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Sample records for aphid acrythociphon pisum

  1. Using the pea aphid Acrythociphon pisum as a tool for screening biological responses to chemicals and drugs

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    Ledger Terence

    2009-09-01

    Full Text Available Abstract Background Though the biological process of aphid feeding is well documented, no one to date has sought to apply it as a tool to screen the biological responses to chemicals and drugs, in ecotoxicology, genotoxicology and/or for interactions in the cascade of sequential molecular events of embryogenesis. Parthenogenetic insect species present the advantage of an anatomical system composed of multiple germarium/ovarioles in the same mother with all the intermediate maturation stages of embryos from oocyte to first instar larva birth. This could be used as an interesting model to visualize at which step drugs interact with the cell signalling pathway during the ordered developmental process. Findings We designed a simple test for screening drugs by investigating simultaneously zygote mitotic division, the progression of embryo development, cell differentiation at early developmental stages and finally organogenesis and population growth rate. We aimed to analyze the toxicology effects of compounds and/or their interference on cellular signalling by examining at which step of the cascade, from zygote to mature embryo, the developmental process is perturbed. We reasoned that a parthenogenetic founder insect, in which the ovarioles shelter numerous embryos at different developmental stages, would allow us to precisely pinpoint the step of embryogenesis in which chemicals act through specific molecular targets as the known ordered homeobox genes. Conclusion Using this method we report the results of a genotoxicological and demographic analysis of three compound models bearing in common a bromo group: one is integrated as a base analog in DNA synthesis, two others activate permanently kinases. We report that one compound (Br-du altered drastically embryogenesis, which argues in favor of this simple technique as a cheap first screening of chemicals or drugs to be used in a number of genotoxicology applications.

  2. Cannibalism in the pea aphid, Acyrthosiphon pisum.

    Science.gov (United States)

    Cooper, Lucy C; Desjonqueres, Camille; Leather, Simon R

    2014-12-01

    Previous observations of cannibalism have been made in the aphid Acyrthosiphon pisum (L.): this article seeks to quantify factors contributing to such behaviors. We observed and quantified the responses of a number of clones and life stages to varying levels of starvation, in the form of increasingly desiccated Vica faba L. plants (receiving 50, 25, or 10 mL every second day) or a complete absence of host plant. We found that, while the longest incidences of cannibalism are carried out by juveniles (F = 3.45, P = 0.019, df = 3) and targeted at adults, the starvation treatments had the most significant effect on the prevalence of cannibalism in mature A. pisum (F = 2.24, P = 0.025, df = 9). Furthermore, there was no difference between the prevalence or duration of cannibalistic activities within and between different clones (P ≥ 0.05 in all cases), though juveniles were more likely to target unrelated aphids (V = 6 112, P = 0.011), and spent more time feeding on aphids from the same culture (V = 6 062, P = 0.018).

  3. Genome sequence of the pea aphid Acyrthosiphon pisum

    DEFF Research Database (Denmark)

    Richards, S.; Gibbs, R. A.; Gerardo, N. M.;

    2010-01-01

    Aphids are important agricultural pests and also biological models for studies of insect-plant interactions, symbiosis, virus vectoring, and the developmental causes of extreme phenotypic plasticity. Here we present the 464 Mb draft genome assembly of the pea aphid Acyrthosiphon pisum. This first...... published whole genome sequence of a basal hemimetabolous insect provides an outgroup to the multiple published genomes of holometabolous insects. Pea aphids are host-plant specialists, they can reproduce both sexually and asexually, and they have coevolved with an obligate bacterial symbiont. Here we...... include genes involved in chromatin modification, miRNA synthesis, and sugar transport. Gene losses include genes central to the IMD immune pathway, selenoprotein utilization, purine salvage, and the entire urea cycle. The pea aphid genome reveals that only a limited number of genes have been acquired...

  4. Gene knockdown by RNAi in the pea aphid Acyrthosiphon pisum

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    Rispe Claude

    2007-09-01

    Full Text Available Abstract Background RNA interference (RNAi is a powerful method to inhibit gene expression in a sequence specific manner. Results Here, we described the development of RNAi by micro-injection of double-stranded RNA (dsRNA in the pea aphid Acyrthosiphon pisum. Injection of dsRNA into whole aphid body induced the silencing of two marker genes with different expression patterns: the ubiquitously expressed Ap-crt genes encoding a calreticulin and the gut specific Ap-cath-L gene encoding a cathepsin-L. Time-course analysis of the silencing showed similar temporal patterns for both genes: inhibition started at 1 day after injection, reached its maximum at 5 days and stopped at 7 days. A comparable 40% decrease of gene expression was observed for Ap-crt and Ap-cath-L. Conclusion The pea aphid is the first Hemipteran insect for which genome sequence will be available soon. The gene knockdown technique developed in this study will be an essential post-genomic tool for further investigations in aphidology.

  5. Antifeedant Activity and High Mortality in the Pea Aphid Acyrthosiphon pisum (Hemiptera: Aphidae) Induced by Biostable Insect Kinin Analogs

    Science.gov (United States)

    2010-01-01

    modern insecticides, making a search for alternative strategies urgent [7]. Furthermore aphids are not sensitive to the toxins from the bacterium Bacillus ... thuringiensis (Bt) [43]. Interestingly, the 525Mb genome of A. pisum has recently been sequenced by the International Aphid Genomic Consortium...feeding for 3 days on treated diet. In addition, it should bementioned that aphids are not sensitive to the insecticidal toxins of Bt [43]. Thus, the

  6. A protein from the salivary glands of the pea aphid, Acyrthosiphon pisum, is essential in feeding on a host plant.

    Science.gov (United States)

    Mutti, Navdeep S; Louis, Joe; Pappan, Loretta K; Pappan, Kirk; Begum, Khurshida; Chen, Ming-Shun; Park, Yoonseong; Dittmer, Neal; Marshall, Jeremy; Reese, John C; Reeck, Gerald R

    2008-07-22

    In feeding, aphids inject saliva into plant tissues, gaining access to phloem sap and eliciting (and sometimes overcoming) plant responses. We are examining the involvement, in this aphid-plant interaction, of individual aphid proteins and enzymes, as identified in a salivary gland cDNA library. Here, we focus on a salivary protein we have arbitrarily designated Protein C002. We have shown, by using RNAi-based transcript knockdown, that this protein is important in the survival of the pea aphid (Acyrthosiphon pisum) on fava bean, a host plant. Here, we further characterize the protein, its transcript, and its gene, and we study the feeding process of knockdown aphids. The encoded protein fails to match any protein outside of the family Aphididae. By using in situ hybridization and immunohistochemistry, the transcript and the protein were localized to a subset of secretory cells in principal salivary glands. Protein C002, whose sequence contains an N-terminal secretion signal, is injected into the host plant during aphid feeding. By using the electrical penetration graph method on c002-knockdown aphids, we find that the knockdown affects several aspects of foraging and feeding, with the result that the c002-knockdown aphids spend very little time in contact with phloem sap in sieve elements. Thus, we infer that Protein C002 is crucial in the feeding of the pea aphid on fava bean.

  7. Gene expression analysis of parthenogenetic embryonic development of the pea aphid, Acyrthosiphon pisum, suggests that aphid parthenogenesis evolved from meiotic oogenesis.

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    Dayalan G Srinivasan

    Full Text Available Aphids exhibit a form of phenotypic plasticity, called polyphenism, in which genetically identical females reproduce sexually during one part of the life cycle and asexually (via parthenogenesis during the remainder of the life cycle. The molecular basis for aphid parthenogenesis is unknown. Cytological observations of aphid parthenogenesis suggest that asexual oogenesis evolved either through a modification of meiosis or from a mitotic process. As a test of these alternatives, we assessed the expression levels and expression patterns of canonical meiotic recombination and germline genes in the sexual and asexual ovaries of the pea aphid, Acyrthosiphon pisum. We observed expression of all meiosis genes in similar patterns in asexual and sexual ovaries, with the exception that some genes encoding Argonaute-family members were not expressed in sexual ovaries. In addition, we observed that asexual aphid tissues accumulated unspliced transcripts of Spo11, whereas sexual aphid tissues accumulated primarily spliced transcripts. In situ hybridization revealed Spo11 transcript in sexual germ cells and undetectable levels of Spo11 transcript in asexual germ cells. We also found that an obligately asexual strain of pea aphid produced little spliced Spo11 transcript. Together, these results suggest that parthenogenetic oogenesis evolved from a meiosis-like, and not a mitosis-like, process and that the aphid reproductive polyphenism may involve a modification of Spo11 gene activity.

  8. Modification of Cry4Aa toward Improved Toxin Processing in the Gut of the Pea Aphid, Acyrthosiphon pisum.

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    Michael A Rausch

    Full Text Available Aphids are sap-sucking insects (order: Hemiptera that cause extensive damage to a wide range of agricultural crops. Our goal was to optimize a naturally occurring insecticidal crystalline (Cry toxins produced by the soil-dwelling bacterium Bacillus thuringiensis for use against the pea aphid, Acyrthosiphon pisum. On the basis that activation of the Cry4Aa toxin is a rate-limiting factor contributing to the relatively low aphicidal activity of this toxin, we introduced cathepsin L and cathepsin B cleavage sites into Cry4Aa for rapid activation in the aphid gut environment. Incubation of modified Cry4Aa and aphid proteases in vitro demonstrated enhanced processing of the toxin into the active form for some of the modified constructs relative to non-modified Cry4Aa. Aphids fed artificial diet with toxin at a final concentration of 125 μg/ml showed enhanced mortality after two days for one of the four modified constructs. Although only modest toxin improvement was achieved by use of this strategy, such specific toxin modifications designed to overcome factors that limit aphid toxicity could be applied toward managing aphid populations via transgenic plant resistance.

  9. Revisiting the anatomy of the central nervous system of a hemimetabolous model insect species: the pea aphid Acyrthosiphon pisum.

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    Kollmann, Martin; Minoli, Sebastian; Bonhomme, Joël; Homberg, Uwe; Schachtner, Joachim; Tagu, Denis; Anton, Sylvia

    2011-02-01

    Aphids show a marked phenotypic plasticity, producing asexual or sexual and winged or wingless morphs depending on environmental conditions and season. We describe here the general structure of the brain of various morphs of the pea aphid Acyrthosiphon pisum. This is the first detailed anatomical study of the central nervous system of an aphid by immunocytochemistry (synapsin, serotonin, and several neuropeptides), ethyl-gallate staining, confocal laser scanning microscopy, and three-dimensional reconstructions. The study has revealed well-developed optic lobes composed of lamina, medulla, and lobula complex. Ocelli are only present in males and winged parthenogenetic females. The central complex is well-defined, with a central body divided into two parts, a protocerebral bridge, and affiliated lateral accessory lobes. The mushroom bodies are ill-defined, lacking calyces, and only being visualized by using an antiserum against the neuropeptide orcokinin. The antennal lobes contain poorly delineated glomeruli but can be clearly visualized by performing antennal backfills. On the basis of our detailed description of the brain of winged and wingless parthenogenetic A. pisum females, an anatomical map is now available that should improve our knowledge of the way that these structures are involved in the regulation of phenotypic plasticity.

  10. Optimization of agroinfiltration in Pisum sativum provides a new tool for studying the salivary protein functions in the pea aphid complex

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    Endrick Guy

    2016-08-01

    Full Text Available Aphids are piercing-sucking insect pests and feed on phloem sap. During feeding, aphids inject a battery of salivary proteins into host plant. Some of these proteins function like effectors of microbial pathogens and influence the outcome of plant-aphid interactions. The pea aphid (Acyrthosiphon pisum is the model aphid and encompasses multiple biotypes each specialized to one or a few legume species, providing an opportunity to investigate the underlying mechanisms of the compatibility between plants and aphid biotypes. We aim to identify the aphid factors that determine the compatibility with host plants, hence involved in the host plant specialization process, and hypothesize that salivary proteins are one of those factors. Agrobacterium-mediated transient gene expression is a powerful tool to perform functional analyses of effector (salivary proteins in plants. However, the tool was not established for the legume species that A. pisum feeds on. Thus, we decided to optimize the method for legume plants to facilitate the functional analyses of A. pisum salivary proteins. We screened a range of cultivars of pea (Pisum sativum and alfalfa (Medicago sativa. None of the M. sativa cultivars was suitable for agroinfiltration under the tested conditions; however, we established a protocol for efficient transient gene expression in two cultivars of P. sativum, ZP1109 and ZP1130, using A. tumefaciens AGL-1 strain and the pEAQ-HT-DEST1 vector. We confirmed that the genes are expressed from three to ten days post-infiltration and that aphid lines of the pea adapted biotype fed and reproduced on these two cultivars while lines of alfalfa and clover biotypes did not. Thus, the pea biotype recognizes these two cultivars as typical pea plants. By using a combination of ZP1109 and an A. pisum line, we defined an agroinfiltration procedure to examine the effect of in planta expression of selected salivary proteins on A. pisum fitness and demonstrated that

  11. Bioinformatic prediction, deep sequencing of microRNAs and expression analysis during phenotypic plasticity in the pea aphid, Acyrthosiphon pisum

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    Leterme Nathalie

    2010-05-01

    Full Text Available Abstract Background Post-transcriptional regulation in eukaryotes can be operated through microRNA (miRNAs mediated gene silencing. MiRNAs are small (18-25 nucleotides non-coding RNAs that play crucial role in regulation of gene expression in eukaryotes. In insects, miRNAs have been shown to be involved in multiple mechanisms such as embryonic development, tissue differentiation, metamorphosis or circadian rhythm. Insect miRNAs have been identified in different species belonging to five orders: Coleoptera, Diptera, Hymenoptera, Lepidoptera and Orthoptera. Results We developed high throughput Solexa sequencing and bioinformatic analyses of the genome of the pea aphid Acyrthosiphon pisum in order to identify the first miRNAs from a hemipteran insect. By combining these methods we identified 149 miRNAs including 55 conserved and 94 new miRNAs. Moreover, we investigated the regulation of these miRNAs in different alternative morphs of the pea aphid by analysing the expression of miRNAs across the switch of reproduction mode. Pea aphid microRNA sequences have been posted to miRBase: http://microrna.sanger.ac.uk/sequences/ Conclusions Our study has identified candidates as putative regulators involved in reproductive polyphenism in aphids and opens new avenues for further functional analyses.

  12. Genetic Mapping of a Major Resistance Gene to Pea Aphid (Acyrthosipon pisum in the Model Legume Medicago truncatula

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    Lars G. Kamphuis

    2016-07-01

    Full Text Available Resistance to the Australian pea aphid (PA; Acyrthosiphon pisum biotype in cultivar Jester of the model legume Medicago truncatula is mediated by a single dominant gene and is phloem-mediated. The genetic map position for this resistance gene, APR (Acyrthosiphon pisum resistance, is provided and shows that APR maps 39 centiMorgans (cM distal of the A. kondoi resistance (AKR locus, which mediates resistance to a closely related species of the same genus bluegreen aphid (A. kondoi. The APR region on chromosome 3 is dense in classical nucleotide binding site leucine-rich repeats (NLRs and overlaps with the region harbouring the RAP1 gene which confers resistance to a European PA biotype in the accession Jemalong A17. Further screening of a core collection of M. truncatula accessions identified seven lines with strong resistance to PA. Allelism experiments showed that the single dominant resistance to PA in M. truncatula accessions SA10481 and SA1516 are allelic to SA10733, the donor of the APR locus in cultivar Jester. While it remains unclear whether there are multiple PA resistance genes in an R-gene cluster or the resistance loci identified in the other M. truncatula accessions are allelic to APR, the introgression of APR into current M. truncatula cultivars will provide more durable resistance to PA.

  13. Dickeya dadantii, a plant pathogenic bacterium producing Cyt-like entomotoxins, causes septicemia in the pea aphid Acyrthosiphon pisum.

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    Denis Costechareyre

    Full Text Available Dickeya dadantii (syn. Erwinia chrysanthemi is a plant pathogenic bacteria that harbours a cluster of four horizontally-transferred, insect-specific toxin genes. It was recently shown to be capable of causing an acute infection in the pea aphid Acyrthosiphon pisum (Insecta: Hemiptera. The infection route of the pathogen, and the role and in vivo expression pattern of these toxins, remain unknown. Using bacterial numeration and immunolocalization, we investigated the kinetics and the pattern of infection of this phytopathogenic bacterium within its insect host. We compared infection by the wild-type strain and by the Cyt toxin-deficient mutant. D. dadantii was found to form dense clusters in many luminal parts of the aphid intestinal tract, including the stomach, from which it invaded internal tissues as early as day 1 post-infection. Septicemia occurred soon after, with the fat body being the main infected tissue, together with numerous early infections of the embryonic chains showing embryonic gut and fat body as the target organs. Generalized septicemia led to insect death when the bacterial load reached about 10(8 cfu. Some individual aphids regularly escaped infection, indicating an effective partial immune response to this bacteria. Cyt-defective mutants killed insects more slowly but were capable of localisation in any type of tissue. Cyt toxin expression appeared to be restricted to the digestive tract where it probably assisted in crossing over the first cell barrier and, thus, accelerating bacterial diffusion into the aphid haemocel. Finally, the presence of bacteria on the surface of leaves hosting infected aphids indicated that the insects could be vectors of the bacteria.

  14. Post-reproductive parthenogenetic pea aphids (Acyrthosiphon pisum are visually identifiable and disproportionately positioned distally to clonal colonies

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    Erik T. Saberski

    2016-10-01

    Full Text Available The role of kin-selection in the evolution of post-reproductive life is controversial. While anthropological and demographic studies strongly suggest that humans and a few other species experience kin selection for significant post-reproductive survival, these results are necessarily correlational. Understanding could therefore be advanced by the development of a globally available, field and laboratory tractable experimental model of kin-selected post-reproductive survival. In only one invertebrate (Quadrartus yoshinomiyai, a gall-forming aphid endemic to Japan have individuals too old to reproduce been shown to be both numerous in natural habitats and able to help close relatives survive or reproduce. Pea aphids, (Acyrthosiphon pisum, common, tractable organisms, frequently outlive their reproductive ages in laboratories, live in tight interacting groups that are often clonal, and therefore should be evaluated as potential model organisms for the study of adaptive post-reproductive life. The first major step in this process is to identify an optimal method for assessing if a parthenogenetic adult is post-reproductive. We evaluated three methods, relying respectively on isolation in clip cages, visual examination for embryonic eyespots, and dissection. In every case each method identified the same individuals as reproductive versus post-reproductive. While the clip-cage method requires a multi-day wait to produce data, and dissection is inevitably fatal, the eyespot method is quick (under one minute per individual easy, and non-invasive. This method makes it possible to accurately assess the post-reproductive status of a large number of parthenogenetic pea aphids. We demonstrate the usefulness of the eyespot method in showing that while reproductively valuable adults tend to place themselves near the centers of clonal colonies, less valuable post-reproductive adults are more often at or beyond the edges of colonies. These encouraging early

  15. Post-reproductive parthenogenetic pea aphids (Acyrthosiphon pisum) are visually identifiable and disproportionately positioned distally to clonal colonies.

    Science.gov (United States)

    Saberski, Erik T; Diamond, Julia Daisy; Henneman, Nathaniel Fath; Levitis, Daniel A

    2016-01-01

    The role of kin-selection in the evolution of post-reproductive life is controversial. While anthropological and demographic studies strongly suggest that humans and a few other species experience kin selection for significant post-reproductive survival, these results are necessarily correlational. Understanding could therefore be advanced by the development of a globally available, field and laboratory tractable experimental model of kin-selected post-reproductive survival. In only one invertebrate (Quadrartus yoshinomiyai, a gall-forming aphid endemic to Japan) have individuals too old to reproduce been shown to be both numerous in natural habitats and able to help close relatives survive or reproduce. Pea aphids, (Acyrthosiphon pisum), common, tractable organisms, frequently outlive their reproductive ages in laboratories, live in tight interacting groups that are often clonal, and therefore should be evaluated as potential model organisms for the study of adaptive post-reproductive life. The first major step in this process is to identify an optimal method for assessing if a parthenogenetic adult is post-reproductive. We evaluated three methods, relying respectively on isolation in clip cages, visual examination for embryonic eyespots, and dissection. In every case each method identified the same individuals as reproductive versus post-reproductive. While the clip-cage method requires a multi-day wait to produce data, and dissection is inevitably fatal, the eyespot method is quick (under one minute per individual) easy, and non-invasive. This method makes it possible to accurately assess the post-reproductive status of a large number of parthenogenetic pea aphids. We demonstrate the usefulness of the eyespot method in showing that while reproductively valuable adults tend to place themselves near the centers of clonal colonies, less valuable post-reproductive adults are more often at or beyond the edges of colonies. These encouraging early results provide both

  16. Feeding-based RNA interference of a gap gene is lethal to the pea aphid, Acyrthosiphon pisum.

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    Jianjun Mao

    Full Text Available The gap gene hunchback (hb is a key regulator in the anteroposterior patterning of insects. Loss-of-function of hb resulted in segmentation defects in the next generation. In this paper, hb expression level was investigated at different developmental stages of the pea aphid, Acyrthosiphon pisum (Ap. Aphb mRNA was most early detected at the first instar stage and showed an incontinuous increase in the whole life cycle. Ingested RNA interference was performed at the second instar stage to knockdown the Aphb expression. Continuous feeding of Aphb double-stranded RNA mixed in artificial diet led to reduction of Aphb transcripts and rise of insect lethality. These results indicated that hunchback was a good RNAi target in the management of insect pests.

  17. Nicotinic Acetylcholine Receptor Gene Family of the Pea Aphid, Acyrthosiphon pisum

    Institute of Scientific and Technical Information of China (English)

    LIU Yi-peng; LIN Ke-jian; LIU Yang; GUI Fu-rong; WANG Gui-rong

    2013-01-01

    The nicotinic acetylcholine receptors (nAchRs) are cholinergic receptors that form ligand-gated ion channels by ifve subunits in insect and vertebrate nervous systems. The insect nAChR is the molecular target of a class of insecticides, neonicotinoids. Here, we identiifed and cloned 11 candidate nAChR subunit genes in Acyrthosiphon pisum using genome-based bioinformatics combined modern molecular techniques. Most A. pisum nAChRs including α1, α2, α3, α4, α6, α8, and β1 show highly sequence identities with the counterparts of other insects examined. Expression proifles analysis showed that all subunit genes were expressed in adult head. At least two subunits have alternative splicing that obviously increase A. pisum nicotinic receptor diversity. This study will be invaluable for exploring the molecular mechanisms of neonicotinoid-like insecticides in sucking pests, and for ultimately establishing the screening platform of novel insecticides.

  18. Taxonomy Icon Data: pea aphid [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available pea aphid Acyrthosiphon pisum Arthropoda Acyrthosiphon_pisum_L.png Acyrthosiphon_pisum_NL.png Acyrthosiph...on_pisum_S.png Acyrthosiphon_pisum_NS.png http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Acyrthosiph...on+pisum&t=L http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Acyrthosiphon+pisum&t=NL http:...//biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Acyrthosiphon+pisum&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Acyrthosiphon+pisum&t=NS ...

  19. Identification of distinct quantitative trait loci associated with defence against the closely related aphids Acyrthosiphon pisum and A. kondoi in Medicago truncatula

    KAUST Repository

    Guo, Su-Min

    2012-03-21

    Aphids are a major family of plant insect pests. Medicago truncatula and Acyrthosiphon pisum (pea aphid, PA) are model species with a suite of resources available to help dissect the mechanism underlying plant-aphid interactions. A previous study focused on monogenic and relatively strong resistance in M. truncatula to PA and other aphid species. In this study a moderate resistance to PA was characterized in detail in the M. truncatula line A17 and compared with the highly susceptible line A20 and the more resistant line Jester. The results show that PA resistance in A17 involves both antibiosis and tolerance, and that resistance is phloem based. Quantitative trait locus (QTL) analysis using a recombinant inbred line (RIL) population (n=114) from a cross between A17 and A20 revealed that one locus, which co-segregated with AIN (Acyrthosiphon-induced necrosis) on chromosome 3, is responsible for the reduction of aphid biomass (indicator of antibiosis) for both PA and bluegreen aphid (BGA, A. kondoi), albeit to a lesser degree for PA than BGA. Interestingly, two independent loci on chromosomes 5 and 3 were identified for the plant biomass reduction (indicator of plant tolerance) by PA and BGA, respectively, demonstrating that the plant\\'s tolerance response to these two closely related aphid species is distinct. Together with previously identified major resistant (R) genes, the QTLs identified in this study are powerful tools to understand fully the spectrum of plant defence against sap-sucking insects and provide opportunities for breeders to generate effective and sustainable strategies for aphid control. 2012 The Author.

  20. Life-history trade-offs mediate 'personality' variation in two colour morphs of the pea aphid, Acyrthosiphon pisum.

    Science.gov (United States)

    Schuett, Wiebke; Dall, Sasha R X; Kloesener, Michaela H; Baeumer, Jana; Beinlich, Felix; Eggers, Till

    2015-01-01

    Life-history trade-offs are considered a major driving force in the emergence of consistent behavioural differences (personality variation); but empirical tests are scarce. We investigated links between a personality trait (escape response), life-history and state variables (growth rate, size and age at first reproduction, age-dependent reproductive rates, lifetime reproductive success, life span) in red and green colour morphs of clonal pea aphids, Acyrthosiphon pisum. Escape response (dropping/non-dropping off a plant upon a predatory attack) was measured repeatedly to classify individuals as consistent droppers, consistent nondroppers or inconsistents. Red morphs experienced stronger trade-offs between early reproduction and life span than green morphs; and red consistent (non)droppers had highest lifetime reproductive success. Red droppers followed a risk-averse life-history strategy (high late reproduction), red nondroppers a risk-prone strategy (high early reproduction), while reproductive rates were equivalent for all green behavioural types and red inconsistents. This suggests that red morphs suffer the highest costs of dropping (they are most conspicuous to predators), which 'equivalates' fitness payoffs to both risk-takers (red non-droppers) and risk-averse red droppers. The strong trade-off also means that committing to a particular lifestyle (being consistent) maximises fitness. Our study suggests that life-history trade-offs likely mediate personality variation but effects might depend on interactions with other organismal characteristics (here: colour morph).

  1. Genomic evidence for complementary purine metabolism in the pea aphid, Acyrthosiphon pisum, and its symbiotic bacterium Buchnera aphidicola.

    Science.gov (United States)

    Ramsey, J S; MacDonald, S J; Jander, G; Nakabachi, A; Thomas, G H; Douglas, A E

    2010-03-01

    The purine salvage pathway recycles purines to nucleotides, promoting efficient utilization of purine nucleotides. Exceptionally among animals with completely sequenced genomes, the pea aphid lacks key purine recycling genes that code for purine nucleoside phosphorylase and adenosine deaminase, indicating that the aphid can neither metabolize nucleosides to the corresponding purines, nor adenosine to inosine. Purine metabolism genes in the symbiotic bacterium Buchnera complement aphid genes, and Buchnera can meet its nucleotide requirement from aphid-derived guanosine. Buchnera demand for nucleosides may have relaxed the selection for purine recycling in the aphid, leading to the loss of key aphid purine salvage genes. Further, the coupled purine metabolism of aphid and Buchnera could contribute to the dependence of the pea aphid on this symbiosis.

  2. DsRNA degradation in the pea aphid (Acyrthosiphon pisum) associated with lack of response in RNAi feeding and injection assay.

    Science.gov (United States)

    Christiaens, Olivier; Swevers, Luc; Smagghe, Guy

    2014-03-01

    Over the past decade, RNA interference (RNAi), the sequence-specific suppression of gene expression, has proven very promising for molecular research in many species, including model insects as Tribolium castaneum and Apis mellifera. It showed its usefulness to analyze gene function and its potential to manage pest populations and reduce disease pathogens. However, in several insects, the efficiency of RNAi is low or very variable at best. One of the factors that could influence RNAi efficiency in insects is degradation of dsRNA after administration to the insect. In this paper, we report on the importance of dsRNA breakdown in the pea aphid (Acyrthosiphon pisum) associated with the absence of an RNAi response upon oral feeding and injection with dsRNA targeting different genes such as the ecdysone hormone receptor and ultraspiracle. In essence, we discovered that both the salivary secretions of aphids and the hemolymph were able to degrade the dsRNA. In parallel, introduction of dsRNA in the aphid body was not able to provoke a response in the expression of the siRNA core machinery genes.

  3. Seasonal dynamics of: the pea aphid, Acyrthosiphon pisum (Harris, its natural enemies the seven spotted lady beetle Coccinella septempunctata Linnaeus and variegated lady beetle Hippodamia variegata Goeze, and their parasitoid Dinocampus coccinellae (Schrank

    Directory of Open Access Journals (Sweden)

    Soleimani Safura

    2015-12-01

    Full Text Available Two important lady beetle species commonly found in alfalfa fields in Iran are the variegated lady beetle Hippodamia variegata Goeze and the seven spotted lady beetle Coccinella septempunctata (Linnaeus, 1758 (Coleoptera: Coccinellidae. These two species attack many aphid species including the pea aphid, Acyrthosiphon pisum (Harris (Hemiptera: Aphididae. In this study, the seasonal population changes of A. pisum, H. variegata, C. septempunctata and the parasitoid, Dinocampus coccinellae (Schrank (Hymenoptera: Braconidae were studied in alfalfa fields in the 2012 and 2013 seasonal periods. The highest ladybird densities were noted on July 5, 2012 and on September 6, 2013 (17.2±2.8 and 13.4±1.6 individuals per 20 sweeps, respectively. Parasitism rates by D. coccinellae ranged from approximately 3 to 6% in two subsequent years, respectively. Parasitism was higher early in the growing season. Most parasitised ladybirds were females. There was no significant relationship between the temperature and relative humidity with pea aphid populations, although the aphid populations declined during the hot summer period. In contrast, the relationship between temperature and the H. variegata population was significant and positive in both years of the study. It has been shown that these lady beetle species have a major role in reducing the pea aphid populations in alfalfa fields. Due to the relatively low percentage of field parasitism by D. coccinellae, this parasite might not reduce the biocontrol efficiency of lady beetle species.

  4. Selection of reference genes for expression analysis using quantitative real-time PCR in the pea aphid, Acyrthosiphon pisum (Harris (Hemiptera, Aphidiae.

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    Chunxiao Yang

    Full Text Available To facilitate gene expression study and obtain accurate qRT-PCR analysis, normalization relative to stable expressed housekeeping genes is required. In this study, expression profiles of 11 candidate reference genes, including actin (Actin, elongation factor 1 α (EF1A, TATA-box-binding protein (TATA, ribosomal protein L12 (RPL12, β-tubulin (Tubulin, NADH dehydrogenase (NADH, vacuolar-type H+-ATPase (v-ATPase, succinate dehydrogenase B (SDHB, 28S ribosomal RNA (28S, 16S ribosomal RNA (16S, and 18S ribosomal RNA (18S from the pea aphid Acyrthosiphon pisum, under different developmental stages and temperature conditions, were investigated. A total of four analytical tools, geNorm, Normfinder, BestKeeper, and the ΔCt method, were used to evaluate the suitability of these genes as endogenous controls. According to RefFinder, a web-based software tool which integrates all four above-mentioned algorithms to compare and rank the reference genes, SDHB, 16S, and NADH were the three most stable house-keeping genes under different developmental stages and temperatures. This work is intended to establish a standardized qRT-PCR protocol in pea aphid and serves as a starting point for the genomics and functional genomics research in this emerging insect model.

  5. Multimodal dynamic response of the Buchnera aphidicola pLeu plasmid to variations in leucine demand of its host, the pea aphid Acyrthosiphon pisum.

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    Viñuelas, José; Febvay, Gérard; Duport, Gabrielle; Colella, Stefano; Fayard, Jean-Michel; Charles, Hubert; Rahbé, Yvan; Calevro, Federica

    2011-09-01

    Aphids, important agricultural pests, can grow and reproduce thanks to their intimate symbiosis with the γ-proteobacterium Buchnera aphidicola that furnishes them with essential amino acids lacking in their phloem sap diet. To study how B. aphidicola, with its reduced genome containing very few transcriptional regulators, responds to variations in the metabolic requirements of its host, we concentrated on the leucine metabolic pathway. We show that leucine is a limiting factor for aphid growth and it displays a stimulatory feeding effect. Our metabolic analyses demonstrate that symbiotic aphids are able to respond to leucine starvation or excess by modulating the neosynthesis of this amino acid. At a molecular level, this response involves an early important transcriptional regulation (after 12 h of treatment) followed by a moderate change in the pLeu plasmid copy number. Both responses are no longer apparent after 7 days of treatment. These experimental data are discussed in the light of a re-annotation of the pLeu plasmid regulatory elements. Taken together, our data show that the response of B. aphidicola to the leucine demand of its host is multimodal and dynamically regulated, providing new insights concerning the genetic regulation capabilities of this bacterium in relation to its symbiotic functions.

  6. Predators of the Alfalfa Aphids Acyrthosiphon pisum (Harris, Aphis craccivora Koch, and Therioaphis trifolii (Monell (Hemiptera: Aphidoidea as Determined by the Serological Technique

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    Suzan Cunha

    2016-08-01

    Resumo. A serologia é uma técnica imunológica baseada em reações antígeno/anticorpo, em que suas principais vantagens são a alta sensibilidade e especificidade que permitem o reconhecimento biológico em nível molecular. Este trabalho avalia o uso da técnica serológica para determinar os predadores dos pulgões da alfafa, Acyrthosiphon pisum (Harris, Aphis craccivora Koch e Therioaphis trifolii (Monell (Hemiptera: Aphidoidea. As coletas dos pulgões para a obtenção dos anticorpos e de seus possíveis predadores para serem utilizados como antígenos foram realizadas nos campos de alfafa da Unidade da Embrapa Pecuária Sudeste, São Carlos, SP. no período de agosto de 2011 a julho de 2012. Foram testados 2.161 artrópodes predadores, incluindo insetos e aranhas. Os anticorpos obtidos para os pulgões A. craccivora, A. pisum, e T. trifolii mostraram identidade parcial mas, ainda assim, permitiu reconhecer os predadores dos pulgões da alfafa. Dentre os insetos, sirfídeos e crisopídeos foram os que apresentaram as maiores porcentagens de resultados positivos nos testes serológicos. A. craccivora foi o afídeo mais consumido pelos predadores.

  7. Tangible benefits of the pea aphid genome sequencing in proteomics research: enhancements in protein identification, data incorporation, and evaluation criteria

    Science.gov (United States)

    The pea aphid, Acyrthosiphon pisum, is an important agricultural pest and a model system for numerous aspects of aphid biology, including sexual and asexual reproduction, bacterial endosymbiosis, insecticide resistance, and the evolution of aphid and plant host interactions. Recently, its complete ...

  8. Microorganism-associated semiochemicals reduce the size of aphid populations in potato fields

    OpenAIRE

    Alabi, Taofic; Brostaux, Yves; Grigorescu, Alina; Fischer, Christophe; Thonart, Philippe; Lognay, Georges; Haubruge, Eric; Francis, Frédéric; Verheggen, François

    2014-01-01

    The chemical cues released by many insect species, including agricultural pests, are used by predators and parasitoids to locate their prey or host. For instance, aphids excrete honeydew, which contains bacteria that produce semiochemicals. Ladybeetles and hoverflies use these semiochemicals to locate the colonies of prey aphid species. One bacterium (Staphylococcus sciuri) has been identified in the honeydew of the pea aphid, Acyrthosiphon pisum. This bacterium is responsible for the product...

  9. Aphid pheromones.

    Science.gov (United States)

    Dewhirst, Sarah Y; Pickett, John A; Hardie, Jim

    2010-01-01

    Aphids are the main insect pests of agricultural crops in temperate regions causing major economic losses. Although broad-spectrum insecticides are available for control, alternative and more targeted methods are needed due to insecticide resistance and increasing environmental pressures. An alternative control method for aphids is to exploit their pheromones, which have been extensively studied in recent years. For example, aphids release alarm pheromones in response to natural enemy attack and these could be used to deter aphids from the crops. Sex pheromones have also been identified which could be used to interfere males locating conspecific females (oviparae), as well as for manipulating natural enemies. Several hypotheses relating to how species integrity is maintained via the aphid sex pheromone have been proposed. The composition and behavioral activity of these pheromones, and how their use could be implemented in integrated pest management systems to control aphids, is discussed.

  10. Ants Learn Aphid Species as Mutualistic Partners: Is the Learning Behavior Species-Specific?

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    Hayashi, Masayuki; Nakamuta, Kiyoshi; Nomura, Masashi

    2015-12-01

    In ant-aphid associations, many aphid species provide ants with honeydew and are tended by ants, whereas others are never tended and are frequently preyed upon by ants. In these relationships, ants must have the ability to discriminate among aphid species, with mutualistic aphids being accepted as partners rather than prey. Although ants reportedly use cuticular hydrocarbons (CHCs) of aphids to differentiate between mutualistic and non-mutualistic species, it is unclear whether the ability to recognize mutualistic aphid species as partners is innate or involves learning. Therefore, we tested whether aphid recognition by ants depends on learning, and whether the learning behavior is species-specific. When workers of the ant Tetramorium tsushimae had previously tended the cowpea aphid, Aphis craccivora, they were less aggressive toward this species. In addition, ants also reduced their aggressiveness toward another mutualistic aphid species, Aphis fabae, after tending A. craccivora, whereas ants remained aggressive toward the non-mutualistic aphid, Acyrthosiphon pisum, regardless of whether or not they had previous experience in tending A. craccivora. When ants were offered glass dummies treated with CHCs of these aphid species, ants that had tended A. craccivora displayed reduced aggression toward CHCs of A. craccivora and A. fabae. Chemical analyses showed the similarity of the CHC profiles between A. craccivora and A. fabae but not with A. pisum. These results suggest that aphid recognition of ants involves learning, and that the learning behavior may not be species-specific because of the similarity of CHCs between different aphid species with which they form mutualisms.

  11. Stem nematode counteracts plant resistance of aphids in alfalfa, Medicago sativa.

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    Ramirez, Ricardo A; Spears, Lori R

    2014-10-01

    Plants are exploited by a diverse community of insect herbivores and phytopathogens that interact indirectly through plant-mediated interactions. Generally, plants are thought to respond to insects and pathogens through different defensive signaling pathways. As plants are selected for resistance to one phytophagous organism type (insect vs. pathogen) in managed systems, it is not clear how this selection may affect community interactions. This study examined the effect of nematode-resistant varieties on aphid (Acyrthosiphon pisum) suppression, and then determined how infection by the stem nematode, Ditylenchus dipsaci, mediated ecological effects on aphids and on plant defense proteins. Four alfalfa (Medicago sativa) varieties were selected with resistance to nematodes only (+,-), aphids only (-,+), nematodes and aphids (+,+), and susceptibility to nematodes and aphids (-,-). Field and greenhouse experiments were conducted to isolate the effect of nematode infection and aphid abundance on each variety. We found that varieties resistant to nematode, regardless of aphid resistance, had the lowest aphid counts, suggesting possible cross-resistance. Aphid abundance, however, increased when plants were exposed to nematodes. Resistant varieties were associated with elevated saponins but these compounds were not affected by insect or pathogen feeding. Concentrations of peroxidases and trypsin inhibitors, however, were increased in nematode resistant varieties when exposed to nematodes and aphids, respectively. The patterns of plant defense were variable, and a combination of resistance traits and changes in nutrient availability may drive positive interactions between nematodes and aphids aboveground.

  12. Aphid reproductive investment in response to mortality risks

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    Barribeau Seth M

    2010-08-01

    Full Text Available Abstract Background Aphids are striking in their prodigious reproductive capacity and reliance on microbial endosymbionts, which provision their hosts with necessary amino acids and provide protection against parasites and heat stress. Perhaps as a result of this bacterial dependence, aphids have limited immune function that may leave them vulnerable to bacterial pathogens. An alternative, non-immunological response that may be available to infected aphids is to increase reproduction, thereby ameliorating fitness loss from infection. Such a response would reduce the need to mount a potentially energetically costly immune response, and would parallel that of other hosts that alter life-history traits when there is a risk of infection. Here we examined whether pea aphids (Acyrthosiphon pisum respond to immunological challenges by increasing reproduction. As a comparison to the response to the internal cue of risk elicited by immunological challenge, we also exposed pea aphids to an external cue of risk - the aphid alarm pheromone (E-β-farnesene (EBF, which is released in the presence of predators. For each challenge, we also examined whether the presence of symbionts modified the host response, as maintaining host fitness in the face of challenge would benefit both the host and its dependent bacteria. Results We found that aphids stabbed abdominally with a sterile needle had reduced fecundity relative to control aphids but that aphids stabbed with a needle bearing heat-killed bacteria had reproduction intermediate, and statistically indistinguishable, to the aphids stabbed with a sterile needle and the controls. Aphids with different species of facultative symbiotic bacteria had different reproductive patterns overall, but symbionts in general did not alter aphid reproduction in response to bacterial exposure. However, in response to exposure to alarm pheromone, aphids with Hamiltonella defensa or Serratia symbiotica symbiotic infections

  13. Enemy-free space promotes maintenance of host races in an aphid species.

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    Vosteen, Ilka; Gershenzon, Jonathan; Kunert, Grit

    2016-07-01

    The enormous biodiversity of herbivorous insects may arise from ecological speciation via continuous host-plant switches. Whether such switches are successful depends on the trade-off between different selection pressures that act on herbivores. Decreased herbivore performance due to suboptimal nutrition might be compensated for by a reduced natural enemy pressure. As a consequence, an "enemy-free space" on a certain plant might facilitate host-plant switches and maintain biotypes. To test this hypothesis, we used the pea aphid (Acyrthosiphon pisum) complex, which consists of at least 11 genetically distinct host races that are native to specific legume host plants but can all develop on the universal host plant Vicia faba. Three A. pisum host races native to Trifolium pratense, Pisum sativum, and Medicago sativa were investigated in experiments on their respective host plants and on the universal host plant V. faba. We found that hoverflies preferred to oviposit on P. sativum and the universal host V. faba. Since feeding by hoverfly larvae suppressed aphid population growth on these host plants, the native hosts M. sativa and T. pratense provided enemy-free space for the respective A. pisum races. Mobile predators, such as ants and ladybird beetles, preferred Pisum race aphids on V. faba over P. sativum. Thus, all three of the native host plants studied supply enemy-free space for A. pisum compared to the universal host V. faba. Reducing encounters between aphid races on V. faba would reduce gene flow among them and could contribute to maintaining the host races.

  14. Anticipatory and reactive crouching of pea aphids in response to environmental perturbations.

    Science.gov (United States)

    Ben-Ari, Matan; Talal, Stav; Inbar, Moshe

    2014-10-01

    Animals use different strategies to deal with changing environmental conditions. While standing and feeding on their host plant, aphids (Hemiptera: Aphididae) may be exposed to detrimental environmental perturbations, such as strong winds. If aphids are forcibly blown off the plant and spend time on the ground, they will face additional dangers by both ground-dwelling predators and detrimental soil temperature. It is therefore adaptive for aphids to behave in a way that lowers the risk of being removed from the plant. We observed that pea aphids (Acyrthosiphon pisum (Harris)) display a specific crouched body posture, previously undescribed, which reduces their chance of being carried off from the plant by sudden winds. We exposed aphids in the laboratory to different cues indicative of a windy environment: wind, plant vibration, and visual stimuli. We found that aphids crouch in two situations: 1) reactively, when they are being pulled by a continuous gust of wind threatening to dislodge them. 2) Anticipatorily, when environmental cues, such as plant vibration or continuous movement near their host plant, may signify that sudden wind gusts are expected. Crouching aphids were less likely to be dislodged by a sudden air stream or plant vibration than were aphids that did not crouch. Crouching thus improves the aphids' chances of remaining on their host plant under unfavorable environmental conditions.

  15. Inheritance patterns of secondary symbionts during sexual reproduction of pea aphid biotypes.

    Science.gov (United States)

    Peccoud, Jean; Bonhomme, Joël; Mahéo, Frédérique; de la Huerta, Manon; Cosson, Olivier; Simon, Jean-Christophe

    2014-06-01

    Herbivorous insects frequently harbor bacterial symbionts that affect their ecology and evolution. Aphids host the obligatory endosymbiont Buchnera, which is required for reproduction, together with facultative symbionts whose frequencies vary across aphid populations. These maternally transmitted secondary symbionts have been particularly studied in the pea aphid, Acyrthosiphon pisum, which harbors at least 8 distinct bacterial species (not counting Buchnera) having environmentally dependent effects on host fitness. In particular, these symbiont species are associated with pea aphid populations feeding on specific plants. Although they are maternally inherited, these bacteria are occasionally transferred across insect lineages. One mechanism of such nonmaternal transfer is paternal transmission to the progeny during sexual reproduction. To date, transmission of secondary symbionts during sexual reproduction of aphids has been investigated in only a handful of aphid lineages and 3 symbiont species. To better characterize this process, we investigated inheritance patterns of 7 symbiont species during sexual reproduction of pea aphids through a crossing experiment involving 49 clones belonging to 9 host-specialized biotypes, and 117 crosses. Symbiont species in the progeny were detected with diagnostic qualitative PCR at the fundatrix stage hatching from eggs and in later parthenogenetic generations. We found no confirmed case of paternal transmission of symbionts to the progeny, and we observed that maternal transmission of a particular symbiont species (Serratia symbiotica) was quite inefficient. We discuss these observations in respect to the ecology of the pea aphid.

  16. The cellular immune response of the pea aphid to foreign intrusion and symbiotic challenge.

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    Antonin Schmitz

    Full Text Available Recent studies suggest that the pea aphid (Acyrthosiphon pisum has low immune defenses. However, its immune components are largely undescribed, and notably, extensive characterization of circulating cells has been missing. Here, we report characterization of five cell categories in hemolymph of adults of the LL01 pea aphid clone, devoid of secondary symbionts (SS: prohemocytes, plasmatocytes, granulocytes, spherulocytes and wax cells. Circulating lipid-filed wax cells are rare; they otherwise localize at the basis of the cornicles. Spherulocytes, that are likely sub-cuticular sessile cells, are involved in the coagulation process. Prohemocytes have features of precursor cells. Plasmatocytes and granulocytes, the only adherent cells, can form a layer in vivo around inserted foreign objects and phagocytize latex beads or Escherichia coli bacteria injected into aphid hemolymph. Using digital image analysis, we estimated that the hemolymph from one LL01 aphid contains about 600 adherent cells, 35% being granulocytes. Among aphid YR2 lines differing only in their SS content, similar results to LL01 were observed for YR2-Amp (without SS and YR2-Ss (with Serratia symbiotica, while YR2-Hd (with Hamiltonella defensa and YR2(Ri (with Regiella insecticola had strikingly lower adherent hemocyte numbers and granulocyte proportions. The effect of the presence of SS on A. pisum cellular immunity is thus symbiont-dependent. Interestingly, Buchnera aphidicola (the aphid primary symbiont and all SS, whether naturally present, released during hemolymph collection, or artificially injected, were internalized by adherent hemocytes. Inside hemocytes, SS were observed in phagocytic vesicles, most often in phagolysosomes. Our results thus raise the question whether aphid symbionts in hemolymph are taken up and destroyed by hemocytes, or actively promote their own internalization, for instance as a way of being transmitted to the next generation. Altogether, we

  17. Hoverfly preference for high honeydew amounts creates enemy-free space for aphids colonizing novel host plants.

    Science.gov (United States)

    Vosteen, Ilka; Gershenzon, Jonathan; Kunert, Grit

    2016-09-01

    The existence of an enemy-free space can play an important role in aphid host race formation processes, but little is known about the mechanisms that create an area of low predation pressure on particular host plants. In this paper, we identify a mechanism generating lower predation pressure that promotes the maintenance of the different host races of the pea aphid (Acyrthosiphon pisum) complex, a well-studied model for ecological speciation. The pea aphid consists of at least 15 genetically distinct host races which are native to specific host plants of the legume family, but can all develop on the universal host plant Vicia faba. Previous work showed that hoverfly (Episyrphus balteatus) oviposition preferences contribute to the enemy-free space that helps to maintain the different pea aphid host races, and that higher amounts of honeydew are more attractive to ovipositing hoverflies. Here we demonstrated that aphid honeydew is produced in large amounts when aphid reproduction rate was highest, and is an important oviposition cue for hoverflies under field conditions. However, on less suitable host plants, where honeydew production is reduced, pea aphids enjoy lower predation rates. A reduction in enemy pressure can mitigate the performance disadvantages of aphids colonizing a novel host and probably plays an important role in pea aphid host race formation.

  18. Pea aphid promotes amino acid metabolism both in Medicago truncatula and bacteriocytes to favor aphid population growth under elevated CO2.

    Science.gov (United States)

    Guo, Huijuan; Sun, Yucheng; Li, Yuefei; Tong, Bin; Harris, Marvin; Zhu-Salzman, Keyan; Ge, Feng

    2013-10-01

    Rising atmospheric CO(2) levels can dilute the nitrogen (N) resource in plant tissue, which is disadvantageous to many herbivorous insects. Aphids appear to be an exception that warrants further study. The effects of elevated CO(2) (750 ppm vs. 390 ppm) were evaluated on N assimilation and transamination by two Medicago truncatula genotypes, a N-fixing-deficient mutant (dnf1) and its wild-type control (Jemalong), with and without pea aphid (Acyrthosiphon pisum) infestation. Elevated CO(2) increased population abundance and feeding efficiency of aphids fed on Jemalong, but reduced those on dnf1. Without aphid infestation, elevated CO(2) increased photosynthetic rate, chlorophyll content, nodule number, biomass, and pod number for Jemalong, but only increased pod number and chlorophyll content for dnf1. Furthermore, aphid infested Jemalong plants had enhanced activities of N assimilation-related enzymes (glutamine synthetase, Glutamate synthase) and transamination-related enzymes (glutamate oxalate transaminase, glutamine phenylpyruvate transaminase), which presumably increased amino acid concentration in leaves and phloem sap under elevated CO(2). In contrast, aphid infested dnf1 plants had decreased activities of N assimilation-related enzymes and transmination-related enzymes and amino acid concentrations under elevated CO(2). Furthermore, elevated CO(2) up-regulated expression of genes relevant to amino acid metabolism in bacteriocytes of aphids associated with Jemalong, but down-regulated those associated with dnf1. Our results suggest that pea aphids actively elicit host responses that promote amino acid metabolism in both the host plant and in its bacteriocytes to favor the population growth of the aphid under elevated CO(2).

  19. Modulation of legume defense signaling pathways by native and non-native pea aphid clones

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    Carlos Sanchez-Arcos

    2016-12-01

    Full Text Available The pea aphid (Acyrthosiphon pisum is a complex of at least 15 genetically different host races that are native to specific legume plants, but can all develop on the universal host plant Vicia faba. Despite much research it is still unclear why pea aphid host races (biotypes are able to colonize their native hosts while other host races are not. All aphids penetrate the plant and salivate into plant cells when they test plant suitability. Thus plants might react differently to the various pea aphid host races. To find out whether legume species vary in their defense responses to different pea aphid host races, we measured the amounts of salicylic acid (SA, the jasmonic acid-isoleucine conjugate (JA-Ile, other jasmonate precursors and derivatives, and abscisic acid (ABA in four different species (Medicago sativa, Trifolium pratense, Pisum sativum, V. faba after infestation by native and non-native pea aphid clones of various host races. Additionally, we assessed the performance of the clones on the four plant species. On M. sativa and T. pratense, non-native clones that were barely able to survive or reproduce, triggered a strong SA and JA-Ile response, whereas infestation with native clones led to lower levels of both phytohormones. On P. sativum, non-native clones, which survived or reproduced to a certain extent, induced fluctuating SA and JA-Ile levels, whereas the native clone triggered only a weak SA and JA-Ile response. On the universal host V. faba all aphid clones triggered only low SA levels initially, but induced clone-specific patterns of SA and JA-Ile later on. The levels of the active JA-Ile conjugate and of the other JA-pathway metabolites measured showed in many cases similar patterns, suggesting that the reduction in JA signaling was due to an effect upstream of OPDA. ABA levels were downregulated in all aphid clone-plant combinations and were therefore probably not decisive factors for aphid-plant compatibility. Our results

  20. Elevated Carbon Dioxide Concentration Reduces Alarm Signaling in Aphids.

    Science.gov (United States)

    Boullis, Antoine; Fassotte, Bérénice; Sarles, Landry; Lognay, Georges; Heuskin, Stéphanie; Vanderplanck, Maryse; Bartram, Stefan; Haubruge, Eric; Francis, Frédéric; Verheggen, François J

    2017-02-01

    Insects often rely on olfaction to communicate with conspecifics. While the chemical language of insects has been deciphered in recent decades, few studies have assessed how changes in atmospheric greenhouse gas concentrations might impact pheromonal communication in insects. Here, we hypothesize that changes in the concentration of atmospheric carbon dioxide affect the whole dynamics of alarm signaling in aphids, including: (1) the production of the active compound (E)-β-farnesene (Eβf), (2) emission behavior when under attack, (3) perception by the olfactory apparatus, and (4) the escape response. We reared two strains of the pea aphid, Acyrthosiphon pisum, under ambient and elevated CO2 concentrations over several generations. We found that an increase in CO2 concentration reduced the production (i.e., individual content) and emission (released under predation events) of Eβf. While no difference in Eβf neuronal perception was observed, we found that an increase in CO2 strongly reduced the escape behavior expressed by an aphid colony following exposure to natural doses of alarm pheromone. In conclusion, our results confirm that changes to greenhouse gases impact chemical communication in the pea aphid, and could potentially have a cascade effect on interactions with higher trophic levels.

  1. Role of Pea Enation Mosaic Virus Coat Protein in the Host Plant and Aphid Vector

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    Juliette Doumayrou

    2016-11-01

    Full Text Available Understanding the molecular mechanisms involved in plant virus–vector interactions is essential for the development of effective control measures for aphid-vectored epidemic plant diseases. The coat proteins (CP are the main component of the viral capsids, and they are implicated in practically every stage of the viral infection cycle. Pea enation mosaic virus 1 (PEMV1, Enamovirus, Luteoviridae and Pea enation mosaic virus 2 (PEMV2, Umbravirus, Tombusviridae are two RNA viruses in an obligate symbiosis causing the pea enation mosaic disease. Sixteen mutant viruses were generated with mutations in different domains of the CP to evaluate the role of specific amino acids in viral replication, virion assembly, long-distance movement in Pisum sativum, and aphid transmission. Twelve mutant viruses were unable to assemble but were able to replicate in inoculated leaves, move long-distance, and express the CP in newly infected leaves. Four mutant viruses produced virions, but three were not transmissible by the pea aphid, Acyrthosiphon pisum. Three-dimensional modeling of the PEMV CP, combined with biological assays for virion assembly and aphid transmission, allowed for a model of the assembly of PEMV coat protein subunits.

  2. Assessing aphids potato virus Y-transmission efficiency: A new approach.

    Science.gov (United States)

    Boquel, Sébastien; Ameline, Arnaud; Giordanengo, Philippe

    2011-12-01

    In order to develop an alternative method to optimize the relative efficiency factor (REF) assessment, the efficiency of transmission of Potato virus Y (PVY) by seven aphid species was examined. In vitro micropropagated potato plantlets were used to experiment on phenotypically and genetically homogeneous material. Species-specific acquisition access period (AAP) on a PVY-infected plantlet was assessed for each aphid species using electrical penetration graph (EPG) technique. Aphid probing behaviour determined by EPG showed that Macrosiphum euphorbiae and Myzus persicae exhibited the shortest AAPs (15 and 11min, respectively) whereas Rhopalosiphum padi, Sitobion avenae, Brevicoryne brassicae and Acyrthosiphon pisum exhibited the longest ones (more than 30min). The transmission rate obtained for M. persicae (83.3%) was higher than the ones reported in the literature. REFs assessment showed that A. pisum and B. brassicae were poor efficient vectors while M. euphorbiae and S. avenae seemed to be efficient ones even though their respective REF were significantly lower than that of M. persicae. The species R. padi and A. fabae did not transmit PVY. The hypothesis assessed for M. euphorbiae and S. avenae and consisting in the compensation of a weak PVY-transmission efficiency by a higher number of vectors, was not supported. The use of this new method for REF evaluation and the need to consider aphid behaviour for such an assessment was discussed.

  3. Identification of aphid salivary proteins: a proteomic investigation of Myzus persicae.

    Science.gov (United States)

    Harmel, N; Létocart, E; Cherqui, A; Giordanengo, P; Mazzucchelli, G; Guillonneau, F; De Pauw, E; Haubruge, E; Francis, F

    2008-04-01

    The role of insect saliva in the first contact between an insect and a plant is crucial during feeding. Some elicitors, particularly in insect regurgitants, have been identified as inducing plant defence reactions. Here, we focused on the salivary proteome of the green peach aphid, Myzus persicae. Proteins were either directly in-solution digested or were separated by 2D SDS-PAGE before trypsin digestion. Resulting peptides were then identified by mass spectrometry coupled with database investigations. A homemade database was constituted of expressed sequence tags from the pea aphid Acyrtosiphon pisum and M. persicae. The databases were used to identify proteins related to M. persicae with a nonsequenced genome. This procedure enabled us to discover glucose oxidase, glucose dehydrogenase, NADH dehydrogenase, alpha-glucosidase and alpha-amylase in M. persicae saliva. The presence of these enzymes is discussed in terms of plant-aphid interactions.

  4. Aphid amino acid transporter regulates glutamine supply to intracellular bacterial symbionts.

    Science.gov (United States)

    Price, Daniel R G; Feng, Honglin; Baker, James D; Bavan, Selvan; Luetje, Charles W; Wilson, Alex C C

    2014-01-01

    Endosymbiotic associations have played a major role in evolution. However, the molecular basis for the biochemical interdependence of these associations remains poorly understood. The aphid-Buchnera endosymbiosis provides a powerful system to elucidate how these symbioses are regulated. In aphids, the supply of essential amino acids depends on an ancient nutritional symbiotic association with the gamma-proteobacterium Buchnera aphidicola. Buchnera cells are densely packed in specialized aphid bacteriocyte cells. Here we confirm that five putative amino acid transporters are highly expressed and/or highly enriched in Acyrthosiphon pisum bacteriocyte tissues. When expressed in Xenopus laevis oocytes, two bacteriocyte amino acid transporters displayed significant levels of glutamine uptake, with transporter ACYPI001018, LOC100159667 (named here as Acyrthosiphon pisum glutamine transporter 1, ApGLNT1) functioning as the most active glutamine transporter. Transporter ApGLNT1 has narrow substrate selectivity, with high glutamine and low arginine transport capacity. Notably, ApGLNT1 has high binding affinity for arginine, and arginine acts as a competitive inhibitor for glutamine transport. Using immunocytochemistry, we show that ApGLNT1 is localized predominantly to the bacteriocyte plasma membrane, a location consistent with the transport of glutamine from A. pisum hemolymph to the bacteriocyte cytoplasm. On the basis of functional transport data and localization, we propose a substrate feedback inhibition model in which the accumulation of the essential amino acid arginine in A. pisum hemolymph reduces the transport of the precursor glutamine into bacteriocytes, thereby regulating amino acid biosynthesis in the bacteriocyte. Structural similarities in the arrangement of hosts and symbionts across endosymbiotic systems suggest that substrate feedback inhibition may be mechanistically important in other endosymbioses.

  5. Transcriptome Analysis of Green Peach Aphid (Myzus persicae): Insight into Developmental Regulation and Inter-Species Divergence

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    Ji, Rui; Wang, Yujun; Cheng, Yanbin; Zhang, Meiping; Zhang, Hong-Bin; Zhu, Li; Fang, Jichao; Zhu-Salzman, Keyan

    2016-01-01

    Green peach aphid (Myzus persicae) and pea aphid (Acyrthosiphon pisum) are two phylogenetically closely related agricultural pests. While pea aphid is restricted to Fabaceae, green peach aphid feeds on hundreds of plant species from more than 40 families. Transcriptome comparison could shed light on the genetic factors underlying the difference in host range between the two species. Furthermore, a large scale study contrasting gene expression between immature nymphs and fully developed adult aphids would fill a previous knowledge gap. Here, we obtained transcriptomic sequences of green peach aphid nymphs and adults, respectively, using Illumina sequencing technology. A total of 2244 genes were found to be differentially expressed between the two developmental stages, many of which were associated with detoxification, hormone production, cuticle formation, metabolism, food digestion, and absorption. When searched against publically available pea aphid mRNA sequences, 13,752 unigenes were found to have no homologous counterparts. Interestingly, many of these unigenes that could be annotated in other databases were involved in the “xenobiotics biodegradation and metabolism” pathway, suggesting the two aphids differ in their adaptation to secondary metabolites of host plants. Conversely, 3989 orthologous gene pairs between the two species were subjected to calculations of synonymous and nonsynonymous substitutions, and 148 of the genes potentially evolved in response to positive selection. Some of these genes were predicted to be associated with insect-plant interactions. Our study has revealed certain molecular events related to aphid development, and provided some insight into biological variations in two aphid species, possibly as a result of host plant adaptation.

  6. Transcriptome analysis of green peach aphid (Myzus persicae: Insight into developmental regulation and inter-species divergence

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    Rui Ji

    2016-10-01

    Full Text Available Green peach aphid (Myzus persicae and pea aphid (Acyrthosiphon pisum are two phylogenetically closely related agricultural pests. While pea aphid is restricted to Fabaceae, green peach aphid feeds on hundreds of plant species from more than 40 families. Transcriptome comparison could shed light on the genetic factors underlying the difference in host range between the two species. Furthermore, a large scale study contrasting gene expression between immature nymphs and fully developed adult aphids would fill a previous knowledge gap. Here, we obtained transcriptomic sequences of green peach aphid nymphs and adults, respectively, using Illumina sequencing technology. A total of 2,244 genes were found to be differentially expressed between the two developmental stages, many of which were associated with detoxification, hormone production, cuticle formation, metabolism, food digestion and absorption. When searched against publically available pea aphid mRNA sequences, 13,752 unigenes were found to have no homologous counterparts. Interestingly, many of these unigenes that could be annotated in other databases were involved in the xenobiotics biodegradation and metabolism pathway, suggesting the two aphids differ in their adaptation to secondary metabolites of host plants. Conversely, 3,989 orthologous gene pairs between the two species were subjected to calculations of synonymous and nonsynonymous substitutions, and 148 of the genes potentially evolved in response to positive selection. Some of these genes were predicted to be associated with insect-plant interactions. Our study has revealed certain molecular events related to aphid development, and provided some insight into biological variations in two aphid species, possibly as a result of host plant adaptation.

  7. To feed or not to feed: plant factors located in the epidermis, mesophyll, and sieve elements influence pea aphid's ability to feed on legume species.

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    Alexander Schwarzkopf

    Full Text Available The pea aphid (Acyrthosiphon pisum Harris, a legume specialist, encompasses at least 11 genetically distinct sympatric host races. Each host race shows a preference for a certain legume species. Six pea aphid clones from three host races were used to localize plant factors influencing aphid probing and feeding behavior on four legume species. Aphid performance was tested by measuring survival and growth. The location of plant factors influencing aphid probing and feeding was determined using the electrical penetration graph (EPG technique. Every aphid clone performed best on the plant species from which it was originally collected, as well as on Vicia faba. On other plant species, clones showed intermediate or poor performance. The most important plant factors influencing aphid probing and feeding behavior were localized in the epidermis and sieve elements. Repetitive puncturing of sieve elements might be relevant for establishing phloem feeding, since feeding periods appear nearly exclusively after these repetitive sieve element punctures. A combination of plant factors influences the behavior of pea aphid host races on different legume species and likely contributes to the maintenance of these races.

  8. Transcriptomic and proteomic analyses of seasonal photoperiodism in the pea aphid

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    Gauthier J-P

    2009-09-01

    Full Text Available Abstract Background Aphid adaptation to harsh winter conditions is illustrated by an alternation of their reproductive mode. Aphids detect photoperiod shortening by sensing the length of the night and switch from viviparous parthenogenesis in spring and summer, to oviparous sexual reproduction in autumn. The photoperiodic signal is transduced from the head to the reproductive tract to change the fate of the future oocytes from mitotic diploid embryogenesis to haploid formation of gametes. This process takes place in three consecutive generations due to viviparous parthenogenesis. To understand the molecular basis of the switch in the reproductive mode, transcriptomic and proteomic approaches were used to detect significantly regulated transcripts and polypeptides in the heads of the pea aphid Acyrthosiphon pisum. Results The transcriptomic profiles of the heads of the first generation were slightly affected by photoperiod shortening. This suggests that trans-generation signalling between the grand-mothers and the viviparous embryos they contain is not essential. By analogy, many of the genes and some of the proteins regulated in the heads of the second generation are implicated in visual functions, photoreception and cuticle structure. The modification of the cuticle could be accompanied by a down-regulation of the N-β-alanyldopamine pathway and desclerotization. In Drosophila, modification of the insulin pathway could cause a decrease of juvenile hormones in short-day reared aphids. Conclusion This work led to the construction of hypotheses for photoperiodic regulation of the switch of the reproductive mode in aphids.

  9. Serratia symbiotica from the aphid Cinara cedri: a missing link from facultative to obligate insect endosymbiont.

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    Araceli Lamelas

    2011-11-01

    Full Text Available The genome sequencing of Buchnera aphidicola BCc from the aphid Cinara cedri, which is the smallest known Buchnera genome, revealed that this bacterium had lost its symbiotic role, as it was not able to synthesize tryptophan and riboflavin. Moreover, the biosynthesis of tryptophan is shared with the endosymbiont Serratia symbiotica SCc, which coexists with B. aphidicola in this aphid. The whole-genome sequencing of S. symbiotica SCc reveals an endosymbiont in a stage of genome reduction that is closer to an obligate endosymbiont, such as B. aphidicola from Acyrthosiphon pisum, than to another S. symbiotica, which is a facultative endosymbiont in this aphid, and presents much less gene decay. The comparison between both S. symbiotica enables us to propose an evolutionary scenario of the transition from facultative to obligate endosymbiont. Metabolic inferences of B. aphidicola BCc and S. symbiotica SCc reveal that most of the functions carried out by B. aphidicola in A. pisum are now either conserved in B. aphidicola BCc or taken over by S. symbiotica. In addition, there are several cases of metabolic complementation giving functional stability to the whole consortium and evolutionary preservation of the actors involved.

  10. Bacterial genes in the aphid genome: absence of functional gene transfer from Buchnera to its host.

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    Naruo Nikoh

    2010-02-01

    Full Text Available Genome reduction is typical of obligate symbionts. In cellular organelles, this reduction partly reflects transfer of ancestral bacterial genes to the host genome, but little is known about gene transfer in other obligate symbioses. Aphids harbor anciently acquired obligate mutualists, Buchnera aphidicola (Gammaproteobacteria, which have highly reduced genomes (420-650 kb, raising the possibility of gene transfer from ancestral Buchnera to the aphid genome. In addition, aphids often harbor other bacteria that also are potential sources of transferred genes. Previous limited sampling of genes expressed in bacteriocytes, the specialized cells that harbor Buchnera, revealed that aphids acquired at least two genes from bacteria. The newly sequenced genome of the pea aphid, Acyrthosiphon pisum, presents the first opportunity for a complete inventory of genes transferred from bacteria to the host genome in the context of an ancient obligate symbiosis. Computational screening of the entire A. pisum genome, followed by phylogenetic and experimental analyses, provided strong support for the transfer of 12 genes or gene fragments from bacteria to the aphid genome: three LD-carboxypeptidases (LdcA1, LdcA2,psiLdcA, five rare lipoprotein As (RlpA1-5, N-acetylmuramoyl-L-alanine amidase (AmiD, 1,4-beta-N-acetylmuramidase (bLys, DNA polymerase III alpha chain (psiDnaE, and ATP synthase delta chain (psiAtpH. Buchnera was the apparent source of two highly truncated pseudogenes (psiDnaE and psiAtpH. Most other transferred genes were closely related to genes from relatives of Wolbachia (Alphaproteobacteria. At least eight of the transferred genes (LdcA1, AmiD, RlpA1-5, bLys appear to be functional, and expression of seven (LdcA1, AmiD, RlpA1-5 are highly upregulated in bacteriocytes. The LdcAs and RlpAs appear to have been duplicated after transfer. Our results excluded the hypothesis that genome reduction in Buchnera has been accompanied by gene transfer to the

  11. Elevated CO2 decreases the response of the ethylene signaling pathway in Medicago truncatula and increases the abundance of the pea aphid.

    Science.gov (United States)

    Guo, Huijuan; Sun, Yucheng; Li, Yuefei; Liu, Xianghui; Zhang, Wenhao; Ge, Feng

    2014-01-01

    The performance of herbivorous insects is greatly affected by plant nutritional quality and resistance, which are likely to be altered by rising concentrations of atmospheric CO2 . We previously reported that elevated CO2 enhanced biological nitrogen (N) fixation of Medicago truncatula, which could result in an increased supply of amino acids to the pea aphid (Acyrthosiphon pisum). The current study examined the N nutritional quality and aphid resistance of sickle, an ethylene-insensitive mutant of M. truncatula with supernodulation, and its wild-type control A17 under elevated CO2 in open-top field chambers. Regardless of CO2 concentration, growth and amino acid content were greater and aphid resistance was lower in sickle than in A17. Elevated CO2 up-regulated N assimilation and transamination-related enzymes activities and increased phloem amino acids in both genotypes. Furthermore, elevated CO2 down-regulated expression of 1-amino-cyclopropane-carboxylic acid (ACC), sickle gene (SKL) and ethylene response transcription factors (ERF) genes in the ethylene signaling pathway of A17 when infested by aphids and decreased resistance against aphids in terms of lower activities of superoxide dismutase (SOD), peroxidase (POD), and polyphenol oxidase (PPO). Our results suggest that elevated CO2 suppresses the ethylene signaling pathway in M. truncatula, which results in an increase in plant nutritional quality for aphids and a decrease in plant resistance against aphids.

  12. Natural occurrence of entomophthoroid fungi of aphid pests on Medicago sativa L. in Argentina.

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    Manfrino, Romina G; Zumoffen, Leticia; Salto, César E; Lastra, Claudia C López

    2014-01-01

    Four species of entomophthoroid fungi, Pandora neoaphidis (Entomophthorales: Entomophthoraceae), Zoophthora radicans (Entomophthorales: Entomophthoraceae), Entomophthora planchoniana (Entomophthorales: Entomophthoraceae) and Neozygites fresenii (Neozygitales: Neozygitaceae) were found to infect Aphis craccivora, Therioaphis trifolii, and Acyrthosiphon pisum and unidentified species of Acyrthosiphon on lucerne in Argentina. Samples were collected from five sites (Ceres, Rafaela, Sarmiento, Monte Vera and Bernardo de Irigoyen) in the province of Santa Fe. In this study, Zoophthora radicans was the most important pathogen and was recorded mainly on Acyrthosiphon sp. Zoophthora radicans was successfully isolated and maintained in pure cultures. This study is the first report of entomophthoroid fungi infecting lucerne (Medicago sativa L.) aphids in Argentina.

  13. Compatible plant-aphid interactions: how aphids manipulate plant responses.

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    Giordanengo, Philippe; Brunissen, Laurence; Rusterucci, Christine; Vincent, Charles; van Bel, Aart; Dinant, Sylvie; Girousse, Christine; Faucher, Mireille; Bonnemain, Jean-Louis

    2010-01-01

    To access phloem sap, aphids have developed a furtive strategy, their stylets progressing towards sieve tubes mainly through the apoplasmic compartment. Aphid feeding requires that they overcome a number of plant responses, ranging from sieve tube occlusion and activation of phytohormone-signalling pathways to expression of anti-insect molecules. In addition to bypassing plant defences, aphids have been shown to affect plant primary metabolism, which could be a strategy to improve phloem sap composition in nutrients required for their growth. During compatible interactions, leading to successful feeding and reproduction, aphids cause alterations in their host plant, including morphological changes, modified resource allocation and various local as well as systemic symptoms. Repeated salivary secretions injected from the first probe in the epidermal tissue up to ingestion of sieve-tube sap may play a crucial role in the compatibility between the aphid and the plant.

  14. Sexual and asexual oogenesis require the expression of unique and shared sets of genes in the insect Acyrthosiphon pisum

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    Gallot Aurore

    2012-02-01

    Full Text Available Abstract Background Although sexual reproduction is dominant within eukaryotes, asexual reproduction is widespread and has evolved independently as a derived trait in almost all major taxa. How asexuality evolved in sexual organisms is unclear. Aphids, such as Acyrthosiphon pisum, alternate between asexual and sexual reproductive means, as the production of parthenogenetic viviparous females or sexual oviparous females and males varies in response to seasonal photoperiodism. Consequently, sexual and asexual development in aphids can be analyzed simultaneously in genetically identical individuals. Results We compared the transcriptomes of aphid embryos in the stages of development during which the trajectory of oogenesis is determined for producing sexual or asexual gametes. This study design aimed at identifying genes involved in the onset of the divergent mechanisms that result in the sexual or asexual phenotype. We detected 33 genes that were differentially transcribed in sexual and asexual embryos. Functional annotation by gene ontology (GO showed a biological signature of oogenesis, cell cycle regulation, epigenetic regulation and RNA maturation. In situ hybridizations demonstrated that 16 of the differentially-transcribed genes were specifically expressed in germ cells and/or oocytes of asexual and/or sexual ovaries, and therefore may contribute to aphid oogenesis. We categorized these 16 genes by their transcription patterns in the two types of ovaries; they were: i expressed during sexual and asexual oogenesis; ii expressed during sexual and asexual oogenesis but with different localizations; or iii expressed only during sexual or asexual oogenesis. Conclusions Our results show that asexual and sexual oogenesis in aphids share common genetic programs but diverge by adapting specificities in their respective gene expression profiles in germ cells and oocytes.

  15. Insulin-related peptide 5 is involved in regulating embryo development and biochemical composition in pea aphid with wing polyphenism

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    Shan-Shan eGuo

    2016-02-01

    Full Text Available In aphids there is a fecundity-dispersal trade-off between wingless and winged morphs. Recent research on the molecular mechanism of wing morphs associated with dispersal reveals that insulin receptors in the insulin signaling (IS pathway regulate alteration of wing morphs in planthoppers. However, little is known about whether genes in the IS pathway are involved in developmental regulation in aphid nymphs with different wing morphs. In this study, we show that expression of the insulin-related peptide 5 gene (Apirp5 affects biochemical composition and embryo development of wingless pea aphids, Acyrthosiphon pisum. After comparing expression levels of major genes in the IS pathway between third instar winged and wingless nymphs, we found that Apirp5 showed higher expression in head and thorax of the wingless nymphs than in the winged nymphs. Although microinjection treatment affects physical performance in aphids, nymphs with RNA interference of Apirp5 had less weight, smaller embryo size and higher carbohydrate and protein contents compared to control group. Comparison between winged and wingless nymphs showed a similar trend. These results indicate that Apirp5 is involved in embryo development and metabolic regulation in wing dimorphic pea aphid.

  16. Volatile communication in plant-aphid interactions.

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    de Vos, Martin; Jander, Georg

    2010-08-01

    Volatile communication plays an important role in mediating the interactions between plants, aphids, and other organisms in the environment. In response to aphid infestation, many plants initiate indirect defenses through the release of volatiles that attract ladybugs, parasitoid wasps, and other aphid-consuming predators. Aphid-induced volatile release in the model plant Arabidopsis thaliana requires the jasmonate signaling pathway. Volatile release is also induced by infection with aphid-transmitted viruses. Consistent with mathematical models of optimal transmission, viruses that are acquired rapidly by aphids induce volatile release to attract migratory aphids, but discourage long-term aphid feeding. Although the ecology of these interactions is well-studied, further research is needed to identify the molecular basis of aphid-induced and virus-induced changes in plant volatile release.

  17. Seasonal Changes in the Endosymbiotic Consortia of Aphids from the Genus Cinara

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    Martínez-Díaz, Vanesa; Latorre, Amparo; Gil, Rosario

    2016-01-01

    Buchnera aphidicola is the primary endosymbiont of aphids with which it maintains an obligate mutualistic symbiotic relationship. Insects also maintain facultative symbiotic relationships with secondary symbionts, and Serratia symbiotica is the most common in aphids. The presence of both symbionts in aphids of the subfamily Lachninae has been widely studied by our group. We examined two closely related aphids, Cinara tujafilina and C. cedri in the present study. Even though both B. aphidicola strains have similar genome sizes and gene contents, the genomes of the two S. symbiotica strains were markedly different. The SCc strain has the smallest genome known for this species, while SCt possesses a larger genome in an intermediate stage between the facultative S. symbiotica of Acyrthosiphon pisum (SAp) and the co-obligate S. symbiotica SCc. Aphids are vulnerable to high temperatures. Previous studies indicated that S. symbiotica SAp confers resistance to heat-shock stress. In order to clarify whether S. symbiotica strains from genus Cinara also play a role in heat stress protection, we performed a quantitative determination of the consortium Buchnera/Serratia from two geographically close populations, each of which belonged to the Cinara species examined, over two years in natural environments. We found no variation in the consortium from our C. cedri population, but a positive correlation between both endosymbiont densities and average daily temperatures in the C. tujafilina population. Even though S. symbiotica SCt may retain some protective role against heat stress, this does not appear to be due to the release of protective metabolites by cell lysis. PMID:27297891

  18. Increasing phosphorus supply is not the mechanism by which arbuscular mycorrhiza increase attractiveness of bean (Vicia faba) to aphids.

    Science.gov (United States)

    Babikova, Zdenka; Gilbert, Lucy; Randall, Kate C; Bruce, Toby J A; Pickett, John A; Johnson, David

    2014-10-01

    Arbuscular mycorrhizal (AM) fungi, important plant mutualists, provide plants with nutrients such as phosphorus (P) in return for carbon. AM fungi also enhance the attractiveness of plants to aphids via effects on emissions of plant volatiles used in aphid host location. We tested whether increased P uptake by plants is the mechanism through which AM fungi alter the volatile profile of plants and aphid behavioural responses by manipulating the availability of P and AM fungi to broad beans (Vicia faba L.) in a multi-factorial design. If AM fungi affect plant volatiles only via increased P acquisition, we predicted that the emission of volatiles and the attractiveness of mycorrhizal beans to aphids would be similar to those of non-mycorrhizal beans supplied with additional P. AM fungi and P addition increased leaf P concentrations by 40 and 24%, respectively. The production of naphthalene was less in mycorrhizal plants, regardless of P addition. By contrast, production of (S)-linalool, (E)-caryophyllene and (R)-germacrene D was less in plants colonized by AM fungi but only in the absence of P additions. The attractiveness of plants to pea aphids (Acyrthosiphon pisum Harris) was positively affected by AM fungi and correlated with the extent of root colonization; however, attractiveness was neither affected by P treatment nor correlated with leaf P concentration. These findings suggest that increased P uptake is not the main mechanism by which mycorrhiza increase the attractiveness of plants to aphids. Instead, the mechanism is likely to operate via AM fungi-induced plant systemic signalling.

  19. Increasing phosphorus supply is not the mechanism by which arbuscular mycorrhiza increase attractiveness of bean (Vicia faba) to aphids

    Science.gov (United States)

    Babikova, Zdenka; Gilbert, Lucy; Randall, Kate C.; Bruce, Toby J. A.; Pickett, John A.; Johnson, David

    2014-01-01

    Arbuscular mycorrhizal (AM) fungi, important plant mutualists, provide plants with nutrients such as phosphorus (P) in return for carbon. AM fungi also enhance the attractiveness of plants to aphids via effects on emissions of plant volatiles used in aphid host location. We tested whether increased P uptake by plants is the mechanism through which AM fungi alter the volatile profile of plants and aphid behavioural responses by manipulating the availability of P and AM fungi to broad beans (Vicia faba L.) in a multi-factorial design. If AM fungi affect plant volatiles only via increased P acquisition, we predicted that the emission of volatiles and the attractiveness of mycorrhizal beans to aphids would be similar to those of non-mycorrhizal beans supplied with additional P. AM fungi and P addition increased leaf P concentrations by 40 and 24%, respectively. The production of naphthalene was less in mycorrhizal plants, regardless of P addition. By contrast, production of (S)-linalool, (E)-caryophyllene and (R)-germacrene D was less in plants colonized by AM fungi but only in the absence of P additions. The attractiveness of plants to pea aphids (Acyrthosiphon pisum Harris) was positively affected by AM fungi and correlated with the extent of root colonization; however, attractiveness was neither affected by P treatment nor correlated with leaf P concentration. These findings suggest that increased P uptake is not the main mechanism by which mycorrhiza increase the attractiveness of plants to aphids. Instead, the mechanism is likely to operate via AM fungi-induced plant systemic signalling. PMID:25200735

  20. Do aphid carcasses on the backs of larvae of green lacewing work as chemical mimicry against aphid-tending ants?

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    Hayashi, Masayuki; Choh, Yasuyuki; Nakamuta, Kiyoshi; Nomura, Masashi

    2014-06-01

    Ants attack and exclude natural enemies of aphids in ant-aphid mutualisms. However, larvae of the green lacewing, Mallada desjardinsi, prey on the cowpea aphid, Aphis craccivora, without exclusion by aphid-tending ants. Lacewing larvae are protected from ants by carrying aphid carcasses on their backs. Here, we tested whether cuticular hydrocarbons (CHCs) of aphid carcasses affected the aggressiveness of aphid-tending ants. Aphid carcasses were washed with n-hexane to remove lipids. Lacewing larvae with washed aphid carcasses were attacked by aphid-tending ants more frequently than those with untreated aphid carcasses. We measured the aggressiveness of aphid-tending ants to lacewing larvae that were either carrying a piece of cotton wool (a dummy aphid carcass) treated with CHCs from aphids or lacewing larvae, or carrying aphid carcasses. The rates of attack by ants on lacewing larvae carrying CHCs of aphids or aphid carcasses were lower than that of attack on lacewing larvae with conspecific CHCs. Chemical analysis by gas chromatography/mass spectrometry showed similarity of CHCs between aphids and aphid carcasses. These results suggest that aphid carcasses on the backs of lacewing larvae function via chemical camouflage to limit attacks by aphid-tending ants.

  1. Efficacy of Chemical Mimicry by Aphid Predators Depends on Aphid-Learning by Ants.

    Science.gov (United States)

    Hayashi, Masayuki; Nomura, Masashi; Nakamuta, Kiyoshi

    2016-03-01

    Chemical mimicry is an effective strategy when signal receivers recognize and discriminate models by relying on chemical cues. Some aphid enemies mimic the cuticular chemicals of aphids through various means thus avoiding detection and attack by aphid-tending ants. However, because ants have been reported to learn the chemical signatures of aphids in order to distinguish the aphids, the efficacy of chemical mimicry is predicted to depend on the experience of the ants that had tended aphids. The present study tested this hypothesis using two predator species: larvae of the green lacewing Mallada desjardinsi, and larvae of the ladybeetle Scymnus posticalis. Lacewing larvae carry the carcasses of aphids on which they have preyed upon their backs, and these function via chemical camouflage to reduce the aggressiveness of aphid-tending ants toward the larvae. Ladybeetle larvae reportedly produce a covering of wax structures, and their chemicals appear to attenuate ant aggression. We examined whether the behavior of the ant Tetramorium tsushimae toward these predators changed depending on their aphid-tending experience. Ants moderated their aggressiveness toward both predators when they had previously tended aphids, indicating that chemical mimicry by both aphid predators is dependent on previous experience of the ants in tending aphids. Chemical mimicry by the predators of ant-tended aphids is therefore considered to exploit learning-dependent aphid recognition systems of ants.

  2. Stylet penetration activities by aphids

    NARCIS (Netherlands)

    Tjallingii, W.F.

    1985-01-01

    The composition of stylet penetration behaviour in aphids and its possible role in food-plant selection is the subject of these studies. Evidence is presented that the labium is devoid of external chemoreceptors (Chapter 1). In addition to other morphological data (Wensler & Filshie, 1969; Wensler,

  3. Monitoring of aphid flight activities in seed potato crops in Serbia

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    Andja Vucetic

    2013-07-01

    Full Text Available Aphid flight activities in seed potato fields have been studied by the yellow water traps. It is a good method for monitoring aphids as vectors of viruses, but this study also showed it is a suitable method for insect-diversity research. During the four-year studies, over 11.500 specimens were collected and a total of 107 different taxa of aphids were identified. The most abundant species were polyphagous species, such as: Acyrthosiphon pisum (Haris, Aphis fabae Scopoli, Aphis gossypii Glover and Brachycaudus helichrysi (Kaltenbach. The results of the studies show that diversity of aphids in different regions of Serbia is similar regardless of the altitude and the diversity of terrain. At most sites it ranged from 2 to 3. The highest value was recorded in Begeč, locality in northern part of Serbia, in year 2008, and it was 2.92. The maximum values of the Shannon-Weaver diversity index at all sites were recorded in the first weeks of the monitoring of aphid flight activities. Morisita-Horn similarity index shows no significant differences between sites regardless of altitudes. The sites are grouped by year, not by similarity of relief. In spite of these results, the Chi-square analysis showed highly significant difference in vector frequencies among seasons and sites with more pronounced differences for PVY. As a consequence of differences in vector frequencies, the vector pressure index in some regions was different also. The number of vectors and vector pressure index vary depending on the altitude of localities. At localities at altitudes under 1000 m, they were high. The highest index was at Kotraža, locality in central part of Serbia, in 2007, when PVY index exceeded the value of 180, while for PLRV it was 60. At high altitudes on mountain Golija, above 1100 m, the number of aphids was low, as well as the vector pressure index which indicates that these regions are suitable for producing virus-free seed potato.

  4. Altruistic defence behaviours in aphids

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    Brodeur Jacques

    2010-01-01

    Full Text Available Abstract Background Altruistic anti-predatory behaviours pose an evolutionary problem because they are costly to the actor and beneficial to the recipients. Altruistic behaviours can evolve through indirect fitness benefits when directed toward kin. The altruistic nature of anti-predatory behaviours is often difficult to establish because the actor can obtain direct fitness benefits, or the behaviour could result from selfish coercion by others, especially in eusocial animals. Non-eusocial parthenogenetically reproducing aphids form colonies of clone-mates, which are ideal to test the altruistic nature of anti-predatory defence behaviours. Many aphids release cornicle secretions when attacked by natural enemies such as parasitoids. These secretions contain an alarm pheromone that alerts neighbours (clone-mates of danger, thereby providing indirect fitness benefits to the actor. However, contact with cornicle secretions also hampers an attacker and could provide direct fitness to the actor. Results We tested the hypothesis that cornicle secretions are altruistic by assessing direct and indirect fitness consequences of smearing cornicle secretions onto an attacker, and by manipulating the number of clone-mates that could benefit from the behaviour. We observed parasitoids, Aphidius rhopalosiphi, foraging singly in patches of the cereal aphid Sitobion avenae of varied patch size (2, 6, and 12 aphids. Aphids that smeared parasitoids did not benefit from a reduced probability of parasitism, or increase the parasitoids' handling time. Smeared parasitoids, however, spent proportionately more time grooming and less time foraging, which resulted in a decreased host-encounter and oviposition rate within the host patch. In addition, individual smearing rate increased with the number of clone-mates in the colony. Conclusions Cornicle secretions of aphids were altruistic against parasitoids, as they provided no direct fitness benefits to secretion

  5. Glucolipids of Zea mays and Pisum sativum

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    Morohashi, Y.; Bandurski, R.S.

    1976-06-01

    The glucolipids formed upon feeding (U--/sup 14/C)glucose to embryos of Zea mays were partially characterized with respect to: (a) metabolic turnover, (b) acid lability, (c) phosphorus content, (d) chromatographic properties, and (e) hydrolysis products. The chloroform--methanol-soluble-assimilated radioactivity was examined specifically for occurrence of a glycosylated prenol phosphate. With the extraction conditions used, no evidence was found for formation of a glucosylated prenol phosphate. Several, as yet unidentified, acid-labile glucolipids undergoing metabolic turnover were observed. Four diglycerides were characterized as hydrolysis products of a fraction that contained /sup 14/C-glucose and phosphorus, and was subject to metabolic turnover. Examination of the 1-butanol-soluble glucolipids from pea (Pisum sativum) seedlings also demonstrated anionic glucolipids, evidencing metabolic turnover but none with the properties of glucosylated prenol phosphate.

  6. Aphid alarm pheromone as a cue for ants to locate aphid partners.

    Directory of Open Access Journals (Sweden)

    François J Verheggen

    Full Text Available The mutualistic relationships that occur between myrmecophilous aphids and ants are based on the rich food supply that honeydew represents for ants and on the protection they provide against aphid natural enemies. While aphid predators and parasitoids actively forage for oviposition sites by using aphid semiochemicals, scouts of aphid-tending ant species would also benefit from locating honeydew resources by orienting toward aphid pheromone sources. The present study aims to provide additional information on the use of Aphis fabae alarm pheromone, i.e. (E-β-farnesene (EβF, by ant scouts. The perception and behavioral impact of EβF on Lasius niger were investigated using electroantennography and two bio-assays measuring their attraction and orientation towards aphid semiochemicals. Pronounced electrical depolarizations were observed from L. niger scout antennae to stimulations of A. fabae alarm pheromone, while other sesquiterpenes elicited weak or no responses. L. niger scouts were significantly attracted toward EβF in a four-arm olfactometer, as well as in an two-choice bioassay. These laboratory results suggest for the first time that low amounts of aphid alarm pheromone can be used by L. niger scouts as a cue indicating the presence of aphid colonies and could therefore mediate the aphid-ant partnership in the field.

  7. Developmental origin and evolution of bacteriocytes in the aphid-Buchnera symbiosis.

    Directory of Open Access Journals (Sweden)

    Christian Braendle

    2003-10-01

    Full Text Available Symbiotic relationships between bacteria and insect hosts are common. Although the bacterial endosymbionts have been subjected to intense investigation, little is known of the host cells in which they reside, the bacteriocytes. We have studied the development and evolution of aphid bacteriocytes, the host cells that contain the endosymbiotic bacteria Buchnera aphidicola. We show that bacteriocytes of Acyrthosiphon pisum express several gene products (or their paralogues: Distal-less, Ultrabithorax/Abdominal-A, and Engrailed. Using these markers, we find that a subpopulation of the bacteriocytes is specified prior to the transmission of maternal bacteria to the embryo. In addition, we discovered that a second population of cells is recruited to the bacteriocyte fate later in development. We experimentally demonstrate that bacteriocyte induction and proliferation occur independently of B. aphidicola. Major features of bacteriocyte development, including the two-step recruitment of bacteriocytes, have been conserved in aphids for 80-150 million years. Furthermore, we have investigated two cases of evolutionary loss of bacterial symbionts: in one case, where novel extracellular, eukaryotic symbionts replaced the bacteria, the bacteriocyte is maintained; in another case, where symbionts are absent, the bacteriocytes are initiated but not maintained. The bacteriocyte represents an evolutionarily novel cell fate, which is developmentally determined independently of the bacteria. Three of five transcription factors we examined show novel expression patterns in bacteriocytes, suggesting that bacteriocytes may have evolved to express many additional transcription factors. The evolutionary transition to a symbiosis in which bacteria and an aphid cell form a functional unit, similar to the origin of plastids, has apparently involved extensive molecular adaptations on the part of the host cell.

  8. Rag1 aphid resistant soybeans alter the movement and distribution of soybean aphid (Hemiptera: Aphididae).

    Science.gov (United States)

    Whalen, Rebecca; Harmon, Jason P

    2012-12-01

    Herbivorous insects often move and distribute according to the quality of the plant they are on, and this behavior could influence interactions with plants bred for herbivore resistance. However, when an insect is normally considered sedentary, less is known about the potential importance of movement. We performed experiments to determine if a resistant soybean variety alters the movement and distribution, both within and between plants, of the soybean aphid Aphis glycines Matsumura. We did this by counting apterous aphids on leaves of resistant and susceptible soybean plants across several days. In individual plant tests aphid distribution was different between susceptible and resistant soybeans. Most notably aphids on resistant plants were quickly found off the original leaf on which they were placed and were ultimately distributed throughout the resistant soybean. Aphids on susceptible plants, however, tended to stay on their initial leaf of placement. Follow up experiments indicated this was primarily because of the movement of individuals and not differential demography on various plant parts. In experiments where aphids were able to walk to an adjacent plant there appeared to be a net movement of aphids off resistant plants and on to susceptible plants. Aphid populations on susceptible plants were higher when the plant was adjacent to a resistant plant than when adjacent to another susceptible plant. The effect of resistant plants on aphid movement and distribution could lead to unintended side-effects such as greater spread of plant viruses or altered effectiveness of biological control agents.

  9. RNAi-mediated plant protection against aphids.

    Science.gov (United States)

    Yu, Xiu-Dao; Liu, Zong-Cai; Huang, Si-Liang; Chen, Zhi-Qin; Sun, Yong-Wei; Duan, Peng-Fei; Ma, You-Zhi; Xia, Lan-Qin

    2016-06-01

    Aphids (Aphididae) are major agricultural pests that cause significant yield losses of crop plants each year by inflicting damage both through the direct effects of feeding and by vectoring harmful plant viruses. Expression of double-stranded RNA (dsRNA) directed against suitable insect target genes in transgenic plants has been shown to give protection against pests through plant-mediated RNA interference (RNAi). Thus, as a potential alternative and effective strategy for insect pest management in agricultural practice, plant-mediated RNAi for aphid control has received close attention in recent years. In this review, the mechanism of RNAi in insects and the so far explored effective RNAi target genes in aphids, their potential applications in the development of transgenic plants for aphid control and the major challenges in this regard are reviewed, and the future prospects of using plant-mediated RNAi for aphid control are discussed. This review is intended to be a helpful insight into the generation of aphid-resistant plants through plant-mediated RNAi strategy. © 2016 Society of Chemical Industry.

  10. AphID (Lucid key) http://AphID.AphidNet.org

    Science.gov (United States)

    This peer-reviewed web site concentrates on the 66 adult alate and apterous aphids that are the world's most cosmopolitan and polyphagous species. The site includes fact sheets about the various aphids species, a glossary of terms helpful to the student, hundreds of photographs and illustrations, a...

  11. Expansion of genes encoding piRNA-associated argonaute proteins in the pea aphid: diversification of expression profiles in different plastic morphs.

    Directory of Open Access Journals (Sweden)

    Hsiao-Ling Lu

    Full Text Available Piwi-interacting RNAs (piRNAs are known to regulate transposon activity in germ cells of several animal models that propagate sexually. However, the role of piRNAs during asexual reproduction remains almost unknown. Aphids that can alternate sexual and asexual reproduction cycles in response to seasonal changes of photoperiod provide a unique opportunity to study piRNAs and the piRNA pathway in both reproductive modes. Taking advantage of the recently sequenced genome of the pea aphid Acyrthosiphon pisum, we found an unusually large lineage-specific expansion of genes encoding the Piwi sub-clade of Argonaute proteins. In situ hybridisation showed differential expressions between the duplicated piwi copies: while Api-piwi2 and Api-piwi6 are "specialised" in germ cells their most closely related copy, respectively Api-piwi5 and Api-piwi3, are expressed in the somatic cells. The differential expression was also identified in duplicated ago3: Api-ago3a in germ cells and Api-ago3b in somatic cells. Moreover, analyses of expression profiles of the expanded piwi and ago3 genes by semi-quantitative RT-PCR showed that expressions varied according to the reproductive types. These specific expression patterns suggest that expanded aphid piwi and ago3 genes have distinct roles in asexual and sexual reproduction.

  12. Root-Lesion Nematodes Suppress Cabbage Aphid Population Development by Reducing Aphid Daily Reproduction.

    Science.gov (United States)

    Hol, W H G; Raaijmakers, Ciska E; Mons, Ilse; Meyer, Katrin M; van Dam, Nicole M

    2016-01-01

    Empirical studies have shown that belowground feeding herbivores can affect the performance of aboveground herbivores in different ways. Often the critical life-history parameters underlying the observed performance effects remain unexplored. In order to better understand the cause for the observed effects on aboveground herbivores, these ecological mechanisms must be better understood. In this study we combined empirical experiments with a modeling approach to analyze the effect of two root feeding endoparasitic nematodes with different feeding strategies on the population growth of the aboveground feeding specialist aphid Brevicoryne brassicae on Brassica nigra. The aim was to test whether emerging differences in life history characteristics (days until reproduction, daily reproduction) would be sufficient to explain observed differences in aphid population development on plants with and without two species of nematodes. Aphid numbers were lower on plants with Pratylenchus penetrans in comparison to aphid numbers on plants with Meloidogyne spp. A dedicated experiment showed that aphid daily reproduction was lower on plants with P. penetrans (3.08 offspring female(-1) day(-1)) in comparison to both uninfested plants and plants with Meloidogyne spp. (3.50 offspring female(-1) day(-1)). The species-specific reduction of aphid reproduction appeared independent of changes in amino acids, soluble sugars or the glucosinolate sinigrin in the phloem. An individual-based model revealed that relatively small differences in reproduction rate per female were sufficient to yield a similar difference in aphid populations as was found in the empirical experiments.

  13. Aphid-AutoEPG software for analysing electrically monitored feeding behaviour of aphids

    Directory of Open Access Journals (Sweden)

    Toni Prüfer

    2014-06-01

    Full Text Available Aphid-AutoEPG is a new software program, developed to acquire and automatically analyse electrical penetration graph (EPG signals used for monitoring plant penetration by aphids. Characteristically EPG signals include waveforms that allow one to study the effects of plants on the acquisition and transmission of viruses, plant protection substances on pests and identify the location of resistance in plants to aphids. The success of electrical monitoring arises from the fact that different species of aphids generate similar EPG patterns. But the visual analysis of EPG waveforms in recorded signals is very time consuming, which has greatly hampered the wider application of EPG technology. To overcome this Aphid-AutoEPG software was developed, which has been extensively tested using data files for several different species of aphids, M. persicae, A. frangulae gossypii, M. albifrons, S. avenae, B. brassicae and N. ribis-nigri. The results have also been compared with visual analyses using Stylet+ software. When used in combination with the user friendly correction options Aphid-AutoEPG is not only easy to use but can also result in a considerable saving in terms of time.

  14. Early interactions during the encounter of plants, aphids and arboviruses.

    Science.gov (United States)

    Bak, Aurélie; Martinière, Alexandre; Blanc, Stéphane; Drucker, Martin

    2013-06-01

    Aphids infest many plants and cause damage by depriving them of nutrients and by transmitting many viral diseases. Aphid infestation and arbovirus transmission are controlled by establishment (or not) of a compatible reaction between the insects and the plants. This reaction is the result of defense reactions of the plant and counter-defense reactions of the parasite. Contrarily to plant-bacteria, plant-fungi and plant-herbivorous insects pathosystems, the plant-aphid pathosystem is understudied, although recent advances have begun to uncover some of its details. Especially the very early steps in plant-aphid interactions are hardly known. We here resume the present knowledge of these interactions. We discuss further how an aphid-transmitted plant virus that is transmitted during the first moments of the plant-aphid encounter, might help to study the very early plant aphid interactions.

  15. Plant-aphid interactions under elevated CO2: some cues from aphid feeding behavior

    Directory of Open Access Journals (Sweden)

    Yu-Cheng eSun

    2016-04-01

    Full Text Available Although the increasing concentration of atmospheric carbon dioxide (CO2 accelerates the accumulation of carbohydrates and increases the biomass and yield of C3 crop plants, it also reduces their nitrogen status. The consequent changes in primary and secondary metabolites affect the palatability of host plants and the feeding of herbivorous insects. Aphids are phloem feeders and are considered the only feeding guild that positively responds to elevated CO2. In this review, we consider how elevated CO2 modifies host defenses, nutrients, and water-use efficiency by altering concentrations of the phytohormones jasmonic acid, salicylic acid, ethylene, and abscisic acid. We will describe how these elevated CO2-induced changes in defenses, nutrients, and water status facilitate specific stages of aphid feeding, including penetration, phloem-feeding, and xylem absorption. We conclude that a better understanding of the effects of elevated CO2 on aphids and on aphid damage to crop plants will require research on the molecular aspects of the interaction between plant and aphid but also research on aphid interactions with their intra- and inter-specific competitors and with their natural enemies.

  16. Pathogenicity of conidia-based preparations of entomopathogenic fungi against the greenhouse pest aphids: green peach aphid, melon aphid, and foxglove aphid

    Science.gov (United States)

    Seeking new isolates of entomopathogenic fungi with greater virulence against greenhouse aphid pests than those currently registered in North America for control of these insects, single-dose screening assays of 44 selected fungal isolates and 4 commercially available strains were conducted against ...

  17. Evolving aphids: one genome-one organism insects or holobionts?

    Directory of Open Access Journals (Sweden)

    M Mandrioli

    2013-01-01

    Full Text Available Aphids have obligate mutualistic relationships with microorganisms that provide them with essential substances lacking in their diet, together with symbionts conferring them conditional adaptive advantages related, for instance, to the thermal tolerance and to the resistance to parasitoid wasps. The presence/absence of a secondary symbiont may have a relevant phenotypic effect so that aphid microbial symbionts constitute a sort of second genome with its own genetic inheritance. On the whole, genes important for aphid survival and reproduction are not uniquely present in the aphid nuclear and mitochondrial genomes, but also in the chromosomes of each symbiont. As a consequence, aphids should be viewed as holobionts with an extended genome (the hologenome including the host and its symbiotic microbiome. In this connection, the true unit of selection in evolution must be considered the aphid holobiont, in place of the single host as individual separated from its symbionts.

  18. Presence of the Aphid, Chaetosiphon fragaefolii, on Strawberry in Argentina

    OpenAIRE

    Claudia CÉDOLA; Grecob, Nancy

    2010-01-01

    Seasonal abundance of the strawberry aphid complex under different agronomic practices in the outskirts of La Plata, Argentina was studied on strawberry, Fragaria x ananassa Duchesne (Rosales: Rosaceae). Aphid densities were low in strawberry fields in which insecticides and fungicides were used. In addition to Aphis gossypii, Aphis fabae, Mysus persicae and Macrosiphum euphorbiae, the aphid, Chaetosiphon fragaefolii (Cockerell) (Homoptera: Aphididae), was recorded for the first time in this ...

  19. Descriptive Epizootiology of an Aphid Mycosis

    OpenAIRE

    Soper, Richard S.; Macleod, D. M.

    1981-01-01

    The epizootiology of Entomophthora canarjensis Macleod, Tyrrell, & Soper in populations of the woolly pine needle aphid (Schizolachnus piniradiatae (Davidson)) was investigated during a 5-year period in an isolated plantation of red pine (Pinus resinosa Aitj in northern Ontario. Climatic factors did not limit the spread of the fungus; the major controlling factors were the density of the fungus inoculum and the density and spatial distribution of ti1tl host. An epizootic killed nearly 100 per...

  20. Anomalous stylet punctures of phloem sieve elements by aphids

    NARCIS (Netherlands)

    Tjallingii, W.F.; Gabrys, B.

    1999-01-01

    A deviating type of potential drop (pd), i.e. the electrically recorded intracellular punctures during the pathway phase of plant penetration by aphids, is described and discussed. This so-called repetitive pd (R-pd) has been observed in 4 aphid species, two on herbs and two on sycamore. Apart from

  1. Aphid-plant interactions at phloem level, a behavioural study.

    NARCIS (Netherlands)

    Prado, E.C.

    1997-01-01

    Aphid-plant interactions occurring during plant penetration, or probing, have determined the evolution of these insects as well as the abilities of plants to survive huge densities of these insects. For aphids, as phloem sap feeders, the interactions at sieve element level must be of special importa

  2. Detection of novel QTLs for foxglove aphid resistance in soybean

    Science.gov (United States)

    Foxglove aphid, Aulacorthum solani (Kaltenbach), is a Hemipteran insect that infected a wide variety of plants worldwide and caused serious yield losses in crops. The objective of this study was to identify the putative QTL for foxglove aphid resistance in wild soybean, PI 366121, (Glycine soja Sieb...

  3. Predator efficiency reconsidered for a ladybird-aphid system

    Directory of Open Access Journals (Sweden)

    Pavel eKindlmann

    2015-03-01

    Full Text Available Some experiments indicate that ladybirds can significantly suppress aphid abundance. For example, exclusion of predators by caging aphid-infested plants repeatedly results in higher aphid populations and faster aphid population growth rates. However, aphidophagous ladybirds have never proved effective in controlling aphid populations in the field, which is consistent with the theoretical prediction that long-lived predators cannot be effective in controlling a short-lived prey (the generation time ratio hypothesis, GTR. To resolve this paradox, field experiments, involving two species of ladybirds, Coccinella septempunctata bruckii and Harmonia axyridis were used to determine their efficiency in suppressing populations of the aphid, Aphis gossypii, on small shrubs of Hibiscus syriacus under natural conditions. Instead of by caging, the effect of each ladybird species on aphid population dynamics was determined by removing all the eggs of C. septempunctata from 8 shrubs, those of H. axyridis from a further 8 shrubs, all those of both species from an additional 12 shrubs and leaving the eggs on 6 control shrubs. These predators did not have a negative effect on the peak numbers of the aphids. Thus one should be cautious when interpreting the results of cage experiments, used to assess the efficiency of predators in reducing the abundance of their prey.

  4. Effects of Herbivore Stress by Acyrthosiphon pisum on the Contents of Tannin and Physiological Activity in Different Alfalfa Cultivars%豌豆蚜刺吸胁迫对不同苜蓿品种体内单宁含量及生理活性的影响

    Institute of Scientific and Technical Information of China (English)

    武德功; 王森山; 刘长仲; 胡桂馨; 杜军利; 贺春贵

    2011-01-01

    It is necessary to study the relationship between aphid stress and physiological activity in different alfalfa yarieties for breeding of resistant alfalfa varieties and sustainable control of aphids. The dynamics of Malondialdehyde (MDA) and Tannin contents and the activities of protective enzymes (Superoxide dismutase (SOD), Peroxidase (POD)) were studied in the leaves of four alfalfa cultivars, Gannong No. 5 (G5), Gannong No. 3 (G3), Gloden Empress (JH), and Hunter River (Hu), infested by pea aphid,Acyrthosiphon pisum Harris. Results show that the MDA contents of resistant variety (G5) were lower than that of the susceptible variety (Hu) and low resistant varieties (G3) when their leaves were piercingsucked by the aphid. The Tannin contents of resistant variety (G5) and the susceptible variety (Hu) were lower than that of the low resistant ones (G3 and JH), While the SOD and POD activities in the susceptible variety (Hu) appeared lower than that of the resistant variety (G5) and low resistant varieties (G3,JH). Throughout the period of aphid attacks, the activities of SOD and POD of all varieties rose initially then declined, whereas the dynamics of MDA and Tannin contents of four alfalfa cultivars were irregular.Therefore, under the aphid stress, the contents of MDA and the activity of SOD, POD in susceptible, low resistant and resistant varieties are closely related to the aphid-resistance of alfalfa. These biochemical markers may be used as physiological indices for aphid-resistance appraisal. However, the relationship between Tannin contents and aphid-resistance of alfalfa requires further research.%通过对甘农5号(G5)、甘农3号(G3)、金皇后(JH)和猎人河(Hu)4种不同抗蚜苜蓿(Medicago sativa L.)品种受豌豆蚜(Acyrthosiphon pisum)胁迫后其叶片内丙二醛(MDA)和单宁含量及防御性酶(超氧化物歧化酶(SOD)和过氧化物酶(POD))活性的动态变化研究,以期明确各项生理指标与抗虫性之间的关系.结果表

  5. Ants farm subterranean aphids mostly in single clone groups

    DEFF Research Database (Denmark)

    Ivens, Aniek B.F.; Kronauer, Daniel Jan Christoph; Pen, Ido

    2012-01-01

    a single aphid species, a significantly higher percentage than expected from a random distribution. Over 60% of these single-species mounds had a single aphid clone, and clones tended to persist across subsequent years. Whenever multiple species/clones co-occurred in the same mound, they were spatially...... separated with more than 95% of the aphid chambers containing individuals of a single clone. Conclusions L. flavus “husbandry” is characterized by low aphid “livestock” diversity per colony, especially at the nest-chamber level, but it lacks the exclusive monocultures known from other cultivation mutualisms...... benefitting the domesticated aphids as long as their clone-mates reproduce successfully. The cost-benefit logic of this type of polyculture husbandry has striking analogies with human farming practices based on slaughtering young animals for meat to maximize milk-production by a carefully regulated adult...

  6. Two odorant-binding proteins mediate the behavioural response of aphids to the alarm pheromone (E-ß-farnesene and structural analogues.

    Directory of Open Access Journals (Sweden)

    Yu Feng Sun

    Full Text Available BACKGROUND: Aphids are agricultural pests of great economical interest. Alternatives to insecticides, using semiochemicals, are of difficult applications. In fact, sex pheromones are of little use as aphids reproduce partenogenetically most of the time. Besides, the alarm pheromone, (E-ß-farnesene for a great number of species, is difficult to synthesize and unstable in the environment. The search for novel semiochemicals to be used in population control can be efficiently approached through the study of the olfactory system at the biochemical level. Recently odorant-binding proteins (OBPs have been shown to play a central role in olfactory recognition, thus becoming the target of choice for designing new semiochemicals. METHODOLOGY/PRINCIPAL FINDINGS: To address the question of how the alarm message is recognised at the level of OBPs, we have tested 29 compounds, including (E-ß-farnesene, in binding assays with 6 recombinant proteins and in behaviour experiments. We have found that good repellents bind OBP3 and/or OBP7, while non repellents present different spectra of binding. These results have been verified with two species of aphids, Acyrthosiphon pisum and Myzus persicae, both using (E-ß-farnesene as the alarm pheromone. CONCLUSIONS: Our results represent further support to the idea (so far convincingly demonstrated only in Drosophila that OBPs are involved in decoding the chemical information of odorants and pheromones, and for the first time provide such evidence in other insect species and using wild-type insects. Moreover, the data offer guidelines and protocols for the discovery of potential alarm pheromones, using ligand-binding assays as a preliminary screening before subjecting selected compounds to behaviour tests.

  7. Two Odorant-Binding Proteins Mediate the Behavioural Response of Aphids to the Alarm Pheromone (E)-ß-farnesene and Structural Analogues

    Science.gov (United States)

    Qiao, Hui Li; Iovinella, Immacolata; Yang, Shao Xiang; Ling, Yun; Riviello, Lea; Battaglia, Donatella; Falabella, Patrizia; Yang, Xin Ling; Pelosi, Paolo

    2012-01-01

    Background Aphids are agricultural pests of great economical interest. Alternatives to insecticides, using semiochemicals, are of difficult applications. In fact, sex pheromones are of little use as aphids reproduce partenogenetically most of the time. Besides, the alarm pheromone, (E)-ß-farnesene for a great number of species, is difficult to synthesize and unstable in the environment. The search for novel semiochemicals to be used in population control can be efficiently approached through the study of the olfactory system at the biochemical level. Recently odorant-binding proteins (OBPs) have been shown to play a central role in olfactory recognition, thus becoming the target of choice for designing new semiochemicals. Methodology/Principal Findings To address the question of how the alarm message is recognised at the level of OBPs, we have tested 29 compounds, including (E)-ß-farnesene, in binding assays with 6 recombinant proteins and in behaviour experiments. We have found that good repellents bind OBP3 and/or OBP7, while non repellents present different spectra of binding. These results have been verified with two species of aphids, Acyrthosiphon pisum and Myzus persicae, both using (E)-ß-farnesene as the alarm pheromone. Conclusions Our results represent further support to the idea (so far convincingly demonstrated only in Drosophila) that OBPs are involved in decoding the chemical information of odorants and pheromones, and for the first time provide such evidence in other insect species and using wild-type insects. Moreover, the data offer guidelines and protocols for the discovery of potential alarm pheromones, using ligand-binding assays as a preliminary screening before subjecting selected compounds to behaviour tests. PMID:22427877

  8. Aphids (Hemiptera, Aphididae) on ornamental plants in greenhouses in Bulgaria.

    Science.gov (United States)

    Yovkova, Mariya; Petrović-Obradović, Olivera; Tasheva-Terzieva, Elena; Pencheva, Aneliya

    2013-01-01

    Investigations on the species composition and host range of aphids on ornamental greenhouse plants in Bulgaria was conducted over a period of five years, from 2008 to 2012. Twenty greenhouses, growing ornamentals for landscaping, plant collections and other purposes were observed. They were located in the regions of Sofia, Plovdiv, Smolyan, Pavlikeni, Varna and Burgas. The total number of collected aphid samples was 279. Their composition included 33 aphid species and one subspecies from 13 genera and 5 subfamilies. Twenty-eight species were found to belong to subfamily Aphidinae. Almost 70 % of all recorded species were polyphagous. The most widespread aphid species was Myzus persicae, detected in 13 greenhouses all year round, followed by Aulacorthum solani (10 greenhouses) and Aphis gossypii (9 greenhouses). The widest host range was shown by Myzus persicae (43 hosts), Aulacorthum solani (32 hosts) and Aulacorthum circumflexum (23 hosts). The list of host plants includes 114 species from 95 genera and 58 families. The greatest variety of aphid species was detected on Hibiscus (9 species). Out of all aphid samples 12.9 % were collected on Hibiscus and 6.8 %, on Dendranthema. The greatest variety of aphid species was detected on Hibiscus (9 species). Periphyllus californiensis and Aphis (Aphis) fabae mordvilkoi are reported for the first time for Bulgaria. Furthermore, Aphis spiraecola has been found in new localities and has widened its host range in this country.

  9. Multiple cues for winged morph production in an aphid metacommunity.

    Directory of Open Access Journals (Sweden)

    Mohsen Mehrparvar

    Full Text Available Environmental factors can lead individuals down different developmental pathways giving rise to distinct phenotypes (phenotypic plasticity. The production of winged or unwinged morphs in aphids is an example of two alternative developmental pathways. Dispersal is paramount in aphids that often have a metapopulation structure, where local subpopulations frequently go extinct, such as the specialized aphids on tansy (Tanacetum vulgare. We conducted various experiments to further understand the cues involved in the production of winged dispersal morphs by the two dominant species of the tansy aphid metacommunity, Metopeurum fuscoviride and Macrosiphoniella tanacetaria. We found that the ant-tended M. fuscoviride produced winged individuals predominantly at the beginning of the season while the untended M. tanacetaria produced winged individuals throughout the season. Winged mothers of both species produced winged offspring, although in both species winged offspring were mainly produced by unwinged females. Crowding and the presence of predators, effects already known to influence wing production in other aphid species, increased the percentage of winged offspring in M. tanacetaria, but not in M. fuscoviride. We find there are also other factors (i.e. temporal effects inducing the production of winged offspring for natural aphid populations. Our results show that the responses of each aphid species are due to multiple wing induction cues.

  10. Aphid Transmission of the Ontario Isolate of Plum Pox Virus.

    Science.gov (United States)

    Lowery, D Thomas; Vickers, Patricia M; Bittner, Lori A; Stobbs, Lorne W; Foottit, Robert G

    2015-10-01

    Utilization of timed virus acquisition access probes in studies of plum pox virus (PPV) transmission by aphids demonstrated that endemic species transmitted the virus readily from plum, Prunus domestica (L.) Batsch; peach, P. persica (L.); or dwarf flowering almond, P. glandulosa Thunberg., to peach seedlings. The green peach aphid, Myzus persicae (Sulzer), was shown to be the most efficient vector. Acquisition of virus by green peach aphids from infected peach leaves resulted in 18-28% infected peach seedlings, while aphids previously fed on infected leaves of plum transferred virus to 36% of peach seedlings. Although the spirea aphid, Aphis spiraecola (Patch), was a less efficient vector than M. persicae it is perhaps more important for the spread of PPV due to its greater abundance and occurrence earlier in the season when peach trees are thought to be more susceptible to infection. Virus transmission rates varied depending on the virus source and healthy test plant species. In contrast to many previous studies, aphid inoculation of the experimental host Nicotiana benthamiana Domin occurred at a low rate, never exceeding 4%. Acquisition of PPV by M. persicae from infected peach fruit was greatly reduced compared with acquisition from leaves. The results of this research indicate that the Ontario isolate of PPV-D is readily transmissible by aphids to peach and natural spread of the virus needs to be considered in future management or eradication programs.

  11. Abundancia y riqueza específica de pulgones (Hemiptera: Aphididae y sus parasitoides en diferentes genotipos y estados fenologicos del garbanzo Species richness and abundance of aphids (Hemiptera: Aphididae and their parasitoids in different genotypes and at different growth stages of chickpea

    Directory of Open Access Journals (Sweden)

    V. E. Mazzuferi

    2011-12-01

    Full Text Available Los áfidos son insectos perjudiciales tanto por la succión de savia como por la transmisión de enfermedades. Los objetivos de este trabajo fueron conocer las especies de áfidos y sus parasitoides presentes en diferentes genotipos de garbanzo, calcular la incidencia del parasitismo e informar sobre las fluctuaciones poblacionales de pulgones y parasitoides en relación a los estados fenológicos del cultivo. El estudio se realizó durante 2006 y 2007 en San Marcos Sierras (Córdoba. Se evaluaron siete líneas y dos cultivares sembrados en un diseño en bloques completamente aleatorizados con tres repeticiones. Cada 15 días se colectaron manualmente áfidos y "momias" presentes en 10 plantas seleccionadas al azar, de cada genotipo y bloque. Se determinaron 13 especies de áfidos. En 2006 se observó mayor abundancia y riqueza de especies que en 2007. Las especies numéricamente dominantes fueron: Acyrthosiphon pisum y A. kondoi. Solamente cinco especies colonizaron el cultivo. El cultivar Chañaritos presentó la mayor abundancia de insectos en los dos años agrícolas, y los genotipos M60 y M75 mostraron la mayor riqueza de especies. En ambos años, los pulgones estuvieron presentes durante la etapa reproductiva del cultivo. Se registraron tres especies de parasitoides y se estimó un 35% de parasitismo total.Aphids may damage plants by sucking plant juices or by transmitting diseases. The aim of this study was to obtain further information about aphid species and their parasitoids in different genotypes of chickpea, calculate the incidence of parasitism and report on fluctuating populations (from aphids and parasitoid in relation to plant phenology. The study was undertaken during 2006 and 2007 in San Marcos Sierras (Cordoba. Seven lines and two cultivars of chickpea were evaluated. Crop plots were planted following a completely randomized design block with 3 replicates. Every two weeks different developmental stages of aphids and "mummies

  12. Galling Aphids (Hemiptera: Aphidoidea in China: Diversity and Host Specificity

    Directory of Open Access Journals (Sweden)

    Jing Chen

    2012-01-01

    Full Text Available Gall formation is an interesting plant response to aphid feeding. This paper presents a review of galling aphids in China. Altogether, 157 species and subspecies in ten families and subfamilies are found to induce galls on their host plants. As many as 39% species are endemic to China. The Eriosomatinae include the highest percentage of gall-inducing species. The great diversity of gall morphology may be described in terms of five characteristics: type, site, size, shape, and structure. The host association and host specificity of galling aphids are also discussed.

  13. Impact of Rag1 aphid resistant soybeans on Binodoxys communis (Hymenoptera: Braconidae), a parasitoid of soybean aphid (Hemiptera: Aphididae).

    Science.gov (United States)

    Ghising, Kiran; Harmon, Jason P; Beauzay, Patrick B; Prischmann-Voldseth, Deirdre A; Helms, Ted C; Ode, Paul J; Knodel, Janet J

    2012-04-01

    Multiple strategies are being developed for pest management of the soybean aphid, Aphis glycines Matsumura; however, there has been little published research thus far to determine how such strategies may influence each other, thereby complicating their potential effectiveness. A susceptible soybean (Glycine max L.) variety without the Rag1 gene and a near isogenic resistant soybean variety with the Rag1 gene were evaluated in the laboratory for their effects on the fitness of the soybean aphid parasitoid, Binodoxys communis (Gahan). The presence or absence of the Rag1 gene was verified by quantifying soybean aphid growth. To test for fitness effects, parasitoids were allowed to attack soybean aphids on either a susceptible or resistant plant for 24 h and then aphids were kept on the same plant throughout parasitoid development. Parasitoid fitness was measured by mummy and adult parasitoid production, adult parasitoid emergence, development time, and adult size. Parasitoids that attacked soybean aphids on susceptible plants produced more mummies, more adult parasitoids, and had a higher emergence rate compared with those on resistant plants. Adult parasitoids that emerged from resistant plants took 1 d longer and were smaller compared with those from susceptible plants. This study suggests that biological control by B. communis may be compromised when host plant resistance is widely used for pest management of soybean aphids.

  14. For the Aphid fauna in the territory of Yenisei river basin. Communication 1. Aphids on coniferous plants

    Directory of Open Access Journals (Sweden)

    A. V. Gurov

    2016-02-01

    Full Text Available The paper reports on new and previously not well-known data on insufficiently studied fauna of aphids living on coniferous trees in Central Siberia of the basin of Yenisei river. This region is the extensive transect of latitudinal geographic zones from semi-desert in the South to the arctic deserts in the North. That is why this region is very peculiar. This is the reason for insufficient study of regional entomological fauna. Aphids (Homoptera: Aphidoideaare a very taxonomically and ecologically heterogeneous group of insects. The aphids living on conifer trees are notstudied completely on the territory of Yenisei basin. Due to this, the studying of not well-known and economicallyimportant aphids is actual. For example, the insufficient study of regional aphids is confirmed by the fact, that duringthree weeks only of the work for INTAS-94-0930 Project two new aphid species were found and described on thisterritory. Also, the new species of family Mindaridae, which was described in Mongolia in 1980, was found in Siberiafor the first time. These finds indicate the real possibility to describe an interesting conifer aphid complex in the absolutely unstudied forested territory between Angara and Lower Tunguska rivers. Geographical location, dates ofcollection and feeding preferences of different species are described. A general review of Yenisei basin Siberian aphidfauna is suggested for the first time ever.

  15. Identification of Soybean Resources of Resistance to Aphids

    Institute of Scientific and Technical Information of China (English)

    WU Tian-long; MA Xiao-hong; YAO Lu-ming; WANG Biao

    2009-01-01

    Four soybean [Glycine max (L.) Merr.] cultivars with soybean aphid resistance (Aphis glycines Matsmura), P189, P203, P574,and P746, were identified in field test, choice test, and non-choice test. The grade of resistance to aphids and the damage index of P189, P203, and P746 were significantly different from the susceptible cultivars (P=0.05). P574 and P746 showed antibiosis resistance, preventing aphids from reproducing on the plants. P203 showed antixenosis resistance, preventing aphids from reproducing in field test and choice test, but susceptible in non-choice test. Population development on plants was significantly different in field test, choice test, and non-choice test, which was caused by different selective pressures.

  16. Smells like aphids: orchid flowers mimic aphid alarm pheromones to attract hoverflies for pollination

    Science.gov (United States)

    Stökl, Johannes; Brodmann, Jennifer; Dafni, Amots; Ayasse, Manfred; Hansson, Bill S.

    2011-01-01

    Most insects are dependent on chemical communication for activities such as mate finding or host location. Several plants, and especially orchids, mimic insect semiochemicals to attract insects for unrewarded pollination. Here, we present a new case of pheromone mimicry found in the terrestrial orchid Epipactis veratrifolia. Flowers are visited and pollinated by several species of aphidophagous hoverflies, the females of which also often lay eggs in the flowers. The oviposition behaviour of these hoverflies is mainly guided by aphid-derived kairomones. We show that the flowers produce α- and β-pinene, β-myrcene and β-phellandrene, and that these compounds attract and induce oviposition behaviour in female hoverflies. This floral odour profile is remarkably similar to the alarm pheromone released by several aphid species, such as Megoura viciae. We therefore suggest that E. veratrifolia mimics aphid alarm pheromones to attract hoverflies for pollination; this is the first time, to our knowledge, that such a case of mimicry has been demonstrated. PMID:20943694

  17. Smells like aphids: orchid flowers mimic aphid alarm pheromones to attract hoverflies for pollination.

    Science.gov (United States)

    Stökl, Johannes; Brodmann, Jennifer; Dafni, Amots; Ayasse, Manfred; Hansson, Bill S

    2011-04-22

    Most insects are dependent on chemical communication for activities such as mate finding or host location. Several plants, and especially orchids, mimic insect semiochemicals to attract insects for unrewarded pollination. Here, we present a new case of pheromone mimicry found in the terrestrial orchid Epipactis veratrifolia. Flowers are visited and pollinated by several species of aphidophagous hoverflies, the females of which also often lay eggs in the flowers. The oviposition behaviour of these hoverflies is mainly guided by aphid-derived kairomones. We show that the flowers produce α- and β-pinene, β-myrcene and β-phellandrene, and that these compounds attract and induce oviposition behaviour in female hoverflies. This floral odour profile is remarkably similar to the alarm pheromone released by several aphid species, such as Megoura viciae. We therefore suggest that E. veratrifolia mimics aphid alarm pheromones to attract hoverflies for pollination; this is the first time, to our knowledge, that such a case of mimicry has been demonstrated.

  18. Mulches reduce aphid-borne viruses and whiteflies in cantaloupe

    OpenAIRE

    Summers, Charles G.; Mitchell, Jeffrey P.; Stapleton, James J.

    2005-01-01

    We compared reflective plastic and wheat straw mulches with conventional bare soil for managing aphid-borne virus diseases and silverleaf whitefly in cantaloupe. The occurrence of aphid-borne virus diseases was significantly reduced with both mulches as opposed to bare soil, and reflective plastic performed better than wheat straw. Silverleaf whitefly numbers, both adults and nymphs, were reduced equally by plastic mulch and wheat straw, and were significantly lower than with bare soil. Refle...

  19. Biological control of tortricids and aphids in strawberries

    DEFF Research Database (Denmark)

    Sigsgaard, Lene; Enkegaard, Annie; Eilenberg, Jørgen;

    Cropping practice and biological control can contribute to reduced pesticide use in strawberries. Organic strawberries are less attacked by strawberry tortricid and buckwheat flower strips can augment its natural enemies. Against shallot aphid the two-spot ladybird is promising.......Cropping practice and biological control can contribute to reduced pesticide use in strawberries. Organic strawberries are less attacked by strawberry tortricid and buckwheat flower strips can augment its natural enemies. Against shallot aphid the two-spot ladybird is promising....

  20. Burdock fructooligosaccharide induces stomatal closure in Pisum sativum.

    Science.gov (United States)

    Guo, Yanling; Guo, Moran; Zhao, Wenlu; Chen, Kaoshan; Zhang, Pengying

    2013-09-12

    Burdock fructooligosaccharide (BFO) isolated from the root tissue of Arctium lappa is a reserve carbohydrate that can induce resistance against a number of plant diseases. Stomatal closure is a part of plant innate immune response to restrict bacterial invasion. In this study, the effects of BFO on stomata movement in Pisum sativum and the possible mechanisms were studied with abscisic acid (ABA) as a positive control. The results showed that BFO could induce stomatal closure accompanied by ROS and NO production, as is the case with ABA. BFO-induced stomatal closure was inhibited by pre-treatment with L-NAME (N(G)-nitro-L-arginine methyl ester, hydrochloride; nitric oxide synthase inhibitor) and catalase (hydrogen peroxide scavenger). Exogenous catalase completely restricted BFO-induced production of ROS and NO in guard cells. In contrast, L-NAME prevented the rise in NO levels but only partially restricted the ROS production. These results indicate that BFO-induced stomatal closure is mediated by ROS and ROS-dependent NO production.

  1. Evaluation of SRAP markers for mapping of Pisum sativum L.

    Directory of Open Access Journals (Sweden)

    María Fernanda Guindon

    2016-09-01

    Full Text Available Linkage maps have become important tools for genetic studies. With the aim of evaluating the SRAP (sequence-related amplified polymorphism technique for linkage mapping in Pisum sativum L., a F2 mapping population derived from an initial cross between cvs. DDR11 and Zav25 was generated. A total of 25 SRAP primer combinations were evaluated in 45 F2 plants and both parental lines, generating 208 polymorphic bands/markers. The markers were analyzed by the chi-square goodness-of-fit test to check the expected Mendelian segregation ratio. The resulting linkage map consists of 112 genetic markers distributed in 7 linkage groups (LGs, covering a total of 528.8 cM. The length of the LGs ranged from 47.6 to 144.3 cM (mean 75.54 cM, with 9 to 34 markers. The linkage map developed in this study indicates that the SRAP marker system could be applied to mapping studies of pea.

  2. Processing Pisum sativum seed storage protein precursors in vitro

    Institute of Scientific and Technical Information of China (English)

    YANGLIJUN; CDOMONEY; 等

    1990-01-01

    The profile of polypeptides separated by SDS-PAGE from seed of major crop species such as pea(Pisum sativum) is complex,resulting from cleavage (processing) of precursors expressed from multiple copies of genes encoding vicilin and legumin,the major storage globulins.Translation in vitro of mRNAs hybridselected from mid-maturation pea seed RNAs by defined vicilin and legumin cDNA clones provided precursor molecules that were cleaved in vitro by a cell-free protease extract obtained from similar stage seed;the derived polypeptides were of comparable sizes to those observed in vivo.The feasibility of transcribing mRNA in vitro from a cDNA clone and cleavage in vitro of the derived translation products was established for a legumin clone,providing a method for determining polypeptide products of an expressed sequence.This approach will also be useful for characterising cleavage site requirements since modifications an readily be introduced at the DNA level.

  3. Control Four Species of Aphid on Vegetables with Diaeretiella rapae (McIntosh) (Hymenoptera:Braconidae)%菜蚜茧蜂对4种蔬菜蚜虫的控制作用研究

    Institute of Scientific and Technical Information of China (English)

    张立猛; 田泽华; 计思贵; 谷星慧; 周文兵; 杨海林

    2016-01-01

    菜蚜茧蜂(Diaeretiella rapae)是蔬菜蚜虫的重要天敌。为了明确菜蚜茧蜂对我国常见4种蔬菜蚜虫的控制作用,通过室内试验,研究了菜蚜茧蜂对萝卜蚜、甘蓝蚜、豌豆蚜和蚕豆蚜的寄生作用。结果表明:菜蚜茧蜂对萝卜蚜和甘蓝蚜具有较好的控制作用,放蜂后21 d,其寄生率多在20%以上;对豌豆蚜的寄生作用较弱,放蜂后21 d,寄生率最高不超过10%;对蚕豆蚜寄生率最低,多在1%左右,只有极少数蚜虫被寄生。%Diaeretiella rapae, an important parasitoid of aphids in the world, was released with 6 ratio to controlLipaphis erysimi, Brevicoryne brassicae,Acyrthosiphon pisum andAphis craccivorain Yuxi City Yunnan Province. The results showed that the parasitoid could controlLipaphis erysimi andBrevicoryne brassicae availably, and the parasitism was above 20% after releasing the parasitoid in 21 days, but the parasitism was only 10% to controlAcyrthosiphon pisum, and only 1% to controlAphis craccivora. The results provided evidence to control the aphids on vegetables by releasingDiaeretiella rapae(McIntosh).

  4. Preparing soft-bodied arthropods for microscope examination: Aphids (Insecta: Hemiptera: Aphididae)

    Science.gov (United States)

    Proper identification of aphids (Hemiptera: Aphididae) require preparation of the specimen on a microscope slide. This training video provides visual instruction on how to prepare aphid specimens on microscope slides for examination and indentification. Steps ranging from collection, specimen clear...

  5. Agronomy of strip intercropping broccoli with alyssum for biological control of aphids

    Science.gov (United States)

    Organic broccoli growers in California typically control aphids by intercropping broccoli with strips of alyssum (Lobularia maritima (L.) Desv.) which attracts hoverflies (Diptera: Syrphidae) that are important predators of aphids. A three year study with transplanted organic broccoli in Salinas, ...

  6. New data on aphid fauna (Hemiptera, Aphididae) in Algeria.

    Science.gov (United States)

    Laamari, Malik; d'Acier, Armelle Coeur; Jousselin, Emmanuelle

    2013-01-01

    A survey of aphids was carried out during the period 2008-2011 in different regions of Algeria by collecting and identifying aphids and their host plants. Aphids were collected from 46 host plants. Forty-six species were reported including thirty-six species which were recorded for the first time in this country and thirty species which were recorded for the first time in the Maghreb (North Africa). This study extends the number of known Algerian aphid to 156 species.

  7. Ethylene production and peroxidase activity in aphid-infested barley.

    Science.gov (United States)

    Argandoña, V H; Chaman, M; Cardemil, L; Muñoz, O; Zúñiga, G E; Corcuera, L J

    2001-01-01

    The purpose of this work was to investigate whether ethylene is involved in the oxidative and defensive responses of barley to the aphids Schizaphis graminum (biotype C) and Rhopalophum padi. The effect of aphid infestation on ethylene production was measured in two barley cultivars (Frontera and Aramir) that differ in their susceptibility to aphids. Ethylene evolution was higher in plants infested for 16 hr than in plants infested for 4 hr in both cultivars. Under aphid infestation, the production of ethylene was higher in cv. Frontera than in Aramir, the more aphid susceptible cultivar. Ethylene production also increases with the degree of infestation. Maximum ethylene evolution was detected after 16 hr when plants were infested with 10 or more aphids. Comparing the two species of aphids, Schizaphis graminum induced more ethylene evolution than Rhopalosiphum padi. Infestation with S. graminum increased hydrogen peroxide content and total soluble peroxidase activity in cv. Frontera, with a maximum level of H2O2 observed after 20 min of infestation and the maximum in soluble peroxidase activity after 30 min of infestation. When noninfested barley seedlings from cv. Frontera were exposed to ethylene, an increase in hydrogen peroxide and in total peroxidase activity was detected at levels similar to those of infested plants from cv. Frontera. When noninfested plants were treated with 40 ppm of ethylene, the maximum levels of H2O2 and soluble peroxidase activity were at 10 and 40 min, respectively. Ethylene also increased the activity of both cell-wall-bound peroxidases types (ionically and covalently bound), comparable with infestation. These results suggest that ethylene is involved in the oxidative responses of barley plants induced by infestation.

  8. Cereal aphid colony turnover and persistence in winter wheat.

    Directory of Open Access Journals (Sweden)

    Linton Winder

    Full Text Available An understanding of spatial and temporal processes in agricultural ecosystems provides a basis for rational decision-making with regards to the management and husbandry of crops, supporting the implementation of integrated farming strategies. In this study we investigated the spatial and temporal distribution of aphid pests (Sitobion avenae and Metopolophium dirhodum within winter wheat fields. Using an intensive sampling programme we investigated distributions at both the small (single shoot and large (field scales. Within two fields, a grid with 82 locations was established (area 120 m by 168 m. At each location, 25 shoots were individually marked and aphid counts by observation conducted on 21 and 22 occasions as the crop matured, resulting in 43,050 and 45,100 counts being conducted in the two fields respectively. We quantified field scale spatial distributions, demonstrating that spatial pattern generally emerged, with temporal stability being both species- and field- dependent. We then measured turnover of colonies at the small (individual shoot and large (field scales by comparing consecutive pairs of sampling occasions. Four turnover categories were defined: Empty (no aphids recorded on either occasion; Colonised (aphids recorded on the second occasion but not the first; Extinction (aphids recorded on the first occasion but not the second; Stable (aphids recorded on both occasions. At the field scale, population stability soon established, but, at the small scale there was a consistently high proportion of unoccupied shoots with considerable colonisation and extinction and low stability. The redistribution of aphids within the crop at the local scale is a vulnerability which could be used to disrupt population development--by mediating exposure to ground-active natural enemies and by incurring a metabolic cost caused by the physiological demands to re-establish on a nearby host plant.

  9. National Plant Diagnostic Network, Taxonomic training videos: Aphids under the microscope - overview

    Science.gov (United States)

    Training is a critical part of aphid (Hemiptera: Aphididae) identification. This training video provides provides an overview of general aphid morphology by using a compound microscope. The narrator discusses and highlights structures on the aphid that are important to make a species identification....

  10. Aphids (Homoptera, Aphidodea inhabiting the shrubs of Pinus mugo Turra in the green area of Lublin. Part II. Domination and frequency of aphids, their natural enemies and the injuries caused by aphids

    Directory of Open Access Journals (Sweden)

    Aneta Sławińska

    2012-12-01

    Full Text Available Observations were conducted in the years 1999-2001 on the shrubs Pinus mugo Turra growing in the green areas of Lublin in two sites (street and park. The purpose of the studies was to establish the domination and frequency of aphids, their effect on the decorative character of shrubs and the occurrence of the aphidophagous arthropods in the aphid colonies inhabiting mountain pine. It was found out that Schizolachnus pineti F. was the dominating species in the street site (A, while Cinara pini L. dominated in the park site (B. The decorative character of shrubs was clearly lowered only by aphids S. pineti. Predatory arthropods occurred in aphid colonies inhabiting the shrubs P. mugo. Their population in both sites was low, that is why they probably had little influence on limiting the aphid population. Parasitic Hymenoptera of I and II degrees obtained from a culture of aphid mummies were more numerous in the street site.

  11. Pea (Pisum sativum L. in the Genomic Era

    Directory of Open Access Journals (Sweden)

    Robert J. Redden

    2012-04-01

    Full Text Available Pea (Pisum sativum L. was the original model organism used in Mendel’s discovery (1866 of the laws of inheritance, making it the foundation of modern plant genetics. However, subsequent progress in pea genomics has lagged behind many other plant species. Although the size and repetitive nature of the pea genome has so far restricted its sequencing, comprehensive genomic and post genomic resources already exist. These include BAC libraries, several types of molecular marker sets, both transcriptome and proteome datasets and mutant populations for reverse genetics. The availability of the full genome sequences of three legume species has offered significant opportunities for genome wide comparison revealing synteny and co-linearity to pea. A combination of a candidate gene and colinearity approach has successfully led to the identification of genes underlying agronomically important traits including virus resistances and plant architecture. Some of this knowledge has already been applied to marker assisted selection (MAS programs, increasing precision and shortening the breeding cycle. Yet, complete translation of marker discovery to pea breeding is still to be achieved. Molecular analysis of pea collections has shown that although substantial variation is present within the cultivated genepool, wild material offers the possibility to incorporate novel traits that may have been inadvertently eliminated. Association mapping analysis of diverse pea germplasm promises to identify genetic variation related to desirable agronomic traits, which are historically difficult to breed for in a traditional manner. The availability of high throughput ‘omics’ methodologies offers great promise for the development of novel, highly accurate selective breeding tools for improved pea genotypes that are sustainable under current and future climates and farming systems.

  12. Relationship of soybean aphid (Hemiptera: Aphididae) to soybean plant nutrients, landscape structure, and natural enemies.

    Science.gov (United States)

    Noma, Takuji; Gratton, Claudio; Colunga-Garcia, Manuel; Brewer, Michael J; Mueller, Emily E; Wyckhuys, Kris A G; Heimpel, George E; O'Neal, Matthew E

    2010-02-01

    In the north central United States, populations of the exotic soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), are highly variable across space, complicating effective aphid management. In this study we examined relationships of plant nutrients, landscape structure, and natural enemies with soybean aphid abundance across Iowa, Michigan, Minnesota, and Wisconsin, representing the range of conditions where soybean aphid outbreaks have occurred since its introduction. We sampled soybean aphid and its natural enemies, quantified vegetation land cover and measured soybean nutrients (potassium [K] and nitrogen [N]) in 26 soybean sites in 2005 and 2006. Multiple regression models found that aphid abundance was negatively associated with leaf K content in 2005, whereas it was negatively associated with habitat diversity (Simpson's index) and positively associated with leaf N content in 2006. These variables accounted for 25 and 27% of aphid variability in 2005 and 2006, respectively, suggesting that other sources of variability are also important. In addition, K content of soybean plants decreased with increasing prevalence of corn-soybean cropland in 2005, suggesting that landscapes that have a high intensification of agriculture (as indexed by increasing corn and soybean) are more likely to have higher aphid numbers. Soybean aphid natural enemies, 26 species of predators and parasitoids, was positively related to aphid abundance; however, enemy-to-aphid abundance ratios were inversely related to aphid density, suggesting that soybean aphids are able to escape control by resident natural enemies. Overall, soybean aphid abundance was most associated with soybean leaf chemistry and landscape heterogeneity. Agronomic options that can ameliorate K deficiency and maintaining heterogeneity in the landscape may reduce aphid risk.

  13. Particle film affects black pecan aphid (Homoptera: Aphididae) on pecan.

    Science.gov (United States)

    Cottrell, Ted E; Wood, Bruce W; Reilly, Charles C

    2002-08-01

    Three species of aphids attack pecan foliage, Carya illinoensis (Wang.) K. Koch, and cause economic damage. We tested a kaolin-based particle film against one of these aphid species, black pecan aphid, Melanocallis caryaefoliae (Davis). Effect of particle film on host selection, adult mortality, and production of nymphs by M. caryaefoliae was tested on seedling pecans in the laboratory. Fewer M. caryaefoliae adults selected treated foliage compared with untreated foliage. A higher percentage of adults that did select treated foliage were recovered from upper leaf surfaces compared with the percentage of adults recovered from upper leaf surfaces of untreated leaves. Observations with a microscope revealed an accumulation of particle film on aphid body parts, especially on tarsi, and strongly suggests that aphid mobility was restricted. Adult mortality was higher on treated foliage and led to an overall decrease in production of nymphs on those seedlings. In addition, we measured spectral properties of treated seedling pecan foliage. Light reflectance by treated foliage was increased and absorptance decreased compared with control foliage whereas transmittance of light through control and particle film-treated leaves was similar. We did not detect any phytotoxic effect on pecan due to application of particle film.

  14. Mechanisms regulating caste differentiation in an aphid social system.

    Science.gov (United States)

    Shibao, Harunobu; Kutsukake, Mayako; Matsuyama, Shigeru; Fukatsu, Takema; Shimada, Masakazu

    2010-01-01

    For evolution and maintenance of the social systems of insect colonies, caste production should be controlled in response to external cues so that caste ratio in the colony is kept at an optimal range. Recent developments using artificial diet rearing techniques have revealed an underlying mechanism for adaptive control of caste production in a social aphid, Tuberaphis styraci, which has a sterile soldier caste in the 2(nd) instar. Aphid density was the proximate cue that acts on 1(st) instar nymphs and embryos to induce soldier differentiation. The final determination of soldier differentiation occurred postnatally, probably at a late 1(st) instar stage. Direct contact stimuli from live non-soldier aphids mediated the density effect. While coexisting non-soldiers facilitated soldier differentiation in 1(st) instar nymphs, coexisting soldiers acted to suppress such differentiation. These results suggest that caste production in aphid colonies is controlled by positive and negative feedback mechanisms consisting of density-dependent induction and suppression of soldier differentiation. Here, we demonstrate the mechanisms that coordinate aphid society, and provide a striking case of clonal superorganism system where simple responses of colony members to local extrinsic stimuli are integrated into a highly organized regulation of the whole colony.

  15. Virulent Diuraphis noxia Aphids Over-Express Calcium Signaling Proteins to Overcome Defenses of Aphid-Resistant Wheat Plants.

    Science.gov (United States)

    Sinha, Deepak K; Chandran, Predeesh; Timm, Alicia E; Aguirre-Rojas, Lina; Smith, C Michael

    2016-01-01

    The Russian wheat aphid, Diuraphis noxia, an invasive phytotoxic pest of wheat, Triticum aestivum, and barley, Hordeum vulgare, causes huge economic losses in Africa, South America, and North America. Most acceptable and ecologically beneficial aphid management strategies include selection and breeding of D. noxia-resistant varieties, and numerous D. noxia resistance genes have been identified in T. aestivum and H. vulgare. North American D. noxia biotype 1 is avirulent to T. aestivum varieties possessing Dn4 or Dn7 genes, while biotype 2 is virulent to Dn4 and avirulent to Dn7. The current investigation utilized next-generation RNAseq technology to reveal that biotype 2 over expresses proteins involved in calcium signaling, which activates phosphoinositide (PI) metabolism. Calcium signaling proteins comprised 36% of all transcripts identified in the two D. noxia biotypes. Depending on plant resistance gene-aphid biotype interaction, additional transcript groups included those involved in tissue growth; defense and stress response; zinc ion and related cofactor binding; and apoptosis. Activation of enzymes involved in PI metabolism by D. noxia biotype 2 aphids allows depletion of plant calcium that normally blocks aphid feeding sites in phloem sieve elements and enables successful, continuous feeding on plants resistant to avirulent biotype 1. Inhibition of the key enzyme phospholipase C significantly reduced biotype 2 salivation into phloem and phloem sap ingestion.

  16. Selection of entomopathogenic fungi for aphid control.

    Science.gov (United States)

    Vu, Van Hanh; Hong, Suk Il; Kim, Keun

    2007-12-01

    Twelve strains of entomopathogenic fungi such as Lecanicillium lecanii, Paecilomyces farinosus, Beauveria bassiana, Metarhizium anisopliae, Cordyceps scarabaeicola, and Nomuraea rileyi were screened for aphid control. At 25 degrees C and 75% relative humidity (RH), among tested entomopathogenic fungi, L. lecanii 41185 showed the highest virulent pathogenicity for both Myzus persicae and Aphis gossypii, and their control values were both nearly 100% 5 and 2 d after treatment, respectively. Moreover, at an RH of 45% and in a wide temperature range (20-30 degrees C), L. lecanii 41185 also exhibited the highest virulence to M. persicae. The control value of M. persicae and the 50% lethal time (LT50) decreased significantly as the applied conidial concentration increased. The 50% lethal concentration (LC50) of the conidial suspension of this fungus was determined to be 6.55x10(5) conidia/ml. The control values of M. persicae resulting from the application of 1x10(7) and 1x10(8) conidia/ml were nearly the same and were significantly higher than that of 1x10(6) conidia/ml. The tested entomopathogenic fungi grew in a broad temperature range (15-30 degrees C). Lecanicillium strains showed optimum growth at 25 degrees C. The aerial conidia of Lecanicillium strains also could germinate in a broad temperature range (15-30 degrees C) and L. lecanii 41185 was the only strain with conidial germination at 35 degrees C.

  17. Molecular Cloning, Expression Pattern and Polymorphisms of NADPH-Cytochrome P450 Reductase in the Bird Cherry-Oat Aphid Rhopalosiphum padi (L..

    Directory of Open Access Journals (Sweden)

    Kang Wang

    Full Text Available NADPH-cytochrome P450 reductase (CPR plays an important role in the cytochrome P450 (CYP-mediated metabolism of endogenous and exogenous substrates. CPR has been found to be associated with insecticide metabolism and resistance in many insects. However, information regarding CPR in the bird cherry-oat aphid, Rhopalosiphum padi, is unavailable. In the current study, a full-length cDNA (2,476 bp of CPR (RpCPR encoding 681 amino acids was cloned from R. padi. Nucleotide sequence and deduced amino acid sequence analysis showed that RpCPR exhibits characteristics of classical CPRs and shares high identities with those of other insects, especially with the pea aphid, Acyrthosiphon pisum. The mRNA of RpCPR was expressed at all developmental stages, with the highest expression level found in the second instar and the lowest in adult. Expression levels of RpCPR in isoprocarb-resistant and imidacloprid-resistant strains were 3.74- and 3.53-fold higher, respectively, than that of a susceptible strain. RpCPR expression could also be induced by low concentrations (LC30 of isoprocarb and imidacloprid. Moreover, we sequenced the open reading frame (ORF of RpCPR from 167 field samples collected in 11 geographical populations. Three hundred and thirty-four SNPs were detected, of which, 65 were found in more than two individuals. One hundred and ninety-four missense mutations were present in the amino acid sequence, of which, the P484S mutant had an allele frequency of 35.1%. The present results suggest that RpCPR may play an important role in the P450-mediated insecticide resistance of R. padi to isoprocarb and imidacloprid and possibly other insecticides. Meanwhile, RpCPRmaintains high genetic diversity in natural individuals, which provides the possibility of studying potential correlations between variants and certain special physiological characters.

  18. Genetic Diversity of Chinese and Global Pea (Pisum sativum L.) Collections.

    Science.gov (United States)

    Pea (Pisum sativum L.) is an important food and feed legume grown across many temperate regions of the world, especially from Asia to Europe and North America. The goal of this study was to use 30 informative pea microsatellite markers to compare genetic diversity in a global core from the USDA and ...

  19. The intracellular localization of malate dehydrogenase isoenzymes in Pisum arvense roots

    Directory of Open Access Journals (Sweden)

    Genowefa Kubik-Dorosz

    2014-02-01

    Full Text Available Mitochondria and plastids were isolated from Pisum arvense root cells by sucrose density gradient centrifugation. The individual subcellular fractions so obtained were subjected to isoelectric focusing on cellulose acetate strips. Mitochondria and plastids each contained one NAD -malate dehydrogenase, while three isoenzymes were associated with the supernatant.

  20. Pea (Pisum sativum) Seed Production as an Assay for Reproductive Effects Due to Herbicides.

    Science.gov (United States)

    Even though herbicide drift can affect plant reproduction, current plant testing protocols emphasize effects on vegetative growth. In this study, we determined whether a short–growing season plant can indicate potential effects of herbicides on seed production. Pea (Pisum sativum...

  1. Danish Rhizobium leguminosarum strains nodulating ‘Afghanistan’ pea (Pisum sativum)

    DEFF Research Database (Denmark)

    Jensen, Erik Steen; Sørensen, Lasse Holst; Engvild, Kjeld Christensen

    1986-01-01

    A wild pea (Pisum sativum L.) native to Afghanistan normally known to be resisant to nodulation with European strains of Rhizobium leguminosarum was nodulated early and effectively in field soil in Denmark. Isolates from nodules formed effective nodules abundantly on 'Afghanistan' on reinfection...... pattern with Rhizobium leguminosarum strains isolated from a modern pea variety cultivated in the same field....

  2. The NIa-Pro protein of Turnip mosaic virus improves growth and reproduction of the aphid vector, Myzus persicae (green peach aphid).

    Science.gov (United States)

    Casteel, Clare L; Yang, Chunling; Nanduri, Ananya C; De Jong, Hannah N; Whitham, Steven A; Jander, Georg

    2014-02-01

    Many plant viruses depend on aphids and other phloem-feeding insects for transmission within and among host plants. Thus, viruses may promote their own transmission by manipulating plant physiology to attract aphids and increase aphid reproduction. Consistent with this hypothesis, Myzus persicae (green peach aphids) prefer to settle on Nicotiana benthamiana infected with Turnip mosaic virus (TuMV) and fecundity on virus-infected N. benthamiana and Arabidopsis thaliana (Arabidopsis) is higher than on uninfected controls. TuMV infection suppresses callose deposition, an important plant defense, and increases the amount of free amino acids, the major source of nitrogen for aphids. To investigate the underlying molecular mechanisms of this phenomenon, 10 TuMV genes were over-expressed in plants to determine their effects on aphid reproduction. Production of a single TuMV protein, nuclear inclusion a-protease domain (NIa-Pro), increased M. persicae reproduction on both N. benthamiana and Arabidopsis. Similar to the effects that are observed during TuMV infection, NIa-Pro expression alone increased aphid arrestment, suppressed callose deposition and increased the abundance of free amino acids. Together, these results suggest a function for the TuMV NIa-Pro protein in manipulating the physiology of host plants. By attracting aphid vectors and promoting their reproduction, TuMV may influence plant-aphid interactions to promote its own transmission.

  3. Orange oil effect in the control of fennel aphid

    OpenAIRE

    Ivanildo Cavalcanti de Albuquerque; Luciano de Medeiros Pereira Brito; Carlos Henrique de Brito; Edson Batista Lopes; Jacinto de Luna Batista

    2009-01-01

    In the properties where fennel is grown, in the states of Bahia, Sergipe, Pernambuco and Paraiba, at the Northeast of Brazil, a high rate of usage of pesticides in the crop, aiming to control the aphid Hyadaphis foeniculi. The purpose of this study was to evaluate the effect of orange oil Prev-Am (sodium tetraborohydrate decahydrate), in the control of H. foeniculi aphid of the fennel crop. The trial was conducted in a fennel field located in Lagoa Seca Experimental Station, belonging to the ...

  4. Inventory and assessment of foliar natural enemies of the soybean aphid (Hemiptera: Aphididae) in South Dakota.

    Science.gov (United States)

    Hesler, Louis S

    2014-06-01

    Soybean aphid (Aphis glycines Matsumura) (Hemiptera: Aphididae) is a major pest of soybean in northern production regions of North America, and insecticides have been the primary management approach while alternative methods are developed. Knowledge of arthropod natural enemies and their impact on soybean aphid is critical for developing biological control as a management tool. Soybean is a major field crop in South Dakota, but information about its natural enemies and their impact on soybean aphid is lacking. Thus, this study was conducted in field plots in eastern South Dakota during July and August of 2004 and 2005 to characterize foliar-dwelling, arthropod natural enemies of soybean aphid, and it used exclusion techniques to determine impact of natural enemies and ants (Hymenoptera: Formicidae) on soybean aphid densities. In open field plots, weekly soybean aphid densities reached a plateau of several hundred aphids per plant in 2004, and peaked at roughly 400 aphids per plant in 2005. Despite these densities, a relatively high frequency of aphid-infested plants lacked arthropod natural enemies. Lady beetles (Coleoptera: Coccinellidae) were most abundant, peaking at 90 and 52% of all natural enemies sampled in respective years, and Harmonia axyridis Pallas was the most abundant lady beetle. Green lacewings (Neuroptera: Chrysopidae) were abundant in 2005, due mainly to large numbers of their eggs. Abundances of arachnids and coccinellid larvae correlated with soybean aphid densities each year, and chrysopid egg abundance was correlated with aphid density in 2005. Three-week cage treatments of artificially infested soybean plants in 2004 showed that noncaged plants had fewer soybean aphids than caged plants, but abundance of soybean aphid did not differ among open cages and ones that provided partial or total exclusion of natural enemies. In 2005, plants within open cages had fewer soybean aphids than those within cages that excluded natural enemies, and aphid

  5. High susceptibility of Bt maize to aphids enhances the performance of parasitoids of lepidopteran pests.

    Directory of Open Access Journals (Sweden)

    Cristina A Faria

    Full Text Available Concerns about possible undesired environmental effects of transgenic crops have prompted numerous evaluations of such crops. So-called Bt crops receive particular attention because they carry bacteria-derived genes coding for insecticidal proteins that might negatively affect non-target arthropods. Here we show a remarkable positive effect of Bt maize on the performance of the corn leaf aphid Rhopalosiphum maidis, which in turn enhanced the performance of parasitic wasps that feed on aphid honeydew. Within five out of six pairs that were evaluated, transgenic maize lines were significantly more susceptible to aphids than their near-isogenic equivalents, with the remaining pair being equally susceptible. The aphids feed from the phloem sieve element content and analyses of this sap in selected maize lines revealed marginally, but significantly higher amino acid levels in Bt maize, which might partially explain the observed increased aphid performance. Larger colony densities of aphids on Bt plants resulted in an increased production of honeydew that can be used as food by beneficial insects. Indeed, Cotesia marginiventris, a parasitoid of lepidopteran pests, lived longer and parasitized more pest caterpillars in the presence of aphid-infested Bt maize than in the presence of aphid-infested isogenic maize. Hence, depending on aphid pest thresholds, the observed increased susceptibility of Bt maize to aphids may be either a welcome or an undesirable side effect.

  6. Soybean aphid intrabiotype variability based on colonization of specific soybean genotypes.

    Science.gov (United States)

    Pawlowski, Michelle; Hill, Curtis B; Voegtlin, David J; Hartman, Glen L

    2015-12-01

    The soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is one of the most destructive insect pests on soybeans in the United States. One method for managing this pest is through host plant resistance. Since its arrival in 2000, 4 aphid biotypes have been identified that are able to overcome soybean aphid resistance (Rag) genes. A soybean aphid isolate collected from Moline, Illinois readily colonized soybean plants with the soybean aphid resistance gene Rag2, unlike biotypes 1 and 2, but similar to soybean aphid biotype 3. Two no-choice experiments compared the virulence of the Moline isolate with biotype 3. In both experiments, differences in aphid population counts were not significant (P > 0.05) on soybean genotypes LD08-12957a (Rag2) and LD11-5413a (Rag2), but the aphid counts for the Moline isolate were significantly (P soybean genotypes Dowling (Rag1), LD05-16611 (Rag1), LD11-4576a (Rag1), and PI 567598B (rag1b and rag3). The Moline isolate was a variant of aphid biotype 3, which is the first report showing that soybean aphid isolates classified as the same biotype, based on virulence against specific Rag genes, can differ in aggressiveness or ability to colonize specific host genotypes.

  7. Effects of thiamethoxam seed treatments on soybean aphid (Hemiptera: Aphididae) feeding behavior.

    Science.gov (United States)

    Stamm, M D; Heng-Moss, T M; Baxendale, F P; Reese, J C; Siegfried, B D; Hunt, T E; Gaussoin, R E; Blankenship, E E

    2013-12-01

    Since its discovery in North America in 2000, the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), has rapidly become an important pest of soybean [Glycine max (L.) Merrill], sometimes resulting in significant yield losses. Previous research has documented the toxicity of neonicotinoid seed treatments to soybean aphids, but control under field conditions has been inconsistent. Imidacloprid, a popular neonicotinoid insecticide, has been shown to exhibit antifeedant effects on aphids. Antifeedant activity has not been demonstrated for other neonicotinoids, including thiamethoxam. This research investigated the effects of a thiamethoxam seed treatment on soybean aphid feeding behavior by using electronic penetration graphs (EPG) to visualize stylet penetration behavior. Soybean aphid feeding behavior was assessed for 9 h on thiamethoxam-treated and untreated soybeans (V2 and V4 stages). Because results were inconclusive from initial experiments, a study was conducted to document the effects of thiamethoxam-treated soybeans on soybean aphid survival. The seed treatment was shown to negatively affect aphid survival at 4, 8, and 11 d after aphid introduction. A subsequent EPG study then was designed to document soybean aphid feeding behavior for 15 h, after an initial exposure of 9 h to thiamethoxam-treated soybeans. In this study, the exposed aphids exhibited significant differences in feeding behavior compared with those aphids feeding on untreated soybeans. Soybean aphids on thiamethoxam-treated soybeans spent significantly less time feeding in the sieve element phase, with a greater duration of nonprobing events. These studies suggest soybean aphids are unable to ingest phloem sap, which may be another important element in seed treatment protection.

  8. Differential effects of weather and natural enemies on coexisting aphid populations.

    Science.gov (United States)

    Alyokhin, Andrei; Drummond, Francis A; Sewell, Gary; Storch, Richard H

    2011-06-01

    Study of mechanisms responsible for regulating populations of living organisms is essential for a better comprehension of the structure of biological communities and evolutionary forces in nature. Aphids (Hemiptera: Sternorrhyncha) comprise a large and economically important group of phytophagous insects distributed worldwide. Previous studies determined that density-dependent mechanisms play an important role in regulating their populations. However, only a few of those studies identified specific factors responsible for the observed regulation. Time series data used in this study originated from the untreated control plots that were a part of potato (Solanum tuberosum L.) insecticide trials in northern Maine from 1971 to 2004. The data set contained information on population densities of three potato-colonizing aphid species (buckthorn aphid, Aphis nasturtii; potato aphid, Macrosiphum euphorbiae; and green peach aphid, Myzus persicae) and their natural enemies. We used path analysis to explore effects of weather and natural enemies on the intrinsic growth rates of aphid populations. Weather factors considered in our analyses contributed to the regulation of aphid populations, either directly or through natural enemies. However, direct weather effects were in most cases detectable only at P ≤ 0.10. Potato aphids were negatively affected by both fungal disease and predators, although buckthorn aphids were negatively affected by predators only. Parasitoids did not have a noticeable effect on the growth of any of the three aphid species. Growth of green peach aphid populations was negatively influenced by interspecific interactions with the other two aphid species. Differential population regulation mechanisms detected in the current study might at least partially explain coexistence of three ecologically similar aphid species sharing the same host plant.

  9. Molecular characterization of aphid resistance in black raspberry germplasm

    Science.gov (United States)

    Black raspberry is a minor but lucrative crop with most of the acreage in the U.S. found in Oregon. Rapid decline of plantings results from virus infection vectored by the North American large raspberry aphid and is the most limiting factor for growing black raspberry. Existing cultivars are suscept...

  10. Behavioral evidence for local reduction of aphid-induced resistance

    NARCIS (Netherlands)

    Prado, E.; Tjallingii, W.F.

    2007-01-01

    Twenty-five aphids of three different species, Brevicoryne brassicae L, Myzus persicae Schulzer, and Rhopalosiphum padi L(Hemiptera: Aphididae) were each allowed to infest leaves of a young plant of their respective host plant species for 4 days, except that the oldest expanded leaf (the `systemic¿

  11. Identification and Analysis of Genetic Diversity Structure Within Pisum Genus Based on Microsatellite Markers

    Institute of Scientific and Technical Information of China (English)

    ZONG Xu-xiao; Rebecca Ford; Robert R Redden; GUAN Jian-ping; WANG Shu-min

    2009-01-01

    To assesse the genetic diversity among wild and cultivated accessions of 8 taxonomic groups in 2 species, and 5 subspecies under Pisum genus, and to analyze population structure and their genetic relationships among various groups of taxonomy,the study tried to verify the fitness of traditionally botanical taxonomic system under Pisum genus and to provide essential information for the exploration and utilization of wild relatives of pea genetic resources. 197 Pisum accessions from 62 counties of 5 continents were employed for SSR analysis using 21 polymorphic primer pairs in this study. Except for cultivated field pea Pisum sativum ssp. sativum vat. sativum (94 genotypes), also included were wild relative genotypes that were classified as belonging to P. fulvum, P. sativum ssp.abyssinicum, P. sativum ssp. asiaticum, P. sativum ssp. transcaucasicum, P. sativum ssp. elatius vat. elatius, P. sativum ssp. elatius vat. pumilio and P. sativum ssp.sativum vat. arvense (103 genotypes). The PCA analyses and 3-dimension PCA graphs were conducted and drawn by NTSYSpe 2.2d statistical package. Nei78 genetic distances among groups of genetic resources were calculated, and cluster analysis using UPGMA method was carried out by using Popgene V1.32 statistical package, the dendrogram was drawn by MEGA3.1 statistical package. Allelie statistics were carried out by Popgene V1.32. The significance test between groups of genotypes was carried out by Fstat V2.9.3.2 statistical package. 104 polymorphic bands were amplified using 21 SSR primer pairs with unambiguous unique polymorphic bands. 4.95 alleles were detected by each SSR primer pair in average, of which 65.56% were effective alleles for diversity. PSAD270, PSAC58, PSAA18, PSAC75, PSAA175 and PSAB72 were the most effective SSR pairs. SSR alleles were uniformly distributed among botanical taxon units under Pisum genus, but significant difference appeared in most pairwise comparisons for genetic diversity between taxon unit based

  12. The genetic diversity and evolution of field pea (Pisum studied by high throughput retrotransposon based insertion polymorphism (RBIP marker analysis

    Directory of Open Access Journals (Sweden)

    Smýkal Petr

    2010-02-01

    Full Text Available Abstract Background The genetic diversity of crop species is the result of natural selection on the wild progenitor and human intervention by ancient and modern farmers and breeders. The genomes of modern cultivars, old cultivated landraces, ecotypes and wild relatives reflect the effects of these forces and provide insights into germplasm structural diversity, the geographical dimension to species diversity and the process of domestication of wild organisms. This issue is also of great practical importance for crop improvement because wild germplasm represents a rich potential source of useful under-exploited alleles or allele combinations. The aim of the present study was to analyse a major Pisum germplasm collection to gain a broad understanding of the diversity and evolution of Pisum and provide a new rational framework for designing germplasm core collections of the genus. Results 3020 Pisum germplasm samples from the John Innes Pisum germplasm collection were genotyped for 45 retrotransposon based insertion polymorphism (RBIP markers by the Tagged Array Marker (TAM method. The data set was stored in a purpose-built Germinate relational database and analysed by both principal coordinate analysis and a nested application of the Structure program which yielded substantially similar but complementary views of the diversity of the genus Pisum. Structure revealed three Groups (1-3 corresponding approximately to landrace, cultivar and wild Pisum respectively, which were resolved by nested Structure analysis into 14 Sub-Groups, many of which correlate with taxonomic sub-divisions of Pisum, domestication related phenotypic traits and/or restricted geographical locations. Genetic distances calculated between these Sub-Groups are broadly supported by principal coordinate analysis and these, together with the trait and geographical data, were used to infer a detailed model for the domestication of Pisum. Conclusions These data provide a clear picture

  13. INFLUENCE OF NOSTOC VAUCHER EX BORNET ET FLAHAULT STRAINS ON GROWTH AND DEVELOPMENT OF PISUM SATIVUM L.

    Directory of Open Access Journals (Sweden)

    Ye. I. Maltsev

    2015-12-01

    Full Text Available We investigated the positive impact of cultures cyanobacteria genus Nostoc Vaucher ex Bornet et Flahault on growth and development of higher plants as an example Pisum sativum L. All the Nostoc species have a positive effect on the viability, germination energy, and biometric characteristics of Pisum sativum. The greatest positive influence was registered for N. entophytum Born. et. Flah. and N. linckia (Roth Bornetet Flahault f. linckia. Keywords: Nostoc, seed pelleting, viability, germination energy, biomass.

  14. INFLUENCE OF NOSTOC VAUCHER EX BORNET ET FLAHAULT STRAINS ON GROWTH AND DEVELOPMENT OF PISUM SATIVUM L.

    Directory of Open Access Journals (Sweden)

    Maltsev Ye. I.

    2015-12-01

    Full Text Available We investigated the positive impact of cultures cyanobacteria genus Nostoc Vaucher ex Bornet et Flahault on growth and development of higher plants as an example Pisum sativum L. All the Nostoc species have a positive effect on the viability, germination energy, and biometric characteristics of Pisum sativum. The greatest positive influence was registered for N. entophytum Born. et. Flah. and N. linckia (Roth Bornetet Flahault f. linckia.

  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. Differential reactions of soybean isolines with combinations of aphid resistance genes Rag1, Rag2, and Rag3 to four soybean aphid biotypes

    Science.gov (United States)

    With the discovery of the soybean aphid (Aphis glycines Matsumura) as a devastating insect pest of soybean (Glycine max (L.) Merr.) in the United States, host resistance was recognized as an important management option. However, the identification of soybean aphid isolates exhibiting strong virulenc...

  17. DNA barcoding and the associated PhylAphidB@se website for the identification of European aphids (Insecta: Hemiptera: Aphididae.

    Directory of Open Access Journals (Sweden)

    Armelle Coeur d'Acier

    Full Text Available Aphids constitute a diverse group of plant-feeding insects and are among the most important crop pests in temperate regions. Their morphological identification is time-consuming and requires specific knowledge, training and skills that may take years to acquire. We assessed the advantages and limits of DNA barcoding with the standard COI barcode fragment for the identification of European aphids. We constructed a large reference dataset of barcodes from 1020 specimens belonging to 274 species and 87 genera sampled throughout Europe and set up a database-driven website allowing species identification from query sequences.In this unbiased sampling of the taxonomic diversity of European aphids, intraspecific divergence ranged from 0.0% to 3.9%, with a mean value of 0.29%, whereas mean congeneric divergence was 6.4%, ranging from 0.0% to 15%. Neighbor-joining analysis generated a tree in which most species clustered in distinct genetic units. Most of the species with undifferentiated or overlapping barcodes belonged to the genus Aphis or, to a lesser extent, the genera Brachycaudus, Dysaphis and Macrosiphum. The taxa involved were always morphologically similar or closely related and belonged to species groups known to present taxonomic difficulties.These data confirm that COI barcoding is a useful identification tool for aphids. Barcode identification is straightforward and reliable for 80% of species, including some difficult to distinguish on the basis of morphological characters alone. Unsurprisingly, barcodes often failed to distinguish between species from groups for which classical taxonomy has also reached its limits, leading to endless revisions and discussions about species and subspecies definitions. In such cases, the development of an effective procedure for the accurate identification of aphid specimens continues to pose a difficult challenge.

  18. Impacts of thiamethoxam seed treatment and host plant resistance on the soybean aphid fungal pathogen, Pandora neoaphidis.

    Science.gov (United States)

    Koch, Karrie A; Ragsdale, David W

    2011-12-01

    Since the introduction of soybean aphid, Aphis glycines Matsumura, from Asia, insecticide use in soybean has increased substantially in the north central United States. Insecticide seed treatments and aphid resistant soybean varieties are management tactics that may reduce reliance on foliar applications of broad-spectrum insecticides. Exploring potential nontarget impacts of these technologies will be an important step in incorporating them into aphid management programs. We investigated impacts of thiamethoxam seed treatment and Rag1 aphid resistant soybean on a fungal pathogen of soybean aphid, Pandora neoaphidis (Remaudière & Hennebert) Humber, via open plot and cage studies. We found that although thiamethoxam seed treatment did significantly lower aphid pressure in open plots compared with an untreated control, this reduction in aphid density translated into nonsignificant decreases in fungal disease prevalence in aphids. Furthermore, when aphid densities were approximately equal in seed treated and untreated soybean, no impact on aphid fungal disease was observed. In open plots, Rag1 resistant soybean experienced lower aphid pressure and aphid disease prevalence compared with a nonresistant isoline. However, in cages when aphid densities were equivalent in both resistant and susceptible soybean, resistance had no impact on aphid disease prevalence. The addition of thiamethoxam seed treatment to resistant soybean yielded aphid densities and aphid disease prevalence similar to untreated, resistant soybean. These studies provide evidence that thiamethoxam seed treatments and Rag1 resistance can impact P. neoaphidis via decreased aphid densities; however, this impact is minimal, implying use of seed treatments and host plant resistance are compatible with P. neoaphidis.

  19. Changes in the Russian Wheat Aphid (Hemiptera: Aphididae) Biotype Complex in South Africa.

    Science.gov (United States)

    Jankielsohn, Astrid

    2016-04-01

    Russian wheat aphid Diuraphis noxia (Kurdjumov) has spread from its native area in central Asia to all the major wheat-producing countries in the world to become an international wheat pest. Because the Russian wheat aphid is a serious threat to the wheat industry in South Africa, it is important to investigate the key factors involved in the distribution of Russian wheat aphid biotypes and in the changes of the Russian wheat aphid biotype complex in South Africa. There are currently four known Russian wheat aphid biotypes occurring in South Africa. Russian wheat aphid samples were collected from 2011 to 2014 during the wheat-growing season in spring and summer and these samples were screened to determine the biotype status. RWASA1 occurred predominantly in the Western Cape, while RWASA2 and RWASA3 occurred predominantly in the Eastern Free State. Following the first record of RWASA4 in 2011, this biotype was restricted to the Eastern Free State. The surveys suggest that the Russian wheat aphid bioype complex was more diverse in the Eastern Free State than in the other wheat production areas. There was also a shift in Russian wheat aphid biotype composition over time. The Russian wheat aphid biotype complex is dynamic, influenced by environmental factors such as host plants, altitude, and climate, and it can change and diversify over time causing fluctuation in populations over sites and years. This dynamic nature of the Russian wheat aphid will continue to challenge the development of Russian wheat aphid-resistant wheat cultivars in South Africa, and the continued monitoring of the biotypic and genetic structure, to determine genetic relatedness and variation in different biotypes, of Russian wheat aphid populations is important for protecting wheat.

  20. Aphids (Homoptera, Aphidodea inhabiting the trees Crataegus x media Bechst. in the urban green area. Part II. Domination and frequency of aphids, their enemies and the damage caused by aphids

    Directory of Open Access Journals (Sweden)

    Aneta Sławińska

    2013-12-01

    Full Text Available The studies were conducted in Lublin in the years 1999-2001 in two sites (street and park ones on the trees Crataegus x inedia Bechst. The purpose was to determine the domination and frequency of particular aphid species, their effect on the decorative character of plants as well as the occurrence of the aphidophagous in aphid colonies. It was found out that A. pomi was the dominating species in both sites. The decorative character of the studied trees was lowered by aphids A. pomi and aphids from the genus Dysaphis. Aphids from the genus Dysaphis also caused changes in the chemical composition of the injured plant parts. The presence of predatory arthropods was observed in aphid colonies occurring on hawthorn. The most numerous of these were the larvae of Syrphidae and Coccinellidae. The culture of parasitized aphids gave numerous flights of parasitoids and hyperparasitoids. Greater number of both predators and parasitoids of I and II grades were observed in the street site as compared to the park site.

  1. EFFICACY OF IMIDACLOPRID (CONFIDOR 200 SL AGAINST APHIDS INFESTING WHEAT CROP

    Directory of Open Access Journals (Sweden)

    N Joshi

    2010-02-01

    Full Text Available Imidacloprid (Confidor 200 SL was evaluated either alone or with a fungicide (Tilt 0.01% against wheat aphids. There were seven different treatments, including an untreated control. All the treatments were replicated three times in a similar field environment. Population of wheat aphids was recorded on randomly selected five plants in each plot at different intervals, both before and after the spraying. Confidor 200 SL @ 400 ml/ha treatment was found most effective against wheat aphids. However, mixing of Confidor 200 SL @ 100 ml/ha with Tilt @ 0.01 %, was found significantly least effective for wheat aphids control.

  2. Modification of non-vector aphid feeding behavior on virus-infected host plant.

    Science.gov (United States)

    Hu, Zuqing; Zhao, Huiyan; Thieme, Thomas

    2013-01-01

    Virus-infected host plants can have positive, neutral or negative effects on vector aphids. Even though the proportion of non-vector aphids associated with a plant far exceeds that of vector species, little is known about the effect of virus-infected plants on non-vector aphids. In the present study, the English grain aphid Sitobion avenae (Fabricius) (Hemiptera: Aphididae), a non-vector of Wheat dwarf virus (WDV) and Cereal yellow dwarf virus-RPV (CYDV-RPV), was monitored on, virus-infected, virus-free and leafhopper/aphid-infested, and virus- and insect-free (control) barley, Hordeum vulgare L. (Poales: Poaceae), plants. Electrical penetration graph recordings were performed. Compared with the control plants, S. avenae on infected plants exhibited reduced non-probing and pathway phase, and increased phloem sap ingestion phase, and more aphids reached sustained phloem ingestion. However, the electrical penetration graph parameters described above showed no significant differences in aphid feeding behavior on virus-free and vector pre-infested plants and the control barley plants during S. avenae feeding. The results suggest that WDV/CYDV-RPV-infected host plants positively affected the feeding behavior of the non-vector aphid S. avenae. Based on these results, the reasons and trends among the virus-infected host plants' effects on the feeding behavior of non-vector aphids are discussed.

  3. Modification of Non-Vector Aphid Feeding Behavior on Virus-Infected Host Plant

    OpenAIRE

    Hu, Zuqing; Zhao, Huiyan; Thieme, Thomas

    2013-01-01

    Virus-infected host plants can have positive, neutral or negative effects on vector aphids. Even though the proportion of non-vector aphids associated with a plant far exceeds that of vector species, little is known about the effect of virus-infected plants on non-vector aphids. In the present study, the English grain aphid Sitobion avenae (Fabricius) (Hemiptera: Aphididae), a non-vector of Wheat dwarf virus (WDV) and Cereal yellow dwarf virus-RPV (CYDV-RPV), was monitored on, virus-infected,...

  4. A Secreted MIF Cytokine Enables Aphid Feeding and Represses Plant Immune Responses.

    Science.gov (United States)

    Naessens, Elodie; Dubreuil, Géraldine; Giordanengo, Philippe; Baron, Olga Lucia; Minet-Kebdani, Naïma; Keller, Harald; Coustau, Christine

    2015-07-20

    Aphids attack virtually all plant species and cause serious crop damages in agriculture. Despite their dramatic impact on food production, little is known about the molecular processes that allow aphids to exploit their host plants. To date, few aphid salivary proteins have been identified that are essential for aphid feeding, and their nature and function remain largely unknown. Here, we show that a macrophage migration inhibitory factor (MIF) is secreted in aphid saliva. In vertebrates, MIFs are important pro-inflammatory cytokines regulating immune responses. MIF proteins are also secreted by parasites of vertebrates, including nematodes, ticks, and protozoa, and participate in the modulation of host immune responses. The finding that a plant parasite secretes a MIF protein prompted us to question the role of the cytokine in the plant-aphid interaction. We show here that expression of MIF genes is crucial for aphid survival, fecundity, and feeding on a host plant. The ectopic expression of aphid MIFs in leaf tissues inhibits major plant immune responses, such as the expression of defense-related genes, callose deposition, and hypersensitive cell death. Functional complementation analyses in vivo allowed demonstrating that MIF1 is the member of the MIF protein family that allows aphids to exploit their host plants. To our knowledge, this is the first report of a cytokine that is secreted by a parasite to modulate plant immune responses. Our findings suggest a so-far unsuspected conservation of infection strategies among parasites of animal and plant species.

  5. THE ROLE OF BACTERIAL SYMBIONTS IN AMINO ACID COMPOSITION OF BLACK BEAN APHIDS

    Institute of Scientific and Technical Information of China (English)

    MingGan; De-ChengDing; Xue-xiaMiao

    2003-01-01

    To evaluate the role of bacterial symbionts ( Buchnera spp. ) in the black bean aphids ( Aphis craccivora Koch), the aphids were treated with the antibiotic, rifampicin, to eliminate their intracellular symbiotic bacteria. Analysis of protein and amino acid concentration in 7-day-old of aposymbiotic aphids showed that the total protein content per mg fresh weight was significantly reduced by 29 %, but free amino acid titers were increased by 17% . The ratio of the essential amino acids was in general only around 20% essential amino acids in phloem sap of broad bean, whereas it was 44% and 37% in symbiotic and aposymbiotic aphids, respectively,suggesting that the composition of the free amino acids was unbalanced. For example, the essential amino acid,threonine represented 21. 6% of essential amino acids in symbiotic aphids, but it was only 16.7% in aposymbiotic aphids. Likewise, two nonessential amino acids, tyrosine and serine, represented 8.9% and 5.6% of total amino acids in symbiontic aphids, respectively, but they enhanced to 21.1% and 13.6% in aposymbiotic aphids. It seems likely that the elevated free amino acid concentration in aposymbiotic aphids was caused by the limited protein anabolism as the result of the unbalanced amino acid composition.

  6. New data on aphid fauna (Hemiptera, Aphididae) in Algeria

    Science.gov (United States)

    Laamari, Malik; d’Acier, Armelle Coeur; Jousselin, Emmanuelle

    2013-01-01

    Abstract A survey of aphids was carried out during the period 2008-2011 in different regions of Algeria by collecting and identifying aphids and their host plants. Aphids were collected from 46 host plants. Forty-six species were reported including thirty-six species which were recorded for the first time in this country and thirty species which were recorded for the first time in the Maghreb (North Africa). This study extends the number of known Algerian aphid to 156 species. PMID:24039520

  7. Nitrogen and phosphorus compounds in the aleurone grains of Iris pseudoacorus endosperm and Pisum sativum cotyledons

    OpenAIRE

    Ligia Konopska

    2015-01-01

    Aleurone grains from Iris pseudoacorus endosperm and Pisum sativum cotyledons were isolated partly according to Tombs's method (1967). Nitrogen compounds content was determined in them by Kjeldahl's micromethod, and in the particular fractions after Thiman and Laloraya (1960). Mainly protein N was detected in the aleurone grains, constituting 14.8 and 15.2 per cent of the dry mass of pea and Iris seeds, respectively. Moreover, phosphorus compounds were fractionated according to Holden and Pir...

  8. NDVI to Detect Sugarcane Aphid Injury to Grain Sorghum.

    Science.gov (United States)

    Elliott, N C; Backoulou, G F; Brewer, M J; Giles, K L

    2015-06-01

    Multispectral remote sensing has potential to provide quick and inexpensive information on sugarcane aphid, Melanaphis sacchari (Zehntner), pest status in sorghum fields. We describe a study conducted to determine if injury caused by sugarcane aphid to sorghum plants in fields of grain sorghum could be detected using multispectral remote sensing from a fixed wing aircraft. A study was conducted in commercial grain sorghum fields in the Texas Gulf Coast region in June 2014. Twenty-six commercial grain sorghum fields were selected and rated for the level of injury to sorghum plants in the field caused by sugarcane aphid. Plant growth stage ranged from 5.0 (watery ripe) to 7.0 (hard dough) among fields; and plant injury rating from sugarcane aphid ranged from 1.0 (little or no injury) to 4.0 (>40% of plants displaying injury) among fields. The normalized differenced vegetation index (NDVI) is calculated from light reflectance in the red and near-infrared wavelength bands in multispectral imagery and is a common index of plant stress. High NDVI indicates low levels of stress and low NDVI indicates high stress. NDVI ranged from -0.07 to 0.26 among fields. The correlation between NDVI and plant injury rating was negative and significant, as was the correlation between NDVI and plant growth stage. The negative correlation of NDVI with injury rating indicated that plant stress increased with increasing plant injury. Reduced NDVI with increasing plant growth probably resulted from reduced photosynthetic activity in more mature plants. The correlation between plant injury rating and plant growth stage was positive and significant indicating that plant injury from sugarcane aphid increased as plants matured. The partial correlation of NDVI with plant injury rating was negative and significant indicating that NDVI decreased with increasing plant injury after adjusting for its association with plant growth stage. We demonstrated that remotely sensed imagery acquired from grain

  9. Coexistence of three specialist aphids on common milkweed, Asclepias syriaca.

    Science.gov (United States)

    Smith, R A; Mooney, K A; Agrawal, A A

    2008-08-01

    Coexistence of host-specific herbivores on plants is believed to be governed by interspecific interactions, but few empirical studies have systematically unraveled these dynamics. We investigated the role of several factors in promoting coexistence among the aphids Aphis nerii, Aphis asclepiadis, and Myzocallis asclepiadis that all specialize on common milkweed (Asclepias syriaca). Competitive exclusion is thought to occur when interspecific competition is stronger than intraspecific competition. Consequently, we investigated whether predators, mutualists, or resource quality affected the strength of intra- vs. interspecific competition among aphids in factorial manipulations of competition with exposure to predation, ants, and variable plant genotypes in three separate experiments. In the predation x competition experiment, predators reduced aphid per capita growth by 66%, but the strength of intra- and interspecific competition did not depend on predators. In the ants x competition experiment, ants reduced per capita growth of A. nerii and M. asclepiadis (neither of which were mutualists with ants) by approximately one-half. In so doing, ants ameliorated the negative effects of these competitors on ant-tended A. asclepiadis by two-thirds, representing a novel benefit of ant-aphid mutualism. Nevertheless, ants alone did not explain the persistence of competitively inferior A. asclepiadis as, even in the presence of ants, interspecific competition remained stronger than intraspecific competition. In the plant genotype x competition experiment, both A. asclepiadis and M. asclepiadis were competitively inferior to A. nerii, with the strength of interspecific competition exceeding that of intraspecific competition by 83% and 23%, respectively. Yet these effects differed among milkweed genotypes, and there were one or more plant genotypes for each aphid species where coexistence was predicted. A synthesis of our results shows that predators play little or no role in

  10. Proteomic analysis of secreted saliva from Russian wheat aphid (Diuraphis noxia Kurd.) biotypes that differ in virulence to wheat

    Science.gov (United States)

    Diuraphis noxia, Russian Wheat Aphid (RWA), biotypes are classified by their differential virulence to wheat varieties containing resistance genes. RWA salivary proteins, unlike those of most aphid species, cause foliar damage and physiological alterations in plants. A comparative proteomic analys...

  11. The Process of Aphid Egg-Laying and the Little Known Role of the Coccinellidae in Aphid Egg Destruction in Poland – Preliminary Results

    Directory of Open Access Journals (Sweden)

    Lubiarz Magdalena

    2014-07-01

    Full Text Available No detailed studies have been conducted in Poland with regard to aphid eggs or egg survival in particular. So far, no studies have been conducted concerning the role of ladybird beetles in reducing the number of aphid eggs in spring, before the development of leaves, and in autumn, after the leaves have been shed. At these times, other developmental stages of aphids are unavailable as food for the ladybirds. The paper presents the preliminary results of a three-year study on the process of aphid egg-laying (especially Chaetosiphon tetrarhodum, Macrosiphum rosae, Metopolophium dirhodum, and Maculolachnus submacula. The paper also deals with the little known role of ladybirds in aphid egg destruction. Research was conducted in Otrębusy (Western Mazovia, Poland, in the years 2008-2010, on the rugosa rose and on the dog rose. In the years 2011-2013, in Otrębusy, the occurrence of M. submacula was also observed on the ornamental grandiflora rose. Furthermore, in the years 2003-2004, observations were conducted on the pedunculate oak in Polesie National Park and in the town of Puławy (Lublin Region, Poland. The observations which took place in Puławy focused on egglaying of aphids representing the genera Phylloxera and Lachnus. The study investigated aphid oviposition sites. Data was collected on the number of aphid eggs noted on the studied plants. The study also showed, that sometimes winter eggs of aphids could provide nutrition for ladybirds. This was especially true in autumn when ladybird beetles were preparing for hibernation.

  12. Masculinization of the x chromosome in the pea aphid.

    Directory of Open Access Journals (Sweden)

    Julie Jaquiéry

    Full Text Available Evolutionary theory predicts that sexually antagonistic mutations accumulate differentially on the X chromosome and autosomes in species with an XY sex-determination system, with effects (masculinization or feminization of the X depending on the dominance of mutations. Organisms with alternative modes of inheritance of sex chromosomes offer interesting opportunities for studying sexual conflicts and their resolution, because expectations for the preferred genomic location of sexually antagonistic alleles may differ from standard systems. Aphids display an XX/X0 system and combine an unusual inheritance of the X chromosome with the alternation of sexual and asexual reproduction. In this study, we first investigated theoretically the accumulation of sexually antagonistic mutations on the aphid X chromosome. Our results show that i the X is always more favourable to the spread of male-beneficial alleles than autosomes, and should thus be enriched in sexually antagonistic alleles beneficial for males, ii sexually antagonistic mutations beneficial for asexual females accumulate preferentially on autosomes, iii in contrast to predictions for standard systems, these qualitative results are not affected by the dominance of mutations. Under the assumption that sex-biased gene expression evolves to solve conflicts raised by the spread of sexually antagonistic alleles, one expects that male-biased genes should be enriched on the X while asexual female-biased genes should be enriched on autosomes. Using gene expression data (RNA-Seq in males, sexual females and asexual females of the pea aphid, we confirm these theoretical predictions. Although other mechanisms than the resolution of sexual antagonism may lead to sex-biased gene expression, we argue that they could hardly explain the observed difference between X and autosomes. On top of reporting a strong masculinization of the aphid X chromosome, our study highlights the relevance of organisms displaying

  13. Host Selection of the giant willow aphid (Tuberolachnus salignus)

    OpenAIRE

    Aradottir, G; Karp, A.; Hanley, SJ; Woodcock, C; Dewhirst, S.; Collins, CM; Leather, SR; Harrington, R.

    2009-01-01

    The giant willow aphid [Tuberolachnus salignus (Gmelin)] has recently become noteworthy as a potential pest species due to the increased uptake of willow, its host-plant, for use in growing biomass for energy production. In this paper we describe host selection studies of T. salignus on short rotation coppice (SRC) willow varieties in laboratory bioassays and field experiments. In laboratory olfactometry tests, T. salignus was significantly attracted to certain SRC willow varieties, but not t...

  14. Orange oil effect in the control of fennel aphid

    Directory of Open Access Journals (Sweden)

    Ivanildo Cavalcanti de Albuquerque

    2009-08-01

    Full Text Available In the properties where fennel is grown, in the states of Bahia, Sergipe, Pernambuco and Paraiba, at the Northeast of Brazil, a high rate of usage of pesticides in the crop, aiming to control the aphid Hyadaphis foeniculi. The purpose of this study was to evaluate the effect of orange oil Prev-Am (sodium tetraborohydrate decahydrate, in the control of H. foeniculi aphid of the fennel crop. The trial was conducted in a fennel field located in Lagoa Seca Experimental Station, belonging to the EMEPA-PB. Forty-eight hours after the product has been sprayed, one flower of the umbel was collected and removed her aphids, which were placed in a "petri" plate from 9cm in diameter. As a following step, the insects were counted as part of two groups, considering the number of insects dead and alive, being tabulated for later analysis. The data were subjected to analysis of variance, using the experimental design of randomized blocks composed of six treatments (doses of 0.3, 0.4, 0.5, 0.6, 0.7% of orange oil (Prev-am and pure water as check, with five repetitions. The data were submitted to the regression analysis. The orange oil (Prev-am controls effectively H. foeniculi at the concentration of 0.3%, increasing the control up to concentrations of 0.6 and 0.7%. The product does not kill ladybugs (Cycloneda sanguinea and can be used in programs for integrated pest management.Keywords: Foeniculum vulgare, aphid, vegetable oil, ladybug, umbel.

  15. Estimating ancestral geographical distributions: a Gondwanan origin for aphid parasitoids?

    OpenAIRE

    Belshaw, R; Dowton, M; Quicke, D L; Austin, A. D.

    2000-01-01

    We tested the published hypothesis of a Gondwanan origin for the overwhelmingly northern hemisphere aphid parasitoids (Aphidiinae) as follows: (i) finding their sister group by a phylogenetic analysis of the entire Braconidae (Insecta: Hymenopterai using sequence data from approximately 500 bp fragments of both the nuclear 28S (D2 region) and mitochondrial 16S rDNA genes, (ii) using this sister-group relationship and the more informative 28S D2 gene to estimate the phylogeny of the Aphidiinae...

  16. Aphid Infestation Increases Fusarium langsethiae and T-2 and HT-2 Mycotoxins in Wheat.

    Science.gov (United States)

    Drakulic, Jassy; Ajigboye, Olubukola; Swarup, Ranjan; Bruce, Toby; Ray, Rumiana V

    2016-11-15

    Fusarium langsethiae is a fungal pathogen of cereal crops that is an increasing problem in northern Europe, but much of its epidemiology is poorly understood. The species produces the mycotoxins T-2 and HT-2, which are highly toxic. It was hypothesized that grain aphids, Sitobion avenae, may transmit F. langsethiae inoculum between wheat plants, and a series of transmission experiments and volatile chemical analyses was performed to test this. Manual translocation of aphids from inoculated to uninfected hosts resulted in pathogen DNA accumulation in hosts. However, the free movement of wingless aphids from infected to healthy plants did not. The addition of winged aphids reared on F. langsethiae-inoculated wheat seedlings to wheat plants also did not achieve successful pathogen transfer. While our data suggested that aphid transmission of the pathogen was not very efficient, we observed an increase in disease when aphids were present. After seedling inoculation, an increase in pathogen DNA accumulation in seedling leaves was observed upon treatment with aphids. Furthermore, the presence of aphids on wheat plants with F. langsethiae-inoculated ears not only led to a rise in the amount of F. langsethiae DNA in infected grain but also to an increase in the concentrations of T-2 and HT-2 toxins, with more than 3-fold higher toxin levels than diseased plants without aphids. This work highlights that aphids increase the susceptibility of wheat host plants to F. langsethiae and that aphid infestation is a risk factor for accumulating increased levels of T-2 and HT-2 in wheat products.

  17. Soybean aphid (Hemiptera: Aphididae) response to soybean plant defense: stress levels, tradeoffs, and cross-virulence.

    Science.gov (United States)

    Enders, Laramy; Bickel, Ryan; Brisson, Jennifer; Heng-Moss, Tiffany; Siegfried, Blair; Zera, Anthony; Miller, Nick

    2014-02-01

    A variety of management methods to control the soybean aphid (Aphis glycines Matsumura) have been investigated since its invasion into North America in 2000, among them plant resistance has emerged as a viable option for reducing aphid damage to soybeans and preventing outbreaks. Plant resistance methods often use natural soybean plant defenses that impose stress on aphids by reducing fitness and altering behavior. Research efforts have heavily focused on identification and development of aphid resistant soybean varieties, leaving much unknown about soybean aphid response to stressful host plant defenses. In this study, we aimed to 1) evaluate lifetime fitness consequences and phenotypic variation in response to host plant-induced stress and 2) investigate whether trade-offs involving fitness costs and/or cross-virulence to multiple antibiotic soybean varieties exists. We compared aphid survival and reproduction during and after a short period of exposure to soybeans with the Rag2 resistance gene and measured aphid clonal variation in response to Rag2 soybeans. In addition, we measured the performance of Rag2 virulent and avirulent aphids on five soybean varieties with various forms of antibiotic resistance. Our results indicate that plant defenses impose high levels of stress and have long-term fitness consequences, even after aphids are removed from resistant plants. We identified one aphid clone that was able to colonize Rag2 among the seven clones tested, suggesting that virulent genotypes may be prevalent in natural populations. Finally, although we did not find evidence of cross-virulence to multiple antibiotic soybean varieties, our results suggest independent mechanisms of aphid virulence to Rag1 and Rag2 that may involve fitness costs.

  18. Maintaining genetic diversity and population panmixia through dispersal and not gene flow in a Holocyclic heteroecious aphid species

    Science.gov (United States)

    Heteroecious holocyclic aphids alternate between sexual and asexual reproduction on primary and secondary hosts, respectively. Most of these aphids are generalists, but the aphid specialist Aphis glycines survives only on the primary host buckthorn (Rhamnus spp.) and the secondary host soybean (Gly...

  19. 77 FR 46373 - Field Release of Aphelinus glycinis for the Biological Control of the Soybean Aphid in the...

    Science.gov (United States)

    2012-08-03

    ... the Biological Control of the Soybean Aphid in the Continental United States; Availability of an... release of Aphelinus glycinis for the biological control of the soybean aphid, Aphis glycines, in the...-2323. SUPPLEMENTARY INFORMATION: Background The soybean aphid, Aphis glycinis, which is native to...

  20. Impact of aphid alarm pheromone release on virus transmission efficiency: When pest control strategy could induce higher virus dispersion.

    Science.gov (United States)

    Lin, Fang-Jing; Bosquée, Emilie; Liu, Ying-Jie; Chen, Ju-Lian; Yong, Liu; Francis, Frédéric

    2016-09-01

    Aphids cause serious damages to crops not only by tacking sap but also by transmitting numerous viruses. To develop biological control, the aphid alarm pheromone, namely E-β-farnesene (EβF), has been demonstrated to be efficient to repel aphids and as attract beneficials, making it a potential tool to control aphid pests. Considering aphids also as virus vectors, changes of their behavior could also interfere with the virus acquisition and transmission process. Here, a combination of two aphid species and two potato virus models were selected to test the influence of EβF release on aphid and virus dispersion under laboratory conditions. EβF release was found to significantly decrease the population of Myzus persicae and Macrosiphum euphorbiae around the infochemical releaser but simultaneously also increasing the dispersal of Potato Virus Y (PVY). At the opposite, no significant difference for Potato Leaf Roll Virus (PLRV) transmission efficiency was observed with similar aphid alarm pheromone releases for none of the aphid species. These results provide some support to carefully consider infochemical releasers not only for push-pull strategy and pest control but also to include viral disease in a the plant protection to aphids as they are also efficient virus vectors. Impact of aphid kinds and transmission mechanisms will be discussed according to the large variation found between persistent and non persistent potato viruses and interactions with aphids and related infochemicals.

  1. Aphid infestation affecting the biogeochemistry of European beech saplings

    Science.gov (United States)

    Michalzik, B.; Levia, D. F., Jr.; Bischoff, S.; Näthe, K.

    2014-12-01

    Mass outbreaks of herbivore insects are known to perturb the functional properties of forests. However, it is less clear how endemic to moderate aboveground herbivory affects the vertical flow of nutrients from tree canopies to the soil. Here, we report on the effects of low to moderate infestation levels of the woolly beech aphid (Phyllaphis fagi L.) on the nutrient dynamics and hydrology of European beech (Fagus sylvatica L.). In a potted sapling experiment, we followed the vertical dynamics of nutrients via throughfall (TF), stemflow (SF) and litter leachates (LL) collected over ten weeks underneath infested and uninfested control trees. Aphid infestation amplifies the fluxes of K+, Mn2+ and particulate nitrogen (0.45μm factor of up to 200 compared to TF.Imaging of leaf surfaces by scanning electron microscopy exhibited notable differences of the surface morphology and microbiology of control, lightly infested, and heavily infested leaves. This observation might point to an aphid-mediated alteration of the phyllosphere ecology triggering the microbial uptake of NH4-N and SO4-S and its transformation to particulate N by magnified biomass growth of the phyllosphere microflora, consequently changing the chemical partitioning and temporal availability of nitrogen.

  2. Wild Solanum resistance to aphids: antixenosis or antibiosis?

    Science.gov (United States)

    Le Roux, Vincent; Dugravot, Sébastien; Campan, Erick; Dubois, Françoise; Vincent, Charles; Giordanengo, Philippe

    2008-04-01

    The type (antixenosis or antibiosis) of resistance against the aphids Myzus persicae (Sulzer) and Macrosiphum euphorbiae (Thomas) was characterized for the wild tuber-bearing potatoes, Solanum chomatophilum Bitter and Solanum stoloniferum Schltdl. & Bouché through behavioral (olfactometry and electrical penetration graph) and physiological studies. In dual-choice assays, only S. stoloniferum exerted attraction to M. euphorbiae. This ruled out the possibility that plant volatiles of S. chomatophilum and S. stoloniferum may contribute to the high resistance expressed. In electrical penetration graph experiments, aphids feeding on S. stoloniferum showed increased salivation phases, whereas phloem ingestion was drastically reduced for both aphid species. Because reaching phloem elements was not delayed in both species, the resistance mechanism was phloem-located. The antixenosis exhibited by S. stoloniferum was similar on young and mature leaves. S. chomatophilum also showed phloem-located antixenosis against M. persicae. In contrast, M. euphorbiae had no difficulty to reach S. chomatophilum phloem tissues and to ingest sap. S. chomatophilum resistance against M. euphorbiae was antibiosis and only expressed in mature leaves, where a complete nymphal mortality was observed.

  3. Plant-derived differences in the composition of aphid honeydew and their effects on colonies of aphid-tending ants

    OpenAIRE

    Pringle, Elizabeth G.; Novo, Alexandria; Ableson, Ian; Barbehenn, Raymond V; Vannette, Rachel L.

    2014-01-01

    In plant–ant–hemipteran interactions, ants visit plants to consume the honeydew produced by phloem-feeding hemipterans. If genetically based differences in plant phloem chemistry change the chemical composition of hemipteran honeydew, then the plant's genetic constitution could have indirect effects on ants via the hemipterans. If such effects change ant behavior, they could feed back to affect the plant itself. We compared the chemical composition of honeydews produced by Aphis nerii aphid c...

  4. UAS-derived crop height and NDVI metrics for sorghum yield and aphid stress assessment

    Science.gov (United States)

    A small, fixed-wing UAS was used to survey a replicated small plot field experiment designed to estimate sorghum damage caused by an invasive aphid. Plant stress varied among 40 plots through manipulation of aphid densities. Equipped with a consumer-grade near-infrared camera, the UAS was flown on...

  5. National Plant Diagnostic Network, Taxonomic training videos: Aphids under the microscope - Myzus persicae

    Science.gov (United States)

    Training is a critical part of aphid (Hemiptera: Aphididae) identification. This video provides provides training to identify the green peach aphid, Myzus persicae, using a compound microscope and an electronic identification key called “LUCID.” The video demonstrates key morphological structures t...

  6. National Plant Diagnostic Network, Taxonomic training videos: Aphids under the microscope - Cerataphis brasiliensis

    Science.gov (United States)

    Training is a critical part of aphid (Hemiptera: Aphididae) identification. This video provides provides training to identify the palm aphid, Cerataphis brasiliensis, using a compound microscope and an electronic identification key called “LUCID.” The video demonstrates key morphological structures...

  7. National Plant Diagnostic Network, Taxonomic training videos: Aphids under the microscope - Aphis gossypii

    Science.gov (United States)

    Training is a critical part of aphid (Hemiptera: Aphididae) identification. This video provides provides training to identify the cotton aphid, Aphis gossypii, using a compound microscope and an electronic identification key called “LUCID.” The video demonstrates key morphological structures that ca...

  8. Sugarcane aphid (Homoptera: Aphididae): A new pest on sorghum in North America

    Science.gov (United States)

    In 2013 the sugarcane aphid, Melanaphis sacchari (Zehntner) (Hemiptera: Aphididae), a new invasive pest of sorghum in North America, was confirmed on sorghum in four states and 38 counties in the U.S. In 2015, the aphid was reported on sorghum in 17 states and over 400 counties as well as all sorgh...

  9. Screening of sorghum lines for resistance against sugarcane aphid, Melanaphis sacchari (Zehnter)

    Science.gov (United States)

    The sugarcane aphid Melanaphis sacchari (Zehnter) has emerged as the most significant threat to sorghum (Sorghum bicolor (L.) Moench) production in the United States. Since 2013, discovery of aphid resistant germplasm has been a priority all stakeholders involved. We screened twenty three differen...

  10. First report on the entomopathogenic genus Neozygites (Entomophthoromycota) and Neozygites osornensis on aphids in Brazil

    Science.gov (United States)

    The genus Neozygites has been known in Brazil until now only on mites, and this is its first report on aphids in Brazil. Tree-dwelling aphids (Cinara sp.) on a cypress tree were regularly monitored for entomopathogenic fungi in the city of Terezópolis de Goiás in Central Brazil between July 2014 and...

  11. The molecular basis of the interactions between luteoviruses and their aphid vectors

    NARCIS (Netherlands)

    Hogenhout, S.A.

    1999-01-01

    Luteoviruses essentially replicate in the phloem tissue and are transmitted from plant to plant by aphids in a circulative, persistent manner. Virus particles are acquired when aphids feed on phloem sap. Particles are then transported from the midgut or hindgut into the haemolymph and from the haemo

  12. Selection by phage display of a mustard chymotrypsin inhibitor toxic to pea aphid.

    NARCIS (Netherlands)

    Ceci, L.R.; Volpicella, M.; Conti, S.; Gallerani, R.; Beekwilder, M.J.; Jongsma, M.A.

    2003-01-01

    The mustard trypsin inhibitor, MTI-2, is a potent inhibitor of trypsin with no activity towards chymotrypsin. MTI-2 is toxic for lepidopteran insects, but has low activity against aphids. In an attempt to improve the activity of the inhibitor towards aphids, a library of inhibitor variants was const

  13. Soybean Aphid Infestation Induces Changes in Fatty Acid Metabolism in Soybean.

    Directory of Open Access Journals (Sweden)

    Charles Kanobe

    Full Text Available The soybean aphid (Aphis glycines Matsumura is one of the most important insect pests of soybeans in the North-central region of the US. It has been hypothesized that aphids avoid effective defenses by inhibition of jasmonate-regulated plant responses. Given the role fatty acids play in jasmonate-induced plant defenses, we analyzed the fatty acid profile of soybean leaves and seeds from aphid-infested plants. Aphid infestation reduced levels of polyunsaturated fatty acids in leaves with a concomitant increase in palmitic acid. In seeds, a reduction in polyunsaturated fatty acids was associated with an increase in stearic acid and oleic acid. Soybean plants challenged with the brown stem rot fungus or with soybean cyst nematodes did not present changes in fatty acid levels in leaves or seeds, indicating that the changes induced by aphids are not a general response to pests. One of the polyunsaturated fatty acids, linolenic acid, is the precursor of jasmonate; thus, these changes in fatty acid metabolism may be examples of "metabolic hijacking" by the aphid to avoid the induction of effective defenses. Based on the changes in fatty acid levels observed in seeds and leaves, we hypothesize that aphids potentially induce interference in the fatty acid desaturation pathway, likely reducing FAD2 and FAD6 activity that leads to a reduction in polyunsaturated fatty acids. Our data support the idea that aphids block jasmonate-dependent defenses by reduction of the hormone precursor.

  14. Relationships Between Aphids (Insecta: Homoptera: Aphididae) and Slugs (Gastropoda: Stylommatophora: Agriolimacidae) Pests of Legumes (Fabaceae: Lupinus).

    Science.gov (United States)

    Kozłowski, Jan; Strażyński, Przemysław; Jaskulska, Monika; Kozłowska, Maria

    2016-01-01

    Lupin plants are frequently damaged by various herbivorous invertebrates. Significant among these are slugs and aphids, which sometimes attack the same plants. Relationships between aphids, slugs and food plant are very interesting. Grazing by these pests on young plants can lead to significant yield losses. There is evidence that the alkaloids present in some lupin plants may reduce grazing by slugs, aphids and other invertebrates. In laboratory study was analyzed the relationships between aphid Aphis craccivora and slug Deroceras reticulatum pests of legumes Lupinus angustifolius. It was found that the presence of aphids significantly reduced slug grazing on the plants. The lupin cultivars with high alkaloid content were found to be less heavily damaged by D. reticulatum, and the development of A. craccivora was found to be inhibited on such plants.

  15. Reliable screening technique for evaluation of wild crucifers against mustard aphid Lipaphis erysimi (Kalt.).

    Science.gov (United States)

    Singh, S P; Kumar, Sandeep; Singh, Y P; Singh, Ram

    2014-12-01

    Wild crucifers namely Arabidopsis thaliana, Brassica fruticulosa, B. rugosa, B. spinescens, B. tournefortii, Camelina sativa, Capsella bursa-pastoris, Crambe abysinnica, Cronopus didymus, Diplotaxis assurgens, D. gomez-campoi, D. muralis, D. siettiana, D. tenuisiliqua, Enatharocarpus lyratus, Lepidium sativum and Sinapis alba along with five cultivated Brassica species including B. rapa (BSH-1), B. juncea (Rohini), B. napus (GSC-6), B. carinata (DLSC-2) and Eruca sativa (T-27) were screened against mustard aphid Lipaphis erysimi (Kalt.) with a standardized technique under definite level of aphid pressure developed using specially designed cages. Observations have revealed that B. fruticulosa, B. spinescens, Camelina sativa, Crambe abysinnica and Lepidium sativum were resistant to mustard aphid L. erysimi with aphid infestation index (AII) ≤ 1. Capsella bursa-pastoris was highly susceptible to bean aphid, Aphis fabae during its vegetative stage (with 100% mortality). Other genotypes were found in the range of 'susceptible' to 'highly susceptible' with AII ranging 3-5.

  16. What is the economic threshold of soybean aphids (Hemiptera: Aphididae) in enemy-free space?

    Science.gov (United States)

    McCarville, M T; Kanobe, C; MacIntosh, G C; O'Neal, M

    2011-06-01

    Soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is a serious pest of soybean, Glycine max (L.) Merr., in the North Central United States. Current management recommendations rely on the application of insecticides based on an economic threshold (ET) of 250 aphids per plant. Natural enemies are important in slowing the increase of aphid populations and can prevent them from reaching levels that can cause economic losses. However, biological control of A. glycines is inconsistent and can be affected negatively by the intensity of agricultural activity. We measured the impact of a natural-enemy-free environment on the capacity of the current ET to limit yield loss. In 2008 and 2009, caged microplots were assigned to one of three treatments: plants kept aphid-free (referred to as the control), plants that experienced a population of 250 aphids per plant (integrated pest management [IPM]), and plants that experienced unlimited aphid population growth (unlimited). The population growth rate of aphids in the unlimited treatment for the 10 d after the application of insecticides to the IPM treatment was calculated using linear regression. The linear equation was solved to determine the mean number of days between the ET and the EIL for an aphid population in absence of predators. The number of days was determined to be 6.97 +/- 1.11 d. The 2-yr average yield for the IPM treatment was 99.93% of the control treatment. Our study suggests the current soybean aphid ET of 250 aphids per plant can effectively protect yield even if the impact of natural enemies is reduced.

  17. Methyl salicylate attracts natural enemies and reduces populations of soybean aphids (Hemiptera: Aphididae) in soybean agroecosystems.

    Science.gov (United States)

    Mallinger, Rachel E; Hogg, David B; Gratton, Claudio

    2011-02-01

    Methyl salicylate, an herbivore-induced plant volatile, has been shown to attract natural enemies and affect herbivore behavior. In this study, methyl salicylate was examined for its attractiveness to natural enemies of the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), and for its direct effects on soybean aphid population growth rates. Methyl salicylate lures were deployed in plots within organic soybean [Glycine max (L.) Merr.] fields. Sticky card traps adjacent to and 1.5 m from the lure measured the relative abundance of natural enemies, and soybean aphid populations were monitored within treated and untreated plots. In addition, exclusion cage studies were conducted to determine methyl salicylate's effect on soybean aphid population growth rates in the absence of natural enemies. Significantly greater numbers of syrphid flies (Diptera: Syrphidae) and green lacewings (Neuroptera: Chrysopidae) were caught on traps adjacent to the methyl salicylate lure, but no differences in abundance were found at traps 1.5 m from the lure. Furthermore, abundance of soybean aphids was significantly lower in methyl salicylate-treated plots. In exclusion cage studies, soybean aphid numbers were significantly reduced on treated soybean plants when all plants were open to natural enemies. When plants were caged, however, soybean aphid numbers and population growth rates did not differ between treated and untreated plants suggesting no effect of methyl salicylate on soybean aphid reproduction and implicating the role of natural enemies in depressing aphid populations. Although aphid populations were reduced locally around methyl salicylate lures, larger scale studies are needed to assess the technology at the whole-field scale.

  18. Early-season predation on aphids by winter-active spiders in apple orchards revealed by diagnostic PCR.

    Science.gov (United States)

    Boreau de Roincé, C; Lavigne, C; Mandrin, J-F; Rollard, C; Symondson, W O C

    2013-04-01

    Aphids are major pests in apple orchards, debilitating the crop and spreading disease. We investigated whether early-season predation by canopy spiders may be effectively controlling aphid numbers in three organic orchards. For this purpose, we monitored the aphid population dynamics from the winter eggs to colony stages and compared this to spider abundances and rates of predation on aphids detected by diagnostic polymerase chain reaction. For the latter, we applied existing general aphid primers. We found that spiders ate colony fundatrices and that aphid numbers were negatively related to spider abundance. Spiders were the main active predators within the orchards when the first colony fundatrices were present, indicating their importance in the early control of aphid populations.

  19. Analysis of nucleolar pre-rRNA processing sites in pea(Pisum sativum)

    Institute of Scientific and Technical Information of China (English)

    LONG; Hong; (龙; 鸿); ZENG; Xianlu; (曾宪录); JIAO; Mingda; (焦明大); HU; Bo; (胡; 波); SUN; Haijing; (孙海晶); LIU; Zhenlan; (刘振兰); ZHANG; Liyong; (张立勇); HAO; Shui; (郝; 水)

    2003-01-01

    The location of rRNA processing was analyzed by using in situ hybridization with ITS1 probe and immunolabeling of anti-fibrillarin mAb in pea (Pisum sativum) root pole cells. The results showed that rRNA processing sites were in dense fibrillar components (DFCs) and granular components (GCs), but not in fibrillar centers (FCs). Low doses of actinomycin D (AMD) treatment can selectively suppress pre-rRNA synthesis but cannot disturb the processing of preformed pre-rRNAs. With AMD treatment prolonged, the density of labeled signals gradually decreased, indicating the preformed pre-rRNAs were gradually processed.

  20. Effect of sodium fluoride on phytase activity during germination of Pisum sativum L. seeds

    Energy Technology Data Exchange (ETDEWEB)

    Hauskrecht, I.

    1972-01-01

    The effects of fluoride ion, in concentrations varying from 0 to 4 mM F/sup -/, on phytase activity in the course of germination of Pisum sativum L. seeds and in the course of incubation in vitro are reported. The fluoride ion in 1 mM concentration cause a significant 80% decrease of the phytase activity in the incubation medium and a 24% decrease in the course of germination. The inhibition of phytase, as well as its synthesis, by fluoride ion during germination may influence the metabolism of phosphorus at the initial stage of ontogenesis.

  1. Nitrogen and phosphorus compounds in the aleurone grains of Iris pseudoacorus endosperm and Pisum sativum cotyledons

    Directory of Open Access Journals (Sweden)

    Ligia Konopska

    2015-05-01

    Full Text Available Aleurone grains from Iris pseudoacorus endosperm and Pisum sativum cotyledons were isolated partly according to Tombs's method (1967. Nitrogen compounds content was determined in them by Kjeldahl's micromethod, and in the particular fractions after Thiman and Laloraya (1960. Mainly protein N was detected in the aleurone grains, constituting 14.8 and 15.2 per cent of the dry mass of pea and Iris seeds, respectively. Moreover, phosphorus compounds were fractionated according to Holden and Pirie (1955. Analyses demonstrated the presence in aleurone grains of inorganic P, acid-soluble organophosphorus compounds, phospholipids and RNA.

  2. A trio of viral proteins tunes aphid-plant interactions in Arabidopsis thaliana.

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    Jack H Westwood

    Full Text Available BACKGROUND: Virus-induced deterrence to aphid feeding is believed to promote plant virus transmission by encouraging migration of virus-bearing insects away from infected plants. We investigated the effects of infection by an aphid-transmitted virus, cucumber mosaic virus (CMV, on the interaction of Arabidopsis thaliana, one of the natural hosts for CMV, with Myzus persicae (common names: 'peach-potato aphid', 'green peach aphid'. METHODOLOGY/PRINCIPAL FINDINGS: Infection of Arabidopsis (ecotype Col-0 with CMV strain Fny (Fny-CMV induced biosynthesis of the aphid feeding-deterrent 4-methoxy-indol-3-yl-methylglucosinolate (4MI3M. 4MI3M inhibited phloem ingestion by aphids and consequently discouraged aphid settling. The CMV 2b protein is a suppressor of antiviral RNA silencing, which has previously been implicated in altering plant-aphid interactions. Its presence in infected hosts enhances the accumulation of CMV and the other four viral proteins. Another viral gene product, the 2a protein (an RNA-dependent RNA polymerase, triggers defensive signaling, leading to increased 4MI3M accumulation. The 2b protein can inhibit ARGONAUTE1 (AGO1, a host factor that both positively-regulates 4MI3M biosynthesis and negatively-regulates accumulation of substance(s toxic to aphids. However, the 1a replicase protein moderated 2b-mediated inhibition of AGO1, ensuring that aphids were deterred from feeding but not poisoned. The LS strain of CMV did not induce feeding deterrence in Arabidopsis ecotype Col-0. CONCLUSIONS/SIGNIFICANCE: Inhibition of AGO1 by the 2b protein could act as a booby trap since this will trigger antibiosis against aphids. However, for Fny-CMV the interplay of three viral proteins (1a, 2a and 2b appears to balance the need of the virus to inhibit antiviral silencing, while inducing a mild resistance (antixenosis that is thought to promote transmission. The strain-specific effects of CMV on Arabidopsis-aphid interactions, and differences

  3. Estimating ancestral geographical distributions: a Gondwanan origin for aphid parasitoids?

    Science.gov (United States)

    Belshaw, R; Dowton, M; Quicke, D L; Austin, A D

    2000-01-01

    We tested the published hypothesis of a Gondwanan origin for the overwhelmingly northern hemisphere aphid parasitoids (Aphidiinae) as follows: (i) finding their sister group by a phylogenetic analysis of the entire Braconidae (Insecta: Hymenopterai using sequence data from approximately 500 bp fragments of both the nuclear 28S (D2 region) and mitochondrial 16S rDNA genes, (ii) using this sister-group relationship and the more informative 28S D2 gene to estimate the phylogeny of the Aphidiinae and (iii) estimating the ancestral distribution for the Aphidiinae using maximum-likelihood and maximum-parsimony methods. Both methods indicated a Gondwanan origin. PMID:10737407

  4. Cucumis melo microRNA expression profile during aphid herbivory in a resistant and susceptible interaction.

    Science.gov (United States)

    Sattar, Sampurna; Song, Yan; Anstead, James A; Sunkar, Ramanjulu; Thompson, Gary A

    2012-06-01

    Aphis gossypii resistance in melon (Cucumis melo) is due to the presence of a single dominant virus aphid transmission (Vat) gene belonging to the nucleotide-binding site leucine-rich repeat family of resistance genes. Significant transcriptional reprogramming occurs in Vat(+) plants during aphid infestation as metabolism shifts to respond to this biotic stress. MicroRNAs (miRNAs) are involved in the regulation of many biotic stress responses. The role of miRNAs was investigated in response to aphid herbivory during both resistant and susceptible interactions. Small RNA (smRNA) libraries were constructed from bulked leaf tissues of a Vat(+) melon line following early and late aphid infestations. Sequence analysis indicated that the expression profiles of conserved and newly identified miRNAs were altered during different stages of aphid herbivory. These results were verified by quantitative polymerase chain reaction experiments in both resistant Vat(+) and susceptible Vat(-) interactions. The comparative analyses revealed that most of the conserved miRNA families were differentially regulated during the early stages of aphid infestation in the resistant and susceptible interactions. Along with the conserved miRNA families, 18 cucurbit-specific miRNAs were expressed during the different stages of aphid herbivory. The comparison of the miRNA profiles in the resistant and susceptible interactions provides insight into the miRNA-dependent post-transcriptional gene regulation in Vat-mediated resistance.

  5. Differential expression of superoxide dismutase genes in aphid-stressed maize (Zea mays L. seedlings.

    Directory of Open Access Journals (Sweden)

    Hubert Sytykiewicz

    Full Text Available The aim of this study was to compare the expression patterns of superoxide dismutase genes (sod2, sod3.4, sod9 and sodB in seedling leaves of the Zea mays L. Tasty Sweet (susceptible and Ambrozja (relatively resistant cultivars infested with one of two hemipteran species, namely monophagous Sitobion avenae F. (grain aphid or oligophagous Rhopalosiphum padi L. (bird cherry-oat aphid. Secondarily, aphid-elicited alternations in the antioxidative capacity towards DPPH (1,1-diphenyl-2-picrylhydrazyl radical in insect-stressed plants were evaluated. Comprehensive comparison of expression profiles of the four sod genes showed that both insect species evoked significant upregulation of three genes sod2, sod3.4 and sod9. However, aphid infestation affected non-significant fluctuations in expression of sodB gene in seedlings of both maize genotypes. The highest levels of transcript accumulation occurred at 8 h (sod2 and sod3.4 or 24 h (sod9 post-infestation, and aphid-induced changes in the expression of sod genes were more dramatic in the Ambrozja cultivar than in the Tasty Sweet variety. Furthermore, bird cherry-oat aphid colonization had a more substantial impact on levels of DPPH radical scavenging activity in infested host seedlings than grain aphid colonization. Additionally, Ambrozja plants infested by either hemipteran species showed markedly lower antioxidative capacity compared with attacked Tasty Sweet plants.

  6. Differential expression of superoxide dismutase genes in aphid-stressed maize (Zea mays L.) seedlings.

    Science.gov (United States)

    Sytykiewicz, Hubert

    2014-01-01

    The aim of this study was to compare the expression patterns of superoxide dismutase genes (sod2, sod3.4, sod9 and sodB) in seedling leaves of the Zea mays L. Tasty Sweet (susceptible) and Ambrozja (relatively resistant) cultivars infested with one of two hemipteran species, namely monophagous Sitobion avenae F. (grain aphid) or oligophagous Rhopalosiphum padi L. (bird cherry-oat aphid). Secondarily, aphid-elicited alternations in the antioxidative capacity towards DPPH (1,1-diphenyl-2-picrylhydrazyl) radical in insect-stressed plants were evaluated. Comprehensive comparison of expression profiles of the four sod genes showed that both insect species evoked significant upregulation of three genes sod2, sod3.4 and sod9). However, aphid infestation affected non-significant fluctuations in expression of sodB gene in seedlings of both maize genotypes. The highest levels of transcript accumulation occurred at 8 h (sod2 and sod3.4) or 24 h (sod9) post-infestation, and aphid-induced changes in the expression of sod genes were more dramatic in the Ambrozja cultivar than in the Tasty Sweet variety. Furthermore, bird cherry-oat aphid colonization had a more substantial impact on levels of DPPH radical scavenging activity in infested host seedlings than grain aphid colonization. Additionally, Ambrozja plants infested by either hemipteran species showed markedly lower antioxidative capacity compared with attacked Tasty Sweet plants.

  7. A cost of alarm pheromone production in cotton aphids, Aphis gossypii

    Science.gov (United States)

    Byers, John A.

    2005-02-01

    The sesquiterpene, (E)-β-farnesene, is used by many aphid species as an alarm pheromone to warn related individuals of predation. Disturbed cotton aphids, Aphis gossypii Glover, released (E)-β-farnesene into the air as detected by solid phase microextraction and gas chromatography mass spectrometry (GC MS). Solvent extracts of cotton aphids of various life stages and weights also were analyzed by GC MS for sums of ions 69 and 93, which discriminated (E)-β-farnesene from coeluting compounds. Aphids of all life stages and sizes reared on cotton plants in both an environmental chamber and glasshouse contained (E)-β-farnesene in amounts ranging from 0.1 to 1.5 ng per individual. The quantities of (E)-β-farnesene in aphids increased in relation to increasing body weight, and variation in individual weights explained about 82% of the variation in alarm pheromone. However, the concentrations (ng/mg fresh weight) declined exponentially with increasing body weight. These findings indicate that aphid nymphs try to compensate for their smaller size by producing relatively more pheromone per weight than adults but still cannot approach an evolutionary optimal load, as assumed in adults with the greatest total amounts. This suggests that young aphids need to balance costs of growth and maturation with costs of producing the alarm pheromone.

  8. Plant genotype shapes ant-aphid interactions: implications for community structure and indirect plant defense.

    Science.gov (United States)

    Mooney, Kailen A; Agrawal, Anurag A

    2008-06-01

    Little is known about the mechanisms by which plant genotype shapes arthropod community structure. In a field experiment, we measured the effects of milkweed (Asclepias syriaca) genotype and ants on milkweed arthropods. Populations of the ant-tended aphid Aphis asclepiadis and the untended aphid Myzocallis asclepiadis varied eight- to 18-fold among milkweed genotypes, depending on aphid species and whether ants were present. There was no milkweed effect on predatory arthropods. Ants increased Aphis abundance 59%, decreased Myzocallis abundance 52%, and decreased predator abundance 56%. Milkweed genotype indirectly influenced ants via direct effects on Aphis and Myzocallis abundance. Milkweed genotype also modified ant-aphid interactions, influencing the number of ants attracted per Aphis and Myzocallis. While ant effects on Myzocallis were consistently negative, effects on Aphis ranged from antagonistic to mutualistic among milkweed genotypes. As a consequence of milkweed effects on ant-aphid interactions, ant abundance varied 13-fold among milkweed genotypes, and monarch caterpillar survival was negatively correlated with genetic variation in ant abundance. We speculate that heritable variation in milkweed phloem sap drives these effects on aphids, ants, and caterpillars. In summary, milkweed exerts genetic control over the interactions between aphids and an ant that provides defense against foliage-feeding caterpillars.

  9. Studies on the Host Biotypes and Its Cause of Cotton Aphid in Nanjing, China

    Institute of Scientific and Technical Information of China (English)

    LIU Xiang-dong; ZHAI Bao-ping; ZHANG Xiao-xi

    2002-01-01

    The fitness of cotton aphid, Aphis gossypii Glover, on different host plants was studied. The results showed that the cotton aphid population in Nanjing formed host preference bio-types on cucumber and cotton. The aphids from cotton and cucumber could not inter-transplant successfully between the two host plants. The apterous and alate offspring of stem mother from hibiscus could not survive, reproduce and form population normally when they were transplanted to cucumber and water melon, but they could form normally when transplanted to cotton and muskmelon. There was no significant difference between the stylet length of cotton aphids from cucumber and cotton, so the stylet length was not the cause of the host preference. When the aphids originated on hibiscus were transplanted to cotton, water melon and muskmelon, the stylet could reach host phloem to absorb host plant's nutrients, but it couldn't when transplanted to cucumber. Cotton aphid can feed on muskmelon without secretion of water-soluble saliva. It could be concluded that the two host biotypes of cotton aphid came from different winter host plants.

  10. Indirect effect of a transgenic wheat on aphids through enhanced powdery mildew resistance.

    Directory of Open Access Journals (Sweden)

    Simone von Burg

    Full Text Available In agricultural ecosystems, arthropod herbivores and fungal pathogens are likely to colonise the same plant and may therefore affect each other directly or indirectly. The fungus that causes powdery mildew (Blumeria graminis tritici and cereal aphids are important pests of wheat but interactions between them have seldom been investigated. We studied the effects of powdery mildew of wheat on two cereal aphid species, Metopolophium dirhodum and Rhopalosiphum padi. We hypothesized that aphid number and size will be smaller on powdery mildew-infected plants than on non-infected plants. In a first experiment we used six commercially available wheat varieties whereas in the second experiment we used a genetically modified (GM mildew-resistant wheat line and its non-transgenic sister line. Because the two lines differed only in the presence of the transgene and in powdery mildew resistance, experiment 2 avoided the confounding effect of variety. In both experiments, the number of M. dirhodum but not of R. padi was reduced by powdery mildew infection. Transgenic mildew-resistant lines therefore harboured bigger aphid populations than the non-transgenic lines. For both aphid species individual size was mostly influenced by aphid number. Our results indicate that plants that are protected from a particular pest (powdery mildew became more favourable for another pest (aphids.

  11. Indirect effect of a transgenic wheat on aphids through enhanced powdery mildew resistance.

    Science.gov (United States)

    von Burg, Simone; Álvarez-Alfageme, Fernando; Romeis, Jörg

    2012-01-01

    In agricultural ecosystems, arthropod herbivores and fungal pathogens are likely to colonise the same plant and may therefore affect each other directly or indirectly. The fungus that causes powdery mildew (Blumeria graminis tritici) and cereal aphids are important pests of wheat but interactions between them have seldom been investigated. We studied the effects of powdery mildew of wheat on two cereal aphid species, Metopolophium dirhodum and Rhopalosiphum padi. We hypothesized that aphid number and size will be smaller on powdery mildew-infected plants than on non-infected plants. In a first experiment we used six commercially available wheat varieties whereas in the second experiment we used a genetically modified (GM) mildew-resistant wheat line and its non-transgenic sister line. Because the two lines differed only in the presence of the transgene and in powdery mildew resistance, experiment 2 avoided the confounding effect of variety. In both experiments, the number of M. dirhodum but not of R. padi was reduced by powdery mildew infection. Transgenic mildew-resistant lines therefore harboured bigger aphid populations than the non-transgenic lines. For both aphid species individual size was mostly influenced by aphid number. Our results indicate that plants that are protected from a particular pest (powdery mildew) became more favourable for another pest (aphids).

  12. Differential Life History Trait Associations of Aphids with Nonpersistent Viruses in Cucurbits.

    Science.gov (United States)

    Angelella, G M; Egel, D S; Holland, J D; Nemacheck, J A; Williams, C E; Kaplan, I

    2015-06-01

    The diversity of vectors and fleeting nature of virus acquisition and transmission renders nonpersistent viruses a challenge to manage. We assessed the importance of noncolonizing versus colonizing vectors with a 2-yr survey of aphids and nonpersistent viruses on commercial pumpkin farms. We quantified aphid alightment using pan traps, while testing leaf samples with multiplex RT-PCR targeting cucumber mosaic virus (CMV), zucchini yellow mosaic virus (ZYMV), watermelon mosaic virus (WMV), and papaya ringspot virus (PRSV). Overall, we identified 53 aphid species (3,899 individuals), from which the melon aphid, Aphis gossypii Glover, a pumpkin-colonizing species, predominated (76 and 37% of samples in 2010 and 2011, respectively). CMV and ZYMV were not detected, but WMV and PRSV were prevalent, both regionally (WMV: 28/29 fields, PRSV: 21/29 fields) and within fields (infection rates = 69 and 55% for WMV in 2010 and 2011; 28 and 25% for PRSV in 2010 and 2011). However, early-season samples showed extremely low infection levels, suggesting cucurbit viruses are not seed-transmitted and implicating aphid activity as a causal factor driving virus spread. Interestingly, neither noncolonizer and colonizer alightment nor total aphid alightment were good predictors of virus presence, but community analyses revealed species-specific relationships. For example, cowpea aphid (Aphis craccivora Koch) and spotted alfalfa aphid (Therioaphis trifolii Monell f. maculata) were associated with PRSV infection, whereas the oleander aphid (Aphis nerii Bover de Fonscolombe) was associated with WMV spread within fields. These outcomes highlight the need for tailored management plans targeting key vectors of nonpersistent viruses in agricultural systems.

  13. Widespread infection and diverse infection patterns of Wolbachia in Chinese aphids.

    Science.gov (United States)

    Wang, Zhe; Su, Xiao-Min; Wen, Juan; Jiang, Li-Yun; Qiao, Ge-Xia

    2014-06-01

    Wolbachia are intracellular symbionts that infect a wide range of arthropods and filarial nematodes. Aphids are engaged in diverse and complex relationships with their endosymbionts. Four supergroups (A, B, M and N) of Wolbachia were previously detected in aphids and supergroups M and N were only found in aphids. In this study, we detected and described Wolbachia infections in natural populations of aphids in China. Three supergroups (A, B and M) were found in the examined aphid species. Supergroup M was preponderant, whereas supergroups A and B were only detected in certain species. Supergroup N was not found in this study. There were four infection patterns of Wolbachia in aphids, namely, infection with supergroup M alone, co-infection with supergroups A and M, co-infection with supergroups B and M, and co-infection with supergroups A, B and M. The pattern of infection only with supergroup M was universal and was found in all evaluated subfamilies. Only two subfamilies, Aphidinae and Lachninae, manifested to present all four infection patterns. Three patterns were observed in Calaphidinae (M, A&M, B&M) and Eriosomatinae (M, B&M, A&B&M). Two patterns were observed in the Anoeciinae (M, A&M) and Greenideinae (M, B&M), and only one pattern (M) was observed in the remaining families and/or subfamilies of Aphidoidea. These results indicated that Wolbachia infections in Chinese aphids are widespread. Phylogenetic analyses suggest that Wolbachia supergroup M spread rapidly and recently among all host species of aphids in China. Reasons for this spread and its mechanisms are discussed along with the possible effects of Wolbachia on their aphid hosts.

  14. Effect of sodium fluoride and sodium nitroprouside on Cicer arietinum and Pisum sativum

    Directory of Open Access Journals (Sweden)

    Naba Kumar Mondal

    2016-07-01

    Full Text Available In present study, the individual and combine effect of sodium fluoride (NaF and sodium nitroprouside (SNP on germination and biochemical parameters (pigments, sugar, protein, amino acid, and phenol of Bengal gram (Cicer arietinum and peas (Pisum sativum has been studied. After three days of NaF treatment, reductions were observed in percentage of seed germination, root and shoot length, and pigment content with increasing concentration of NaF (1 to 4 mg L-1. Seedlings treated with SNP, both alone and in combination of NaF, showed enhancement in seed germination as well as other growth parameters. NaF-treated seedlings were found to accumulate more soluble sugars and phenols, which were further increased by SNP treatment thereby indicating a synergistic effect of the possible reasons for the ameliorative effects of SNP in seedlings of Pisum sativum growing under NaF stress. Results also demonstrated that SNP application did not show any improvement in both morpho-physiologically and biochemically under sodium fluoride stress condition.

  15. Growth and some physiological attributes of pea (Pisum sativum L.) as affected by salinity.

    Science.gov (United States)

    Najafi, F; Khavari-Nejad, R A; Rastgar-Jazii, F; Sticklen, M

    2007-08-15

    The effects of salt stress were studied on growth and physiology of pea (Pisum sativum L. cv. Green Arrow) in a pot study. Pea plants were treated with NaCl at 0, 10, 30, 50 and 70 mM in Hoagland solution. Plants were harvested after 21 days for measurements of physiological parameters. The highest NAR and RGR were found in 10 mM NaCl. However, in 70 mM NaCl, RGR and RLGR were significantly decreased in respect of other concentrations of NaCl. In 50 and 70 mM NaCl, chlorophylls contents and photosynthetic rate, were significantly decreased and CO2 compensation concentration and respiration rate increased in comparison with control. In 10 and 30 mM NaCl gas exchanges and chlorophyll contents were not significantly decrease in respect of control. Results indicated that Pisum sativum L. cv. Green Arrow can tolerate to 70 mM NaCl, also growth of plants in 10 and 30 mM NaCl was better than that of those in 0 mM NaCl.

  16. Rhizobium anhuiense sp. nov., isolated from effective nodules of Vicia faba and Pisum sativum.

    Science.gov (United States)

    Zhang, Yu Jing; Zheng, Wen Tao; Everall, Isobel; Young, J Peter W; Zhang, Xiao Xia; Tian, Chang Fu; Sui, Xin Hua; Wang, En Tao; Chen, Wen Xin

    2015-09-01

    Four rhizobia-like strains, isolated from root nodules of Pisum sativum and Vicia faba grown in Anhui and Jiangxi Provinces of China, were grouped into the genus Rhizobium but were distinct from all recognized species of the genus Rhizobium by phylogenetic analysis of 16S rRNA and housekeeping genes. The combined sequences of the housekeeping genes atpD, recA and glnII for strain CCBAU 23252(T) showed 86.9 to 95% similarity to those of known species of the genus Rhizobium. All four strains had nodC and nifH genes and could form effective nodules with Pisum sativum and Vicia faba, and ineffective nodules with Phaseolus vulgaris, but did not nodulate Glycine max, Arachis hypogaea, Medicago sativa, Trifolium repens or Lablab purpureus in cross-nodulation tests. Fatty acid composition, DNA-DNA relatedness and a series of phenotypic tests also separated these strains from members of closely related species. Based on all the evidence, we propose a novel species, Rhizobium anhuiense sp. nov., and designate CCBAU 23252(T) ( = CGMCC 1.12621(T) = LMG 27729(T)) as the type strain. This strain was isolated from a root nodule of Vicia faba and has a DNA G+C content of 61.1 mol% (Tm).

  17. Characterisation and cross-amplification of polymorphic microsatellite loci in ant-associated root-aphids

    DEFF Research Database (Denmark)

    Ivens, A.B.F.; Kronauer, Daniel Jan Christoph; Boomsma, J.J.

    2011-01-01

    Twenty-six polymorphic microsatellite loci were developed for four species of ant-associated root-aphids: Geoica utricularia, Forda marginata, Tetraneura ulmi and Anoecia corni. We found up to 9 alleles per locus, with an average of 4.8. We also report polymorphic cross-amplification of eleven...... of these markers between different pairs of study species. Furthermore, we tested previously published aphid microsatellites and found one locus developed for Pemphigus bursarius to be polymorphic in G. utricularia. These microsatellite markers will be useful to study the population structure of aphids associated...

  18. Characterization of low-strigolactone germplasm in pea (Pisum sativum L.) resistant to crenate broomrape (Orobanche crenata Forsk.)

    NARCIS (Netherlands)

    Pavan, Stefano; Schiavulli, Adalgisa; Marcotrigiano, Angelo Raffaele; Bardaro, Nicoletta; Bracuto, Valentina; Ricciardi, Francesca; Charnikhova, Tatsiana; Lotti, Concetta; Bouwmeester, Harro; Ricciardi, Luigi

    2016-01-01

    Crenate broomrape (Orobanche crenata Forsk.) is a devastating parasitic weed threatening the cultivation of legumes around the Mediterranean and in theMiddle East. So far, only moderate levels of resistance were reported to occur in pea (Pisum sativum L.) natural germplasm, and most commercial cu

  19. Effect of clinorotation on the leaf mesophyll structure and pigment content in Arabidopsis thaliana L. and Pisum sativum L.

    Science.gov (United States)

    Adamchuk, N I

    2004-07-01

    Properties of mesophyll cells and photosynthetic membranes of Arabidopsis thaliana (L.) Heynh. and Pisum sativum (L.) plants grown in a horizontal clinostat and in control conditions were compared. Obtained data have show that under clinorotation conditions seedlings have experienced the following cell morphology changes structural chloroplast rearrangement in palisade cells, pigment content alteration, and cell aging acceleration.

  20. Calcium-calmodulin signalling is involved in light-induced acidification by epidermal leaf cells of pea, Pisum sativum L.

    NARCIS (Netherlands)

    Elzenga, JTM; Staal, M; Prins, HBA

    1997-01-01

    Pathways of signal transduction of red and blue light-dependent acidification by leaf epidermal cells were studied using epidermal strips of the Argenteum mutant of Pisum sativum. In these preparations the contribution of guard cells to the acidification is minimal. The hydroxypyridine nifedipine, a

  1. [UV-induced DNA mutation of peach aphid].

    Science.gov (United States)

    Du, Erxia; Guo, Jianwen; Zhao, Huiyan

    2006-07-01

    By using PCR technique and microsatellite marks, this paper studied the DNA polymorphism of peach aphid (Myzus persicae) under UV-radiation. The fragments of three primers were amplified, and the gene diversity and the rate of loci polymorphisms of their genomic DNA, which could reflect the damage degree of DNA after UV-radiation, were measured. The results revealed that after treated with different radiation intensity (15, 30, 45 W) and duration (2, 4, 6 h) , the UV-induced DNA mutations were genetic and could be delivered to F2 generation. The mutations depended on the interaction of radiation intensity and duration. Variance analysis on the gene diversity and the rate of loci polymorphisms showed that there existed a significant difference between UV-treated and control groups, except the rate of loci polymorphisms under 2 h radiation. The average value of the control was higher than that of 2 h radiation treatment. According to the cluster analysis of the genetic distance, the aphids were divided into three groups, i. e., control group, 2 h (15, 30 W) treatment group, and the other, which was consistent with the result of variance analysis.

  2. All 37 Mitochondrial Genes of Aphid Aphis craccivora Obtained from Transcriptome Sequencing: Implications for the Evolution of Aphids.

    Directory of Open Access Journals (Sweden)

    Nan Song

    Full Text Available The availability of mitochondrial genome data for Aphididae, one of the economically important insect pest families, in public databases is limited. The advent of next generation sequencing technology provides the potential to generate mitochondrial genome data for many species timely and cost-effectively. In this report, we used transcriptome sequencing technology to determine all the 37 mitochondrial genes of the cowpea aphid, Aphis craccivora. This method avoids the necessity of finding suitable primers for long PCRs or primer-walking amplicons, and is proved to be effective in obtaining the whole set of mitochondrial gene data for insects with difficulty in sequencing mitochondrial genome by PCR-based strategies. Phylogenetic analyses of aphid mitochondrial genome data show clustering based on tribe level, and strongly support the monophyly of the family Aphididae. Within the monophyletic Aphidini, three samples from Aphis grouped together. In another major clade of Aphididae, Pterocomma pilosum was recovered as a potential sister-group of Cavariella salicicola, as part of Macrosiphini.

  3. Foraging behaviour at the fourth tropic level: a comparative study of host location in aphid hyperparasitoids

    NARCIS (Netherlands)

    Buitenhuis, R.; Vet, L.E.M.; Boivin, G.; Brodeur, J.

    2005-01-01

    In studies of foraging behaviour in a multitrophic context, the fourth trophic level has generally been ignored. We used four aphid hyperparasitoid species: Dendrocerus carpenteri (Curtis) (Hymenoptera: Megaspilidae), Asaphes suspensus Walker (Hymenoptera: Pteromalidae), Alloxysta victrix (Westwood)

  4. Natural enemies of woolly apple aphid (Hemiptera: Aphididae) in Washington State.

    Science.gov (United States)

    Gontijo, Lessando M; Cockfield, Stephen D; Beers, Elizabeth H

    2012-12-01

    Woolly apple aphid, Eriosoma lanigerum (Hausmann), has become a pest of increasing importance in Washington apple orchards in the past decade. The increase in aphid outbreaks appears to be associated with changes in pesticide programs and disruption of biological control. We sampled woolly apple aphid colonies in central Washington apple orchards for natural enemies of this pest from 2006 to 2008. The most common predators encountered were Syrphidae (Syrphus opinator Osten Sacken, Eupeodes fumipennis Thomson, and Eupeodes americanus Wiedemann); Chrysopidae (Chrysopa nigricornis Burmeister); and Coccinellidae (Coccinella transversoguttata Brown and Hippodamia convergens Guérin-Méneville). The specialist syrphid Heringia calcarata Loew was recorded for the first time occurring in Washington apple orchards. The only parasitoid found in aerial colonies of woolly apple aphid was Aphelinus mali Haldeman; root colonies, however, were not parasitized. Identification of important natural enemies provides a better basis for conservation biological control of this pest.

  5. Aphids (Homoptera, Aphidodea inhabiting the trees Crataegus x media Bechst. in the urban green area. Part I. The population dynamics

    Directory of Open Access Journals (Sweden)

    Bożena Jaśkiwicz

    2013-12-01

    Full Text Available The studies were conducted in the years 1999-2001 in the green areas of Lublin, on the trees of Crataegus x media Bechst. The purpose of the studies was to establish the species composition and the population dynamics of aphids inhabiting hawthorn in the street and park sites. The studies found out the presence of four aphid species on the examined trees, namely Aphis pomi De Geer, aphids from the genus Dysaphis Börn., Ovatus crataegarius (Walk. and Rhopalosiphum insertum (Walk.. More aphid species and bigger populations were found in the street site (A as compa red with the park site (B.The weather conditions (air temperatures of over 30°C and stormy rainfalls limited the population of all aphid species. On the other hand, a mild winter and a warm spring with the rainfalls within the norm caused that the number of aphids decreased considerably.

  6. Resistance of Wild Solanum Accessions to Aphids and Other Potato Pests in Quebec Field Conditions

    OpenAIRE

    Fréchette, B.; Bejan, M.; Lucas, É.; Giordanengo, P.; Vincent, C

    2010-01-01

    Two experiments were done to determine the susceptibility of six wild potato accessions to the aphids Macrosiphum euphorbiae (Thomas) (Hemiptera: Aphididae) and Myzus persicae (Sulzer). Densities of aphid colonies were compared between caged Solanum pinnatisectum Dunal (Solanales: Solanaceae), S. polyadenium Greenmam, S. tarijense Hawkes, S. infundibuliforme Philippi, S. oplocense Hawkes, and S. stoloniferum Schlechted and Bouché, and the commercially cultivated potato plant S. tuberosum L. c...

  7. First survey on ecological host range of aphid pathogenic fungi (Phylum Entomophthoromycota) in Tunisia

    DEFF Research Database (Denmark)

    Ben Fekih, Ibtissem; Boukhris-Bouhachem, Sonia; Allagui, Mohamed Bechir;

    2015-01-01

    sites belonging to three different bioclimatic zones. Four pathogens from the phylum Entomophthoromycota were found to occur naturally in Tunisian ecosystems: Pandora neoaphidis (Entomophthorales: Entomophthoraceae), Entomophthora planchoniana (Entomophthorales: Entomophthoraceae), Conidiobolus obscurus...... (Entomophthorales: Ancylistaceae) and Neozygites fresenii (Neozygitales: Neozygitaceae). The occurrence of entomophthoralean fungi depended on the sampling area, the bioclimatic zone, and aphid species. P. neoaphidis and E. planchoniana were the predominant pathogens infecting a wide range of aphid species whereas...

  8. Water stress and aphid feeding differentially influence metabolite composition in Arabidopsis thaliana (L..

    Directory of Open Access Journals (Sweden)

    Inga Mewis

    Full Text Available Little is known about how drought stress influences plant secondary metabolite accumulation and how this affects plant defense against different aphids. We therefore cultivated Arabidopsis thaliana (L. plants under well-watered, drought, and water-logged conditions. Two aphid species were selected for this study: the generalist Myzus persicae (Sulzer and the crucifer specialist Brevicoryne brassicae (L.. Metabolite concentrations in the phloem sap, which influence aphid growth, changed particularly under drought stress. Levels of sucrose and several amino acids, such as glutamic acid, proline, isoleucine, and lysine increased, while concentrations of 4-methoxyindol-3-ylmethyl glucosinolate decreased. M. persicae population growth was highest on plants under drought stress conditions. However, B. brassicae did not profit from improved phloem sap quality under drought stress and performed equally in all water treatments. Water stress and aphids generally had an opposite effect on the accumulation of secondary metabolites in the plant rosettes. Drought stress and water-logging led to increased aliphatic glucosinolate and flavonoid levels. Conversely, aphid feeding, especially of M. persicae, reduced levels of flavonoids and glucosinolates in the plants. Correspondingly, transcript levels of aliphatic biosynthetic genes decreased after feeding of both aphid species. Contrary to M. persicae, drought stress did not promote population growth of B. brassicae on these plants. The specialist aphid induced expression of CYP79B2, CYP79B3, and PAD3 with corresponding accumulation of indolyl glucosinolates and camalexin. This was distinct from M. persicae, which did not elicit similarly strong camalexin accumulation, which led to the hypothesis of a specific defense adaptations against the specialist aphid.

  9. Expression profiling of selected glutathione transferase genes in Zea mays (L.) seedlings infested with cereal aphids.

    Science.gov (United States)

    Sytykiewicz, Hubert; Chrzanowski, Grzegorz; Czerniewicz, Paweł; Sprawka, Iwona; Łukasik, Iwona; Goławska, Sylwia; Sempruch, Cezary

    2014-01-01

    The purpose of this report was to evaluate the expression patterns of selected glutathione transferase genes (gst1, gst18, gst23 and gst24) in the tissues of two maize (Zea mays L.) varieties (relatively resistant Ambrozja and susceptible Tasty Sweet) that were colonized with oligophagous bird cherry-oat aphid (Rhopalosiphum padi L.) or monophagous grain aphid (Sitobion avenae L.). Simultaneously, insect-triggered generation of superoxide anion radicals (O2•-) in infested Z. mays plants was monitored. Quantified parameters were measured at 1, 2, 4, 8, 24, 48 and 72 h post-initial aphid infestation (hpi) in relation to the non-infested control seedlings. Significant increases in gst transcript amounts were recorded in aphid-stressed plants in comparison to the control seedlings. Maximal enhancement in the expression of the gst genes in aphid-attacked maize plants was found at 8 hpi (gst23) or 24 hpi (gst1, gst18 and gst24) compared to the control. Investigated Z. mays cultivars formed excessive superoxide anion radicals in response to insect treatments, and the highest overproduction of O2•- was noted 4 or 8 h after infestation, depending on the aphid treatment and maize genotype. Importantly, the Ambrozja variety could be characterized as having more profound increments in the levels of gst transcript abundance and O2•- generation in comparison with the Tasty Sweet genotype.

  10. Evaluation of late vegetative and reproductive stage soybeans for resistance to soybean aphid (Hemiptera: Aphididae).

    Science.gov (United States)

    Prochaska, T J; Pierson, L M; Baldin, E L L; Hunt, T E; Heng-Moss, T M; Reese, J C

    2013-04-01

    The soybean aphid, Aphis glycines Matsumura, has become the most significant soybean [Glycine max (L.) Merrill] insect pest in the north central soybean production region of North America. The objectives of this research were to measure selected genotypes for resistance to the soybean aphid in the later vegetative and reproductive stages under field conditions, and confirm the presence of tolerance in KS4202. The results from 2007 to 2011 indicate that KS4202 can support aphid populations with minimal yield loss at levels where significant yield loss would be expected in most other genotypes. The common Nebraska cultivar, 'Asgrow 2703', appears to show signs of tolerance as well. None of the yield parameters were significantly different between the aphid infested and noninfested treatments. Based on our results, genotypes may compensate for aphid feeding in different ways. Asgrow 2703 appears to produce a similar number of seeds as its noninfested counterpart, although the seeds produced are slightly smaller. Field evaluation of tolerance in KS4202 indicated a yield loss of only 13% at 34,585-53,508 cumulative aphid-days, when 24-36% yield loss would have been expected.

  11. Identification of differentially expressed genes related to aphid resistance in cucumber (Cucumis sativus L.).

    Science.gov (United States)

    Liang, Danna; Liu, Min; Hu, Qijing; He, Min; Qi, Xiaohua; Xu, Qiang; Zhou, Fucai; Chen, Xuehao

    2015-05-11

    Cucumber, a very important vegetable crop worldwide, is easily damaged by pests. Aphids (Aphis gossypii Glover) are among the most serious pests in cucumber production and often cause severe loss of yield and make fruit quality get worse. Identifying genes that render cucumbers resistant to aphid-induced damage and breeding aphid-resistant cucumber varieties have become the most promising control strategies. In this study, a Illumina Genome Analyzer platform was applied to monitor changes in gene expression in the whole genome of the cucumber cultivar 'EP6392' which is resistant to aphids. Nine DGE libraries were constructed from infected and uninfected leaves. In total, 49 differentially expressed genes related to cucumber aphid resistance were screened during the treatment period. These genes are mainly associated with signal transduction, plant-pathogen interactions, flavonoid biosynthesis, amino acid metabolism and sugar metabolism pathways. Eight of the 49 genes may be associated with aphid resistance. Finally, expression of 9 randomly selected genes was evaluated by qRT-PCR to verify the results for the tag-mapped genes. With the exception of 1-aminocyclopropane-1-carboxylate oxidase homolog 6, the expression of the chosen genes was in agreement with the results of the tag-sequencing analysis patterns.

  12. Response of root fungi in Pisum sativum to plant and soil environmental factors

    DEFF Research Database (Denmark)

    Yu, Lingling

    , Pisum sativum was used as a model crop to study fungal community structure associated with roots under different environmental conditions. Three individual experiments were conducted in order to study root-associated fungal community structure in relation to root-internal factors in terms of plant...... health status and plant growth stage and, to a root-external condition in terms of organic fertilization. For identification and semi-quantification of fungal taxa, pyrosequencing combined with DNA barcode technology was applied in this study. Two primer sets (ITS1F/ITS2 and ITS1F/ITS4) from ITS regions...... analysis, analysis of variance (ANOVA) was used in the measurement of plant growth parameters and relative abundance of root-associated fungi, and principle component analysis (PCA) was used to examine the response of communities of root fungi to the plant and soil environmental factors. vi The three...

  13. On the shock response of Pisum Sativum (a.k.a the Common Pea)

    Science.gov (United States)

    Leighs, James; Hazell, Paul; Appleby-Thomas, Gareth

    2011-06-01

    The high strain-rate response of biological and organic structures is of interest to numerous fields ranging from the food industry (dynamic pasteurisation) to astrobiology (e.g. the theory of panspermia, which suggests that planets could be `seeded' with life `piggy-backing' of interplanetary bodies). Consequently, knowledge of the damage mechanisms and viability of shocked organic material is of paramount importance. In this study a single-stage gas-gun has been employed to subject samples of Pisum Sativum (the Common Pea) to semi-planar shock loading, corresponding to impact pressures of up to c.3 GPa. The experimental approach adopted is discussed along with results from Manganin gauges embedded in the target capsule which show the loading history. Further, the viability of the shock-loaded peas was investigated via attempts at germination. Finally, microscopic examination of the impacted specimens allowed a qualitative assessment of damage mechanisms to be made.

  14. Cultivar and Rhizobium Strain Effects on the Symbiotic Performance of Pea (Pisum sativum)

    DEFF Research Database (Denmark)

    Skøt, Leif

    1983-01-01

    content and dry weight/N ratio. At harvest 63 days after planting, cultivars accounted for 75% of the variation in dry weight, while the Rhizobium strains accounted for 63% of the variation in N-content and 70% of the variation in dry weight/N ratio. Cultivar × strain interactions were statistically......The symbiotic performance of four pea (Pisum sativum L.) cultivars in combination with each of four strains of Rhizobium leguminosarum was studied in growth chamber experiments in order to estimate the effects of cultivars, strains and cultivar × strain interaction on the variation in dry weight, N...... significant, but of minor quantitative importance, accounting for 5–15% of the total variation. Rhizobium strains also influenced the partitioning of N between reproductive and vegetative plant parts and between root and shoot biomass....

  15. Identification of the 64 kilodalton chloroplast stromal phosphoprotein as phosphoglucomutase. [Pisum sativum

    Energy Technology Data Exchange (ETDEWEB)

    Salvucci, M.E.; Drake, R.R.; Broadbent, K.P.; Haley, B.E. (Univ. of Kentucky, Lexington (USA)); Hanson, K.R.; McHale, N.A. (Connecticut Agricultural Experiment Station, New Haven, CT (USA))

    1990-05-01

    Phosphorylation of the 64 kilodalton stromal phosphoprotein by incubation of pea (Pisum sativum) chloroplast extracts with ({gamma}-{sup 32}P)ATP decreased in the presence of Glc-6-P and Glc-1,6-P{sub 2}, but was stimulated by glucose. Two-dimensional gel electrophoresis following incubation of intact chloroplasts and stromal extracts with ({gamma}-{sup 32}P)ATP, or incubation of stromal extracts and partially purified phosphoglucomutase (EC 2.7.5.1) with ({sup 32}P)Glc-1-P showed that the identical 64 kilodalton polypeptide was labeled. A 62 kilodalton polypeptide was phosphorylated by incubation of tobacco (Nicotiana sylvestris) stromal extracts with either ({gamma}-{sup 32}P)ATP or ({sup 32}P)Glc-1-P. In contrast, an analogous polypeptide was not phosphorylated in extracts from a tobacco mutant deficient in plastid phosphoglucomutase activity. The results indicate that the 64 (or 62) kilodalton chloroplast stromal phosphoprotein is phosphoglucomutase.

  16. Comparative phloem Mobility of nickel in nonsenescent plants. [Pisum sativa L. ; Pelargonium zonale L

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, P.M.; Chamel, A.

    1986-06-01

    /sup 63/Ni was applied to nonsenescent source leaves and found to be transported to sink tissues in pea (Pisum saativum L.) and geranium plants (Pelargonium zonale L.). The comparative mobilities (percent tracer transported out of source leaf division % /sup 86/Rb transported) for /sup 63/Ni in peas was 2.12 and in geranium 0.25. The value for the phloem mobile /sup 86/Rb was 1.00. By contrast, the comparative mobility of /sup 45/Ca, which is relatively immobile in the phloem, was low (0.05 in peas, 0.00 in geranium). Interruption of the phloem pathway between source and sink leaves by steam girdling almost completely inhibited /sup 63/Ni accumulation in the sink leaves of both species. The authors conclude that Ni is transported from nonsenescent source leaves to sink tissues via the phloem of leguminous and nonleguminous plants.

  17. Organic fertilization alters the community composition of root associated fungi in Pisum sativum

    DEFF Research Database (Denmark)

    Yu, L.; Nicolaisen, M.; Ravnskov, S.;

    2013-01-01

    Organic fertilization is well known to affect individual functional groups of root associated fungi such as arbuscular mycorrhizal (AM) fungi and root pathogens, but limited information is available on the effect of organic fertilization at the fungal community composition level. The main objective...... of the present study was to examine the response of communities of root associated fungi in Pisum sativum to Protamylasse, an organic fertilizer used in pea production. Plants were grown in pots with field soil amended with four different levels of Protamylasse. 454 pyrosequencing was employed to examine......, the organic fertilizer Protamylasse clearly affects communities of root associated fungi, which seems to be linked to the life strategy of the different functional groups of root associated fungi. --------------------------------------------------------------------------------...

  18. Nitrogen deficiency hinders etioplast development in stems of dark-grown pea (Pisum sativum) shoot cultures.

    Science.gov (United States)

    Kósa, Annamária; Preininger, Éva; Böddi, Béla

    2015-11-01

    The effects of nitrogen (N) deprivation were studied in etiolated pea plants (Pisum sativum cv. Zsuzsi) grown in shoot cultures. The average shoot lengths decreased and the stems significantly altered considering their pigment contents, 77 K fluorescence spectra and ultrastructural properties. The protochlorophyllide (Pchlide) content and the relative contribution of the 654-655 nm emitting flash-photoactive Pchlide form significantly decreased. The etioplast inner membrane structure characteristically changed: N deprivation correlated with a decrease in the size and number of prolamellar bodies (PLBs). These results show that N deficiency directly hinders the pigment production, as well as the synthesis of other etioplast inner membrane components in etiolated pea stems.

  19. Photosynthesis and growth responses of pea Pisum sativum L. under heavy metals stress

    Institute of Scientific and Technical Information of China (English)

    Sabrine Hattab; Boutheina Dridi; Lassad Chouba; Mohamed Ben Kheder; Hamadi Bousetta

    2009-01-01

    The present work aims to study the physiological effects of cadmium (Cd) and copper (Cu) in pea (Pisum sativum).Pea plants were exposed to increasing doses of cadmium chloride (CdCl_2) and copper chloride (CuCl_2) for 20 d.The examined parameters,namely root and shoot lengths,the concentration of photosynthetic pigments and the rate of photosynthesis were affected by the treatments especially with high metals concentrations.The analysis of heavy metals accumulation shows that leaves significantly accumulate cadmium for all the tested concentrations.However,copper was significantly accumulated only with the highest tested dose.This may explain the higher inhibitory effects of cadmium on photosynthesis and growth in pea plants.These results are valuable for understanding the biological consequences of heavy metals contamination particularly in soils devoted to organic agriculture.

  20. SSR genetic linkage map construction of pea(Pisum sativum L.) based on Chinese native varieties

    Institute of Scientific and Technical Information of China (English)

    Xuelian; Sun; Tao; Yang; Junjie; Hao; Xiaoyan; Zhang; Rebecca; Ford; Junye; Jiang; Fang; Wang; Jianping; Guan; Xuxiao; Zong

    2014-01-01

    Simple sequence repeat(SSR)markers have previously been applied to linkage mapping of the pea(Pisum sativum L.)genome.However,the transferability of existing loci to the molecularly distinct Chinese winter pea gene pool was limited.A novel set of pea SSR markers was accordingly developed.Together with existing SSR sequences,the genome of the G0003973(winter hardy)×G0005527(cold sensitive)cross was mapped using 190 F2individuals.In total,157 SSR markers were placed in 11 linkage groups with an average interval of 9.7 cM and total coverage of 1518 cM.The novel markers and genetic linkage map will be useful for marker-assisted pea breeding.

  1. [Meiotic abnormalities as expression of nuclear-cytoplasmic incompatibility in crosses of Pisum sativum subspecies].

    Science.gov (United States)

    Bogdanova, V S; Galieva, E R

    2009-05-01

    Meiosis in anthers and mitosis in somatic cells were studied in reciprocal F1 hybrids of the accession VIR320, which belonged to wild Pisum sativum ssp. elatius (Bieb.) Schmal., and the laboratory line Sprint-1. When VIR320 was used as a maternal form, the hybrids displayed nuclear-cytoplasmic conflict, which caused chlorophyll defects and meiotic abnormalities. One or two chromosomes lagged in the equatorial region during chromosome segregation to the poles, distorting cytokinesis and yielding abnormal microspores. Chlorophyll defects were not observed, and meiotic abnormalities were far less frequent in reciprocal hybrids and in the case of an abnormal paternal inheritance of plastids from Sprint-1. Mitosis lacked overt abnormalities in all of the hybrids.

  2. Characterization of the natural enemy community attacking cotton aphid in the Bt cotton ecosystem in Northern China.

    Science.gov (United States)

    Ali, Abid; Desneux, Nicolas; Lu, Yanhui; Liu, Bing; Wu, Kongming

    2016-04-14

    Planting Bt cotton in China since 1997 has led to important changes in the natural enemy communities occurring in cotton, however their specific effect on suppressing the cotton aphids (being notorious in conventional cotton ecosystem) has not been fully documented yet. We observed strong evidence for top-down control of the aphid population, e.g. the control efficiency of natural enemies on cotton aphid increased significantly in open field cages compared to exclusion cages, accounted for 60.2, 87.2 and 76.7% in 2011, 2012 and 2013 season, respectively. The cotton aphid populations peaked in early June to late July (early and middle growth stages) in open field cotton survey from 2011 to 2013. The population densities of cotton aphids and natural enemies were highest on middle growth stage while lowest densities were recorded on late stage for aphids and on early plant stage for natural enemies. Aphid parasitoids (Trioxys spp., Aphidius gifuensis), coccinellids and spiders were key natural enemies of cotton aphid. Briefly, natural enemies can suppress aphid population increase from early to middle plant growth stages by providing biocontrol services in Chinese Bt cotton.

  3. Assessment of patch quality by aphidophagous ladybirds: laboratory study on the minimum density of aphids required for oviposition

    Directory of Open Access Journals (Sweden)

    B. C. Das

    2011-12-01

    Full Text Available Many studies indicate that there is a density of aphids below which ladybirds are unlikely to lay eggs. This is adaptive as theory indicates that a certain minimum population density of aphids is required if hatchling larvae are to survive. The responses of gravid females of the two spot ladybird, Adalia bipunctata (L. (Coleoptera: Coccinellidae, recorded over a period of an hour, to colonies of 5 and 50 pea aphids on bean plants and similar plants each previously infested with the same number of aphids for 48 hours were determined. Proportionally more of the ladybirds on plants with 50 aphids or that were previously infested with the same number of aphids for 48 hours laid eggs and larger clusters of eggs, and were less active than those on plants that were infested with or had previously been infested with five aphids. That is, gravid females showed similar oviposition and activity responses to aphid abundance and different levels of honeydew contamination. This indicates that honeydew contamination may be an important cue used by ladybirds when locating and assessing the abundance of prey in aphid colonies.

  4. Alternaria toxin-induced resistance against rose aphids and olfactory response of aphids to toxin-induced volatiles of rose plants

    Institute of Scientific and Technical Information of China (English)

    Fa-zhong YANG; Li LI; Bin YANG

    2012-01-01

    The search for active toxins for managing weeds or plant diseases is believed to be a promising avenue of investigation.However,the effects of Alternaria toxins on insects have just begun to be investigated.Bioactivities of toxins from four strains of Alternaria alternata on Rosa chinensis and rose aphid Macrosiphum rosivorum were tested in the present study.At a concentration of 50.0 μg/ml,the crude extract (toxin) of strain 7484 was found not to be harmful to rose plants with excised leaf-puncture method (P≥0.079),and rose plants showed enhanced resistance to rose aphids when this Alternaria toxin was sprayed on the plants (P≤0.001).However,this toxin caused no detrimental effects on aphids in insecticidal bioassay at a concentration of 10.0 to 160.0 μg/ml (P≥0.096).Therefore,the Alternaria toxin had significantly induced the resistance of rose plants against rose aphids,demonstrating that the resistance mechanism triggered by the Altemaria toxin in the rose plant may also be used by the plant to defend itself against insects.Further bioassays aimed to discover the olfactory responses of aphids to the toxin-induced volatiles of host plants.The aphids were significantly more attracted to both volatiles emitted and collected from control rose plants than to both volatiles emitted and collected from the toxin-treated rose plants (P≤0.014).This result showed that the toxin-induced resistance related to the volatile changes of host plants.

  5. An annotated checklist of the Aphids (Hemiptera: Aphidomorpha of Poland

    Directory of Open Access Journals (Sweden)

    Wojciechowski Wacław

    2015-12-01

    Full Text Available The paper presents a comprehensive compilation of 764 taxa (species and subspecies, distributed over 167 genera, belonging to 17 subfamilies, three families and three superfamilies of Aphidomorpha recorded to date from Poland. The systematic positions of 19 taxa have been revised in accordance with recent changes in nomenclature. The presence in the Polish aphidofauna of Drepanosiphum oregonensis and Coloradoa huculaki, previously included without any distribution data in checklists of Polish aphids, has been confirmed. One species Sitobion (Sitobion alopecuri is recognized as being new to Poland. At least 44 species (6% of local fauna of Aphidomorpha are alien to Poland; among them 11 species collected from plants imported or cultivated in indoor conditions are listed.

  6. Seasonal phenology and species composition of the aphid fauna in a northern crop production area.

    Directory of Open Access Journals (Sweden)

    Sascha M Kirchner

    Full Text Available BACKGROUND: The species diversity of aphids and seasonal timing of their flight activity can have significant impacts on crop production, as aphid species differ in their ability to transmit plant viruses and flight timing affects virus epidemiology. The aim of the study was to characterise the species composition and phenology of aphid fauna in Finland in one of the northernmost intensive crop production areas of the world (latitude 64°. METHODOLOGY/PRINCIPAL FINDINGS: Flight activity was monitored in four growing seasons (2007-010 using yellow pan traps (YPTs placed in 4-8 seed potato fields and a Rothamsted suction trap. A total of 58,528 winged aphids were obtained, identified to 83 taxa based on morphology, and 34 species were additionally characterised by DNA barcoding. Seasonal flight activity patterns analysed based on YPT catch fell into three main phenology clusters. Monoecious taxa showed early or middle-season flight activity and belonged to species living on shrubs/trees or herbaceous plants, respectively. Heteroecious taxa occurred over the entire potato growing season (ca. 90 days. Abundance of aphids followed a clear 3-year cycle based on suction trap data covering a decade. Rhopalosiphum padi occurring at the end of the potato growing season was the most abundant species. The flight activity of Aphis fabae, the main vector of Potato virus Y in the region, and Aphis gossypii peaked in the beginning of potato growing season. CONCLUSIONS/SIGNIFICANCE: Detailed information was obtained on phenology of a large number aphid species, of which many are agriculturally important pests acting as vectors of plant viruses. Aphis gossypii is known as a pest in greenhouses, but our study shows that it occurs also in the field, even far in the north. The novel information on aphid phenology and ecology has wide implications for prospective pest management, particularly in light of climate change.

  7. Pest control of aphids depends on landscape complexity and natural enemy interactions

    Directory of Open Access Journals (Sweden)

    Emily A. Martin

    2015-07-01

    Full Text Available Aphids are a major concern in agricultural crops worldwide, and control by natural enemies is an essential component of the ecological intensification of agriculture. Although the complexity of agricultural landscapes is known to influence natural enemies of pests, few studies have measured the degree of pest control by different enemy guilds across gradients in landscape complexity. Here, we use multiple natural-enemy exclosures replicated in 18 fields across a gradient in landscape complexity to investigate (1 the strength of natural pest control across landscapes, measured as the difference between pest pressure in the presence and in the absence of natural enemies; (2 the differential contributions of natural enemy guilds to pest control, and the nature of their interactions across landscapes. We show that natural pest control of aphids increased up to six-fold from simple to complex landscapes. In the absence of pest control, aphid population growth was higher in complex than simple landscapes, but was reduced by natural enemies to similar growth rates across all landscapes. The effects of enemy guilds were landscape-dependent. Particularly in complex landscapes, total pest control was supplied by the combined contribution of flying insects and ground-dwellers. Birds had little overall impact on aphid control. Despite evidence for intraguild predation of flying insects by ground-dwellers and birds, the overall effect of enemy guilds on aphid control was complementary. Understanding pest control services at large spatial scales is critical to increase the success of ecological intensification schemes. Our results suggest that, where aphids are the main pest of concern, interactions between natural enemies are largely complementary and lead to a strongly positive effect of landscape complexity on pest control. Increasing the availability of seminatural habitats in agricultural landscapes may thus benefit not only natural enemies, but also the

  8. Pest control of aphids depends on landscape complexity and natural enemy interactions.

    Science.gov (United States)

    Martin, Emily A; Reineking, Björn; Seo, Bumsuk; Steffan-Dewenter, Ingolf

    2015-01-01

    Aphids are a major concern in agricultural crops worldwide, and control by natural enemies is an essential component of the ecological intensification of agriculture. Although the complexity of agricultural landscapes is known to influence natural enemies of pests, few studies have measured the degree of pest control by different enemy guilds across gradients in landscape complexity. Here, we use multiple natural-enemy exclosures replicated in 18 fields across a gradient in landscape complexity to investigate (1) the strength of natural pest control across landscapes, measured as the difference between pest pressure in the presence and in the absence of natural enemies; (2) the differential contributions of natural enemy guilds to pest control, and the nature of their interactions across landscapes. We show that natural pest control of aphids increased up to six-fold from simple to complex landscapes. In the absence of pest control, aphid population growth was higher in complex than simple landscapes, but was reduced by natural enemies to similar growth rates across all landscapes. The effects of enemy guilds were landscape-dependent. Particularly in complex landscapes, total pest control was supplied by the combined contribution of flying insects and ground-dwellers. Birds had little overall impact on aphid control. Despite evidence for intraguild predation of flying insects by ground-dwellers and birds, the overall effect of enemy guilds on aphid control was complementary. Understanding pest control services at large spatial scales is critical to increase the success of ecological intensification schemes. Our results suggest that, where aphids are the main pest of concern, interactions between natural enemies are largely complementary and lead to a strongly positive effect of landscape complexity on pest control. Increasing the availability of seminatural habitats in agricultural landscapes may thus benefit not only natural enemies, but also the effectiveness of

  9. First report of Pandora neoaphidis resting spore formation in vivo in aphid hosts

    DEFF Research Database (Denmark)

    Clara Scorsetti, Ana; Jensen, Annette Bruun; Lopez Lastra, Claudia

    2012-01-01

    The entomopathogenic fungus Pandora neoaphidis is a recognized pathogen of aphids, causes natural epizootics in aphid populations, and interacts and competes with aphid predators and parasitoids. Survival of entomophthoralean fungi in periods of unsuitable weather conditions or lack of appropriate...... is the first gene-based confirmation from either infected hosts or cultures that P. neoaphidis is able to produce resting spores....

  10. [Obtainment of transgenic wheat with the insecticidal lectin from snowdrop (Galanthus nivalis agglutinin; GNA) gene and analysis of resistance to aphid].

    Science.gov (United States)

    Liang, Hui; Zhu, Yin-Feng; Zhu, Zhen; Sun, Dong-Fa; Jia, Xu

    2004-02-01

    Snowdrop lectin (Galanthus nivalis agglutinin; GNA) is toxic to sap sucking injurious insects of Homopteran. A new gna gene has been transferred into common spring wheat Zhong60634 and winter wheat Yumai66 with high yield by using the biolistic transformation method. Transgenic wheat plants have been obtained in both of the two varieties. Two transgenic plants (T0) have been obtained from the bombarded 535 immature embryos of Zhong60634. Bioassay results show that the development of aphid could be slowed down and the survival rate of young aphid could be reduced by gna gene. Seventeen transgenic plants (T0) were obtained from the bombarded 4636 immature embryos of Yumai66. Twenty plantlets with good resistance to Rhopalosiphum padi and Macrosiphum avenae, which are mainly aphid in north wheat area, were identified from the transgenic plants of T1 generation that came from 8 T0 transgenic plants with good resistance to aphid. The anti-aphid bioassay shows that resistance to the different grain aphid is not the same in transgenic wheat plants. To Rhopalosiphum padi, the rate of survival aphid 8 days after exposing transgenic plants to aphids is significantly lower than that of nontransgenic plants. To Macrosiphum avenae, growth speed of aphids is slowed down but not killed. At the same time, the death rate of young aphids is increased. Anyway, feeding of the two kinds of aphids has been controlled in a certain degree by gna gene when aphids can free to move in plants.

  11. Prevalence, Development, and Significance of Ascochyta Blight Caused by Peyronellaea pinodes in Pisum elatius Populations Growing in Natural Ecosystems.

    Science.gov (United States)

    Golani, M; Frenkel, O; Bornstein, M; Shulhani, R; Abbo, S; Shtienberg, D

    2016-08-01

    Wild Pisum populations prevail in Israel in regions with diverse climatic conditions. A comprehensive survey was conducted in the winters of 2007-08 and 2008-09 at two sites in northern Israel, aiming to (i) document the density of Pisum elatius plants in natural ecosystems and elucidate factors related to their initial infection by Ascochyta blight and (ii) determine the factors governing disease development over time on individual plants. The surveyors identified P. elatius plants growing in designated quadrats, inspected each plant visually, and recorded the incidence and severity of its Ascochyta blight symptoms. Ascochyta blight, caused by Peyronellaea pinodes, was ubiquitous in Pisum elatius populations at both survey sites in both seasons. However, the total leaf area exhibiting disease symptoms of individual plants was very low, and stem and pod infections were rarely observed. Based on analyses of the survey data, it was suggested that, in natural ecosystems, the teleomorph stage of Peyronellaea pinodes serves as the main source of the primary and the secondary inoculum of the disease. In addition, it was found that infected leaves dropped off soon after infection, thereby precluding development of stem lesions. The plants continued growing and did not die; thus, they overcame the disease and could be considered "cured". This phenomenon was examined and confirmed in artificially inoculated, potted-plant experiments. It would be worthwhile to exploit the potential of this unique resistance mechanism as a tool for Ascochyta blight management in pea breeding.

  12. Peripheral odour perception by adult aphid forms with the same genotype but different host-plant preferences

    NARCIS (Netherlands)

    Hardie, J.; Visser, J.H.; Piron, P.G.M.

    1995-01-01

    As adults, the summer (alate virginopara) and autumn (gynopara) winged forms of the black bean aphid, Aphis fabae, utilise different host plants, the bean Vicia faba, and the spindle tree, Euonymus europaeus, respectively. Electroantennograms (EAGs) were recorded from the antennae of these aphid for

  13. Using multispectral imagery to compare the spatial pattern of injury to wheat caused by Russian wheat aphid and greenbug

    Science.gov (United States)

    The Russian wheat aphid, Diuraphis noxia (Mordvilko), and greenbug, Schizaphis graminum (Rondani), are important aphid pests of wheat. Outbreaks of both pests in commercial wheat fields occur almost every year in the Great Plains of the United States. Infestations of both pests in wheat fields are...

  14. Biological control of cotton aphid (Aphis gossypii Glover) in cotton (inter)cropping systems in China; a simulation study.

    NARCIS (Netherlands)

    Xia, J.

    1997-01-01

    Cotton aphid ( Aphis gossypii Glover) is the key insect pest of seedling cotton ( Gossypium hirsutum L. ) in China, particularly in the North China cotton region. The resulting annual losses amount to 10-15% of the attainable yield. Sole reliance on insecticides against the cotton aphid in the past

  15. Resistance to a new biotype of the lettuce aphid Nasonovia ribisnigri in Lactuca virosa accession IVT280

    NARCIS (Netherlands)

    Broeke, ten C.J.M.; Dicke, M.; Loon, van J.J.A.

    2013-01-01

    Host plant resistance is an effective protection strategy to control aphids in many crops. However, the evolution of insensitive aphid biotypes necessitates the search for new resistance sources. Wild relatives of crop plants can be important sources for resistance genes to be introgressed into new

  16. Invertebrate communities in spring wheat and the identification of cereal aphid predators through molecular gut content analysis

    Science.gov (United States)

    Cereal aphid complexes are responsible for reducing wheat production worldwide; however, management against these species is rare in North America. Generalist predators may contribute to reducing cereal aphid numbers and preventing significant damage to crops. A two-year survey identifying the arth...

  17. Resistance to lettuce aphid (Nasonovia ribisnigri) biotype 0 in wild lettuce accessions PI 491093 and PI 274378

    Science.gov (United States)

    Lettuce aphid, Nasonovia ribisnigri Mosley (Homoptera : Aphididae), is a major insect pest of lettuce, Lactuca sativa L, in many commercial lettuce productions areas around the world. Resistance to lettuce aphid was first reported in Lactuca virosa L. accession IVT 280 and characterized as complete,...

  18. Assessment of fennel aphids (Hemiptera: Aphididae) and their predators in fennel intercropped with cotton with colored fibers.

    Science.gov (United States)

    Ramalho, F S; Fernandes, F S; Nascimento, A R B; Nascimento Júnior, J L; Malaquias, J B; Silva, C A D

    2012-02-01

    The fennel aphid, Hyadaphis foeniculi (Passerini) (Hemiptera: Aphididae) is a major pest of fennel, Foeniculum vulgare Miller in northeast region of Brazil. We hypothesize that intercropping can be used as an alternative pest management strategy to reduce aphid yield loss in fennel. Thus, we investigated the severity of fennel plant damage in relation to infestation by the fennel aphid and predation by Cycloneda sanguinea (L.) (Coleoptera: Coccinellidae) (spotless lady beetle), green lacewing, Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae), and Scymnus spp. (Coleoptera: Coccinellidae) in sole fennel plots and plots of fennel intercropped with cotton with colored fibers. The fennel aphid populations in nontreated plots were significantly larger in sole fennel plots than in intercropped plots. The highest densities of C. sanguinea, green lacewings and Scymnus spp., associated with the suppression of fennel aphid populations was found in fennel in the intercropping systems. Fennel aphids reduced the fennel seed yield by 80% in the sole fennel plots compared with approximately 30% for all intercropping systems. The results obtained in this research are of practical significance for designing appropriate strategies for fennel aphid control in fennel-cotton intercropping systems. In summary, intercropping fennel with cotton with colored fibers apparently promoted biocontrol of fennel aphid in fennel.

  19. An update to the adventive aphids (Hemiptera: Aphidoidea) of America north of Mexico, with notes on intercepted species

    Science.gov (United States)

    An update to the list of adventive aphids in North America north of Mexico is provided , including the location and date of first discovery, biogeographic origin, and economically important North American hosts for 24 previously unrecorded species. Additionally, we discuss aphids intercepted at Uni...

  20. Effect of Different Aphid I noculation Methods on Aphid Reproduction%不同接蚜方式对烟蚜繁殖效果的影响

    Institute of Scientific and Technical Information of China (English)

    范才银; 张卓; 颜勋锐; 李天艺; 李建华; 黄景崇; 罗井清; 唐海峰; 詹良; 何永秋; 曾惠宇; 安然; 刘亮; 杨会超

    2016-01-01

    利用盆栽成株法、漂浮盘育苗法两种繁蚜方法,研究了挑接法、抹接法、碎片法3种接蚜方式对烟蚜繁蚜效果的影响。结果表明:盆栽成株法繁蚜3种接蚜方式繁蚜速度(繁蚜量)表现为抹接法>碎片法>挑接法;漂浮盘育苗法繁蚜以碎片法接蚜繁蚜效率最好,其次是挑接法,抹接法效果最差。在相同的繁蚜时间里,采用成株法繁蚜的繁蚜量是漂浮盘育苗法的7.85~18.6倍。%The effects of different aphid Inoculation methods on aphid reproduction were studied with planting of potted plant and floating tray seeding methods. The result showed that:when potted planting method was used,the velocity (a-mount)of aphid reproduction was the highest with picking up method,that of wiping off method was the second,and that of fragment method was the third. When floating tray seeding method was used,the velocity (amount)of aphid reproduction was the highest with fragment method,that of picking up method was the second,and that of wiping off method was the third. During the same time of aphid reproduction,the amount of planting of potted plant was 7. 85 -18. 6 times more than that of floating tray seeding method.

  1. Annotated expressed sequence tags and xenobiotic detoxification in the aphid Myzus persicae (Sulzer)

    Institute of Scientific and Technical Information of China (English)

    C.C. FIGUEROA; N. PRUNIER-LETERME; C. RISPE; F. SEPULVEDA; E. FUENTES-CONTRERAS; B. SABATER-MUNOZ; J.-C. SIMON; D. TAGU

    2007-01-01

    Aphids (Hemiptera: Aphididae) are phytophagous insects that are importantagricultural pests. The enormous negative economic impacts caused by aphids worldwide arewell known, and are mostly due to their high multiplication rate and the transmission ofphytopathogenic viruses. Aphid management strategies mainly involve chemical treatmentswhich are pollutants and are increasingly inefficient, since aphids have developed multipleinsecticide-resistant mechanisms. Among the most economically important species is thegreen peach aphid Myzuspersicae Sulzer (Aphididae: Macrosiphini), which is able to colonizea wide range of host plants belonging to many different families, and transmits numerous plantviruses. Because of its large prevalence, M. persicae has been the target of massive insecticidetreatments; consequently, it has evolved several insecticide-resistant mechanisms. In thiswork, a collection of expressed genes from M. persicae is presented in order to identify putativegenes involved in xenobiotic detoxification. After cDNA cloning and sequencing, 959expressed sequence tags (EST) were annotated. Most sequences matched known genescorresponded to metabolism proteins (26%), ribosomal proteins (23%) and structural proteins(8%). Among them, several sequences corresponded to proteins putatively involved in sensing,degradation or detoxification of plant xenobiotic products.

  2. Predation determines different selective pressure on pea aphid host races in a complex agricultural mosaic.

    Directory of Open Access Journals (Sweden)

    Adalbert Balog

    Full Text Available Field assessments were conducted to examine the interplay between host plant and predation in complex agricultural mosaic on pea aphid clover and alfalfa races. In one experiment, we examined the relative fitness on clover race (CR and alfalfa race (AR pea aphids on broad bean, red clover and alfalfa alone. But because clover is typically grown in a more complex agricultural mosaic with alfalfa and broad bean, a second experiment was conducted to assess the fitness consequences under predation in a more complex agricultural field setting that also included potential apparent competition with AR pea aphids. In a third experiment we tested for the effect of differential host race density on the fitness of the other host race mediated by a predator effect. CR pea aphids always had fitness losses when on broad bean (had lower fitness on broad bean relative to red clover and fitness benefits when on red clover (higher fitness on red clover relative to broad bean, whether or not in apparent competition with alfalfa race aphids on bean and alfalfa. AR suffered fitness loss on both alfalfa and bean in apparent competition with CR on clover. Therefore we can conclude that the predation rate between host races was highly asymmetrical. The complexity of the agricultural mosaic thus can influence prey selection by predators on different host plants. These may have evolutionary consequences through context dependent fitness benefits on particular host plants.

  3. Returns to integrated pest management research and outreach for soybean aphid.

    Science.gov (United States)

    Song, Feng; Swinton, Scott M

    2009-12-01

    Soybean aphid, Aphis glycines Matsumura, is a major invasive pest that has caused substantial yield loss and increased insecticide use in the United States since its discovery in 2000. Using the economic surplus approach, we estimate the economic benefits of U.S. research and outreach for integrated pest management (IPM) of soybean aphid. We calculate ex ante net benefits from adoption of an IPM economic threshold (ET). The ET triggers insecticide application only if the value of predicted yield damage from pest scouting is expected to exceed the cost of pest control. Our research finds that gradual adoption of an ET for soybean aphid management will generate a projected economic net benefit of $1.3 billion, for an internal rate of return of 124%, over the 15 yr since soybean aphid IPM research began in 2003. Lower and upper bound sensitivity analysis brackets the estimated net benefit to U.S. consumers and soybean, Glycine max (L.) Merr., growers in the range of $0.6 to $2.6 billion in 2005 dollars. If a 10% rate of return is attributed to IPM applied research and outreach on soybean aphid, that would leave nearly $800 million to compensate prior activities that contribute to the development and adoption of IPM.

  4. Volatiles from Plants Induced by Multiple Aphid Attacks Promote Conidial Performance of Lecanicillium lecanii

    Science.gov (United States)

    Avery, Pasco Bruce; Qasim, Muhammad; Fang, Dalin; Wang, Liande

    2016-01-01

    Herbivore-induced plant volatiles (HIPVs) are clues that help predatory insects search for food. The hypothesis that entomopathogenic fungi, which protect plants, benefit from the release of HIPVs was tested. The plant Arabidopsis thaliana was used as the source of HIPVs. The insect herbivore Lipaphis erysimi (Kaltenbach) was used as the inducer, and the fungal pathogen of the aphid Lecanicillium lecanii was exposed to HIPVs to test our hypothesis. When exposed to aphid-induced A. thaliana volatiles, the mortality of aphids pre-treated with a conidial suspension of L. lecanii, the conidial germination and the appressorial formation were significantly increased compared with the control. The decan-3-ol and 4-methylpentyl isothiocyanate that were detected in the headspace seemed to have positive and negative affection, respectively. Moreover, HIPVs generated from groups of eight aphids per plant promoted significantly increased conidial germination and appressorial formation compared with HIPVs from groups of one, two and four aphids per plant. Our results demonstrated that the pathogenicity of the entomopathogenic fungus L. lecanii was enhanced when exposed to HIPVs and that the HIPVs were affected by the number of insect herbivores that induced them. PMID:26999795

  5. Biological Control of Aphid Using Fungal Culture and Culture Filtrates of Beauveria bassiana.

    Science.gov (United States)

    Kim, Jeong Jun; Jeong, Gayoung; Han, Ji Hee; Lee, Sangyeob

    2013-12-01

    Aphids are one of the most destructive pests in crop production such as pepper, cucumber, and eggplants. The importance of entomopathogenic fungi as alternative pest control agents is increasing. Conidia of entomopathogenic fungi are influenced by environmental conditions, such as temperature and relative humidity, and cause slow and fluctuating mortality. These factors have prevented wider application and use of biocontrol agents. For investigation of means of mitigation of such problems, we conducted bioassays with 47 fungal culture filtrates in order to evaluate the potential of secondary metabolites produced by entomopathogenic fungi for use in aphid control. Among 47 culture filtrates cultured potato dextrose broth, filtrate of Beauveria bassiana Bb08 showed the highest mortality (78%) against green peach aphid three days after treatments. Filtrate of Bb08 cultured in Adamek's medium showed higher toxicity as 100% to third instar nymphs of the aphid compared with seven other filtrates cultured in different broths amended with colloidal chitin or oil. The culture filtrates and fungal cultures from media amended with colloidal chitin or oil had lower control efficacies than filtrates without these additives in three different media. These results indicate that the fungal culture fluid or culture filtrate of B. bassiana Bb08 cultured in Adamek's medium has potential for development as a mycopesticide for aphid control.

  6. Distribution, host plants and natural enemies of sugar beet root aphid (Pemphigus fuscicornis In Slovakia

    Directory of Open Access Journals (Sweden)

    Tóth Peter

    2006-01-01

    Full Text Available During 2003-2004, field surveys were realized to observe the distribution of sugar beet aphid, Pemphigus fuscicornis (K o c h (Sternorrhyncha Pemphigidae in southwestern Slovakia. The research was carried out at 60 different localities with altitudes 112-220 m a. s. l. Sugar beet root aphid was recorded at 30 localities. The aphid was recorded in Slovakia for the first time, but its occurrence was predicted and symptoms and harmfulness overlooked by now. The presence of P. fuscicornis was investigated on roots of various plants from Chenopodiaceae. The most important host plants were various species of lambsquarters (above all Chenopodium album. Furthermore sugar beet (Beta vulgaris provar. altissima, red beet (B. vulgaris provar. conditiva and oraches (Atriplex spp act as host plants. Infestation of sugar beet by P. fuscicornis never exceeded 5% at single locality in Slovakia. Dry and warm weather create presumptions for strong harmfulness. In Slovakia, Chenopodium album is a very important indicator of sugar beet aphid presence allowing evaluation of control requirements. During the study, the larvae of Thaumatomyia glabra (Diptera: Chloropidae were detected as important natural enemies of sugar beet aphid. The species occurred at each location evaluated.

  7. Internode length in Pisum. Gene na may block gibberellin synthesis between ent-7. cap alpha. -hydroxykaurenoic acid and biggerellin A/sub 12/-aldehyde. [Pisum sativum

    Energy Technology Data Exchange (ETDEWEB)

    Ingram, T.J.; Reid, J.B.

    1987-04-01

    The elongation response of the gibberellin (GA) deficient genotypes na, ls, and lh of peas (Pisum sativum L.) to a range of GA-precursors was examined. Plants possessing gene na did not respond to precursors in the GA biosynthetic pathway prior to GA/sub 12/-aldehyde. In contrast, plants possessing lh and ls responded as well as wild-type plants (dwarfed with AMO-1618) to these compounds. The results suggest that GA biosynthesis is blocked prior to ent-kaurene in the lh and ls mutants and between ent-7..cap alpha..-hydroxykaurenoic acid and GA/sub 12/-aldehyde in the na mutant. Feeds of ent(/sup 3/H)kaurenoic acid and (/sup 2/H)GA/sub 12/-aldehyde to a range of genotypes supported the above conclusions. The na line WL1766 was shown by gas chromatography-mass spectrometry (GC-MS) to metabolize(/sup 2/H)GA/sub 12/-aldehyde to a number of (/sup 2/H)C/sub 19/-GAs including GA/sub 1/. However, there was no indication in na genotypes for the metabolism of ent-(/sup 3/H)kaurenoic acid to these GAs. In contrast, the expanding shoot tissue of all Na genotypes examined metabolized ent-(/sup 3/H)kaurenoic acid to radioactive compounds that co-chromatographed with GA/sub 1/, GA/sub 8/, GA/sub 20/, and GA/sub 29/. However, insufficient material was present for unequivocal identification of the metabolites. The radioactive profiles from HPLC of extracts of the node treated with ent-(/sup 3/H)kaurenoic acid were similar for both Na and na plants and contained ent-16..cap alpha..,17-dihydroxykaurenoic acid and ent-6..cap alpha..,7..cap alpha..,16..beta..,17-tetrahydroxykaurenoic acid (both characterized by GC-MS), suggesting that the metabolites arose from side branches of the main GA-biosynthetic pathway. Thus, both Na and na plants appear capable of ent-7..cap alpha..-hydroxylation.

  8. Identification of top-down forces regulating cotton aphid population growth in transgenic Bt cotton in central China.

    Directory of Open Access Journals (Sweden)

    Peng Han

    Full Text Available The cotton aphid Aphis gossypii Glover is the main aphid pest in cotton fields in the Yangtze River Valley Cotton-planting Zone (YRZ in central China. Various natural enemies may attack the cotton aphid in Bt cotton fields but no studies have identified potential specific top-down forces that could help manage this pest in the YRZ in China. In order to identify possibilities for managing the cotton aphid, we monitored cotton aphid population dynamics and identified the effect of natural enemies on cotton aphid population growth using various exclusion cages in transgenic Cry1Ac (Bt+CpTI (Cowpea trypsin inhibitor cotton field in 2011. The aphid population growth in the open field (control was significantly lower than those protected or restricted from exposure to natural enemies in the various exclusion cage types tested. The ladybird predator Propylaea japonica Thunberg represented 65% of Coccinellidae predators, and other predators consisted mainly of syrphids (2.1% and spiders (1.5%. The aphid parasitoids Aphidiines represented 76.7% of the total count of the natural enemy guild (mainly Lysiphlebia japonica Ashmead and Binodoxys indicus Subba Rao & Sharma. Our results showed that P. japonica can effectively delay the establishment and subsequent population growth of aphids during the cotton growing season. Aphidiines could also reduce aphid density although their impact may be shadowed by the presence of coccinellids in the open field (likely both owing to resource competition and intraguild predation. The implications of these results are discussed in a framework of the compatibility of transgenic crops and top-down forces exerted by natural enemy guild.

  9. Identification of top-down forces regulating cotton aphid population growth in transgenic Bt cotton in central China.

    Science.gov (United States)

    Han, Peng; Niu, Chang-ying; Desneux, Nicolas

    2014-01-01

    The cotton aphid Aphis gossypii Glover is the main aphid pest in cotton fields in the Yangtze River Valley Cotton-planting Zone (YRZ) in central China. Various natural enemies may attack the cotton aphid in Bt cotton fields but no studies have identified potential specific top-down forces that could help manage this pest in the YRZ in China. In order to identify possibilities for managing the cotton aphid, we monitored cotton aphid population dynamics and identified the effect of natural enemies on cotton aphid population growth using various exclusion cages in transgenic Cry1Ac (Bt)+CpTI (Cowpea trypsin inhibitor) cotton field in 2011. The aphid population growth in the open field (control) was significantly lower than those protected or restricted from exposure to natural enemies in the various exclusion cage types tested. The ladybird predator Propylaea japonica Thunberg represented 65% of Coccinellidae predators, and other predators consisted mainly of syrphids (2.1%) and spiders (1.5%). The aphid parasitoids Aphidiines represented 76.7% of the total count of the natural enemy guild (mainly Lysiphlebia japonica Ashmead and Binodoxys indicus Subba Rao & Sharma). Our results showed that P. japonica can effectively delay the establishment and subsequent population growth of aphids during the cotton growing season. Aphidiines could also reduce aphid density although their impact may be shadowed by the presence of coccinellids in the open field (likely both owing to resource competition and intraguild predation). The implications of these results are discussed in a framework of the compatibility of transgenic crops and top-down forces exerted by natural enemy guild.

  10. Host Plant Volatiles and the Sexual Reproduction of the Potato Aphid, Macrosiphum euphorbiae

    Directory of Open Access Journals (Sweden)

    Jessica Hurley

    2014-10-01

    Full Text Available In late summer, heteroecious aphids, such as the potato aphid, Macrosiphum euphorbiae, move from their secondary summer host plants to primary host plants, where the sexual oviparae mate and lay diapausing eggs. We tested the hypothesis that volatiles of the primary host, Rosa rugosa, would attract the gynoparae, the parthenogenetic alate morph that produce oviparae, as well as the alate males foraging for suitable mates. In wind tunnel assays, both gynoparae and males oriented towards and reached rose cuttings significantly more often than other odour sources, including potato, a major secondary host. The response of males was as high to rose cuttings alone as to potato with a calling virgin oviparous female. These findings are discussed within the seasonal ecology of host alternating aphids.

  11. Wheat Nitrogen Fertilisation Effects on the Performance of the Cereal Aphid Metopolophium dirhodum

    Directory of Open Access Journals (Sweden)

    Alan F. J. Gash

    2012-02-01

    Full Text Available The effects of five rates of nitrogen fertiliser applications on the performance of the cereal aphid Metopolophium dirhodum on winter wheat, within the range of rates recommended for UK crops, were investigated over two seasons in field-grown crops and also on plants grown in the glasshouse. Longevity was unaffected by the level of fertilisation, but aphid intrinsic rate of increase and fecundity increased with each level applied. In the second field season, when a higher upper limit was used, many of these increases were significant. A previously unreported finding for this species was that there was a significant decrease in fecundity for the highest rate of fertilisation. Results for the glasshouse-reared aphids followed a similar pattern to those in the field, and overall they underline recent reports in the literature of the negative effects of high nutrient concentrations on the performance of herbivorous insects. The underlying reasons for these are discussed.

  12. Trophic interactions between rhizosphere bacteria and bacterial feeders influenced by phosphate and aphids in barley

    DEFF Research Database (Denmark)

    Strandmark, Lisa Bjørnlund; Mørk, Søren; Madsen, Mette Vestergård;

    2006-01-01

    The aim was to study the effects of P fertilization and leaf aphid attack on the trophic interactions of bacteria and bacterial feeders in the rhizospheres of barley plants. The density of protozoa peaked in the rhizospheres of plants fertilized with N and P, whereas nematodes peaked in the rhizo......The aim was to study the effects of P fertilization and leaf aphid attack on the trophic interactions of bacteria and bacterial feeders in the rhizospheres of barley plants. The density of protozoa peaked in the rhizospheres of plants fertilized with N and P, whereas nematodes peaked...... in the rhizospheres of plants to which only N had been added. Fingerprinting of bacterial communities by length heterogeneity polymerase chain reaction revealed differences in community structure between NP rhizospheres and N rhizospheres as well as aphid-related differences within N rhizospheres. Specifically, a...

  13. The endosymbiont Arsenophonus is widespread in soybean aphid, Aphis glycines, but does not provide protection from parasitoids or a fungal pathogen.

    Directory of Open Access Journals (Sweden)

    Jason A Wulff

    Full Text Available Aphids commonly harbor bacterial facultative symbionts that have a variety of effects upon their aphid hosts, including defense against hymenopteran parasitoids and fungal pathogens. The soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae, is infected with the symbiont Arsenophonus sp., which has an unknown role in its aphid host. Our research goals were to document the infection frequency and diversity of the symbiont in field-collected soybean aphids, and to determine whether Arsenophonus is defending soybean aphid against natural enemies. We performed diagnostic PCR and sequenced four Arsenophonus genes in soybean aphids from their native and introduced range to estimate infection frequency and genetic diversity, and found that Arsenophonus infection is highly prevalent and genetically uniform. To evaluate the defensive role of Arsenophonus, we cured two aphid genotypes of their natural Arsenophonus infection through ampicillin microinjection, resulting in infected and uninfected isolines within the same genetic background. These isolines were subjected to parasitoid assays using a recently introduced biological control agent, Binodoxys communis [Braconidae], a naturally recruited parasitoid, Aphelinus certus [Aphelinidae], and a commercially available biological control agent, Aphidius colemani [Braconidae]. We also assayed the effect of the common aphid fungal pathogen, Pandora neoaphidis (Remaudiere & Hennebert Humber (Entomophthorales: Entomophthoraceae, on the same aphid isolines. We did not find differences in successful parasitism for any of the parasitoid species, nor did we find differences in P. neoaphidis infection between our treatments. Our conclusion is that Arsenophonus does not defend its soybean aphid host against these major parasitoid and fungal natural enemies.

  14. Pre-fractionation strategies to resolve pea (Pisum sativum) sub-proteomes

    Science.gov (United States)

    Meisrimler, Claudia-Nicole; Menckhoff, Ljiljana; Kukavica, Biljana M.; Lüthje, Sabine

    2015-01-01

    Legumes are important crop plants and pea (Pisum sativum L.) has been investigated as a model with respect to several physiological aspects. The sequencing of the pea genome has not been completed. Therefore, proteomic approaches are currently limited. Nevertheless, the increasing numbers of available EST-databases as well as the high homology of the pea and medicago genome (Medicago truncatula Gaertner) allow the successful identification of proteins. Due to the un-sequenced pea genome, pre-fractionation approaches have been used in pea proteomic surveys in the past. Aside from a number of selective proteome studies on crude extracts and the chloroplast, few studies have targeted other components such as the pea secretome, an important sub-proteome of interest due to its role in abiotic and biotic stress processes. The secretome itself can be further divided into different sub-proteomes (plasma membrane, apoplast, cell wall proteins). Cell fractionation in combination with different gel-electrophoresis, chromatography methods and protein identification by mass spectrometry are important partners to gain insight into pea sub-proteomes, post-translational modifications and protein functions. Overall, pea proteomics needs to link numerous existing physiological and biochemical data to gain further insight into adaptation processes, which play important roles in field applications. Future developments and directions in pea proteomics are discussed. PMID:26539198

  15. Pre-fractionation strategies to resolve pea (Pisum sativum sub-proteomes

    Directory of Open Access Journals (Sweden)

    Claudia Nicole Meisrimler

    2015-10-01

    Full Text Available Legumes are important crop plants and pea (Pisum sativum L. has been investigated as a model with respect to several physiological aspects. The sequencing of the pea genome has not been completed. Therefore, proteomic approaches are currently limited. Nevertheless, the increasing numbers of available EST-databases as well as the high homology of the pea and medicago genome (Medicago truncatula G. allow the successful identification of proteins. Due to the un-sequenced pea genome, pre-fractionation approaches have been used in pea proteomic surveys in the past. Aside from a number of selective proteome studies on crude extracts and the chloroplast, few studies have targeted other components such as the pea secretome, an important sub-proteome of interest due to its role in abiotic and biotic stress processes. The secretome itself can be further divided into different sub-proteomes (plasma membrane, apoplast, cell wall proteins. Cell fractionation in combination with different gel-electrophoresis, chromatography methods and protein identification by mass spectrometry are important partners to gain insight into pea sub-proteomes, post-translational modifications and protein functions. Overall, pea proteomics needs to link numerous existing physiological and biochemical data to gain further insight into adaptation processes, which play important roles in field applications. Future developments and directions in pea proteomics are discussed.

  16. Comportement agronomique d'une collection de pois (Pisum sativum L

    Directory of Open Access Journals (Sweden)

    Bouslama, M.

    2007-01-01

    Full Text Available Agronomical Behaviour of a Pea Collection (Pisum sativum L.. This experience was achieved under greenhouse conditions. Twelve genotypes of pea were used (Asgrow, Jumbo, Lincoln, Merveille de Kelvedon, Purser, Rajai Torpe, Snajor Kosep, Korai,Wando, Rondo, local genotype, Major Kosep Korai and Surgevil. They were cultivated on peat during 5.5 months (from October to April. Some agronomical parameters were studied: resistance to diseases, (Powdery-mildew, mildew, top yellow virus, anthracnose, browning, fresh matter, number of branches/plant, number of flowers/plant, number of pods/ plant and the yield of grains /plant. Results showed that only the genotype Purser is resistant to all diseases and Surgevil is sensitive only to the Top Yellow virus. The local genotype is sensitive to three frequent diseases (Powdery-mildew, mildew and Anthracnose. With regard to vegetative growth, the highest yield of fresh matter do not contribute towards a high fertility rate. In fact, only the genotypes having a weak yield of fresh matter (Snajor Kosep Korai, Asgrow, Major Kosep Korai, Rajai Torpe and Purser have the most important rate of fertility (> 30%. Within this group, the most important yield (> 9 g/plant is a result of high: number of pods/plant (7.5 to 21.6 and of grains/pod (2.8 to 4.92. Finally, genotype Purser should be retained for farmers and programs of genetic amelioration for its resistance to diseases and agronomical performances.

  17. Studies on antioxidative enzymes induced by cadmium in pea plants (Pisum sativum).

    Science.gov (United States)

    Pandey, Nalini; Singh, Gaurav Kumar

    2012-03-01

    Pea plants (Pisum sativum cv. Swati) exposed to different concentration of cadmium (50,100, 200 microM Cd) under controlled glass house conditions were quantified for different physiological parameters and antioxidative enzymes. In pea plants, Cd produced a significant inhibition of growth and induced chlorosis, marginal yellowing and necrosis in young leaves, the effect being most pronounced at 200 microM Cd supply. An alteration in the activated oxygen metabolism of pea plants were also detected as evidenced by an increase in concentration of H2O2 and TBARS along with decrease in the chlorophyll and carotenoid concentration in leaves. Cadmium toxicity induced an increase in non-protein thiol, ascorbate, proline and cysteine concentration. A significant increment in the activity of SOD, APX and GR, and a decrease in CAT was observed as a result of Cd treatment. The enhanced activity of SOD and inhibition of CAT and POD produces a high build up of H2O2 which appears to be the main cause of oxidative stress due to Cd toxicity in pea plants.

  18. Evaluation of genetic divergence and heritability in pea (Pisum sativum L.

    Directory of Open Access Journals (Sweden)

    Natalia Georgieva

    2016-04-01

    Full Text Available An experiment on genetic evaluation of five genotypes of forage pea (Glyans, Svit, Kamerton, Modus, Pleven 4 was conducted during 2012-2014 period. Analysis of variance showed significant differences among genotypes for the traits pod width, seeds per plant, seed weight per plant and 1000 seed weight. The estimates of genetic parameters of five varieties of Pisum sativum L. indicated a good amount of genetic variation in the experimental materials under investigation. Moderate phenotypic and genotypic coefficients of variation were observed for most of traits except pod length and pod width. For the traits studied seeds per plant, seed weight per plant and plant height were found high heritability along with high genetic gain indicating preponderance of additive effects. Therefore, selection programme based on these characters would be more effective in improving yield parameters of forage pea. The seed yield was positively and significantly correlated with 1000 seed weight and pod stem, which suggested the possibilities of improving seed yield by simultaneous improvement of these traits.

  19. Changes in free polyamines and related enzymes during stipule and pod wall development in Pisum sativum.

    Science.gov (United States)

    Chattopadhyay, Soumen; Lahiri, Kajari; Bharati, Ghosh

    2002-08-01

    Level of free polyamines, their key metabolic enzymes, and other features related to ageing were examined during stipule and pod wall development in pea (Pisum sativum). Free polyamine titre (per unit fresh mass) in both the organs, the specific activities of arginine decarboxylase and ornithine decarboxylase in the pod wall, gradually decreased with maturation. In stipule, these enzymes attained peak activity at 15 days after pod emergence and declined thereafter. Ornithine decarboxylase activity was greater in pod wall than in stipule; while, arginine decarboxylase activity was higher in stipule. Activity of degradative enzyme diamine oxidase increased with the onset of senescence in both the organs. Chlorophyll and electrical conductance had a inverse relationship throughout the experimental period, whereas, the chlorophyll content was directly related with polyamine levels in both stipule and pod wall during aging. On the other hand, protein and RNA contents were positively correlated with free polyamines throughout the test period in stipule, but in the pod wall this was true only for the later stages of development.

  20. Development and Characterization of 37 Novel EST-SSR Markers in Pisum sativum (Fabaceae

    Directory of Open Access Journals (Sweden)

    Xiaofeng Zhuang

    2013-01-01

    Full Text Available Premise of the study: Simple sequence repeat markers were developed based on expressed sequence tags (EST-SSR and screened for polymorphism among 23 Pisum sativum individuals to assist development and refinement of pea linkage maps. In particular, the SSR markers were developed to assist in mapping of white mold disease resistance quantitative trait loci. Methods and Results: Primer pairs were designed for 46 SSRs identified in EST contiguous sequences assembled from a 454 pyrosequenced transcriptome of the pea cultivar, ‘LIFTER’. Thirty-seven SSR markers amplified PCR products, of which 11 (30% SSR markers produced polymorphism in 23 individuals, including parents of recombinant inbred lines, with two to four alleles. The observed and expected heterozygosities ranged from 0 to 0.43 and from 0.31 to 0.83, respectively. Conclusions: These EST-SSR markers for pea will be useful for refinement of pea linkage maps, and will likely be useful for comparative mapping of pea and as tools for marker-based pea breeding.

  1. Effect of Pisum sativum as protein supplement on buffalo milk production

    Directory of Open Access Journals (Sweden)

    C. Grassi

    2010-02-01

    Full Text Available A study was carried out at an organic buffalo dairy farm in order to investigate the effect of feeding protein peas (Pisum sativum L. as an alternative protein source for buffalo cow diets. Two concentrates were formulated to contain (as fed basis either 350 g/kg of soybean cake (SC or 450 g/kg of peas (PC as the main protein sources. The two concentrates were formulated to be almost isonitrogenous (on average crude protein 240 g/kg DM. Two groups of 10 buffalo cows were used in a 100-day lactation study (from 10 days in milk onwards. Cows were blocked into two groups according to lactation number and previous milk yield and were assigned to one of two dietary treatments: control group was offered in the milking parlour 3 kg of SC, while treatment group was offered the same quantity of PC. All cows were fed a total mixed ration containing 3 kg of SC. Daily milk yield was not affected by treatment, as well as, milk fat and protein percentages, somatic cell count, urea content and fatty acid composition.

  2. Isozymes of beta-N-Acetylhexosaminidase from Pea Seeds (Pisum sativum L.).

    Science.gov (United States)

    Harley, S M; Beevers, L

    1987-12-01

    Four isozymes of beta-N-acetylhexosaminidase (beta-NAHA) from pea seeds (Pisum sativum L.) have been separated, with one, designated beta-NAHA-II, purified to apparent homogeneity by means of an affinity column constructed by ligating p-aminophenyl-N-acetyl-beta-d-thioglucosaminide to Affi-Gel 202. The other three isozymes have been separated and purified 500- to 1750-fold by chromatography on Concanavalin A-Sepharose, Zn(2+) charged immobilized metal affinity chromatography, hydrophobic chromatography, and ion exchange chromatography on CM-Sephadex. All four isozymes are located in the protein bodies of the cotyledons. The molecular weight of each isozyme is 210,000. beta-NAHA-II is composed of two heterogenous subunits. The subunits are not held together by disulfide bonds, but sulfhydryl groups are important for catalysis. All four isozymes release p-nitrophenol from both p-nitrophenyl-N-acetyl-beta-d-glucosaminide and p-nitrophenyl-N-acetyl-beta-d-galactosaminide. The ratio of activity for hydrolysis of the two substrates is pH dependent. The K(m) value for the two substrates and pH optima of the isozymes are comparable to beta-NAHAs from other plant sources.

  3. Pb2+ exposure induced microsatellite instability in Pisum sativum in a locus related with glutamine metabolism.

    Science.gov (United States)

    Rodriguez, E; Azevedo, R; Moreira, H; Souto, L; Santos, Conceição

    2013-01-01

    Lead (Pb) is a toxic element, but its putative mutagenic effects in plant cells, using molecular markers, remain to unveil. To evaluate if Pb induces mutagenicity, Pisum sativum L. seedlings were exposed to Pb(2+) (up to 2000 mg L(-1)) for 28 days and the instability of microsatellites (or Simple Sequence Repeats, SSR) was analyzed in leaves and roots. The analysis of eight selected microsatellites (SSR1-SSR8) demonstrated that only at the highest dosage microsatellite instability (MSI) occurred, at a frequency of 4.2%. Changes were detected in one microsatellite (SSR6) that is inserted in the locus for glutamine synthetase. SSR6 products of roots exposed to the highest concentration of Pb were 3 bp larger than those of the control. Our data demonstrate that: (a) SSR technique is sensitive to detect Pb-induced mutagenicity in plants. MSI instability is Pb dose dependent and organ dependent (roots are more sensitive); (b) the Pb-sensitive SSR6 is inserted in the glutamine synthetase locus, with still unknown relation with functional changes of this enzyme; (c) Pb levels inducing MSI are much above the maximum admitted levels in some European Union countries for agricultural purpose waters. In conclusion, we propose here the potential use of SSR to evaluate Pb(2+)-induced mutagenicity, in combination with other genetic markers.

  4. De Novo Assembly of the Pea (Pisum sativum L. Nodule Transcriptome

    Directory of Open Access Journals (Sweden)

    Vladimir A. Zhukov

    2015-01-01

    Full Text Available The large size and complexity of the garden pea (Pisum sativum L. genome hamper its sequencing and the discovery of pea gene resources. Although transcriptome sequencing provides extensive information about expressed genes, some tissue-specific transcripts can only be identified from particular organs under appropriate conditions. In this study, we performed RNA sequencing of polyadenylated transcripts from young pea nodules and root tips on an Illumina GAIIx system, followed by de novo transcriptome assembly using the Trinity program. We obtained more than 58,000 and 37,000 contigs from “Nodules” and “Root Tips” assemblies, respectively. The quality of the assemblies was assessed by comparison with pea expressed sequence tags and transcriptome sequencing project data available from NCBI website. The “Nodules” assembly was compared with the “Root Tips” assembly and with pea transcriptome sequencing data from projects indicating tissue specificity. As a result, approximately 13,000 nodule-specific contigs were found and annotated by alignment to known plant protein-coding sequences and by Gene Ontology searching. Of these, 581 sequences were found to possess full CDSs and could thus be considered as novel nodule-specific transcripts of pea. The information about pea nodule-specific gene sequences can be applied for gene-based markers creation, polymorphism studies, and real-time PCR.

  5. Role of LLD, a new locus for leaflet/pinna morphogenesis in Pisum sativum

    Indian Academy of Sciences (India)

    Seema Prajapati; Sushil Kumar

    2001-12-01

    Properties of a mutant at the LLD (LEAF-LET DEVELOPMENT) locus in pea Pisum sativum L. are reported in this paper. Plants homozygous for the Mendelian recessive mutation lld bear leaves in which a few to many leaflets are incompletely developed. Opposite pinnae of rachis nodes often formed fused incompletely developed leaflets. The lld mutation was observed to abort pinna development at almost all morphogenetic stages. The lld mutation demonstrated high penetrance and low expressivity. The phenotypes of lld plants in tl, tac, tl tac, tl af and tl af tac backgrounds suggested that LLD function is involved in the separation of lateral adjacent blastozones differentiated on primary, secondary and tertiary rachides and lamina development in leaflets. The aborted development of tendrils and leaflets in lld mutants was related to deficiency in vascular tissue growth. The morphological and anatomical features of the leaflets formed on a tl lld double mutant permitted a model of basipetal leaflet development. The key steps of leaflet morphogenesis include origin of the lamina by splitting of a radially symmetrical growing pinna having abaxial outer surface, opposite to the vascular cylinder, through an invaginational groove, differentiation of adaxial surface along the outer boundary of split tissue in the groove and expansion of the lamina ridges so formed into lamina spans.

  6. Purification and Characterization of a Lectin from Green Split Peas (Pisum sativum).

    Science.gov (United States)

    Ng, Tzi Bun; Chan, Yau Sang; Ng, Charlene Cheuk Wing; Wong, Jack Ho

    2015-11-01

    Lectins have captured the attention of a large number of researchers on account of their various exploitable activities, including antitumor, immunomodulatory, antifungal, as well as HIV reverse transcriptase inhibitory activities. A mannose/glucose-specific lectin was isolated from green split peas (a variety of Pisum sativum) and characterized. The purification step involved anion-exchange chromatography on a DEAE-cellulose column, cation-exchange chromatography on an SP-Sepharose column, and gel filtration by fast protein liquid chromatography (FPLC) on Superdex 200. The purified lectin had a native molecular mass of around 50 kDa as determined by size exclusion chromatography. It appeared as a heterotetramer, composed of two distinct polypeptide bands with a molecular mass of 6 and 19 kDa, respectively, in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The N-terminal sequence of green split pea lectin shows some degree of homology compared to lectins from other legume species. Its hemagglutinating activity was inhibited by glucose, mannose, and sucrose, and attenuated at pH values higher than 12 or lower than 3. Hemagglutinating activity was preserved at temperatures lower than 80 °C. The lectin did not show antifungal activity toward fungi including Fusarium oxysporum, Botrytis cinerea, and Mycosphaerella arachidicola. Green split pea lectin showed a mitogenic effect toward murine splenocytes and could inhibit the activity of HIV-1 reverse transcriptase.

  7. Study of DC and AC electric field effect on Pisum sativum seeds growth

    Science.gov (United States)

    Mahmood, Bahar; Jaleh, Sojoodi; Yasaman, Yasaie

    2014-07-01

    In this research the effect of electric field on two groups of wet and dry Pisum sativum seeds growth was studied. To generate the required electric field a parallel-plate capacitor with round copper plates of 30 cm diameter was used. The experiments were performed once in fixed exposure duration of 8 min in variable DC electric field of 0.25-1.5 kV/m. The other experiments were performed in variable fields of 50-125 kV/m in fixed exposure duration of 8 min, in two groups of AC and DC electric fields. The experiments were repeated three times. In each experiment 10 seeds were used and there was a sham exposed group for comparison, too. After application of electric field, the seeds were kept for six days in the same growth chamber with the temperature of 25 ± 1 °C and 12 h light/12 h darkness. On the 6th day length of stems and height of roots were measured. After doing statistical analysis, in low intensities of DC electric field, the highest significant increase of mean growth (The average of stem length and the height of roots) was seen in 1.5 kV/m in wet seeds. In high intensities of DC and AC electric fields, the highest significant increase of mean growth was seen in AC electric field of 100 kV/m in wet seeds.

  8. Genetic interaction and mapping studies on the leaflet development (lld) mutant in Pisum sativum

    Indian Academy of Sciences (India)

    Sushil Kumar; Raghvendra Kumar Mishra; Arvind Kumar; Swati Chaudhary; Vishakha Sharma; Renu Kumari

    2012-12-01

    In Pisum sativum, the completely penetrant leaflet development (lld) mutation is known to sporadically abort pinnae suborgans in the unipinnate compound leaf. Here, the frequency and morphology of abortion was studied in each of the leaf suborgans in 36 genotypes and in presence of auxin and gibberellin, and their antagonists. Various lld genotypes were constructed by multifariously recombining lld with a coch homeotic stipule mutation and with af, ins, mare, mfp, tl and uni-tac leaf morphology mutations. It was observed that the suborgans at all levels of pinna subdivisions underwent lld-led abortion events at different stages of development. As in leafblades, lld aborted the pinnae in leaf-like compound coch stipules. The lld mutation interacted with mfp synergistically and with other leaf mutations additively. The rod-shaped and trumpet-shaped aborted pea leaf suborgans mimicked the phenotype of aborted leaves in HD-ZIP-III-deficient Arabidopsis thaliana mutants. Suborganwise aborted morphologies in lld gnotypes were in agreement with basipetal differentiation of leaflets and acropetal differentiation in tendrils. Altogether, the observations suggested that LLD was the master regulator of pinna development. On the basis of molecular markers found linked to lld, its locus was positioned on the linkage group III of the P. sativum genetic map.

  9. Immunocytochemical localization of Pisum sativum TRXs f and m in non-photosynthetic tissues.

    Science.gov (United States)

    Traverso, José A; Vignols, Florence; Cazalis, Roland; Serrato, Antonio J; Pulido, Pablo; Sahrawy, Mariam; Meyer, Yves; Cejudo, Francisco Javier; Chueca, Ana

    2008-01-01

    Plants are the organisms containing the most complex multigenic family for thioredoxins (TRX). Several types of TRXs are targeted to chloroplasts, which have been classified into four subgroups: m, f, x, and y. Among them, TRXs f and m were the first plastidial TRXs characterized, and their function as redox modulators of enzymes involved in carbon assimilation in the chloroplast has been well-established. Both TRXs, f and m, were named according to their ability to reduce plastidial fructose-1,6-bisphosphatase (FBPase) and malate dehydrogenase (MDH), respectively. Evidence is presented here based on the immunocytochemistry of the localization of f and m-type TRXs from Pisum sativum in non-photosynthetic tissues. Both TRXs showed a different spatial pattern. Whilst PsTRXm was localized to vascular tissues of all the organs analysed (leaves, stems, and roots), PsTRXf was localized to more specific cells next to xylem vessels and vascular cambium. Heterologous complementation analysis of the yeast mutant EMY63, deficient in both yeast TRXs, by the pea plastidial TRXs suggests that PsTRXm, but not PsTRXf, is involved in the mechanism of reactive oxygen species (ROS) detoxification. In agreement with this function, the PsTRXm gene was induced in roots of pea plants in response to hydrogen peroxide.

  10. Silencing of Two Insulin Receptor Genes Disrupts Nymph-Adult Transition of Alate Brown Citrus Aphid

    Science.gov (United States)

    Ding, Bi-Yue; Shang, Feng; Zhang, Qiang; Xiong, Ying; Yang, Qun; Niu, Jin-Zhi; Smagghe, Guy; Wang, Jin-Jun

    2017-01-01

    Insulin receptors play key roles in growth, development, and polymorphism in insects. Here, we report two insulin receptor genes (AcInR1 and AcInR2) from the brown citrus aphid, Aphis (Toxoptera) citricidus. Transcriptional analyses showed that AcInR1 increased during the nymph–adult transition in alate aphids, while AcInR2 had the highest expression level in second instar nymphs. AcInR1 is important in aphid development from fourth instar nymphs to adults as verified by dsRNA feeding mediated RNAi. The silencing of AcInR1 or/and AcInR2 produced a variety of phenotypes including adults with normal wings, malformed wings, under-developed wings, and aphids failing to develop beyond the nymphal stages. Silencing of AcInR1 or AcInR2 alone, and co-silencing of both genes, resulted in 73% or 60%, and 87% of aphids with problems in the transition from nymph to normal adult. The co-silencing of AcInR1 and AcInR2 resulted in 62% dead nymphs, but no mortality occurred by silencing of AcInR1 or AcInR2 alone. Phenotypes of adults in the dsInR1 and dsInR2 were similar. The results demonstrate that AcInR1 and AcInR2 are essential for successful nymph–adult transition in alate aphids and show that RNAi methods may be useful for the management of this pest. PMID:28230772

  11. Increased Susceptibility to Aphids of Flowering Wheat Plants Exposed to Low Temperatures.

    Science.gov (United States)

    Lacoste, C; Nansen, C; Thompson, S; Moir-Barnetson, L; Mian, A; McNee, M; Flower, K C

    2015-06-01

    Frost is known to directly affect flowering wheat plants (Triticum aestivum L.) and lead to reduced grain yield. Additionally, it may increase wheat susceptibility to economically important pests, such as aphids (Hemiptera: Aphididae). Wheat plants at flowering stage were exposed to one of the three temperature treatments: ambient (11-12°C), 0°C, and -3°C for 60 min. Preference (3-choice) and performance (no-choice) bioassays with aphids (Rhopalosiphum padi L.) were conducted 1, 3, 6, and 12 d after temperature treatments to assess effects of temperature-induced stress over time. As an initial feasibility study of using remote sensing technologies to detect frost-induced stress in flowering wheat plants, hyperspectral imaging data were acquired from wheat plants used in preference bioassays. Element analysis of wheat plants was included to determine the effect of temperature-induced stress on the nutritional composition of flowering wheat plants. The results from this study support the following cause-effect scenario: a 60-min exposure to low temperatures caused a significant decrease in potassium and copper content of wheat plants 6 d after temperature exposure, and it coincided with a marked increase in preference by aphids of wheat plants. The preference exhibited by aphids correlated positively with performance of aphids, so the preference-performance hypothesis was confirmed and possibly driven by potassium and copper content of wheat plants. In addition, we demonstrated that hyperspectral imaging data can be used to detect frost-induced susceptibility to aphid infestation in flowering wheat plants. These findings justify further research into airborne remote sensing of frost-induced stress and the possible secondary effects on crop susceptibility to arthropod pests.

  12. Role of terpenes from aphid-infested potato on searching and oviposition behavior of Episyrphus balteatus

    Institute of Scientific and Technical Information of China (English)

    NICOLAS HARMEL; RAKI ALMOHAMAD; MARIE-LAURE FAUCONNIER; PATRICK DU JARDIN; FRANCO IS VERHEGGEN; MICHEL MARLIER; ERIC HAUBRUGE; FR(E)D(E)RIC FRANCIS

    2007-01-01

    To cope with pathogen and insect attacks, plants develop different mechanismsof defence, in both direct (physical and chemical) and indirect ways (attractive volatiles toentomophagous beneficials). Plants are then able to express traits that facilitate "top-down"control of pests by attracting herbivore predators. Here we investigate the indirect defencemechanism of potato plants by analyzing the volatile patterns of both healthy and aphidinfested plants. Important changes in the emitted terpene pattern by the Myzus persicaeinfested host plant were observed. Using Solid Phase MicroExtraction (SPME) and GC-MS,the (E)-β-farnesene (EBF) appeared to be emitted by aphid-infested potato and not byhealthy plants. To assess the infochemical role of these volatile releases after aphid damageon the aphidophagous predators Episyrphus balteatus, the hoverfly foraging behavior wasassessed using the Observer 5.0 software (Noldus, Wageningen, The Netherlands). Aphidfree potato plants were also used as a control volatile source in the predator behavioral study.While aphid-infested plants induced efficient searching and acceptation behaviors leadingto egg-laying, no kairomonal effect of healthy potato plants was observed, leading to longerimmobility durations and shorter searching periods in the net cage. High oviposition rate ofE. balteatus was observed when aphid-infested potato was used (mean of 48.9 eggs perlaying and per female). On the other hand, no egg was produced by the hoverfly on healthyaphid-free plants. The E. balteatus foraging and reproductive behaviors according to thevolatile emission from aphid-infested plants are discussed in relation to the potential use ofactive infochemical molecules in integrated aphid pest management.

  13. Natural enemies act faster than endophytic fungi in population control of cereal aphids.

    Science.gov (United States)

    Härri, Simone A; Krauss, Jochen; Müller, Christine B

    2008-05-01

    1. Fast-growing populations of phytophagous insects can be limited by the presence of natural enemies and by alkaloids that are produced by symbiotic associations of many temperate grass species with endophytic fungi. It is unclear if and how acquired plant defences derived from endophytic fungi interact with natural enemies to affect phytophagous insect populations. 2. To assess the relative importance of endophytic fungi compared to that of natural enemies on the population dynamics of phytophagous insects, we carried out a fully factorial field experiment, in which the presence of natural enemies and the presence of endophytic fungi were manipulated simultaneously. Target colonies of aphids were monitored for 8 weeks starting from their natural appearance in the field to the end of the aphid season. 3. We show that on Lolium perenne increased natural enemy densities reduced the individual numbers of two common cereal aphids, Rhopalosiphum padi and Metopolophium festucae. 4. The presence of the endophytic fungi Neotyphodium lolii reduced the number of M. festucae but did not affect the number of R. padi. The reduction in R. padi numbers by predators and parasitoids was not influenced by the presence of endophytes. For adult M. festucae, however, the negative effects of natural enemies were significant only in the absence of endophytes. 5. Over the duration of the experiment, the effect of natural enemies on aphid colony growth was much stronger than the effect of the endophytic fungi N. lolii, presumably because predator and parasitoid action on aphid colonies is much faster than any effects of endophytes. 6. Our results demonstrate that with simultaneous action of acquired endosymbionts and natural enemies, both factors can control aphid colony growth but they generally act independently of each other.

  14. Macrosiphoniella remaudierei, a new species of aphid on Helichrysum in Iran (Hemiptera, Aphididae)

    Science.gov (United States)

    Barbagallo, Sebastiano; Nieto Nafría, Juan M.

    2016-01-01

    Abstract A new species of aphid, belonging to the genus Macrosiphoniella Del Guercio, 1911, is described using three samples collected in Iran on Helichrysum armenium (Asteraceae, Inuleae) by the late Prof. G. Remaudière. Both apterous and alate viviparous females of the new taxon, Macrosiphoniella remaudierei sp. n., are described and compared to corresponding morphs of the closely allied Macrosiphoniella aetnensis and to other congeneric aphid species on Helichrysum in the Palaearctic region. Type specimens are now stored in the Muséum national d’Histoire naturelle in Paris. PMID:28138287

  15. Macrosiphoniella remaudierei, a new species of aphid on Helichrysum in Iran (Hemiptera, Aphididae

    Directory of Open Access Journals (Sweden)

    Sebastiano Barbagallo

    2017-01-01

    Full Text Available A new species of aphid, belonging to the genus Macrosiphoniella Del Guercio, 1911, is described using three samples collected in Iran on Helichrysum armenium (Asteraceae, Inuleae by the late Prof. G. Remaudière. Both apterous and alate viviparous females of the new taxon, M. remaudierei sp. n., are described and compared to corresponding morphs of the closely allied M. aetnensis and to other congeneric aphid species on Helichrysum in the Palaearctic region. Type specimens are now stored in the Muséum national d’Histoire naturelle in Paris.

  16. New invasive species of aphids (Hemiptera, Aphididae in Serbia and Montenegro

    Directory of Open Access Journals (Sweden)

    Petrović-Obradović Olivera

    2010-01-01

    Full Text Available Three new invasive species of aphids have been found in Serbia: Chaitophorus populifolli Essig, Myzocallis walshii (Monell and Trichosiphonaphis polygonifoliae (Shinji and two have been found in Montenegro: Aphis illinoisensis Shimer and Tinocallis kahawaluokalani (Kirkaldy. A. illinoisensis is a pest of the grapevine, T. polygonifoliae, feeds on a decorative shrub (Lonicera and the other three feed on trees (Populus, Quercus and Lagerostroemia. Three of the species are American aphids and two are of Asian origin. Their morphology, illustrated by original drawings and data on the biology and distribution are given. .

  17. Comparative analysis of Solanum stoloniferum responses to probing by the green peach aphid Myzus persicae and the potato aphid Macrosiphum euphorbiae

    Institute of Scientific and Technical Information of China (English)

    Adriana E.Alvarez; Viviana G.Broglia; Anahí M.Alberti D'Amato; Doret Wouters; Edwin van der Vossen; Elisa Garzo; W.Fred Tjallingii

    2013-01-01

    Plants protect themselves against aphid attacks by species-specific defense mechanisms.Previously,we have shown that Solanum stoloniferum Schlechtd has resistance factors to Myzus persicae Sulzer (Homoptera:Aphididae) at the epidermal/mesophyll level that are not effective against Macrosiphum euphorbiae Thomas (Homoptera:Aphididae).Here,we compare the nymphal mortality,the pre-reproductive development time,and the probing behavior of M.persicae and M.euphorbiae on S.stoloniferum and Solanum tuberosum L.Furthermore,we analyze the changes in gene expression in S.stoloniferum 96 hours post infestation by either aphid species.Although the M.euphorbiae probing behavior shows that aphids encounter more probing constrains on phloem activities-longer probing and salivation time-on S.stoloniferum than on S.tuberosum,the aphids succeeded in reaching a sustained ingestion of phloem sap on both plants.Probing by M.persicae on S.stoloniferum plants resulted in limited feeding only.Survival of M.euphorbiae and M.persicae was affected on young leaves,but not on senescent leaves of S.stoloniferum.Infestation by M.euphorbiae changed the expression of more genes than M.persicae did.At the systemic level both aphids elicited a weak response.Infestation of S.stoloniferum plants with a large number ofM.persicae induced morphological changes in the leaves,leading to the development of pustules that were caused by disrupted vascular parenchyma and surrounding tissue.In contrast,an infestation by M.euphorbiae had no morphological effects.Both plant species can be regarded as good host for M.euphorbiae,whereas only S.tuberosum is a good host for Mo persicae and S.stoloniferum is not.Infestation of S.stoloniferum by M.persicae or M.euphorbiae changed the expression of a set of plant genes specific for each of the aphids as well as a set of common genes.

  18. Bacterial symbionts, Buchnera, and starvation on wing dimorphism in English grain aphid, Sitobion avenae (F. (Homoptera: Aphididae

    Directory of Open Access Journals (Sweden)

    Fangmei eZhang

    2015-05-01

    Full Text Available Wing dimorphism in aphids can be affected by multiple cues, including both biotic (nutrition, crowding, interspecific interactions, the presence of natural enemies, maternal and transgenerational effects, and alarm pheromone and abiotic factors (temperature, humidity, and photoperiod. The majority of the phloem-feeding aphids carry Buchnera, an obligate symbiotic proteobacteria. Buchnera has a highly reduced genome size, but encode key enzymes in the tryptophan biosynthetic pathway and is crucial for nutritional balance, development and reproduction in aphids. In this study, we investigated the impact of two nutritional-based biotic factors, symbionts and starvation, on the wing dimorphism in the English grain aphid, Sitobion avenae, a devastating insect pest of cereal crops (e.g., wheat worldwide. Elimination of Buchnera using the antibiotic rifampicin significantly reduced the formation of winged morphs, body mass and fecundity in S. avenae. Furthermore, the absence of this primary endosymbiont may disrupt the nutrient acquisition in aphids and alter transgenerational phenotypic expression. Similarly, both survival rate and the formation of winged morphs were substantially reduced after neonatal (< 24h old offspring were starved for a period of time. The combined results shed light on the impact of two nutritional-based biotic factors on the phenotypic plasticity in aphids. A better understanding of the wing dimorphism in aphids will provide the theoretical basis for the prediction and integrated management of these phloem-feeding insect pests.

  19. Use of slow-release plant infochemicals to control aphids: a first investigation in a Belgian wheat field

    Science.gov (United States)

    Zhou, Haibo; Chen, Longsheng; Liu, Yong; Chen, Julian; Francis, Frédéric

    2016-01-01

    Using infochemicals to develop a push–pull strategy in pest control is a potential way to promote sustainable crop production. Infochemicals from plant essential oils were mixed with paraffin oil for slow release in field experiments on wheat to control the population density of cereal aphids and to enhance their natural enemies. (Z)-3-Hexenol (Z3H) attracted Metopolophum dirhodum and Sitobion avenae, the predominant species on wheat in Belgium, and may be a useful infochemical for aphid control by attracting aphids away from field plots. Release of (E)-β-farnesene (EBF) or a garlic extract (GE) led to a significant decrease in the abundance of wheat aphids. The main natural enemies of cereal aphids found were lacewings (47.8%), hoverflies (39.4%), and ladybirds (12.8%). Ladybird abundance varied little before the end of the wheat-growing season. Our results suggest that these chemicals can form the basis of a “push–pull” strategy for aphid biological control, with GE and EBF acting as a pest- and beneficial-pulling stimulus and Z3H for aphid pulling. PMID:27530318

  20. Use of slow-release plant infochemicals to control aphids: a first investigation in a Belgian wheat field.

    Science.gov (United States)

    Zhou, Haibo; Chen, Longsheng; Liu, Yong; Chen, Julian; Francis, Frédéric

    2016-08-17

    Using infochemicals to develop a push-pull strategy in pest control is a potential way to promote sustainable crop production. Infochemicals from plant essential oils were mixed with paraffin oil for slow release in field experiments on wheat to control the population density of cereal aphids and to enhance their natural enemies. (Z)-3-Hexenol (Z3H) attracted Metopolophum dirhodum and Sitobion avenae, the predominant species on wheat in Belgium, and may be a useful infochemical for aphid control by attracting aphids away from field plots. Release of (E)-β-farnesene (EBF) or a garlic extract (GE) led to a significant decrease in the abundance of wheat aphids. The main natural enemies of cereal aphids found were lacewings (47.8%), hoverflies (39.4%), and ladybirds (12.8%). Ladybird abundance varied little before the end of the wheat-growing season. Our results suggest that these chemicals can form the basis of a "push-pull" strategy for aphid biological control, with GE and EBF acting as a pest- and beneficial-pulling stimulus and Z3H for aphid pulling.

  1. Density-dependent interference of aphids with caterpillar-induced defenses in Arabidopsis: involvement of phytohormones and transcription factors.

    Science.gov (United States)

    Kroes, Anneke; van Loon, Joop J A; Dicke, Marcel

    2015-01-01

    In nature, plants are exposed to attacks by multiple herbivore species at the same time. To cope with these attacks, plants regulate defenses with the production of hormones such as salicylic acid (SA) and jasmonic acid (JA). Because herbivore densities are dynamic in time, this may affect plant-mediated interactions between different herbivores attacking at the same time. In Arabidopsis thaliana, feeding by Brevicoryne brassicae aphids interferes with induced defenses against Plutella xylostella caterpillars. This is density dependent: at a low aphid density, the growth rate of P. xylostella was increased, whereas caterpillars feeding on plants colonized by aphids at a high density have a reduced growth rate. Growth of P. xylostella larvae was unaffected on sid2-1 or on dde2-2 mutant plants when feeding simultaneously with a low or high aphid density. This shows that aphid interference with caterpillar-induced defenses requires both SA and JA signal transduction pathways. Transcriptional analysis revealed that simultaneous feeding by caterpillars and aphids at a low density induced the expression of the SA transcription factor gene WRKY70 whereas expression of WRKY70 was lower in plants induced with both caterpillars and a high aphid density. Interestingly, the expression of the JA transcription factor gene MYC2 was significantly higher in plants simultaneously attacked by aphids at a high density and caterpillars. These results indicate that a lower expression level of WRKY70 leads to significantly higher MYC2 expression through SA-JA cross-talk. Thus, plant-mediated interactions between aphids and caterpillars are density dependent and involve phytohormonal cross-talk and differential activation of transcription factors.

  2. Aphids preserved in propylene glycol can be used for reverse transcription-polymerase chain reaction detection of Potato virus Y.

    Science.gov (United States)

    Nie, Xianzhou; Pelletier, Yvan; Mason, Nicola; Dilworth, Andrea; Giguère, Marie-Andrée

    2011-08-01

    The effectiveness of propylene glycol on the retention of RNA target of Potato virus Y (PVY), an aphid stylet-borne virus, in Myzus persicae was investigated in comparison to ethanol and liquid nitrogen/-80°C. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the PVY targets from the propylene glycol/ethanol/liquid nitrogen preserved single aphids after a 5min acquisition period from infected potato plants. In the liquid nitrogen/-80°C and 70% ethanol treatments, 55.6% and 38.8% aphids tested PVY-positive, respectively. In the 0-75% propylene glycol treatments, 12.2-44.7% aphids tested PVY-positive. The lowest detection rate was in the 0% (positive rate, 15.2%) and the 10% propylene glycol (positive rate, 12.2%). As the propylene glycol concentration increased to 25%, 29.8% aphids tested positive. A high PVY-positive rate was also found in 35-75% propylene glycol treatments at 44.7% (35% propylene glycol), 36.7% (50% propylene glycol) and 34.8% (75% propylene glycol), which is comparable to the rate shown in 70% ethanol. No significant difference in the positive detection rate was observed in aphids preserved in 50% propylene glycol at room temperature for 2, 4 and 10 days. These results demonstrate that propylene glycol at 25-75% can retain PVY targets effectively in aphids for an extended time period, and thus can be used in aphid traps to preserve viruliferous aphids for later RT-PCR detection of PVY.

  3. Evidence for an invasive aphid "superclone": extremely low genetic diversity in Oleander aphid (Aphis nerii populations in the southern United States.

    Directory of Open Access Journals (Sweden)

    John Scott Harrison

    Full Text Available BACKGROUND: The importance of genetic diversity in successful biological invasions is unclear. In animals, but not necessarily plants, increased genetic diversity is generally associated with successful colonization and establishment of novel habitats. The Oleander aphid, Aphis nerii, though native to the Mediterranean region, is an invasive pest species throughout much of the world. Feeding primarily on Oleander (Nerium oleander and Milkweed (Asclepias spp. under natural conditions, these plants are unlikely to support aphid populations year round in the southern US. The objective of this study was to describe the genetic variation within and among US populations of A. nerii, during extinction/recolonization events, to better understand the population ecology of this invasive species. METHODOLOGY/PRINCIPAL FINDINGS: We used five microsatellite markers to assess genetic diversity over a two year period within and among three aphid populations separated by small (100 km and large (3,700 km geographic distances on two host plant species. Here we provide evidence for A. nerii "superclones". Genotypic variation was absent in all populations (i.e., each population consisted of a single multilocus genotype (MLG or "clone" and the genetic composition of only one population completely changed across years. There was no evidence of sexual reproduction or host races on different plant species. CONCLUSIONS/SIGNIFICANCE: Aphis nerii is a well established invasive species despite having extremely low genetic diversity. As this aphid appears to be obligatorily asexual, it may share more similarities with clonally reproducing invasive plants, than with other animals. Patterns of temporal and geographic genetic variation, viewed in the context of its population dynamics, have important implications for the management of invasive pests and the evolutionary biology of asexual species.

  4. Parasitoids (Hymenoptera: Braconidae: Aphidiinae) of northeastern Iran: aphidiine-aphid-plant associations, key and description of a new species.

    Science.gov (United States)

    Rakhshani, Ehsan; Kazemzadeh, Sedigheh; Starý, Petr; Barahoei, Hossein; Kavallieratos, Nickolas G; Ćetković, Aleksandar; Popović, Anđelka; Bodlah, Lmran; Tomanović, Željko

    2012-01-01

    Aphid parasitoids of the subfamily Aphidiinae (Hymenoptera: Braconidae) of northeastern Iran were studied in this paper. A total of 29 species are keyed and illustrated with line drawings. The aphidiines presented in this work have been reared from 42 aphid host taxa occurring on 49 plant taxa from a total of 33 sampling sites. Sixty-six aphidiine-aphid-plant associations are presented. Trioxys metacarpalis sp. nov. from Chaitaphis tenuicaudata Nevsky (Hemiptera: Aphididae) on Kochia scoparia, is described. The species diversity based on the comparative faunistic analysis is discussed.

  5. Ants farm subterranean aphids mostly in single clone groups - an example of prudent husbandry for carbohydrates and proteins?

    Directory of Open Access Journals (Sweden)

    Ivens Aniek BF

    2012-07-01

    Full Text Available Abstract Background Mutualistic interactions are wide-spread but the mechanisms underlying their evolutionary stability and ecological dynamics remain poorly understood. Cultivation mutualisms in which hosts consume symbionts occur in phylogenetically diverse groups, but often have symbiont monocultures for each host. This is consistent with the prediction that symbionts should avoid coexistence with other strains so that host services continue to benefit relatives, but it is less clear whether hosts should always favor monocultures and what mechanisms they might have to manipulate symbiont diversity. Few mutualisms have been studied in sufficient genetic detail to address these issues, so we decided to characterize symbiont diversity in the complex mutualism between multiple root aphid species and Lasius flavus ants. After showing elsewhere that three of these aphid species have low dispersal and mostly if not exclusively asexual reproduction, we here investigate aphid diversity within and between ant nest mounds. Results The three focal species (Geoica utricularia, Forda marginata and Tetraneura ulmi had considerable clonal diversity at the population level. Yet more than half of the ant mounds contained just a single aphid species, a significantly higher percentage than expected from a random distribution. Over 60% of these single-species mounds had a single aphid clone, and clones tended to persist across subsequent years. Whenever multiple species/clones co-occurred in the same mound, they were spatially separated with more than 95% of the aphid chambers containing individuals of a single clone. Conclusions L. flavus “husbandry” is characterized by low aphid “livestock” diversity per colony, especially at the nest-chamber level, but it lacks the exclusive monocultures known from other cultivation mutualisms. The ants appear to eat most of the early instar aphids, so that adult aphids are unlikely to face limited phloem resources and

  6. Disruption of Ant-Aphid Mutualism in Canopy Enhances the Abundance of Beetles on the Forest Floor

    OpenAIRE

    Shuang Zhang; Yuxin Zhang; Keming Ma

    2012-01-01

    Ant-aphid mutualism is known to play a key role in the structure of the arthropod community in the tree canopy, but its possible ecological effects for the forest floor are unknown. We hypothesized that aphids in the canopy can increase the abundance of ants on the forest floor, thus intensifying the impacts of ants on other arthropods on the forest floor. We tested this hypothesis in a deciduous temperate forest in Beijing, China. We excluded the aphid-tending ants Lasius fuliginosus from th...

  7. Determination of 4-Chloroindole-3-Acetic Acid Methyl Ester in Lathyrus Vicia and Pisum by Gas Chromatography - Mass Spectrometry

    DEFF Research Database (Denmark)

    Engvild, Kjeld Christensen; Egsgaard, Helge; Larsen, Elfinn

    1980-01-01

    4-Chloroindole-3-acetic acid methyl ester was identified unequivocally in Lathyrus latifolius L., Vicia faba L. and Pisum sativum L. by thin layer chromatography, gas chromatography and mass spectrometry. The gas chromatographic system was able to separate underivatized chloroindole-3-acetic acid...... methyl ester isomers. The quantitative determination of 4-chloroindole-3-acetic acid methyl ester in immature seeds of these three species was performed by gas chromatography – mass spectrometry using deuterium labelled 4-chloro-indole-3-acetic acid methyl ester as an internal standard. P. sativum...

  8. THE EFFECT OF INDUSTRIAL WATER ON THE GERMINATION OF SEEDS AND THE DEVELOPMENT OF SEEDLINGS OF PISUM SATIVUM L.

    OpenAIRE

    Liliana Cristina SOARE; Codruţa-Mihaela DOBRESCU; Liana Elena LASCU

    2011-01-01

    The aim of the research was to highlight the influence of industrial water on the germination of seeds and the development of seedlings of Pisum sativum L., so that the impact of these water on the plants may be assessed, in case of accidental spills. The analysis of polluted industrial water indicates the presence of Cr, Fe, Ni, Pb, Cd, Cu, and Zn concentrations higher than CMA, except Cd, which was below the detection limit, and Cu. On leaving the neutralization station, metal concentration...

  9. Effects of plant protease inhibitors, oryzacystatin I and soybean Bowman-Birk inhibitor, on the aphid Macrosiphum euphorbiae (Homoptera, Aphididae) and its parasitoid Aphelinus abdominalis (Hymenoptera, Aphelinidae).

    Science.gov (United States)

    Azzouz, H; Cherqui, A; Campan, E D M; Rahbé, Y; Duport, G; Jouanin, L; Kaiser, L; Giordanengo, P

    2005-01-01

    Transgenic plants expressing protease inhibitors (PIs) have emerged in recent years as an alternative strategy for pest control. Beneficial insects such as parasitoids may therefore be exposed to these entomotoxins either via the host or by direct exposure to the plant itself. With the objective of assessing the effects of PIs towards aphid parasitoids, bioassays using soybean Bowman-Birk inhibitor (SbBBI) or oryzacystatin I (OCI) on artificial diet were performed on Macrosiphum euphorbiae-Aphelinus abdominalis system. OCI significantly reduced nymphal survival of the potato aphid M. euphorbiae and prevented aphids from reproducing. This negative effect was much more pronounced than with other aphid species. On the contrary, SbBBI did not affect nymphal viability but significantly altered adult demographic parameters. Enzymatic inhibition assays showed that digestive proteolytic activity of larvae and adults of Aphelinus abdominalis predominantly relies on serine proteases and especially on chymotrypsin-like activity. Immunoassays suggested that OCI bound to aphid proteins and accumulated in aphid tissues, whereas SbBBI remained unbound in the gut. Bioassays using M. euphorbiae reared on artificial diets supplemented with both OCI and SbBBI showed a fitness impairment of Aphelinus abdominalis that developed on intoxicated aphids. However, only SbBBI was detected in parasitoid larvae, while no PI could be detected in adult parasitoids that emerged from PI-intoxicated aphids. The potential impact of PI-expressing plants on aphid parasitoids and their combined efficiency for aphid control are discussed.

  10. Metabolic Engineering of Plant-derived (E)-β-farnesene Synthase Genes for a Novel Type of Aphid-resistant Genetically Modified Crop Plants

    Institute of Scientific and Technical Information of China (English)

    Xiu-Dao Yu; John Pickett; You-Zhi Ma; Toby Bruce; Johnathan Napier; Huw D.Jones; Lan-Qin Xia

    2012-01-01

    Aphids are major agricultural pests that cause significant yield losses of crop plants each year.Excessive dependence on insecticides for long-term aphid control is undesirable because of the development of insecticide resistance,the potential negative effects on non-target organisms and environmental pollution.Transgenic crops engineered for resistance to aphids via a non-toxic mode of action could be an efficient alternative strategy.(E)-β-Farnesene (EβF) synthases catalyze the formation of EβF,which for many pest aphids is the main component of the alarm pheromone involved in the chemical communication within these species.EβF can also be synthesized by certain plants but is then normally contaminated with inhibitory compounds.Engineering of crop plants capable of synthesizing and emitting EβF could cause repulsion of aphids and also the attraction of natural enemies that use EβF as a foraging cue,thus minimizing aphid infestation.In this review,the effects of aphids on host plants,plants' defenses against aphid herbivory and the recruitment of natural enemies for aphid control in an agricultural setting are briefly introduced.Furthermore,the plant-derived EβF synthase genes cloned to date along with their potential roles in generating novel aphid resistance via genetically modified approaches are discussed.

  11. Energy budgets of the Chinese green lacewing (Neuroptera: Chrysopidae) and its potential for biological control of the cotton aphid (Homoptera: Aphididae)

    Institute of Scientific and Technical Information of China (English)

    FENG GAO; XIANG-HUI LIU; FENG GE

    2007-01-01

    Energy budgets of larval stages of the Chinese green lacewing, Chrysopa sinica (Tjeder) (Neuroptera: Chrysopidae) were determined under laboratory conditions at photoperiod of 14:10 L:D, 27±1℃ and 75%±2% RH. The energy used as ingestion,assimilation, respiration, productivity and feces was constructed for each developmental stage. In addition, under these experimental conditions, the potential of C.sinica as a biological control agent was evaluated according to the ingestion by this predator and the energy content of cotton aphid, Aphis gossypii (Glover) (Homoptera: Aphididae). The larval stage of C. sinica was able to consume 1281.4 1-day-old aphids, 1018.7 2-day-old aphids,626.9 3-day-old aphids, 393.5 4-day-old aphids, 312.1 5-day-old aphids or 203.5 9-day-old aphids, respectively. No significant difference was detected between the estimated number of aphids consumed by the lacewings using energetic methods and the actual number of aphids consumed by the lacewings in this experiment. Our results showed that C. sinica is an important natural enemy of the cotton aphid, and energetic methods are very useful to quantify biological control efficacy of natural enemies.

  12. Effects of long-term reduced tillage on weed infestation of pea (Pisum sativum L.

    Directory of Open Access Journals (Sweden)

    Andrzej Woźniak

    2014-09-01

    Full Text Available The study evaluated weed infestation of pea (Pisum sativum L. cultivated under conditions of conventional (CT, reduced (RT and herbicide tillage (HT. It demonstrated the highest weed density per m2 in plots with the herbicide (HT and reduced (RT systems and significantly lower weed infestation in plots cultivated in the conventional system (CT. In addition, more weeds occurred at the third leaf stage (13/14 in BBCH scale than at the pod development stage (73/74 BBCH of pea. The highest biomass was produced by weeds in the herbicide system (HT, a lower one – in the reduced system (RT, and the lowest one – in the conventional system (CT. The air-dry weight of weeds depended also on pea development stage. At the pod development stage (73/74 BBCH, the air-dry weight of weeds was significantly higher than at the third leaf stage (13/14 BBCH. The tillage system was also observed to influence the species composition of weeds. This trait was also affected by the period of weed infestation assessment. At the third leaf stage of pea (13/14 BBCH, there occurred 26 weed species, including 24 annual ones. The most abundant species included: Chenopodium album L., Stellaria media (L. Vill., Capsella bursa-pastoris (L. Med., Matricaria inodora L., Thlaspi arvense L., and Fallopia convolvulus (L. A. Löve. At the pod development stage (73/74 BBCH, the pea crop was colonized by 24 weed species, including 3 perennial ones. At this stage the predominant species included: Avena fatua L., Amaranthus retroflexus L., Papaver rhoeas L., Echinochloa crus-galli (L. P.B., Matricaria inodora L., and Galeopsis tetrahit L.

  13. Bean pod mottle virus: a new powerful tool for functional genomics studies in Pisum sativum.

    Science.gov (United States)

    Meziadi, Chouaib; Blanchet, Sophie; Richard, Manon M S; Pilet-Nayel, Marie-Laure; Geffroy, Valérie; Pflieger, Stéphanie

    2016-08-01

    Pea (Pisum sativum L.) is an important legume worldwide. The importance of pea in arable rotations and nutritional value for both human and animal consumption have fostered sustained production and different studies to improve agronomic traits of interest. Moreover, complete sequencing of the pea genome is currently underway and will lead to the identification of a large number of genes potentially associated with important agronomic traits. Because stable genetic transformation is laborious for pea, virus-induced gene silencing (VIGS) appears as a powerful alternative technology for determining the function of unknown genes. In this work, we present a rapid and efficient viral inoculation method using DNA infectious plasmids of Bean pod mottle virus (BPMV)-derived VIGS vector. Six pea genotypes with important genes controlling biotic and/or abiotic stresses were found susceptible to BPMV carrying a GFP reporter gene and showed fluorescence in both shoots and roots. In a second step, we investigated 37 additional pea genotypes and found that 30 were susceptible to BPMV and only 7 were resistant. The capacity of BPMV to induce silencing of endogenes was investigated in the most susceptible genotype using two visual reporter genes: PsPDS and PsKORRIGAN1 (PsKOR1) encoding PHYTOENE DESATURASE and a 1,4-β-D-glucanase, respectively. The features of the 'one-step' BPMV-derived VIGS vector include (i) the ease of rub-inoculation, without any need for biolistic or agro-inoculation procedures, (ii) simple cost-effective procedure and (iii) noninterference of viral symptoms with silencing. These features make BPMV the most adapted VIGS vector in pea to make low- to high-throughput VIGS studies.

  14. Growth, seed development and genetic analysis in wild type and Def mutant of Pisum sativum L

    Directory of Open Access Journals (Sweden)

    Ayeh Kwadwo

    2011-11-01

    Full Text Available Abstract Background The def mutant pea (Pisum sativum L showed non-abscission of seeds from the funicule. Here we present data on seed development and growth pattern and their relationship in predicting this particular trait in wild type and mutant lines as well as the inheritance pattern of the def allele in F2 and F3 populations. Findings Pod length and seed fresh weight increase with fruit maturity and this may affect the abscission event in pea seeds. However, the seed position in either the distal and proximal ends of the pod did not show any difference. The growth factors of seed fresh weight (FW, width of funicles (WFN, seed width (SW and seed height (SH were highly correlated and their relationships were determined in both wild type and def mutant peas. The coefficient of determination R2 values for the relationship between WFN and FW, SW and SH and their various interactions were higher for the def dwarf type. Stepwise multiple regression analysis showed that variation of WFN was associated with SH and SW. Pearson's chi square analysis revealed that the inheritance and segregation of the Def locus in 3:1 ratio was significant in two F2 populations. Structural analysis of the F3 population was used to confirm the inheritance status of the Def locus in F2 heterozygote plants. Conclusions This study investigated the inheritance of the presence or absence of the Def allele, controlling the presence of an abscission zone (AZ or an abscission-less zone (ALZ forming in wild type and mutant lines respectively. The single major gene (Def controlling this phenotype was monogenic and def mutants were characterized and controlled by the homozygous recessive def allele that showed no palisade layers in the hilum region of the seed coat.

  15. Long-Term Fungal Inhibition by Pisum sativum Flour Hydrolysate during Storage of Wheat Flour Bread

    Science.gov (United States)

    Lavecchia, Anna; Gramaglia, Valerio; Gobbetti, Marco

    2015-01-01

    In order to identify antifungal compounds from natural sources to be used as ingredients in the bakery industry, water/salt-soluble extracts (WSE) from different legume flour hydrolysates obtained by the use of a fungal protease were assayed against Penicillium roqueforti DPPMAF1. The agar diffusion assays allowed the selection of the pea (Pisum sativum) hydrolysate as the most active. As shown by the hyphal radial growth rate, the WSE had inhibitory activity towards several fungi isolated from bakeries. The MIC of the WSE was 9.0 mg/ml. Fungal inhibition was slightly affected by heating and variations in pH. The antifungal activity was attributed to three native proteins (pea defensins 1 and 2 and a nonspecific lipid transfer protein [nsLTP]) and a mixture of peptides released during hydrolysis. The three proteins have been reported previously as components of the defense system of the plant. Five peptides were purified from WSE and were identified as sequences encrypted in leginsulin A, vicilin, provicilin, and the nsLTP. To confirm antifungal activity, the peptides were chemically synthesized and tested. Freeze-dried WSE were used as ingredients in leavened baked goods. In particular, breads made by the addition of 1.6% (wt/wt) of the extract and fermented by baker's yeast or sourdough were characterized for their main chemical, structural, and sensory features, packed in polyethylene bags, stored at room temperature, and compared to controls prepared without pea hydrolysate. Artificially inoculated slices of a bread containing the WSE did not show contamination by fungi until at least 21 days of storage and behaved like the bread prepared with calcium propionate (0.3%, wt/wt). PMID:25862230

  16. Preservative potential of cumin essential oil for Pisum sativum L. during storage

    Directory of Open Access Journals (Sweden)

    Kumar Narendra

    2016-04-01

    Full Text Available The samples of stored seeds of pea (Pisum sativum L. were collected from 30 farmer markets. The mycobiota analysis showed presence of 15 fungal species and one species of insect Callosobruchus chinensis. The fungi such as Aspergillus flavus, A. niger, A. ochraceous, A. terreus were found to be dominant based on percent frequency of each in blotter method in unsterilized and sterilized seeds 18.9-7.9, 15.0-3.9, 12.2-3.7, 10.1-1.7, respectively, and in agar plate technique 17.9-8.3, 15.1-9.5, 12.8-5, 7.9.7-6.7, respectively. These species showed reduction in terms of weight loss, germination and protein content in pathogenicity testing. Essential oil extracted by hydrodistillation from fruits of Cuminum cyminum L. was evaluated against the most common occurring funi such as A. flavus and A. niger as well as the insect species C. chinensis and the oil exhibited high toxicity. The oil killed the tested fungi and showed thermostable nature at its minimum inhibitory concentration (MIC of 400 ppm. The oil safely preserved pea seeds up to 120 days at 0.50 (1,000 ppm and 0.76 ml (1,500 ppm in polyethylene and jute bags of 500 ml capacity containing 400 g seeds separately. There were no changes in organoleptic appereance of food seeds during storage. The oil has beneficial effect on number of visible nodule formation and shoot and root dry biomass of 15-day-old plants in comparison to control sets. The cumin oil was analyzed by gas chromatography (GC and gas chromatography-mass spectrometry (GC-MS.

  17. Sitona lineatus (Coleoptera: Curculionidae) Larval Feeding on Pisum sativum L. Affects Soil and Plant Nitrogen.

    Science.gov (United States)

    Cárcamo, Héctor A; Herle, Carolyn E; Lupwayi, Newton Z

    2015-01-01

    Adults of Sitona lineatus (pea leaf weevil, PLW) feed on foliage of several Fabaceae species but larvae prefer to feed on nodules of Pisum sativum L. and Vicia faba L. Indirectly, through their feeding on rhizobia, weevils can reduce soil and plant available nitrogen (N). However, initial soil N can reduce nodulation and damage by the weevil and reduce control requirements. Understanding these interactions is necessary to make integrated pest management recommendations for PLW. We conducted a greenhouse study to quantify nodulation, soil and plant N content, and nodule damage by weevil larvae in relation to soil N amendment with urea, thiamethoxam insecticide seed coating and crop stage. PLWs reduced the number of older tumescent (multilobed) nodules and thiamethoxam addition increased them regardless of other factors. Nitrogen amendment significantly increased soil available N (>99% nitrate) as expected and PLW presence was associated with significantly lower levels of soil N. PLW decreased plant N content at early flower and thiamethoxam increased it, particularly at late flower. The study illustrated the complexity of interactions that determine insect herbivory effects on plant and soil nutrition for invertebrates that feed on N-fixing root nodules. We conclude that effects of PLW on nodulation and subsequent effects on plant nitrogen are more pronounced during the early growth stages of the plant. This suggests the importance of timing of PLW infestation and may explain the lack of yield depression in relation to this pest observed in many field studies. Also, pea crops in soils with high levels of soil N are unlikely to be affected by this herbivore and should not require insecticide inputs.

  18. The tropic response of plant roots to oxygen: oxytropism in Pisum sativum L

    Science.gov (United States)

    Porterfield, D. M.; Musgrave, M. E.

    1998-01-01

    Plant roots are known to orient growth through the soil by gravitropism, hydrotropism, and thigmotropism. Recent observations of plant roots that developed in a microgravity environment in space suggested that plant roots may also orient their growth toward oxygen (oxytropism). Using garden pea (Pisum sativum L. cv. Weibul's Apollo) and an agravitropic mutant (cv. Ageotropum), root oxytropism was studied in the controlled environment of a microrhizotron. A series of channels in the microrhizotron allowed establishment of an oxygen gradient of 0.8 mmol mol-1 mm-1. Curvature of seedling roots was determined prior to freezing the roots for subsequent spectrophotometric determinations of alcohol dehydrogenase activity. Oxytropic curvature was observed all along the gradient in both cultivars of pea. The normal gravitropic cultivar showed a maximal curvature of 45 degrees after 48 h, while the agravitropic mutant curved to 90 degrees. In each cultivar, the amount of curvature declined as the oxygen concentration decreased, and was linearly related to the root elongation rate. Since oxytropic curvature occurred in roots exposed to oxygen concentrations that were not low enough to induce the hypoxically responsive protein alcohol dehydrogenase, we suspect that the oxygen sensor associated with oxytropism does not control the induction of hypoxic metabolism. Our results indicate that oxygen can play a critical role in determining root orientation as well as impacting root metabolic status. Oxytropism allows roots to avoid oxygen-deprived soil strata and may also be the basis of an auto-avoidance mechanism, decreasing the competition between roots for water and nutrients as well as oxygen.

  19. Effect of Rhizobium inoculation of seeds and foliar fertilization on productivity of Pisum sativum L.

    Directory of Open Access Journals (Sweden)

    Tadeusz Zając

    2013-07-01

    Full Text Available Pea (Pisum sativum L. is the second most important grain legume crop in the world which has a wide array of uses for human food and fodder. One of the major factors that determines the use of field pea is the yield potential of cultivars. Presently, pre-sowing inoculation of pea seeds and foliar application of microelement fertilizers are prospective solutions and may be reasonable agrotechnical options. This research was undertaken because of the potentially high productivity of the 'afila' morphotype in good wheat complex soils. The aim of the study was to determine the effect of vaccination with Rhizobium and foliar micronutrient fertilization on yield of the afila pea variety. The research was based on a two-year (2009–2010 controlled field experiment, conducted in four replicates and carried out on the experimental field of the Bayer company located in Modzurów, Silesian region. experimental field soil was Umbrisol – slightly degraded chernozem, formed from loess. Nitragina inoculant, as a source of symbiotic bacteria, was applied before sowing seeds. Green area index (GAI of the canopy, photosynthetically active radiation (PAR, and normalized difference vegetation index (NDVI were determined at characteristic growth stages. The presented results of this study on symbiotic nitrogen fixation by leguminous plants show that the combined application of Nitragina and Photrel was the best combination for productivity. Remote measurements of the pea canopy indexes indicated the formation of the optimum leaf area which effectively used photosynthetically active radiation. The use of Nitragina as a donor of effective Rhizobium for pea plants resulted in slightly higher GAI values and the optimization of PAR and NDVI. It is not recommended to use foliar fertilizers or Nitragina separately due to the slowing of pea productivity.

  20. Inventory and assessment of foliar natural enemies of the soybean aphid (Hemiptera: Aphididae) in South Dakota

    Science.gov (United States)

    Soybean aphid (Aphis glycines Matsumura) (Hemiptera: Aphididae) is a major pest of soybean in northern production regions of North America, and insecticides have been the primary management approach while alternative methods are developed. Knowledge of arthropod natural enemies and their impact on ...

  1. Aphid honeydew quality as a food source for parasitoids is maintained in Bt cotton.

    Science.gov (United States)

    Hagenbucher, Steffen; Wäckers, Felix L; Romeis, Jörg

    2014-01-01

    Bt-transgenic cotton has proven to be highly efficient in controlling key lepidopteran pests. One concern with the deployment of Bt cotton varieties is the potential proliferation of non-target pests. We previously showed that Bt cotton contained lower concentrations of insecticidal terpenoids as a result of reduced caterpillar damage, which benefited the aphid Aphis gossypii. It is thus important that non-target herbivores are under biological control in Bt cotton fields. The induction or lack of induction of terpenoids could also influence the quality of aphid honeydew, an important food source for beneficial insects. We therefore screened A. gossypii honeydew for cotton terpenoids, that are induced by caterpillars but not the aphids. We then tested the influence of induced insect-resistance of cotton on honeydew nutritional quality for the aphid parasitoid Lysiphlebus testaceipes and the whitefly parasitoid Eretmocerus eremicus. We detected the cotton terpenoids gossypol and hemigossypolone in A. gossypii honeydew. Although a feeding assay demonstrated that gossypol reduced the longevity of both parasitoid species in a non-linear, dose-dependent manner, the honeydew was capable of sustaining parasitoid longevity and reproduction. The level of caterpillar damage to Bt and non-Bt cotton had no impact on the quality of honeydew for the parasitoids.These results indicate that the nutritional quality of honeydew is maintained in Bt cotton and is not influenced by induced insect resistance.

  2. Aphid honeydew quality as a food source for parasitoids is maintained in Bt cotton.

    Directory of Open Access Journals (Sweden)

    Steffen Hagenbucher

    Full Text Available Bt-transgenic cotton has proven to be highly efficient in controlling key lepidopteran pests. One concern with the deployment of Bt cotton varieties is the potential proliferation of non-target pests. We previously showed that Bt cotton contained lower concentrations of insecticidal terpenoids as a result of reduced caterpillar damage, which benefited the aphid Aphis gossypii. It is thus important that non-target herbivores are under biological control in Bt cotton fields. The induction or lack of induction of terpenoids could also influence the quality of aphid honeydew, an important food source for beneficial insects. We therefore screened A. gossypii honeydew for cotton terpenoids, that are induced by caterpillars but not the aphids. We then tested the influence of induced insect-resistance of cotton on honeydew nutritional quality for the aphid parasitoid Lysiphlebus testaceipes and the whitefly parasitoid Eretmocerus eremicus. We detected the cotton terpenoids gossypol and hemigossypolone in A. gossypii honeydew. Although a feeding assay demonstrated that gossypol reduced the longevity of both parasitoid species in a non-linear, dose-dependent manner, the honeydew was capable of sustaining parasitoid longevity and reproduction. The level of caterpillar damage to Bt and non-Bt cotton had no impact on the quality of honeydew for the parasitoids.These results indicate that the nutritional quality of honeydew is maintained in Bt cotton and is not influenced by induced insect resistance.

  3. Host plants indirectly influence plant virus transmission by altering gut cysteine protease activity of aphid vectors

    Science.gov (United States)

    Luteoviridae), transmitted exclusively by aphids in a circulative manner. PLRV transmission efficiency was significantly reduced when a clonal lineage of M. persicae was reared on turnip as compared to the weed physalis, a transient effect caused by a host-switch response. A trend of higher PLRV tit...

  4. Preference of the green peach aphid, Myzus persicae, for plants grown in sewage sludges

    Energy Technology Data Exchange (ETDEWEB)

    Culliney, T.W.; Pimentel, D.

    1987-08-01

    Since passage of the Clean Water Act in the 1970s, disposal of the millions of tonnes of sewage sludge generated annually has become a major concern of municipalities throughout the United States. With the range of other disposal options having narrowed in recent years, application of sludge to land is increasingly viewed as a practical and economical means to recycle this waste material. However, sludges from large cities with industries may be contaminated with various toxic chemicals, including polychlorinated biphenyls (PCBs), other organic chemicals, such as pesticides, and heavy metals. Sludge application to land thus has the potential adversely to affect biota and the functioning of terrestrial ecosystems. The authors previously demonstrated marked reductions in fecundity and survival of green peach aphids, Myzus persicae, on collard plants, Brassica oleracea var. sabellica, growing in soil treated with chemically contaminated sludge as compared to aphids on plants growing either in soil treated with uncontaminated sludge of soil conventionally fertilized. Reduced plant growth and increased restlessness in aphids in the contaminated sludge treatment were also observed. The purpose of the present study was to examine more closely the influence of sludge contaminants on aphid settling behavior as indicated by differential preference of M. persicae for leaves of its collard host grown under different soil conditions.

  5. Reproduction and dispersal in an ant-associated root aphid community

    DEFF Research Database (Denmark)

    Ivens, A.B.F.; Kronauer, Daniel Jan Christoph; Pen, I.;

    2012-01-01

    viscosity is high and winged aphids rare, consistent with infrequent horizontal transmission between ant host colonies. The absence of the primary host shrub (Pistacia) may explain the absence of sex in three of the studied species, but elm trees (Ulmus) that are primary hosts of the fourth species (T...

  6. Resistance to Cucurbit aphid-borne yellows virus in Melon Accession TGR-1551.

    Science.gov (United States)

    Kassem, Mona A; Gosalvez, Blanca; Garzo, Elisa; Fereres, Alberto; Gómez-Guillamón, Maria Luisa; Aranda, Miguel A

    2015-10-01

    The genetic control of resistance to Cucurbit aphid-borne yellows virus (CABYV; genus Polerovirus, family Luteoviridae) in the TGR-1551 melon accession was studied through agroinoculation of a genetic family obtained from the cross between this accession and the susceptible Spanish cultivar 'Bola de Oro'. Segregation analyses were consistent with the hypothesis that one dominant gene and at least two more modifier genes confer resistance; one of these additional genes is likely present in the susceptible parent 'Bola de Oro'. Local and systemic accumulation of the virus was analyzed in a time course experiment, showing that TGR-1551 resistance was expressed systemically as a significant reduction of virus accumulation compared with susceptible controls, but not locally in agroinoculated cotyledons. In aphid transmission experiments, CABYV inoculation by aphids was significantly reduced in TGR-1551 plants, although the virus was acquired at a similar rate from TGR-1551 as from susceptible plants. Results of feeding behavior studies using the DC electrical penetration graph technique suggested that viruliferous aphids can salivate and feed from the phloem of TGR-1551 plants and that the observed reduction in virus transmission efficiency is not related to reduced salivation by Aphis gossypii in phloem sieve elements. Since the virus is able to accumulate to normal levels in agroinoculated tissues, our results suggest that resistance of TGR-1551 plants to CABYV is related to impairment of virus movement or translocation after it reaches the phloem sieve elements.

  7. The helper component-proteinase of cowpea aphid-borne mosaic virus

    NARCIS (Netherlands)

    Mlotshwa, S.

    2000-01-01

    Cowpea aphid-borne mosaic potyvirus causes severe yield losses in cowpea, an important legume crop in semi-arid regions of Africa. We have elucidated the genomic sequence of the virus and subsequently focused our attention on the so-called helper component-proteinase (HC-Pro), a virus-encoded multif

  8. Reproduction and Population Dynamics as Biotypic Markers of Russian Wheat Aphid Diuraphis noxia (Kurdjumov).

    Science.gov (United States)

    Ngenya, Watson; Malinga, Joyce; Tabu, Isaiah; Masinde, Emily

    2016-04-02

    Russian wheat aphid Diuraphis noxia (Kurdjumov) is widely established in wheat-growing countries where it causes significant economic losses. The development and use of Russian wheat aphid (RWA)-resistant wheat varieties has been constrained by the variation in resident RWA populations and the evolution of virulent biotypes. An experiment was set up at the Kenya Agricultural and Livestock Research Organization (KALRO), Njoro, to characterize RWA populations based on phenotypic characteristics of reproduction, development and population dynamics. RWA populations from the regions of Eldoret, Mau Narok and Njoro were used in the study. A factorial experiment was set up in randomized complete block design replicated eleven times. A single day-old nymph was placed on a new, fully-open leaf in a 0.5 cm-diameter clear plastic straw leaf cage and observed daily for its entire lifetime. The results showed that there were variations in aphid lifespan, reproductive longevity and aphid fecundity between populations, indicating that the phenotypic markers used to determine biotypes were good enough to show distinct biotypes among populations of the RWA in Kenya. Further, the study concluded that the use of phenotypic life and reproductive markers was a valid way of characterizing biotypes of RWA worldwide.

  9. Which shrubs and trees can conserve natural enemies of aphids in spring?

    NARCIS (Netherlands)

    P.C.J. van Rijn

    2014-01-01

    Habitats with shrubs and trees within the agricultural landscape may contribute to the maintenance of natural enemies of pests. Aphids and flowers are important resources for beneficial natural enemies such as ladybeetles, hoverflies and lacewings. Woody plants are the most likely candidates to prov

  10. Changes in large-scale climate alter spatial synchrony of aphid pests

    Science.gov (United States)

    Sheppard, Lawrence W.; Bell, James R.; Harrington, Richard; Reuman, Daniel C.

    2016-06-01

    Spatial synchrony, the tendency of distant populations to fluctuate similarly, is a major concern in ecology. Except in special circumstances, researchers historically had difficulty identifying drivers of synchrony in field systems. Perhaps for this reason, the possibility that changes in large-scale climatic drivers may modify synchrony, thereby impacting ecosystems and human concerns, has been little examined. Here, we use wavelets to determine environmental drivers of phenological synchrony across Britain for 20 aphid species, most major crop pests. Consistently across species, changes in drivers produced large changes in aphid synchrony. Different drivers acted on different timescales: using a new wavelet analogue of the Moran theorem, we show that on long timescales (>4 years), 80% of synchrony in aphid first flights is due to synchrony in winter climate; but this explanation accounts for less short-timescale (Changes in aphid synchrony over time also differed by timescale: long-timescale synchrony fell from before 1993 to after, caused by similar changes in winter climate; whereas short-timescale synchrony increased. Shifts in winter climate are attributable to the North Atlantic Oscillation, an important climatic phenomenon, so effects described here may influence other taxa. This study documents a new way that climatic changes influence populations, through altered Moran effects.

  11. Managing papaya ringspot virus: Impact of grass barriers on alate aphid immigration into papaya orchards

    Science.gov (United States)

    Papaya ringspot virus, transmitted by alate aphids, is the most limiting factor of papaya production in the Caribbean region. Although there are transgenic papaya varieties that provide protection from this virus, these varieties are effective only in certain regions against certain strains of the v...

  12. Effects of insecticides on strawberry aphid Chaetosiphon fragaefolii (Cockerell) on resistant and susceptible strawberry genotypes

    OpenAIRE

    2011-01-01

    Strawberry aphid, Chaetosiphon fragaefolii (Cockerell), is the most important vector of strawberry virus. Breeding of genotypes resistant to this pest is an important preventive control measure, which can be compatible with rational insecticide application. The aim of the paper was to determine effects of dimethoate and deltamethrin on C. fragaefolii populations reared on two strawberry genotypes different in susceptibility: susceptible strawberry cultivar ...

  13. Characterization and genetic dissection of resistance to spotted alfalfa aphid (Therioaphis trifolii) in Medicago truncatula

    KAUST Repository

    Kamphuis, L. G.

    2013-09-21

    Aphids cause significant yield losses in agricultural crops worldwide. Medicago truncatula, a model legume, cultivated pasture species in Australia and close relative of alfalfa (Medicago sativa), was used to study the defence response against Therioaphis trifolii f. maculate [spotted alfalfa aphid (SAA)]. Aphid performance and plant damage were compared among three accessions. A20 is highly susceptible, A17 has moderate resistance, and Jester is strongly resistant. Subsequent analyses using A17 and A20, reciprocal F1s and an A17×A20 recombinant inbred line (RIL) population revealed that this moderate resistance is phloem mediated and involves antibiosis and tolerance but not antixenosis. Electrical penetration graph analysis also identified a novel waveform termed extended potential drop, which occurred following SAA infestation of M. truncatula. Genetic dissection using the RIL population revealed three quantitative trait loci on chromosomes 3, 6, and 7 involved in distinct modes of aphid defence including antibiosis and tolerance. An antibiosis locus resides on linkage group 3 (LG3) and is derived from A17, whereas a plant tolerance and antibiosis locus resides on LG6 and is derived from A20, which exhibits strong temporary tolerance. The loci identified reside in regions harbouring classical resistance genes, and introgression of these loci in current medic cultivars may help provide durable resistance to SAA, while elucidation of their molecular mechanisms may provide valuable insight into other aphid–plant interactions.

  14. Evaluation and reselection of wheat resistance to Russian wheat aphid biotype 2

    Science.gov (United States)

    Russian wheat aphid (RWA, Diuraphis noxia, Mordvilko) biotype 2 (RWA2) is virulent to most known RWA resistance genes and severely threatens wheat production in the hard winter wheat area of the US western Great Plains. We determined RWA2 reactions of 386 cultivars from China, 227 advanced breeding...

  15. Local and systemic responses induced by aphids in Solanum tuberosum plants

    NARCIS (Netherlands)

    Dugravot, S.; Brunissen, L.; Létocart, E.; Tjallingii, W.F.; Vincent, C.; Giordanengo, Ph.; Cherqui, A.

    2007-01-01

    The aphids Macrosiphum euphorbiae (Thomas) and Myzus persicae (Sulzer) (Homoptera: Aphididae) are serious pests of potato (Solanum tuberosum L.) (Solanaceae), notably in transmitting several plant viruses. Heterospecific interactions may occur between these two species as they are often seen at the

  16. Probing behavior of apterous and alate morphs of two potato-colonizing aphids.

    Science.gov (United States)

    Boquel, Sébastien; Giordanengo, Philippe; Ameline, Arnaud

    2011-01-01

    Secondary host plant colonization by aphids involves alate and apterous morphs to spread in the population at a large scale by flying or, at a finer one, by walking. Macrosiphum euphorbiae Thomas (Hemiptera: Aphididae) and Myzus persicae Sulzer (Hemiptera: Aphididae) are two polyphagous aphids that cause serious losses on many crops, particularly on potato, Solanum tuberosum L. (Solanales: Solanaceae). When settlement of virginoparous alate aphids occurs, apterous individuals are produced and spread within the potato field. As these two potato colonizers originate from different areas and show different body length, this study compared probing behaviors of virginoparous alate and apterous M. persicae and M. euphorbiae on one of their secondary host plants, Solanum tuberosum. Non–choice bioassays and electrical penetration graph (EPG) recordings were performed. Most M. euphorbiae of the two morphs rapidly accepted potato plants and exhibited long duration of probing, phloem sap salivation, and ingestion phases. In contrast, at the end of the experiment, most alates of M. persicae left the potato leaflet after brief gustative probes. Moreover, EPG experiments showed that the main difference between both morphs of the two species concerned the xylem ingestion parameter. Differences between species were also reported, such as an increased total duration of probing in both morphs and enhanced phloem ingestion duration in apterous M. euphorbiae. All the differences highlighted in this study are discussed according to the variations observed in aphid body size and to their historical association with Solanum species.

  17. Probing Behavior of Apterous and Alate Morphs of two Potato—Colonizing Aphids

    Science.gov (United States)

    Boquel, Sébastien; Giordanengo, Philippe; Ameline, Arnaud

    2011-01-01

    Secondary host plant colonization by aphids involves alate and apterous morphs to spread in the population at a large scale by flying or, at a finer one, by walking. Macrosiphum euphorbiae Thomas (Hemiptera: Aphididae) and Myzus persicae Sulzer (Hemiptera: Aphididae) are two polyphagous aphids that cause serious losses on many crops, particularly on potato, Solanum tuberosum L. (Solanales: Solanaceae). When settlement of virginoparous alate aphids occurs, apterous individuals are produced and spread within the potato field. As these two potato colonizers originate from different areas and show different body length, this study compared probing behaviors of virginoparous alate and apterous M. persicae and M. euphorbiae on one of their secondary host plants, Solanum tuberosum. Non—choice bioassays and electrical penetration graph (EPG) recordings were performed. Most M. euphorbiae of the two morphs rapidly accepted potato plants and exhibited long duration of probing, phloem sap salivation, and ingestion phases. In contrast, at the end of the experiment, most alates of M. persicae left the potato leaflet after brief gustative probes. Moreover, EPG experiments showed that the main difference between both morphs of the two species concerned the xylem ingestion parameter. Differences between species were also reported, such as an increased total duration of probing in both morphs and enhanced phloem ingestion duration in apterous M. euphorbiae. All the differences highlighted in this study are discussed according to the variations observed in aphid body size and to their historical association with Solanum species. PMID:22242548

  18. Agronomic aspects of strip intercropping lettuce with alyssum for biological control of aphids

    Science.gov (United States)

    Organic growers in California typically devote 5 to 10% of the area in lettuce (Lactuca sativa L.) fields to insectary strips of alyssum (Lobularia maritime (L.) Desv.) to attract syrphid flies (Syrphidae) whose larvae provide biological control of aphids. A 2-year study with organic romaine lettuc...

  19. Subcellular location of the helper component-proteinase of Cowpea Aphid-Borne Mosaic Virus

    NARCIS (Netherlands)

    Mlotshwa, S.; Verver, J.; Sithole-Niang, I.; Gopinath, K.; Carette, J.; Kammen, van A.; Wellink, J.

    2002-01-01

    The helper component-proteinase (HC-Pro) of Cowpea aphid-borne mosaic virus (CABMV) was expressed in Escherichia coli and used to obtain HC-Pro antiserum that was used as an analytical tool for HC-Pro studies. The antiserum was used in immunofluorescence assays to study the subcellular location of H

  20. Facultative endosymbionts of aphid populations from coastal dunes of the North Sea

    NARCIS (Netherlands)

    Pena, de la E.; Vandomme, V.; Frago Clols, E.

    2014-01-01

    Aphids establish symbiotic associations with a diverse assemblage of mutualistic bacteria. Some of them are not required for the host’s survival but still have a crucial impact on the biology and ecology of their host. Facultative symbionts may modify important host-life-history traits and affect th

  1. Foraging by Hippodamia convergens for the aphid Sitobion avenae on wheat plants growing in greenhouse plots

    Science.gov (United States)

    We investigated predation by adult convergent lady beetle, Hippodamia convergens Guerin-Meneville, on English grain aphid, Sitobion avenae L., on wheat, Triticum aestivum L., growing in 1.8 x 1.8 m plantings in a greenhouse with a soil floor. The wheat was planted to simulate wheat in a typical pro...

  2. Prey foraging movements by Hippodamia convergens in wheat are influenced by hunger and aphids

    Science.gov (United States)

    We investigated foraging movements by adult female convergent lady beetles, Hippodamia convergens Guerin-Meneville, on English grain aphids, Sitobion avenae L., on wheat, Triticum aestivum L., growing in 1.8 x 1.8 m plantings in a greenhouse with a soil floor. The wheat was planted to simulate whea...

  3. Why the aphid Aphis spiraecola is more abundant on clementine tree than Aphis gossypii?

    Science.gov (United States)

    Mostefaoui, Houda; Allal-Benfekih, Leila; Djazouli, Zahr-Eddine; Petit, Daniel; Saladin, Gaëlle

    2014-02-01

    Aphis spiraecola and Aphis gossypii cause harmful damages on clementine tree orchards. Weekly surveys measured the abundance of aphids (larvae, winged and wingless adults) as well as of auxiliary insects and parameters of energy metabolism. Correlatively, soluble carbohydrates, total free amino acids, free proline and condensed tannins were quantified in control and infested leaves. Both aphid species showed parallel temporal variations, but A. spiraecola was consistently more abundant regardless of the stage. Amino acids had a positive effect on both aphid species abundance, but neither condensed tannins nor auxiliary insects seemed to modulate aphid populations. Interestingly, the leaf carbohydrate content was positively correlated with the abundance of A. spiraecola, but not with that of A. gossypii. Moreover, A. gossypii's abundance was significantly down-regulated by high proline concentrations. Thus, the higher abundance of A. spiraecola could be explained by a better tolerance to high proline contents and a better conversion of foliar energy metabolites.

  4. Contribution of fungal loline alkaloids to protection from aphids in a grass-endophyte mutualism.

    Science.gov (United States)

    Wilkinson, H H; Siegel, M R; Blankenship, J D; Mallory, A C; Bush, L P; Schardl, C L

    2000-10-01

    Fungal endophytes provide grasses with enhanced protection from herbivory, drought, and pathogens. The loline alkaloids (saturated 1-aminopyrrolizidines with an oxygen bridge) are fungal metabolites often present in grasses with fungal endophytes of the genera Epichloë or Neotyphodium. We conducted a Mendelian genetic analysis to test for activity of lolines produced in plants against aphids feeding on those plants. Though most loline-producing endophytes are asexual, we found that a recently described sexual endophyte, Epichloë festucae, had heritable variation for loline alkaloid expression (Lol+) or nonexpression (Lol-). By analyzing segregation of these phenotypes and of linked DNA polymorphisms in crosses, we identified a single genetic locus controlling loline alkaloid expression in those E. festucae parents. We then tested segregating Lol+ and Lol- full-sibling fungal progeny for their ability to protect host plants from two aphid species, and observed that alkaloid expression cosegregated with activity against these insects. The in planta loline alkaloid levels correlated with levels of anti-aphid activity. These results suggested a key role of the loline alkaloids in protection of host plants from certain aphids, and represent, to our knowledge, the first Mendelian analysis demonstrating how a fungal factor contributes protection to plant-fungus mutualism.

  5. Reproduction and Population Dynamics as Biotypic Markers of Russian Wheat Aphid Diuraphis noxia (Kurdjumov

    Directory of Open Access Journals (Sweden)

    Watson Ngenya

    2016-04-01

    Full Text Available Russian wheat aphid Diuraphis noxia (Kurdjumov is widely established in wheat-growing countries where it causes significant economic losses. The development and use of Russian wheat aphid (RWA-resistant wheat varieties has been constrained by the variation in resident RWA populations and the evolution of virulent biotypes. An experiment was set up at the Kenya Agricultural and Livestock Research Organization (KALRO, Njoro, to characterize RWA populations based on phenotypic characteristics of reproduction, development and population dynamics. RWA populations from the regions of Eldoret, Mau Narok and Njoro were used in the study. A factorial experiment was set up in randomized complete block design replicated eleven times. A single day-old nymph was placed on a new, fully-open leaf in a 0.5 cm-diameter clear plastic straw leaf cage and observed daily for its entire lifetime. The results showed that there were variations in aphid lifespan, reproductive longevity and aphid fecundity between populations, indicating that the phenotypic markers used to determine biotypes were good enough to show distinct biotypes among populations of the RWA in Kenya. Further, the study concluded that the use of phenotypic life and reproductive markers was a valid way of characterizing biotypes of RWA worldwide.

  6. Evaluation of mirid predatory bugs and release strategy for aphid control in sweet pepper

    NARCIS (Netherlands)

    Messelink, G.J.; Bloemhard, C.M.J.; Hoogerbrugge, H.; Schelt, van J.; Ingegno, B.L.; Tavella, L.

    2015-01-01

    Zoophytophagous predators of the family Miridae (Heteroptera), which feed both on plant and prey, often maintain a close relationship with certain host plants. In this study, we aimed to select a suitable mirid predatory bug for aphid control in sweet pepper. Four species were compared: Macrolophus

  7. Enhancement of resistance to aphids by introducing the snowdrop lectin gene gna into maize plants

    Indian Academy of Sciences (India)

    Zhaoyu Wang; Kewei Zhang; Xiaofen Sun; Kexuan Tang; Juren Zhang

    2005-12-01

    In order to enhance the resistance to pests, transgenic maize (Zea mays L.) plants from elite inbred lines containing the gene encoding snowdrop lectin (Galanthus nivalis L. agglutinin; GNA) under control of a phloemspecific promoter were generated through the Agrobacterium tumefaciens-mediated method. The toxicity of GNA-expressing plants to aphids has also been studied. The independently derived plants were subjected to molecular analyses. Polymerase chain reaction (PCR) and Southern blot analyses confirmed that the gna gene was integrated into maize genome and inherited to the following generations. The typical Mendelian patterns of inheritance occurred in most cases. The level of GNA expression at 0.13%–0.28% of total soluble protein was observed in different transgenic plants. The progeny of nine GNA-expressing independent transformants that were derived separately from the elite inbred lines DH4866, DH9942, and 8902, were selected for examination of resistance to aphids. These plants synthesized GNA at levels above 0.22% total soluble protein, and enhanced resistance to aphids was demonstrated by exposing the plants to corn leaf aphid (Rhopalosiphum maidis Fitch) under greenhouse conditions. The nymph production was significantly reduced by 46.9% on GNA-expressing plants. Field evaluation of the transgenic plants supported the results from the inoculation trial. After a series of artificial self-crosses, some homozygous transgenic maize lines expressing GNA were obtained. In the present study, we have obtained new insect-resistant maize material for further breeding work.

  8. Enhancement of resistance to aphids by introducing the snowdrop lectin gene gna into maize plants.

    Science.gov (United States)

    Wang, Zhaoyu; Zhang, Kewei; Sun, Xiaofen; Tang, Kexuan; Zhang, Juren

    2005-12-01

    In order to enhance the resistance to pests, transgenic maize (Zea mays L.) plants from elite inbred lines containing the gene encoding snowdrop lectin (Galanthus nivalis L. agglutinin; GNA) under control of a phloem-specific promoter were generated through the Agrobacterium tumefaciens-mediated method. The toxicity of GNA-expressing plants to aphids has also been studied. The independently derived plants were subjected to molecular analyses. Polymerase chain reaction (PCR) and Southern blot analyses confirmed that the gna gene was integrated into maize genome and inherited to the following generations. The typical Mendelian patterns of inheritance occurred in most cases. The level of GNA expression at 0.13%-0.28% of total soluble protein was observed in different transgenic plants. The progeny of nine GNA-expressing independent transformants that were derived separately from the elite inbred lines DH4866, DH9942, and 8902, were selected for examination of resistance to aphids. These plants synthesized GNA at levels above 0.22% total soluble protein, and enhanced resistance to aphids was demonstrated by exposing the plants to corn leaf aphid (Rhopalosiphum maidis Fitch) under greenhouse conditions. The nymph production was significantly reduced by 46.9% on GNA-expressing plants. Field evaluation of the transgenic plants supported the results from the inoculation trial. After a series of artificial self-crosses, some homozygous transgenic maize lines expressing GNA were obtained. In the present study, we have obtained new insect-resistant maize material for further breeding work.

  9. [Study on transformation of snowdrop lectin gene to chrysanthemum and aphid resistance of the transgenic plants].

    Science.gov (United States)

    Wang, Guan-Lin; Liu, Yan-Hong; Guo, Shao-Hua; Wang, Yu; Ji, Yan; Fang, Hong-Jun

    2004-12-01

    Agrobacterium-mediated transformation in chrysanthemum was studied to prevent the insect pest of aphid (Mizus persicae). The gna gene was successfully transferred into chrysanthemum by leaf dish, and 93 transgenic clones were obtained. The highest transformation frequency 11.21% was achieved on the optimization facts, which were medium YEB with pH5.6, bacterial concentration OD600 = 0.4, precultivation for one day, cocultivation for four days, the cocultivation media supplemented with GA3 0.5 mg/L and leaf explants growed for 45 days. The results from PCR and FQ-PCR analysis confirmed that gna gene was integrated into the genome of chrysanthemum plants. The insect bioassay with aphid showed that the aphid resistance of different transgenic plants was difference, and the rate of aphid population inhibition of them were from 10% to 84% with an average rate of 39.4%. The leaf-extracts from different transgenic plants showed varying actinties in red-blood cell bioassay.

  10. Effect of vermicompost and cucumber cultivar on population growth attributes of the melon aphid (Hemiptera: Aphididae).

    Science.gov (United States)

    Razmjou, J; Mohammadi, M; Hassanpour, M

    2011-08-01

    Worldwide, the developing industry of cucumbers (Cucumis sativus L.) grown in greenhouses is threatened by damage from sucking pests, especially aphids. Among these, the melon aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is the most serious. We tested the effect of two cucumber cultivars ('Royal' and'Storm') and three vermicompost concentrations (0 [control], 20, and 30%) in field soil on the development and fecundity rates of A. gossypii, by using a randomized complete block design with four replicates as a factorial experiment. The developmental times of nymphs reared on plants grown into the three vermicompost concentrations ranged from 5.5 (0%) to 8.7 (30%) d (on Storm) and from 4.3 (0%) to 7 (30%) d (on Royal). The developmental time of melon aphid's nymphs was greatest on plants grown in the culture medium with 30% vermicompost rate and least on plants reared in the soil without vermicompost. The intrinsic rate of natural increase (r,,) of A. gossypii ranged from 0.204 d(-1) on plants grown in the soil amended with 30% vermicompost rate (on Storm seedlings) to 0.458 d(-1) on plants grown in the soil without vermicompost (on Royal seedlings). Accordingly, our findings confirm that a combination of a low level of vermicompost and a partially resistant cucumber cultivar might play an important role in managing this aphid on cucumbers in greenhouses.

  11. A possible novel black aphid control approach using plant growth regulators

    Science.gov (United States)

    The black pecan aphid, Melanocallis caryaefoliae (Davis) (Hemiptera: Aphididae), elicits localized chlorotic injury to pecan foliage in order to feed, thereby accelerating leaf senescence and defoliation. The action of certain plant growth regulators (i.e., forchlorfenuron, gibberellic acid and avi...

  12. Evaluation of extraction procedures for 2-DE analysis of aphid proteins.

    Science.gov (United States)

    Yiou, Pan; Shaoli, An; Kebin, Li; Tao, Wang; Kui, Fang; Hua, Zhang; Yu, Sun; Xun, Yang; Jinghui, Xi

    2013-02-01

    Protein sample preparation is a crucial step in a 2-DE proteomics approach. In order to establish a routine protocol for the application of proteomics analysis to aphids, this study focuses on the specific protein extraction problems in insect tissues and evaluates four methods to bypass them. The approaches of phenol extraction methanol/ammonium acetate precipitation (PA), TCA/acetone precipitation, PEG precipitation, and no precipitation were evaluated for proteins isolation and purification from apterous adult aphids, Sitobion avenae. For 2-DE, the PA protocol was optimal, resulting in good IEF and clear spots. PA method yielded the greatest amount of protein and displayed most protein spots in 2-DE gels, as compared with the TCA/acetone precipitation, PEG precipitation and no precipitation protocols. Analysis of protein yield, image quality and spot numbers demonstrate that the TCA/acetone precipitation protocol is a reproducible and reliable method for extracting proteins from aphids. The PEG precipitation approach is a newly developed protein extraction protocol for aphids, from which more unique protein spots can be detected, especially for detection of acid proteins. These protocols are expected to be applicable to other insects or could be of interest to laboratories involved in insect proteomics, despite the amounts and types of interfering compounds vary considerably in different insects.

  13. Registration of ‘Wyandot-14’ soybean with resistance to soybean aphid and powdery mildew

    Science.gov (United States)

    ‘Wyandot-14’ soybean [Glycine max (L.) Merr.] with resistance to soybean aphid biotypes 1 and 2 and resistance to powdery mildew was jointly released by the USDA-Agricultural Research Service and The Ohio Agricultural Research and Development Center (OARDC) as a late maturity group (MG) II (2.9) foo...

  14. The aphid Melanaphis sacchari and the weed Sorghum almum – Partners in crime

    Science.gov (United States)

    Sugarcane yellow leaf virus (SCYLV), the causal agent of yellow leaf disease of sugarcane, is widespread in Florida and vectored by the aphid Melanaphis sacchari. Sugarcane was the only known natural host of SCYLV in the USA until 2015 when a new natural host was found for this virus in Florida: Sor...

  15. Secretome of fungus-infected aphids documents high pathogen activity and weak host response

    DEFF Research Database (Denmark)

    Grell, Morten Nedergaard; Jensen, Annette Bruun; Olsen, Peter B.

    2011-01-01

    Discovery of novel secretome proteins contributes to the understanding of host-pathogen interactions. Here we report a rich diversity of secreted proteins from the interaction between grain aphids (host, insect order Hemiptera) and fungi of the order Entomophthorales (insect pathogens), made poss...

  16. Metagenomic Analysis of Cucumber RNA from East Timor Reveals an Aphid lethal paralysis virus Genome

    Science.gov (United States)

    Maina, Solomon; Edwards, Owain R.; de Almeida, Luis; Ximenes, Abel

    2017-01-01

    ABSTRACT We present here the first complete genomic Aphid lethal paralysis virus (ALPV) sequence isolated from cucumber plant RNA from East Timor. We compare it with two complete ALPV genome sequences from China, and one each from Israel, South Africa, and the United States. It most closely resembled the Chinese isolate LGH genome. PMID:28082492

  17. Response of Green Peach Aphids and Other Arthropods to Garlic Intercropped with Tobacco

    NARCIS (Netherlands)

    Lai, R.; You, M.; Lotz, L.A.P.; Vasseur, L.

    2011-01-01

    The green peach aphid, Myzus persicae (Sulzer), is an insect pest that causes extensive damage to tobacco (Nicotiana tabacum L.) in China. Field trials were conducted in 2008 and 2009 at Longyan in the Fujian Province (China) to evaluate the effects of garlic (Allium sativum L.) as a deterrent to gr

  18. Insecticidal activity of rhamnolipid isolated from pseudomonas sp. EP-3 against green peach aphid (Myzus persicae).

    Science.gov (United States)

    Kim, Seul Ki; Kim, Young Cheol; Lee, Sunwoo; Kim, Jin Cheol; Yun, Mi Young; Kim, In Seon

    2011-02-09

    Microorganisms capable of growth on oils are potential sources of biopesticides, as they produce complex molecules such as biosurfactants and lipopeptides. These molecules have antimicrobial activity against plant pathogens, but few data are available on their insecticidal activity. The present study describes the insecticidal activity of a rhamnolipid isolated from diesel oil-degrading Pseudomonas sp. EP-3 (EP-3). The treatment of cell-free supernatants of EP-3 grown on glucose-mineral medium for 96 h led to > 80% mortality of aphids (Myzus persicae) within 24 h. Bioassay-guided chromatography coupled with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MADLDI-TOF MS) and (¹H, ¹³C) nuclear magnetic resonance (NMR) analyses was employed to isolate and identify the EP-3 insecticidal metabolites. Dirhamnolipid, with molecular formulas of C₃₂H₅₈O₁₃ and C₃₄H₆₂O₁₃, was identified as a main metabolite exhibiting insecticidal activity against aphids. Dirhamnolipid showed a dose-dependent mortality against aphids, producing about 50% mortality at 40 μg/mL and 100% mortality at 100 μg/mL. Microscopy analyses of aphids treated with dirhamnolipid revealed that dirhamnolipid caused insect death by affecting cuticle membranes. This is the first report of rhamnolipid as an insecticidal metabolite against M. persicae. Rhamnolipid shows potential for use as a pesticide to control agricultural pests.

  19. Wild tomato leaf extracts for spider mite and cowpea aphid control.

    Science.gov (United States)

    Antonious, George F; Kamminga, Katherine; Snyder, John C

    2014-01-01

    Glandular trichomes on the leaves of wild tomato, L. hirsutum f. hirsutum Mull, also known as Solanum habrochaites (Solanaceae), synthesize and accumulate high levels of methyl ketones (MKs). L. hirsutum accession LA 407, having high concentration of MKs, was grown from seeds under greenhouse conditions. Four MKs (2-undecanone, 2-dodecanone, 2-tridecanone, and 2-pentadecanone) were screened for their toxicity to spider mites, Tetranychus urticae Koch and cowpea aphids, Aphis craccivora Koch. The objectives of this investigation were to: (1) develop a bioassay for testing MKs on spider mite and cowpea aphid mortality and (2) compare the efficacies of wild tomato leaf crude extracts and pure standard materials of MKs against spider mite and cowpea aphid mortality. Our results revealed that spider mites are most sensitive to 2-tridecanone (LC50 = 0.08 μmole cm(-2) of treated leaf surface) and least sensitive to 2-undecanone (LC50 = 1.5 μmole cm(-2) of treated leaf surface) 4 h after treatment. Similarly, 2-tridecanone caused greatest mortality (LC50 = 0.2 μmole cm(-2) of treated leaf surface), whereas 2-undecanone caused the lowest morality (LC50 = 0.48 μmole cm(-2) of treated surface) of cowpea aphid. We concluded that all MKs tested in this investigation are toxic to spider mites and aphids. 2-Tridecanone is more effective in killing mites and aphids compared to other MKs. Toxicity of crude extracts, prepared from the leaves of L. hirsutum accession LA 407, to spider mites and cowpea aphids revealed greater mortality compared to a combined mixture of MKs standard material (used at the same concentration as found on LA 407 leaves). This indicates that in addition to MKs, other unidentified compounds in LA 407 leaf extract also have pesticidal properties. Accordingly, leaf extracts of LA 407 could be explored in crop protection, and they might open a new area of MK formulations and discovery of biorational alternatives for pest control in agricultural fields.

  20. Within-plant distribution of cotton aphid (Hemiptera: Aphididae in cotton cultivars with colored fibers

    Directory of Open Access Journals (Sweden)

    Francisco S. Fernandes

    2012-09-01

    Full Text Available We describe the vertical and horizontal distribution of the cotton aphid Aphis gossypii Glover within a cotton plant in two cotton (Gossypium hirsutum Linnaeus cultivars (BRS Safira and BRS Rubí with colored fiber over the time. Measurements of aphid population dynamics and distribution in the cotton plants were recorded in intervals of seven days. The number of apterous or alate aphids and their specific locations were recorded, using as a reference point the location of nodes on the mainstem of the plant and also those on the leaves present on branches and fruit structures. The number of apterous aphids found on the cultivar BRS Safira (56,515 aphids was greater than that found on BRS Rubí (50,537 aphids. There was no significant difference between the number of alate aphids found on the cultivars BRS Safira (365 aphids/plant and BRS Rubí (477 aphids/plant. There were interactions between cotton cultivar and plant age, between plant region and plant age, and between cultivar and plant region for apterous aphids. The results of this study are of great importance in improving control strategies for A. gossypii in the naturally-colored cotton cultivars BRS Safira and BRS Rubí.Nós descrevemos a distribuição vertical e horizontal do pulgão do algodoeiro Aphis gossypii Glover dentro da planta de algodão (Gossypium hirsutum Linnaeus, em dois cultivares com fibras coloridas (BRS Safira and BRS Rubí ao longo do seu desenvolvimento. Medidas de dinâmicas de populações e distribuição de A. gossypii nas plantas de algodão foram registradas em intervalos de sete dias. O número de afídeos ápteros ou alados e suas localizações específicas foram registrados, usando-se como ponto de referência a localização do nó no caule principal da planta e também aqueles presentes nas folhas de ramos e estruturas frutíferas. O número de afídeos ápteros encontrados na cultivar BRS Safira (56.515 afídeos foi maior do que o encontrado na BRS Rub

  1. Radiosensitivity study in the germination and growth of the pea Pisum sativum L, with seeds exposed to gamma radiation; Estudio de radiosensibilidad en la germinacion y crecimiento de la arveja Pisum sativum L, con semillas expuestas a radiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Ilguan, J.; Carrasco, J.; Marquez, V., E-mail: ilguanjanneth@gmail.com [Escuela Superior Politecnica de Chimborazo, Facultad de Ciencias, Panamericana Sur Km 1 1/2, ECO60155 Riobamba (Ecuador)

    2016-10-15

    Seeds of Pisum sativum L. were irradiated in a {sup 60}Co irradiator belonging to the Subsecretaria de Control y Aplicaciones Nucleares del Ecuador (SCAN), the dose rate at the irradiation time was 4.86 Gy/min. The seeds were grouped in packs of 100 units and exposed at doses of 20, 40, 60, 80, 100, 120, 140, 160, 180 and 200 Gy. The number of effective germinations, the days for germination, the main stem thickness, the number of branches and the size of the plant were evaluated. To validate the experimentation, the data were analyzed statistically by tests of homogeneity of variances, way ANOVA and Scheffe analysis to each variable. The number of effective germinations was given to 100% for 20 and 40 Gy then decreases to a higher dose reaching 20% to 200 Gy, being the average of the proof near to 90%. Increased germination stimulation at treatment at 20 Gy with an average of 5.0 days was evidenced. Treatment at doses of 20, 40 and 60 Gy generate a plant size greater than the proof whose mean is 68.30 cm. The mean number of branches of the proof is 5.3 with a standard deviation of 0.675, which is greater at doses of 20 and 40 Gy. In the study, is concluded that better results are obtained when irradiating seeds Pisum sativum L, between 20 and 60 Gy. (Author)

  2. Aboveground feeding by soybean aphid, Aphis glycines, affects soybean cyst nematode, Heterodera glycines, reproduction belowground.

    Directory of Open Access Journals (Sweden)

    Michael T McCarville

    Full Text Available Heterodera glycines is a cyst nematode that causes significant lost soybean yield in the U.S. Recent studies observed the aphid Aphis glycines and H. glycines interacting via their shared host, soybean, Glycine max. A greenhouse experiment was conducted to discern the effect of A. glycines feeding on H. glycines reproduction. An H. glycines-susceptible cultivar, Kenwood 94, and a resistant cultivar, Dekalb 27-52, were grown in H. glycines-infested soil for 30 and 60 d. Ten days after planting, plants were infested with either zero, five, or ten aphids. At 30 and 60 d, the number of H. glycines females and cysts (dead females and the number of eggs within were counted. In general, H. glycines were less abundant on the resistant than the susceptible cultivar, and H. glycines abundance increased from 30 to 60 d. At 30 d, 33% more H. glycines females and eggs were produced on the resistant cultivar in the ten-aphid treatment compared to the zero-aphid treatment. However, at 30 d the susceptible cultivar had 50% fewer H. glycines females and eggs when infested with ten aphids. At 60 d, numbers of H. glycines females and cysts and numbers of eggs on the resistant cultivar were unaffected by A. glycines feeding, while numbers of both were decreased by A. glycines on the susceptible cultivar. These results indicate that A. glycines feeding improves the quality of soybean as a host for H. glycines, but at higher herbivore population densities, this effect is offset by a decrease in resource quantity.

  3. Resistance of Wheat Accessions to the English Grain Aphid Sitobion avenae.

    Directory of Open Access Journals (Sweden)

    Xiang-Shun Hu

    Full Text Available The English grain aphid, Sitobion avenae, is a major pest species of wheat crops; however, certain varieties may have stronger resistance to infestation than others. Here, we investigated 3 classical resistance mechanisms (antixenosis, antibiosis, and tolerance by 14 wheat varieties/lines to S. avenae under laboratory and field conditions. Under laboratory conditions, alatae given the choice between 2 wheat varieties, strongly discriminated against certain varieties. Specifically, the 'Amigo' variety had the lowest palatability to S. avenae alatae of all varieties. 'Tm' (Triticum monococcum, 'Astron,' 'Xanthus,' 'Ww2730,' and 'Batis' varieties also had lower palatability than other varieties. Thus, these accessions may use antibiosis as the resistant mechanism. In contrast, under field conditions, there were no significant differences in the number of alatae detected on the 14 wheat varieties. One synthetic line (98-10-30, a cross between of Triticum aestivum (var. Chris and Triticum turgidum (var. durum hybridization had low aphid numbers but high yield loss, indicating that it has high antibiosis, but poor tolerance. In comparison, 'Amigo,' 'Xiaoyan22,' and some '186Tm' samples had high aphid numbers but low yield loss rates, indicating they have low antibiosis, but good tolerance. Aphid population size and wheat yield loss rates greatly varied in different fields and years for '98-10-35,' 'Xiaoyan22,' 'Tp,' 'Tam200,' 'PI high,' and other '186Tm' samples, which were hybrid offspring of T. aestivum and wheat related species. Thus, these germplasm should be considered for use in future studies. Overall, S. avenae is best adapted to 'Xinong1376,' because it was the most palatable variety, with the greatest yield loss rates of all 14 wheat varieties. However, individual varieties/lines influenced aphid populations differently in different years. Therefore, we strongly recommend a combination of laboratory and long-term field experiments in

  4. A comparison of protein extraction methods suitable for gel-based proteomic studies of aphid proteins.

    Science.gov (United States)

    Cilia, M; Fish, T; Yang, X; McLaughlin, M; Thannhauser, T W; Gray, S

    2009-09-01

    Protein extraction methods can vary widely in reproducibility and in representation of the total proteome, yet there are limited data comparing protein isolation methods. The methodical comparison of protein isolation methods is the first critical step for proteomic studies. To address this, we compared three methods for isolation, purification, and solubilization of insect proteins. The aphid Schizaphis graminum, an agricultural pest, was the source of insect tissue. Proteins were extracted using TCA in acetone (TCA-acetone), phenol, or multi-detergents in a chaotrope solution. Extracted proteins were solubilized in a multiple chaotrope solution and examined using 1-D and 2-D electrophoresis and compared directly using 2-D Difference Gel Electrophoresis (2-D DIGE). Mass spectrometry was used to identify proteins from each extraction type. We were unable to ascribe the differences in the proteins extracted to particular physical characteristics, cell location, or biological function. The TCA-acetone extraction yielded the greatest amount of protein from aphid tissues. Each extraction method isolated a unique subset of the aphid proteome. The TCA-acetone method was explored further for its quantitative reliability using 2-D DIGE. Principal component analysis showed that little of the variation in the data was a result of technical issues, thus demonstrating that the TCA-acetone extraction is a reliable method for preparing aphid proteins for a quantitative proteomics experiment. These data suggest that although the TCA-acetone method is a suitable method for quantitative aphid proteomics, a combination of extraction approaches is recommended for increasing proteome coverage when using gel-based separation techniques.

  5. Tritrophic associations and taxonomic notes on Lysiphlebus fabarum (Marshall (Hymenoptera: Braconidae: Aphidiinae, a keystone aphid parasitoid in Iran

    Directory of Open Access Journals (Sweden)

    Rakhshani Ehsan

    2013-01-01

    Full Text Available An investigation of host associations, distribution and types of reproduction (sexual, asexual of Lysiphlebus fabarum (Marshall across 20 provinces of Iran during 2006-2011 was undertaken. The parasitoid was reared from three groups of host aphids belonging to genera Aphis and Brachycaudus, and occasional host aphid genera. Aphis craccivora Koch was the most frequent host aphid for L. fabarum on various host plants, including economically important crops. The field sex ratio generally favored females, but in some cases, only thelytokous (uniparental populations were found. In those cases, the host was always an Aphis species. Specimens reared from Brachycaudus aphids were all biparental, indicating the presence of a sibling biological species. Overall analysis of diagnostic morphological characters in the forewing indicated intra-specific variability in forewing marginal setae as well as variations in length of the R1 vein. [Projekat Ministarstva nauke Republike Srbije, br. 43001

  6. Shallot Aphids, Myzus ascalonicus, in Strawberry: Biocontrol Potential of Three Predators and Three Parasitoids

    DEFF Research Database (Denmark)

    Enkegaard, Annie; Sigsgaard, Lene; Kristensen, Kristian

    2013-01-01

    The parasitization capacity of 3 parasitoids and the predation capacity of 3 predators towards the shallot aphid, Myzus ascalonicus Doncaster (Homoptera: Aphididae), on strawberry, Fragaria x ananassa Duchesne (Rosales: Rosaceae) cv. Honeoye, were examined in laboratory experiments. In Petri dish...

  7. The same allele of translation initiation factor 4E mediates resistance against two potyvirus species in Pisum sativum

    DEFF Research Database (Denmark)

    Bruun-Rasmussen, Marianne; Møller, I S; Tulinius, G;

    2007-01-01

    Pathogenicity of two sequenced isolates of Bean yellow mosaic virus (BYMV) was established on genotypes of Pisum sativum L. reported to carry resistance genes to BYMV and other potyviruses. Resistance to the white lupin strain of BYMV (BYMV-W) is inherited as a recessive gene named wlv that maps ...... of the VPg coding region. These results suggested that VPg determined pathogenicity on plants carrying the wlv resistance gene and that wlv corresponded to the sbm1 allele of eIF4E......Pathogenicity of two sequenced isolates of Bean yellow mosaic virus (BYMV) was established on genotypes of Pisum sativum L. reported to carry resistance genes to BYMV and other potyviruses. Resistance to the white lupin strain of BYMV (BYMV-W) is inherited as a recessive gene named wlv that maps......-W-susceptible and â€"resistant P. sativum genotypes revealed a polymorphism correlating with the resistance profile. Expression of eIF4E from susceptible plants in resistant plants facilitated BYMV-W infection in inoculated leaves. When cDNA of BYMV-W was agroinoculated, resistance mediated by the wlv gene frequently...

  8. Genetic diversity and population structure of Pisum sativum accessions for marker-trait association of lipid content

    Institute of Scientific and Technical Information of China (English)

    Sajjad Ahmad; Simerjeet Kaur; Neil Dylan Lamb-Palmer; Mark Lefsrud; Jaswinder Singh

    2015-01-01

    Field pea (Pisum sativum L.) is an important protein-rich pulse crop produced globally. Increasing the lipid content of Pisum seeds through conventional and contemporary molecular breeding tools may bring added value to the crop. However, knowledge about genetic diversity and lipid content in field pea is limited. An understanding of genetic diversity and population structure in diverse germplasm is important and a prerequisite for genetic dissection of complex characteristics and marker-trait associations. Fifty polymorphic microsatellite markers detecting a total of 207 alleles were used to obtain information on genetic diversity, population structure and marker-trait associations. Cluster analysis was performed using UPGMA to construct a dendrogram from a pairwise similarity matrix. Pea genotypes were divided into five major clusters. A model-based population structure analysis divided the pea accessions into four groups. Percentage lipid content in 35 diverse pea accessions was used to find potential associations with the SSR markers. Markers AD73, D21, and AA5 were significantly associated with lipid content using a mixed linear model (MLM) taking population structure (Q) and relative kinship (K) into account. The results of this preliminary study suggested that the population could be used for marker-trait association mapping studies.

  9. Efficacy of Vermicompost against fertilizers on Cicer and Pisum and on population diversity of N2 fixing bacteria.

    Science.gov (United States)

    Sinha, Jayanta; Biswas, Chanchal Kumar; Ghosh, Arup; Saha, Amit

    2010-05-01

    Vermicompost is a very important biofertilizer produced through the artificial cultivation of worms i.e. Vermiculture. Vermicompost is enriched with all beneficial soil bacteria and also contain many of the essential plant nutrients like N, P, K and micronutrients. It increases soil aeration, texture and jilt. In this work, study is being carried out to find out the effect of different fertilizers such as DAF, FYM and Vermicompost on various morphological parameters and on the in vitro growth of bacterial colonies and its diversity in relation to two important leguminous plants such as Pisum sp. and Cicer sp. Results showed that plant grown in Vermicompost pretreated soil exhibited maximum increase in all morphological parameters such as root length, shoot length, number of root branches, number of stem branches, number of leaves, number of flowers, number of pods and number of root nodules in four months sampling in comparison to untreated, FYM treated and DAP treated soils. Further in Vermicompost pretreated soil, number of N2 fixing bacterial colony was maximum and showed highest diversity indices (1.6 and 0.99 and 2.0 and 0.99 for Cicer sp. and Pisum sp. respectively) than FYM, DAP and untreated control. Thus not only does the Vermicompost stimulate plant growth but also it increases the N2 fixing bacterial population in soil and also its diversity.

  10. Isoenzymes of superoxide dismutase in nodules of Phaseolus vulgaris L. , Pisum sativum L. , and Vigna unguiculata (L. ) Walp

    Energy Technology Data Exchange (ETDEWEB)

    Becana, M.; Paris, F.J.; Sandalio, L.M.; Del Rio, L.A. (IRNA, Salamanca (Spain) Unidad de Bioquimica Vegetal, Granada (Spain))

    1989-08-01

    The activity and isozymic composition of superoxide dismutase were determined in nodules of Phaseolus vulgaris L., Pisum sativum L., and Vigna unguiculata (L.) Walp. A Mn-SOD was present in Rhizobium and two in Bradyrhizobium and bacteroids. Nodule mitochondria from all three legume species had a single Mn-SOD with similar relative mobility, whereas the cytosol contained several CuZn-SODs: two in Phaseolus and Pisum, and four in Vigna. In the cytoplasm of V. unguiculata nodules, a Fe-containing SOD was also present, with an electrophoretic mobility between those of CuZn- and Mn-SODs, and an estimated molecular weight of 57,000. Total SOD activity of the soluble fraction of host cells, expressed on a nodule fresh weight basis, exceeded markedly that of bacteroids. Likewise, specific SOD activities of free-living bacteria were superior or equal to those of their symbiotic forms. Soluble extracts of bacteria and bacteroids did not show peroxidase activity, but the nodule cell cytoplasm contained diverse peroxidase isozymes which were readily distinguishable from leghemoglobin components by electrophoresis. Data indicated that peroxidases and leghemoglobins did not significantly interfere with SOD localization on gels. Treatment with chloroform-ethanol scarcely affected the isozymic pattern of SODs and peroxidases, and had limited success in the removal of leghemoglobin.

  11. Genetic diversity and population structure of Pisum sativum accessions for marker-trait association of lipid content

    Directory of Open Access Journals (Sweden)

    Sajjad Ahmad

    2015-06-01

    Full Text Available Field pea (Pisum sativum L. is an important protein-rich pulse crop produced globally. Increasing the lipid content of Pisum seeds through conventional and contemporary molecular breeding tools may bring added value to the crop. However, knowledge about genetic diversity and lipid content in field pea is limited. An understanding of genetic diversity and population structure in diverse germplasm is important and a prerequisite for genetic dissection of complex characteristics and marker-trait associations. Fifty polymorphic microsatellite markers detecting a total of 207 alleles were used to obtain information on genetic diversity, population structure and marker-trait associations. Cluster analysis was performed using UPGMA to construct a dendrogram from a pairwise similarity matrix. Pea genotypes were divided into five major clusters. A model-based population structure analysis divided the pea accessions into four groups. Percentage lipid content in 35 diverse pea accessions was used to find potential associations with the SSR markers. Markers AD73, D21, and AA5 were significantly associated with lipid content using a mixed linear model (MLM taking population structure (Q and relative kinship (K into account. The results of this preliminary study suggested that the population could be used for marker-trait association mapping studies.

  12. Genetic diversity and population structure of Pisum sativum accessions for marker-trait association of lipid content

    Institute of Scientific and Technical Information of China (English)

    Sajjad; Ahmad; Simerjeet; Kaur; Neil; Dylan; Lamb-Palmer; Mark; Lefsrud; Jaswinder; Singh

    2015-01-01

    Field pea(Pisum sativum L.) is an important protein-rich pulse crop produced globally. Increasing the lipid content of Pisum seeds through conventional and contemporary molecular breeding tools may bring added value to the crop. However, knowledge about genetic diversity and lipid content in field pea is limited. An understanding of genetic diversity and population structure in diverse germplasm is important and a prerequisite for genetic dissection of complex characteristics and marker-trait associations. Fifty polymorphic microsatellite markers detecting a total of 207 alleles were used to obtain information on genetic diversity, population structure and marker-trait associations. Cluster analysis was performed using UPGMA to construct a dendrogram from a pairwise similarity matrix. Pea genotypes were divided into five major clusters. A model-based population structure analysis divided the pea accessions into four groups. Percentage lipid content in 35 diverse pea accessions was used to find potential associations with the SSR markers. Markers AD73, D21, and AA5 were significantly associated with lipid content using a mixed linear model(MLM) taking population structure(Q) and relative kinship(K) into account. The results of this preliminary study suggested that the population could be used for marker-trait association mapping studies.

  13. QTL Mapping by SLAF-seq and Expression Analysis of Candidate Genes for Aphid Resistance in Cucumber

    Directory of Open Access Journals (Sweden)

    Danna Liang

    2016-07-01

    Full Text Available Cucumber, a very important vegetable crop worldwide, is easily damaged by pests. Aphid is one of the most serious cucumber pests and frequently cause severe damage to commercially produced crops. Understanding the genetic mechanisms underlying pest resistance is important for aphid-resistant cucumber varieties breeding. In this study, two parental cucumber lines, JY30 (aphid susceptible and EP6392 (aphid resistant, and pools of resistant and susceptible (n = 50 each plants from 1000 F2 individuals derived from crossing JY30 with EP6392, were used to detect genomic regions associated with aphid resistance in cucumbers. The analysis was performed using specific length amplified fragment sequencing (SLAF-seq, bulked segregant analysis (BSA and single nucleotide polymorphism index (SNP-index methods. A main effect QTL (quantitative trait locus of 0.31 Mb on Chr5, including 43 genes, was identified by association analysis. Sixteen of the 43 genes were identified as potentially associated with aphid resistance through gene annotation analysis. The effect of aphid infestation on the expression of these candidate genes screened by SLAF-seq was investigated in EP6392 plants by qRT-PCR. The results indicated that 7 genes including encoding transcription factor MYB59-like (Csa5M641610.1, auxin transport protein BIG-like (Csa5M642140.1, F-box/kelch-repeat protein At5g15710-like (Csa5M642160.1, transcription factor HBP-1a-like (Csa5M642710.1, beta-glucan-binding protein (Csa5M643380.1, endo-1,3(4-beta-glucanase 1-like (Csa5M643880.1, and proline-rich receptor-like protein kinase PERK10-like (Csa5M643900.1, out of the 16 genes were down regulated after aphid infestation, whereas 5 genes including encoding probable leucine-rich repeat receptor-like serine/threonine-protein kinase At5g15730-like (Csa5M642150.1, Stress-induced protein KIN2 (Csa5M643240.1 and Csa5M643260.1, F-box family protein (Csa5M643280.1, F-box/kelch-repeat protein (Csa5M643290.1, were up

  14. Development and characterization of Brassica juncea – fruticulosa introgression lines exhibiting resistance to mustard aphid (Lipaphis erysimi Kalt

    Directory of Open Access Journals (Sweden)

    Atri Chhaya

    2012-11-01

    Full Text Available Abstract Background Mustard aphid is a major pest of Brassica oilseeds. No source for aphid resistance is presently available in Brassica juncea . A wild crucifer, Brassica fruticulosa is known to be resistant to mustard aphid. An artificially synthesized amphiploid, AD-4 (B. fruticulosa × B. rapa var. brown sarson was developed for use as a bridge species to transfer fruticulosa resistance to B. juncea. Using the selfed backcross we could select a large number of lines with resistance to mustard aphid. This paper reports cytogenetic stability of introgression lines, molecular evidence for alien introgression and their reaction to mustard aphid infestation. Results Majority of introgression lines had expected euploid chromosome number(2n= 36, showed normal meiosis and high pollen grain fertility. Well-distributed and transferable simple-sequence repeats (SSR markers for all the 18 B. juncea chromosomes helped to characterize introgression events. Average proportions of recipient and donor genome in the substitution lines were 49.72 and 35.06%, respectively. Minimum alien parent genome presence (27.29% was observed in the introgression line, Ad3K-280 . Introgressed genotypes also varied for their resistance responses to mustard aphid infestations under artificial release conditions for two continuous seasons. Some of the test genotypes showed consistent resistant reaction. Conclusions B.juncea-fruticulosa introgression set may prove to be a very powerful breeding tool for aphid resistance related QTL/gene discovery and fine mapping of the desired genes/QTLs to facilitate marker assisted transfer of identified gene(s for mustard aphid resistance in the background of commercial mustard genotypes.

  15. Aphid effects on rhizosphere microorganisms and microfauna depend more on barley growth phase than on soil fertilization

    DEFF Research Database (Denmark)

    Madsen, Mette Vestergård; Strandmark, Lisa Bjørnlund; Christensen, Søren

    2004-01-01

    . Contrary to this, 1 week after spike emergence numbers of bacteria, fungal feeding nematodes and Protozoa were higher in rhizospheres of plants subjected to aphids probably because aphids enhanced root mortality and root decomposition. Protozoa and bacterial feeding nematodes were stimulated at different...... experimental conditions with nematodes being the dominant bacterial grazers at N fertilization and Protozoa in the NP treatment before spike emergence....

  16. Biological control of cotton aphid (Aphis gossypii Glover) in cotton (inter)cropping systems in China; a simulation study.

    OpenAIRE

    Xia, J

    1997-01-01

    Cotton aphid ( Aphis gossypii Glover) is the key insect pest of seedling cotton ( Gossypium hirsutum L. ) in China, particularly in the North China cotton region. The resulting annual losses amount to 10-15% of the attainable yield. Sole reliance on insecticides against the cotton aphid in the past four decades has brought about a rapid development of insecticide resistance, serious outbreaks of key pests, resurgence of secondary pests, and risk for man and environment. Biological control of ...

  17. Effect of epicuticular waxes from triticale on the feeding behaviour and mortality of the grain aphid, Sitobion avenae (Fabricius (Hemiptera: Aphididae

    Directory of Open Access Journals (Sweden)

    Wójcicka Agnieszka

    2016-01-01

    Full Text Available Surface waxes from wax-covered triticale plants (RAH 122 were sprayed on plants of the waxless genotype RAH 366 or the surface waxes were used to make artificial diet preparations. The results were significant increases in the mortality of apterous adults of the grain aphid Sitobion avenae (Fabricius (Hemiptera: Aphididae at all concentrations tested in comparison with those aphids which fed on the control plants or aphids which were reared on the diets. In the choice tests, most aphids settled on plants without surface waxes or on diet preparations which did not have surface waxes (the controls. When the concentration of the surface waxes was increased on one of the plants or surface waxes were increased in the diet preparation, the number of wandering aphids increased. Those aphids which did not wander were mainly on the waxless control plants or on the waxless diet preparations. Aphids did settle on those plants or on the diet preparations which had 100 and 1,000 μg · g-1 of surface wax. The aphids rarely settled on the diet preparations containing 10,000 μg ∙ g-1 of surface waxes. From these observations it appears that surface waxes can act as a feeding deterrent. Since aphids on plants with surface waxes, or aphids which settled on diet preparations with surface waxes, started to die earlier than aphids fed only the control plants or the control diet preparations, it is possible that the surface waxes had a toxic effect that led to early mortality. Thus, it can be said that the surface waxes caused feeding deterrence and had a toxic effect on the aphids.

  18. Kinetics of Ca2+- and ATP-dependent, voltage-controlled anion conductance in the plasma membrane of mesophyll cells of Pisum sativum

    NARCIS (Netherlands)

    Elzenga, J.T.M.; van Volkenburgh, E.

    1997-01-01

    Whole-cell patch-clamp techniques were used to measure anion currents through the plasma membrane of protoplasts of mesophyll cells of expanding pea (Pisum sativum L.) leaves. Voltage-induced changes of the currents could be modelled with single exponential activation and deactivation kinetics. The

  19. Probiotic effects of beta-glucuronidase on the peach-potato aphid Myzus persicae (Aphididae).

    Science.gov (United States)

    Cherqui, A; Alla, S; Saguez, J; Doury, G; Sangwan-Norreel, B S; Giordanengo, P

    2003-12-01

    beta-glucuronidase (GUS) is a reporter protein commonly expressed in transgenic plants allowing the visualization of the transformed individuals. In our recent work, we showed that consumption of transformed potato plants expressing this GUS enzyme improves performance of the phloem feeding aphid Myzus persicae. Those results led us to the conclusion that the expression of GUS in potato plants might be responsible for the probiotic effect measured in feeding aphids. In the present paper, artificial diets were used to provide active GUS (10 and 500 microg ml(-1)), inactivated heated GUS (500 microg ml(-1)), glucuronic acid (10, 100 and 500 microg ml(-1)), and bovine serum albumin (500 microg ml(-1)) to M. persicae. Our results reveal that these chemicals provided as food intake might influence the biological parameters of this aphid. Experiments showed a probiotic effect of 500 microg ml(-1) GUS diet, resulting in reduced larval mortality, and increased adult reproduction period and fecundity, which led to an increased population growth potential (r(m)=0.17+/-0.01 versus r(m)=0.12+/-0.03 for aphids fed on control diet). A lower amount of added GUS led to fewer variations, biological parameters being only slightly altered (r(m)=0.14+/-0.03). Statistically similar alterations of the biological parameters were obtained when comparing aphids fed on the diet added with inactivated GUS or the non-structural bovine serum albumin protein (r(m)=0.15+/-0.02 and 0.14+/-0.03, respectively). Feeding assays conducted with glucuronic acid supplemented diets enhanced longevity and nymph production of the adult aphids and reduced larval mortality, resulting in r(m)=0.15+/-0.02 for the highest dose (500 microg ml(-1)). Although 100 microg ml(-1) glucuronate diet did not induce any effect on M. persicae (r(m)=0.12+/-0.03), aphids fed on 10 microg ml(-1) glucuronate diet exhibited unexpected reduced demographic parameters (r(m)=0.10+/-0.03). Immuno-histological analysis showed GUS

  20. Colonization of the biomass energy crop miscanthus by the three aphid species, Aphis fabae, Myzus persicae, and Rhopalosiphum padi.

    Science.gov (United States)

    Coulette, Q; Couty, A; Lasue, P; Rambaud, Z C; Ameline, A

    2013-04-01

    Miscanthus is a perennial C4-grass that has received much interest as a potential of impact on the local agroecosytem. In this context, laboratory experiments were conducted to investigate the potential colonization of this new exotic plant species by three of the main aphid pest species of common crops in Picardie, northern France. In host preference experiments, the two polyphagous aphid species studied, Aphis fabae (Scop) and Myzus persicae (Sulzer), exhibited an xclusive preference for their host plant, whereas the cereal specialist Rhopalosiphum padi (L.) showed no preference between its host plant and miscanthus. When assessed by electrical penetration graph technique, plant tissue probing activity by all three species always was characterized by pathway phases including potential drops that are typically associated to the transmission of noncirculative viruses. Phloem ingestion was observed in 5% of the polyphagous aphid individuals tested and in 20% of the R. padi tested. Aphids kept in clip-cages on miscanthus had a low survival rate and were unable to reproduce. These results demonstrate that miscanthus is not a suitable host for these three main aphid pest species but could act as a potential host for some viruses transmitted in a noncirculative manner and also in a circulative nonpropagative manner. The use of miscanthus as a barrier crop to limit the flow of aphid vectors and their phytoviruses is discussed.

  1. Transgenic Expression of a Functional Fragment of Harpin Protein Hpa1 in Wheat Represses English Grain Aphid Infestation

    Institute of Scientific and Technical Information of China (English)

    XU Man-yu; ZHOU Ting; ZHAO Yan-ying; LI Jia-bao; XU Heng; DONG Han-song; ZHANG Chun-ling

    2014-01-01

    The harpin protein Hpa1 produced by the rice bacterial blight pathogen promotes plant growth and induces plant resistance to pathogens and insect pests. The region of 10-42 residues (Hpa110-42) in the Hpa1 sequence is critical as the isolated Hpa110-42 fragment is 1.3-7.5-fold more effective than the full length in inducing plant growth and resistance. Here we report that transgenic expression of Hpa110-42 in wheat induces resistance to English grain aphid, a dominant species of wheat aphids. Hpa110-42-induced resistance is effective to inhibit the aphid behavior in plant preference at the initial colonization stage and repress aphid performances in the reproduction, nymph growth, and instar development on transgenic plants. The resistance characters are correlated with enhanced expression of defense-regulatory genes (EIN2, PP2-A, and GSL10) and consistent with induced expression of defense response genes (Hel, PDF1.2, PR-1b, and PR-2b). As a result, aphid infestations are alleviated in transgenic plants. The level of Hpa110-42-induced resistance in regard to repression of aphid infestations is equivalent to the effect of chemical control provided by an insecticide. These results suggested that the defensive role of Hpa110-42 can be integrated into breeding germplasm of the agriculturally signiifcant crop with a great potential of the agricultural application.

  2. Comparative transcriptional analysis of asexual and sexual morphs reveals possible mechanisms in reproductive polyphenism of the cotton aphid.

    Directory of Open Access Journals (Sweden)

    Li-Jun Liu

    Full Text Available Aphids, the destructive insect pests in the agriculture, horticulture and forestry, are capable of reproducing asexually and sexually upon environmental change. However, the molecular basis of aphid reproductive mode switch remains an enigma. Here we report a comparative analysis of differential gene expression profiling among parthenogenetic females, gynoparae and sexual females of the cotton aphid Aphis gossypii, using the RNA-seq approach with next-generation sequencing platforms, followed by RT-qPCR. At the cutoff criteria of fold change ≥2 and P<0.01, we identified 741 up- and 879 down-regulated genes in gynoparae versus parthenogenetic females, 2,101 up- and 2,210 down-regulated genes in sexual females compared to gynoparae, and 1,614 up- and 2,238 down-regulated genes in sexual females relative to parthenogenetic females. Gene ontology category and KEGG pathway analysis suggest the involvement of differentially expressed genes in multiple cellular signaling pathways into the reproductive mode transition, including phototransduction, cuticle composition, progesterone-mediated oocyte maturation and endocrine regulation. This study forms a basis for deciphering the molecular mechanisms underlying the shift from asexual to sexual reproduction in the cotton aphid. It also provides valuable resources for future studies on this host-alternating aphid species, and the insight into the understanding of reproductive mode plasticity in different aphid species.

  3. Infection of host plants by Cucumber mosaic virus increases the susceptibility of Myzus persicae aphids to the parasitoid Aphidius colemani.

    Science.gov (United States)

    Mauck, Kerry E; De Moraes, Consuelo M; Mescher, Mark C

    2015-06-04

    Plant viruses can profoundly alter the phenotypes of their host plants, with potentially far-reaching implications for ecology. Yet few studies have explored the indirect, host-mediated, effects of plant viruses on non-vector insects. We examined how infection of Cucurbita pepo plants by Cucumber mosaic virus (CMV) impacted the susceptibility of aphids (Myzus persicae) to attack by the parasitoid wasp Aphidius colemani. In semi-natural foraging assays, we observed higher rates of aphid parasitism on infected plants compared to healthy plants. Subsequent experiments revealed that this difference is not explained by different attack rates on plants differing in infection status, but rather by the fact that parasitoid larvae successfully complete their development more often when aphid hosts feed on infected plants. This suggests that the reduced nutritional quality of infected plants as host for aphids--documented in previous studies--compromises their ability to mount effective defenses against parasitism. Furthermore, our current findings indicate that the aphid diet during parasitoid development (rather than prior to wasp oviposition) is a key factor influencing resistance. These findings complement our previous work showing that CMV-induced changes in host plant chemistry alter patterns of aphid recruitment and dispersal in ways conducive to virus transmission.

  4. Proteomic analysis of albumin and globulin fractions of pea (Pisum sativum L. seeds

    Directory of Open Access Journals (Sweden)

    Jerzy Dziuba

    2014-06-01

    Full Text Available Background. Proteomic analysis is emerging as a highly useful tool in food research, including studies of food allergies. Two-dimensional gel electrophoresis involving isoelectric focusing and sodium dodecyl sulfate polyacrylamide gel electrophoresis is the most effective method of separating hundreds or even thousands of proteins. In this study, albumin and globulin tractions of pea seeds cv. Ramrod were subjected to proteomic analysis. Selected potentially alergenic proteins were identified based on their molecular weights and isoelectric points. Material and methods. Pea seeds (Pisum sativum L. cv. Ramrod harvested over a period of two years (Plant Breeding Station in Piaski-Szelejewo were used in the experiment. The isolated albumins, globulins and legumin and vicilin fractions of globulins were separated by two-dimensional gel electrophoresis. Proteomic images were analysed in the ImageMaster 2D Platinum program with the use of algorithms from the Melanie application. The relative content, isoelectric points and molecular weights were computed for all identified proteins. Electrophoregrams were analysed by matching spot positions from three independent replications. Results. The proteomes of albumins, globulins and legumin and vicilin fractions of globulins produced up to several hundred spots (proteins. Spots most characteristic of a given fraction were identified by computer analysis and spot matching. The albumin proteome accumulated spots of relatively high intensity over a broad range of pi values of -4.2-8.1 in 3 molecular weight (MW ranges: I - high molecular-weight albumins with MW of -50-110 kDa, II - average molecular-weight albumins with MW of -20-35 kDa, and III - low molecular-weight albumins with MW of -13-17 kDa. 2D gel electrophoregrams revealed the presence of 81 characteristic spots, including 24 characteristic of legumin and 14 - of vicilin. Conclusions. Two-dimensional gel electrophoresis proved to be a useful tool for

  5. Protecting crops from non-persistently aphid-transmitted viruses: a review on the use of barrier plants as a management tool.

    Science.gov (United States)

    Hooks, Cerruti R R; Fereres, Alberto

    2006-09-01

    Barrier plants are a management tool based on secondary plants used within or bordering a primary crop for the purpose of disease control. Aphid-transmitted viruses account for approximately 50% of the 600 known viruses with an invertebrate vector. Barrier plants may act as real natural sinks for non-persistent aphid-transmitted viruses and have proved in the past to be an effective crop management strategy to protect against virus infection. Increasing the knowledge on aphid host seeking and flying behaviour, and on how barrier plants may affect the behaviour of aphids and their natural enemies will allow further development of this environmentally-friendly habitat manipulation strategy. An ideal plant barrier should be a non-host for the virus and the vector, but appealing to aphid landing and attractive to their natural enemies and should allow sufficient residence time to allow aphid probing before taking-off occurs. In this review, we have addressed why aphids are manageable by barrier cropping, the mechanisms by which barrier plants affect the occurrence of non-persistently aphid-transmitted viruses and the limitations of using barrier plants as a virus control strategy. Finally, we have pointed out future directions of research that should be conducted to integrate barrier cropping with other disease management strategies, and optimise and extend the use of barrier plants as a strategy for managing aphid-transmitted virus diseases.

  6. Eggs of Mallada desjardinsi (Neuroptera: Chrysopidae) are protected by ants: the role of egg stalks in ant-tended aphid colonies.

    Science.gov (United States)

    Hayashi, Masayuki; Nomura, Masashi

    2014-08-01

    In ant-aphid mutualisms, ants usually attack and exclude enemies of aphids. However, larvae of the green lacewing Mallada desjardinsi (Navas) prey on ant-tended aphids without being excluded by ants; these larvae protect themselves from ants by carrying aphid carcasses on their backs. Eggs of M. desjardinsi laid at the tips of stalks have also been observed in ant-tended aphid colonies in the field. Here, we examined whether the egg stalks of M. desjardinsi protect the eggs from ants and predators. When exposed to ants, almost all eggs with intact stalks were untouched, whereas 50-80% of eggs in which stalks had been severed at their bases were destroyed by ants. In contrast, most eggs were preyed upon by larvae of the lacewing Chrysoperla nipponensis (Okamoto), an intraguild predator of M. desjardinsi, regardless of whether their stalks had been severed. These findings suggest that egg stalks provide protection from ants but not from C. nipponensis larvae. To test whether M. desjardinsi eggs are protected from predators by aphid-tending ants, we introduced C. nipponensis larvae onto plants colonized by ant-tended aphids. A significantly greater number of eggs survived in the presence of ants because aphid-tending ants excluded larvae of C. nipponensis. This finding indicates that M. desjardinsi eggs are indirectly protected from predators by ants in ant-tended aphid colonies.

  7. Predation of the Peach Aphid Myzus persicae by the mirid Predator Macrolophus pygmaeus on Sweet Peppers: Effect of Prey and Predator Density

    Directory of Open Access Journals (Sweden)

    Lara De Backer

    2015-06-01

    Full Text Available Integrated Pest Management strategies are widely implemented in sweet peppers. Aphid biological control on sweet pepers includes curative applications of parasitoids and generalist predators, but with limited efficiency. Macrolophus pygmaeus is a zoophytophagous predator which has been reported to predate on aphids, but has traditionally been used to control other pests, including whiteflies. In this work, we evaluate the effectiveness of M. pygmaeus in controlling Myzus persicae (Homoptera: Aphididae by testing different combinations of aphid and predator densities in cage-experiments under greenhouse conditions. The impact of the presence of an alternative factitious prey (E. kuehniella eggs was also investigated. Macrolophus pygmaeus, at densities of four individuals/plant, caused rapid decline of newly established aphid populations. When aphid infestations were heavy, the mirid bug reduced the aphid numbers but did not fully eradicate aphid populations. The availability of a factitious prey did not influence M. pygmaeus predation on aphids. Based on our data, preventive application of M. pygmaeus, along with a supplementary food source , is recommended to control early infestations of aphids.

  8. Performance and feeding behaviour of two biotypes of the black currant-lettuce aphid, Nasonovia ribisnigri, on resistant and susceptible Lactuca sativa near-isogenic lines.

    Science.gov (United States)

    ten Broeke, Cindy J M; Dicke, Marcel; van Loon, Joop J A

    2013-10-01

    The black currant-lettuce aphid, Nasonovia ribisnigri, is an important pest of cultivated lettuce, Lactuca sativa. Since 1982, the control of this aphid on lettuce is largely based on host plant resistance, conferred by the Nr gene, introgressed from Lactuca virosa. The resistance mechanism remains to be identified. N. ribisnigri populations virulent on the Nr-based resistance in lettuce have emerged in several locations in Europe since 2007. The objective of this study was to investigate the resistance mechanism mediated by the Nr gene in lettuce by detailed studies of aphid feeding behaviour and performance. Both avirulent (Nr:0) and virulent (Nr:1)biotypes of N. ribisnigri were studied on five resistant and two susceptible near isogenic lines (NILs). In addition, survival and colony development were quantified.Nr:0 aphids showed a strong decrease in sieve element ingestion and took longer to accept a sieve element on resistant NILs compared with susceptible NILs, and no aphids survived on the resistant NIL. Nr:1 aphids fed and performed equally well on the resistant and susceptible NILs. The resistance mechanism against Nr:0 aphids encoded by the Nr gene seems to be located in the phloem, although we also observed differences in feeding behaviour during the pathway phase to the phloem. Nr:1 aphids were highly virulent to the resistance conferred by the Nr gene. The consequences of the appearance of Nr:1 aphids for control of N. ribisnigri are discussed.

  9. Temperature-Dependent Fecundity and Life Table of the Fennel Aphid Hyadaphis foeniculi (Passerini (Hemiptera: Aphididae.

    Directory of Open Access Journals (Sweden)

    Francisco S Ramalho

    Full Text Available Hyadaphis foeniculi (Passerini (Hemiptera: Aphididae is a cosmopolitan species and the main pest of fennel in northeastern Brazil. Understanding the relationship between temperature variations and the population growth rates of H. foeniculi is essential to predict the population dynamics of this aphid in the fennel crop. The aim of this study was to measure the effect of constant temperature on the adult prereproductive period and the life table fertility parameters (infinitesimal increase ratio (rm, gross reproduction rate (GRR, net reproduction rate (R0, finite increase ratio (λ, generation time (GT, the time required for the population to double in the number of individuals (DT, and the reproduction value (RVx of the fennel pest H. foeniculi. The values of lx (survival of nymphs at age x increased as the temperature rose from 15 to 28°C and fell at 30°C, whereas mx (number of nymphs produced by each nymph of age x increased from 15 to 25°C and fell at 28 and 30°C. The net reproduction rates (R0 of populations of H. foeniculi increased with temperature and ranged from 1.9 at 15°C to 12.23 at 28°C for each generation. The highest population increase occurred with the apterous aphids at 28°C. The rate of population increase per unit time (rm (day ranged from 0.0033 (15°C to 0.1995 (28°C. The highest values of rm were recorded at temperatures of 28°C and 30°C. The rm values were a good fit to the models tested, with R2 > 0.91 and R2adj > 0.88. The models tested (Davidson, Sharpe and DeMichele modified by Schoolfield et al., Logan et al., Lamb, and Briere et al. were very good fits for the rm values observed, with R2 > 0.91 and R2adj > 0.88. The only exception was the Davidson model. Of the parameters studied, the reproductive capacity was higher in the apterous aphids, with the unique exception of daily fecundity at 28°C, which was higher in the alate aphids of H. foeniculi. Parameters relating to the age-specific fertility table for

  10. Temperature-Dependent Fecundity and Life Table of the Fennel Aphid Hyadaphis foeniculi (Passerini) (Hemiptera: Aphididae).

    Science.gov (United States)

    Ramalho, Francisco S; Malaquias, José B; Lira, Aline C S; Oliveira, Flávia Q; Zanuncio, José C; Fernandes, Francisco S

    2015-01-01

    Hyadaphis foeniculi (Passerini) (Hemiptera: Aphididae) is a cosmopolitan species and the main pest of fennel in northeastern Brazil. Understanding the relationship between temperature variations and the population growth rates of H. foeniculi is essential to predict the population dynamics of this aphid in the fennel crop. The aim of this study was to measure the effect of constant temperature on the adult prereproductive period and the life table fertility parameters (infinitesimal increase ratio (rm), gross reproduction rate (GRR), net reproduction rate (R0), finite increase ratio (λ), generation time (GT), the time required for the population to double in the number of individuals (DT), and the reproduction value (RVx)) of the fennel pest H. foeniculi. The values of lx (survival of nymphs at age x) increased as the temperature rose from 15 to 28°C and fell at 30°C, whereas mx (number of nymphs produced by each nymph of age x) increased from 15 to 25°C and fell at 28 and 30°C. The net reproduction rates (R0) of populations of H. foeniculi increased with temperature and ranged from 1.9 at 15°C to 12.23 at 28°C for each generation. The highest population increase occurred with the apterous aphids at 28°C. The rate of population increase per unit time (rm) (day) ranged from 0.0033 (15°C) to 0.1995 (28°C). The highest values of rm were recorded at temperatures of 28°C and 30°C. The rm values were a good fit to the models tested, with R2 > 0.91 and R2adj > 0.88. The models tested (Davidson, Sharpe and DeMichele modified by Schoolfield et al., Logan et al., Lamb, and Briere et al.) were very good fits for the rm values observed, with R2 > 0.91 and R2adj > 0.88. The only exception was the Davidson model. Of the parameters studied, the reproductive capacity was higher in the apterous aphids, with the unique exception of daily fecundity at 28°C, which was higher in the alate aphids of H. foeniculi. Parameters relating to the age-specific fertility table for H

  11. Vat, an Amazing Gene Conferring Resistance to Aphids and Viruses They Carry: From Molecular Structure to Field Effects

    Science.gov (United States)

    Boissot, Nathalie; Schoeny, Alexandra; Vanlerberghe-Masutti, Flavie

    2016-01-01

    We review half a century of research on Cucumis melo resistance to Aphis gossypii from molecular to field levels. The Vat gene is unique in conferring resistance to both A. gossypii and the viruses it transmits. This double phenotype is aphid clone-dependent and has been observed in 25 melon accessions, mostly from Asia. It is controlled by a cluster of genes including CC-NLR, which has been characterized in detail. Copy-number polymorphisms (for the whole gene and for a domain that stands out in the LLR region) and single-nucleotide polymorphisms have been identified in the Vat cluster. The role of these polymorphisms in plant/aphid interactions remains unclear. The Vat gene structure suggests a functioning with separate recognition and response phases. During the recognition phase, the VAT protein is thought to interact (likely indirectly) with an aphid effector introduced during cell puncture by the aphid. A few hours later, several miRNAs are upregulated in Vat plants. Peroxidase activity increases, and callose and lignin are deposited in the walls of the cells adjacent to the stylet path, disturbing aphid behavior. In aphids feeding on Vat plants, Piwi-interacting RNA-like sequences are abundant and the levels of other miRNAs are modified. At the plant level, resistance to aphids is quantitative (aphids escape the plant and display low rates of reproduction). Resistance to viruses is qualitative and local. Durability of NLR genes is highly variable. A. gossypii clones are adapted to Vat resistance, either by introducing a new effector that interferes with the deployment of plant defenses, or by adapting to the defenses it triggered. Viruses transmitted in a non-persistent manner cannot adapt to Vat resistance. At population level, Vat reduces aphid density and genetic diversity. The durability of Vat resistance to A. gossypii populations depends strongly on the agro-ecosystem, including, in particular, the presence of other cucurbit crops serving as

  12. Vat, an amazing gene conferring resistance to aphids and viruses they carry: from molecular structure to field effects

    Directory of Open Access Journals (Sweden)

    Nathalie Boissot

    2016-09-01

    Full Text Available We review half a century of research on Cucumis melo resistance to Aphis gossypii from molecular to field levels. The Vat gene is unique in conferring resistance to both A. gossypii and the viruses it transmits. This double phenotype is aphid clone-dependent and has been observed in 25 melon accessions, mostly from Asia. It is controlled by a cluster of genes including CC-NLR, which has been characterized in detail. Copy-number polymorphisms (for the whole gene and for a domain that stands out in the LLR region and single-nucleotide polymorphisms have been identified in the Vat cluster. The role of these polymorphisms in plant aphid/interactions remains unclear. The Vat gene structure suggests a functioning with separate recognition and response phases. During the recognition phase, the VAT protein is thought to interact (likely indirectly with an aphid effector introduced during cell puncture by the aphid. A few hours later, several miRNAs are upregulated in Vat plants. Peroxidase activity increases, and callose and lignin are deposited in the walls of the cells adjacent to the stylet path, disturbing aphid behavior. In aphids feeding on Vat plants, Piwi-interacting RNA-like sequences are abundant and the levels of other miRNAs are modified. At the plant level, resistance to aphids is quantitative (aphids escape the plant and display low rates of reproduction. Resistance to viruses is qualitative and local.Durability of NLR genes is highly variable. A. gossypii clones are adapted to Vat resistance, either by introducing a new effector that interferes with the deployment of plant defenses, or by adapting to the defenses it triggered. Viruses transmitted in a non-persistent manner cannot adapt to Vat resistance. At population level, Vat reduces aphid density and genetic diversity. The durability of Vat resistance to A. gossypii populations depends strongly on the agro-ecosystem, including, in particular, the presence of other cucurbit crops

  13. Fitness Effects of Food Resources on the Polyphagous Aphid Parasitoid, Aphidius colemani Viereck (Hymenoptera: Braconidae: Aphidiinae).

    Science.gov (United States)

    Charles, Jennifer J; Paine, Timothy D

    2016-01-01

    Conservation biological control involving the polyphagous aphid parasitoid, Aphidius colemani Viereck, may include provisioning resources from a variety of plant sources. The fitness of adult A. colemani was enhanced with the provision of food resources such as floral nectar from a range of both native and introduced plant species and aphid honeydew under laboratory conditions. However, enhanced fitness appeared to be species specific rather than associated with the whether the plant was a native or an introduced species. Parasitoid survival and fecundity were enhanced significantly in response to the availability of floral nectar and honeydew compared to the response to available extrafloral nectar. These positive effects on the parasitoid's reproductive activity can improve the effectiveness of conservation biological control in nursery production systems because of the abundance and diversity of floral resources within typical production areas. Additionally, surrounding areas of invasive weeds and native vegetation could serve as both floral resources and honeydew food resources for A. colemani.

  14. Bisorbicillinoids produced by the fungus Trichoderma citrinoviride affect feeding preference of the aphid Schizaphis graminum.

    Science.gov (United States)

    Evidente, Antonio; Andolfi, Anna; Cimmino, Alessio; Ganassi, Sonia; Altomare, Claudio; Favilla, Mara; De Cristofaro, Antonio; Vitagliano, Silvia; Agnese Sabatini, Maria

    2009-05-01

    We report the effects of some bisorbicillinoids isolated from biomass of the fungus Trichoderma citrinoviride on settling and feeding preference of the aphid Schizaphis graminum. Purification of the fungal metabolites was carried out by a combination of column chromatography and thin-layer chromatography using direct and reverse phases. Chemical identification was performed by spectroscopic methods including nuclear magnetic resonance and mass spectrometry. The identified bisorbicillinoids appeared to be bislongiquinolide, its 16,17-dihydro derivative, trichodimerol, and dihydrotrichodimerol. A feeding preference test with alate morphs of S. graminum was used to identify the active fractions. Among the four bisorbicillinoids, dihydrotrichodimerol and bislongiquinolide influenced aphid feeding preference, restraining specimens from settling on leaves treated with metabolites. Taste neurons sensitive to these compounds, particularly to bislongiquinolide, were located on tarsi of the S. graminum alate morphs.

  15. Aphids (Hemiptera: Aphidomorpha of the Botanic Garden of the Jagiellonian University, Kraków*

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    Starowicz Marzena

    2015-12-01

    Full Text Available The paper presents results of faunistic investigations of aphids (Aphidomorpha in the Botanic Garden of the Jagiellonian University, Kraków, in the Kraków – Wieluń Upland. During two seasons of research (2011, 2012 two aphid species from the family Adelgidae and 50 species from the family Aphididae, associated with 66 host plants were recorded. The following species – Eriosoma anncharlotteae Danielsson, 1979, Capitophorus elaeagni (Del Guercio, 1894, Rhopalosiphoninus (Neorhopalosiphoninus staphyleae staphyleae (Koch, 1854, Eulachnus brevipilosus Börner, 1940 and E. cembrae Börner, 1950 – are new for the Kraków – Wieluń Upland. Seven of the species recorded are regarded as alien to Poland.

  16. Non-pest prey do not disrupt aphid predation by a web-building spider.

    Science.gov (United States)

    Welch, K D; Whitney, T D; Harwood, J D

    2016-02-01

    A generalist predator's ability to contribute to biological control is influenced by the decisions it makes during foraging. Predators often use flexible foraging tactics, which allows them to pursue specific types of prey at the cost of reducing the likelihood of capturing other types of prey. When a pest insect has low nutritional quality or palatability for a predator, the predator is likely to reject that prey in favour of pursuing alternative, non-pest prey. This is often thought to limit the effectiveness of generalist predators in consuming aphids, which are of low nutritional quality for many generalist predators. Here, we report behavioural assays that test the hypothesis that the generalist predator, Grammonota inornata (Araneae: Linyphiidae), preferentially forages for a non-pest prey with high nutritional quality (springtails), and rejects a pest prey with low nutritional quality (aphids). In no-choice assays, molecular gut-content analysis revealed that spiders continued to feed on the low-quality aphids at high rates, even when high-quality springtails were readily available. When provided a choice between aphids and springtails in two-way choice tests, spiders did not show the expected preference for springtails. Decision-making by spiders during foraging therefore appears to be sub-optimal, possibly because of attraction to the less frequently encountered of two preys as part of a dietary diversification strategy. These results indicate that behavioural preferences alone do not necessarily compromise the pest-suppression capacity of natural enemies: even nutritionally sub-optimal pest prey can potentially be subject to predation and suppression by natural enemies.

  17. Functional evaluation of proteins in watery and gel saliva of aphids

    OpenAIRE

    Aart Jan Eeuwe Van Bel; Torsten Will

    2016-01-01

    AbstractGel and watery saliva are regarded as key players in aphid-pIant interactions. The salivary composition seems to be influenced by the variable environment encountered by the stylet tip. Milieu sensing has been postulated to provide information needed for proper stylet navigation and for the required switches between gel and watery saliva secretion during stylet progress. Both the chemical and physical factors involved in sensing of the stylet’s environment are discussed. To investigat...

  18. Rothamsted’s aphid-resistant wheat – a turning point for GMOs?

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    Lynas Mark

    2012-10-01

    Full Text Available Abstract Rothamsted Research mounted a successful counter-campaign in response to a threat by environmental protesters to destroy their research project examining aphid-resistant genetically modified (GM wheat. This involved the use of online media, petitions, and other tools, by which researchers engaged directly with media and the general public in defense of their work. Lessons are suggested for other researchers in the controversial field of GM plant breeding.

  19. Use of ryegrass strips to enhance biological control of aphids by ladybirds in wheat fields

    Institute of Scientific and Technical Information of China (English)

    Zhao-Ke Dong; Feng-Juan Gao; Run-Zhi Zhang

    2012-01-01

    Non-crop habitats may play a vital role in conservation biological control.This study tested the effect of ryegrass (Lolium muitiflorum L.) strips on aphid and ladybird populations in adjacent winter wheat fields.The field experiment was conducted in three ryegrass-margin wheat plots and three control plots in 2010 in North China.In spring,the same aphid species,Sitobion miscanthi (Takahashi),was found in both the ryegrass strips and wheat plots.The population density of ladybirds in the ryegrass strips (3.5±0.9/m2) was significantly higher than in the wheat plots (1.5±0.5/m2).We cut the ryegrass,forcing the ladybirds to migrate to the wheat fields.Three and eight days after cutting the ryegrass,the aphid numbers in the ryegrass-margin wheat plots decreased significantly:they were 19.9% and 53.6%,respectively,lower than in control plots.In the early period of ladybird population development,the percentage of larvae was greater in the ryegrass-margin wheat plots than in controls,and the peak number of pupae in the ryegrass-margin wheat plots occurred 5 days earlier than in the control plots.The results suggest that ryegrass strips may promote the development of ladybird populations.Cutting ryegrass can manipulate ladybirds to enhance biological aphid control in wheat fields.The efficiency of this management approach is discussed.

  20. Biological Control of Aphid Using Fungal Culture and Culture Filtrates of Beauveria bassiana

    OpenAIRE

    Kim, Jeong Jun; Jeong, Gayoung; Han, Ji Hee; Lee, Sangyeob

    2013-01-01

    Aphids are one of the most destructive pests in crop production such as pepper, cucumber, and eggplants. The importance of entomopathogenic fungi as alternative pest control agents is increasing. Conidia of entomopathogenic fungi are influenced by environmental conditions, such as temperature and relative humidity, and cause slow and fluctuating mortality. These factors have prevented wider application and use of biocontrol agents. For investigation of means of mitigation of such problems, we...

  1. Analysis of carotenoid compounds in aphids by Raman imaging and mass spectrometry

    OpenAIRE

    sprotocols

    2015-01-01

    Authors: Pierre Brat, Jean Christophe Valmalette, Christian Mertz, George de Sousa, Aviv Dombrovsky, Maria Capovilla & Alain Robichon ### Abstract Carotenoids are compounds synthesized in plants, bacteria and fungi, closely associated to the chlorophyll to perform photosynthesis. A spectacular evolutionary achievement allowed the aphid to produce carotenoids obviously by lateral transfer of genes from fungi. We have recently documented that these molecules are involved in photo c...

  2. The entomopathogenic fungal endophytes Purpureocillium lilacinum (formerly Paecilomyces lilacinus) and Beauveria bassiana negatively affect cotton aphid reproduction under both greenhouse and field conditions.

    Science.gov (United States)

    Castillo Lopez, Diana; Zhu-Salzman, Keyan; Ek-Ramos, Maria Julissa; Sword, Gregory A

    2014-01-01

    The effects of two entomopathogenic fungal endophytes, Beauveria bassiana and Purpureocillium lilacinum (formerly Paecilomyces lilacinus), were assessed on the reproduction of cotton aphid, Aphis gossypii Glover (Homoptera:Aphididae), through in planta feeding trials. In replicate greenhouse and field trials, cotton plants (Gossypium hirsutum) were inoculated as seed treatments with two concentrations of B. bassiana or P. lilacinum conidia. Positive colonization of cotton by the endophytes was confirmed through potato dextrose agar (PDA) media plating and PCR analysis. Inoculation and colonization of cotton by either B. bassiana or P. lilacinum negatively affected aphid reproduction over periods of seven and 14 days in a series of greenhouse trials. Field trials were conducted in the summers of 2012 and 2013 in which cotton plants inoculated as seed treatments with B. bassiana and P. lilacinum were exposed to cotton aphids for 14 days. There was a significant overall effect of endophyte treatment on the number of cotton aphids per plant. Plants inoculated with B. bassiana had significantly lower numbers of aphids across both years. The number of aphids on plants inoculated with P. lilacinum exhibited a similar, but non-significant, reduction in numbers relative to control plants. We also tested the pathogenicity of both P. lilacinum and B. bassiana strains used in the experiments against cotton aphids in a survival experiment where 60% and 57% of treated aphids, respectively, died from infection over seven days versus 10% mortality among control insects. Our results demonstrate (i) the successful establishment of P. lilacinum and B. bassiana as endophytes in cotton via seed inoculation, (ii) subsequent negative effects of the presence of both target endophytes on cotton aphid reproduction using whole plant assays, and (iii) that the P. lilacinum strain used is both endophytic and pathogenic to cotton aphids. Our results illustrate the potential of using these

  3. The entomopathogenic fungal endophytes Purpureocillium lilacinum (formerly Paecilomyces lilacinus and Beauveria bassiana negatively affect cotton aphid reproduction under both greenhouse and field conditions.

    Directory of Open Access Journals (Sweden)

    Diana Castillo Lopez

    Full Text Available The effects of two entomopathogenic fungal endophytes, Beauveria bassiana and Purpureocillium lilacinum (formerly Paecilomyces lilacinus, were assessed on the reproduction of cotton aphid, Aphis gossypii Glover (Homoptera:Aphididae, through in planta feeding trials. In replicate greenhouse and field trials, cotton plants (Gossypium hirsutum were inoculated as seed treatments with two concentrations of B. bassiana or P. lilacinum conidia. Positive colonization of cotton by the endophytes was confirmed through potato dextrose agar (PDA media plating and PCR analysis. Inoculation and colonization of cotton by either B. bassiana or P. lilacinum negatively affected aphid reproduction over periods of seven and 14 days in a series of greenhouse trials. Field trials were conducted in the summers of 2012 and 2013 in which cotton plants inoculated as seed treatments with B. bassiana and P. lilacinum were exposed to cotton aphids for 14 days. There was a significant overall effect of endophyte treatment on the number of cotton aphids per plant. Plants inoculated with B. bassiana had significantly lower numbers of aphids across both years. The number of aphids on plants inoculated with P. lilacinum exhibited a similar, but non-significant, reduction in numbers relative to control plants. We also tested the pathogenicity of both P. lilacinum and B. bassiana strains used in the experiments against cotton aphids in a survival experiment where 60% and 57% of treated aphids, respectively, died from infection over seven days versus 10% mortality among control insects. Our results demonstrate (i the successful establishment of P. lilacinum and B. bassiana as endophytes in cotton via seed inoculation, (ii subsequent negative effects of the presence of both target endophytes on cotton aphid reproduction using whole plant assays, and (iii that the P. lilacinum strain used is both endophytic and pathogenic to cotton aphids. Our results illustrate the potential of

  4. Isolated and Community Contexts Produce Distinct Responses by Host Plants to the Presence of Ant-Aphid Interaction: Plant Productivity and Seed Viability

    Science.gov (United States)

    Santiago, Graziele Silva; Zurlo, Luana Fonseca; Ribas, Carla Rodrigues; Carvalho, Rafaela Pereira; Alves, Guilherme Pereira; Carvalho, Mariana Comanucci Silva; Souza, Brígida

    2017-01-01

    Ant-aphid interactions may affect host plants in several ways, however, most studies measure only the amount of fruit and seed produced, and do not test seed viability. Therefore, the aim of this study was to assess the effects of the presence of ant-aphid interactions upon host plant productivity and seed viability in two different contexts: isolated and within an arthropod community. For this purpose we tested the hypothesis that in both isolated and community contexts, the presence of an ant-aphid interaction will have a positive effect on fruit and seed production, seed biomass and rate of seed germination, and a negative effect on abnormal seedling rates, in comparison to plants without ants. We performed a field mesocosm experiment containing five treatments: Ant-aphid, Aphid, Community, Ant-free community and Control. We counted fruits and seeds produced by each treatment, and conducted experiments for seed biomass and germinability. We found that in the community context the presence of an ant-aphid interaction negatively affected fruit and seed production. We think this may be because aphid attendance by tending-ants promotes aphid damage to the host plant, but without an affect on seed weight and viability. On the other hand, when isolated, the presence of an ant-aphid interaction positively affected fruit and seed production. These positive effects are related to the cleaning services offered to aphids by tending-ants, which prevent the development of saprophytic fungi on the surface of leaves, which would cause a decrease in photosynthetic rates. Our study is important because we evaluated some parameters of plant fitness that have not been addressed very well by other studies involving the effects of ant-aphid interactions mainly on plants with short life cycles. Lastly, our context dependent approach sheds new light on how ecological interactions can vary among different methods of crop management. PMID:28141849

  5. Can snow depth be used to predict the distribution of the high Arctic aphid Acyrthosiphon svalbardicum (Hemiptera: Aphididae on Spitsbergen?

    Directory of Open Access Journals (Sweden)

    Ávila-Jiménez María L

    2011-10-01

    Full Text Available Abstract Background The Svalbard endemic aphid Acyrthosiphon svalbardicum (Heikinheimo, 1968 is host specific to Dryas octopetala L. ssp octopetala (Rosaceae. It has been hypothesized that the aphid is present on those areas with a thin winter snow cover and which therefore clear of snow earlier in the season. This early snow clearance results in a longer growing period and allows the aphid to experience at least the minimum number of degree days required to complete its life cycle. However, this hypothesis lacked a detailed field validation. We aimed to test the relationship between the aphid distribution and time of snow clearance at landscape scale, mapping snow depth at peak of snow accumulation for the two succeeding years 2009 and 2010 and examining site occupancy and plant phenology the following summers. Additionally, the distribution range mapped by Strathdee & Bale (1995 was revisited to address possible changes in range along the coast of the fjord. Results A linear relation between snow depth and timing of snow melt was found but with strong inter-annual and landscape variation. Both snow depth and plant phenology were found to affect patch occupancy. In August, the aphid, at the three life stages scored (viviparae, oviparae/males and eggs, was present most frequently in those D. octopetala patches with the most advanced plant phenology and which showed shallower snow depths in spring. However, many patches predicted to contain aphids were empty. The aphid distribution range has expanded 4.7 km towards the fjord mouth from 1995. Conclusions Snow depth alone, and hence date of snow clearance, cannot precisely define species distribution at landscape scale, as this cannot explain why are they unoccupied patches under shallow snow depths with advanced plant phenology. We nonetheless present a model Arctic system that could form the basis for long term monitoring for climate- driven species shifts.

  6. miRNA-mediated auxin signalling repression during Vat-mediated aphid resistance in Cucumis melo.

    Science.gov (United States)

    Sattar, Sampurna; Addo-Quaye, Charles; Thompson, Gary A

    2016-06-01

    Resistance to Aphis gossypii in melon is attributed to the presence of the single dominant R gene virus aphid transmission (Vat), which is biologically expressed as antibiosis, antixenosis and tolerance. However, the mechanism of resistance is poorly understood at the molecular level. Aphid-induced transcriptional changes, including differentially expressed miRNA profiles that correspond to resistance interaction have been reported in melon. The potential regulatory roles of miRNAs in Vat-mediated aphid resistance were further revealed by identifying the specific miRNA degradation targets. A total of 70 miRNA:target pairs, including 28 novel miRNA:target pairs, for the differentially expressed miRNAs were identified: 11 were associated with phytohormone regulation, including six miRNAs that potentially regulate auxin interactions. A model for a redundant regulatory system of miRNA-mediated auxin insensitivity is proposed that incorporates auxin perception, auxin modification and auxin-regulated transcription. Chemically inhibiting the transport inhibitor response-1 (TIR-1) auxin receptor in susceptible melon tissues provides in vivo support for the model of auxin-mediated impacts on A. gossypii resistance.

  7. Induction of soluble and cell wall peroxidases by aphid infestation in barley.

    Science.gov (United States)

    Chaman, M E; Corcuera, L J; Zúñiga, G E; Cardemil, L; Argandoña, V H

    2001-05-01

    Peroxidase enzymes have been found in soluble, ionically bound, and covalently bound forms and have been implicated in several physiological processes in plants. This paper investigates the effect of aphid infestation on soluble and bound-cell wall peroxidase activity and bound-cell wall isoform changes of barley plants. Peroxidase activity was measured in control plants and plants infested with the aphid Schizaphis graminum (Rondani). The activity of soluble peroxidases increased with time of infestation, older plants being more affected than younger ones. The increase in bound-cell wall peroxidase activity as a function of age was higher in infested than in control plants, being higher in ionically bound than in covalently bound peroxidases. When the aphids were removed from plants, the activities of both types of peroxidases decreased to control levels. Isoelectrofocusing analyses of the ionically bound peroxidases showed changes in the isoform pattern. A new isoform was induced by infestation. The activities of all covalently bound isoforms increased after infestation. The physiological implications of these changes are discussed.

  8. CmMYB19 Over-Expression Improves Aphid Tolerance in Chrysanthemum by Promoting Lignin Synthesis

    Science.gov (United States)

    Wang, Yinjie; Sheng, Liping; Zhang, Huanru; Du, Xinping; An, Cong; Xia, Xiaolong; Chen, Fadi; Jiang, Jiafu; Chen, Sumei

    2017-01-01

    The gene encoding the MYB (v-myb avian myeloblastosis vira l oncogene homolog) transcription factor CmMYB19 was isolated from chrysanthemum. It encodes a 200 amino acid protein and belongs to the R2R3-MYB subfamily. CmMYB19 was not transcriptionally activated in yeast, while a transient expression experiment conducted in onion epidermal cells suggested that the CmMYB19 product localized to the nucleus. CmMYB19 transcription was induced by aphid (Macrosiphoniella sanborni) infestation, and the abundance of transcript was higher in the leaf and stem than in the root. The over-expression of CmMYB19 restricted the multiplication of the aphids. A comparison of transcript abundance of the major genes involved in lignin synthesis showed that CmPAL1 (phenylalanine ammonia lyase 1), CmC4H (cinnamate4 hydroxylase), Cm4CL1 (4-hydroxy cinnamoyl CoA ligase 1), CmHCT (hydroxycinnamoyl CoA-shikimate/quinate hydroxycinnamoyl transferase), CmC3H1 (coumarate3 hydroxylase1), CmCCoAOMT1 (caffeoyl CoA O-methyltransferase 1) and CmCCR1 (cinnamyl CoA reductase1) were all upregulated, in agreement with an increase in lignin content in CmMYB19 over-expressing plants. Collectively, the over-expression of CmMYB19 restricted the multiplication of the aphids on the host, mediated by an enhanced accumulation of lignin. PMID:28287502

  9. Transgenerational shifts in reproduction hormesis in green peach aphid exposed to low concentrations of imidacloprid.

    Science.gov (United States)

    Ayyanath, Murali-Mohan; Cutler, G Christopher; Scott-Dupree, Cynthia D; Sibley, Paul K

    2013-01-01

    Hormesis is a biphasic phenomenon that in toxicology is characterized by low-dose stimulation and high-dose inhibition. It has been observed in a wide range of organisms in response to many chemical stressors, including insects exposed to pesticides, with potential repercussions for agriculture and pest management. To address questions related to the nature of the dose-response and potential consequences on biological fitness, we examined transgenerational hormesis in the green peach aphid, Myzus persicae, when exposed to sublethal concentrations of the insecticide imidacloprid. A hormetic response in the form of increased reproduction was consistently observed and a model previously developed to test for hormesis adequately fit some of our data. However, the nature of the dose-response differed within and across generations depending upon the duration and mode of exposure. Decreased reproduction in intermediate generations confirmed that fitness tradeoffs were a consequence of the hormetic response. However, recovery to levels of reproduction equal to that of controls in subsequent generations and significantly greater total reproduction after four generations suggested that biological fitness was increased by exposure to low concentrations of the insecticide, even when insects were continuously exposed to the stressor. This was especially evident in a greenhouse experiment where the instantaneous rate of population increase almost doubled and total aphid production more than quadrupled when aphids were exposed to potato plants systemically treated with low amounts of imidacloprid. Our results show that although fitness tradeoffs do occur with hormetic responses, this does not necessarily compromise overall biological fitness.

  10. Pest trade-offs in technology: reduced damage by caterpillars in Bt cotton benefits aphids.

    Science.gov (United States)

    Hagenbucher, Steffen; Wäckers, Felix L; Wettstein, Felix E; Olson, Dawn M; Ruberson, John R; Romeis, Jörg

    2013-05-07

    The rapid adoption of genetically engineered (GE) plants that express insecticidal Cry proteins derived from Bacillus thuringiensis (Bt) has raised concerns about their potential impact on non-target organisms. This includes the possibility that non-target herbivores develop into pests. Although studies have now reported increased populations of non-target herbivores in Bt cotton, the underlying mechanisms are not fully understood. We propose that lack of herbivore-induced secondary metabolites in Bt cotton represents a mechanism that benefits non-target herbivores. We show that, because of effective suppression of Bt-sensitive lepidopteran herbivores, Bt cotton contains reduced levels of induced terpenoids. We also show that changes in the overall level of these defensive secondary metabolites are associated with improved performance of a Bt-insensitive herbivore, the cotton aphid, under glasshouse conditions. These effects, however, were not as clearly evident under field conditions as aphid populations were not correlated with the amount of terpenoids measured in the plants. Nevertheless, increased aphid numbers were visible in Bt cotton compared with non-Bt cotton on some sampling dates. Identification of this mechanism increases our understanding of how insect-resistant crops impact herbivore communities and helps underpin the sustainable use of GE varieties.

  11. Resistance of wild Solanum accessions to aphids and other potato pests in Quebec field conditions.

    Science.gov (United States)

    Fréchette, B; Bejan, M; Lucas, E; Giordanengo, P; Vincent, C

    2010-01-01

    Two experiments were done to determine the susceptibility of six wild potato accessions to the aphids Macrosiphum euphorbiae (Thomas) (Hemiptera: Aphididae) and Myzus persicae (Sulzer). Densities of aphid colonies were compared between caged Solanum pinnatisectum Dunal (Solanales: Solanaceae), S. polyadenium Greenmam, S. tarijense Hawkes, S. infundibuliforme Philippi, S. oplocense Hawkes, and S. stoloniferum Schlechted and Bouché, and the commercially cultivated potato plant S. tuberosum L. cv. Désirée. Moreover the susceptibility of S. polyadenium and S. tarijense to the Colorado potato beetle Leptinotarsa decemlineata (Say) (Coleoptera: Chrlysomelidae), the potato flea beetle Epitrix cucumeris (Harris), and the potato leafhopper Empoasca fabae (Harris) (Hemiptera: Cicadellidae) was compared to that of S. tuberosum cv. Désirée in the field. Results indicated that S. polyadenium and S. tarijense were more resistant to M. persicae than S. pinnatisectum and the commercially cultivated S. tuberosum cv. Désirée. Solanum polyadenium was more resistant to aphids than S. tarijense in 2004, but not in 2005. Moreover, S. polyadenium and S. tarijense were more resistant than S. tuberosum cv. Désirée to L. decemlineata, E. cucumeris and E. fabae.

  12. Alterations in the nitrogen dynamics of European beech trees infested by the woolly beech aphid

    Science.gov (United States)

    Levia, D. F.; Michalzik, B.

    2012-12-01

    Insects are a major stressor in wooded ecosystems, triggering profound changes in the hydrology, biogeochemistry, and net primary productivity of infested forests. The influence of woolly beech aphids (Phyllaphis fagi L.) on nitrogen cycling via throughfall, stemflow, and litter leachates is not well understood. Employing a combination of field sampling, X-ray photoelectron spectroscopy, and scanning electron microscopy, we examined and compared the alterations and partitioning of nitrogen (particulate, dissolved, organic, inorganic) between control (uninfested) and infested trees. Preliminary results suggest that the amount of nitrogen routed to the soil is much lower in throughfall and stemflow of infested trees than control trees. Preliminary X-ray photoelectron spectroscopy and scanning electron microscopy measurements on the abaxial surface of sample leaves have demonstrated that the surface microbiology and nitrogen chemistry of control, lightly infested, and heavily infested leaves are notably different. These observations suggest that the aphids alter the phyllosphere ecology to such an extent that they trigger nitrogen uptake by microbes on the leaf surface in the presence of easily available carbon from aphid excretions (i.e., honeydew). A better understanding of nitrogen cycling in stressed forests would advance theories of nitrogen cycling.

  13. Comparative analysis of mitochondrial genomes of five aphid species (Hemiptera: Aphididae and phylogenetic implications.

    Directory of Open Access Journals (Sweden)

    Yuan Wang

    Full Text Available Insect mitochondrial genomes (mitogenomes are of great interest in exploring molecular evolution, phylogenetics and population genetics. Only two mitogenomes have been previously released in the insect group Aphididae, which consists of about 5,000 known species including some agricultural, forestry and horticultural pests. Here we report the complete 16,317 bp mitogenome of Cavariella salicicola and two nearly complete mitogenomes of Aphis glycines and Pterocomma pilosum. We also present a first comparative analysis of mitochondrial genomes of aphids. Results showed that aphid mitogenomes share conserved genomic organization, nucleotide and amino acid composition, and codon usage features. All 37 genes usually present in animal mitogenomes were sequenced and annotated. The analysis of gene evolutionary rate revealed the lowest and highest rates for COI and ATP8, respectively. A unique repeat region exclusively in aphid mitogenomes, which included variable numbers of tandem repeats in a lineage-specific manner, was highlighted for the first time. This region may have a function as another origin of replication. Phylogenetic reconstructions based on protein-coding genes and the stem-loop structures of control regions confirmed a sister relationship between Cavariella and pterocommatines. Current evidence suggest that pterocommatines could be formally transferred into Macrosiphini. Our paper also offers methodological instructions for obtaining other Aphididae mitochondrial genomes.

  14. Aphid-willow interactions in a high Arctic ecosystem: responses to raised temperature and goose disturbance.

    Science.gov (United States)

    Gillespie, Mark A K; Jónsdóttir, Ingibjörg S; Hodkinson, Ian D; Cooper, Elisabeth J

    2013-12-01

    Recently, there have been several studies using open top chambers (OTCs) or cloches to examine the response of Arctic plant communities to artificially elevated temperatures. Few, however, have investigated multitrophic systems, or the effects of both temperature and vertebrate grazing treatments on invertebrates. This study investigated trophic interactions between an herbivorous insect (Sitobion calvulum, Aphididae), a woody perennial host plant (Salix polaris) and a selective vertebrate grazer (barnacle geese, Branta leucopsis). In a factorial experiment, the responses of the insect and its host to elevated temperatures using open top chambers (OTCs) and to three levels of goose grazing pressure were assessed over two summer growing seasons (2004 and 2005). OTCs significantly enhanced the leaf phenology of Salix in both years and there was a significant OTC by goose presence interaction in 2004. Salix leaf number was unaffected by treatments in both years, but OTCs increased leaf size and mass in 2005. Salix reproduction and the phenology of flowers were unaffected by both treatments. Aphid densities were increased by OTCs but unaffected by goose presence in both years. While goose presence had little effect on aphid density or host plant phenology in this system, the OTC effects provide interesting insights into the possibility of phenological synchrony disruption. The advanced phenology of Salix effectively lengthens the growing season for the plant, but despite a close association with leaf maturity, the population dynamics of the aphid appeared to lack a similar phenological response, except for the increased population observed.

  15. Tests for host-associated fitness trade-offs in the milkweed-oleander aphid.

    Science.gov (United States)

    Groeters, Francis R

    1993-03-01

    The milkweed-oleander aphid, Aphis nerii (Boyer de Fonscolombe) (Homoptera: Aphididae), feeds on different milkweed species in northern California than in Puerto Rico. The hosts vary, primarily between regions, for both identity and quantity of cardenolides that the aphid sequesters for its own defense. In tests for hostassociated fitness trade-offs only one case was found in which host plant and fitness corresponded, but the effect was not significant. However, power to detect fitness trade-offs was limited and the possibility of considerable differences in fitness on a particular host for aphids from different hosts cannot be excluded. On Californian host species, among which migration is common, generalized host use could result from selection for general-purpose genotypes. However, this explanation cannot apply to generalized host use of Californian and Puerto Rican milkweeds because the regions are isolated by distance. A cardenolide sequestration mechanism that is free of substantial energy costs could provide the basis for fitness homeostasis on variable host plants that makes trade-offs unlikely even on hosts from different regions.

  16. Nitrogen deficiency in barley (Hordeum vulgare) seedlings induces molecular and metabolic adjustments that trigger aphid resistance.

    Science.gov (United States)

    Comadira, Gloria; Rasool, Brwa; Karpinska, Barbara; Morris, Jenny; Verrall, Susan R; Hedley, Peter E; Foyer, Christine H; Hancock, Robert D

    2015-06-01

    Agricultural nitrous oxide (N2O) pollution resulting from the use of synthetic fertilizers represents a significant contribution to anthropogenic greenhouse gas emissions, providing a rationale for reduced use of nitrogen (N) fertilizers. Nitrogen limitation results in extensive systems rebalancing that remodels metabolism and defence processes. To analyse the regulation underpinning these responses, barley (Horedeum vulgare) seedlings were grown for 7 d under N-deficient conditions until net photosynthesis was 50% lower than in N-replete controls. Although shoot growth was decreased there was no evidence for the induction of oxidative stress despite lower total concentrations of N-containing antioxidants. Nitrogen-deficient barley leaves were rich in amino acids, sugars and tricarboxylic acid cycle intermediates. In contrast to N-replete leaves one-day-old nymphs of the green peach aphid (Myzus persicae) failed to reach adulthood when transferred to N-deficient barley leaves. Transcripts encoding cell, sugar and nutrient signalling, protein degradation and secondary metabolism were over-represented in N-deficient leaves while those associated with hormone metabolism were similar under both nutrient regimes with the exception of mRNAs encoding proteins involved in auxin metabolism and responses. Significant similarities were observed between the N-limited barley leaf transcriptome and that of aphid-infested Arabidopsis leaves. These findings not only highlight significant similarities between biotic and abiotic stress signalling cascades but also identify potential targets for increasing aphid resistance with implications for the development of sustainable agriculture.

  17. Erwinia iniecta sp. nov., isolated from Russian wheat aphid (Diuraphis noxia).

    Science.gov (United States)

    Campillo, Tony; Luna, Emily; Portier, Perrine; Fischer-Le Saux, Marion; Lapitan, Nora; Tisserat, Ned A; Leach, Jan E

    2015-10-01

    Short, Gram-negative-staining, rod-shaped bacteria were isolated from crushed bodies of Russian wheat aphid [Diuraphis noxia (Kurdjumov)] and artificial diets after Russian wheat aphid feeding. Based on multilocus sequence analysis involving the 16S rRNA, atpD, infB, gyrB and rpoB genes, these bacterial isolates constitute a novel clade in the genus Erwinia, and were most closely related to Erwinia toletana. Representative distinct strains within this clade were used for comparisons with related species of Erwinia. Phenotypic comparisons using four distinct strains and average nucleotide identity (ANI) measurements using two distinct draft genomes revealed that these strains form a novel species within the genus Erwinia. The name Erwinia iniecta sp. nov. is proposed, and strain B120T ( = CFBP 8182T = NCCB 100485T) was designated the type strain. Erwinia iniecta sp. nov. was not pathogenic to plants. However, virulence to the Russian wheat aphid was observed.

  18. Polymorphisms in salivary-gland transcripts of Russian wheat aphid biotypes 1 and 2

    Institute of Scientific and Technical Information of China (English)

    Feng Cui; C.Michael Smith; John Reese; Owain Edwards; Gerald Reeck

    2012-01-01

    The Russian wheat aphid (RWA),Diuraphis noxia (Mordvilko) (Homoptera:Aphididae),is a major pest of small grains.As with plant-feeding aphids in general,the interaction between RWA and host plants is governed,on the insect side,by proteins and enzymes in saliva.In this work,we examined sequence variations in transcripts encoding proteins and enzymes of RWA salivary glands.We conducted reverse transcription - polymerase chain reaction in RWA biotypes 1 and 2 using primers derived from pea aphid orthoiogs,and cloned regions of 17 putative salivary gland transcripts.For four of the transcripts,we observed no difference in sequences between the two biotypes.For the other 13 transcripts,for example,the transcripts encoding sucrase,trehalase and protein C002,large amount of variations,both within each biotype and between the two biotypes,were observed.Usually the two biotypes shared only one variant,which was typically the most common variant in both biotypes.Most of the transcripts had more non-synonymous than synonymous codon changes among their variants.Our results offer possible molecular markers for distinguishing the two biotypes and insights into their evolution.

  19. Zinc and cadmium accumulation in cabbage aphid(Brevicoryne brassicae)host plants and developmental instability

    Institute of Scientific and Technical Information of China (English)

    Gazi G(o)rür

    2009-01-01

    Developmental instability in morphological characters can occur during individual development due to various environmental stresses.Fluctuating asymmetry (FA)is often used as a measurement of developmental instability.but within-environment variation(cve)is also considered an indicator of developmental instability.Cabbage aphid nated cabbage and radish plants.Developmental instability indicators were measured and their relations with fitness were explored.Results revealed that cabbage aphids exposed to Cd and Zn displayed considerable developmental instability,particularly fluctuating asymmetry.Differences in developmental instability between the two metals were also detected,as well as differences between the two developmental instability measurements.For almost all measured traits.FA was greater on Cd-and Zn-contaminated compared to non-contaminated host plants.In contrast.CV of some traits was greater on non-contami-nated host plants,yet for Otller traits CV Was greater on contaminated host plants.There were also non-significant inverse relationships between FA and fitness of cabbage aphid populations.Due to weak correlations between FA and different patterns of two developmental instability measurements,this study does not support the hypothesis that developmental instability is a useful bioindicator of environmental quality.

  20. The influence of rate and time of nitrate supply on nitrogen fixation and yield in pea (Pisum sativum L.)

    DEFF Research Database (Denmark)

    Jensen, Erik Steen

    1986-01-01

    pea, by the lowest rate of nitrate at this application time. The pea very efficiently took up and assimilated the nitrate N supplied. The average fertilizer N recovery was 82%. The later the N was supplied the more efficiently it was recovered. When nitrate was supplied at the flat pod growth stage 88......The influence of nitrate N supply on dry matter production, N content and symbiotic nitrogen fixation in soil-grown pea (Pisum sativum L.) was studied in a pot experiment by means of15N fertilizer dilution. In pea receiving no fertilizer N symbiotic nitrogen fixation, soil and seed-borne N...... contributed with 82, 13 and 5% of total plant N, respectively. The supply of low rates of nitrate fertilizer at sowing (“starter N”) increased the vegetative dry matter production, but not the seed yield significantly. Nitrogen fixation was not significantly decreased by the lower rates of nitrate but higher...

  1. Relationship of (/sup 3/H)GA/sub 9/ metabolism to photoperiod-induced flowering in pisum sativum L

    Energy Technology Data Exchange (ETDEWEB)

    Proebsting, W.M.; Heftmann, E.

    1980-07-01

    The late flowering line of pea designated G is an obligate long day plant with respect to flowering. (/sup 3/H)GA/sub 9/ metabolism by leaves of G was studied. In short days (SD), (/sup 3/H)GA/sub 9/ was converted to a series of polar compounds. The synthesis of these polar compounds was blocked by 1 long day (D). One LD also induced flowering. Reproductive G plants which reverted to the vegetative state regained the ability to synthesize polar gibberellins from (/sup 3/H)GA/sub 9/. These observations support the hypothesis that flowering in Pisum is inhibited by a polar gibberellin produced in SD. LD prevent the synthesis of polar gibberellins, permitting flowering to take place.

  2. Computational Modelling of Pisum Sativum L. Superoxide Dismutase and Prediction of Mutational Variations through in silico Methods

    Directory of Open Access Journals (Sweden)

    Nathan Vinod Kumar

    2014-06-01

    Full Text Available Superoxide dismutase (SOD is one of the major enzymes expressed in the oxidative stress pathway in plants. Its expression is also evident in other taxonomic group in oxidative reactions. Pisum sativum a common plant is being studied in the present work where SOD is characterized using computational tools. SOD sequence of P. sativum [CAA42737.1] Ala and Leu rich protein with alkaline pI value was used as query sequence and used to obtain nine similar sequences through BLASTp. Phylogenetic tree was constructed using MEGA 5.0 based on neighbour joining method. Physiochemical parameters and amino acid composition was studied and compared with query sequences and other similar sequences. Secondary structures were predicted to understand the dominant components. Homology modeling of P. sativum SOD was done using SWISS MODEL and quality was evaluated using standard methods. 27 active sites were detected in SOD predicted model which were Lys rich.

  3. The conformational stability and biophysical properties of the eukaryotic thioredoxins of Pisum sativum are not family-conserved.

    Directory of Open Access Journals (Sweden)

    David Aguado-Llera

    Full Text Available Thioredoxins (TRXs are ubiquitous proteins involved in redox processes. About forty genes encode TRX or TRX-related proteins in plants, grouped in different families according to their subcellular localization. For instance, the h-type TRXs are located in cytoplasm or mitochondria, whereas f-type TRXs have a plastidial origin, although both types of proteins have an eukaryotic origin as opposed to other TRXs. Herein, we study the conformational and the biophysical features of TRXh1, TRXh2 and TRXf from Pisum sativum. The modelled structures of the three proteins show the well-known TRX fold. While sharing similar pH-denaturations features, the chemical and thermal stabilities are different, being PsTRXh1 (Pisum sativum thioredoxin h1 the most stable isoform; moreover, the three proteins follow a three-state denaturation model, during the chemical-denaturations. These differences in the thermal- and chemical-denaturations result from changes, in a broad sense, of the several ASAs (accessible surface areas of the proteins. Thus, although a strong relationship can be found between the primary amino acid sequence and the structure among TRXs, that between the residue sequence and the conformational stability and biophysical properties is not. We discuss how these differences in the biophysical properties of TRXs determine their unique functions in pea, and we show how residues involved in the biophysical features described (pH-titrations, dimerizations and chemical-denaturations belong to regions involved in interaction with other proteins. Our results suggest that the sequence demands of protein-protein function are relatively rigid, with different protein-binding pockets (some in common for each of the three proteins, but the demands of structure and conformational stability per se (as long as there is a maintained core, are less so.

  4. Measurements of chlorophyll fluorescence as an auxiliary method in estimating susceptibility of cultivated hazel (Corylus L. for filbert aphid (Myzocallis coryli goetze

    Directory of Open Access Journals (Sweden)

    Magdalena Gantner

    2012-12-01

    Full Text Available The influence of aphid feeding on chlorophyll a fluorescence in the leaves of four cultivated hazel cultivars, with different levels of resistance to filbert aphid (Myzocallis coryli Goetze, was studied. The maximum effect of photosystem reaction measured on dark-adapted hazel leaves (Fv/Fm parameter and maximum efficiency of photon energy PAR conversion to chemical energy in light conditions (Y parameter were estimated twice, in the leaves of four hazel cultivars with different levels of resistance to filbert aphid, using a fluorometer PAM- 2000 by Walz GmbH - Germany. The analysis of changes of these parameters showed that aphid feeding caused a reaction in all tested cultivars. The most visible reduction of the Fv/Fm and Y values as a result of aphid feeding was observed in the cultivars 'Cud z Bollwiller' and 'Olbrzymi z Halle', numerously colonized by aphids. A smaller number of aphids found on the leaves of more resistant cultivars - 'Kataloński' and 'Lamberta Biały', caused a weaker response of plants and a smaller decline in the value of this parameter. 'Cud z Bollwiller' cultivar showed higher tolerance than other tested cultivars to stress caused by the feeding of sucking insects. The Fv/Fm and Y parameters can be regarded as reliable indexes useful in diagnosing susceptibility of hazel cultivars to aphids, helpful in determining, for example, harmfulness thresholds.

  5. Molecular evolution of aphids and their primary ( Buchnera sp.) and secondary endosymbionts: implications for the role of symbiosis in insect evolution.

    NARCIS (Netherlands)

    Sabater-Munoz, B.; Ham, van R.C.H.J.; Martinez-Torres, D.; Silva, F.J.; Latorre, A.; Moya, A.

    2001-01-01

    Aphids maintain an obligate, endosymbiotic association with Buchnera sp., a bacterium closely related to Escherichia coli. Bacteria are housed in specialized cells of organ-like structures called bacteriomes in the hemocoel of the aphid and are maternally transmitted. Phylogenetic studies have shown

  6. Temperature dependent functional response of Diaeretiella rapae (Hymenoptera: Aphidiidae) to the cabbage aphid, Brevicoryne brassicae (Hemiptera: Aphididae)

    DEFF Research Database (Denmark)

    Moayeri, Hamid R. S.; Madadi, Hossein; Pouraskari, Hossein;

    2013-01-01

    Diaeretiella rapae MacIntosh (Hymenoptera: Aphidiidae) is one of the most common and successful parasitoids of the cabbage aphid. The functional response of D. rapae towards cabbage aphids was examined in laboratory studies at three constant temperatures, 17°C, 25°C and 30°C. D. rapae exhibited...

  7. Interspecific Associations between Cycloneda sanguinea and Two Aphid Species (Aphis gossypii and Hyadaphis foeniculi) in Sole-Crop and Fennel-Cotton Intercropping Systems

    OpenAIRE

    Francisco S Fernandes; Ramalho, Francisco S.; Malaquias,José B.; Godoy, Wesley A. C.; Santos, Bárbara Davis B.

    2015-01-01

    Aphids cause significant damage to crop plants. Studies regarding predator-prey relationships in fennel (Foeniculum vulgare Mill.) and cotton (Gossypium hirsutum L.) crops are important for understanding essential ecological interactions in the context of intercropping and for establishing pest management programs for aphids. This study evaluated the association among Hyadaphis foeniculi (Passerini) (Hemiptera: Aphididae), Aphis gossypii Glover (Hemiptera: Aphididae) and Cycloneda sanguinea (...

  8. Relationships between salicylic acid content, phenylalanine ammonia-lyase (PAL) activity, and resistance of barley to aphid infestation.

    Science.gov (United States)

    Chaman, Mercedes E; Copaja, Sylvia V; Argandoña, Victor H

    2003-04-09

    It has been suggested that salicylic acid (SA) is a signal in acquired resistance to pathogens in several plants. Also, it has been suggested that infestation of plants causes an increase in the activity of phenylalanine ammonia-lyase (PAL), a key phenolic biosynthesis enzyme. The purpose of this work was to investigate whether the induction of SA and PAL activity is related to the susceptibility of barley to aphid infestation. The induction of free and conjugated SA in two barley cultivars that differ in susceptibility to aphids was analyzed. Analyses of several physiological parameters showed that cv. UNA-80 was more susceptible to the aphid Schizaphis graminum than cv. LM-109. Salicylic acid was not detected in noninfested plants. Levels of free and conjugated SA in cv. LM-109 and of conjugated SA in cv. UNA-80 increased with aphid infestation, whereas the levels of free SA in cv. UNA-80 remained high under all infestation degrees. Maximum values reached in both cultivars were not significantly different. With respect to PAL activity, cv. LM-109 showed a significantly higher specific activity than cv. UNA-80, the more susceptible cultivar. The relationship between the susceptibility of a plant to aphid and SA induction and PAL activity is discussed.

  9. Migration and population genetics of the grain aphid Macrosiphum miscanti (Takahashi) in relation to the geographic distance and gene flow

    Institute of Scientific and Technical Information of China (English)

    GUO Wei; SHEN Zuorui; LI Zhihong; GAO Lingwang

    2005-01-01

    The population genetics of the grain aphid Macrosiphum miscanti (Takahashi) is analyzed by microsatellite markers.Samples collected from 15 locations in China have been examined at 5 polymorphic microsatellite loci. Overall, genetic diversity displays a relation between the migration and gene flow in the grain aphid: a free and frequent gene flow is found in the eastern populations, and gene isolation occurs in the two western populations, especially Datong population and Guiyang population. The natural barriers may present an insurmountable obstacle preventing gene flow and aphid migration. However, a spatial genetic differentiation between populations is correlated with their geographical separation, indicating the geographic differentiation may play an important role in shaping the genetic structure of M. miscanti populations. In addition, most populations of grain aphids are out of Hardy-Weinberg equilibrium and there is heterozygote deficit. Based on F statistics, the average genetic differentiation among different geographical populations is relatively low. It seems that the long distance migration of the grain aphid may enhance gene flow and decrease genetic differentiation among different populations.

  10. Screening low fire blight susceptible Crataegus species for host suitability to hawthorn leaf-curling aphids (Dysaphis spp.).

    Science.gov (United States)

    Bribosia, E; Bylemans, D; Van Impe, G; Migon, M

    2002-01-01

    The group of hawthorn leaf-curling aphids (Dysaphis spp.) hosted by the common hawthorn Crataegus monogyna Jacq. may play an important role in the biological control of the rosy apple aphid, Dysaphis plantaginea (Passerini), by increasing reproduction opportunities for the indigenous hymenopteran parasitoid Ephedrus persicae Froggatt. Unfortunately, most fruitgrowers hesitate to introduce the common hawthorn in their orchards because they fear fire blight infections which may be transmitted by this highly susceptible hawthron species. This potential hazard led us to investigate the suitability to leaf-curling aphids of alternative Crataegus species. As representative for these closely-related aphids, the species Dysaphis apiifolia petroselini (Börner) was used in the trials. Ten Crataegus species characterized by their very low susceptibility to fire blight were examined from two angles. Firstly, aphid sexuals were introduced in autumn onto the different species to verify whether egg laying could take place. Secondly, the development of fundatrices and gall formation were followed the next spring. Although eggs and mature fundatrices could be obtained on almost all species, no fundatrice-hosting galls were recorded in spring. The possible causes of these negative results with respect to the geographical origin of the particular Crataegus species involved in this work are discussed.

  11. Genetic structure of the aphid, Chaetosiphon fragaefolii, and its role as a vector of the Strawberry Yellow Edge Virus to a native strawberry, Fragaria chiloensis in Chile.

    Science.gov (United States)

    Lavandero, Blas; Rojas, Pamela; Ramirez, Claudio C; Salazar, Marcela; Caligari, Peter D S

    2012-01-01

    The monoecious anholocyclical aphid, Chaetosiphon fragaefolii (Cockerell) (Homoptera: Aphididae), was collected on a native strawberry, Fragaria chiloensis (L.) Duchesne (Rosales: Rosaceae) from different sites in Chile. The presence of this aphid was recorded during two consecutive years. F. chiloensis plants were collected from seven natural and cultivated growing areas in central and southern Chile. Aphids were genotyped by cross-species amplification of four microsatellite loci from other aphid species. In addition, the aphid borne virus Strawberry mild yellow edge virus was confirmed in F. chiloensis plants by double-antibody sandwich ELISA and RT-PCR. Genetic variability and structure of the aphid populations was assessed from the geo-referenced individuals through AMOVA and a Bayesian assignment test. The presence of C. fragaefolii, during the two-year study was detected in only four of the seven sites (Curepto, Contulmo, Chilián and Cucao). Genetic variation among these populations reached 19% of the total variance. When assigning the individuals to groups, these were separated in three genetic clusters geographically disjunct. Of the seven sampled sites, six were positive for the virus by RT-PCR, and five by double-antibody sandwich ELISA . The incidence of the virus ranged from 0-100%. Presence of the virus corresponded with the presence of the aphid in all but two sites (Chilian and Vilches). The greatest incidence of Strawberry mild yellow edge virus was related to the abundance of aphids. On the other hand, sequences of the coat protein gene of the different virus samples did not show correspondence with either the genetic groups of the aphids or the sampling sites. The genetic structure of aphids could suggest that dispersal is mainly through human activities, and the spread to natural areas has not yet occurred on a great scale.

  12. Exposure to bacterial signals does not alter pea aphids' survival upon a second challenge or investment in production of winged offspring.

    Directory of Open Access Journals (Sweden)

    Bas ter Braak

    Full Text Available Pea aphids have an obligate nutritional symbiosis with the bacteria Buchneraaphidicola and frequently also harbor one or more facultative symbionts. Aphids are also susceptible to bacterial pathogen infections, and it has been suggested that aphids have a limited immune response towards such pathogen infections compared to other, more well-studied insects. However, aphids do possess at least some of the genes known to be involved in bacterial immune responses in other insects, and immune-competent hemocytes. One possibility is that immune priming with microbial elicitors could stimulate immune protection against subsequent bacterial infections, as has been observed in several other insect systems. To address this hypothesis we challenged aphids with bacterial immune elicitors twenty-four hours prior to live bacterial pathogen infections and then compared their survival rates to aphids that were not pre-exposed to bacterial signals. Using two aphid genotypes, we found no evidence for immune protection conferred by immune priming during infections with either Serratia marcescens or with Escherichia coli. Immune priming was not altered by the presence of facultative, beneficial symbionts in the aphids. In the absence of inducible immune protection, aphids may allocate energy towards other defense traits, including production of offspring with wings that could escape deteriorating conditions. To test this, we monitored the ratio of winged to unwinged offspring produced by adult mothers of a single clone that had been exposed to bacterial immune elicitors, to live E. coli infections or to no challenge. We found no correlation between immune challenge and winged offspring production, suggesting that this mechanism of defense, which functions upon exposure to fungal pathogens, is not central to aphid responses to bacterial infections.

  13. Draft Genome Sequence of the Plant Growth-Promoting Rhizobacterium Pseudomonas fluorescens Strain CREA-C16 Isolated from Pea (Pisum sativum L.) Rhizosphere

    Science.gov (United States)

    Sorrentino, Roberto; Scotti, Riccardo; Salzano, Melania; Aurilia, Vincenzo

    2017-01-01

    ABSTRACT Herein, we report the draft genome sequence of Pseudomonas fluorescens strain CREA-C16, a plant growth-promoting rhizobacterium that was isolated from the rhizosphere of Pisum sativum L. plants. The genome sequence is ~6 Mb in size, with a G+C content of 60.1%, and includes 4,457 candidate protein-encoding genes. PMID:28126933

  14. The effects of monitoring the abundance and species composition of aphids as virus vectors on seed potato production in Serbia

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    Drago Milošević

    2014-03-01

    Full Text Available Aphids are the most important vectors of potato viruses during the crop’s growing season. The most widespread and damaging viruses, the potato virus Y and potato leaf roll virus, are transmitted by aphids in non-persistent and persistent manner, respectively. The two viruses cause the greatest concern of potato producers and a great constraint to seed potato production in Serbia, the region and across the world. Potato virus Y is particularly harmful, given its distribution and spreading rate. Seed potato production systems under well-managed conditions involve a series of virus control measures, including the monitoring of outbreaks of winged aphids, their abundance and species composition, in order to forecast virosis, i.e. potential plant and tuber infection periods. Monitoring the aphid vectors of potato viruses enables determination of optimum dates for haulm destruction when higher than normal numbers of winged aphids as vectors of economically harmful diseases have been observed. Haulm destruction in a potato crop reduces the risk of plant infection and virus translocation from the aboveground parts to tubers, thus keeping the proportion of infected tubers within tolerance limits allowed for certain categories of seed potatoes. This practice has positive effects if used in combination with other viral disease control measures; otherwise, it becomes ineffective. This paper provides an integral analysis of the effects and role of monitoring outbreaks of aphids, their abundance and species composition in timing haulm growth termination to prevent plant infection, virus translocation and tuber infestation in potato crops in Serbia and the wider region.

  15. Assessment of Sublethal and Transgenerational Effects of Pirimicarb on the Wheat Aphids Rhopalosiphum padi and Sitobion avenae

    Science.gov (United States)

    Desneux, Nicolas; Han, Peng; Gao, Xiwu

    2015-01-01

    The wheat aphids, Rhopalosiphum padi (Linnaeus) and Sitobion avenae (Fabricius), are key pests on wheat crops worldwide. Management practices rely primarily on insecticides. The pirimicarb (carbamate) is used extensively as an effective insecticide to control these two aphids. In addition to the mortality caused by pirimicarb, various sublethal effects may occur in aphids when exposed to low lethal or sublethal doses. Understanding the general effect of pirimicarb on aphids could help increasing rational use of this insecticide. Under laboratory conditions, we assessed the sublethal effects of a low lethal concentration of pirimicarb (LC25) on biological traits and acetylcholinesterase (AChE) activity of R. padi and S. avenae. Both direct and transgenerational effects, i.e. on parent and the F1 generations were assessed, respectively. We found that R. padi and S. avenae responded differentially to the LC25 of pirimicarb. The parent generation of R. padi showed a 39% decrease in fecundity and multiple transgenerational effects were observed in the F1 generation; overall juvenile development, reproductive period, adult longevity and lifespan were longer than those of the control group. By contrast, LC25 of pirimicarb showed almost no effects on S. avenae biological traits in both the parent and F1 generations; only the pre-reproductive duration was reduced in F1 generations. Demographic parameter estimates (e.g. rm) showed similar trend, i.e. significant negative effect on R. padi population growth and no effect on S. avenae. However, AChE activity decreased in both R. padi and S. avenae treated by the LC25 of pirimicarb. We demonstrated sublethal and transgenerational effects of pirimicarb in the two wheat aphid species; it hinted at the importance of considering sublethal effects (including hormesis) of pirimicarb for optimizing Integrated Pest Management (IPM) of wheat aphids. PMID:26121265

  16. Cloning of Partial Sodium Channel Gene From Strains of Fenvalerate-Resistant and Susceptible Cotton Aphid(Aphis gossypii Glover)

    Institute of Scientific and Technical Information of China (English)

    SUN Lu-juan; GAO Xi-wu; ZHENG Bing-zong

    2003-01-01

    The strain of fenvalerate-resistant cotton aphids was selected using fenvalerate insecticide in the laboratory, the resistance factor of the strain was 199.54. Three degenerate primers were designed and used to perform PCR amplification. A cDNA encoding partial sodium channel gene was cloned from the fenvalerate-resistant and -susceptible strains. There were two nucleotide acid differences between fenvalerate-resistant strain and -susceptible strain, resulting in an amino acid mutation, Met→Leu. It is predicted that the mutation is related to the cotton aphid resistance to fenvalerate.

  17. Transgenerational shifts in reproduction hormesis in green peach aphid exposed to low concentrations of imidacloprid.

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    Murali-Mohan Ayyanath

    Full Text Available Hormesis is a biphasic phenomenon that in toxicology is characterized by low-dose stimulation and high-dose inhibition. It has been observed in a wide range of organisms in response to many chemical stressors, including insects exposed to pesticides, with potential repercussions for agriculture and pest management. To address questions related to the nature of the dose-response and potential consequences on biological fitness, we examined transgenerational hormesis in the green peach aphid, Myzus persicae, when exposed to sublethal concentrations of the insecticide imidacloprid. A hormetic response in the form of increased reproduction was consistently observed and a model previously developed to test for hormesis adequately fit some of our data. However, the nature of the dose-response differed within and across generations depending upon the duration and mode of exposure. Decreased reproduction in intermediate generations confirmed that fitness tradeoffs were a consequence of the hormetic response. However, recovery to levels of reproduction equal to that of controls in subsequent generations and significantly greater total reproduction after four generations suggested that biological fitness was increased by exposure to low concentrations of the insecticide, even when insects were continuously exposed to the stressor. This was especially evident in a greenhouse experiment where the instantaneous rate of population increase almost doubled and total aphid production more than quadrupled when aphids were exposed to potato plants systemically treated with low amounts of imidacloprid. Our results show that although fitness tradeoffs do occur with hormetic responses, this does not necessarily compromise overall biological fitness.

  18. Dynamics of nonpersistent aphid-borne viruses in lettuce crops covered with UV-absorbing nets.

    Science.gov (United States)

    Legarrea, S; Betancourt, M; Plaza, M; Fraile, A; García-Arenal, F; Fereres, A

    2012-04-01

    Aphid-transmitted viruses frequently cause severe epidemics in lettuce grown under Mediterranean climates. Spatio-temporal dynamics of aphid-transmitted viruses and its vector were studied on lettuce (Lactuca sativa L.) grown under tunnels covered by two types of nets: a commercial UV-absorbing net (Bionet) and a Standard net. A group of plants infected by Cucumber mosaic virus (CMV, family Bromoviridae, genus Cucumovirus) and Lettuce mosaic virus (LMV, family Potyviridae, genus Potyvirus) was transplanted in each plot. The same virus-infected source plants were artificially infested by the aphid Macrosiphum euphorbiae (Thomas). Secondary spread of insects was weekly monitored and plants were sampled for the detection of viruses every two weeks. In 2008, the infection rate of both CMV and LMV were lower under the Bionet than under the Standard cover, probably due to the lower population density and lower dispersal rate achieved by M. euphorbiae. However, during spring of 2009, significant differences in the rate of infection between the two covers were only found for LMV six weeks after transplant. The spatial distribution of the viruses analysed by SADIE methodology was "at random", and it was not associated to the spatial pattern of the vector. The results obtained are discussed analyzing the wide range of interactions that occurred among UV-radiation, host plant, viruses, insect vector and environmental conditions. Our results show that UV-absorbing nets can be recommended as a component of an integrated disease management program to reduce secondary spread of lettuce viruses, although not as a control measure on its own.

  19. Effects of elevated CO2 and plant genotype on interactions among cotton, aphids and parasitoids

    Institute of Scientific and Technical Information of China (English)

    Yu-Cheng Sun; Li Feng; Feng Gao; Feng Ge

    2011-01-01

    Effects of CO2 level (ambient vs.elevated) on the interactions among three cotton (Gossypium hirsutum) genotypes,the cotton aphid (Aphis gossypii Glover),and its hymenoptera parasitoid (Lysiphlebiajaponica Ashrnead) were quantified.It was hypothesized that aphid-parasitoid interactions in crop systems may be altered by elevated CO2,and that the degree of change is influenced by plant genotype.The cotton genotypes had high (M9101),medium (HZ401) and low (ZMS 13) gossypol contents,and the response to elevated CO2 was genotype-specific.Elevated CO2 increased the ratio of total non-structural carbohydrates to nitrogen (TNC:N) in the high-gossypol genotype and the mediumgossypol genotype.For all three genotypes,elevated CO2 had no effect on concentrations of gossypol and condensed tannins.A.gossypii fitness declined when aphids were reared on the high-gossypol genotype versus the low-gossypol genotype under elevated CO2.Furthermore,elevated CO2 decreased the developmental time of L.japonica associated with the high-gossypol genotype and the low-gossypol genotype,but did not affect parasitism or emergence rates.Our study suggests that the abundance of A.gossypii on cotton will not be directly affected by increases in atmospheric CO2.We speculate that A.gossypii may diminish in pest status in elevated CO2 and high-gossypol genotype environments because of reduced fitness to the high-gossypol genotype and shorter developmental time of L.japonica.

  20. Feeding of Whitefly on Tobacco Decreases Aphid Performance via Increased Salicylate Signaling.

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    Haipeng Zhao

    Full Text Available The feeding of Bemisia tabaci nymphs trigger the SA pathway in some plant species. A previous study showed that B. tabaci nymphs induced defense against aphids (Myzus persicae in tobacco. However, the mechanism underlying this defense response is not well understood.Here, the effect of activating the SA signaling pathway in tobacco plants through B. tabaci nymph infestation on subsequent M. persicae colonization is investigated. Performance assays showed that B. tabaci nymphs pre-infestation significantly reduced M. persicae survival and fecundity systemically in wild-type (WT but not salicylate-deficient (NahG plants compared with respective control. However, pre-infestation had no obvious local effects on subsequent M. persicae in either WT or NahG tobacco. SA quantification results indicated that the highest accumulation of SA was induced by B. tabaci nymphs in WT plants after 15 days of infestation. These levels were 8.45- and 6.14-fold higher in the local and systemic leaves, respectively, than in controls. Meanwhile, no significant changes of SA levels were detected in NahG plants. Further, biochemical analysis of defense enzymes polyphenol oxidase (PPO, peroxidase (POD, β-1,3-glucanase, and chitinase demonstrated that B. tabaci nymph infestation increased these enzymes' activity locally and systemically in WT plants, and there was more chitinase and β-1, 3-glucanase activity systemically than locally, which was opposite to the changing trends of PPO. However, B. tabaci nymph infestation caused no obvious increase in enzyme activity in any NahG plants except POD.In conclusion, these results underscore the important role that induction of the SA signaling pathway by B. tabaci nymphs plays in defeating aphids. It also indicates that the activity of β-1, 3-glucanase and chitinase may be positively correlated with resistance to aphids.

  1. Testing semiochemicals from aphid, plant and conspecific:attraction of Harmonia axyridis

    Institute of Scientific and Technical Information of China (English)

    Pascal D.Leroy; Thomas Schillings; Julien Farmakidis; Stéphanie Heuskin; Georges Lognay; Francois J.Verheggen; Yves Brostaux; Eric Haubruge; Frédéric Francis

    2012-01-01

    Abstract Harmonia axyridis Pallas (Coleoptera:Coccinellidae) is an invasive specie affecting the dynamics and composition of several guilds.Nowadays,no biological control method is available to reduce the populations of this harmful coccinellid.Attractants and semiochemicals seem to be the best alternative but only few studies have tested the impact of semiochemicals on this Asian lady beetle.In this work,through windtunnel expcriments,semiochemicals from aphids (Z,E-nepetalactone,[E]-β-farnesene,α-pinene and β-pinene),from coccinellids ([-]-β-caryophyllene) and from the nettle Urtica dioica L.were evaluated as potential attractants.The nettle volatile compounds ([Z]-3-hexenol and [E]-2-hexenal) were extracted using a Clevenger Apparatus and identified by headspace gas chromatography-mass spectroscopy.In the wind-tunnel experiments,the main components of the aphid alarm pheromone as well as a component of the aphid sexual pheromone strongly attracted both sexes of the Asian lady beetle while (-)-β-caryophyllene only attracted few individuals and had no impact on the males.The nettle extract as well as the (Z)-3-hexenol oriented both males and females to the odor source.The (E)-2-hexenal was shown to have no effect on females even if this green leaf volatile attracted males.Because Z,E-nepetalactone was identified as the most efficient attractant in the wind-tunnel experiments,this volatile was also tested in a potato field where H.axyridis has been showed to respond to this semiochemical.This study highlighted that Z,E-nepetalactone orientated the Asian lady beetle H.axyridis under natural conditions,indicating that this volatile compound could certainly help for an efficient biological control approach against this invasive specie.

  2. Ultrastructural and cytochemical changes in Pelargonium leaves due to aphid (Acyrthosiphon pelargonii (Kalt. infestation

    Directory of Open Access Journals (Sweden)

    Joanna Ślusarczyk

    2012-12-01

    Full Text Available Infestation of aphid Acyrthosiphon pelargonii (Kalt. caused increased deposition of phenolic compounds in the leaves of Pelargonium sp. Most deposits were located in the vacuole and in the area between the plasma membrane and cell wall, as well as some in the intercellular spaces. In cytoplasm damages were observed involving tonoplast and numerous vesicle deposits in the vicinity of the plasma membrane. Endoplasmic reticulum and myelin structures increased in number, as well as mitochondria whose cristae were longer and larger. Thus, we observed both the increase of organelle activity in such cells and the segregation of damaged areas in the form of membrane degradation.

  3. Barcoding of aphids (Hemiptera, Aphididae and Adelgidae): proper usage of the global data set.

    Science.gov (United States)

    Rakauskas, Rimantas; Bašilova, Jekaterina

    2013-01-01

    Basics of DNA barcoding suppose the creation and operation of an extensive library based on reliably (including possibility for validation) identified specimens. Therefore, information concerning morphological identification of the individual samples used for DNA barcoding, for example, identification keys and descriptions used, must be clearly explained. In addition, the maximum available data set of sequences must be used. Access to currently private data appears to be of special interest, especially when such possibility is provided by the database regulations, because it encourages the cooperation of research and saves both time and resources. The cryptic aphid species complexes Aphis oenotherae-holoenotherae and A. pomi-spiraecola are used to illustrate the above statements.

  4. How accurate is the phenotype? – An analysis of developmental noise in a cotton aphid clone

    Directory of Open Access Journals (Sweden)

    Babbitt Gregory A

    2008-02-01

    Full Text Available Abstract Background The accuracy by which phenotype can be reproduced by genotype potentially is important in determining the stability, environmental sensitivity, and evolvability of morphology and other phenotypic traits. Because two sides of an individual represent independent development of the phenotype under identical genetic and environmental conditions, average body asymmetry (or "fluctuating asymmetry" can estimate the developmental instability of the population. The component of developmental instability not explained by intrapopulational differences in gene or environment (or their interaction can be further defined as internal developmental noise. Surprisingly, developmental noise remains largely unexplored despite its potential influence on our interpretations of developmental stability, canalization, and evolvability. Proponents of fluctuating asymmetry as a bioindicator of environmental or genetic stress, often make the assumption that developmental noise is minimal and, therefore, that phenotype can respond sensitively to the environment. However, biologists still have not measured whether developmental noise actually comprises a significant fraction of the overall environmental response of fluctuating asymmetry observed within a population. Results In a morphometric study designed to partition developmental noise from fluctuating asymmetry in the wing morphology of a monoclonal culture of cotton aphid, Aphis gossipyii, it was discovered that fluctuating asymmetry in the aphid wing was nearly four times higher than in other insect species. Also, developmental noise comprised a surprisingly large fraction (≈ 50% of the overall response of fluctuating asymmetry to a controlled graded temperature environment. Fluctuating asymmetry also correlated negatively with temperature, indicating that environmentally-stimulated changes in developmental instability are mediated mostly by changes in the development time of individuals

  5. Influence of Plant Diversity on the Numerical Response of Eriopis connexa (Coleoptera: Coccinellidae to Changes in Cereal Aphid Density in Wheat Crops

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    María C. Tulli

    2013-01-01

    Full Text Available Cereal aphids cause economic injury to wheat crops. In Argentina, Eriopis connexa is an indigenous ladybird. In the present study, the numerical response of E. connexa to changes in aphid density on wheat crops with high and low plant diversity was investigated. The study was carried out in Balcarce, Buenos Aires, Argentina, from September to December 2007 and 2008, on two wheat crops with either a higher plant diversity (HPD with refuge strips or a lower plant diversity (LPD without refuge strips. Crops were sampled every week and the abundance of aphids and E. connexa was recorded. The dominant aphid species were Schizaphis graminum, Metopolophium dirhodum, and Sitobion avenae. Eriopis connexa showed a linear increase in the numerical response to an increase in aphid density, which varied in space and time. The abundance of E. connexa increased in relation to the crop development and aphid population and was higher in the HPD than in the LPD system. This predator increased its reproductive numerical response only in 2008, with a significant liner response in the HPD system. This suggests that the potential of E. connexa as a predator of cereal aphids also increases directly in proportion to landscape vegetal diversity.

  6. Infestation of potato (Solanum tuberosum L.) by the peach-potato aphid (Myzus persicae Sulzer) alters cellular redox status and is influenced by ascorbate.

    Science.gov (United States)

    Kerchev, Pavel I; Fenton, Brian; Foyer, Christine H; Hancock, Robert D

    2012-02-01

    The peach-potato aphid (Myzus persicae Sulzer) is a major pest of potato (Solanum tuberosum L.) but the molecular characterization of this interaction particularly with regard to oxidants and antioxidants remains to be undertaken. Aphid colonies reared on potato leaves containing high ascorbate were twice the size of those grown on leaves with low ascorbate. Infestation-dependent decreases in the abundance of key transcripts such as chloroplastic FeSOD, peroxisomal catalase 2, PR1 and JAZ1 preceded detectable leaf H(2)O(2) or polyphenol accumulation. The leaf glutathione pool was increased 48 h after infestation, but the amount of ascorbate was unchanged. The ascorbate/dehydroacorbate (DHA) ratio was lower at 48 h but the ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG) was unchanged. While DHA reductase and GSSG reductase activities were unaffected by aphid feeding, non-specific peroxidase activities were enhanced 48 h following aphid infestation. Brown ethanol-insoluble deposits were observed close to leaf veins following aphid infestation. Taken together, the results demonstrate that high ascorbate favours aphid colony expansion and that perturbations in the leaf antioxidant system are intrinsic to the potato leaf response to aphids. Moreover, these changes together with the induction of hormone-related transcripts precede the deposition of defence-associated oxidized polyphenols along the stylet track.

  7. Alteration of intersubunit acid–base pair interactions at the quasi-threefold axis of symmetry of Cucumber mosaic virus disrupts aphid vector transmission

    Energy Technology Data Exchange (ETDEWEB)

    Bricault, Christine A. [Department of Plant Pathology and Plant-Microbe Biology, 334 Plant Science Building, Cornell University, Ithaca, NY 14850 (United States); Perry, Keith L., E-mail: KLP3@cornell.edu [Department of Plant Pathology and Plant-Microbe Biology, 334 Plant Science Building, Cornell University, Ithaca, NY 14850 (United States)

    2013-06-05

    In the atomic model of Cucumber mosaic virus (CMV), six amino acid residues form stabilizing salt bridges between subunits of the asymmetric unit at the quasi-threefold axis of symmetry. To evaluate the effects of these positions on virion stability and aphid vector transmissibility, six charged amino acid residues were individually mutated to alanine. All of the six engineered viruses were viable and exhibited near wild type levels of virion stability in the presence of urea. Aphid vector transmissibility was nearly or completely eliminated in the case of four of the mutants; two mutants demonstrated intermediate aphid transmissibility. For the majority of the engineered mutants, second-site mutations were observed following aphid transmission and/or mechanical passaging, and one restored transmission rates to that of the wild type. CMV capsids tolerate disruption of acid–base pairing interactions at the quasi-threefold axis of symmetry, but these interactions are essential for maintaining aphid vector transmissibility. - Highlights: ► Amino acids between structural subunits of Cucumber mosaic virus affect vector transmission. ► Mutant structural stability was retained, while aphid vector transmissibility was disrupted. ► Spontaneous, second-site mutations restored aphid vector transmissibility.

  8. Leaf surface factors of transgenic Bt cotton associated with the feeding behaviors of cotton aphids: a case study on non-target effects.

    Science.gov (United States)

    Xue, Kun; Deng, Su; Wang, RongJiang; Yan, FengMing; Xu, ChongRen

    2008-02-01

    The present paper reports case study results of the risk assessment of transgenic Bt cotton on a non-target pest, cotton aphid, Aphis gossypii. Several types of techniques, i.e., electrical penetration graph (EPG), light and electron microscopy, bioassays and chemical analysis, were applied to investigate physical and chemical leaf factors of 2 transgenic Bt cotton lines (GK12 and GK19) and their parental non-Bt cotton line (Simian3) associated with searching and feeding behaviors of cotton aphids on leaves or leaf extracts of cotton plants. EPG results showed that there were some differences among behaviors of cotton aphids on 2 Bt cotton and 1 non-Bt cotton lines. Cotton aphids performed similarly to leaf surface extracts from 3 cotton lines; and leaf surface chemicals, mainly volatiles and waxes, were almost identical in the components and concentrations among the cotton lines. However, three cotton lines were quite different from each other in the densities of certain kinds of covering trichomes. Therefore, the relationships between the physical characteristics and the searching behaviors of cotton aphids on the three cotton lines were constructed as the regression equations. Glandular trichomes and covering trichomes with 5 branches influenced the cotton aphids' searching behaviors effectively; and other trichomes with other branches affected aphids in varying ways. These results demonstrated that leaf surface physical factors of transgenic Bt cotton lines different from their parental non-Bt line could affect the penetration behaviors of non-target cotton aphids. Cotton aphids penetrate and feed more easily on two Bt cotton lines than on the non-Bt cotton line.

  9. Leaf surface factors of transgenic Bt cotton associated with the feeding behaviors of cotton aphids: A case study on non-target effects

    Institute of Scientific and Technical Information of China (English)

    XUE Kun; DENG Su; WANG RongJiang; YAN FengMing; XU ChongRen

    2008-01-01

    The present paper reports case study results of the risk assessment of transgenic Bt cotton on a non-target pest, cotton aphid, Aphis gossypii. Several types of techniques, i.e., electrical penetration graph (EPG), light and electron microscopy, bioessays and chemical analysis, were applied to investigate physical and chemical leaf factors of 2 transgenic Bt cotton lines(GK12 and GK19) and their parental non-Bt cotton line (Simian3) associated with searching and feeding behaviors of cotton aphids on leaves or leaf extracts of cotton plants. EPG results showed that there were some differences among behaviors of cotton aphids on 2 Bt cotton and 1 non-Bt cotton lines. Cotton aphids performed similarly to leaf surface extracts from 3 cotton lines; and leaf surface chemicals, mainly volatiles and waxes,were almost identical in the components and concentrations among the cotton lines. However, three cotton lines were quite different from each other in the densities of certain kinds of covering trichomes.Therefore, the relationships between the physical characteristics and the searching behaviors of cotton aphids on the three cotton lines were constructed as the regression equations. Glandular trichomes and covering trichomes with 5 branches Influenced the cotton aphids' searching behaviors effectively;and other trichomes with other branches affected aphids in varying ways. These results demonstrated that leaf surface physical factors of transgenic Bt cotton lines different from their parental non-Bt line could affect the penetration behaviors of non-target cotton aphids. Cotton aphids penetrate and feed more easily on two Bt cotton lines than on the non-Bt cotton line.

  10. Tritrophic interactions between transgenic potato expressing snowdrop lectin (GNA), an aphid pest (peach-potato aphid; Myzus persicae (Sulz.) and a beneficial predator (2-spot ladybird; Adalia bipunctata L.).

    Science.gov (United States)

    Down, Rachel E; Ford, Louise; Woodhouse, Stephen D; Davison, Gillian M; Majerus, Michael E N; Gatehouse, John A; Gatehouse, Angharad M R

    2003-04-01

    Tritrophic interactions between transgenic potato expressing the insecticidal lectin from snowdrop (Galanthus nivalis agglutinin; GNA), an aphid pest, Myzus persicae (Sulz.), and a beneficial predator, the 2-spot ladybird (Adalia bipunctata L.) were investigated. Clonal plants expressing GNA at 0.1-0.2% total soluble protein in leaves were used. No significant effects on development and survival of ladybird larvae fed on aphids from these transgenic plants were observed, with larval survival in the experimental group being 90% compared to 89% for controls. There were also no effects on subsequent female or male longevity. Female fecundity was also investigated. Although no significant differences (p > 0.05) were observed in egg production between control and experimental groups, a 10%, reduction (p < 0.01) in egg viability (determined by % hatch) occurred in ladybirds fed aphids reared on transgenic plants. Additional studies were carried out using aphids fed on artificial diet containing GNA, to deliver quantified levels of the protein to ladybird adults. GNA had no deleterious effects upon adult longevity, but resulted in a consistent trend for improved fecundity. Egg production was increased by up to 70% and egg viability also increased significantly. The results suggest that GNA is not deleterious to ladybirds. Results from these studies highlight the need to discriminate between direct and indirect effects when studying tritrophic interactions between plants/pests/natural enemies. Furthermore, it emphasises the importance of demonstrating 'cause and effect'.

  11. Alkali-Soluble Pectin Is the Primary Target of Aluminum Immobilization in Root Border Cells of Pea (Pisum sativum).

    Science.gov (United States)

    Yang, Jin; Qu, Mei; Fang, Jing; Shen, Ren Fang; Feng, Ying Ming; Liu, Jia You; Bian, Jian Feng; Wu, Li Shu; He, Yong Ming; Yu, Min

    2016-01-01

    We investigated the hypothesis that a discrepancy of Al binding in cell wall constituents determines Al mobility in root border cells (RBCs) of pea (Pisum sativum), which provides protection for RBCs and root apices under Al toxicity. Plants of pea (P. sativum L. 'Zhongwan no. 6') were subjected to Al treatments under mist culture. The concentration of Al in RBCs was much higher than that in the root apex. The Al content in RBCs surrounding one root apex (10(4) RBCs) was approximately 24.5% of the total Al in the root apex (0-2.5 mm), indicating a shielding role of RBCs for the root apex under Al toxicity. Cell wall analysis showed that Al accumulated predominantly in alkali-soluble pectin (pectin 2) of RBCs. This could be attributed to a significant increase of uronic acids under Al toxicity, higher capacity of Al adsorption in pectin 2 [5.3-fold higher than that of chelate-soluble pectin (pectin 1)], and lower ratio of Al desorption from pectin 2 (8.5%) compared with pectin 1 (68.5%). These results indicate that pectin 2 is the primary target of Al immobilization in RBCs of pea, which impairs Al access to the intracellular space of RBCs and mobility to root apices, and therefore protects root apices and RBCs from Al toxicity.

  12. Non-host disease resistance response in pea (Pisum sativum) pods: Biochemical function of DRR206 and phytoalexin pathway localization.

    Science.gov (United States)

    Seneviratne, Herana Kamal; Dalisay, Doralyn S; Kim, Kye-Won; Moinuddin, Syed G A; Yang, Hong; Hartshorn, Christopher M; Davin, Laurence B; Lewis, Norman G

    2015-05-01

    Continually exposed to potential pathogens, vascular plants have evolved intricate defense mechanisms to recognize encroaching threats and defend themselves. They do so by inducing a set of defense responses that can help defeat and/or limit effects of invading pathogens, of which the non-host disease resistance response is the most common. In this regard, pea (Pisum sativum) pod tissue, when exposed to Fusarium solani f. sp. phaseoli spores, undergoes an inducible transcriptional activation of pathogenesis-related genes, and also produces (+)-pisatin, its major phytoalexin. One of the inducible pathogenesis-related genes is Disease Resistance Response-206 (DRR206), whose role in vivo was unknown. DRR206 is, however, related to the dirigent protein (DP) family. In this study, its biochemical function was investigated in planta, with the metabolite associated with its gene induction being pinoresinol monoglucoside. Interestingly, both pinoresinol monoglucoside and (+)-pisatin were co-localized in pea pod endocarp epidermal cells, as demonstrated using matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging. In addition, endocarp epidermal cells are also the site for both chalcone synthase and DRR206 gene expression. Taken together, these data indicate that both (+)-pisatin and pinoresinol monoglucoside function in the overall phytoalexin responses.

  13. SGRL can regulate chlorophyll metabolism and contributes to normal plant growth and development in Pisum sativum L.

    Science.gov (United States)

    Bell, Andrew; Moreau, Carol; Chinoy, Catherine; Spanner, Rebecca; Dalmais, Marion; Le Signor, Christine; Bendahmane, Abdel; Klenell, Markus; Domoney, Claire

    2015-12-01

    Among a set of genes in pea (Pisum sativum L.) that were induced under drought-stress growth conditions, one encoded a protein with significant similarity to a regulator of chlorophyll catabolism, SGR. This gene, SGRL, is distinct from SGR in genomic location, encoded carboxy-terminal motif, and expression through plant and seed development. Divergence of the two encoded proteins is associated with a loss of similarity in intron/exon gene structure. Transient expression of SGRL in leaves of Nicotiana benthamiana promoted the degradation of chlorophyll, in a manner that was distinct from that shown by SGR. Removal of a predicted transmembrane domain from SGRL reduced its activity in transient expression assays, although variants with and without this domain reduced SGR-induced chlorophyll degradation, indicating that the effects of the two proteins are not additive. The combined data suggest that the function of SGRL during growth and development is in chlorophyll re-cycling, and its mode of action is distinct from that of SGR. Studies of pea sgrL mutants revealed that plants had significantly lower stature and yield, a likely consequence of reduced photosynthetic efficiencies in mutant compared with control plants under conditions of high light intensity.

  14. Differential Gene Expression in the Meristem and during Early Fruit Growth of Pisum sativum L. Identifies Potential Targets for Breeding

    Science.gov (United States)

    Smitha Ninan, Annu; Shah, Anish; Song, Jiancheng; Jameson, Paula E.

    2017-01-01

    For successful molecular breeding it is important to identify targets to the gene family level, and in the specific species of interest, in this case Pisum sativum L. The cytokinins have been identified as a key breeding target due to their influence on plant architecture, and on seed size and sink activity. We focused on the cytokinin biosynthetic gene family (the IPTs) and the gene family key to the destruction of cytokinins (the CKXs), as well as other gene families potentially affected by changing cytokinin levels. These included key meristem genes (WUS and BAM1) and the transporter gene families, sucrose transporters (SUTs) and amino acid permeases (AAPs). We used reverse transcription quantitative PCR (RT-qPCR) to monitor gene expression in the vegetative meristem and in pre- and post-fertilisation young pea fruits. PsWUS expression was specific to the shoot apical meristem while PsBAM1 was highly expressed in the shoot apical meristem (SAM) but was also expressed at a low level in the young fruit. Differential expression was shown between genes and within gene families for IPT, CKX, SUT, and AAP. PsCKX7 showed strong gene family member-specific expression in the SAM, and was also expressed in young pea fruits. We suggest that PsCKX7 is a potential target for downregulation via molecular breeding or gene editing. PMID:28212324

  15. Differential Gene Expression in the Meristem and during Early Fruit Growth of Pisum sativum L. Identifies Potential Targets for Breeding

    Directory of Open Access Journals (Sweden)

    Annu Smitha Ninan

    2017-02-01

    Full Text Available For successful molecular breeding it is important to identify targets to the gene family level, and in the specific species of interest, in this case Pisum sativum L. The cytokinins have been identified as a key breeding target due to their influence on plant architecture, and on seed size and sink activity. We focused on the cytokinin biosynthetic gene family (the IPTs and the gene family key to the destruction of cytokinins (the CKXs, as well as other gene families potentially affected by changing cytokinin levels. These included key meristem genes (WUS and BAM1 and the transporter gene families, sucrose transporters (SUTs and amino acid permeases (AAPs. We used reverse transcription quantitative PCR (RT-qPCR to monitor gene expression in the vegetative meristem and in pre- and post-fertilisation young pea fruits. PsWUS expression was specific to the shoot apical meristem while PsBAM1 was highly expressed in the shoot apical meristem (SAM but was also expressed at a low level in the young fruit. Differential expression was shown between genes and within gene families for IPT, CKX, SUT, and AAP. PsCKX7 showed strong gene family member-specific expression in the SAM, and was also expressed in young pea fruits. We suggest that PsCKX7 is a potential target for downregulation via molecular breeding or gene editing.

  16. Remote sensing study of the influence of herbicides on the spectral reflectance of pea plant leaves (Pisum sativum L.)

    Science.gov (United States)

    Krezhova, D.; Alexieva, V.; Yanev, T.; Ivanov, S.

    Results from a remote sensing study of spectral reflectance of leaves of pea plants Pisum sativum L treated by the herbicides atrazine 2 4-D glyphosate fluridone and chlorsulfuron are reported According to the classification of the Herbicide Action Committee reflecting their mode of action they belong to different groups photosystem II bloker - C1 atrazine synthetic auxins - O 2 4-D inhibition of EPSP synthase - G glyphosate photobleaching - F1 fluridone and inhibition of acetoctate synthase - B chlorsulfuron The plants studied were grown hydroponically in a growth chamber in a nutritious medium to which every herbicide was added at three low concentrations 1 mu M 0 1 mu M and 0 01 mu M with respect to the field dose applied in the agricultural practice The spectral measurements of the leaf spectral reflectance were carried out in laboratory using a multichannel spectrometer in the visible and near infrared regions of the spectrum 480 div 810 nm Data was registered in 128 channels at a high spectral resolution of 2 6 nm halfwidth and a spatial resolution of 2 mm 2 The reflectance spectra were obtained from the leaf-reflected radiation referenced against a standard white screen To assess the changes arising in the leaf spectral reflectance under the herbicide action the developed by us approach based on discriminant analysis and other statistical methods was applied The spectral reflectance characteristics SRC were investigated in three spectral intervals 520 div 580 nm region of maximal

  17. Pinolide, a new nonenolide produced by Didymella pinodes , the causal agent of ascochyta blight on Pisum sativum.

    Science.gov (United States)

    Cimmino, Alessio; Andolfi, Anna; Fondevilla, Sara; Abouzeid, Mohamed A; Rubiales, Diego; Evidente, Antonio

    2012-05-30

    An aggressive isolate of Didymella pinodes isolated from pea ( Pisum sativum ) produced four different metabolites in vitro. The metabolites isolated from the culture filtrates were characterized by spectroscopic and optical methods. A new nonenolide, named pinolide, was isolated and characterized as (2S*,7R*,8S*,5E,9R*)-2,7,8-trihydroxy-9-propyl-5-nonen-9-olide. Pinolidoxin, the main toxin produced by D. pinodes, was also isolated together with two other closely related nonenolides, identified as herbarumin II and 2-epi-herbarumin II. Herbarumin II and 2-epi-herbarumin II have been previously isolated from the fungi Phoma herbarum and Paraphaeosphaeria recurvifoliae , respectively, but described here to be isolated for the first time from D. pinodes. When tested on leaves of the host plant and other legumes and weeds, pinolidoxin was phytotoxic in all of the plant species, whereas the other three nonenolides did not produce any symptoms. The importance of the stereochemistry of the hydroxy group at C-7 on phytotoxicity also is discussed.

  18. [Research progress on the cloning of Mendel's gene in pea (Pisum sativum L.) and its application in genetics teaching].

    Science.gov (United States)

    He, Feng-Hua; Zhu, Bi-Yan; Gao, Feng; Li, Shao-Shan; Li, Niang-Hui

    2013-07-01

    One hundred and fifty years ago, Gregor Mendel investigated the segregation of seven traits in pea (Pisum sativum) and established the law of segregation and the law of independent assortment in genetics. After the two laws of genetics were rediscovered in 1900, the seven traits have been extensively investigated in the fields of plant physiology and biochemistry as well as in the cell and molecular levels. Recently, with the development of molecular technology in genetics, four genes for seed shape (R), stem length (Le), cotyledon colour (I), and flower colour (A) have been cloned and sequenced; and another three genes for immature pod colour (Gp), fasciation (Fa) and pod form (V) have been located in the linkage groups, respectively. The identification and cloning of the four Mendel's genes will help deeply understand the basic concept of gene in many respects: like the diversity of gene function, the different origins for gene mutation in molecular level, and the molecular nature of a dominant gene or a recessive gene. In teaching of genetics, the introduction of most recent research advancements of cloning of Mendel's genes to the students and the interpretation of the Mendel's laws in molecular level will help students promote their learning interests in genetics and help students grasp the whole content from classical genetics to molecular genetics and the developmental direction of this subject.

  19. Digestion by pigs of non-starch polysaccharides in wheat and raw peas (Pisum sativum) fed in mixed diets.

    Science.gov (United States)

    Goodlad, J S; Mathers, J C

    1991-03-01

    The digestion by pigs of non-starch polysaccharides (NSP) in wheat and raw peas (Pisum sativum) fed in mixed diets was measured. In the four experimental diets, wheat was included at a constant 500 g/kg whilst peas contributed 0-300 g/kg and these were the only dietary sources of NSP. Separate estimates of digestibility for wheat and peas were obtained by using a multiple linear regression technique which also tested the possibility that the presence of peas might influence the digestibility of wheat NSP. There was little evidence of the latter and it was found that the digestibility of peas NSP (0.84) was considerably greater than that of wheat (0.65). The non-cellulosic polysaccharides (NCP) had twofold greater digestibilities than had cellulose for both foods with essentially all the peas NCP being digested. Faecal alpha, epsilon-diaminopimelic acid concentration increased with feeding of peas, suggesting stimulation of bacterial biomass production in the large intestine using the readily fermented peas NSP. All three major volatile fatty acids produced by large intestinal fermentation were detected in jugular blood and increased significantly with increasing peas inclusion rate in the diet.

  20. Alkali-Soluble Pectin Is the Primary Target of Aluminum Immobilization in Root Border Cells of Pea (Pisum sativum)

    Science.gov (United States)

    Yang, Jin; Qu, Mei; Fang, Jing; Shen, Ren Fang; Feng, Ying Ming; Liu, Jia You; Bian, Jian Feng; Wu, Li Shu; He, Yong Ming; Yu, Min

    2016-01-01

    We investigated the hypothesis that a discrepancy of Al binding in cell wall constituents determines Al mobility in root border cells (RBCs) of pea (Pisum sativum), which provides protection for RBCs and root apices under Al toxicity. Plants of pea (P. sativum L. ‘Zhongwan no. 6’) were subjected to Al treatments under mist culture. The concentration of Al in RBCs was much higher than that in the root apex. The Al content in RBCs surrounding one root apex (104 RBCs) was approximately 24.5% of the total Al in the root apex (0–2.5 mm), indicating a shielding role of RBCs for the root apex under Al toxicity. Cell wall analysis showed that Al accumulated predominantly in alkali-soluble pectin (pectin 2) of RBCs. This could be attributed to a significant increase of uronic acids under Al toxicity, higher capacity of Al adsorption in pectin 2 [5.3-fold higher than that of chelate-soluble pectin (pectin 1)], and lower ratio of Al desorption from pectin 2 (8.5%) compared with pectin 1 (68.5%). These results indicate that pectin 2 is the primary target of Al immobilization in RBCs of pea, which impairs Al access to the intracellular space of RBCs and mobility to root apices, and therefore protects root apices and RBCs from Al toxicity. PMID:27679639

  1. Massive Analysis of cDNA Ends (MACE for transcript-based marker design in pea (Pisum sativum L.

    Directory of Open Access Journals (Sweden)

    Aleksandr Zhernakov

    2017-03-01

    Full Text Available Aimed at gene-based markers design, we generated and analyzed transcriptome sequencing datasets for six pea (Pisum sativum L. genetic lines that have not previously been massively genotyped. Five cDNA libraries obtained from nodules or nodulated roots of genetic lines Finale, Frisson, Sparkle, Sprint-2 and NGB1238 were sequenced using a versatile 3′-RNA-seq protocol called MACE (Massive Analysis of cDNA Ends. MACE delivers a single next-generation sequence from the 3′-end of each individual cDNA molecule that precisely quantifies the respective transcripts. Since the contig generated from the 3′-end of the cDNA by assembling all sequences encompasses the highly polymorphic 3′-untranslated region (3′-UTR, MACE efficiently detects single nucleotide variants (SNVs. Mapping MACE reads to the reference nodule transcriptome assembly of the pea line SGE (Transcriptome Shotgun Assembly GDTM00000000.1 resulted in characterization of over 34,000 polymorphic sites in more than 9700 contigs. Several of these SNVs were located within recognition sequences of restriction endonucleases which allowed the design of co-dominant CAPS markers for the particular transcript. Cleaned reads of sequenced libraries are available from European Nucleotide Archive (http://www.ebi.ac.uk/ under accessions PRJEB18101, PRJEB18102, PRJEB18103, PRJEB18104, PRJEB17691.

  2. Faba bean (Vicia faba minor and pea seeds (Pisum sativum as protein sources in lactating ewes’ diets.

    Directory of Open Access Journals (Sweden)

    D. Gatta

    2010-04-01

    Full Text Available 18 Massese lactating ewes, divided into 3 homogeneous groups for parity and milk yield, were used to evaluate the replacement effects of soybean meal by Faba bean (Vicia faba minor and Pea (Pisum sativum seeds. During a 70 days trial (beginning after weaning: 30±1.5 days after lambing animals were fed three isonitrogenous and isocaloric diets. Each diet was characterised by the presence of only one protein feed. The diets consisted of alfalfa hay (1.1 kg/head/d and a decreasing amount of mixed feed (from 1.1 to 0.7 kg/head/d to fit animals’ requirements. Milk yield, milk chemical composition, animals live weight and BCS, health state and hematochemical parameters were regularly monitored. No diets palatability problems were detected. No significant differences resulted for live weight, BCS, milk yield and milk chemical composition, except for milk protein: higher for faba bean (6.54% and soybean (6.39% respect pea (5.66% diets, P<0.05. No differences resulted for blood parameters too and no clinical signs of illness were observed. Therefore faba bean and pea seeds seem to be able to replace the soybean well.

  3. Proteomic Profiling of the Microsomal Root Fraction: Discrimination of Pisum sativum L. Cultivars and Identification of Putative Root Growth Markers

    Science.gov (United States)

    Meisrimler, Claudia-Nicole; Wienkoop, Stefanie; Lüthje, Sabine

    2017-01-01

    Legumes are a large and economically important family, containing a variety of crop plants. Alongside different cereals, some fruits, and tropical roots, a number of leguminosae evolved for millennia as crops with human society. One of these legumes is Pisum sativum L., the common garden pea. In the past, breeding has been largely selective on improved above-ground organs. However, parameters, such as root-growth, which determines acquisition of nutrients and water, have largely been underestimated. Although the genome of P. sativum is still not fully sequenced, multiple proteomic studies have been published on a variety of physiological aspects in the last years. The presented work focused on the connection between root length and the influence of the microsomal root proteome of four different pea cultivars after five days of germination (cultivar Vroege, Girl from the Rhineland, Kelvedon Wonder, and Blauwschokker). In total, 60 proteins were identified to have significantly differential abundances in the four cultivars. Root growth of five-days old seedlings and their microsomal proteome revealed a similar separation pattern, suggesting that cultivar-specific root growth performance is explained by differential membrane and ribosomal protein levels. Hence, we reveal and discuss several putative root growth protein markers possibly playing a key role for improved primary root growth breeding strategies. PMID:28257117

  4. Genetic diversity of root-nodulating bacteria isolated from pea (Pisum sativum) in subtropical regions of China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Diversity of 42 isolates from effective nodules of Pisum sativum in different geographical regions of China were studied using 16S rRNA gene RFLP patterns, 16S rRNA sequencing, 16S–23S rRNA inter-genic spacer (IGS) region RFLP patterns and G-C rich random amplified polymorphic DNA (RAPD). The isolates were distributed in two groups on the basis of their 16S rRNA gene RFLP patterns. The 16S rRNA gene sequences of strains from 16S rRNA gene RFLP patterns group I were very closely related (identities higher than 99.5%) to Rhizobium leguminosarum USDA 2370. Group II consisting of WzP3 and WzP15 was closely related to Rhizobium etli CFN42. The analysis of the 16S–23S IGS RFLP pat-terns divided the isolates into 18 genotypes and four groups. Group I was clustered with R. legumino-sarum USDA2370. Group II consisted of YcP2, YcP3 and CqP7. The strains of group III were distributed abroad. Group IV consisted of WzP3, WzP15 and R. etli CFN42. RAPD divided the isolates into nine clusters in which group IV only consisted of YcP2 and the strains of group V and IX were from Wenzhou and Xiantao, respectively. This assay demonstrated the geographical effect on genetic diversity of pea rhizobia.

  5. Genetic diversity of root-nodulating bacteria isolated from pea (Pisum sativum) in subtropical regions of China

    Institute of Scientific and Technical Information of China (English)

    YANG ChengYun; YANG JiangKe; LI YouGuo; ZHOU JunOhu

    2008-01-01

    Diversity of 42 isolates from effective nodules of Pisum sativum in different geographical regions of China were studied using 16S rRNA gene RFLP patterns, 16S rRNA sequencing, 16S-23S rRNA inter-genic spacer (IGS) region RFLP patterns and G-C rich random amplified polymorphic DNA (RAPD). The isolates were distributed in two groups on the basis of their 16S rRNA gene RFLP patterns. The 16S rRNA gene sequences of strains from 16S rRNA gene RFLP patterns group Ⅰ were very closely related (identities higher than 99.5%) to Rhizobium leguminosarum USDA 2370. Group Ⅱ consisting of WzP3 and WzP15 was closely related to Rhizobium etli CFN42. The analysis of the 16S-23S IGS RFLP pat-terns divided the isolates into 18 genotypes and four groups. Group Ⅰ was clustered with R. legumino-sarum USDA2370. Group Ⅱ consisted of YcP2, YcP3 and CqP7. The strains of group Ⅲ were distributed abroad. Group Ⅳ consisted of WzP3, WzP15 and R. etli CFN42. RAPD divided the isolates into nine clusters in which group Ⅳ only consisted of YcP2 and the strains of group Ⅴ and Ⅸ were from Wenzhou and Xiantao, respectively. This assay demonstrated the geographical effect on genetic diversity of pea rhizobia.

  6. THE EFFECT OF INDUSTRIAL WATER ON THE GERMINATION OF SEEDS AND THE DEVELOPMENT OF SEEDLINGS OF PISUM SATIVUM L.

    Directory of Open Access Journals (Sweden)

    Liliana Cristina SOARE

    2011-01-01

    Full Text Available The aim of the research was to highlight the influence of industrial water on the germination of seeds and the development of seedlings of Pisum sativum L., so that the impact of these water on the plants may be assessed, in case of accidental spills. The analysis of polluted industrial water indicates the presence of Cr, Fe, Ni, Pb, Cd, Cu, and Zn concentrations higher than CMA, except Cd, which was below the detection limit, and Cu. On leaving the neutralization station, metal concentration was below the CMA, except Pb. The early ontogenetic stages of root development were much more sensitive to water pollution. For the experimental variants where the seeds were immersed in water treated and discharged from the neutralization station, there were no significant differences between the experimental variants, which also confirms the results of the chemical analysis. The metals absorbed by the roots were translocated into the stem, which affected its growth processes. Along with the increased dilution in the polluted water, the average stem length also increased, which was also true of the root growth. Root and stem growth can represent biomarkers of environmental pollution by metals.

  7. Resistance and susceptibility of alfalfa (Medicago sativa L.) cultivars to the aphid Therioaphis maculata (Homoptera:Aphididae): insect biology and cultivar evaluation

    Institute of Scientific and Technical Information of China (English)

    ALEXANDRE DE ALMEIDA E SILVA; ELENICE MOURO VARANDA; JOS(E) RICARDO BAROSELA

    2006-01-01

    Biology of the aphid Therioaphis maculata was studied on alfalfa (Medicago sativa L.), including four resistant (Mesa-Sirsa, CUF101, Baker and Lahontan) and two susceptible (ARC and Caliverde) alfalfa cultivars, and one of the most cropped Brazilian cultivars, Crioula. Under controlled conditions, antibiosis (i.e., reduced longevity, fecundity and increased mortality of the aphid) was observed mainly on the resistant alfalfa cultivars,except on Lahontan. Crioula seemed to be tolerant to aphids. Present data support geographic limitation usage of cultivars, and we suggest Baker and Mesa-Sirsa as sources of antibiosis,and provide biological information of a tropical T. maculata biotype on alfalfa.

  8. Sample collection method and sequential sampling plan for mites Oligonychus ununquis and Aphids cinaria laricifex on tamarack. Technical note No. 278

    Energy Technology Data Exchange (ETDEWEB)

    1993-01-01

    Spider mite and aphid infestations are a recurrent problem in a number of seed orchards in New Brunswick. A study was carried out to develop suitable sampling methods for routine assessment of black larch aphid (Cinaria laricifex) and spruce spider mite (Oligonychus ununquis) populations on tamarack and black spruce. Tamarack was chosen because population levels of black larch aphid and spruce spider mite have been traditionally high. Sample collection procedures, sample processing/counting, sequential sampling, and use of the sequential sampling plan are discussed.

  9. Efficacy of mineral oil combined with insecticides for the control of aphid virus vectors to reduce potato virus Y infections in seed potatoes (Solanum tuberosum)

    DEFF Research Database (Denmark)

    Hansen, Lars M.; Nielsen, Steen L.

    2012-01-01

    with a combination of mineral oil and insecticides. In 2005 and 2007 when a very high number of aphids were present, nearly all plants were infected with PVY. In 2006 with a lower number of aphids a smaller proportion of the plants were infected, and a tendency to a lower PVY incidence in mineral-oil treated plots...... was found, but more than the 8% threshold value. Even in plots where systemic neonicotinoids were applied and very few aphids were recorded, no significant reduction in infestation level of PVY was found. The present experiment shows that mineral oil and insecticides applied to potato crops each week...

  10. Wheat containing snowdrop lectin (GNA) does not affect infection of the cereal aphid Metopolophium dirhodum by the fungal natural enemy Pandora neoaphidis.

    Science.gov (United States)

    Shah, P A; Gatehouse, A M R; Clark, S J; Pell, J K

    2005-08-01

    Studies were carried out to determine if susceptibility of the cereal aphid Metopolophium dirhodum to the fungus Pandora neoaphidis was affected by wheat expressing snowdrop lectin (GNA). Aphid infection did not differ significantly between the transgenic GNA and non-transformed lines (91 and 82%, respectively). Fecundity also did not differ between aphids on the two lines, and was ca. 18 nymphs adult(-1). Time to infection was ca. 5 days for M. dirhodum on both lines in two of three assays. Our results indicate that wheat expressing GNA would not compromise the efficacy of P. neoaphidis as a biocontrol agent.

  11. Transgenic Bt Cotton Does Not Disrupt the Top-Down Forces Regulating the Cotton Aphid in Central China

    Science.gov (United States)

    Yao, Yong-Sheng; Han, Peng; Niu, Chang-Ying; Dong, Yong-Cheng; Gao, Xi-Wu; Cui, Jin-Jie; Desneux, Nicolas

    2016-01-01

    Top-down force is referred to arthropod pest management delivered by the organisms from higher trophic levels. In the context of prevalent adoption of transgenic Bt crops that produce insecticidal Cry proteins derived from Bacillus thuringiensis (Bt), it still remains elusive whether the top-down forces are affected by the insect-resistant traits that introduced into the Bt crops. We explored how Bt cotton affect the strength of top-down forces via arthropod natural enemies in regulating a non-target pest species, the cotton aphid Aphis gossypii Glover, using a comparative approach (i.e. Bt cotton vs. conventional cotton) under field conditions. To determine top-down forces, we manipulated predation/parasitism exposure of the aphid to their natural enemies using exclusion cages. We found that the aphid population growth was strongly suppressed by the dominant natural enemies including Coccinellids, spiders and Aphidiines parasitoids. Coccinellids, spiders and the assemblage of other arthropod natural enemies (mainly lacewings and Hemipteran bugs) are similarly abundant in both plots, but with the parasitoid mummies less abundant in Bt cotton plots compared to the conventional cotton plots. However, the lower abundance of parasitoids in Bt cotton plots alone did not translate into differential top-down control on A. gossypii populations compared to conventional ones. Overall, the top-down forces were equally strong in both plots. We conclude that transgenic Bt cotton does not disrupt the top-down forces regulating the cotton aphid in central China. PMID:27870914

  12. Alfalfa (Medicago sativa L.) shoot saponins: identification and bio-activity by the assessment of aphid feeding.

    Science.gov (United States)

    Mazahery-Laghab, H; Yazdi-Samadi, B; Bagheri, M; Bagheri, A R

    2011-01-01

    Biochemical components in alfalfa (Medicago sativa L.), such as saponins, can act as protecting factors against bio-stresses. Saponins are also antifeedants and show oral toxicity towards higher and lower animals. Changes in saponins, such as variation in the carbon skeleton, or hydrolysis of saponin glycosides and other conjugates, may change their biological effects. The aims of this research were to study saponin variation in different growth stages of alfalfa and to investigate the biological role of saponins in the spotted alfalfa aphid, Therioaphis maculata. Saponins from alfalfa shoots in different growth stages were extracted, chemically purified and analysed by TLC. Specific saponins such as soyasaponin1 from root and shoot and two bisdesmosides of medicagenic acid, one from shoot and another from root tissues, were identified using reference compounds allowing changes in saponin composition during plant development in different shoot tissues of alfalfa to be assessed. The response of the alfalfa aphid to feeding on alfalfa in different growth stages was studied. No significant difference in the survival of aphids, from neonate to adult, was observed, but due to the antibiotic effects of saponins, two differences were found in the onset of nymph production and cumulative nymph production. The results show that the saponin composition in alfalfa changes with plant development and this, in turn, can often negatively affect the development of specific insect pests such as the spotted alfalfa aphid, suggesting a possible biological role of alfalfa saponins.

  13. Life history data of the rosy apple aphid Dysaphis plantaginea (Pass.) (Homopt., Aphididae) on plantain and as migrant to apple

    NARCIS (Netherlands)

    Blommers, L.H.M.; Helsen, H.H.M.; Vaal, F.W.N.M.

    2004-01-01

    The rosy apple aphid Dysaphis plantaginea (Passerini) is a key pest in western European apple orchards; the economic damage threshold is so low that outbreaks cannot be forecasted. A mass rearing of the species on plantain (Plantago lanceolata L.) was initiated, with the aim to infest apple trees wi

  14. Host plant defense against sugarcane aphid in sorghum and genetic mechanism of resistance to the new pest

    Science.gov (United States)

    Sugarcane aphid (SCA), Melanaphis sacchari (Zerhntner), is typically known as a key pest to sorghum and sugarcane in tropical and subtropical regions around the world. In 2013, this new invasive pest was found on grain sorghum plants in South and East Texas, and now it has already spread over 17 st...

  15. Microsatellite markers reveal a predominant sugarcane aphid (Homoptera: Aphididae) clone is found on sorghum in the United States

    Science.gov (United States)

    The sugarcane aphid, Melanaphis sacchari, has become a serious pest causing severe economic losses to sorghum grown in the southern United States (U.S.). Since its original detection in four states in 2013, M. sacchari on sorghum has now spread to 17 states. The presence of one or multiple genotype...

  16. Expression of an (E-β-farnesene synthase gene from Asian peppermint in tobacco affected aphid infestation

    Directory of Open Access Journals (Sweden)

    Xiudao Yu

    2013-10-01

    Full Text Available Aphids are major agricultural pests that cause significant yield losses in crop plants each year. (E-β-farnesene (EβF is the main or only component of an alarm pheromone involved in chemical communication within aphid species and particularly in the avoidance of predation. EβF also occurs in the essential oil of some plant species, and is catalyzed by EβF synthase. By using oligonucleotide primers designed from the known sequence of an EβF synthase gene from black peppermint (Mentha × piperita, two cDNA sequences, MaβFS1 and MaβFS2, were isolated from Asian peppermint (Mentha asiatica. Expression pattern analysis showed that the MaβFS1 gene exhibited higher expression in flowers than in roots, stems and leaves at the transcriptional level. Overexpression of MaβFS1 in tobacco plants resulted in emission of pure EβF ranging from 2.62 to 4.85 ng d− 1 g− 1 of fresh tissue. Tritrophic interactions involving peach aphids (Myzus persicae, and predatory lacewing (Chrysopa septempunctata larvae demonstrated that transgenic tobacco expressing MaβFS1 had lower aphid infestation. This result suggested that the EβF synthase gene from Asian peppermint could be a good candidate for genetic engineering of agriculturally important crop plants.

  17. Expression of an(E)-β-farnesene synthase gene from Asian peppermint in tobacco affected aphid infestation

    Institute of Scientific and Technical Information of China (English)

    Xiudao; Yu; Yongjun; Zhang; Youzhi; Ma; Zhaoshi; Xu; Genping; Wang; Lanqin; Xia

    2013-01-01

    Aphids are major agricultural pests that cause significant yield losses in crop plants each year.(E)-β-farnesene(EβF) is the main or only component of an alarm pheromone involved in chemical communication within aphid species and particularly in the avoidance of predation. EβF also occurs in the essential oil of some plant species, and is catalyzed by EβF synthase. By using oligonucleotide primers designed from the known sequence of an EβF synthase gene from black peppermint(Mentha × piperita), two cDNA sequences, MaβFS1 and MaβFS2, were isolated from Asian peppermint(Mentha asiatica). Expression pattern analysis showed that the MaβFS1 gene exhibited higher expression in flowers than in roots, stems and leaves at the transcriptional level. Overexpression of MaβFS1 in tobacco plants resulted in emission of pure EβF ranging from 2.62 to 4.85 ng d-1g-1of fresh tissue. Tritrophic interactions involving peach aphids(Myzus persicae), and predatory lacewing(Chrysopa septempunctata) larvae demonstrated that transgenic tobacco expressing MaβFS1 had lower aphid infestation. This result suggested that the EβF synthase gene from Asian peppermint could be a good candidate for genetic engineering of agriculturally important crop plants.

  18. Genetic diversity for Russian wheat aphid resistance as determined by genome-wide association mapping and inheritance in progeny

    Science.gov (United States)

    Russian wheat aphid (RWA) is an increasing problem on barley throughout the world. Genetic resistance has been identified and used to create barley germplasm and cultivars adapted to the US. Several mapping studies have been conducted to identify loci associated with resistance, but questions remain...

  19. Expression Patterns of Genes Involved in Ascorbate-Glutathione Cycle in Aphid-Infested Maize (Zea mays L.) Seedlings.

    Science.gov (United States)

    Sytykiewicz, Hubert

    2016-02-23

    Reduced forms of ascorbate (AsA) and glutathione (GSH) are among the most important non-enzymatic foliar antioxidants in maize (Zea mays L.). The survey was aimed to evaluate impact of bird cherry-oat aphid (Rhopalosiphum padi L.) or grain aphid (Sitobion avenae F.) herbivory on expression of genes related to ascorbate-glutathione (AsA-GSH) cycle in seedlings of six maize varieties (Ambrozja, Nana, Tasty Sweet, Touran, Waza, Złota Karłowa), differing in resistance to the cereal aphids. Relative expression of sixteen maize genes encoding isoenzymes of ascorbate peroxidase (APX1, APX2, APX3, APX4, APX5, APX6, APX7), monodehydroascorbate reductase (MDHAR1, MDHAR2, MDHAR3, MDHAR4), dehydroascorbate reductase (DHAR1, DHAR2, DHAR3) and glutathione reductase (GR1, GR2) was quantified. Furthermore, effect of hemipterans' attack on activity of APX, MDHAR, DHAR and GR enzymes, and the content of reduced and oxidized ascorbate and glutathione in maize plants were assessed. Seedling leaves of more resistant Z. mays varieties responded higher elevations in abundance of target transcripts. In addition, earlier and stronger aphid-triggered changes in activity of APX, MDHAR, DHAR and GR enzymes, and greater modulations in amount of the analyzed antioxidative metabolites were detected in foliar tissues of highly resistant Ambrozja genotype in relation to susceptible Tasty Sweet plants.

  20. Eriosomatine aphids (Hemiptera, Aphididae, Eriosomatinae) associated with moss and roots of conifer and willow in forests of the Pacific Northwest

    Science.gov (United States)

    Apterous adult morphs of eriosomatine aphids (Hemiptera, Aphididae, Eriosomatinae) associated with moss and/or roots of conifer or willow in forests of the Pacific Northwest including Alaska are described, illustrated, and keyed. In total, seven species (Clydesmithia canadensis Danielsson, Melaphis ...

  1. Reciprocal interactions between native and introduced populations of common milkweed, Asclepias syriaca, and the specialist aphid, Aphis nerii

    NARCIS (Netherlands)

    Bukovinszky, T.; Gols, R.; Agrawal, A.A.; Roge, C.; Bezemer, T.M.; Biere, A.; Harvey, J.A.

    2014-01-01

    Following its introduction into Europe (EU), the common milkweed (Asclepias syriaca) has been free of most specialist herbivores that are present in its native North American (NA) range, except for the oleander aphid Aphis nerii. We compared EU and NA populations of A. nerii on EU and NA milkweed po

  2. On damage, uncertainty and risk in supervised control: aphids and brown rust in winter wheat as an example.

    NARCIS (Netherlands)

    Rossing, W.A.H.

    1993-01-01

    In supervised control of pests and diseases real-time information on pest and disease intensity and cost-benefit analysis of decision alternatives are used to support farmers' decisions on pesticide application. This thesis focuses on improving supervised control in the pathosystem aphids - brown ru

  3. Natural flightless morphs of the ladybird beetle Adalia bipunctata improve biological control of aphids on single plants

    NARCIS (Netherlands)

    Lommen, S.T.E.; Middendorp, C.W.; Luijten, C.A.; Schelt, van J.; Brakefield, P.M.; Jong, de P.W.

    2008-01-01

    The challenge of using ladybird beetles for biological control of insect pests such as aphids is that the adult beetles tend to fly away from the host plants. Therefore, flightless ladybirds might improve biocontrol. There are several artificial ways to obtain flightless beetles, but it may be prefe

  4. Localization, Concentration, and Transmission Efficiency of Banana bunchy top virus in Four Asexual Lineages of Pentalonia aphids

    Directory of Open Access Journals (Sweden)

    Alberto Bressan

    2013-02-01

    Full Text Available Banana bunchy top virus (BBTV is the most destructive pathogenic virus of banana plants worldwide. The virus is transmitted in a circulative non-propagative manner by the banana aphid, Pentalonia nigronervosa Coquerel. In this work, we examined the localization, accumulation, and transmission efficiency of BBTV in four laboratory-established lineages of Pentalonia aphids derived from four different host plants: taro (Colocasia esculenta, heliconia (Heliconia spp., red ginger (Alpinia purpurata, and banana (Musa sp.. Mitochondrial sequencing identified three and one lineages as Pentalonia caladii van der Goot, a recently proposed species, and P. nigronervosa, respectively. Microsatellite analysis separated the aphid lineages into four distinct genotypes. The transmission of BBTV was tested using leaf disk and whole-plant assays, both of which showed that all four lineages are competent vectors of BBTV, although the P. caladii from heliconia transmitted BBTV to the leaf disks at a significantly lower rate than did P. nigronervosa. The concentration of BBTV in dissected guts, haemolymph, and salivary glands was quantified by real-time PCR. The BBTV titer reached similar concentrations in the guts, haemolymph, and salivary glands of aphids from all four lineages tested. Furthermore, immunofluorescence assays showed that BBTV antigens localized to the anterior midguts and the principal salivary glands, demonstrating a similar pattern of translocations across the four lineages. The results reported in this study showed for the first time that P. caladii is a competent vector of BBTV.

  5. Localization, concentration, and transmission efficiency of Banana bunchy top virus in four asexual lineages of Pentalonia aphids.

    Science.gov (United States)

    Watanabe, Shizu; Greenwell, April M; Bressan, Alberto

    2013-02-22

    Banana bunchy top virus (BBTV) is the most destructive pathogenic virus of banana plants worldwide. The virus is transmitted in a circulative non-propagative manner by the banana aphid, Pentalonia nigronervosa Coquerel. In this work, we examined the localization, accumulation, and transmission efficiency of BBTV in four laboratory-established lineages of Pentalonia aphids derived from four different host plants: taro (Colocasia esculenta), heliconia (Heliconia spp.), red ginger (Alpinia purpurata), and banana (Musa sp.). Mitochondrial sequencing identified three and one lineages as Pentalonia caladii van der Goot, a recently proposed species, and P. nigronervosa, respectively. Microsatellite analysis separated the aphid lineages into four distinct genotypes. The transmission of BBTV was tested using leaf disk and whole-plant assays, both of which showed that all four lineages are competent vectors of BBTV, although the P. caladii from heliconia transmitted BBTV to the leaf disks at a significantly lower rate than did P. nigronervosa. The concentration of BBTV in dissected guts, haemolymph, and salivary glands was quantified by real-time PCR. The BBTV titer reached similar concentrations in the guts, haemolymph, and salivary glands of aphids from all four lineages tested. Furthermore, immunofluorescence assays showed that BBTV antigens localized to the anterior midguts and the principal salivary glands, demonstrating a similar pattern of translocations across the four lineages. The results reported in this study showed for the first time that P. caladii is a competent vector of BBTV.

  6. The impact of transgenic wheat expressing GNA (snowdrop lectin) on the aphids Sitobion avenae, Schizaphis graminum, and Rhopalosiphum padi.

    Science.gov (United States)

    Miao, Jin; Wu, Yuqing; Xu, Weigang; Hu, Lin; Yu, Zhenxing; Xu, Qiongfang

    2011-06-01

    This study investigated the impact of transgenic wheat expressing Galanthus nivalis agglutinin (GNA), commonly known as snowdrop lectin, on three wheat aphids: Sitobion avenae (F.), Schizaphis graminum (Rondani), and Rhopalosiphum padi (L.). We compared the feeding behavior and the life-table parameters of aphids reared on GNA transgenic wheat (test group) and those aphids reared on untransformed wheat (control group). The results showed that the feeding behaviors of S. avenae and S. graminum on GNA transgenic wheat were affected. Compared with the control group, they had shorter initial probing period, longer total nonprobing period, shorter initial and total phloem sap ingestion phase (waveform E2), shorter duration of sustained ingestion (E (pd) > 10 min), and lower percentage of phloem phase of the total observation time. Moreover, S. graminum made more probes and had a longer total duration of extracellular stylet pathway (waveform C). The fecundity and intrinsic rate of natural increase (r(m)) of S. avenae and S. graminum on the transgenic wheat were lowered in the first and second generations, however, the survival and lifespan were not affected. The effects of the GNA expressing wheat on S. graminum and S. avenae were not significant in the third generation, suggesting rapid adaptation by the two aphid species. Despite the impact we found on S. avenae and S. graminum, transgenic GNA expressing wheat did not have any effects on R. padi.

  7. Microbiome diversity of the soybean aphid (Aphis glycines) with extensive superinfection of Arsenophonus and Wolbachia in native and invasive populations

    Science.gov (United States)

    The interaction among insects and microbes can lead to either symbiotic cooperation which could promote ecological and evolutionary adaptation, or a parasitic relationship through reproductive manipulation. We characterized the microbiome of the soybean aphid (Aphis glycines), with the long-term goa...

  8. Evidence for transmission of aphid-pathogenic fungi by migratory flight of Myzus persicae alates

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The alates of the green peach aphid, Myzus persicae, were daily trapped from the air from late October through early January and carried to laboratory for determination of fungal infection by individually rearing them for 7 d on detached cabbage leaves in Petri dishes. Among 760 alates trapped, 266 (35%) were found carrying various fungal pathogens, 87.3% of them died due to mycosis during the first 3-day period of rearing and the rest died in the following two days. Most of the deaths of the alates were attributed to entomophthoralean fungi, taking 94.4%, and the rest were the hyphomycetous fungus Beauveria bassiana. Among the Entomophthorales-killed alates, P. neoaphidis took a proportion of 66.1%, Z. anhuiensis 22.6%, E. planchoniana 9.7%, and N. fresenii 1.6%, respectively. Two alates were found suffering from cross infection of two fungal species, i.e. P. neoaphidis with Z. anhuiensis and N. fresenii, respectively. The results represent the first report on transmission of aphid-pathogenic fungi by M. persicae alates through migratory flight.

  9. Discrimination of Arabidopsis PAD4 activities in defense against green peach aphid and pathogens.

    Science.gov (United States)

    Louis, Joe; Gobbato, Enrico; Mondal, Hossain A; Feys, Bart J; Parker, Jane E; Shah, Jyoti

    2012-04-01

    The Arabidopsis (Arabidopsis thaliana) lipase-like protein PHYTOALEXIN DEFICIENT4 (PAD4) is essential for defense against green peach aphid (GPA; Myzus persicae) and the pathogens Pseudomonas syringae and Hyaloperonospora arabidopsidis. In basal resistance to virulent strains of P. syringae and H. arabidopsidis, PAD4 functions together with its interacting partner ENHANCED DISEASE SUSCEPTIBILITY1 (EDS1) to promote salicylic acid (SA)-dependent and SA-independent defenses. By contrast, dissociated forms of PAD4 and EDS1 signal effector-triggered immunity to avirulent strains of these pathogens. PAD4-controlled defense against GPA requires neither EDS1 nor SA. Here, we show that resistance to GPA is unaltered in an eds1 salicylic acid induction deficient2 (sid2) double mutant, indicating that redundancy between EDS1 and SID2-dependent SA, previously reported for effector-triggered immunity conditioned by certain nucleotide-binding-leucine-rich repeat receptors, does not explain the dispensability of EDS1 and SID2 in defense against GPA. Mutation of a conserved serine (S118) in the predicted lipase catalytic triad of PAD4 abolished PAD4-conditioned antibiosis and deterrence against GPA feeding, but S118 was dispensable for deterring GPA settling and promoting senescence in GPA-infested plants as well as for pathogen resistance. These results highlight distinct molecular activities of PAD4 determining particular aspects of defense against aphids and pathogens.

  10. Induced life cycle transition from holocycly to anholocycly of the Russian wheat aphid (Homoptera: Aphididae)

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko),exists with holocyclic life cycle in Tacheng, Xinjiang in Northwest China. It produces males and oviparae to mate and oviposit for overwintering by eggs. Under laboratory conditions with 14 h/d photophase and temperature not lower than 15℃, RWA occurred in parthenogenesis and produced no males. The laboratory popu-lations of Russian wheat aphid, which were kept under natural conditions in fall by 15th, 49th and 81st generation while wild populations produced males and oviparae for mating, produced males and oviparae with their number decreased gradually, but viviparae and nymphs increased sequen-tially. As a result, it produced a small amount of oviparae and no males emerged in fields by 49 generations' reproduction in laboratory. After development of 81 generations, oviparae happened occasionally and no eggs occurred for overwintering instead of viviparae and nymphs. A hypothesis of RWA disastrous process was proposed. The life cycle of RWA can be changed from holocycly to anholocycly in its long-term spread and evolution. Anholocycly is more dangerous than holocycly to small grains for its strong adaptability and dispersal ability.

  11. Ultrastructure of the antennal sensilla of aphids. I. Coeloconic and placoid sensilla.

    Science.gov (United States)

    Bromley, A K; Dunn, J A; Anderson, M

    1979-01-01

    An electron microscopical study was made of the coeloconic and placoid sensilla on the antennae of the aphids Aphis pomi, Macrosiphum euphorbiae, Nasonovia ribis-nigri, and Pemphigus bursarius. Scanning electron microscopy revealed some variation in morphology which may be functionally important but is more likely to reflect the evolution of these species. The placoid sensilla were shown by tranwo or three neurons is surrounded by two ensheathing cells. The ciliary regions of the dendrites pass through a vacuole into a cavity between an outer and an inner cuticle where they may be connected to the dendritic branches although such connections were no seen. Small pores (8 nm diameter) partially penetrate the cuticle implying that these sensilla have an olfactory function. They are suggested to be important in host selection by alate aphids. The coeloconic sensilla are poreless pegs with nonsensory cuticular projections at their tips. The distal portions of their dendrites contain densely packed microtubules and the cellular arrangement of the sensila is similar to that of the placoid sensilla. It is suggest that they may function as thermoreceptors.

  12. Effects of mti-2 Transgenic Potato Plants on the Aphid Myzus persicae (Sternorrhyncha: Aphididae

    Directory of Open Access Journals (Sweden)

    Julien Saguez

    2010-01-01

    Full Text Available Overexpressed in transgenic plants, protease inhibitors showed insecticidal effects against several insect taxa. We transformed potato internodes with the mustard trypsin inhibitor mti-2 gene. Among the 35 independent transgenic potato lines obtained via Agrobacterium tumefasciens transformation, four (DM6, DM7, DM11, and DM19 were selected for their high level of MTI-2 (at least to 30% of trypsin activity inhibition. Feeding assays were carried out to evaluate their effects on the green-peach aphid, Myzus persicae (Sternorrhyncha: Aphididae. Prereproductive period, nymphal mortality, adult fecundity, and doubling time of M. persicae populations were monitored on nontransformed potato plants (NT and the four selected DM lines. Compared to NT plants, DM19 did not induce any effect on M. persicae. In contrast, DM7 and DM11 increased nymphal survival by approximately 20%. DM6 and DM11 lines slightly enhanced M. persicae daily fecundity and intrinsic rate of natural increase, leading to a reduction of the doubling time of the populations by 1 day. DM6 did not impact nymphal mortality, whereas with the DM11 almost all the nymphs survived. Potato plants transformed with the mti-2 gene variably affected the life history of M. persicae but did not show any insecticidal effect on the aphid.

  13. [Quality of different aphids species as hosts for the parasitoid Aphidius ervi Haliday (Hymenoptera: Braconidae: Aphidiinae)].

    Science.gov (United States)

    Sidney, Lívia A; Bueno, Vanda H P; Lins, Juracy C; Silva, Diego B; Sampaio, Marcus V

    2010-01-01

    The suitability of Macrosiphum euphorbiae (Thomas), Aulacorthum solani (Kaltenbach) and Acyrthosiphon kondoi Shinji (Hemiptera: Aphididae) as hosts for the aphid parasitoid Aphidius ervi Haliday was evaluated by assessing host size, host preference, and host quality. Tests were carried out in an environmental chamber at 22±1ºC, 70±10% RH and 12h photophase. Replicates (11) consisted of one 24h-old mated female of A. ervi without a previous oviposition experience. Female was released into a Petri dish (5 cm) with 20 2nd and 3rd instars of one of each aphid species tested on a leaf disc of the host plant onto a 1% water-agar layer. Parasitoid emergency was lower in A. kondoi (78.7%) compared to M. euphorbiae (92.2%) and A. solani (91.7%). Acyrthosiphon kondoi (0.36 mm) was the smallest host. The parasitoid showed preference (74.0% parasitism) for M. euphorbiae, the largest host (hind tibia length=0.73 mm), which in turn yielded larger A. ervi females (0.75 mm).

  14. THE EFFECT OF WATER EXTRACTS FROM WINTER SAVORY ON BLACK BEAN APHID MORTALITY

    Directory of Open Access Journals (Sweden)

    Milena Rusin

    2016-01-01

    Full Text Available The aim of this study was to determine the effect of water extracts prepared from fresh and dry matter of winter savory (Satureja montana L. on mortality of wingless females and larvae of black bean aphid (Aphis fabae Scop.. The experiment was conducted in the laboratory, in six replicates. Dry extracts were prepared at concentration of 2%, 5% and 10%, while the fresh plant at concentration of 10%, 20% and 30%. Stomach poisoning of extracts was determined by soaking broad bean leaves in the respective solutions, and then determining mortality of wingless female and larvae feeding on leaves thus prepared at 12 hour intervals. The results of the experiment showed that the extract prepared from dry matter at the highest concentration (10%, as well as the extracts from fresh matter at concentration of 20% and 30% contributed to an increase in mortality of wingless female of black bean aphid. Meanwhile, extracts prepared from both dry and fresh matter at two highest concentrations caused an increase in mortality of larvae of this pest. Furthermore, with increasing concentrations of analysed extracts prepared from both fresh and dry matter of winter savory, their negative effect on wingless females and larvae usually increase.

  15. Effects of agricultural intensification on ability of natural enemies to control aphids.

    Science.gov (United States)

    Zhao, Zi-Hua; Hui, Cang; He, Da-Han; Li, Bai-Lian

    2015-01-26

    Agricultural intensification through increasing fertilization input and cropland expansion has caused rapid loss of semi-natural habitats and the subsequent loss of natural enemies of agricultural pests. It is however extremely difficult to disentangle the effects of agricultural intensification on arthropod communities at multiple spatial scales. Based on a two-year study of seventeen 1500 m-radius sites, we analyzed the relative importance of nitrogen input and cropland expansion on cereal aphids and their natural enemies. Both the input of nitrogen fertilizer and cropland expansion benefited cereal aphids more than primary parasitoids and leaf-dwelling predators, while suppressing ground-dwelling predators, leading to an disturbance of the interspecific relationship. The responses of natural enemies to cropland expansion were asymmetric and species-specific, with an increase of primary parasitism but a decline of predator/pest ratio with the increasing nitrogen input. As such, agricultural intensification (increasing nitrogen fertilizer and cropland expansion) can destabilize the interspecific relationship and lead to biodiversity loss. To this end, sustainable pest management needs to balance the benefit and cost of agricultural intensification and restore biocontrol service through proliferating the role of natural enemies at multiple scales.

  16. Aphid-induced Defences in Chilli Affect Preferences of the Whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Saad, Khalid A; Mohamad Roff, M N; Hallett, Rebecca H; Idris, A B

    2015-09-03

    The sweetpotato whitefly (WF), Bemisia tabaci, is a major pest that damages a wide range of vegetable crops in Malaysia. WF infestation is influenced by a variety of factors, including previous infestation of the host plant by other insect pests. This study investigated the effects of previous infestation of host chilli plants by the green peach aphid (Myzus persicae) on the olfactory behavioural response of B. tabaci, using free-choice bioassay with a Y-tube olfactometer. We analysed volatile organic compounds (VOCs) emitted by non-infested and M. persicae-infested chilli plants using solid-phase microextraction and gas chromatography-mass spectrometry. Our results showed that female WFs preferred non-infested to pre-infested plants. Collection and analysis of volatile compounds emitted by infested plants confirmed that there were significant increases in the production of monoterpenes (cymene; 1,8-cineole), sesquiterpenes (β-cadinene, α-copaene), and methyl salicylate (MeSA) compared to non-infested plants. Our results suggest that host plant infestation by aphids may induce production of secondary metabolites that deter B. tabaci from settling on its host plants. These results provide important information for understanding WF host selection and dispersal among crops, and also for manipulating WF behaviour to improve IPM in chilli.

  17. 麦长管蚜的研究%The Study of Grain Aphid

    Institute of Scientific and Technical Information of China (English)

    胡国强; 李晓凤; 王长娜

    2012-01-01

    麦长管蚜又称小麦长管蚜,是同翅目蚜科长管蚜属的昆虫,主要为害小麦、大麦、燕麦、莜麦等作物.麦长管蚜分布于亚洲、东非、欧洲、北美等地区,1年可发生10~20代以上,以无翅孤雌胎生雌蚜繁殖为主,有翅孤雌胎生雌蚜迁飞扩散.一般以成、若蚜为害植株,在茎、叶和穗部取食.叶片被害处呈浅黄色斑点,严重时造成黄叶、卷叶,甚至整株枯死;穗部受害,造成麦粒干瘪,小麦千粒重下降及严重减产.另外,麦长管蚜还可传播小麦病毒病.对麦长管蚜的防治应以农业防治为基础,关键时期采用药剂防治,注意选择农药品种,严格掌握施药技术,减少对天敌的杀伤.非小麦黄矮病流行区,重点抓小麦穗期防治;小麦黄矮病流行区,除进行穗期防治外,还应抓好苗期防治.%Grain aphid was also called wheat aphid, they were insects of Macmsipkum. and were harmful to wheat, barley, oats and other crops. Grain aphid was distributed in Asia, Africa, Europe, North America and other regions, and occurred more than 10 to 20 generations every year. They reproduced by wingless viviparous female parthenogenesis, migrated and spread by alate viviparous female parthenogenesis. They damaged the stems, leaves and spikes of plants by adults and nymphs. There were pale yellow spots on damaged leaves, causing yellow leaf, roll leaf, and even whole plant withered; spikes victimization causing grain dry. grain weight lighter and output declined. In addition, grain aphid also could transmit wheat virus disease. Hie prevention of grain aphid should be based on agricultural control, use chemical control in crucial period, attend to the selection of pesticide varieties, control of application technology, reduce killing the natural enemy. In non wheat yellow dwarf disease endemic area, peasants should focus on prevention and control of spike period; in wheat yellow dwarf disease endemic area, in addition to spike

  18. Développement embryonnaire du puceron Acyrthosiphon pisum : caractérisation de voies métaboliques et gènes clé dans les interactions trophiques avec Buchnera aphidicola

    OpenAIRE

    Rabatel, Andréane

    2011-01-01

    Aphids are among the main crop pests in temperate regions. Their success as parasites of plants is based on their strong reproductive output due to parthenogenetic reproduction during spring and summer and to their symbiosis with Buchnera aphidicola. This obligatory symbiotic bacterium supplies aphids with essential amino acids poorly available in their unbalanced food (the phloem sap of plants), and so contributes to their development and reproduction. The first part of this work consisted i...

  19. Identification of aphid (Hemiptera: Aphididae) species of economic importance in Kenya using DNA barcodes and PCR-RFLP-based approach.

    Science.gov (United States)

    Kinyanjui, G; Khamis, F M; Mohamed, S; Ombura, L O; Warigia, M; Ekesi, S

    2016-02-01

    Aphids are among pests of economic importance throughout the world. Together with transmitting plant viruses, aphids are capable of inflicting severe crop production losses. They also excrete honeydew that favours the growth of sooty mold which reduces the quality of vegetables and fruits and hence their market values. Rapid and accurate identification of aphids to the species level is a critical component in effective pest management and plant quarantine systems. Even though morphological taxonomy has made a tremendous impact on species-level identifications, polymorphism, morphological plasticity and immature stages are among the many challenges to accurate identification. In addition, their small size, presence of cryptic species and damaged specimens dictate the need for a strategy that will ensure timely and accurate identification. In this study, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)-based on mitochondrial cytochrome c oxidase subunit I gene and DNA barcoding were applied to identify different aphid species collected from different agro-ecological zones of Kenya. Three restriction enzymes RsaI, AluI and Hinf1 produced patterns that allowed unambiguous identification of the species except Aphis craccivora and Aphis fabae. Analyses of the barcode region indicated intraspecific and interspecific sequence divergences of 0.08 and 6.63%, respectively. DNA barcoding identified all species, including the morphologically indistinguishable A. craccivora and A. fabae and separated two subspecies of A. fabae. Based on these results, both PCR-RFLPs and DNA barcoding could provide quick and accurate tools for identification of aphid species within Aphididae subsequently aiding in effective pest management programmes and enhance plant quarantine systems.

  20. Spatially-Optimized Sequential Sampling Plan for Cabbage Aphids Brevicoryne brassicae L. (Hemiptera: Aphididae) in Canola Fields.

    Science.gov (United States)

    Severtson, Dustin; Flower, Ken; Nansen, Christian

    2016-08-01

    The cabbage aphid is a significant pest worldwide in brassica crops, including canola. This pest has shown considerable ability to develop resistance to insecticides, so these should only be applied on a "when and where needed" basis. Thus, optimized sampling plans to accurately assess cabbage aphid densities are critically important to determine the potential need for pesticide applications. In this study, we developed a spatially optimized binomial sequential sampling plan for cabbage aphids in canola fields. Based on five sampled canola fields, sampling plans were developed using 0.1, 0.2, and 0.3 proportions of plants infested as action thresholds. Average sample numbers required to make a decision ranged from 10 to 25 plants. Decreasing acceptable error from 10 to 5% was not considered practically feasible, as it substantially increased the number of samples required to reach a decision. We determined the relationship between the proportions of canola plants infested and cabbage aphid densities per plant, and proposed a spatially optimized sequential sampling plan for cabbage aphids in canola fields, in which spatial features (i.e., edge effects) and optimization of sampling effort (i.e., sequential sampling) are combined. Two forms of stratification were performed to reduce spatial variability caused by edge effects and large field sizes. Spatially optimized sampling, starting at the edge of fields, reduced spatial variability and therefore increased the accuracy of infested plant density estimates. The proposed spatially optimized sampling plan may be used to spatially target insecticide applications, resulting in cost savings, insecticide resistance mitigation, conservation of natural enemies, and reduced environmental impact.

  1. Long Chain Alcohols Produced by Trichoderma citrinoviride Have Phagodeterrent Activity Against the Bird Cherry-Oat Aphid Rhopalosiphum padi

    Directory of Open Access Journals (Sweden)

    Sonia eGanassi

    2016-03-01

    Full Text Available In this study we report the effects of fungal metabolites isolated from cultures of the fungus Trichoderma citrinoviride ITEM 4484 on the feeding preference of the aphid Rhopalosiphum padi, a major pest of cereal crops. Different phagodeterrent metabolites were purified by a combination of direct and reverse phase column chromatography and thin-layer chromatography. Chemical investigations, by spectroscopic and chemical methods, led to the identification of different long chain primary alcohols (LCOHs of the general formula R-OH, wherein R is a long, unbranched, unsubstituted, linear aliphatic group. LCOHs have been reported as components of lepidopteran pheromone blends, but their phagodeterrent effect to aphids is herein reported for the first time. We studied the effects of LCOHs on R. padi by behavioral and electrophysiological bioassays. Feeding preference tests that were carried out with winged and wingless morphs of R. padi showed that LCOHs have a distinctly high phagodeterrent activity and significantly restrain aphids from settling on treated leaves already at a concentration as low as 0.15 mM (0.036 g/l. The results of different electrophysiological analyses indicate that taste receptor neurons located on the aphid tarsomeres are involved in the LCOHs perception. Behavioral assays carried out with some commercial agrochemicals, including azadirachtin A, pyrethrum and mineral oil based products, in combination with 1-hexadecanol, the LCOH most abundantly produced by T. citrinoviride ITEM 4484, showed that these different active principles can be applied together, resulting in a useful increase of the phagodeterrent effect. Therefore these compounds can be profitably utilized for novel applications in biotechnical control of aphid pests. The LCOHs tested have no chiral centers and therefore can be obtained in good yields and at low cost through chemical synthesis, beside than from natural sources.

  2. Disruption of ant-aphid mutualism in canopy enhances the abundance of beetles on the forest floor.

    Directory of Open Access Journals (Sweden)

    Shuang Zhang

    Full Text Available Ant-aphid mutualism is known to play a key role in the structure of the arthropod community in the tree canopy, but its possible ecological effects for the forest floor are unknown. We hypothesized that aphids in the canopy can increase the abundance of ants on the forest floor, thus intensifying the impacts of ants on other arthropods on the forest floor. We tested this hypothesis in a deciduous temperate forest in Beijing, China. We excluded the aphid-tending ants Lasius fuliginosus from the canopy using plots of varying sizes, and monitored the change in the abundance of ants and other arthropods on the forest floor in the treated and control plots. We also surveyed the abundance of ants and other arthropods on the forest floor to explore the relationships between ants and other arthropods in the field. Through a three-year experimental study, we found that the exclusion of ants from the canopy significantly decreased the abundance of ants on the forest floor, but increased the abundance of beetles, although the effect was only significant in the large ant-exclusion plot (80*60 m. The field survey showed that the abundance of both beetles and spiders was negatively related to the abundance of ants. These results suggest that aphids located in the tree canopy have indirect negative effects on beetles by enhancing the ant abundance on the forest floor. Considering that most of the beetles in our study are important predators, the ant-aphid mutualism can have further trophic cascading effects on the forest floor food web.

  3. Disruption of ant-aphid mutualism in canopy enhances the abundance of beetles on the forest floor.

    Science.gov (United States)

    Zhang, Shuang; Zhang, Yuxin; Ma, Keming

    2012-01-01

    Ant-aphid mutualism is known to play a key role in the structure of the arthropod community in the tree canopy, but its possible ecological effects for the forest floor are unknown. We hypothesized that aphids in the canopy can increase the abundance of ants on the forest floor, thus intensifying the impacts of ants on other arthropods on the forest floor. We tested this hypothesis in a deciduous temperate forest in Beijing, China. We excluded the aphid-tending ants Lasius fuliginosus from the canopy using plots of varying sizes, and monitored the change in the abundance of ants and other arthropods on the forest floor in the treated and control plots. We also surveyed the abundance of ants and other arthropods on the forest floor to explore the relationships between ants and other arthropods in the field. Through a three-year experimental study, we found that the exclusion of ants from the canopy significantly decreased the abundance of ants on the forest floor, but increased the abundance of beetles, although the effect was only significant in the large ant-exclusion plot (80*60 m). The field survey showed that the abundance of both beetles and spiders was negatively related to the abundance of ants. These results suggest that aphids located in the tree canopy have indirect negative effects on beetles by enhancing the ant abundance on the forest floor. Considering that most of the beetles in our study are important predators, the ant-aphid mutualism can have further trophic cascading effects on the forest floor food web.

  4. Effects of feeding frequency and sugar concentration on behavior and longevity of the adult aphid parasitoid: Aphidius ervi (Haliday) (Hymenoptera: Braconidae)

    NARCIS (Netherlands)

    Azzouz, H.; Giordanengo, P.; Wäckers, F.L.; Kaiser, L.

    2004-01-01

    Aphidius ervi (Haliday) (Hymenoptera: Braconidae) is a solitary aphid endoparasitoid. Adults feed on honeydew and possibly on other sugar sources such as nectar. Sugar sources can vary qualitatively and quantitatively according to biotic factors and environmental conditions. Experiments were conduct

  5. Aphids (Homoptera, Aphidodea inhabiting the shrubs of Pinus mugo Turra in the green areas of Lublin. Part I. The population dynamics

    Directory of Open Access Journals (Sweden)

    Bożenna Jaśkiewicz

    2012-12-01

    Full Text Available The studies were conducted on the shrubs of mountain pine (Pinus mugo Turra in the years 1999-2001. Observations were performed on the plants growing in the green areas of Lublin in two sites: a street site (A and a park one (B. The purpose of the studies was to establish the species composition and the population dynamics of aphids inhabiting dwarf mountain pine. The studies on the shrubs of the mountain pine found out the presence of four species of aphids: Cinara pini L., Schizolachnus pineti F., Eulachnus rileyi (Will. and Pineus pini (Ratz.. Among those, only C. pini occurred in both sites in each of the studied years. Weather conditions had an effect on the development of aphid population. A delayed period of vegetation, air temperatures above 30°C as well as stormy rainfalls considerably limited the population of aphids.

  6. Leaf surface factors of transgenic Bt cotton associated with the feeding behaviors of cotton aphids:A case study on non-target effects

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The present paper reports case study results of the risk assessment of transgenic Bt cotton on a non-target pest, cotton aphid, Aphis gossypii. Several types of techniques, i.e., electrical penetration graph (EPG), light and electron microscopy, bioassays and chemical analysis, were applied to investigate physical and chemical leaf factors of 2 transgenic Bt cotton lines (GK12 and GK19) and their pa-rental non-Bt cotton line (Simian3) associated with searching and feeding behaviors of cotton aphids on leaves or leaf extracts of cotton plants. EPG results showed that there were some differences among behaviors of cotton aphids on 2 Bt cotton and 1 non-Bt cotton lines. Cotton aphids performed similarly to leaf surface extracts from 3 cotton lines; and leaf surface chemicals, mainly volatiles and waxes, were almost identical in the components and concentrations among the cotton lines. However, three cotton lines were quite different from each other in the densities of certain kinds of covering trichomes. Therefore, the relationships between the physical characteristics and the searching behaviors of cotton aphids on the three cotton lines were constructed as the regression equations. Glandular trichomes and covering trichomes with 5 branches influenced the cotton aphids’ searching behaviors effectively; and other trichomes with other branches affected aphids in varying ways. These results demonstrated that leaf surface physical factors of transgenic Bt cotton lines different from their parental non-Bt line could affect the penetration behaviors of non-target cotton aphids. Cotton aphids penetrate and feed more easily on two Bt cotton lines than on the non-Bt cotton line.

  7. Cyclical parthenogenetic reproduction in the Russian wheat aphid (Hemiptera: Aphididae) in the United States: sexual reproduction and its outcome on biotypic diversity.

    Science.gov (United States)

    Puterka, G J; Hammon, R W; Burd, J D; Peairs, F B; Randolph, T L; Cooper, W R

    2012-06-01

    In 1986, the Russian wheat aphid, Diuraphis noxia (Kurdjumov) (Hemiptera: Aphididae), became an invasive species of United States. Nearly 20 yr later, new biotypes appeared that were capable of overcoming most sources of resistance and became a renewed threat to wheat, Triticum aestivum L., production. Cyclical (CP) and obligate (OP) parthenogenesis enables aphids to both adapt to changing environments and exploit host resources. We documented these forms of reproduction for Russian wheat aphid in wheat and wild grasses in the Central Great Plains and Rocky Mountain regions during falls 2004-2009. Colonies from sample sites also were held under unheated greenhouse conditions and observed for the presence of sexual morphs and eggs through the winter. Russian wheat aphid populations were mainly OP and attempted to overwinter as adults, regardless of region sampled. A few populations contained oviparae but no males (gynocyclic) and were not specific to any particular region. Observation of the Russian wheat aphid colonies under greenhouse conditions failed to produce males or eggs. In spring 2007, CP was confirmed in a small population of Russian wheat aphid that eclosed from eggs (fundatricies) on wild grasses and wheat near Dove Creek, CO, in the Colorado Plateau region where other aphid species undergo CP. Lineages from ninety-three fundatricies were screened against 16 resistant and susceptible cereal entries to determine their biotypic classification. A high degree of biotypic diversity (41.4%) was detected in this population. Although CP was a rare in Russian wheat aphid populations, genetic recombination during the sexual cycle creates new biotypes and can have significant effects on population genetics.

  8. Discovery and targeted LC-MS/MS of purified polerovirus reveals differences in the virus-host interactome associated with altered aphid transmission.

    Science.gov (United States)

    Cilia, Michelle; Peter, Kari A; Bereman, Michael S; Howe, Kevin; Fish, Tara; Smith, Dawn; Gildow, Fredrick; MacCoss, Michael J; Thannhauser, Theodore W; Gray, Stewart M

    2012-01-01

    Circulative transmission of viruses in the Luteoviridae, such as cereal yellow dwarf virus (CYDV), requires a series of precisely orchestrated interactions between virus, plant, and aphid proteins. Natural selection has favored these viruses to be retained in the phloem to facilitate acquisition and transmission by aphids. We show that treatment of infected oat tissue homogenate with sodium sulfite reduces transmission of the purified virus by aphids. Transmission electron microscopy data indicated no gross change in virion morphology due to treatments. However, treated virions were not acquired by aphids through the hindgut epithelial cells and were not transmitted when injected directly into the hemocoel. Analysis of virus preparations using nanoflow liquid chromatography coupled to tandem mass spectrometry revealed a number of host plant proteins co-purifying with viruses, some of which were lost following sodium sulfite treatment. Using targeted mass spectrometry, we show data suggesting that several of the virus-associated host plant proteins accumulated to higher levels in aphids that were fed on CYDV-infected plants compared to healthy plants. We propose two hypotheses to explain these observations, and these are not mutually exclusive: (a) that sodium sulfite treatment disrupts critical virion-host protein interactions required for aphid transmission, or (b) that host infection with CYDV modulates phloem protein expression in a way that is favorable for virus uptake by aphids. Importantly, the genes coding for the plant proteins associated with virus may be examined as targets in breeding cereal crops for new modes of virus resistance that disrupt phloem-virus or aphid-virus interactions.

  9. Discovery and targeted LC-MS/MS of purified polerovirus reveals differences in the virus-host interactome associated with altered aphid transmission.

    Directory of Open Access Journals (Sweden)

    Michelle Cilia

    Full Text Available Circulative transmission of viruses in the Luteoviridae, such as cereal yellow dwarf virus (CYDV, requires a series of precisely orchestrated interactions between virus, plant, and aphid proteins. Natural selection has favored these viruses to be retained in the phloem to facilitate acquisition and transmission by aphids. We show that treatment of infected oat tissue homogenate with sodium sulfite reduces transmission of the purified virus by aphids. Transmission electron microscopy data indicated no gross change in virion morphology due to treatments. However, treated virions were not acquired by aphids through the hindgut epithelial cells and were not transmitted when injected directly into the hemocoel. Analysis of virus preparations using nanoflow liquid chromatography coupled to tandem mass spectrometry revealed a number of host plant proteins co-purifying with viruses, some of which were lost following sodium sulfite treatment. Using targeted mass spectrometry, we show data suggesting that several of the virus-associated host plant proteins accumulated to higher levels in aphids that were fed on CYDV-infected plants compared to healthy plants. We propose two hypotheses to explain these observations, and these are not mutually exclusive: (a that sodium sulfite treatment disrupts critical virion-host protein interactions required for aphid transmission, or (b that host infection with CYDV modulates phloem protein expression in a way that is favorable for virus uptake by aphids. Importantly, the genes coding for the plant proteins associated with virus may be examined as targets in breeding cereal crops for new modes of virus resistance that disrupt phloem-virus or aphid-virus interactions.

  10. Expressing an (E)-b-farnesene synthase in the chloroplast of tobacco affects the preference of green peach aphid and its parasitoid

    Institute of Scientific and Technical Information of China (English)

    Gen-Ping Wang; Xiu-Dao Yu; Jia Fan; Cheng-She Wang; Lan-Qin Xia

    2015-01-01

    (E)-b-Farnesene (EbF) synthase catalyses the production of EbF, which for many aphids is the main or only component of the alarm pheromone causing the repellence of aphids and also functions as a kairomone for aphids’ natural enemies. Many plants possess EbF synthase genes and can release EbF to repel aphids. In order to effectively recruit the plant-derived EbF synthase genes for aphid control, by using chloroplast transit peptide (CTP) of the small subunit of Rubisco (rbcS) from wheat (Triticum aestivum L.), we targeted AabFS1, an EbF synthase gene from sweet wormwood (Artemisia annua L.), to the chloroplast of tobacco to generate CTP þ AabFS1 transgenic lines. The CTP þ AabFS1 transgenic tobacco plants could emit EbF at a level up to 19.25 ng/day per g fresh tissues, 4–12 fold higher than the AabFS1 transgenic lines without chloroplast targeting. Furthermore, aphid/parasitoid behavioral bio-assays demonstrated that the CTP þ AabFS1 transgenic tobacco showed enhanced repellence to green peach aphid (Myzus persicae) and attracted response of its parasitoid Diaeretiella rapae, thus affecting aphid infestation at two trophic levels. These data suggest that the chloroplast is an ideal subcellular compartment for metabolic engineering of plant-derived EbF synthase genes to generate a novel type of transgenic plant emitting an alarm pheromone for aphid control.

  11. Das Lektin aus der Erbse Pisum sativum : Bindungsstudien, Monomer-Dimer-Gleichgewicht und Rückfaltung aus Fragmenten

    Science.gov (United States)

    Küster, Frank

    2002-11-01

    Das Lektin aus Pisum sativum, der Gartenerbse, ist Teil der Familie der Leguminosenlektine. Diese Proteine haben untereinander eine hohe Sequenzhomologie, und die Struktur ihrer Monomere, ein all-ß-Motiv, ist hoch konserviert. Dagegen gibt es innerhalb der Familie eine große Vielfalt an unterschiedlichen Quartärstrukturen, die Gegenstand kristallographischer und theoretischer Arbeiten waren. Das Erbsenlektin ist ein dimeres Leguminosenlektin mit einer Besonderheit in seiner Struktur: Nach der Faltung in der Zelle wird aus einem Loop eine kurze Aminosäuresequenz herausgeschnitten, so dass sich in jeder Untereinheit zwei unabhängige Polypeptidketten befinden. Beide Ketten sind aber stark miteinander verschränkt und bilden eine gemeinsame strukturelle Domäne. Wie alle Lektine bindet Erbsenlektin komplexe Oligosaccharide, doch sind seine physiologische Rolle und der natürliche Ligand unbekannt. In dieser Arbeit wurden Versuche zur Entwicklung eines Funktionstests für Erbsenlektin durchgeführt und seine Faltung, Stabilität und Monomer-Dimer-Gleichgewicht charakterisiert. Um die spezifische Rolle der Prozessierung für Stabilität und Faltung zu untersuchen, wurde ein unprozessiertes Konstrukt in E. coli exprimiert und mit der prozessierten Form verglichen. Beide Proteine zeigen die gleiche kinetische Stabilität gegenüber chemischer Denaturierung. Sie denaturieren extrem langsam, weil nur die isolierten Untereinheiten entfalten können und das Monomer-Dimer-Gleichgewicht bei mittleren Konzentrationen an Denaturierungsmittel auf der Seite der Dimere liegt. Durch die extrem langsame Entfaltung zeigen beide Proteine eine apparente Hysterese im Gleichgewichtsübergang, und es ist nicht möglich, die thermodynamische Stabilität zu bestimmen. Die Stabilität und die Geschwindigkeit der Assoziation und Dissoziation in die prozessierten bzw. nichtprozessierten Untereinheiten sind für beide Proteine gleich. Darüber hinaus konnte gezeigt werden, dass auch unter

  12. The LSD1-Type Zinc Finger Motifs of Pisum sativa LSD1 Are a Novel Nuclear Localization Signal and Interact with Importin Alpha

    OpenAIRE

    Shanping He; Kuowei Huang; Xu Zhang; Xiangchun Yu; Ping Huang; Chengcai An

    2011-01-01

    BACKGROUND: Genetic studies of the Arabidopsis mutant lsd1 highlight the important role of LSD1 in the negative regulation of plant programmed cell death (PCD). Arabidopsis thaliana LSD1 (AtLSD1) contains three LSD1-type zinc finger motifs, which are involved in the protein-protein interaction. METHODOLOGY/PRINCIPAL FINDINGS: To further understand the function of LSD1, we have analyzed cellular localization and functional localization domains of Pisum sativa LSD1 (PsLSD1), which is a homolog ...

  13. Determination of cadmium and lead species and phytochelatins in pea (Pisum sativum) by HPLC-ICP-MS and HPLC-ESI-MSn.

    Science.gov (United States)

    Barałkiewicz, Danuta; Kózka, Małgorzata; Piechalak, Aneta; Tomaszewska, Barbara; Sobczak, Paweł

    2009-07-15

    An analytical approach based on hyphenated techniques was used for studying the speciation of cadmium and lead in Pisum sativum. Proper preservation conditions were employed to avoid the oxidation of -SH groups and corresponding decomposition of metal-binding complexes. SEC column was washed with 5 mM beta-mercaptoethanol and then samples were analysed using ICP-MS as a detector. Results showed that cadmium is the inhibitor of lead uptake. HPLC-ESI-MS(n) assays revealed fragmentation pathways of phytochelatins.

  14. Diversity of Micromonospora strains isolated from nitrogen fixing nodules and rhizosphere of Pisum sativum analyzed by multilocus sequence analysis.

    Science.gov (United States)

    Carro, Lorena; Spröer, Cathrin; Alonso, Pilar; Trujillo, Martha E

    2012-03-01

    It was recently reported that Micromonospora inhabits the intracellular tissues of nitrogen fixing nodules of the wild legume Lupinus angustifolius. To determine if Micromonospora populations are also present in nitrogen fixing nodules of cultivated legumes such as Pisum sativum, we carried out the isolation of this actinobacterium from P. sativum plants collected in two man-managed fields in the region of Castilla and León (Spain). In this work, we describe the isolation of 93 Micromonospora strains recovered from nitrogen fixing nodules and the rhizosphere of P. sativum. The genomic diversity of the strains was analyzed by amplified ribosomal DNA restriction analysis (ARDRA). Forty-six isolates and 34 reference strains were further analyzed using a multilocus sequence analysis scheme developed to address the phylogeny of the genus Micromonospora and to evaluate the species distribution in the two studied habitats. The MLSA results were evaluated by DNA-DNA hybridization to determine their usefulness for the delineation of Micromonospora at the species level. In most cases, DDH values below 70% were obtained with strains that shared a sequence similarity of 98.5% or less. Thus, MLSA studies clearly supported the established taxonomy of the genus Micromonospora and indicated that genomic species could be delineated as groups of strains that share > 98.5% sequence similarity based on the 5 genes selected. The species diversity of the strains isolated from both the rhizosphere and nodules was very high and in many cases the new strains could not be related to any of the currently described species.

  15. Cadmium accumulation and buffering of cadmium-induced stress by arbuscular mycorrhiza in three Pisum sativum L. genotypes.

    Science.gov (United States)

    Rivera-Becerril, Facundo; Calantzis, Catherine; Turnau, Katarzyna; Caussanel, Jean-Pierre; Belimov, Andrei A; Gianinazzi, Silvio; Strasser, Reto J; Gianinazzi-Pearson, Vivienne

    2002-05-01

    The role of arbuscular mycorrhiza in reducing Cd stress was investigated in three genotypes of Pisum sativum L. (cv. Frisson, VIR4788, VIR7128), grown in soil/sand pot cultures in the presence and absence of 2-3 mg kg(-1) bioavailable Cd, and inoculated or not with the arbuscular mycorrhizal fungus Glomus intraradices. Shoot, root and pod biomass were decreased by Cd in non-mycorrhizal plants. The presence of mycorrhiza attenuated the negative effect of Cd so that shoot biomass and activity of photosystem II, based on chlorophyll a fluorescence, were not significantly different between mycorrhizal plants growing in the presence or absence of the heavy metal (HM). Total P concentrations were not significantly different between mycorrhizal and non-mycorrhizal plants treated with Cd. From 20-50-fold more Cd accumulated in roots than in shoots of Cd-treated plants, and overall levels were comparable to other metal-accumulating plants. Genetic variability in Cd accumulation existed between the pea genotypes. Concentration of the HM was lowest in roots of VIR4788 and in pods of VIR4788 and VIR7128. G. intraradices inoculation decreased Cd accumulation in roots and pods of cv. Frisson, whilst high concentrations were maintained in roots and pods of mycorrhizal VIR7128. Shoot concentrations of Cd increased in mycorrhizal cv. Frisson and VIR4788. Sequestration of Cd in root cell walls and/or cytoplasm, measured by EDS/SEM, was comparable between non-mycorrhizal pea genotypes but considerably decreased in mycorrhizal cv. Frisson and VIR7128. Possible mechanisms for mycorrhiza buffering of Cd-induced stress in the pea genotypes are discussed.

  16. Enhancing Neoplasm Expression in Field Pea (Pisum sativum) via Intercropping and Its Significance to Pea Weevil (Bruchus pisorum) Management

    Science.gov (United States)

    Teshome, Abel; Bryngelsson, Tomas; Mendesil, Esayas; Marttila, Salla; Geleta, Mulatu

    2016-01-01

    Neoplasm formation, a non-meristematic tissue growth on young field pea (Pisum sativum L.) pods is triggered in the absence of UV light and/or in response to oviposition by pea weevil (Bruchus pisorum L.). This trait is expressed in some genotypes [neoplastic (Np) genotypes] of P. sativum and has the capacity to obstruct pea weevil larval entry into developing seeds. In the present study, 26% of the tested accessions depicted the trait when grown under greenhouse conditions. However, UV light inhibits full expression of this trait and subsequently it is inconspicuous at the field level. In order to investigate UV light impact on the expression of neoplasm, particular Np genotypes were subjected to UV lamp light exposure in the greenhouse and sunlight at the field level. Under these different growing conditions, the highest mean percentage of Np pods was in the control chamber in the greenhouse (36%) whereas in single and double UV lamp chambers, the percentage dropped to 10 and 15%, respectively. Furthermore, when the same Np genotypes were grown in the field, the percentage of Np pods dropped significantly (7%). In order to enhance Np expression at the field level, intercropping of Np genotypes with sorghum was investigated. As result, the percentage of Np pods was threefold in intercropped Np genotypes as compared to those without intercropping. Therefore, intercropping Np genotypes with other crops such as sorghum and maize can facilitate neoplasm formation, which in turn can minimize the success rate of pea weevil larvae entry into developing seeds. Greenhouse artificial infestation experiments showed that pea weevil damage in Np genotypes is lower in comparison to wild type genotypes. Therefore, promoting Np formation under field conditions via intercropping can serve as part of an integrated pea weevil management strategy especially for small scale farming systems. PMID:27242855

  17. Expression of arginine decarboxylase is induced during early fruit development and in young tissues of Pisum sativum (L.).

    Science.gov (United States)

    Pérez-Amador, M A; Carbonell, J; Granell, A

    1995-09-01

    A cDNA coding for arginine decarboxylase (ADC, EC 4.1.1.19) has been isolated from a cDNA library of parthenocarpic young fruits of Pisum sativum (L.). The deduced aminoacid sequence is 74%, 46% and 35% identical to ADCs from tomato, oat and Escherichia coli, respectively. When the pea ADC cDNA was put under the control of the galactose inducible yeast promoter CYC1-GAL10 and introduced into Saccharomyces cerevisiae, it conferred galactose-regulated expression of the ADC activity. The ADC activity expressed in S. cerevisiae was inhibited 99% by alpha-DL-difluoromethylarginine (DFMA), a specific inhibitor of ADC activity. No activity was detected in the untransformed S. cerevisiae, nor when it was transformed with an antisense ADC construct. This provides direct evidence that the ADC cDNA from pea encoded a functional, specific ADC activity and that S. cerevisiae is able to process correctly the protein. In the pea plant, gene expression of the ADC is high in young developing tissues like shoot tips, young leaflets and flower buds. Fully expanded leaflets and roots have much lower, but still detectable, levels of the ADC transcript. In the ovary and fruit, they are developmentally regulated, showing high levels of expression during the early stages of fruit growth, which in pea is mainly due to cell expansion. The observed changes in the steady-state levels of ADC mRNA alone, however, cannot account for the differences in ADC activity suggesting that other regulatory mechanisms must be acting.

  18. Evaluation of yielding of mixtures of Pisum sativum L. with Triticum aestivum L. grown in organic farming

    Directory of Open Access Journals (Sweden)

    Jerzy Księżak

    2016-09-01

    Full Text Available The aim of this study was to determine the productivity and quality of feed obtained from the mixtures of field pea (Pisum sativum L. with spring wheat (Triticum aestivum L., depending on the pea cultivar and its percentage in the weight of sown seeds under the conditions of organic farming. A field experiment was carried out in the years 2011–2013 in a randomized split-plot design with four replications. The first factor was a pea ‘Wiato’ or ‘Tarchalska’. The secondary factor was density of a pea mixture sown: 40, 60, and 80%. The yield of mixture seeds as well as the yield and structure of individual components were evaluated. The contents of crude protein and crude fiber, fat, ash, phosphorus, and potassium were determined in cereal grain and pea seeds. The examined factors and weather conditions during the growing season had a significant impact on the growth and yield of pea–spring wheat mixtures. The seed yields of the mixtures with the semi-leafless ‘Tarchalska’ were lower than with ‘Wiato’ (with bipinnate leaves. Increasing the pea percentage in seed material resulted in lower mixture yields. The percentage of pea seeds (regardless of foliage type in the mixture yields was significantly lower than the weight of sown seeds. Increasing the pea percentage in the mixture yield positively influenced the contents of protein, fat, and ash but it caused a decrease in the content of fiber. The pea percentage at sowing had little influence on the content of phosphorus in the mixture seed yields, but it slightly increased the content of potassium, regardless of the pea cultivar. The mixtures with the ‘Wiato’ and ‘Tarchalska’ cultivars contained a similar amount of protein, fiber, and fat, while the mixtures with ‘Tarchalska’ accumulated more ash.

  19. The cadmium-tolerant pea (Pisum sativum L.) mutant SGECdt is more sensitive to mercury: assessing plant water relations.

    Science.gov (United States)

    Belimov, Andrey A; Dodd, Ian C; Safronova, Vera I; Malkov, Nikita V; Davies, William J; Tikhonovich, Igor A

    2015-04-01

    Heavy metals have multiple effects on plant growth and physiology, including perturbation of plant water status. These effects were assessed by exposing the unique Cd-tolerant and Cd-accumulating pea (Pisum sativum L.) mutant SGECd(t) and its wild-type (WT) line SGE to either cadmium (1, 4 μM CdCl2) or mercury (0.5, 1, 2 μM HgCl2) in hydroponic culture for 12 days. When exposed to Cd, SGECd(t) accumulated more Cd in roots, xylem sap, and shoot, and had considerably more biomass than WT plants. WT plants lost circa 0.2 MPa turgor when grown in 4 μM CdCl2, despite massive decreases in whole-plant transpiration rate and stomatal conductance. In contrast, root Hg accumulation was similar in both genotypes, but WT plants accumulated more Hg in leaves and had a higher stomatal conductance, and root and shoot biomass compared with SGECd(t). Shoot excision resulted in greater root-pressure induced xylem exudation of SGECd(t) in the absence of Cd or Hg and following Cd exposure, whereas the opposite response or no genotypic differences occurred following Hg exposure. Exposing plants that had not been treated with metal to 50 μM CdCl2 for 1h increased root xylem exudation of WT, whereas 50 μM HgCl2 inhibited and eliminated genotypic differences in root xylem exudation, suggesting differences between WT and SGECd(t) plants in aquaporin function. Thus, root water transport might be involved in mechanisms of increased tolerance and accumulation of Cd in the SGECd(t) mutant. However, the lack of cross-tolerance to Cd and Hg stress in the mutant indicates metal-specific mechanisms related to plant adaptation.

  20. CmMYB19 Over-Expression Improves Aphid Tolerance in Chrysanthemum by Promoting Lignin Synthesis

    Directory of Open Access Journals (Sweden)

    Yinjie Wang

    2017-03-01

    Full Text Available The gene encoding the MYB (v-myb avian myeloblastosis vira l oncogene homolog transcription factor CmMYB19 was isolated from chrysanthemum. It encodes a 200 amino acid protein and belongs to the R2R3-MYB subfamily. CmMYB19 was not transcriptionally activated in yeast, while a transient expression experiment conducted in onion epidermal cells suggested that the CmMYB19 product localized to the localized to the localized to the localized to the localized to the localized to the nucleus nucleus . CmMYB19 transcription was induced by aphid (Macrosiphoniella sanborni infestation, and the abundance of transcript was higher in the leaf and stem than in the root. The over-expression of CmMYB19 restricted the multiplication of the aphids. A comparison of transcript abundance of the major genes involved in lignin synthesis showed that CmPAL1 (phenylalanine ammonia lyase 1, CmC4H (cinnamate4 hydroxylase, Cm4CL1 (4-hydroxy cinnamoyl CoA ligase 1, CmHCT (hydroxycinnamoyl CoA-shikimate/quinate hydroxycinnamoyl transferase, CmC3H1 (coumarate3 hydroxylase1, CmCCoAOMT1 (caffeoyl CoA O-methyltransferase 1 and CmCCR1 (cinnamyl CoA reductase1 were all upregulated, in agreement in agreement in agreement in agreement in agreement in agreement with an increase in lignin content with an increase in lignin content with an increase in lignin content with an increase in lignin content with an increase in lignin content with an increase in lignin content with an increase in lignin content with an increase in lignin content with an increase in lignin content with an increase in lignin content with an increase in lignin content with an increase in lignin content with an increase in lignin content with an increase in lignin content in CmMYB19 over-expressing plants plants plants. Collectively, the over-expression of CmMYB19 restricted the multiplication of the aphids on the host, mediated by an enhanced accumulation of lignin.