TLS) reference data. We examine single measurements captured with the 3D camera and a combination of the single measurements, i.e. a combination of multiple perspectives. The quality of both CHMs, and individual plant heights is improved by combining the measurements. R 2 of CHMs derived from single measurements range from 0.48 to 0.88, combining all measurements leads to an R 2 of 0.89. In case of individual plant heights, an R 2 of 0.98 is achieved for the combined measures (with R 2  = 0.44 for the single measurements). The crop heights derived from the 3D camera measurements comprise an average underestimation of 0.06 m compared to TLS reference values. We recommend the combination of multiple low-cost 3D camera measurements, removal of measurement artefacts, and the inclusion of correction functions to improve the quality of crop height measurements. Operating low-cost 3D cameras under field conditions on agricultural machines or on autonomous

  5. Mite Pests in Plant Crops – Current Issues, Inovative Approaches and Possibilities for Controlling Them (1

    Directory of Open Access Journals (Sweden)

    Radmila Petanović

    2010-01-01

    Full Text Available In the middle of the last century, mites moved into the focus of attention as pests relevantto agriculture, forestry and landscape horticulture, presumably in direct reactionto the “green revolution” that involved plant cultivation in large-plot monocropping systems,improved methods of cultivation, selection of high-yielding cultivars and intensifieduse of pesticides and mineral fertilizers. Agroecosystems in which phytophagous miteshave become harmful organisms are primarily orchards, vineyards, greenhouses, urbangreeneries, plant nurseries and stored plant products, as well as annual field crops to asomewhat lesser degree. Phytophagous mite species belong to a variety of spider mites(Tetranychidae, false spider mites (Tenuipalpidae, gall and rust mites (Eriophyoidae, tarsonemidmites (Tarsonemidae and acarid mites (Acaridae. Most of these harmful speciesare widespread, some of them having more economic impact than others and being moredetrimental as depending on various specificities of each outdoor agroecosystem in anyparticular climatic region.The first segment of this overview focuses on the most significant mite pests ofagroecosystemsand urban horticultural areas in European countries, our own region andin Serbia today, primarily on species that have caused problems in recent years regardingplant production, and it also discusses various molecular methods available for investigatingdifferent aspects of the biology of phytophagous mites. Also, acaricides are discussedas a method of controlling mite pests in the light of the current situation and trends on pesticidemarkets in Serbia and the European Union member-countries

  6. Innovative combination of spectroscopic techniques to reveal nanoparticle fate in a crop plant

    Science.gov (United States)

    Larue, Camille; Castillo-Michel, Hiram; Stein, Ricardo J.; Fayard, Barbara; Pouyet, Emeline; Villanova, Julie; Magnin, Valérie; Pradas del Real, Ana-Elena; Trcera, Nicolas; Legros, Samuel; Sorieul, Stéphanie; Sarret, Géraldine

    2016-05-01

    Nanotechnology is the new industrial revolution of our century. Its development leads to an increasing use of nanoparticles and thus to their dissemination. Their fate in the environment is of great concern and especially their possible transfer in trophic chains might be an issue for food safety. However, so far our knowledge on this topic has been restricted by the lack of appropriate techniques to characterize their behavior in complex matrices. Here, we present in detail the use of cutting-edge beam-based techniques for nanoparticle in situ localization, quantification and speciation in a crop plant species (Lactuca sativa). Lettuce seedlings have been exposed to TiO2 and Ag nanoparticles and analyzed by inductively coupled plasma spectrometry, micro-particle induced X-ray emission coupled to Rutherford backscattering spectroscopy on nuclear microprobe, micro-X-ray fluorescence spectroscopy and X-ray absorption near edge structure spectroscopy. The benefits and drawbacks of each technique are discussed, and the types of information that can be drawn, for example on the translocation to edible parts, change of speciation within the plant, detoxification mechanisms, or impact on the plant ionome, are highlighted. Such type of coupled approach would be an asset for nanoparticle risk assessment.

  7. Location of Bioelectricity Plants in the Madrid Community Based on Triticale Crop: A Multicriteria Methodology

    Directory of Open Access Journals (Sweden)

    L. Romero

    2015-01-01

    Full Text Available This paper presents a work whose objective is, first, to quantify the potential of the triticale biomass existing in each of the agricultural regions in the Madrid Community through a crop simulation model based on regression techniques and multiple correlation. Second, a methodology for defining which area has the best conditions for the installation of electricity plants from biomass has been described and applied. The study used a methodology based on compromise programming in a discrete multicriteria decision method (MDM context. To make a ranking, the following criteria were taken into account: biomass potential, electric power infrastructure, road networks, protected spaces, and urban nuclei surfaces. The results indicate that, in the case of the Madrid Community, the Campiña region is the most suitable for setting up plants powered by biomass. A minimum of 17,339.9 tons of triticale will be needed to satisfy the requirements of a 2.2 MW power plant. The minimum range of action for obtaining the biomass necessary in Campiña region would be 6.6 km around the municipality of Algete, based on Geographic Information Systems. The total biomass which could be made available in considering this range in this region would be 18,430.68 t.

  8. Evolving technologies for growing, imaging and analyzing 3D root system architecture of crop plants.

    Science.gov (United States)

    Piñeros, Miguel A; Larson, Brandon G; Shaff, Jon E; Schneider, David J; Falcão, Alexandre Xavier; Yuan, Lixing; Clark, Randy T; Craft, Eric J; Davis, Tyler W; Pradier, Pierre-Luc; Shaw, Nathanael M; Assaranurak, Ithipong; McCouch, Susan R; Sturrock, Craig; Bennett, Malcolm; Kochian, Leon V

    2016-03-01

    A plant's ability to maintain or improve its yield under limiting conditions, such as nutrient deficiency or drought, can be strongly influenced by root system architecture (RSA), the three-dimensional distribution of the different root types in the soil. The ability to image, track and quantify these root system attributes in a dynamic fashion is a useful tool in assessing desirable genetic and physiological root traits. Recent advances in imaging technology and phenotyping software have resulted in substantive progress in describing and quantifying RSA. We have designed a hydroponic growth system which retains the three-dimensional RSA of the plant root system, while allowing for aeration, solution replenishment and the imposition of nutrient treatments, as well as high-quality imaging of the root system. The simplicity and flexibility of the system allows for modifications tailored to the RSA of different crop species and improved throughput. This paper details the recent improvements and innovations in our root growth and imaging system which allows for greater image sensitivity (detection of fine roots and other root details), higher efficiency, and a broad array of growing conditions for plants that more closely mimic those found under field conditions. © 2015 Institute of Botany, Chinese Academy of Sciences.

  9. Using The Corngrass1 Gene To Enhance The Biofuel Properties Of Crop Plants

    Energy Technology Data Exchange (ETDEWEB)

    Hake, Sarah [USDA Agricultural Research Service, Washington DC (United States); Chuck, George [USDA Agricultural Research Service, Washington DC (United States)

    2015-10-29

    The development of novel plant germplasm is vital to addressing our increasing bioenergy demands. The major hurdle to digesting plant biomass is the complex structure of the cell walls, the substrate of fermentation. Plant cell walls are inaccessible matrices of macromolecules that are polymerized with lignin, making fermentation difficult. Overcoming this hurdle is a major goal toward developing usable bioenergy crop plants. Our project seeks to enhance the biofuel properties of perennial grass species using the Corngrass1 (Cg1) gene and its targets. Dominant maize Cg1 mutants produce increased biomass by continuously initiating extra axillary meristems and leaves. We cloned Cg1 and showed that its phenotype is caused by over expression of a unique miR156 microRNA gene that negatively regulates SPL transcription factors. We transferred the Cg1 phenotype to other plants by expressing the gene behind constitutive promoters in four different species, including the monocots, Brachypodium and switchgrass, and dicots, Arabidopsis and poplar. All transformants displayed a similar range of phenotypes, including increased biomass from extended leaf production, and increased vegetative branching. Field grown switchgrass transformants showed that overall lignin content was reduced, the ratio of glucans to xylans was increased, and surprisingly, that starch levels were greatly increased. The goals of this project are to control the tissue and temporal expression of Cg1 by using different promoters to drive its expression, elucidate the function of the SPL targets of Cg1 by generating gain and loss of function alleles, and isolate downstream targets of select SPL genes using deep sequencing and chromatin immunoprecipitation. We believe it is possible to control biomass accumulation, cell wall properties, and sugar levels through manipulation of either the Cg1 gene and/or its SPL targets.

  10. [Biodiversity of phosphate-dissolving and plant growth--promoting endophytic bacteria of two crops].

    Science.gov (United States)

    Huang, Jing; Sheng, Xiafang; He, Linyan

    2010-06-01

    We isolated and characterized phosphate-dissolving endophytic bacteria from two commonly cultivated crops. Phosphate-dissolving endophytic bacteria were isolated by plating and screening from interior tissues of rape and maize plants on NBRIP medium with tricalcium phosphate as sole phosphate source. Bacteria were characterized regarding characteristics that may be relevant for a beneficial plant-microbe interaction-indoleacetic acid, siderophore and 1-aminocyclopropane-1-carboxylic acid deaminase production,and further classified by restriction analysis of 16S rDNA. Eleven typical strains were identified by 16S rDNA sequence analysis. Thirty-two phosphate-dissolving endophytic bacteria were isolated from maize and rape plants and classified by restriction analysis of 16S rDNA in 8 different taxonomic groups at the similarity level of 76%. All the isolates could release phosphate from tricalcium phosphate and decrease the pH of the medium. The maximum phosphate content (537.6 mg/L) in the solution was obtained with strain M1L5. Thirteen isolates isolated from rape produced indoleacetic acid and siderophore, 68.4% and 63.2% of the strains isolated from maize produced indoleacetic acid and siderophore,respectively. 63.2% of the strains isolated from maize were able to grow on 1-aminocyclopropane-1-carboxylic acid as the sole nitrogen source. The eleven strains belonged to five different genera including Pantoea, Pseudomonas, Burkholderia, Acinetobacter and Ralstonia. Phosphate-dissolving endophytic bacteria isolated from rape and maize plants have abundant characteristics relative to promoting plant growth and genetic diversity.

  11. Using remote sensing to calculate plant available nitrogen needed by crops on swine factory farm sprayfields in North Carolina

    Science.gov (United States)

    Christenson, Elizabeth; Serre, Marc

    2015-10-01

    North Carolina (NC) is the second largest producer of hogs in the United States with Duplin county, NC having the densest population of hogs in the world. In NC, liquid swine manure is generally stored in open-air lagoons and sprayed onto sprayfields with sprinkler systems to be used as fertilizer for crops. Swine factory farms, termed concentrated animal feeding operations (CAFOs), are regulated by the Department of Environment and Natural Resources (DENR) based on nutrient management plans (NMPs) having balanced plant available nitrogen (PAN). The estimated PAN in liquid manure being sprayed must be less than the estimated PAN needed crops during irrigation. Estimates for PAN needed by crops are dependent on crop and soil types. Objectives of this research were to develop a new, time-efficient method to identify PAN needed by crops on Duplin county sprayfields for years 2010-2014. Using remote sensing data instead of NMP data to identify PAN needed by crops allowed calendar year identification of which crops were grown on sprayfields instead of a five-year range of values. Although permitted data have more detailed crop information than remotely sensed data, identification of PAN needed by crops using remotely sensed data is more time efficient, internally consistent, easily publically accessible, and has the ability to identify annual changes in PAN on sprayfields. Once PAN needed by crops is known, remote sensing can be used to quantify PAN at other spatial scales, such as sub-watershed levels, and can be used to inform targeted water quality monitoring of swine CAFOs.

  12. Tomato plant inheritance of antixenotic resistance to tomato leafminer

    Directory of Open Access Journals (Sweden)

    Adilson de Castro Antônio

    2011-01-01

    Full Text Available The objective of this work was to determine the inheritance of resistance by antixenosis in tomato plants (Lycopersicon esculentum to tomato leafminer [Tuta absoluta (Lepidoptera: Gelechiidae]. Evaluations were performed for tomato plants of the generations P1, P2, F1, F2, RC1 and RC2. The measured characteristic in the parents, BGH-1497 (P2 male and 'Santa Clara' (P1 female, and in the F1, F2, RC1 and RC2 generations was the number of eggs per plant. This number was converted to the oviposition nonpreference index. The inheritance of antixenosis resistance of genotype BGH-1497 is ruled by a gene of greater effect and polygenes in epistatic interactions, with a phenotypic proportion of 13:3 between susceptible and resistant genotypes, respectively.

  13. Radiation preservation of foods of plant origin. Part 1. Potatoes and other tuber crops

    International Nuclear Information System (INIS)

    Thomas, P.

    1984-01-01

    In Part 1 of a planned series of articles on preservation of foods of plant origin by gamma irradiation, the current state of research on the technological, nutritional, and biochemical aspects of sprout inhibition of potatoes and other tuber crops are reviewed. These include varietal responses, dose effects, time of irradiation, pre- and postirradiation storage, and handling requirements; postirradiation changes in carbohydrates, ascorbic acid, amino acids, and other nutrients; respiration; biochemical mechanisms involved in sprout inhibition; wound healing and microbial infection during storage; formation of wound and light-induced glycoalkaloids and identification of irradiated potatoes. The culinary and processing qualities with particular reference to darkening of boiled and processed potatoes are discussed. The prospects of irradiation on an industrial scale as an alternative to chemical sprout inhibitors or mechanical refrigeration are considered

  14. Food Allergy - Basic Mechanisms and Applications to Identifying Risks Associated with Plant Incorporated Pesticides and Other Genetically Modified Crops

    Science.gov (United States)

    Food allergy is a relatively new concern for toxicologists as a result of the incorporation of novel proteins into food crops in order to promote resistance to pests and other stresses, improve nutrition, or otherwise modify the phenotype. Food allergy can manifest as inflammatio...

  15. High throughput phenotyping for aphid resistance in large plant collections

    Directory of Open Access Journals (Sweden)

    Chen Xi

    2012-08-01

    Full Text Available Abstract Background Phloem-feeding insects are among the most devastating pests worldwide. They not only cause damage by feeding from the phloem, thereby depleting the plant from photo-assimilates, but also by vectoring viruses. Until now, the main way to prevent such problems is the frequent use of insecticides. Applying resistant varieties would be a more environmental friendly and sustainable solution. For this, resistant sources need to be identified first. Up to now there were no methods suitable for high throughput phenotyping of plant germplasm to identify sources of resistance towards phloem-feeding insects. Results In this paper we present a high throughput screening system to identify plants with an increased resistance against aphids. Its versatility is demonstrated using an Arabidopsis thaliana activation tag mutant line collection. This system consists of the green peach aphid Myzus persicae (Sulzer and the circulative virus Turnip yellows virus (TuYV. In an initial screening, with one plant representing one mutant line, 13 virus-free mutant lines were identified by ELISA. Using seeds produced from these lines, the putative candidates were re-evaluated and characterized, resulting in nine lines with increased resistance towards the aphid. Conclusions This M. persicae-TuYV screening system is an efficient, reliable and quick procedure to identify among thousands of mutated lines those resistant to aphids. In our study, nine mutant lines with increased resistance against the aphid were selected among 5160 mutant lines in just 5 months by one person. The system can be extended to other phloem-feeding insects and circulative viruses to identify insect resistant sources from several collections, including for example genebanks and artificially prepared mutant collections.

  16. Transgenic Brassica juncea plants expressing MsrA1, a synthetic cationic antimicrobial peptide, exhibit resistance to fungal phytopathogens.

    Science.gov (United States)

    Rustagi, Anjana; Kumar, Deepak; Shekhar, Shashi; Yusuf, Mohd Aslam; Misra, Santosh; Sarin, Neera Bhalla

    2014-06-01

    Cationic antimicrobial peptides (CAPs) have shown potential against broad spectrum of phytopathogens. Synthetic versions with desirable properties have been modeled on these natural peptides. MsrA1 is a synthetic chimera of cecropin A and melittin CAPs with antimicrobial properties. We generated transgenic Brassica juncea plants expressing the msrA1 gene aimed at conferring fungal resistance. Five independent transgenic lines were evaluated for resistance to Alternaria brassicae and Sclerotinia sclerotiorum, two of the most devastating pathogens of B. juncea crops. In vitro assays showed inhibition by MsrA1 of Alternaria hyphae growth by 44-62 %. As assessed by the number and size of lesions and time taken for complete leaf necrosis, the Alternaria infection was delayed and restricted in the transgenic plants with the protection varying from 69 to 85 % in different transgenic lines. In case of S. sclerotiorum infection, the lesions were more severe and spread profusely in untransformed control compared with transgenic plants. The sclerotia formed in the stem of untransformed control plants were significantly more in number and larger in size than those present in the transgenic plants where disease protection of 56-71.5 % was obtained. We discuss the potential of engineering broad spectrum biotic stress tolerance by transgenic expression of CAPs in crop plants.

  17. Community Profiling of Fusarium in Combination with Other Plant-Associated Fungi in Different Crop Species Using SMRT Sequencing

    Directory of Open Access Journals (Sweden)

    Florian Walder

    2017-11-01

    Full Text Available Fusarium head blight, caused by fungi from the genus Fusarium, is one of the most harmful cereal diseases, resulting not only in severe yield losses but also in mycotoxin contaminated and health-threatening grains. Fusarium head blight is caused by a diverse set of species that have different host ranges, mycotoxin profiles and responses to agricultural practices. Thus, understanding the composition of Fusarium communities in the field is crucial for estimating their impact and also for the development of effective control measures. Up to now, most molecular tools that monitor Fusarium communities on plants are limited to certain species and do not distinguish other plant associated fungi. To close these gaps, we developed a sequencing-based community profiling methodology for crop-associated fungi with a focus on the genus Fusarium. By analyzing a 1600 bp long amplicon spanning the highly variable segments ITS and D1–D3 of the ribosomal operon by PacBio SMRT sequencing, we were able to robustly quantify Fusarium down to species level through clustering against reference sequences. The newly developed methodology was successfully validated in mock communities and provided similar results as the culture-based assessment of Fusarium communities by seed health tests in grain samples from different crop species. Finally, we exemplified the newly developed methodology in a field experiment with a wheat-maize crop sequence under different cover crop and tillage regimes. We analyzed wheat straw residues, cover crop shoots and maize grains and we could reveal that the cover crop hairy vetch (Vicia villosa acts as a potent alternative host for Fusarium (OTU F.ave/tri showing an eightfold higher relative abundance compared with other cover crop treatments. Moreover, as the newly developed methodology also allows to trace other crop-associated fungi, we found that vetch and green fallow hosted further fungal plant pathogens including Zymoseptoria tritici

  18. Evaluation of developmental responses of two crop plants exposed to silver and zinc oxide nanoparticles.

    Science.gov (United States)

    Pokhrel, Lok R; Dubey, Brajesh

    2013-05-01

    The increasing applications of different nanomaterials in the myriad of nano-enabled products and their potential for leaching have raised considerable environmental, health and safety (EHS) concerns. As systematic studies investigating potential anomalies in the morphology and anatomy of crop plants are scarce, herein we report on the developmental responses of two agriculturally significant crop plants, maize (Zea mays L.) and cabbage (Brassica oleracea var. capitata L.), upon in vitro exposure to nanoparticles of citrate-coated silver (Citrate-nAg) and zinc oxide (nZnO). Analyses involve histology of the primary root morphology and anatomy using light microscopy, metal biouptake, moisture content, rate of germination, and root elongation. Comparative toxicity profiles of the ionic salts (AgNO3 and ZnSO4) are developed. Notably, we uncover structural changes in maize primary root cells upon exposure to Citrate-nAg, nZnO, AgNO3, and ZnSO4, possibly due to metal biouptake, suggesting potential for functional impairments in the plant growth and development. Citrate-nAg exposure results in lower Ag biouptake compared to AgNO3 treatment in maize. Microscopic evidence reveals 'tunneling-like effect' with nZnO treatment, while exposure to AgNO3 leads to cell erosion in maize root apical meristem. In maize, a significant change in metaxylem count is evident with Citrate-nAg, AgNO3, and ZnSO4 treatment, but not with nZnO treatment (p>0.1). In both maize and cabbage, measures of germination and root elongation reveal lower nanoparticle toxicity compared to free ions. As moisture data do not support osmotically-induced water stress hypothesis for explaining toxicity, we discuss other proximate mechanisms including the potential role of growth hormones and transcription factors. These findings highlight previously overlooked, anatomically significant effects of metal nanoparticles, and recommend considering detailed anatomical investigations in tandem with the standard

  19. Engineering Plant Immunity: Using CRISPR/Cas9 to Generate Virus Resistance

    Directory of Open Access Journals (Sweden)

    Syed Shan-e-ali Zaidi

    2016-11-01

    Full Text Available Plant viruses infect many economically important crops, including wheat, cotton, maize, cassava, and other vegetables. These viruses pose a serious threat to agriculture worldwide, as decreases in cropland area per capita may cause production to fall short of that required to feed the increasing world population. Under these circumstances, conventional strategies can fail to control rapidly evolving and emerging plant viruses. Genome-engineering strategies have recently emerged as promising tools to introduce desirable traits in many eukaryotic species, including plants. Among these genome engineering technologies, the CRISPR (clustered regularly interspaced palindromic repeats/ CRISPR-associated 9 (CRISPR/Cas9 system has received special interest because of its simplicity, efficiency, and reproducibility. Recent studies have used CRISPR/Cas9 to engineer virus resistance in plants, either by directly targeting and cleaving the viral genome, or by modifying the host plant genome to introduce viral immunity. Here, we briefly describe the biology of the CRISPR/Cas9 system and plant viruses, and how different genome engineering technologies have been used to target these viruses. We further describe the main findings from recent studies of CRISPR/Cas9-mediated viral interference and discuss how these findings can be applied to improve global agriculture. We conclude by pinpointing the gaps in our knowledge and the outstanding questions regarding CRISPR/Cas9-mediated viral immunity.

  20. Engineering Plant Immunity: Using CRISPR/Cas9 to Generate Virus Resistance

    KAUST Repository

    Zaidi, Syed Shan-e-Ali

    2016-11-08

    Plant viruses infect many economically important crops, including wheat, cotton, maize, cassava, and other vegetables. These viruses pose a serious threat to agriculture worldwide, as decreases in cropland area per capita may cause production to fall short of that required to feed the increasing world population. Under these circumstances, conventional strategies can fail to control rapidly evolving and emerging plant viruses. Genome-engineering strategies have recently emerged as promising tools to introduce desirable traits in many eukaryotic species, including plants. Among these genome engineering technologies, the CRISPR (clustered regularly interspaced palindromic repeats)/CRISPR-associated 9 (CRISPR/Cas9) system has received special interest because of its simplicity, efficiency, and reproducibility. Recent studies have used CRISPR/Cas9 to engineer virus resistance in plants, either by directly targeting and cleaving the viral genome, or by modifying the host plant genome to introduce viral immunity. Here, we briefly describe the biology of the CRISPR/Cas9 system and plant viruses, and how different genome engineering technologies have been used to target these viruses. We further describe the main findings from recent studies of CRISPR/Cas9-mediated viral interference and discuss how these findings can be applied to improve global agriculture. We conclude by pinpointing the gaps in our knowledge and the outstanding questions regarding CRISPR/Cas9-mediated viral immunity.

  1. Mechanisms of Invasion Resistance of Aquatic Plant Communities

    Science.gov (United States)

    Petruzzella, Antonella; Manschot, Johan; van Leeuwen, Casper H. A.; Grutters, Bart M. C.; Bakker, Elisabeth S.

    2018-01-01

    Invasive plant species are among the major threats to freshwater biodiversity. Few experimental studies have investigated whether native plant diversity can provide biotic resistance to invaders in freshwater ecosystems. At small spatial scales, invasion resistance may increase with plant species richness due to a better use of available resources, leaving less available for a potential invader (Complementarity effect) and/or the greater probability to have a highly competitive (or productive) native species in the community (Selection effect). In submerged aquatic plant communities, we tested the following hypotheses: (1) invader establishment success is greatest in the absence of a native plant community; (2) lower in plant communities with greater native species richness, due to complementary and/or selection effects; and (3) invader establishment success would be lowest in rooted plant communities, based on the limiting similarity theory as the invader is a rooted submerged species. In a greenhouse experiment, we established mesocosms planted with 0 (bare sediment), 1, 2, and 4 submerged plant species native to NW Europe and subjected these to the South African invader Lagarosiphon major (Ridl.) Moss. We used two rooted (Myriophyllum spicatum L., Potamogeton perfoliatus L.) and two non-rooted native species (Ceratophyllum demersum L., Utricularia vulgaris L.) representing two distinct functional groups considering their nutrient acquisition strategy which follows from their growth form, with, respectively, the sediment and water column as their main nutrient source. We found that the presence of native vegetation overall decreased the establishment success of an alien aquatic plant species. The strength of this observed biotic resistance increased with increasing species richness of the native community. Mainly due to a selection effect, the native biomass of mixed communities overyielded, and this further lowered the establishment success of the invader in our

  2. DEVELOPMENT OF MOLECULAR MONITORING TECHNOLOGIES TO MEASURE TRANSGENE FLOW AND INTROGRESSION IN CROP AND NON-CROP PLANT SPECIES

    Science.gov (United States)

    The Gene Flow Project at the US Environmental Protection Agency, Western Ecology Division is developing methodologies for ecological risk assessments of transgene flow using Agrostis and Brassica engineered with CP4 EPSPS genes that confer resistance to glyphosate herbicide. In ...

  3. Impact of insect management on population dynamics and insecticide resistance of tarnished plant bug (Lygus lineolaris)

    Science.gov (United States)

    The tarnished plant bug, Lygus lineolaris (Palisot De Beauvois) is a highly polyphagous insect that feeds on numerous wild and cultivated host plants. Although transgenic crops expressing insecticidal toxins have been available for approximately 20 years for some insect crop pests, none have been d...

  4. Role of plant biotechnology and genetic engineering in crop-improvement, with special emphases on cotton: A review

    International Nuclear Information System (INIS)

    Akhtar, L.H.; Siddiq, S.Z.; Tariq, A.H.; Arshad, M.; Gorham, J.

    2003-01-01

    Plant biotechnology and genetic engineering offer novel approaches to plant-breeding, production, propagation and preservation of germplasm. In this manuscript, the population and food-requirements of Pakistan, role of biotechnology and genetic engineering in crop-improvement, along with potential uses in cotton, have been discussed. The latest position of plant biotechnology and genetic engineering in Pakistan and the advantages of biotechnology and genetic-engineering techniques over conventional plant-breeding techniques, along with critical views of various scientists have been reviewed. (author)

  5. Salt tolerance in crop plants monitored by chlorophyll fluorescence in vivo.

    Science.gov (United States)

    Smillie, R M; Nott, R

    1982-10-01

    The potential of measurements of chlorophyll fluorescence in vivo to detect cellular responses to salinity and degrees of salt stress in leaves was investigated for three crop plants. Sugar beet (Beta vulgaris L.) (salt tolerant), sunflower (Helianthus annuus L.) (moderately salt tolerant), and bean (Phaseolus Vulgaris L. cv Canadian Wonder) (salt intolerant) were grown in pots and watered with mineral nutrient solution containing 100 millimolar NaCl. The fast rise in variable chlorophyll fluorescence yield that is correlated with photoreduction of photosystem II acceptors increased in leaves of sugar beet plants treated with salt suggesting stimulation of photosystem II activity relative to photosystem I. In sunflower, this fast rise was depressed by approximately 25% and the subsequent slow rate of quenching of the chlorophyll fluorescence was stimulated. These differences were more marked in the older mature leaves indicating an increasing gradient of salt response down the plant. The salt effect in vivo was reversible since chloroplasts isolated from mature leaves of salt-treated and control sunflower plants gave similar photosystem II activities. Unlike in sugar beet and sunflower, leaves of salt-treated bean progressively lost chlorophyll. The rate of slow quenching of chlorophyll fluorescence decreased indicating development of a partial block after photosystem II and possible initial stimulation of photosystem II activity. With further loss of chlorophyll photosystem II activity declined. It was concluded that measurements of chlorophyll fluorescence in vivo can provide a rapid means of detecting salt stress in leaves, including instances where photosynthesis is reduced in the absence of visible symptoms. The possible application to screening for salt tolerance is discussed.

  6. Exploring Antibiotic Resistance Genes and Metal Resistance Genes in Plasmid Metagenomes from Wastewater Treatment Plants

    Directory of Open Access Journals (Sweden)

    An-Dong eLi

    2015-09-01

    Full Text Available Plasmids operate as independent genetic elements in microorganism communities. Through horizontal gene transfer, they can provide their host microorganisms with important functions such as antibiotic resistance and heavy metal resistance. In this study, six metagenomic libraries were constructed with plasmid DNA extracted from influent, activated sludge and digested sludge of two wastewater treatment plants. Compared with the metagenomes of the total DNA extracted from the same sectors of the wastewater treatment plant, the plasmid metagenomes had significantly higher annotation rates, indicating that the functional genes on plasmids are commonly shared by those studied microorganisms. Meanwhile, the plasmid metagenomes also encoded many more genes related to defense mechanisms, including ARGs. Searching against an antibiotic resistance genes (ARGs database and a metal resistance genes (MRGs database revealed a broad-spectrum of antibiotic (323 out of a total 618 subtypes and metal resistance genes (23 out of a total 23 types on these plasmid metagenomes. The influent plasmid metagenomes contained many more resistance genes (both ARGs and MRGs than the activated sludge and the digested sludge metagenomes. Sixteen novel plasmids with a complete circular structure that carried these resistance genes were assembled from the plasmid metagenomes. The results of this study demonstrated that the plasmids in wastewater treatment plants could be important reservoirs for resistance genes, and may play a significant role in the horizontal transfer of these genes.

  7. Integrated plant nutrient management on diversified cropping system in aqua-terrestrial ecosystem for yield potentiality, quality and rural sustainability

    OpenAIRE

    PUSTE, ANANDAMOY DR.; DE, PRALAY ER.; MAITY, TAPAN KUMAR DR.

    2009-01-01

    Balanced and integrated plant nutrient management is imperative in agricultural production system including its quality - more applicable to those of developing country in the world. Like arable land in wetland ecosystem, nitrogen and other essential key plant elements and its management is also an integral part for so many beneficial aquatic crops (food, non-food etc.). With this significant importance of IPNM, number of case studies were undertaken through TOT, TDET based integrated aquacul...

  8. Integrating Plant Science and Crop Modeling: Assessment of the Impact of Climate Change on Soybean and Maize Production.

    Science.gov (United States)

    Fodor, Nándor; Challinor, Andrew; Droutsas, Ioannis; Ramirez-Villegas, Julian; Zabel, Florian; Koehler, Ann-Kristin; Foyer, Christine H

    2017-11-01

    Increasing global CO2 emissions have profound consequences for plant biology, not least because of direct influences on carbon gain. However, much remains uncertain regarding how our major crops will respond to a future high CO2 world. Crop model inter-comparison studies have identified large uncertainties and biases associated with climate change. The need to quantify uncertainty has drawn the fields of plant molecular physiology, crop breeding and biology, and climate change modeling closer together. Comparing data from different models that have been used to assess the potential climate change impacts on soybean and maize production, future yield losses have been predicted for both major crops. When CO2 fertilization effects are taken into account significant yield gains are predicted for soybean, together with a shift in global production from the Southern to the Northern hemisphere. Maize production is also forecast to shift northwards. However, unless plant breeders are able to produce new hybrids with improved traits, the forecasted yield losses for maize will only be mitigated by agro-management adaptations. In addition, the increasing demands of a growing world population will require larger areas of marginal land to be used for maize and soybean production. We summarize the outputs of crop models, together with mitigation options for decreasing the negative impacts of climate on the global maize and soybean production, providing an overview of projected land-use change as a major determining factor for future global crop production. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.

  9. Effect of some detergents, humate, and composition of seedbed on crop of tomato plants in a hydroponic culture

    Science.gov (United States)

    Guminka, A. Z.; Gracz-Nalepka, M.; Lukasiewicz, B.; Sobolewicz, E.; Turkiewicz, I. T.

    1978-01-01

    It is established that single detergent doses distinctly stimulate vegetative development of plants in the initial stage when humates are available. When detergents are applied every four weeks in a hydroponic culture, in which the seedbed does not contain active humates, the crop is reduced by 50%. This adverse effect does not occur when the seedbed is a mixture of brown coal and peat.

  10. A review of the use of engineered nanomaterials to suppress plant disease and enhance crop yield

    Energy Technology Data Exchange (ETDEWEB)

    Servin, Alia; Elmer, Wade; Mukherjee, Arnab; Torre-Roche, Roberto De la [The Connecticut Agricultural Experiment Station (United States); Hamdi, Helmi [University of Carthage, Water Research and Technology Center (Tunisia); White, Jason C., E-mail: jason.white@ct.gov [The Connecticut Agricultural Experiment Station (United States); Bindraban, Prem; Dimkpa, Christian [Virtual Fertilizer Research Center (United States)

    2015-02-15

    Nanotechnology has the potential to play a critical role in global food production, food security, and food safety. The applications of nanotechnology in agriculture include fertilizers to increase plant growth and yield, pesticides for pest and disease management, and sensors for monitoring soil quality and plant health. Over the past decade, a number of patents and products incorporating nanomaterials into agricultural practices (e.g., nanopesticides, nanofertilizers, and nanosensors) have been developed. The collective goal of all of these approaches is to enhance the efficiency and sustainability of agricultural practices by requiring less input and generating less waste than conventional products and approaches. This review evaluates the current literature on the use of nanoscale nutrients (metals, metal oxides, carbon) to suppress crop disease and subsequently enhance growth and yield. Notably, this enhanced yield may not only be directly linked to the reduced presence of pathogenic organisms, but also to the potential nutritional value of the nanoparticles themselves, especially for the essential micronutrients necessary for host defense. We also posit that these positive effects are likely a result of the greater availability of the nutrients in the “nano” form. Last, we offer comments on the current regulatory perspective for such applications.

  11. Manipulating photorespiration to increase plant productivity: recent advances and perspectives for crop improvement.

    Science.gov (United States)

    Betti, Marco; Bauwe, Hermann; Busch, Florian A; Fernie, Alisdair R; Keech, Olivier; Levey, Myles; Ort, Donald R; Parry, Martin A J; Sage, Rowan; Timm, Stefan; Walker, Berkley; Weber, Andreas P M

    2016-05-01

    Recycling of the 2-phosphoglycolate generated by the oxygenase reaction of Rubisco requires a complex and energy-consuming set of reactions collectively known as the photorespiratory cycle. Several approaches aimed at reducing the rates of photorespiratory energy or carbon loss have been proposed, based either on screening for natural variation or by means of genetic engineering. Recent work indicates that plant yield can be substantially improved by the alteration of photorespiratory fluxes or by engineering artificial bypasses to photorespiration. However, there is also evidence indicating that, under certain environmental and/or nutritional conditions, reduced photorespiratory capacity may be detrimental to plant performance. Here we summarize recent advances obtained in photorespiratory engineering and discuss prospects for these advances to be transferred to major crops to help address the globally increasing demand for food and biomass production. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  12. Chemical Processing of Non-Crop Plants for Jet Fuel Blends Production

    Science.gov (United States)

    Kulis, M. J.; Hepp, A. F.; McDowell, M.; Ribita, D.

    2009-01-01

    The use of Biofuels has been gaining in popularity over the past few years due to their ability to reduce the dependence on fossil fuels. Biofuels as a renewable energy source can be a viable option for sustaining long-term energy needs if they are managed efficiently. We describe our initial efforts to exploit algae, halophytes and other non-crop plants to produce synthetics for fuel blends that can potentially be used as fuels for aviation and non-aerospace applications. Our efforts have been dedicated to crafting efficient extraction and refining processes in order to extract constituents from the plant materials with the ultimate goal of determining the feasibility of producing biomass-based jet fuel from the refined extract. Two extraction methods have been developed based on communition processes, and liquid-solid extraction techniques. Refining procedures such as chlorophyll removal and transesterification of triglycerides have been performed. Gas chromatography in tandem with mass spectroscopy is currently being utilized in order to qualitatively determine the individual components of the refined extract. We also briefly discuss and compare alternative methods to extract fuel-blending agents from alternative biofuels sources.

  13. A review of the use of engineered nanomaterials to suppress plant disease and enhance crop yield

    International Nuclear Information System (INIS)

    Servin, Alia; Elmer, Wade; Mukherjee, Arnab; Torre-Roche, Roberto De la; Hamdi, Helmi; White, Jason C.; Bindraban, Prem; Dimkpa, Christian

    2015-01-01

    Nanotechnology has the potential to play a critical role in global food production, food security, and food safety. The applications of nanotechnology in agriculture include fertilizers to increase plant growth and yield, pesticides for pest and disease management, and sensors for monitoring soil quality and plant health. Over the past decade, a number of patents and products incorporating nanomaterials into agricultural practices (e.g., nanopesticides, nanofertilizers, and nanosensors) have been developed. The collective goal of all of these approaches is to enhance the efficiency and sustainability of agricultural practices by requiring less input and generating less waste than conventional products and approaches. This review evaluates the current literature on the use of nanoscale nutrients (metals, metal oxides, carbon) to suppress crop disease and subsequently enhance growth and yield. Notably, this enhanced yield may not only be directly linked to the reduced presence of pathogenic organisms, but also to the potential nutritional value of the nanoparticles themselves, especially for the essential micronutrients necessary for host defense. We also posit that these positive effects are likely a result of the greater availability of the nutrients in the “nano” form. Last, we offer comments on the current regulatory perspective for such applications

  14. Production characteristics of lettuce Lactuca sativa L. in the frame of the first crop tests in the Higher Plant Chamber integrated into the MELiSSA Pilot Plant

    Science.gov (United States)

    Tikhomirova, Natalia; Lawson, Jamie; Stasiak, Michael; Dixon, Mike; Paille, Christel; Peiro, Enrique; Fossen, Arnaud; Godia, Francesc

    Micro-Ecological Life Support System Alternative (MELiSSA) is an artificial closed ecosystem that is considered a tool for the development of a bioregenerative life support system for manned space missions. One of the five compartments of MELiSSA loop -Higher Plant Chamber was recently integrated into the MELiSSA Pilot Plant facility at Universitat Aut`noma deo Barcelona. The main contributions expected by integration of this photosynthetic compartment are oxygen, water, vegetable food production and CO2 consumption. Production characteristics of Lactuca sativa L., as a MELiSSA candidate crop, were investigated in this work in the first crop experiments in the MELiSSA Pilot Plant facility. The plants were grown in batch culture and totaled 100 plants with a growing area 5 m long and 1 m wide in a sealed controlled environment. Several replicates of the experiments were carried out with varying duration. It was shown that after 46 days of lettuce cultivation dry edible biomass averaged 27, 2 g per plant. However accumulation of oxygen in the chamber, which required purging of the chamber, and decrease in the food value of the plants was observed. Reducing the duration of the tests allowed uninterrupted test without opening the system and also allowed estimation of the crop's carbon balance. Results of productivity, tissue composition, nutrient uptake and canopy photosynthesis of lettuce regardless of test duration are discussed in the paper.

  15. RNAi technology extends its reach: Engineering plant resistance ...

    African Journals Online (AJOL)

    RNA interference (RNAi) is a homology-dependent gene silencing technology that is initiated by double stranded RNA (dsRNA). It has emerged as a genetic tool for engineering plants resistance against prokaryotic pathogens such as virus and bacteria. Recent studies broaden the role of RNAi, and many successful ...

  16. The use of refuge in host plant resistance systems for the control of virulent biotype adaptation in the soybean aphid (Hemiptera: Aphididae.

    Science.gov (United States)

    Wenger, Jacob; Ramstad, Monica; Mian, M A Rouf; Michel, Andy

    2014-08-01

    Host plant resistant (HPR) crop varieties offer control of many insect pest species. However, the evolution of virulent biotypes capable of overcoming plant resistance poses challenges for the implementation of HPR. Widespread planting of HPR crops further reduces HPR efficacy by increasing selection pressure on pests, favoring the rapid proliferation of virulence. An analogous situation occurs in managing insect resistance to transgenic Bt crops, where planting of susceptible refuges effectively delays the evolution and spread of Bt resistance. We investigated the applicability of susceptible refuges in HPR as a tactic to manage virulent biotypes, using the soybean aphid (Aphis glycines Matsumura) as a model system. The virulent biotype 3 and avirulent biotype 1 were reared in greenhouse microcosms using a variety of refuge size, HPR gene, and biotype mixture treatments, allowing us to discern how the presence of a refuge alters the relative fitness and movement of biotypes both by themselves and in competition. The virulent biotype had greater relative fitness in 10 of 12 tested microcosms, with the greatest advantage observed in refuge-free microcosms. In microcosms with a refuge, avirulent fitness increased significantly as these biotypes moved to and used refuge plants. When the two biotypes were reared in the same microcosm, biotype 3's fitness increased significantly relative to when reared in isolation, while biotype 1's fitness was slightly, but not significantly, increased. Our findings suggested that while susceptible refuges would be incapable of reversing the proliferation of virulent biotypes, they could slow the spread of virulence by maintaining avirulence.

  17. Effect of zone and crops rotation on Ischaemum rugosum and resistance to bispyribac-sodium in Ariari, Colombia

    OpenAIRE

    Plaza, G.; Hernández, F.A.

    2014-01-01

    The objectives of this research were to evaluate (1) weed species presented in rice fields in relation to the geographical zone and crop rotation and (2) the resistance level of Ischaemum rugosum to the herbicide bispyribac-sodium. For the first objective, were sampled 79 commercial fields of rice to establish weed density, coverage, and rotation system in the evaluated fields with record of bispyribac-sodium application of at least five years. To reach the second objective, the seeds were co...

  18. The Effect of Plant Cultivar, Growth Media, Harvest Method and Post Harvest Treatment on the Microbiology of Edible Crops

    Science.gov (United States)

    Hummerick, Mary P.; Gates, Justin R.; Nguyen, Bao-Thang; Massa, Gioia D.; Wheeler, Raymond M.

    2011-01-01

    Systems for the growth of crops in closed environments are being developed and tested for potential use in space applications to provide a source of fresh food. Plant growth conditions, growth media composition and harvest methods can have an effect on the microbial population of the plant, and therefore should be considered along with the optimization of plant growth and harvest yields to ensure a safe and palatable food crop. This work examines the effect of plant cultivar, growth media, and harvest method on plant microbial populations. Twelve varieties of leafy greens and herbs were grown on a mixture of Fafard #2 and Arcillite in the pillow root containment system currently being considered for the VEGGIE plant growth unit developed by Orbitec. In addition, ,Sierra and Outredgeous lettuce varieties were grown in three different mixtures (Fafard #2, Ardllite, and Perlite/Vermiculite). The plants were analyzed for microbial density. Two harvest methods, "cut and come again" (CACA) and terminal harvest were also compared. In one set ofexpe'riments red leaf lettuce and mizuna were grown in pots in a Biomass Production System for education. Plants were harvested every two weeks by either method. Another set of experiments was performed using the rooting pillows to grow 5 varieties of leafy greens and cut harvesting at different intervals. Radishes were harvested and replanted at two-week intervals. Results indicate up to a 3 IOglO difference in microbial counts between some varieties of plants. Rooting medium resulted in an approximately 2 IOglO lower count in the lettuce grown in arscillite then those grown in the other mixtures. Harvest method and frequency had less impact on microbial counts only showing a significant increase in one variety of plant. Post harvest methods to decrease the bacterial counts on edible crops were investigated in these and other experiments. The effectiveness of PRO-SAN and UV-C radiation is compared.

  19. Mulching as a countermeasure for crop contamination within the 30 km zone of Chernobyl Nuclear Power Plant

    International Nuclear Information System (INIS)

    Yera, T.S.; Vallejo, R.; Tent, J.; Rauret, G.; Omelyanenko, N.; Ivanov, Y.

    1999-01-01

    The effect of mulch soil cover on crop contamination by 137 Cs was studied within the 30 km zone of Chernobyl Nuclear Power Plant. Experiments were performed with oats (Avena sativa) over a three year period. In 1992 soil surface was covered by a plastic net. In 1993 two straw mulch treatments were applied at a dose rate of 200 g m -2 using 137 Cs contaminated and clean straw, respectively. A similar mulch treatment was applied in 1994, and two mulch doses of clean straw were tested. Protection of the soil with a plastic net significantly increased crop yield and reduced crop contamination. When clean straw was used as a mulch layer, a significant decrease of about 30--40% in 137 Cs activity concentration was observed. Mulching with 137 Cs contaminated straw did not reduce crop contamination, probably due to an increase in soil available 137 Cs released from the contaminated mulch. Mulching has been shown to be an effective treatment both for reducing 137 Cs plant contamination and improving crop yield. Therefore, it can be considered as a potential countermeasure in a post-accident situation

  20. Distribution of nitrogen ammonium sulfate (15N) soil-plant system in a no-tillage crop succession

    International Nuclear Information System (INIS)

    Fernandes, Flavia Carvalho da Silva; Libardi, Paulo Leonel

    2012-01-01

    the n use by maize (Zea mays, l.) is affected by n-fertilizer levels. this study was conducted using a sandy-clay texture soil (Hapludox) to evaluate the efficiency of n use by maize in a crop succession, based on 15 N labeled ammonium sulfate (5.5 atom %) at different rates, and to assess the residual fertilizer effect in two no-tillage succession crops (signal grass and corn). Two maize crops were evaluated, the first in the growing season 2006, the second in 2007, and brachiaria in the second growing season. The treatments consisted of n rates of 60, 120 and 180 kg ha -1 in the form of labeled 15 N ammonium sulfate. This fertilizer was applied in previously defined subplots, only to the first maize crop (growing season 2006). The variables total accumulated n; fertilizer-derived n in corn plants and pasture; fertilizer-derived n in the soil; and recovery of fertilizer-n by plants and soil were evaluated.The highest uptake of fertilizer n by corn was observed after application of 120 kg ha -1 N and the residual effect of n fertilizer on subsequent corn and brachiaria was highest after application of 180 kg ha -1 N. After the crop succession, soil n recovery was 32, 23 and 27 % for the respective applications of 60, 120 and 180 kg ha -1 N. (author)

  1. Seed treatments with thiamine reduce the performance of generalist and specialist aphids on crop plants.

    Science.gov (United States)

    Hamada, A M; Fatehi, J; Jonsson, L M V

    2018-02-01

    Thiamine is a vitamin that has been shown to act as a trigger to activate plant defence and reduce pathogen and nematode infection as well as aphid settling and reproduction. We have here investigated whether thiamine treatments of seeds (i.e. seed dressing) would increase plant resistance against aphids and whether this would have different effects on a generalist than on specialist aphids. Seeds of wheat, barley, oat and pea were treated with thiamine alone or in combination with the biocontrol bacteria Pseudomonas chlororaphis MA 342 (MA 342). Plants were grown in climate chambers. The effects of seed treatment on fecundity, host acceptance and life span were studied on specialist aphids bird cherry-oat aphid (Rhopalosiphum padi L.) and pea aphid (Acyrthosiphon pisum Harris) and on the generalist green peach aphid (Myzus persicae, Sulzer). Thiamine seed treatments reduced reproduction and host acceptance of all three aphid species. The number of days to reproduction, the length of the reproductive life, the fecundity and the intrinsic rate of increase were found reduced for bird cherry-oat aphid after thiamine treatment of the cereal seeds. MA 342 did not have any effect in any of the plant-aphid combinations, except a weak decrease of pea aphid reproduction on pea. The results show that there are no differential effects of either thiamine or MA 342 seed treatments on specialist and generalist aphids and suggest that seed treatments with thiamine has a potential in aphid pest management.

  2. Effect of crop growth and canopy filtration on the dynamics of plant disease epidemics spread by aerially dispersed spores.

    Science.gov (United States)

    Ferrandino, F J

    2008-05-01

    Most mathematical models of plant disease epidemics ignore the growth and phenology of the host crop. Unfortunately, reports of disease development are often not accompanied by a simultaneous and commensurate evaluation of crop development. However, the time scale for increases in the leaf area of field crops is comparable to the time scale of epidemics. This simultaneous development of host and pathogen has many ramifications on the resulting plant disease epidemic. First, there is a simple dilution effect resulting from the introduction of new healthy leaf area with time. Often, measurements of disease levels are made pro rata (per unit of host leaf area or total root length or mass). Thus, host growth will reduce the apparent infection rate. A second, related effect, has to do with the so-called "correction factor," which accounts for inoculum falling on already infected tissue. This factor accounts for multiple infection and is given by the fraction of the host tissue that is susceptible to disease. As an epidemic develops, less and less tissue is open to infection and the initial exponential growth slows. Crop growth delays the impact of this limiting effect and, therefore, tends to increase the rate of disease progress. A third and often neglected effect arises when an increase in the density of susceptible host tissue results in a corresponding increase in the basic reproduction ratio, R(0), defined as the ratio of the total number of daughter lesions produced to the number of original mother lesions. This occurs when the transport efficiency of inoculum from infected to susceptible host is strongly dependent on the spatial density of plant tissue. Thus, crop growth may have a major impact on the development of plant disease epidemics occurring during the vegetative phase of crop growth. The effects that these crop growth-related factors have on plant disease epidemics spread by airborne spores are evaluated using mathematical models and their importance is

  3. Energy crops for biogas plants. Baden-Wuerttemberg; Energiepflanzen fuer Biogasanlagen. Baden-Wuerttemberg

    Energy Technology Data Exchange (ETDEWEB)

    Butz, A.; Heiermann, M.; Herrmann, C. [and others

    2013-05-01

    For agriculturists in Baden-Wuerttemberg (Federal Republic of Germany), the brochure under consideration provides recommendations on alternative crop rotation systems. With the help of these alternative cultivation systems, crop rotation with high yields in combination with high diversity, diversification and sustainability can be realized. Subsequently to the presentation of energy crops for the production of biogas, recommendations for the design of crop rotation are given. Other chapters of this booklet deal with ensilage and gas yields as well as the economics of energy crop cultivation.

  4. Energy crops for biogas plants. Mecklenburg-Western Pomerania; Energiepflanzen fuer Biogasanlagen. Mecklenburg-Vorpommern

    Energy Technology Data Exchange (ETDEWEB)

    Aurbacher, J.; Bull, I.; Formowitz, B. (and others)

    2012-06-15

    For agriculturists in Mecklenburg-Western Pomerania (Federal Republic of Germany), the brochure under consideration provides recommendations on alternative crop rotation systems. With the help of these alternative cultivation systems, crop rotation with high yields in combination with high diversity, diversification and sustainability can be realized. Subsequently to the presentation of energy crops for the production of biogas, recommendations for the design of crop rotation are given. Other chapters of this booklet deal with ensilage and gas yields as well as the economics of energy crop cultivation.

  5. Energy crops for biogas plants. Saxony-Anhalt; Energiepflanzen fuer Biogasanlagen. Sachsen-Anhalt

    Energy Technology Data Exchange (ETDEWEB)

    Boese, L.; Buttlar, C. von; Boettcher, K. (and others)

    2012-07-15

    For agriculturists in Saxony-Anhalt (Federal Republic of Germany), the brochure under consideration provides recommendations on alternative crop rotation systems. With the help of these alternative cultivation systems, crop rotation with high yields in combination with high diversity, diversification and sustainability can be realized. Subsequently to the presentation of energy crops for the production of biogas, recommendations for the design of crop rotation are given. Other chapters of this booklet deal with ensilage and gas yields as well as the economics of energy crop cultivation.

  6. Molecular breeding for virus resistance : an applied approach in vegetable crops

    NARCIS (Netherlands)

    Gielen, J.J.L.

    1995-01-01

    Viral diseases cause significant economic losses in most, if not all, crop species throughout the world. Total cost is not only restricted to reduction in crop yield and quality, but also include the development and application of a wide array of disease control measures. Routinely employed

  7. Basis for the development of a scenario for ground water risk assessment of plant protection products to banana crop in the frame work of regulation 1107/2009

    Science.gov (United States)

    Alonso-Prados, Elena; Fernández-Getino, Ana Patricia; Alonso-Prados, Jose Luis

    2014-05-01

    The risk assessment to ground water of pesticides and their main metabolites is a data requirement under regulation 1107/2009, concerning the placing of plant protection products on the market. Predicted environmental concentrations (PEC) are calculated according to the recommendations of Forum for the Co-ordination of pesticide fate models and Their Use (FOCUS). The FOCUS groundwater working group developed scenarios for the main crops in European Union. However there are several crops which grow under specific agro-environmental conditions not covered by these scenarios and it is frequent to use the defined scenarios as surrogates. This practice adds an uncertainty factor in the risk assessment. One example is represented by banana crop which in Europe is limited to sub-tropical environmental conditions and with specific agronomic practices. The Canary Islands concentrates the higher production of banana in the European Union characterized by volcanic soils. Banana is located at low altitudes where soils have been eroded or degraded, and it is a common practice to transport soil materials from the high-mid altitudes to the low lands for cultivation. These cultivation plots are locally named "sorribas". These volcanic soils, classified as Andosols according to the FAO classification, have special physico-chemical properties due to noncrystalline materials and layer silicates. The good stability of these soils and their high permeability to water make them relatively resistant to water erosion. Physical properties of volcanic clayey soils are strongly affected by allophone and Fe and Al oxyhidroxides. The rapid weathering of porous volcanic material results in accumulation of stable organo-mineral complexes and short-range-order mineral such as allophane, imogolite and ferrihydrite. These components induce strong aggregation that partly favors properties such as: reduced swelling, increased aggregate stability of clay minerals, high soil water retention capacity

  8. Evaluation of developmental responses of two crop plants exposed to silver and zinc oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Pokhrel, Lok R. [Department of Environmental Health, College of Public Health, East Tennessee State University, Johnson City, TN 37614–1700 (United States); Dubey, Brajesh, E-mail: bdubey@uoguelph.ca [Environmental Engineering, School of Engineering, University of Guelph, 50 Stone Road East, Guelph, Ontario (Canada)

    2013-05-01

    The increasing applications of different nanomaterials in the myriad of nano-enabled products and their potential for leaching have raised considerable environmental, health and safety (EHS) concerns. As systematic studies investigating potential anomalies in the morphology and anatomy of crop plants are scarce, herein we report on the developmental responses of two agriculturally significant crop plants, maize (Zea mays L.) and cabbage (Brassica oleracea var. capitata L.), upon in vitro exposure to nanoparticles of citrate-coated silver (Citrate–nAg) and zinc oxide (nZnO). Analyses involve histology of the primary root morphology and anatomy using light microscopy, metal biouptake, moisture content, rate of germination, and root elongation. Comparative toxicity profiles of the ionic salts (AgNO{sub 3} and ZnSO{sub 4}) are developed. Notably, we uncover structural changes in maize primary root cells upon exposure to Citrate–nAg, nZnO, AgNO{sub 3}, and ZnSO{sub 4}, possibly due to metal biouptake, suggesting potential for functional impairments in the plant growth and development. Citrate–nAg exposure results in lower Ag biouptake compared to AgNO{sub 3} treatment in maize. Microscopic evidence reveals ‘tunneling-like effect’ with nZnO treatment, while exposure to AgNO{sub 3} leads to cell erosion in maize root apical meristem. In maize, a significant change in metaxylem count is evident with Citrate–nAg, AgNO{sub 3}, and ZnSO{sub 4} treatment, but not with nZnO treatment (p > 0.1). In both maize and cabbage, measures of germination and root elongation reveal lower nanoparticle toxicity compared to free ions. As moisture data do not support osmotically-induced water stress hypothesis for explaining toxicity, we discuss other proximate mechanisms including the potential role of growth hormones and transcription factors. These findings highlight previously overlooked, anatomically significant effects of metal nanoparticles, and recommend considering

  9. Biofertilizers function as key player in sustainable agriculture by improving soil fertility, plant tolerance and crop productivity

    Science.gov (United States)

    2014-01-01

    Current soil management strategies are mainly dependent on inorganic chemical-based fertilizers, which caused a serious threat to human health and environment. The exploitation of beneficial microbes as a biofertilizer has become paramount importance in agriculture sector for their potential role in food safety and sustainable crop production. The eco-friendly approaches inspire a wide range of application of plant growth promoting rhizobacteria (PGPRs), endo- and ectomycorrhizal fungi, cyanobacteria and many other useful microscopic organisms led to improved nutrient uptake, plant growth and plant tolerance to abiotic and biotic stress. The present review highlighted biofertilizers mediated crops functional traits such as plant growth and productivity, nutrient profile, plant defense and protection with special emphasis to its function to trigger various growth- and defense-related genes in signaling network of cellular pathways to cause cellular response and thereby crop improvement. The knowledge gained from the literature appraised herein will help us to understand the physiological bases of biofertlizers towards sustainable agriculture in reducing problems associated with the use of chemicals fertilizers. PMID:24885352

  10. Biofertilizers function as key player in sustainable agriculture by improving soil fertility, plant tolerance and crop productivity.

    Science.gov (United States)

    Bhardwaj, Deepak; Ansari, Mohammad Wahid; Sahoo, Ranjan Kumar; Tuteja, Narendra

    2014-05-08

    Current soil management strategies are mainly dependent on inorganic chemical-based fertilizers, which caused a serious threat to human health and environment. The exploitation of beneficial microbes as a biofertilizer has become paramount importance in agriculture sector for their potential role in food safety and sustainable crop production. The eco-friendly approaches inspire a wide range of application of plant growth promoting rhizobacteria (PGPRs), endo- and ectomycorrhizal fungi, cyanobacteria and many other useful microscopic organisms led to improved nutrient uptake, plant growth and plant tolerance to abiotic and biotic stress. The present review highlighted biofertilizers mediated crops functional traits such as plant growth and productivity, nutrient profile, plant defense and protection with special emphasis to its function to trigger various growth- and defense-related genes in signaling network of cellular pathways to cause cellular response and thereby crop improvement. The knowledge gained from the literature appraised herein will help us to understand the physiological bases of biofertlizers towards sustainable agriculture in reducing problems associated with the use of chemicals fertilizers.

  11. Plant perception and response to the signal in gravity resistance

    Science.gov (United States)

    Hoson, Takayuki; Soga, Kouichi; Wakabayashi, Kazuyuki; Kamisaka, Seiichiro; Zhang, Yan; Otomi, Yasuhiro; Hashimoto, Takashi; Iida, Hidetoshi

    2012-07-01

    Gravity resistance, mechanical resistance to the gravitational force, is a principal graviresponse in plants, distinct from gravitropism. Plants increase the rigidity of their cell walls in the final step of gravity resistance. We studied cellular events leading to or related to the cell wall changes under hypergravity conditions produced by centrifugation and under microgravity conditions in space. The involvement of mechanosensitive ion channels (mechanoreceptors) in signal perception in gravity resistance has been suggested by experiments with inhibitors. As a candidate for the mechanoreceptor, we identified MCA1 and MCA2 in Arabidopsis. mca-null and MCA-overexpressing seedlings were normal in growth in the dark at 1 g. However, suppression by hypergravity of elongation growth was reduced in hypocotyls of mca-null seedlings. On the contrary, MCA-overexpressing seedlings were hypersensitive to hypergravity. These results suggest that MCAs act as the mechanoreceptor in signal perception of gravity resistance. Cortical microtubules play an essential role in maintenance of normal growth phenotype under hypergravity conditions. In Space Seed experiment in the Kibo Module (PI: S. Kamisaka), we examined the effects of microgravity on growth phenotypes of Arabidopsis tubulin mutant, tua6. Inflorescences of the mutant emerged earlier and elongated rapidly under microgravity conditions than under on-orbit or ground 1 g conditions. Also, the inflorescences grown under microgravity conditions showed higher cell wall extensibilities than the controls. The tubulin mutant thus grew and developed more or less normally under microgravity conditions, supporting the principal role of microtubules also in plant resistance to 1 g gravity. On the other hand, the cellular osmotic properties, as well as the cell wall properties, are important factors determining the rigidity of plant body. Azuki bean epicotyls were capable of maintaining osmoregulation even under hypergravity

  12. Endophyte-assisted promotion of biomass production and metal-uptake of energy crop sweet sorghum by plant-growth-promoting endophyte Bacillus sp. SLS18

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Shenglian; Xu, Taoying; Chen, Liang [Hunan Univ., Changsha (China). College of Environmental Science and Engineering] [and others

    2012-02-15

    The effects of Bacillus sp. SLS18, a plant-growth-promoting endophyte, on the biomass production and Mn/Cd uptake of sweet sorghum (Sorghum bicolor L.), Phytolacca acinosa Roxb., and Solanum nigrum L. were investigated. SLS18 displayed multiple heavy metals and antibiotics resistances. The strain also exhibited the capacity of producing indole-3-acetic acid, siderophores, and 1-aminocyclopropane-1-carboxylic acid deaminase. In pot experiments, SLS18 could not only infect plants effectively but also significantly increase the biomass of the three tested plants in the presence of Mn/Cd. The promoting effect order of SLS18 on the biomass of the tested plants was sweet sorghum > P. acinosa > S. nigrum L. In the presence of Mn (2,000 mg kg{sup -1}) and Cd (50 mg kg{sup -1}) in vermiculite, the total Mn/Cd uptakes in the aerial parts of sweet sorghum, P. acinosa, and S. nigrum L. were increased by 65.2%/40.0%, 55.2%/31.1%, and 18.6%/25.6%, respectively, compared to the uninoculated controls. This demonstrates that the symbiont of SLS18 and sweet sorghum has the potential of improving sweet sorghum biomass production and its total metal uptake on heavy metal-polluted marginal land. It offers the potential that heavy metal-polluted marginal land could be utilized in planting sweet sorghum as biofuel feedstock for ethanol production, which not only gives a promising phytoremediation strategy but also eases the competition for limited fertile farmland between energy crops and food crops. (orig.)

  13. Endophyte-assisted promotion of biomass production and metal-uptake of energy crop sweet sorghum by plant-growth-promoting endophyte Bacillus sp. SLS18.

    Science.gov (United States)

    Luo, Shenglian; Xu, Taoying; Chen, Liang; Chen, Jueliang; Rao, Chan; Xiao, Xiao; Wan, Yong; Zeng, Guangming; Long, Fei; Liu, Chengbin; Liu, Yutang

    2012-02-01

    The effects of Bacillus sp. SLS18, a plant-growth-promoting endophyte, on the biomass production and Mn/Cd uptake of sweet sorghum (Sorghum bicolor L.), Phytolacca acinosa Roxb., and Solanum nigrum L. were investigated. SLS18 displayed multiple heavy metals and antibiotics resistances. The strain also exhibited the capacity of producing indole-3-acetic acid, siderophores, and 1-aminocyclopropane-1-carboxylic acid deaminase. In pot experiments, SLS18 could not only infect plants effectively but also significantly increase the biomass of the three tested plants in the presence of Mn/Cd. The promoting effect order of SLS18 on the biomass of the tested plants was sweet sorghum > P. acinosa > S. nigrum L. In the presence of Mn (2,000 mg kg(-1)) and Cd (50 mg kg(-1)) in vermiculite, the total Mn/Cd uptakes in the aerial parts of sweet sorghum, P. acinosa, and S. nigrum L. were increased by 65.2%/40.0%, 55.2%/31.1%, and 18.6%/25.6%, respectively, compared to the uninoculated controls. This demonstrates that the symbiont of SLS18 and sweet sorghum has the potential of improving sweet sorghum biomass production and its total metal uptake on heavy metal-polluted marginal land. It offers the potential that heavy metal-polluted marginal land could be utilized in planting sweet sorghum as biofuel feedstock for ethanol production, which not only gives a promising phytoremediation strategy but also eases the competition for limited fertile farmland between energy crops and food crops.

  14. Mining Halophytes for Plant Growth-Promoting Halotolerant Bacteria to Enhance the Salinity Tolerance of Non-halophytic Crops

    Directory of Open Access Journals (Sweden)

    Hassan Etesami

    2018-02-01

    Full Text Available Salinity stress is one of the major abiotic stresses limiting crop production in arid and semi-arid regions. Interest is increasing in the application of PGPRs (plant growth promoting rhizobacteria to ameliorate stresses such as salinity stress in crop production. The identification of salt-tolerant, or halophilic, PGPRs has the potential to promote saline soil-based agriculture. Halophytes are a useful reservoir of halotolerant bacteria with plant growth-promoting capabilities. Here, we review recent studies on the use of halophilic PGPRs to stimulate plant growth and increase the tolerance of non-halophytic crops to salinity. These studies illustrate that halophilic PGPRs from the rhizosphere of halophytic species can be effective bio-inoculants for promoting the production of non-halophytic species in saline soils. These studies support the viability of bioinoculation with halophilic PGPRs as a strategy for the sustainable enhancement of non-halophytic crop growth. The potential of this strategy is discussed within the context of ensuring sustainable food production for a world with an increasing population and continuing climate change. We also explore future research needs for using halotolerant PGPRs under salinity stress.

  15. Exploring antibiotic resistance genes and metal resistance genes in plasmid metagenomes from wastewater treatment plants

    OpenAIRE

    Li, An-Dong; Li, Li-Guan; Zhang, Tong

    2015-01-01

    Plasmids operate as independent genetic elements in microorganism communities. Through horizontal gene transfer, they can provide their host microorganisms with important functions such as antibiotic resistance and heavy metal resistance. In this study, six metagenomic libraries were constructed with plasmid DNA extracted from influent, activated sludge and digested sludge of two wastewater treatment plants. Compared with the metagenomes of the total DNA extracted from the same sectors of the...

  16. A review on the complexity of insect-plant interactions under varying levels of resources and host resistance: the case of Myzus persicae-Prunus persica

    Directory of Open Access Journals (Sweden)

    Verdugo, JA.

    2016-01-01

    Full Text Available Introduction. Insect-plant interactions are affected directly or indirectly by stress factors. The effect of environmental resource availability on insect-plant interactions is here reviewed. Subsequently, the analysis focuses on aphid-host plant interactions, particularly in the system composed by the green peach aphid Myzus persicae and its primary host plant Prunus persica. Literature. Plant defenses arise in two ways: resistance and tolerance, both are affected by abiotic factors. The information gathered from studies (n = 29 on plant-aphid interactions addressing the reduction in water availability on plant resistance, showed that in 41,4% of the studies, drought stress elicits lower resistance, while 34.5%, 20.1% and 3.4%, showed higher, no change and conditional effects on plant resistance, respectively. Conclusions. Water stress elicits mixed effects on plant resistance to aphids. However, the literature review also suggests that cultural practices play a role in the fate of the peach-aphid interactions, whereas the development of predictive models aimed to assist crop-pest management systems still requires more basic information. Aphid responses to plant defenses under stressed conditions are still largely unexplored.

  17. Enhanced whitefly resistance in transgenic tobacco plants expressing double stranded RNA of v-ATPase A gene.

    Directory of Open Access Journals (Sweden)

    Nidhi Thakur

    Full Text Available BACKGROUND: Expression of double strand RNA (dsRNA designed against important insect genes in transgenic plants have been shown to give protection against pests through RNA interference (RNAi, thus opening the way for a new generation of insect-resistant crops. We have earlier compared the efficacy of dsRNAs/siRNAs, against a number of target genes, for interference in growth of whitefly (Bemisia tabaci upon oral feeding. The v-ATPase subunit A (v-ATPaseA coding gene was identified as a crucial target. We now report the effectiveness of transgenic tobacco plants expressing siRNA to silence v-ATPaseA gene expression for the control of whitefly infestation. METHODOLOGY/PRINCIPAL FINDINGS: Transgenic tobacco lines were developed for the expression of long dsRNA precursor to make siRNA and knock down the v-ATPaseA mRNA in whitefly. Molecular analysis and insecticidal properties of the transgenic plants established the formation of siRNA targeting the whitefly v-ATPaseA, in the leaves. The transcript level of v-ATPaseA in whiteflies was reduced up to 62% after feeding on the transgenic plants. Heavy infestation of whiteflies on the control plants caused significant loss of sugar content which led to the drooping of leaves. The transgenic plants did not show drooping effect. CONCLUSIONS/SIGNIFICANCE: Host plant derived pest resistance was achieved against whiteflies by genetic transformation of tobacco which generated siRNA against the whitefly v-ATPaseA gene. Transgenic tobacco lines expressing dsRNA of v-ATPaseA, delivered sufficient siRNA to whiteflies feeding on them, mounting a significant silencing response, leading to their mortality. The transcript level of the target gene was reduced in whiteflies feeding on transgenic plants. The strategy can be taken up for genetic engineering of plants to control whiteflies in field crops.

  18. Enhanced whitefly resistance in transgenic tobacco plants expressing double stranded RNA of v-ATPase A gene.

    Science.gov (United States)

    Thakur, Nidhi; Upadhyay, Santosh Kumar; Verma, Praveen C; Chandrashekar, Krishnappa; Tuli, Rakesh; Singh, Pradhyumna K

    2014-01-01

    Expression of double strand RNA (dsRNA) designed against important insect genes in transgenic plants have been shown to give protection against pests through RNA interference (RNAi), thus opening the way for a new generation of insect-resistant crops. We have earlier compared the efficacy of dsRNAs/siRNAs, against a number of target genes, for interference in growth of whitefly (Bemisia tabaci) upon oral feeding. The v-ATPase subunit A (v-ATPaseA) coding gene was identified as a crucial target. We now report the effectiveness of transgenic tobacco plants expressing siRNA to silence v-ATPaseA gene expression for the control of whitefly infestation. Transgenic tobacco lines were developed for the expression of long dsRNA precursor to make siRNA and knock down the v-ATPaseA mRNA in whitefly. Molecular analysis and insecticidal properties of the transgenic plants established the formation of siRNA targeting the whitefly v-ATPaseA, in the leaves. The transcript level of v-ATPaseA in whiteflies was reduced up to 62% after feeding on the transgenic plants. Heavy infestation of whiteflies on the control plants caused significant loss of sugar content which led to the drooping of leaves. The transgenic plants did not show drooping effect. Host plant derived pest resistance was achieved against whiteflies by genetic transformation of tobacco which generated siRNA against the whitefly v-ATPaseA gene. Transgenic tobacco lines expressing dsRNA of v-ATPaseA, delivered sufficient siRNA to whiteflies feeding on them, mounting a significant silencing response, leading to their mortality. The transcript level of the target gene was reduced in whiteflies feeding on transgenic plants. The strategy can be taken up for genetic engineering of plants to control whiteflies in field crops.

  19. A novel gene of Kalanchoe daigremontiana confers plant drought resistance.

    Science.gov (United States)

    Wang, Li; Zhu, Chen; Jin, Lin; Xiao, Aihua; Duan, Jie; Ma, Luyi

    2018-02-07

    Kalanchoe (K.) daigremontiana is important for studying asexual reproduction under different environmental conditions. Here, we describe a novel KdNOVEL41 (KdN41) gene that may confer drought resistance and could thereby affect K. daigremontiana development. The detected subcellular localization of a KdN41/Yellow Fluorescent Protein (YFP) fusion protein was in the nucleus and cell membrane. Drought, salt, and heat stress treatment in tobacco plants containing the KdN41 gene promoter driving β-glucuronidase (GUS) gene transcription revealed that only drought stress triggered strong GUS staining in the vascular tissues. Overexpression (OE) of the KdN41 gene conferred improved drought resistance in tobacco plants compared to wild-type and transformed with empty vector plants by inducing higher antioxidant enzyme activities, decreasing cell membrane damage, increasing abscisic acid (ABA) content, causing reinforced drought resistance related gene expression profiles. The 3,3'-diaminobenzidine (DAB) and nitroblue tetrazolium (NBT) staining results also showed less relative oxygen species (ROS) content in KdN41-overexpressing tobacco leaf during drought stress. Surprisingly, by re-watering after drought stress, KdN41-overexpressing tobacco showed earlier flowering. Overall, the KdN41 gene plays roles in ROS scavenging and osmotic damage reduction to improve tobacco drought resistance, which may increase our understanding of the molecular network involved in developmental manipulation under drought stress in K. daigremontiana.

  20. Prioritizing stream types according to their potential risk to receive crop plant material--A GIS-based procedure to assist in the risk assessment of genetically modified crops and systemic insecticide residues.

    Science.gov (United States)

    Bundschuh, Rebecca; Kuhn, Ulrike; Bundschuh, Mirco; Naegele, Caroline; Elsaesser, David; Schlechtriemen, Ulrich; Oehen, Bernadette; Hilbeck, Angelika; Otto, Mathias; Schulz, Ralf; Hofmann, Frieder

    2016-03-15

    Crop plant residues may enter aquatic ecosystems via wind deposition or surface runoff. In the case of genetically modified crops or crops treated with systemic pesticides, these materials may contain insecticidal Bt toxins or pesticides that potentially affect aquatic life. However, the particular exposure pattern of aquatic ecosystems (i.e., via plant material) is not properly reflected in current risk assessment schemes, which primarily focus on waterborne toxicity and not on plant material as the route of uptake. To assist in risk assessment, the present study proposes a prioritization procedure of stream types based on the freshwater network and crop-specific cultivation data using maize in Germany as a model system. To identify stream types with a high probability of receiving crop materials, we developed a formalized, criteria-based and thus transparent procedure that considers the exposure-related parameters, ecological status--an estimate of the diversity and potential vulnerability of local communities towards anthropogenic stress--and availability of uncontaminated reference sections. By applying the procedure to maize, ten stream types out of 38 are expected to be the most relevant if the ecological effects from plant-incorporated pesticides need to be evaluated. This information is an important first step to identifying habitats within these stream types with a high probability of receiving crop plant material at a more local scale, including accumulation areas. Moreover, the prioritization procedure developed in the present study may support the selection of aquatic species for ecotoxicological testing based on their probability of occurrence in stream types having a higher chance of exposure. Finally, this procedure can be adapted to any geographical region or crop of interest and is, therefore, a valuable tool for a site-specific risk assessment of crop plants carrying systemic pesticides or novel proteins, such as insecticidal Bt toxins, expressed

  1. Transpiration and stomatal resistance variations of perennial tropical crops under soil water availability conditions and water deficit

    Directory of Open Access Journals (Sweden)

    José Ozinaldo Alves de Sena

    2007-03-01

    Full Text Available During the dry and rainy seasons, determinations of stomatal resistance and transpiration of five tropical crops were carried out: guarana (Paullinia cupana Kunth, coffee (Coffea arabica L., cashew (Anacardium occidentale L., guava (Psidium guajava L. and rubber (Hevea brasiliensis Muell. - Arg. trees. Experimental design was done at randomized complete blocks with five replications. During the dry season there was a decrease in values of stomatal resistance in the following order: guarana > coffee> cashew> guava > rubber, with values from 2.5 to 30.0 s.cm-1. During the rainy season the stomatal resistance values varied from 1.5 to 3.0 s.cm-1. The guarana and coffee crops showed higher resistance to water transpiration when compared to other crops. During the rainy season, the rubber tree continued to present lower stomatal resistance and, consequently, higher transpiration.O experimento foi realizado no Departamento de Produção Vegetal da Escola Superior de Agricultura "Luiz de Queiroz", ESALQ/USP, Piracicaba, São Paulo, Brasil, utilizando-se as culturas de guaranazeiro (Paullinia cupana Kunth, cafeeiro (Coffea arabica L., cajueiro (Anacardium occidentale L., goiabeira (Psidium guajava L. e seringueira (Hevea brasiliensis Muell. - Arg.. No período de seca (setembro/94 e de chuvas (novembro/94, realizaram-se determinações de resistência estomática (RE (s cm-1 e transpiração (T (µg cm-1 s-1 nas diferentes espécies. O delineamento experimental foi em blocos casualizados com cinco repetições. A partir das análises dos dados pode-se concluir: 1. diferenças significativas entre espécies, em termos das variáveis avaliadas no período de deficiência hídrica, com valores decrescentes de resistência estomática e crescente de transpiração na seguinte ordem: guaranazeiro > cafeeiro > cajueiro > goiabeira > seringueira; 2. Nas águas as diferenças entre espécies, para ambas as variáveis, foram menos evidentes, continuando a

  2. Changes in bird community composition in response to growth changes in short-rotation woody crop planting

    International Nuclear Information System (INIS)

    Tolbert, V.R.; Hanowski, J.; Schiller, A.; Hoffman, W.; Christian, D.; Lindberg, J.

    1997-01-01

    Hybrid poplar established as intensively managed short-rotation woody crops (SRWC) on former agricultural lands can provide habitat for wildlife. Studies of bird use of SRWC for nesting and during fall migration have shown that the numbers and kinds of breeding birds using mature plantings of hybrid poplar are similar to natural forested lands. In Minnesota, the number of species of breeding birds using habitat provided by clonal-trial plantings and young larger-scale plantings (12-64 ha) of hybrid poplar were initially most similar to those using grasslands and row-crops. As the plantings approached canopy closure, successional species became predominant. In the Pacific Northwest, breeding bird composition and density were very similar for mature plantings and forested areas; however, fall migrants were found primarily in forested areas. In the Southeast, preliminary comparisons of breeding bird use of plantings of sweetgum and sycamore with naturally regenerating forests of different ages and sizes and vegetation structure are showing no size effect on use. As with hybrid poplar, species use of the more mature plantings of sweetgum and sycamore was most similar to that of natural forests. (author)

  3. Rare earth elements (REEs): effects on germination and growth of selected crop and native plant species.

    Science.gov (United States)

    Thomas, Philippe J; Carpenter, David; Boutin, Céline; Allison, Jane E

    2014-02-01

    The phytotoxicity of rare earth elements (REEs) is still poorly understood. The exposure-response relationships of three native Canadian plant species (common milkweed, Asclepias syriaca L., showy ticktrefoil, Desmodium canadense (L.) DC. and switchgrass, Panicum virgatum L.) and two commonly used crop species (radish, Raphanus sativus L., and tomato, Solanum lycopersicum L.) to the REEs lanthanum (La), yttrium (Y) and cerium (Ce) were tested. In separate experiments, seven to eight doses of each element were added to the soil prior to sowing seeds. Effects of REE dose on germination were established through measures of total percent germination and speed of germination; effects on growth were established through determination of above ground biomass. Ce was also tested at two pH levels and plant tissue analysis was conducted on pooled samples. Effects on germination were mostly observed with Ce at low pH. However, effects on growth were more pronounced, with detectable inhibition concentrations causing 10% and 25% reductions in biomass for the two native forb species (A. syriaca and D. canadense) with all REEs and on all species tested with Ce in both soil pH treatments. Concentration of Ce in aboveground biomass was lower than root Ce content, and followed the dose-response trend. From values measured in natural soils around the world, our results continue to support the notion that REEs are of limited toxicity and not considered extremely hazardous to the environment. However, in areas where REE contamination is likely, the slow accumulation of these elements in the environment could become problematic. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. The Importance of the Microbial N Cycle in Soil for Crop Plant Nutrition.

    Science.gov (United States)

    Hirsch, Penny R; Mauchline, Tim H

    2015-01-01

    Nitrogen is crucial for living cells, and prior to the introduction of mineral N fertilizer, fixation of atmospheric N2 by diverse prokaryotes was the primary source of N in all ecosystems. Microorganisms drive the N cycle starting with N2 fixation to ammonia, through nitrification in which ammonia is oxidized to nitrate and denitrification where nitrate is reduced to N2 to complete the cycle, or partially reduced to generate the greenhouse gas nitrous oxide. Traditionally, agriculture has relied on rotations that exploited N fixed by symbiotic rhizobia in leguminous plants, and recycled wastes and manures that microbial activity mineralized to release ammonia or nitrate. Mineral N fertilizer provided by the Haber-Bosch process has become essential for modern agriculture to increase crop yields and replace N removed from the system at harvest. However, with the increasing global population and problems caused by unintended N wastage and pollution, more sustainable ways of managing the N cycle in soil and utilizing biological N2 fixation have become imperative. This review describes the biological N cycle and details the steps and organisms involved. The effects of various agricultural practices that exploit fixation, retard nitrification, and reduce denitrification are presented, together with strategies that minimize inorganic fertilizer applications and curtail losses. The development and implementation of new technologies together with rediscovering traditional practices are discussed to speculate how the grand challenge of feeding the world sustainably can be met. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Accelerated Generation of Selfed Pure Line Plants for Gene Identification and Crop Breeding

    Directory of Open Access Journals (Sweden)

    Guijun Yan

    2017-10-01

    Full Text Available Production of pure lines is an important step in biological studies and breeding of many crop plants. The major types of pure lines for biological studies and breeding include doubled haploid (DH lines, recombinant inbred lines (RILs, and near isogenic lines (NILs. DH lines can be produced through microspore and megaspore culture followed by chromosome doubling while RILs and NILs can be produced through introgressions or repeated selfing of hybrids. DH approach was developed as a quicker method than conventional method to produce pure lines. However, its drawbacks of genotype-dependency and only a single chance of recombination limited its wider application. A recently developed fast generation cycling system (FGCS achieved similar times to those of DH for the production of selfed pure lines but is more versatile as it is much less genotype-dependent than DH technology and does not restrict recombination to a single event. The advantages and disadvantages of the technologies and their produced pure line populations for different purposes of biological research and breeding are discussed. The development of a concept of complete in vitro meiosis and mitosis system is also proposed. This could integrate with the recently developed technologies of single cell genomic sequencing and genome wide selection, leading to a complete laboratory based pre-breeding scheme.

  6. Estimating water and nitrate leaching in tree crops using inverse modelled plant and soil hydraulic properties

    Science.gov (United States)

    Couvreur, Valentin; Kandelous, Maziar; Mairesse, Harmony; Baram, Shahar; Moradi, Ahmad; Pope, Katrin; Hopmans, Jan

    2015-04-01

    Groundwater quality is specifically vulnerable in irrigated agricultural lands in California and many other (semi-)arid regions of the world. The routine application of nitrogen fertilizers with irrigation water in California is likely responsible for the high nitrate concentrations in groundwater, underlying much of its main agricultural areas. To optimize irrigation/fertigation practices, it is essential that irrigation and fertilizers are applied at the optimal concentration, place, and time to ensure maximum root uptake and minimize leaching losses to the groundwater. The applied irrigation water and dissolved fertilizer, root nitrate and water uptake interact with soil and root properties in a complex manner that cannot easily be resolved. It is therefore that coupled experimental-modelling studies are required to allow for unravelling of the relevant complexities that result from typical variations of crop properties, soil texture and layering across farmer-managed fields. A combined field monitoring and modelling approach was developed to quantify from simple measurements the leaching of water and nitrate below the root zone. The monitored state variables are soil water content within the root zone, soil matric potential below the root zone, and nitrate concentration in the soil solution. Plant and soil properties of incremented complexity are optimized with the software HYDRUS in an inverse modelling scheme, which allows estimating leaching under constraint of hydraulic principles. Questions of optimal irrigation and fertilization timing can then be addressed using predictive results and global optimization algorithms.

  7. Phenalenone-type phytoalexins mediate resistance of banana plants (Musa spp.) to the burrowing nematode Radopholus similis.

    Science.gov (United States)

    Hölscher, Dirk; Dhakshinamoorthy, Suganthagunthalam; Alexandrov, Theodore; Becker, Michael; Bretschneider, Tom; Buerkert, Andreas; Crecelius, Anna C; De Waele, Dirk; Elsen, Annemie; Heckel, David G; Heklau, Heike; Hertweck, Christian; Kai, Marco; Knop, Katrin; Krafft, Christoph; Maddula, Ravi K; Matthäus, Christian; Popp, Jürgen; Schneider, Bernd; Schubert, Ulrich S; Sikora, Richard A; Svatoš, Aleš; Swennen, Rony L

    2014-01-07

    The global yield of bananas-one of the most important food crops-is severely hampered by parasites, such as nematodes, which cause yield losses up to 75%. Plant-nematode interactions of two banana cultivars differing in susceptibility to Radopholus similis were investigated by combining the conventional and spatially resolved analytical techniques (1)H NMR spectroscopy, matrix-free UV-laser desorption/ionization mass spectrometric imaging, and Raman microspectroscopy. This innovative combination of analytical techniques was applied to isolate, identify, and locate the banana-specific type of phytoalexins, phenylphenalenones, in the R. similis-caused lesions of the plants. The striking antinematode activity of the phenylphenalenone anigorufone, its ingestion by the nematode, and its subsequent localization in lipid droplets within the nematode is reported. The importance of varying local concentrations of these specialized metabolites in infected plant tissues, their involvement in the plant's defense system, and derived strategies for improving banana resistance are highlighted.

  8. Antimicrobial Peptide Resistance Genes in the Plant Pathogen Dickeya dadantii.

    Science.gov (United States)

    Pandin, Caroline; Caroff, Martine; Condemine, Guy

    2016-11-01

    Modification of teichoic acid through the incorporation of d-alanine confers resistance in Gram-positive bacteria to antimicrobial peptides (AMPs). This process involves the products of the dltXABCD genes. These genes are widespread in Gram-positive bacteria, and they are also found in a few Gram-negative bacteria. Notably, these genes are present in all soft-rot enterobacteria (Pectobacterium and Dickeya) whose dltDXBAC operons have been sequenced. We studied the function and regulation of these genes in Dickeya dadantii dltB expression was induced in the presence of the AMP polymyxin. It was not regulated by PhoP, which controls the expression of some genes involved in AMP resistance, but was regulated by ArcA, which has been identified as an activator of genes involved in AMP resistance. However, arcA was not the regulator responsible for polymyxin induction of these genes in this bacterium, which underlines the complexity of the mechanisms controlling AMP resistance in D. dadantii Two other genes involved in resistance to AMPs have also been characterized, phoS and phoH dltB, phoS, phoH, and arcA but not dltD mutants were more sensitive to polymyxin than the wild-type strain. Decreased fitness of the dltB, phoS, and phoH mutants in chicory leaves indicates that their products are important for resistance to plant AMPs. Gram-negative bacteria can modify their lipopolysaccharides (LPSs) to resist antimicrobial peptides (AMPs). Soft-rot enterobacteria (Dickeya and Pectobacterium spp.) possess homologues of the dlt genes in their genomes which, in Gram-positive bacteria, are involved in resistance to AMPs. In this study, we show that these genes confer resistance to AMPs, probably by modifying LPSs, and that they are required for the fitness of the bacteria during plant infection. Two other new genes involved in resistance were also analyzed. These results show that bacterial resistance to AMPs can occur in bacteria through many different mechanisms that need to be

  9. Plant tolerance to high temperature in a changing environment: scientific fundamentals and production of heat stress tolerant crops

    Directory of Open Access Journals (Sweden)

    Craita eBita

    2013-07-01

    Full Text Available Global warming is predicted to have a general negative effect on plant growth due to the negative effect of high temperatures on plant development. The increasing threat of climatological extremes, including very high temperatures might lead to catastrophic loss of crop productivity and result in wide spread famine. In this review we assess the impact of global climate change on the production of agricultural crop production. There is a differential effect of climate change both in terms of geographic location and the crops that have will be likely to show the most extreme reductions in yield as a result of warming in general and the expected fluctuations in temperature. High temperature stress has a wide range of effects on plants both in terms of physiology, biochemistry and gene regulation pathways. In this review we present the recent advances of research on all these level of investigation focusing on potential leads that may help to understand more fully the mechanisms that make plants tolerant or susceptible to heat stress. Finally we review possible mechanisms and methods which can lead to the generation of new varieties that will allow sustainable yield production in a world likely to be challenged both by increasing population, higher average temperatures and larger temperature fluctuations.

  10. Eggplant and related species are promising genetic resources to dissect the plant immune response to Pseudomonas syringae and Xanthomonas euvesicatoria and to identify new resistance determinants.

    Science.gov (United States)

    Clarke, Christopher R; Hayes, Byron W; Runde, Brendan J; Wicker, Emmanuel; Vinatzer, Boris A

    2014-10-01

    The apparent lack of durability of many resistance (R) genes highlights the need for the constant identification of new genetic sources of resistance for the breeding of new disease-resistant crop cultivars. To this end, we screened a collection of accessions of eggplant and close relatives for resistance against Pseudomonas syringae pv. tomato (Pto) and Xanthomonas euvesicatoria (Xeu), foliar plant pathogens of many solanaceous crops. Both pathogens caused substantial disease on most genotypes of eggplant and its relatives. Promisingly, however, some of the genotypes were fully or partially resistant to either of the pathogens, suggesting the presence of effective resistance determinants in these genotypes. Segregation of resistance to the growth of Xeu following infiltration in F2 progeny from a cross of a resistant and susceptible genotype suggests that resistance to Xeu is inherited as a multigenic trait. With regard to Pto, a mutant strain lacking all 28 functional type III secreted effectors, and a Pseudomonas fluorescens strain expressing a P. syringae type III secretion system (T3SS), both elicit a strong cell death response on most eggplant lines. Several genotypes thus appear to harbour a mechanism for the direct recognition of a component of the T3SS. Therefore, eggplant and its close relatives are promising resources to unravel novel aspects of plant immunity and to identify new candidate R genes that could be employed in other Solanaceae in which Xeu and Pto cause agriculturally relevant diseases. © 2014 BSPP AND JOHN WILEY & SONS LTD.

  11. Induced mutation and epigenetics modification in plants for crop improvement by targeting CRISPR/Cas9 technology.

    Science.gov (United States)

    Khan, Muhammad Hafeez Ullah; Khan, Shahid U; Muhammad, Ali; Hu, Limin; Yang, Yang; Fan, Chuchuan

    2018-06-01

    Clustered regularly interspaced palindromic repeats associated protein Cas9 (CRISPR-Cas9), originally an adaptive immunity system of prokaryotes, is revolutionizing genome editing technologies with minimal off-targets in the present era. The CRISPR/Cas9 is now highly emergent, advanced, and highly specific tool for genome engineering. The technology is widely used to animal and plant genomes to achieve desirable results. The present review will encompass how CRISPR-Cas9 is revealing its beneficial role in characterizing plant genetic functions, genomic rearrangement, how it advances the site-specific mutagenesis, and epigenetics modification in plants to improve the yield of field crops with minimal side-effects. The possible pitfalls of using and designing CRISPR-Cas9 for plant genome editing are also discussed for its more appropriate applications in plant biology. Therefore, CRISPR/Cas9 system has multiple benefits that mostly scientists select for genome editing in several biological systems. © 2017 Wiley Periodicals, Inc.

  12. Pesticide productivity, host-plant resistance and productivity in China

    OpenAIRE

    Widawsky, David; Rozelle, Scott; Jin, Songqing; Huang, Jikun

    1998-01-01

    Pesticides are used as the primary method of pest control in Asian rice production. Conditions in China have led to demand for high and increasing rice yields, resulting in intensive cultivation and adoption of fertilizer responsive varieties. The consequence has been widespread pest infestations. Many studies have estimated pesticide productivity, but few have estimated the productivity of alternative methods of pest control, namely host-plant resistance. None have estimated the substitutabi...

  13. Effects of silicon on plant resistance to environmental stresses: review

    Science.gov (United States)

    Balakhnina, T.; Borkowska, A.

    2013-03-01

    The role of exogenous silicon in enhancing plant resistance to various abiotic stressors: salinity, drought, metal toxicities and ultraviolet radiation are presented. The data on possible involvement of silicon in reducing the reactive oxygen species generation, intensity of lipid peroxidation, and in some cases, increasing the activity of enzymes of the reactive oxygen species detoxificators: superoxide dismutase, ascorbate peroxidase, glutathione reductase, guaiacol peroxidase and catalase are analyzed.

  14. Antibiotic-resistant soil bacteria in transgenic plant fields

    OpenAIRE

    Demaneche, S.; Sanguin, H.; Pote, J.; Navarro, Elisabeth; Bernillon, D.; Mavingui, P.; Wildi, W.; Vogel, T. M.; Simonet, P.

    2008-01-01

    Understanding the prevalence and polymorphism of antibiotic resistance genes in soil bacteria and their potential to be transferred horizontally is required to evaluate the likelihood and ecological (and possibly clinical) consequences of the transfer of these genes from transgenic plants to soil bacteria. In this study, we combined culture-dependent and -independent approaches to study the prevalence and diversity of bla genes in soil bacteria and the potential impact that a 10-successive-y...

  15. A transformation method for obtaining marker-free plants of a cross-pollinating and vegetatively propagated crop

    NARCIS (Netherlands)

    Vetten, de N.; Wolters, A.M.A.; Raemakers, K.; Meer, van der I.M.; Stege, ter R.; Heeres, E.; Heeres, P.; Visser, R.G.F.

    2003-01-01

    It is generally thought that transformation of plant cells using Agrobacterium tumefaciens occurs at a very low frequency. Therefore, selection marker genes are used to identify the rare plants that have taken up foreign DNA. Genes encoding antibiotic and herbicide resistance are widely used for

  16. 77 FR 41358 - Bayer CropScience LP; Availability of Petition, Plant Pest Risk Assessment, and Environmental...

    Science.gov (United States)

    2012-07-13

    ... genetically engineered for resistance to the herbicides glyphosate and isoxaflutole. The petition has been... indirectly injure, cause damage to, or cause disease in any plant or plant product: A protozoan, a nonhuman... not change the regulatory status of soybean event FG72 and it would continue to be a regulated article...

  17. Decreasing Fertilizer use by Optimizing Plant-microbe Interactions for Sustainable Supply of Nitrogen for Bioenergy Crops

    Science.gov (United States)

    Schicklberger, M. F.; Huang, J.; Felix, P.; Pettenato, A.; Chakraborty, R.

    2013-12-01

    Nitrogen (N) is an essential component of DNA and proteins and consequently a key element of life. N often is limited in plants, affecting plant growth and productivity. To alleviate this problem, tremendous amounts of N-fertilizer is used, which comes at a high economic price and heavy energy demand. In addition, N-fertilizer also significantly contributes to rising atmospheric greenhouse gas concentrations. Therefore, the addition of fertilizer to overcome N limitation is highly undesirable. To explore reduction in fertilizer use our research focuses on optimizing the interaction between plants and diazotrophic bacteria, which could provide adequate amounts of N to the host-plant. Therefore we investigated the diversity of microbes associated with Tobacco (Nicotiana tabacum) and Switchgrass (Panicum virgatum), considered as potential energy crop for bioenergy production. Several bacterial isolates with representatives from Alphaproteobacteria, Gammaproteobacteria, Actinobacteria, Bacteriodetes and Bacilli were obtained from the roots, leaves, rhizoplane and rhizosphere of these plants. Majority of these isolates grew best with simple sugars and small organic acids. As shown by PCR amplification of nifH, several of these isolates are potential N2-fixing bacteria. We investigated diazotrophs for their response to elevated temperature and salinity (two common climate change induced stresses found on marginal lands), their N2-fixing ability, and their response to root exudates (which drive microbial colonization of the plant). Together this understanding is necessary for the development of eco-friendly, economically sustainable energy crops by decreasing their dependency on fertilizer.

  18. Tissue specific expression of potent insecticidal, Allium sativum leaf agglutinin (ASAL) in important pulse crop, chickpea (Cicer arietinum L.) to resist the phloem feeding Aphis craccivora.

    Science.gov (United States)

    Chakraborti, Dipankar; Sarkar, Anindya; Mondal, Hossain Ali; Das, Sampa

    2009-08-01

    The phloem sap-sucking hemipteran insect, Aphis craccivora, commonly known as cowpea aphid, cause major yield loss of important food legume crop chickpea. Among different plant lectins Allium sativum leaf agglutinin (ASAL), a mannose binding lectin was found to be potent antifeedant for sap sucking insect A. craccivora. Present study describes expression of ASAL in chickpea through Agrobacterium-mediated transformation of "single cotyledon with half embryo" explant. ASAL was expressed under the control of CaMV35S promoter for constitutive expression and phloem specific rolC promoter for specifically targeting the toxin at feeding site, using pCAMBIA2301 vector containing plant selection marker nptII. Southern blot analysis demonstrated the integration and copy number of chimeric ASAL gene in chickpea and its inheritance in T(1) and T(2) progeny plants. Expression of ASAL in T(0) and T(1) plants was confirmed through northern and western blot analysis. The segregation pattern of ASAL transgene was observed in T(1) progenies, which followed the 3:1 Mendelian ratio. Enzyme linked immunosorbant assay (ELISA) determined the level of ASAL expression in different transgenic lines in the range of 0.08-0.38% of total soluble protein. The phloem tissue specific expression of ASAL gene driven by rolC promoter has been monitored by immunolocalization analysis of mature stem sections. Survival and fecundity of A. craccivora decreased to 11-26% and 22-42%, respectively when in planta bioassay conducted on T(1) plants compared to untransformed control plant which showed 85% survival. Thus, through unique approach of phloem specific expression of novel insecticidal lectin (ASAL), aphid resistance has been successfully achieved in chickpea.

  19. Effect of rooting depth, plant density and planting date on maize (Zea Mays L.) yield and water use efficiency in semi-arid Zimbabwe: Modelling with AquaCrop

    NARCIS (Netherlands)

    Nyakudya, I.W.; Stroosnijder, L.

    2014-01-01

    Under low and poorly distributed rainfall higher food production can be achieved by increasing crop water use efficiency (WUE) through optimum soil fertility management and selection of deep-rooting cultivars, appropriate plant density and planting dates. We explored AquaCrop's applicability in

  20. A rapid and efficient method to study the function of crop plant transporters in Arabidopsis

    Science.gov (United States)

    Iron (Fe) is an essential micronutrient for humans. Fe deficiency disease is wide-spread and has lead to extensive studies on the mechanisms of Fe uptake and storage, especially in staple food crops such as rice. However, studies of functionally related genes in rice and other crops are often time a...

  1. Simulating the partitioning of biomass and nitrogen between roots and shoot in crop and grass plants

    NARCIS (Netherlands)

    Yin, X.; Schapendonk, A.H.C.M.

    2004-01-01

    Quantification of the assimilate partitioning between roots and shoot has been one of the components that need improvement in crop growth models. In this study we derived two equations for root-shoot partitioning of biomass and nitrogen (N) that hold for crops grown under steady-state conditions.

  2. Plant/soil concentration ratios for paired field and garden crops, with emphasis on iodine and the role of soil adhesion

    International Nuclear Information System (INIS)

    Sheppard, S.C.; Long, J.M.; Sanipelli, B.

    2010-01-01

    In the effort to predict the risks associated with contaminated soils, considerable reliance is placed on plant/soil concentration ratio (CR) values measured at sites other than the contaminated site. This inevitably results in the need to extrapolate among the many soil and plant types. There are few studies that compare CR among plant types that encompass both field and garden crops. Here, CRs for 40 elements were measured for 25 crops from farm and garden sites chosen so the grain crops were in close proximity to the gardens. Special emphasis was placed on iodine (I) because data for this element are sparse. For many elements, there were consistent trends among CRs for the various crop types, with leafy crops > root crops ≥ fruit crops ∼ seed crops. Exceptions included CR values for As, K, Se and Zn which were highest in the seed crops. The correlation of CRs from one plant type to another was evident only when there was a wide range in soil concentrations. In comparing CRs between crop types, it became apparent that the relationships differed for the rare earth elements (REE), which also had very low CR values. The CRs for root and leafy crops of REE converged to a minimum value. This was attributed to soil adhesion, despite the samples being washed, and the average soil adhesion for root crops was 500 mg soil kg -1 dry plant and for leafy crops was 5 g kg -1 . Across elements, the log CR was negatively correlated with log Kd (the soil solid/liquid partition coefficient), as expected. Although, this correlation is expected, measures of correlation coefficients suitable for stochastic risk assessment are not frequently reported. The results suggest that r ∼ -0.7 would be appropriate for risk assessment. -- Research highlights: →There are few studies that compare CRs among plant types that encompass both field and garden crops. Here, CRs for 40 elements were measured for 25 crops from farm and garden sites chosen so the grain crops were in close proximity

  3. Induction of systemic resistance in plants by biochar, a soil-applied carbon sequestering agent.

    Science.gov (United States)

    Elad, Yigal; David, Dalia Rav; Harel, Yael Meller; Borenshtein, Menahem; Kalifa, Hananel Ben; Silber, Avner; Graber, Ellen R

    2010-09-01

    Biochar is the solid coproduct of biomass pyrolysis, a technique used for carbon-negative production of second-generation biofuels. The biochar can be applied as a soil amendment, where it permanently sequesters carbon from the atmosphere as well as improves soil tilth, nutrient retention, and crop productivity. In addition to its other benefits in soil, we found that soil-applied biochar induces systemic resistance to the foliar fungal pathogens Botrytis cinerea (gray mold) and Leveillula taurica (powdery mildew) on pepper and tomato and to the broad mite pest (Polyphagotarsonemus latus Banks) on pepper. Levels of 1 to 5% biochar in a soil and a coconut fiber-tuff potting medium were found to be significantly effective at suppressing both diseases in leaves of different ages. In long-term tests (105 days), pepper powdery mildew was significantly less severe in the biochar-treated plants than in the plants from the unamended controls although, during the final 25 days, the rate of disease development in the treatments and controls was similar. Possible biochar-related elicitors of systemic induced resistance are discussed.

  4. Safety of virus-resistant transgenic plants two decades after their introduction: lessons from realistic field risk assessment studies.

    Science.gov (United States)

    Fuchs, Marc; Gonsalves, Dennis

    2007-01-01

    Potential safety issues have been raised with the development and release of virus-resistant transgenic plants. This review focuses on safety assessment with a special emphasis on crops that have been commercialized or extensively tested in the field such as squash, papaya, plum, grape, and sugar beet. We discuss topics commonly perceived to be of concern to the environment and to human health--heteroencapsidation, recombination, synergism, gene flow, impact on nontarget organisms, and food safety in terms of allergenicity. The wealth of field observations and experimental data is critically evaluated to draw inferences on the most relevant issues. We also express inside views on the safety and benefits of virus-resistant transgenic plants, and recommend realistic risk assessment approaches to assist their timely deregulation and release.

  5. Genetic transformation of Ornithogalum via particle bombardment and generation of Pectobacterium carotovorum-resistant plants.

    Science.gov (United States)

    Lipsky, Alexander; Cohen, Avner; Ion, Aurel; Yedidia, Iris

    2014-11-01

    Bacterial soft rot caused by Pectobacterium carotovorum subsp. carotovorum (Pcc) is one of the most devastating diseases of Ornithogalum species. No effective control measures are currently available to use against this pathogen; thus, introduction of resistant genes via genetic transformation into this crop is a promising approach. Tachyplesin I, an antimicrobial peptide, has been shown to effectively control numerous pathogenic bacteria, including Pcc. In this study, liquid-grown cell clusters of Ornithogalum dubium and Ornithogalum thyrsoides were bombarded with a pCAMBIA2301 vector containing a celI leader sequence fused to a gene encoding tachyplesin I, a neomycin phosphotransferase (nptII) gene that served as a selectable marker and a β-glucuronidase (GUS) gene that served as a reporter. Selection was carried out in the dark in liquid medium containing 80mg/L kanamycin. Regeneration was executed in the light after 6-14 months depending on the cultivar. Hundreds of transgenic plantlets were produced and their identity was confirmed through GUS activity assays. PCR and RT-PCR were used to confirm the presence of the target, reporter and selection genes in the divergent lines of plantlets. The resistance of the O. dubium plants to Pcc was evaluated in vitro, following infection with a highly virulent isolate from calla lily. Although control plantlets were completely macerated within a week, 87 putative transgenic subclones displayed varying levels of disease resistance. During three growing seasons in the greenhouse, the transgenic O. dubium lines grew poorly, whereas the transgenic O. thyrsoides plants grew similarly to non-transgenic plants. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  6. Effects of Planting Dates, Irrigation Management and Cover Crops on Growth and Yield of Saffron (Crocus sativus L.

    Directory of Open Access Journals (Sweden)

    A Koocheki

    2017-01-01

    Full Text Available Introduction Saffron as a winter active plant with low water requirement is the most strategic medicinal plant in arid and semi-arid parts of Iran. This slow-growing plant has narrow leaves and no aerial stem, hence weeds can be overcome it. Moreover, because of its root and canopy structure an important part of different resources is not used by this low input crop. Therefore, the use of associated crops could be an effective way for increasing resources use efficiencies (Koocheki et al., 2016. Appropriate corm planting date is another important factor that affects saffron growth and yield. Results of some studies show that late spring is the best time for corm planting (Ghasemi-Rooshnavand, 2009; Koocheki et al., 2016. In addition, irrigation management has been evaluated in some studies, but irrigation immediately after corm planting has not been investigated previously. Therefore, the aim of this study was to investigate the effect of irrigation management, planting date and the use of some companion crops on flowering of saffron during two growth cycles. Materials and methods This experiment was carried out as a split-split plot experiment based on a Randomized Complete Block Design with three replications at Research Station, Ferdowsi University of Mashhad, Iran in 2009-2011. Experimental factors included: planting date of saffron as main factor (first of June, first of August and first of October, 2009, the irrigation management as sub factor (irrigation and no irrigation after each planting date and the companion crops as sub-sub factor [Persian clover (Trifolium resupinatum, Bitter vetch (Lathyrus sativus and control. Corm planting was done in 10×25 cm distances with 12 cm depth. In the second year irrigation was done again in the plots which were irrigated after planting in the first year at the same previous dates. Companion crops were sown after first flower picking (November, 2009, then their residue were returned to the soil in

  7. Crop quality control system: a tool to control the visual quality of pot plants

    NARCIS (Netherlands)

    Dijkshoorn-Dekker, M.W.C.

    2002-01-01

    Key words: quality, growth, model, leaf unfolding rate, internode, plant height, plant width, leaf area, temperature, plant spacing, season, light, development, image processing, grading, neural network, pot plant, Ficus benjamina

  8. Determination of Soil and Plant Water Balance and Its Critical Stages for Rainfed Wheat Using Crop Water Stress Index (CWSI)

    OpenAIRE

    V. Feiziasl; A. Fotovat; A. Astaraei; A. Lakzian; M.A. Mousavi Shalmani

    2014-01-01

    In order to determination of water stress threshold and dryland wheat genotypes water status in different nitrogen managements, this experiment was carried out in split split plot RCBD design in three replications in 2010-2011 cropping year. Treatments included: N application time (whole fertilization of N at planting time , and its split fertilization as 2/3 at planting time and 1/3 in early spring), N rates (0, 30, 60 and 90 kg ha-1) and 7 wheat genotypes. Also these genotypes were grown in...

  9. Antibiotic-resistant bacteria in the guts of insects feeding on plants: prospects for discovering plant-derived antibiotics

    OpenAIRE

    Ignasiak, Katarzyna; Maxwell, Anthony

    2017-01-01

    Background Although plants produce many secondary metabolites, currently none of these are commercial antibiotics. Insects feeding on specific plants can harbour bacterial strains resistant to known antibiotics suggesting that compounds in the plant have stimulated resistance development. We sought to determine whether the occurrence of antibiotic-resistant bacteria in insect guts was a widespread phenomenon, and whether this could be used as a part of a strategy to identify antibacterial com...

  10. Ectopic expression of a novel OsExtensin-like gene consistently enhances plant lodging resistance by regulating cell elongation and cell wall thickening in rice.

    Science.gov (United States)

    Fan, Chunfen; Li, Ying; Hu, Zhen; Hu, Huizhen; Wang, Guangya; Li, Ao; Wang, Youmei; Tu, Yuanyuan; Xia, Tao; Peng, Liangcai; Feng, Shengqiu

    2018-01-01

    Plant lodging resistance is an important integrative agronomic trait of grain yield and quality in crops. Although extensin proteins are tightly associated with plant cell growth and cell wall construction, little has yet been reported about their impacts on plant lodging resistance. In this study, we isolated a novel extensin-like (OsEXTL) gene in rice, and selected transgenic rice plants that expressed OsEXTL under driven with two distinct promoters. Despite different OsEXTL expression levels, two-promoter-driven OsEXTL-transgenic plants, compared to a rice cultivar and an empty vector, exhibited significantly reduced cell elongation in stem internodes, leading to relatively shorter plant heights by 7%-10%. Meanwhile, the OsEXTL-transgenic plants showed remarkably thickened secondary cell walls with higher cellulose levels in the mature plants, resulting in significantly increased detectable mechanical strength (extension and pushing forces) in the mature transgenic plants. Due to reduced plant height and increased plant mechanical strength, the OsEXTL-transgenic plants were detected with largely enhanced lodging resistances in 3 years field experiments, compared to those of the rice cultivar ZH11. In addition, despite relatively short plant heights, the OsEXTL-transgenic plants maintain normal grain yields and biomass production, owing to their increased cellulose levels and thickened cell walls. Hence, this study demonstrates a largely improved lodging resistance in the OsEXTL-transgenic rice plants, and provides insights into novel extensin functions in plant cell growth and development, cell wall network construction and wall structural remodelling. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  11. Assessing quantitative resistance against Leptosphaeria maculans (phoma stem canker in Brassica napus (oilseed rape in young plants.

    Directory of Open Access Journals (Sweden)

    Yong-Ju Huang

    Full Text Available Quantitative resistance against Leptosphaeria maculans in Brassica napus is difficult to assess in young plants due to the long period of symptomless growth of the pathogen from the appearance of leaf lesions to the appearance of canker symptoms on the stem. By using doubled haploid (DH lines A30 (susceptible and C119 (with quantitative resistance, quantitative resistance against L. maculans was assessed in young plants in controlled environments at two stages: stage 1, growth of the pathogen along leaf veins/petioles towards the stem by leaf lamina inoculation; stage 2, growth in stem tissues to produce stem canker symptoms by leaf petiole inoculation. Two types of inoculum (ascospores; conidia and three assessment methods (extent of visible necrosis; symptomless pathogen growth visualised using the GFP reporter gene; amount of pathogen DNA quantified by PCR were used. In stage 1 assessments, significant differences were observed between lines A30 and C119 in area of leaf lesions, distance grown along veins/petioles assessed by visible necrosis or by viewing GFP and amount of L. maculans DNA in leaf petioles. In stage 2 assessments, significant differences were observed between lines A30 and C119 in severity of stem canker and amount of L. maculans DNA in stem tissues. GFP-labelled L. maculans spread more quickly from the stem cortex to the stem pith in A30 than in C119. Stem canker symptoms were produced more rapidly by using ascospore inoculum than by using conidial inoculum. These results suggest that quantitative resistance against L. maculans in B. napus can be assessed in young plants in controlled conditions. Development of methods to phenotype quantitative resistance against plant pathogens in young plants in controlled environments will help identification of stable quantitative resistance for control of crop diseases.

  12. Effect of planting date and crop density of autumn wheat (Triticum aestivum L. on density and biomass of weeds

    Directory of Open Access Journals (Sweden)

    R. Ghorbani

    2016-05-01

    Full Text Available Weeds in wheat (Triticum aestivum L. fields have always been a big problem in Iran and worldwide and must be managed by non-chemical especially cultural methods. A field experiment as factorial based on a randomized complete block design with four replications in a 1000 m2 field in Research Farm of Shirvan College of Agriculture was conducted during 2007-2008. Treatments included wheat densities of 400, 600 and 800 plants.m-2and planting dates of 1st of Nov., 20th of Nov., and 1st of Dec 2007. The results represented that the presence of Rapistrum rogusum, Phalaris spp., Descurainia sophia, Alopecurus myosurides and Hordeum murinum dominance. Delay in planting of wheat increased relative density of weeds. The lowest relative frequency of weeds was observed in planting date of 1st of November. Increase in crop density significantly decreased weed biomass, while it showed little effect on weed density trend. Effect of planting date was also significant on weed biomass. The highest weed biomass occurred in the planting date of Dec. the 1st. In conclusion, delay in planting of wheat create more chance and space for weed establishment, and therefore planting dense (600 plants.m-2 and early in season of wheat is recommended for lower weed damage.

  13. Soil precompression stress, penetration resistance and crop yields in relation to differently-trafficked, temperate-region sandy loam soils

    DEFF Research Database (Denmark)

    Schjønning, Per; Lamandé, Mathieu; Munkholm, Lars Juhl

    2016-01-01

    Compaction of the subsoil due to heavy traffic in moist and wet soil is widespread in modern agriculture. The objective of this study was to quantify the effects from realistic field traffic on soil penetration resistance and barley crop yield for three Luvisols developed from glacial till...... hypothesis of 3 Mg wheel load as an upper threshold for not inducing subsoil compaction was confirmed for the tractor-trailer treatments with repeated wheel passes but not supported for the single-pass machinery. The results call for further studies of the potential for carrying high loads using wide, low......-pressure tyres by crab steering/dog-walk machinery....

  14. The draft genome of whitefly Bemisia tabaci MEAM1, a global crop pest, provides novel insights into virus transmission, host adaptation, and insecticide resistance.

    Science.gov (United States)

    Chen, Wenbo; Hasegawa, Daniel K; Kaur, Navneet; Kliot, Adi; Pinheiro, Patricia Valle; Luan, Junbo; Stensmyr, Marcus C; Zheng, Yi; Liu, Wenli; Sun, Honghe; Xu, Yimin; Luo, Yuan; Kruse, Angela; Yang, Xiaowei; Kontsedalov, Svetlana; Lebedev, Galina; Fisher, Tonja W; Nelson, David R; Hunter, Wayne B; Brown, Judith K; Jander, Georg; Cilia, Michelle; Douglas, Angela E; Ghanim, Murad; Simmons, Alvin M; Wintermantel, William M; Ling, Kai-Shu; Fei, Zhangjun

    2016-12-14

    The whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) is among the 100 worst invasive species in the world. As one of the most important crop pests and virus vectors, B. tabaci causes substantial crop losses and poses a serious threat to global food security. We report the 615-Mb high-quality genome sequence of B. tabaci Middle East-Asia Minor 1 (MEAM1), the first genome sequence in the Aleyrodidae family, which contains 15,664 protein-coding genes. The B. tabaci genome is highly divergent from other sequenced hemipteran genomes, sharing no detectable synteny. A number of known detoxification gene families, including cytochrome P450s and UDP-glucuronosyltransferases, are significantly expanded in B. tabaci. Other expanded gene families, including cathepsins, large clusters of tandemly duplicated B. tabaci-specific genes, and phosphatidylethanolamine-binding proteins (PEBPs), were found to be associated with virus acquisition and transmission and/or insecticide resistance, likely contributing to the global invasiveness and efficient virus transmission capacity of B. tabaci. The presence of 142 horizontally transferred genes from bacteria or fungi in the B. tabaci genome, including genes encoding hopanoid/sterol synthesis and xenobiotic detoxification enzymes that are not present in other insects, offers novel insights into the unique biological adaptations of this insect such as polyphagy and insecticide resistance. Interestingly, two adjacent bacterial pantothenate biosynthesis genes, panB and panC, have been co-transferred into B. tabaci and fused into a single gene that has acquired introns during its evolution. The B. tabaci genome contains numerous genetic novelties, including expansions in gene families associated with insecticide resistance, detoxification and virus transmission, as well as numerous horizontally transferred genes from bacteria and fungi. We believe these novelties likely have shaped B. tabaci as a highly invasive polyphagous crop pest and

  15. Food plant derived disease tolerance and resistance in a natural butterfly-plant-parasite interactions.

    Science.gov (United States)

    Sternberg, Eleanore D; Lefèvre, Thierry; Li, James; de Castillejo, Carlos Lopez Fernandez; Li, Hui; Hunter, Mark D; de Roode, Jacobus C

    2012-11-01

    Organisms can protect themselves against parasite-induced fitness costs through resistance or tolerance. Resistance includes mechanisms that prevent infection or limit parasite growth while tolerance alleviates the fitness costs from parasitism without limiting infection. Although tolerance and resistance affect host-parasite coevolution in fundamentally different ways, tolerance has often been ignored in animal-parasite systems. Where it has been studied, tolerance has been assumed to be a genetic mechanism, unaffected by the host environment. Here we studied the effects of host ecology on tolerance and resistance to infection by rearing monarch butterflies on 12 different species of milkweed food plants and infecting them with a naturally occurring protozoan parasite. Our results show that monarch butterflies experience different levels of tolerance to parasitism depending on the species of milkweed that they feed on, with some species providing over twofold greater tolerance than other milkweed species. Resistance was also affected by milkweed species, but there was no relationship between milkweed-conferred resistance and tolerance. Chemical analysis suggests that infected monarchs obtain highest fitness when reared on milkweeds with an intermediate concentration, diversity, and polarity of toxic secondary plant chemicals known as cardenolides. Our results demonstrate that environmental factors-such as interacting species in ecological food webs-are important drivers of disease tolerance. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

  16. High level of resistance to aztreonam and ticarcillin in Pseudomonas aeruginosa isolated from soil of different crops in Brazil.

    Science.gov (United States)

    Pitondo-Silva, André; Martins, Vinicius Vicente; Fernandes, Ana Flavia Tonelli; Stehling, Eliana Guedes

    2014-03-01

    Pseudomonas aeruginosa can be found in water, soil, plants and, human and animal fecal samples. It is an important nosocomial pathogenic agent characterized by an intrinsic resistance to multiple antimicrobial agents and the ability to develop high-level (acquired) multidrug resistance through some mechanisms, among them, by the acquisition of plasmids and integrons, which are mobile genetic elements. In this study, 40 isolates from Brazilian soil were analyzed for antibiotic resistance, presence of integrons and plasmidial profile. The results demonstrated that the vast majority of the isolates have shown resistance for aztreonam (92.5%, n=37) and ticarcillin (85%, n=34), four isolates presented plasmids and eight isolates possess the class 1 integron. These results demonstrated that environmental isolates of P. aeruginosa possess surprising antibiotic resistance profile to aztreonam and ticarcillin, two antimicrobial agents for clinical treatment of cystic fibrosis patients and other infections occurred by P. aeruginosa. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. An Individual-Based Model of the Evolution of Pesticide Resistance in Heterogeneous Environments: Control of Meligethes aeneus Population in Oilseed Rape Crops

    Science.gov (United States)

    Stratonovitch, Pierre; Elias, Jan; Denholm, Ian; Slater, Russell; Semenov, Mikhail A.

    2014-01-01

    Preventing a pest population from damaging an agricultural crop and, at the same time, preventing the development of pesticide resistance is a major challenge in crop protection. Understanding how farming practices and environmental factors interact with pest characteristics to influence the spread of resistance is a difficult and complex task. It is extremely challenging to investigate such interactions experimentally at realistic spatial and temporal scales. Mathematical modelling and computer simulation have, therefore, been used to analyse resistance evolution and to evaluate potential resistance management tactics. Of the many modelling approaches available, individual-based modelling of a pest population offers most flexibility to include and analyse numerous factors and their interactions. Here, a pollen beetle (Meligethes aeneus) population was modelled as an aggregate of individual insects inhabiting a spatially heterogeneous landscape. The development of the pest and host crop (oilseed rape) was driven by climatic variables. The agricultural land of the landscape was managed by farmers applying a specific rotation and crop protection strategy. The evolution of a single resistance allele to the pyrethroid lambda cyhalothrin was analysed for different combinations of crop management practices and for a recessive, intermediate and dominant resistance allele. While the spread of a recessive resistance allele was severely constrained, intermediate or dominant resistance alleles showed a similar response to the management regime imposed. Calendar treatments applied irrespective of pest density accelerated the development of resistance compared to ones applied in response to prescribed pest density thresholds. A greater proportion of spring-sown oilseed rape was also found to increase the speed of resistance as it increased the period of insecticide exposure. Our study demonstrates the flexibility and power of an individual-based model to simulate how farming

  18. Captures of MFO-resistant Cydia pomonella adults as affected by lure, crop management system and flight.

    Science.gov (United States)

    Bosch, D; Rodríguez, M A; Avilla, J

    2016-02-01

    The main resistance mechanism of codling moth (Cydia pomonella) in the tree fruit area of Lleida (NE Spain) is multifunction oxidases (MFO). We studied the frequency of MFO-resistant adults captured by different lures, with and without pear ester, and flights in orchards under different crop management systems. The factor year affected codling moth MFO-resistance level, particularly in the untreated orchards, highlighting the great influence of codling moth migration on the spread of resistance in field populations. Chemical treatments and adult flight were also very important but mating disruption technique showed no influence. The second adult flight showed the highest frequency, followed by the first flight and the third flight. In untreated orchards, there were no significant differences in the frequency of MFO-resistant individuals attracted by Combo and BioLure. Red septa lures baited with pear ester (DA) captured sufficient insects only in the first generation of 2010, obtaining a significantly lower proportion of MFO-resistant adults than Combo and BioLure. In the chemically treated orchards, in 2009 BioLure caught a significantly lower proportion of MFO-resistant adults than Combo during the first and third flight, and also than DA during the first flight. No significant differences were found between the lures or flights in 2010. These results cannot support the idea of a higher attractiveness of the pear ester for MFO-resistant adults in the field but do suggest a high influence of the response to the attractant depending on the management of the orchard, particularly with regard to the use of chemical insecticides.

  19. Plant Glandular Trichomes as Targets for Breeding or Engineering of Resistance to Herbivores

    Science.gov (United States)

    Glas, Joris J.; Schimmel, Bernardus C. J.; Alba, Juan M.; Escobar-Bravo, Rocío; Schuurink, Robert C.; Kant, Merijn R.

    2012-01-01

    Glandular trichomes are specialized hairs found on the surface of about 30% of all vascular plants and are responsible for a significant portion of a plant’s secondary chemistry. Glandular trichomes are an important source of essential oils, i.e., natural fragrances or products that can be used by the pharmaceutical industry, although many of these substances have evolved to provide the plant with protection against herbivores and pathogens. The storage compartment of glandular trichomes usually is located on the tip of the hair and is part of the glandular cell, or cells, which are metabolically active. Trichomes and their exudates can be harvested relatively easily, and this has permitted a detailed study of their metabolites, as well as the genes and proteins responsible for them. This knowledge now assists classical breeding programs, as well as targeted genetic engineering, aimed to optimize trichome density and physiology to facilitate customization of essential oil production or to tune biocide activity to enhance crop protection. We will provide an overview of the metabolic diversity found within plant glandular trichomes, with the emphasis on those of the Solanaceae, and of the tools available to manipulate their activities for enhancing the plant’s resistance to pests. PMID:23235331

  20. [Effects of planting system on soil and water conservation and crop output value in a sloping land of Southwest China].

    Science.gov (United States)

    Xiang, Da-Bing; Yong, Tai-Wen; Yang, Wen-Yu; Yu, Xiao-Bo; Guo, Kai

    2010-06-01

    A three-year experiment was conducted to study the effects of wheat/maize/soybean with total no-tillage and mulching (NTM), wheat/maize/soybean with part no-tillage and part mulching (PTM), wheat/maize/soybean with total tillage without mulching (TWM), and wheat/maize/ sweet potato with total tillage without mulching (TWMS) on the soil and water conservation, soil fertility, and crop output value in a sloping land