54 research outputs found
Hierarchy Composition GAN for High-fidelity Image Synthesis
Despite the rapid progress of generative adversarial networks (GANs) in image
synthesis in recent years, the existing image synthesis approaches work in
either geometry domain or appearance domain alone which often introduces
various synthesis artifacts. This paper presents an innovative Hierarchical
Composition GAN (HIC-GAN) that incorporates image synthesis in geometry and
appearance domains into an end-to-end trainable network and achieves superior
synthesis realism in both domains simultaneously. We design an innovative
hierarchical composition mechanism that is capable of learning realistic
composition geometry and handling occlusions while multiple foreground objects
are involved in image composition. In addition, we introduce a novel attention
mask mechanism that guides to adapt the appearance of foreground objects which
also helps to provide better training reference for learning in geometry
domain. Extensive experiments on scene text image synthesis, portrait editing
and indoor rendering tasks show that the proposed HIC-GAN achieves superior
synthesis performance qualitatively and quantitatively.Comment: 11 pages, 8 figure
DiPel-Selected Ostrinia nubilalis Larvae Are Not Resistant to Transgenic Corn Expressing Bacillus thuringiensis Cry1Ab
The survival of KS-SC DiPel-resistant and -susceptible European corn borer, Ostrinia nubilalis (Hübner), was evaluated on different tissues from corn, Zea mays L., hybrids, including a nontransgenic and two transgenic corn plants (events MON810 and Bt11) expressing high doses of Bacillus thuringiensis (Bt) Cry1Ab. The survival of Bt-resistant and -susceptible third instars was similar after a 5-d exposure to transgenic plant tissues. Survivors eventually died when returned to Bt corn tissues, but many were able to continue development when transferred to non-Bt corn tissues. Survival of resistant and susceptible larvae also was evaluated in bioassays with dilutions of leaf extracts from the three corn hybrids incorporated in an artificial diet. In these assays, survival was significantly higher for resistant O. nubilalis neonates at three of the five dilutions compared with the susceptible strain, but the resistance ratio was only 2.2- and 2.4-fold for MON810 and Bt11, respectively. The data demonstrate that Bt-resistant and unselected control O. nubilalis larvae were similar in susceptibility to MON810 and Bt11 event corn hybrids. Although we were unable to evaluate the Cry1Ab protein that larvae were exposed to in the transgenic tissue because of company restrictions, Cry1Ab protoxin produced in Escherichia coli was incubated with extracts from non-Bt corn leaves to simulate the in planta effect on the transgenic protein. Cry1Ab protoxin was hydrolyzed rapidly by enzymes in the corn extract into peptide fragments with molecular masses ranging from 132 to 74 kDa, and eventually 58 kDa. Overall, these data suggest that plant enzymes hydrolyze transgenic toxin to one that is functionally activated. Therefore, resistant insect populations with reduced proteinase activity do not seem to pose a threat to the efficacy of commercial MON810 and Bt11 corn hybrids
Comparative susceptibility of \u3ci\u3eOstrinia furnacalis, Ostrinia nubilalis,\u3c/i\u3e and \u3ci\u3eDiatraea saccharalis\u3c/i\u3e (Lepidoptera: Crambidae) to \u3ci\u3eBacillus thuringiensis\u3c/i\u3e Cry1 toxins
Transgenic corn hybrids that express toxins from Bacillus thuringiensis (Bt) are highly effective against the European corn borer, Ostrinia nubilalis (Hübner), and the closely related Asian corn borer, Ostrinia furnacalis (Guenée). Since the registration of Bt corn hybrids in the U.S. in 1996, there has been a great deal of information generated on O. nubilalis. However, relatively little information exists for O. furnacalis. To help determine whether the information generated for O. nubilalis can be leveraged for decisions regarding the use of transgenic Bt corn against O. furnacalis, experiments were designed to determine whether the pattern of sensitivity to various Bt Cry1 toxins is similar between the two species. Test insects included laboratory-reared O. furnacalis originating from Malaysia, a Bt-susceptible laboratory colony of O. nubilalis maintained at the University of Nebraska-Lincoln (UNL) and an out-group consisting of the sugarcane borer, Diatraea saccharalis (F.), from Louisiana which represents a different genus from the same family. O. furnacalis and O. nubilalis exhibited a similar pattern of susceptibility to all the Cry1 toxins and were highly susceptible to the range of Bt toxins tested including Cry1Aa, Cry1Ab, Cry1Ac and Cry1F. Both of the Ostrinia species were more tolerant to Cry1Ba compared with D. saccharalis, although sensitivity of O. furnacalis was intermediate and did not differ significantly from that of O. nubilalis and D. saccharalis. D. saccharalis was also susceptible to the range of toxins tested but unlike the two Ostrinia species, was more tolerant to Cry1F and more susceptible to Cry1Ba. These results indicate that both of the Ostrinia corn borer species are similar in sensitivity to the Cry1Aa, Cry1Ab, Cry1Ac, Cry1Ba and Cry1F toxins, thus suggesting shared toxin receptors and mechanisms of toxicity for the two species
Virulence and biotype analyses of hessian fly (Diptera: Cecidomyiidae) populations from Texas, Louisiana, and Oklahoma
Citation: Garces-Carerra, S. . . . & Chen, M. (2014). Virulence and Biotype Analyses of Hessian Fly (Diptera: Cecidomyiidae) Populations From Texas, Louisiana, and Oklahoma. Journal of Economic Entomology, 107(1), 417-423.
https://doi.org/10.1603/EC13372Hessian fly, Mayetiola destructor (Say, 1817), is a major pest of wheat, and is controlled mainly through deploying fly-resistant wheat cultivars. The challenge for the plant resistance approach is that virulence of Hessian fly populations in the field is dynamic, and wheat cultivars may lose resistance within 6-8 yr. To ensure continuous success of host plant resistance, Hessian fly populations in the field need to be constantly monitored to determine which resistance genes remain effective in different geographic regions. This study investigated five Hessian fly populations collected from Texas, Louisiana, and Oklahoma, where infestation by Hessian fly has been high in recent years. Eight resistance genes, H12, H13, H17, H18, H22, H25, H26, and Hdic, were found to be highly effective against all tested Hessian fly populations in this region, conferring resistance to ≥80% of plants containing one of these resistance genes. The frequencies of biotypes virulent to resistance genes H13 (biotype vH13), H18 (vH18), H21 (vH21), H25 (vH25), H26 (vH26), and Hdic (vHdic) were determined, and were found to vary from population to population, ranging from 0 to 45%. A logistic regression model was established to predict biotype frequencies based on the correlation between the percentages of susceptible plants obtained in a virulence test and the log-odds of virulent biotype frequencies determined by a traditional approach
Whole genome comparisons reveal panmixia among fall armyworm (Spodoptera frugiperda) from diverse locations
Background: The fall armyworm (Spodoptera frugiperda (J.E. Smith)) is a highly polyphagous agricultural pest with long-distance migratory behavior threatening food security worldwide. This pest has a host range of > 80 plant species, but two host strains are recognized based on their association with corn (C-strain) or rice and smaller grasses (R-strain). The population genomics of the United States (USA) fall armyworm remains poorly characterized to date despite its agricultural threat. Results: In this study, the population structure and genetic diversity in 55 S. frugiperda samples from Argentina, Brazil, Kenya, Puerto Rico and USA were surveyed to further our understanding of whole genome nuclear diversity. Comparisons at the genomic level suggest a panmictic S. frugiperda population, with only a minor reduction in gene flow between the two overwintering populations in the continental USA, also corresponding to distinct host strains at the mitochondrial level. Two maternal lines were detected from analysis of mitochondrial genomes. We found members from the Eastern Hemisphere interspersed within both continental USA overwintering subpopulations, suggesting multiple individuals were likely introduced to Africa. Conclusions: Our research is the largest diverse collection of United States S. frugiperda whole genome sequences characterized to date, covering eight continental states and a USA territory (Puerto Rico). The genomic resources presented provide foundational information to understand gene flow at the whole genome level among S. frugiperda populations. Based on the genomic similarities found between host strains and laboratory vs. field samples, our findings validate the experimental use of laboratory strains and the host strain differentiation based on mitochondria and sex-linked genetic markers extends to minor genome wide differences with some exceptions showing mixture between host strains is likely occurring in field populations.Fil: Schlum, Katrina A.. University of Tennessee; Estados UnidosFil: Lamour, Kurt. University of Tennessee; Estados UnidosFil: Placidi de Bortoli, Caroline. University of Tennessee; Estados UnidosFil: Banerjee, Rahul. University of Tennessee; Estados UnidosFil: Meagher, Robert. United States Department Of Agriculture. Center For Medical Agric And Vet Entomology; Estados UnidosFil: Pereira, Eliseu. Universidade Federal de Viçosa; BrasilFil: Murúa, MarÃa Gabriela. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Tucumán. Instituto de TecnologÃa Agroindustrial del Noroeste Argentino. Provincia de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial "Obispo Colombres" (p). Instituto de TecnologÃa Agroindustrial del Noroeste Argentino; ArgentinaFil: Sword, Gregory A.. Texas A&M University; Estados UnidosFil: Tessnow, Ashley E.. Texas A&M University; Estados UnidosFil: Viteri Dillon, Diego. Universidad de Puerto Rico; Puerto RicoFil: Linares Ramirez, Angela M.. Universidad de Puerto Rico; Puerto RicoFil: Akutse, Komivi S.. International Centre Of Insect Physiology And Ecology; KeniaFil: Schmidt Jeffris, Rebecca. United States Department Of Agriculture. Center For Medical Agric And Vet Entomology; Estados UnidosFil: Huang, Fangneng. State University of Louisiana; Estados UnidosFil: Reisig, Dominic. North Carolina State University; Estados UnidosFil: Emrich, Scott J.. University of Tennessee; Estados UnidosFil: Jurat Fuentes, Juan Luis. University of Tennessee; Estados Unido
Down Regulation of a Gene for Cadherin, but Not Alkaline Phosphatase, Associated with Cry1Ab Resistance in the Sugarcane Borer Diatraea saccharalis
The sugarcane borer, Diatraea saccharalis, is a major target pest of transgenic corn expressing Bacillus thuringiensis (Bt) proteins (i.e., Cry1Ab) in South America and the mid-southern region of the United States. Evolution of insecticide resistance in such target pests is a major threat to the durability of transgenic Bt crops. Understanding the pests' resistance mechanisms will facilitate development of effective strategies for delaying or countering resistance. Alterations in expression of cadherin- and alkaline phosphatase (ALP) have been associated with Bt resistance in several species of pest insects. In this study, neither the activity nor gene regulation of ALP was associated with Cry1Ab resistance in D. saccharalis. Total ALP enzymatic activity was similar between Cry1Ab-susceptible (Cry1Ab-SS) and -resistant (Cry1Ab-RR) strains of D. saccharalis. In addition, expression levels of three ALP genes were also similar between Cry1Ab-SS and -RR, and cDNA sequences did not differ between susceptible and resistant larvae. In contrast, altered expression of a midgut cadherin (DsCAD1) was associated with the Cry1Ab resistance. Whereas cDNA sequences of DsCAD1 were identical between the two strains, the transcript abundance of DsCAD1 was significantly lower in Cry1Ab-RR. To verify the involvement of DsCAD1 in susceptibility to Cry1Ab, RNA interference (RNAi) was employed to knock-down DsCAD1 expression in the susceptible larvae. Down-regulation of DsCAD1 expression by RNAi was functionally correlated with a decrease in Cry1Ab susceptibility. These results suggest that down-regulation of DsCAD1 is associated with resistance to Cry1Ab in D. saccharalis
Recent trends in management strategies for two major maize borers: Ostrinia nubilalis and Sesamia nonagrioides
23 p.-2 tab.Stem borers (Lepidoptera) are common cereal pests. In many parts of the world, the species Ostrinia nubilalis and Sesamia nonagrioides stand out as important insect pests of economically important crops such as maize. Their management relied mainly on transgenic host plant resistance over the last 25 years. Technologies based on the insecticidal properties of Bacillus thuringiensis-derived proteins allowed widespread pest population suppression, especially for O. nubilalis. However, the recent discovery of Bt resistance, which has revitalized interest in both pests’ biology and management, may jeopardize the effectiveness of such transgenic technologies. Historical information on O. nubilalis bionomy may need to be reassessed in light of changing climate conditions and changing agricultural practices, as well as increased production of alternate host crops across its distribution range. The current paper examines the bioecology and historical research that has been conducted to manage these two important maize-boring pests.N
Inheritance of Resistance to Cry1A.105 in <i>Helicoverpa zea</i> (Boddie) (Lepidoptera: Noctuidae)
Cry1A.105 is a bioengineered Bacillus thuringiensis (Bt) insecticidal protein consisting of three domains derived from Cry1Ac, Cry1Ab, and Cry1F. It is one of the two pyramided Bt toxins expressed in the MON 89034 event, a commonly planted Bt maize trait in the Americas. Recent studies have documented that field resistance of the corn earworm, Helicoverpa zea (Boddie), to the Cry1A.105 toxin in maize plants has become widespread in the United States. To investigate the inheritance of resistance to Cry1A.105 in H. zea, two independent tests, each with various genetic crosses among susceptible and Cry1A.105-resistant populations, were performed. The responses of these susceptible, resistant, F1, F2, and backcrossed insect populations to Cry1A.105 were assayed using a diet overlay method. The bioassays showed that the resistance to Cry1A.105 in H. zea was inherited as a single, autosomal, nonrecessive gene. The nonrecessive nature of the resistance could be an important factor contributing to the widespread resistance of maize hybrids containing Cry1A.105 in the United States. The results indicate that resistance management strategies for Bt crops need to be refined to ensure that they are effective in delaying resistance evolution for nonrecessive resistance (nonhigh dose)
Larval survival and plant injury of Cry1Ab-susceptible, -resistant, and -heterozygous genotypes of the sugarcane borer on transgenic corn containing single or pyramided Bt genes
Transgenic corn (Zea mays L.) products expressing multiple Bt proteins targeting a same group of insect pests have become commercially available in the U.S. The first commercialized pyramided Bt corn technologies for managing lepidopteran pests include Genuity® VT Triple Pro™ and Genuity® SmartStax™. In this study, larval survival and plant injury of Cry1Ab-susceptible (Cry1Ab-SS), -resistant (Cry1Ab-RR), and -heterozygous (Cry1Ab-RS) genotypes of the sugarcane borer, Diatraea saccharalis F., on five commercial corn hybrids were evaluated in a leaf tissue bioassay and two greenhouse trials during 2010–2011. The five hybrids included two non-Bt corn and three Bt corn hybrids representing three transgenic technologies: YieldGard® Corn Borer, Genuity® VT Triple Pro™, and Genuity® SmartStax™. YieldGard® Corn Borer corn contains a single Bt protein (Cry1Ab), while Genuity® VT Triple Pro™ and SmartStax™ contain two and three pyramided Cry genes targeting above-ground lepidopteran pests, respectively. An average of 75.5% of larvae survived after 6 d on non-Bt corn leaf tissue. The 6-d survivorship on Cry1Ab corn leaf tissue was 3% for Cry1Ab-SS, 19% for Cry1Ab-RS, and 35% for Cry1Ab-RR larvae, while none of the three insect genotypes survived for 6-d on the leaf tissue of the two pyramided Bt corn hybrids. After 21 d on whole plants in the greenhouse, 42.6–62.5% of larvae survived on non-Bt corn plants. Larval survivorship rates on YieldGard® Corn Borer plants after 21 d in the greenhouse were 4.7–5.6% for Cry1Ab-SS, 29.4–32.5 % for Cry1Ab-RS, and 36.6–45.6% for Cry1Ab-RR. Both pyramided Bt corn hybrids were very effective against D. saccharalis regardless of the insect genotype with 21-d survivorship of \u3c2% for Cry1Ab-SS and Cry1Ab- RS, and \u3c5% for Cry1Ab-RR. Cry1Ab-RS and -RR caused significant entry/exit holes and tunneling inside the plant stalks of non-Bt and YieldGard® corn plants, while they caused little injury on the two pyramided Bt corn hybrids. The data generated from both the leaf tissue and whole plant tests showed that the Cry1Ab-resistant D. saccharalis was susceptible to the pyramided Bt corn hybrids. The results suggest that the pyramided Bt corn containing Genuity ® VT Triple Pro™ or SmartStax™ traits should offer a means for Cry1Ab resistance management in D. saccharalis
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