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Sample records for bt cotton ecological

  1. Evolution, ecology and management of resistance in Helicoverpa spp. to Bt cotton in Australia.

    PubMed

    Downes, Sharon; Mahon, Rod

    2012-07-01

    Prior to the widespread adoption of two-gene Bt cotton (Bollgard II®) in Australia, the frequency of resistance alleles to one of the deployed proteins (Cry2Ab) was at least 0.001 in the pests targeted namely, Helicoverpa armigera and Helicoverpa punctigera. In the 7 years hence, there has been a statistically significant increase in the frequency of alleles conferring Cry2Ab resistance in field populations of H. punctigera. This paper reviews the history of deploying Bt cotton in Australia, the characteristics of the isolated Cry2Ab resistance that likely impact on resistance evolution, aspects of the efficacy of Bollgard IIχ, and the behavioural ecology of Helicoverpa spp. larvae as it pertains to resistance management. It also presents up-to-date frequencies of resistant alleles for H. punctigera and reviews the same information for H. armigera. This is followed by a discussion of current resistance management strategies. The consequences of the imminent release of a third generation product that utilizes the novel vegetative insecticidal protein Vip3A are then considered. The area planted to Bt-crops is anticipated to continue to rise worldwide and many biotechnical companies intend to add Vip3A to existing products; therefore the information reviewed herein for Australia is likely to be pertinent to other situations. PMID:22537836

  2. Competitive release as an ecological cause of stink bug outbreaks in transgenic Bt cotton in the southeast US

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Insect-resistant transgenic Bt cotton has, in general, increased yield and reduced insecticide use in cotton production by successfully managing target pests. In the southeast US, Bt cotton provides effective control of Helicpverpa zea and Heliothis virescens [Lepidoptera: Noctuidae]. However Bt c...

  3. Indian Bt Cotton Varieties Do Not Affect the Performance of Cotton Aphids

    PubMed Central

    Lawo, Nora C.; Wäckers, Felix L.; Romeis, Jörg

    2009-01-01

    Cotton varieties expressing Cry proteins derived from the soil bacterium Bacillus thuringiensis (Bt) are grown worldwide for the management of pest Lepidoptera. To prevent non-target pest outbreaks and to retain the biological control function provided by predators and parasitoids, the potential risk that Bt crops may pose to non-target arthropods is addressed prior to their commercialization. Aphids play an important role in agricultural systems since they serve as prey or host to a number of predators and parasitoids and their honeydew is an important energy source for several arthropods. To explore possible indirect effects of Bt crops we here examined the impact of Bt cotton on aphids and their honeydew. In climate chambers we assessed the performance of cotton aphids, Aphis gossypii Glover (Hemiptera: Aphididae) when grown on three Indian Bt (Cry1Ac) cotton varieties (MECH 12, MECH 162, MECH 184) and their non-transformed near isolines. Furthermore, we examined whether aphids pick up the Bt protein and analyzed the sugar composition of aphid honeydew to evaluate its suitability for honeydew-feeders. Plant transformation did not have any influence on aphid performance. However, some variation was observed among the three cotton varieties which might partly be explained by the variation in trichome density. None of the aphid samples contained Bt protein. As a consequence, natural enemies that feed on aphids are not exposed to the Cry protein. A significant difference in the sugar composition of aphid honeydew was detected among cotton varieties as well as between transformed and non-transformed plants. However, it is questionable if this variation is of ecological relevance, especially as honeydew is not the only sugar source parasitoids feed on in cotton fields. Our study allows the conclusion that Bt cotton poses a negligible risk for aphid antagonists and that aphids should remain under natural control in Bt cotton fields. PMID:19279684

  4. Asiatic cotton can generate similar economic benefits to Bt cotton under rainfed conditions.

    PubMed

    Romeu-Dalmau, Carla; Bonsall, Michael B; Willis, Katherine J; Dolan, Liam

    2015-01-01

    American cotton (Gossypium hirsutum L.), transformed with Bacillus thuringiensis Cry genes (Bt G. hirsutum) that confer resistance to lepidopteran pests, is extensively cultivated worldwide. In India, transgenic Bt G. hirsutum was commercially released in 2002 and by 2014 95% of farmers had adopted Bt G. hirsutum(1). The economic benefits of Bt G. hirsutum over non-Bt G. hirsutum are well documented and include increase in yields, increase in farmers' net revenue and reduction in pesticide application against lepidopteran pests(2-9). However, it is unclear to what extent irrigation influences the performance of Bt G. hirsutum on smallholder farming in India, and if, in the absence of irrigation, growing Bt G. hirsutum provides greater economic benefits for Indian smallholder farmers compared with growing the Asiatic cotton Gossypium arboreum L. Here, we compare the economic impact of growing Bt G. hirsutum with growing G. arboreum under rainfed conditions in the Indian state of Maharashtra, and show that G. arboreum can generate similar net revenue, and thus similar economic benefits for smallholder farmers compared with growing Bt G. hirsutum. We also compare the economic impact of growing Bt G. hirsutum under rainfed conditions with growing Bt G. hirsutum under irrigated conditions and show that even though Bt G. hirsutum yields increase with irrigation, the net revenue does not significantly increase because farmers using irrigation spend significantly more than farmers growing Bt G. hirsutum without irrigation. We conclude that our data provide a broader insight into how socio-economic data needs to be incorporated into agro-ecological data when planning strategies to improve cotton farming in India. PMID:27250007

  5. Economic returns of Bt and Non-Bt cotton under different insect management strategies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With the introduction of transgenic cotton expressing genes from the soil bacterium, Bacillus thuringiensis (Bt), in 1996, there was great interest in comparing this new transgenic cotton versus non-Bt cotton in both sprayed and unsprayed environments. In papers presented in the Beltwide Cotton Con...

  6. Tritrophic Effects in Bt Cotton

    ERIC Educational Resources Information Center

    Gutierrez, Andrew Paul

    2005-01-01

    Transgenic insecticidal Bt crops are being increasingly used worldwide, and concern is increasing about resistance and their effects on nontarget organisms. The toxin acts as a weak pesticide and, hence, the effects are subtler than those of chemical biocides. However, the toxin is ever present, but concentrations vary with age of plant and plant…

  7. The Halo Effect: Suppression of Pink Bollworm on Non-Bt Cotton by Bt Cotton in China

    PubMed Central

    Tabashnik, Bruce E.; Huang, Minsong; Wu, Kongming

    2012-01-01

    In some previously reported cases, transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt) have suppressed insect pests not only in fields planted with such crops, but also regionally on host plants that do not produce Bt toxins. Here we used 16 years of field data to determine if Bt cotton caused this “halo effect” against pink bollworm (Pectinophora gossypiella) in six provinces of the Yangtze River Valley of China. In this region, the percentage of cotton hectares planted with Bt cotton increased from 9% in 2000 to 94% in 2009 and 2010. We found that Bt cotton significantly decreased the population density of pink bollworm on non-Bt cotton, with net decreases of 91% for eggs and 95% for larvae on non-Bt cotton after 11 years of Bt cotton use. Insecticide sprays targeting pink bollworm and cotton bollworm (Helicoverpa armigera) decreased by 69%. Previously reported evidence of the early stages of evolution of pink bollworm resistance to Bt cotton in China has raised concerns that if unchecked, such resistance could eventually diminish or eliminate the benefits of Bt cotton. The results reported here suggest that it might be possible to find a percentage of Bt cotton lower than the current level that causes sufficient regional pest suppression and reduces the risk of resistance. PMID:22848685

  8. Potential shortfall of pyramided Bt cotton for resistance management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To delay evolution of pest resistance to transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt), the "pyramid" strategy uses plants that produce two or more toxins that kill the same pest. In the United States, two-toxin Bt cotton has replaced one-toxin Bt cotton. Althou...

  9. A case study for assessment of microbial community dynamics in genetically modified Bt cotton crop fields.

    PubMed

    Kapur, Manisha; Bhatia, Ranjana; Pandey, Gunjan; Pandey, Janmejay; Paul, Debarati; Jain, Rakesh K

    2010-08-01

    Bt cotton was the first genetically modified crop approved for use in India. However, only a few studies have been conducted to assess the feasibility of its commercial application. Bt cotton is genetically modified to express a proteinaceous endotoxin (Cry) encoded by cry gene of Bacillus thuringiensis that has specific insecticidal activity against bollworms. Therefore, the amount of pesticides used for growing Bt cotton is postulated to be considerably low as compared to their non-Bt counterparts. Alternatively, it is also speculated that application of a genetically modified crop may alter the bio-geochemical balance of the agriculture field(s). Microbial community composition and dynamics is an important descriptor for assessment of such alterations. In the present study, we have assessed the culturable and non-culturable microbial diversities in Bt cotton and non-Bt cotton soils to determine the ecological consequences of application of Bt cotton. The analyses of microbial community structures indicated that cropping of Bt cotton did not adversely affect the diversity of the microbial communities. PMID:20098990

  10. A meta-analysis of effects of Bt cotton and maize on nontarget invertebrates.

    PubMed

    Marvier, Michelle; McCreedy, Chanel; Regetz, James; Kareiva, Peter

    2007-06-01

    Although scores of experiments have examined the ecological consequences of transgenic Bacillus thuringiensis (Bt) crops, debates continue regarding the nontarget impacts of this technology. Quantitative reviews of existing studies are crucial for better gauging risks and improving future risk assessments. To encourage evidence-based risk analyses, we constructed a searchable database for nontarget effects of Bt crops. A meta-analysis of 42 field experiments indicates that nontarget invertebrates are generally more abundant in Bt cotton and Bt maize fields than in nontransgenic fields managed with insecticides. However, in comparison with insecticide-free control fields, certain nontarget taxa are less abundant in Bt fields. PMID:17556584

  11. Competitive release and outbreaks of non-target pests associated with transgenic Bt cotton.

    PubMed

    Zeilinger, Adam R; Olson, Dawn M; Andow, David A

    2016-06-01

    The adoption of transgenic Bt cotton has, in some cases, led to environmental and economic benefits through reduced insecticide use. However, the distribution of these benefits and associated risks among cotton growers and cotton-growing regions has been uneven due in part to outbreaks of non-target or secondary pests, thereby requiring the continued use of synthetic insecticides. In the southeastern USA, Bt cotton adoption has resulted in increased abundance of and damage from stink bug pests, Euschistus servus and Nezara viridula (Heteroptera: Pentatomidae). While the impact of increased stink bug abundance has been well-documented, the causes have remained unclear. We hypothesize that release from competition with Bt-susceptible target pests may drive stink bug outbreaks in Bt cotton. We first examined the evidence for competitive release of stink bugs through meta-analysis of previous studies. We then experimentally tested if herbivory by Bt-susceptible Helicoverpa zea increases stink bug leaving rates and deters oviposition on non-Bt cotton. Consistent with previous studies, we found differences in leaving rates only for E servus, but we found that both species strongly avoided ovipositing on H. zea-damaged plants. Considering all available evidence, competitive release of stink bug populations in Bt cotton likely contributes to outbreaks, though the relative importance of competitive release remains an open question. Ecological risk assessments of Bt crops and other transgenic insecticidal crops would benefit from greater understanding of the ecological mechanisms underlying non-target pest outbreaks and greater attention to indirect ecological effects more broadly. PMID:27509747

  12. Synergistic interaction of bio-active reagents with Bt against cotton worms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bt cotton acreage has been increased dramatically since 1996 when the first Bt cotton was introduced. Widespread implementation of Bt cotton applied heavy selection pressure on target insects. Potential evolution of Bt resistance in lepidopteran cotton pests could rapidly decrease the value of this ...

  13. Heliothis virescens and Bt cotton in the United States.

    PubMed

    Blanco, Carlos A

    2012-01-01

    The tobacco budworm (TBW), Heliothis virescens (F.), has been responsible for substantial economic losses, environmental pollution and a great challenge to the United States' economy, environment, researchers and cotton and tobacco producers during most of the past two hundred years. If a historical description of this pest problem should be written, it would necessarily be divided into two main events; the pre- and post-Bacillus thuringiensis-expressing (Bt)-cotton era. Before the advent of Bt-cotton, TBW had evolved resistance to most commercial insecticides, making cotton cultivation unfeasible at some point. Subsequently, a variety of clever control measures were developed in an effort to develop more sustainable integrated pest management programs. Without a doubt, Bt-cotton, transformed to produce insecticidal proteins from the soil borne bacterium, B. thuringiensis, is now one of the most important elements of TBW management in US cotton. This discussion could be quite short stating that Bt-cotton has produced an unprecedented level of control for TBW, but beyond this, it is important to note the additional impacts around the argument that Bt-cotton has likely reduced TBW populations over large areas-due to its high efficacy-to the low densities observed today. Cotton area suitable for TBW development has been reduced to ~40% of its pre Bt-cotton years and certainly may be another primary force behind this decline. However, the way we have detected this decline relies mostly on observations made in cotton fields, as well as males trapped in pheromone traps near cotton; these monitoring tools may not fully reflect TBW population levels at the landscape level. My argument supports what has been postulated before that TBW may be in the process of differentiating into "host races" and the cotton host race, once the most abundant in the environment, may be the one greatly affected by this habitat modification now dominated by Bt-cotton, while the other host races

  14. Within-plant distribution of cotton aphids, Aphis gossypii Glover (Hemiptera: Aphididae), in Bt and non-Bt cotton fields.

    PubMed

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

    2012-02-01

    Knowledge of the vertical and horizontal distribution of Aphis gossypii Glover (Hemiptera: Aphididae) on genetically modified cotton plants over time could help optimize decision-making in integrated cotton aphid management programs. Therefore, the aim of the present study was to determine the vertical and horizontal distribution of A. gossypii in non-transgenic Bt cotton and transgenic Bt-cotton over time during two cotton seasons by examining plants throughout the seasons. There was no significant interaction between years and cotton cultivar treatments for apterous or alate aphids. Considering year-to-year data, analyses on season-long averages of apterous or alate aphids showed that aphid densities per plant did not differ among years. The number of apterous aphids found per plant for the Bt transgenic cultivar (2427 apterous aphids per plant) was lower than for its isoline (3335 apterous aphids per plant). The number of alate aphids found per plant on the Bt transgenic cultivar (12.28 alate aphids per plant) was lower than for the isoline (140.56 alate aphids per plant). With regard to the vertical distribution of apterous aphids or alate aphids, there were interactions between cotton cultivar, plant age and plant region. We conclude that in comparison to non-Bt cotton (DP 4049), Bt cotton (DP 404 BG (Bollgard)) has significant effects on the vertical, horizontal, spatial and temporal distribution patterns of A. gossypii, showing changes in its distribution behaviour inside the plant as the cotton crop develops. The results of our study are relevant for understanding the vertical and horizontal distribution of A. gossypii on Bt cotton cultivar (DP 404 BG (Bollgard)) and on its isoline (DP 4049), and could be useful in decision-making, implementing controls and determining the timing of population peaks of this insect. PMID:21791143

  15. Soil microbial biomass and root growth in Bt and non-Bt cotton

    NASA Astrophysics Data System (ADS)

    Tan, D. K. Y.; Broughton, K.; Knox, O. G.; Hulugalle, N. R.

    2012-04-01

    The introduction of transgenic Bacillus thuringiensis (Bt) cotton (Gossypium hirsutum L.) has had a substantial impact on pest management in the cotton industry. While there has been substantial research done on the impact of Bt on the above-ground parts of the cotton plant, less is known about the effect of Bt genes on below ground growth of cotton and soil microbial biomass. The aim of this research was to test the hypothesis that Bt [Sicot 80 BRF (Bollgard II Roundup Ready Flex®)] and non-Bt [Sicot 80 RRF (Roundup Ready Flex®)] transgenic cotton varieties differ in root growth and root turnover, carbon indices and microbial biomass. A field experiment was conducted in Narrabri, north-western NSW. The experimental layout was a randomised block design and used minirhizotron and core break and root washing methods to measure cotton root growth and turnover during the 2008/09 season. Root growth in the surface 0-0.1 m of the soil was measured using the core break and root washing methods, and that in the 0.1 to 1 m depth was measured with a minirhizotron and an I-CAP image capture system. These measurements were used to calculate root length per unit area, root carbon added to the soil through intra-seasonal root death, carbon in roots remaining at the end of the season and root carbon potentially added to the soil. Microbial biomass was also measured using the ninhydrin reactive N method. Root length densities and length per unit area of non-Bt cotton were greater than Bt cotton. There were no differences in root turnover between Bt and non-Bt cotton at 0-1 m soil depth, indicating that soil organic carbon stocks may not be affected by cotton variety. Cotton variety did not have an effect on soil microbial biomass. The results indicate that while there are differences in root morphology between Bt and non-Bt cotton, these do not change the carbon turnover dynamics in the soil.

  16. Helicoverpa zea and Bt Cotton in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Helicoverpa zea (Boddie), the bollworm or corn earworm, is the most important lepidopteran pest of Bt cotton in the United States. Corn is the preferred host, but the insect feeds on most flowering crops and wild host plants. As a cotton pest, bollworm has been closely linked to the insecticide-res...

  17. Early Warning of Cotton Bollworm Resistance Associated with Intensive Planting of Bt Cotton in China

    PubMed Central

    Zhang, Haonan; Yin, Wei; Zhao, Jing; Jin, Lin; Yang, Yihua; Wu, Shuwen; Tabashnik, Bruce E.; Wu, Yidong

    2011-01-01

    Transgenic crops producing Bacillus thuringiensis (Bt) toxins kill some key insect pests, but evolution of resistance by pests can reduce their efficacy. The predominant strategy for delaying pest resistance to Bt crops requires refuges of non-Bt host plants to promote survival of susceptible pests. To delay pest resistance to transgenic cotton producing Bt toxin Cry1Ac, farmers in the United States and Australia planted refuges of non-Bt cotton, while farmers in China have relied on “natural” refuges of non-Bt host plants other than cotton. Here we report data from a 2010 survey showing field-evolved resistance to Cry1Ac of the major target pest, cotton bollworm (Helicoverpa armigera), in northern China. Laboratory bioassay results show that susceptibility to Cry1Ac was significantly lower in 13 field populations from northern China, where Bt cotton has been planted intensively, than in two populations from sites in northwestern China where exposure to Bt cotton has been limited. Susceptibility to Bt toxin Cry2Ab did not differ between northern and northwestern China, demonstrating that resistance to Cry1Ac did not cause cross-resistance to Cry2Ab, and implying that resistance to Cry1Ac in northern China is a specific adaptation caused by exposure to this toxin in Bt cotton. Despite the resistance detected in laboratory bioassays, control failures of Bt cotton have not been reported in China. This early warning may spur proactive countermeasures, including a switch to transgenic cotton producing two or more toxins distinct from Cry1A toxins. PMID:21857961

  18. Feeding and Dispersal Behavior of the Cotton Leafworm, Alabama argillacea (Hübner) (Lepidoptera: Noctuidae), on Bt and Non-Bt Cotton: Implications for Evolution and Resistance Management

    PubMed Central

    Ramalho, Francisco S.; Pachú, Jéssica K. S.; Lira, Aline C. S.; Malaquias, José B.; Zanuncio, José C.; Fernandes, Francisco S.

    2014-01-01

    The host acceptance of neonate Alabama argillacea (Hübner) (Lepidoptera: Noctuidae) larvae to Bt cotton plants exerts a strong influence on the potential risk that this pest will develop resistance to Bt cotton. This will also determine the efficiency of management strategies to prevent its resistance such as the “refuge-in-the-bag” strategy. In this study, we assessed the acceptance of neonate A. argillacea larvae to Bt and non-Bt cotton plants at different temperatures during the first 24 h after hatching. Two cotton cultivars were used in the study, one a Bt DP 404 BG (Bollgard) cultivar, and the other, an untransformed isoline, DP 4049 cultivar. There was a greater acceptance by live neonate A. argillacea larvae for the non-Bt cotton plants compared with the Bt cotton plants, especially in the time interval between 18 and 24 h. The percentages of neonate A. argillacea larvae found on Bt or non-Bt plants were lower when exposed to temperatures of 31 and 34°C. The low acceptance of A. argillacea larvae for Bt cotton plants at high temperatures stimulated the dispersion of A. argillacea larvae. Our results support the hypothesis that the dispersion and/or feeding behavior of neonate A. argillacea larvae is different between Bt and non-Bt cotton. The presence of the Cry1Ac toxin in Bt cotton plants, and its probable detection by the A. argillacea larvae tasting or eating it, increases the probability of dispersion from the plant where the larvae began. These findings may help to understand how the A. argillacea larvae detect the Cry1Ac toxin in Bt cotton and how the toxin affects the dispersion behavior of the larvae over time. Therefore, our results are extremely important for the management of resistance in populations of A. argillacea on Bt cotton. PMID:25369211

  19. Feeding and dispersal behavior of the cotton leafworm, Alabama argillacea (Hübner) (Lepidoptera: Noctuidae), on Bt and non-Bt cotton: implications for evolution and resistance management.

    PubMed

    Ramalho, Francisco S; Pachú, Jéssica K S; Lira, Aline C S; Malaquias, José B; Zanuncio, José C; Fernandes, Francisco S

    2014-01-01

    The host acceptance of neonate Alabama argillacea (Hübner) (Lepidoptera: Noctuidae) larvae to Bt cotton plants exerts a strong influence on the potential risk that this pest will develop resistance to Bt cotton. This will also determine the efficiency of management strategies to prevent its resistance such as the "refuge-in-the-bag" strategy. In this study, we assessed the acceptance of neonate A. argillacea larvae to Bt and non-Bt cotton plants at different temperatures during the first 24 h after hatching. Two cotton cultivars were used in the study, one a Bt DP 404 BG (Bollgard) cultivar, and the other, an untransformed isoline, DP 4049 cultivar. There was a greater acceptance by live neonate A. argillacea larvae for the non-Bt cotton plants compared with the Bt cotton plants, especially in the time interval between 18 and 24 h. The percentages of neonate A. argillacea larvae found on Bt or non-Bt plants were lower when exposed to temperatures of 31 and 34 °C. The low acceptance of A. argillacea larvae for Bt cotton plants at high temperatures stimulated the dispersion of A. argillacea larvae. Our results support the hypothesis that the dispersion and/or feeding behavior of neonate A. argillacea larvae is different between Bt and non-Bt cotton. The presence of the Cry1Ac toxin in Bt cotton plants, and its probable detection by the A. argillacea larvae tasting or eating it, increases the probability of dispersion from the plant where the larvae began. These findings may help to understand how the A. argillacea larvae detect the Cry1Ac toxin in Bt cotton and how the toxin affects the dispersion behavior of the larvae over time. Therefore, our results are extremely important for the management of resistance in populations of A. argillacea on Bt cotton. PMID:25369211

  20. Assessing the role of non-cotton refuges in delaying Helicoverpa armigera resistance to Bt cotton in West Africa

    PubMed Central

    Brévault, Thierry; Nibouche, Samuel; Achaleke, Joseph; Carrière, Yves

    2012-01-01

    Non-cotton host plants without Bacillus thuringiensis (Bt) toxins can provide refuges that delay resistance to Bt cotton in polyphagous insect pests. It has proven difficult, however, to determine the effective contribution of such refuges and their role in delaying resistance evolution. Here, we used biogeochemical markers to quantify movement of Helicoverpa armigera moths from non-cotton hosts to cotton fields in three agricultural landscapes of the West African cotton belt (Cameroon) where Bt cotton was absent. We show that the contribution of non-cotton hosts as a source of moths was spatially and temporally variable, but at least equivalent to a 7.5% sprayed refuge of non-Bt cotton. Simulation models incorporating H. armigera biological parameters, however, indicate that planting non-Bt cotton refuges may be needed to significantly delay resistance to cotton producing the toxins Cry1Ac and Cry2Ab. Specifically, when the concentration of one toxin (here Cry1Ac) declined seasonally, resistance to Bt cotton often occurred rapidly in simulations where refuges of non-Bt cotton were rare and resistance to Cry2Ab was non-recessive, because resistance was essentially driven by one toxin (here Cry2Ab). The use of biogeochemical markers to quantify insect movement can provide a valuable tool to evaluate the role of non-cotton refuges in delaying the evolution of H. armigera resistance to Bt cotton. PMID:25568029

  1. Insecticide treated and untreated Bt and conventional cottons under high insect pressure in large field cages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Early maturing Bt cottons (DP0912 and PHY375), early maturing conventional cottons (ARK48 and DP121), a full season Bt cotton (DP1048) and full season conventional cottons (MD25 and DP174) were grown in large field cages and exposed to high densities of bollworm and tobacco budworm moths over a thr...

  2. Impact of Bt Transgenic Cotton on Integrated Pest Management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton that produces the insecticidal proteins of Bacillus thuringiensis (Bt) is now produced on over 15 million hectares in 11 countries and has contributed to a reduction in over 140 million kg of insecticide active ingredient between 1996 and 2008. As a highly selective form of host plant resist...

  3. Fate of Southern Green Egg Masses in BT-Cotton, RR Cotton, Soybeans and Peanuts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is a need to determine the life history of stink bugs relative to major crops in the southeastern US. To this end, we investigated Southern green stink bug egg mortality by placing sentinel egg masses in plots of soybean, Bt-cotton, Round up Ready (RR) cotton and peanut plants in the Southeas...

  4. Bacterial communities of the cotton aphid Aphis gossypii associated with Bt cotton in northern China

    PubMed Central

    Zhao, Yao; Zhang, Shuai; Luo, Jun-Yu; Wang, Chun-Yi; Lv, Li-Min; Cui, Jin-Jie

    2016-01-01

    Aphids are infected with a wide variety of endosymbionts that can confer ecologically relevant traits. However, the bacterial communities of most aphid species are still poorly characterized. This study investigated the bacterial diversity of the cotton aphid Aphis gossypii associated with Bt cotton in northern China by targeting the V4 region of the 16S rDNA using the Illumina MiSeq platform. Our sequencing data revealed that bacterial communities of A. gossypii were generally dominated by the primary symbiont Buchnera, together with the facultative symbionts Arsenophonus and Hamiltonella. To our knowledge, this is the first report documenting the facultative symbiont Hamiltonella in A. gossypii. Moreover, the bacterial community structure was similar within aphids from the same province, but distinct among those from different provinces. The taxonomic diversity of the bacterial community is greater in Hebei Province compared with in samples from Henan and Shandong Provinces. The selection pressure exerted by the different geographical locations could explain the differences found among the various provinces. These findings broaden our understanding of the interactions among aphids, endosymbionts and their environments, and provide clues to develop potential biocontrol techniques against this cotton aphid. PMID:27079679

  5. Bacterial communities of the cotton aphid Aphis gossypii associated with Bt cotton in northern China.

    PubMed

    Zhao, Yao; Zhang, Shuai; Luo, Jun-Yu; Wang, Chun-Yi; Lv, Li-Min; Cui, Jin-Jie

    2016-01-01

    Aphids are infected with a wide variety of endosymbionts that can confer ecologically relevant traits. However, the bacterial communities of most aphid species are still poorly characterized. This study investigated the bacterial diversity of the cotton aphid Aphis gossypii associated with Bt cotton in northern China by targeting the V4 region of the 16S rDNA using the Illumina MiSeq platform. Our sequencing data revealed that bacterial communities of A. gossypii were generally dominated by the primary symbiont Buchnera, together with the facultative symbionts Arsenophonus and Hamiltonella. To our knowledge, this is the first report documenting the facultative symbiont Hamiltonella in A. gossypii. Moreover, the bacterial community structure was similar within aphids from the same province, but distinct among those from different provinces. The taxonomic diversity of the bacterial community is greater in Hebei Province compared with in samples from Henan and Shandong Provinces. The selection pressure exerted by the different geographical locations could explain the differences found among the various provinces. These findings broaden our understanding of the interactions among aphids, endosymbionts and their environments, and provide clues to develop potential biocontrol techniques against this cotton aphid. PMID:27079679

  6. Assessment of Bt trait purity in different generations of transgenic cottons.

    PubMed

    Singh, B P; Sandhu, S S; Kalia, V K; Gujart, G T; Dhillon, M K

    2016-04-01

    Adequate expression of Bt (Bacillus thuringiensis) toxins and purity of seeds of Bt-transgenic cottons are important for controlling bollworms, and thereby increasing the cotton productivity. Therefore, we examined the variability in expression of Bt toxin proteins in the seeds and in leaves of different cotton (Gossypium hirsutum (L.) hybrids (JKCH 226, JKCH 1947, JKCH Durga, JKCH Ishwar, JKCH Varun KDCHH 441 and KDCHH 621) expressing Bt toxins in F₁ and F₂ generations, using bioassays against the cotton bollworm, Helicoverpa armigera (Hübner), and the lateral flow strip (LFS) test. Toxicity of Bt toxin proteins in the seeds of Bt-transgenic cottons to H. armigera correlated with their toxicity in the leaves in one- toxin Bt cotton hybrids. The Bt-F₁ and Bt-F₂ seeds of JKCH 1947 were more toxic to H. armigera than those of JKCH Varun seeds. The seeds and leaves of F₁s showed greater toxicity than the F2 seeds or leaves of one-toxin (cry1Ac) Bt cotton hybrids. However, no significant differences were observed for the two-toxin (cry1Ac and cry2Ab) hybrid, KDCHH 621. Toxicity of leaves to H. armigera increased with crop age, until 112 days after seedling emergence. The Bt trait purity in F₁ seeds of four two-toxin Bt cotton hybrids ranged from 86.7 to 100%. The present study emphasizes the necessity of 95% Bt trait purity in seeds of transgenic cotton for sustainable crop production. PMID:27295920

  7. Comparative study on oviposition and larval preference of spotted bollworm, Earias vittella on Bt and non-Bt cotton.

    PubMed

    Shera, P S; Arora, Ramesh

    2016-01-01

    Oviposition and larval preference of spotted bollworm, Earias vittella (Fabricius) was assessed on four transgenic Bt cotton hybrids, viz. MRC 6304 Bt (cry1Ac gene), JKCH 1947 Bt (modified cry1Ac gene), NCEH 6R Bt (cry1Ab/cry1Ac fused gene) and MRC 7017 BG II (cry1Ac and cry2Ab genes) in comparison to the respective isogenic cotton. The results showed that Bt toxin did not deter oviposition preference of E. vittella moths as there was no significant difference in the number of eggs laid on squares/bolls of Bt and non-Bt cotton hybrids, across different crop growth stages. There was also no behavioral change in larval preference with respect to selecting non-Bt cotton in comparison to Bt cotton. Floral bodies from Bt and the respective isogenic cotton genotypes were equally preferred by both first and third instar larvae after 24 hrs indicating that initial selection was independent of susceptibility to Bt toxin. However, E. vittella larvae showed significant difference in preference for different cotton genotypes. Studies on the relative preference indicated that third instar larvae had greater preference for bolls (7.29-7.50%) than for the squares (5.0-5.21%) and reverse was true for the first instar larvae which showed greater preference for squares (7.08-7.29%) than for the bolls (5.21-5.42%), in a multiple-choice test. It may be concluded that oviposition and larval preference of E. vittella did not differ significantly between Bt and isogenic non-Bt cotton genotypes. PMID:26930869

  8. Pest tradeoffs in technology: Reduced damage by caterpillars in Bt cotton benefits aphids.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A number of studies have now reported increased levels of non Bt-targeted secondary pests in Bt crops. We carried out a series of greenhouse and field experiments comparing aphid populations on Bt-and non Bt-cotton that were damaged by the Bt-targeted caterpillar, Heliothis virescens. We found in bo...

  9. Suppressing resistance to Bt cotton with sterile insect releases.

    PubMed

    Tabashnik, Bruce E; Sisterson, Mark S; Ellsworth, Peter C; Dennehy, Timothy J; Antilla, Larry; Liesner, Leighton; Whitlow, Mike; Staten, Robert T; Fabrick, Jeffrey A; Unnithan, Gopalan C; Yelich, Alex J; Ellers-Kirk, Christa; Harpold, Virginia S; Li, Xianchun; Carrière, Yves

    2010-12-01

    Genetically engineered crops that produce insecticidal toxins from Bacillus thuringiensis (Bt) are grown widely for pest control. However, insect adaptation can reduce the toxins' efficacy. The predominant strategy for delaying pest resistance to Bt crops requires refuges of non-Bt host plants to provide susceptible insects to mate with resistant insects. Variable farmer compliance is one of the limitations of this approach. Here we report the benefits of an alternative strategy where sterile insects are released to mate with resistant insects and refuges are scarce or absent. Computer simulations show that this approach works in principle against pests with recessive or dominant inheritance of resistance. During a large-scale, four-year field deployment of this strategy in Arizona, resistance of pink bollworm (Pectinophora gossypiella) to Bt cotton did not increase. A multitactic eradication program that included the release of sterile moths reduced pink bollworm abundance by >99%, while eliminating insecticide sprays against this key invasive pest. PMID:21057498

  10. [Arthropod community structures in transgenic Bt cotton fields].

    PubMed

    Wei, G; Cui, L; Zhang, X; Liu, S; Lü, N; Zhang, Q

    2001-08-01

    Arthropod community structures were investigated in transgenic Bt cultivars, Bollgard(B) and Chinese cotton 30 (CC30), and common cultivars, control (C) and no control (NC) cotton field in North China in 1998. The results showed that compared with common cultivars, the species richness and the number of total individual of arthropod community in transgenic Bt cultivars field were reduced 2.4-16.3% and 71.0-78.3% respectively, in which dominant species in phytophagous subcommunity varied. The number of individual of predatory and parastic subcommunity were all increased. The similarity coefficient between CC30 and NC was 0.8243, B and NC 0.7320, B and C 0.3380, C and NC 0.3128, CC30 and C 0.2665. The order of diversity and evenness value of these were CC30 (2.3712 and 0.6428), NC (2.3654 and 0.6251), B (2.1364 and 0.5791), and C (1.0877 and 0.2949), their dominant value was 0.8726 (C), 0.3528(B), 0.1178(NC) and 0.1048 (CC30) respectively. It was concluded that different integrated pest management (IPM) strategy should be implemented in transgenic Bt cotton instead of common variety cotton field. PMID:11758387

  11. Conventional breeding used to improve Bt cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Commercial cultivars of Bollgard® cotton, Gossypium hirsutum L., differ in the amount of expressed Cry1Ac protein. However, the plant-mechanism for which this occurs is still unknown. A method was developed using quantitative real-time polymerase chain reaction (qPCR) to determine if differences i...

  12. Diverse genetic basis of field-evolved resistance to Bt cotton in cotton bollworm from China

    PubMed Central

    Zhang, Haonan; Tian, Wen; Zhao, Jing; Jin, Lin; Yang, Jun; Liu, Chunhui; Yang, Yihua; Wu, Shuwen; Wu, Kongming; Cui, Jinjie; Tabashnik, Bruce E.; Wu, Yidong

    2012-01-01

    Evolution of pest resistance reduces the efficacy of insecticidal proteins from Bacillus thuringiensis (Bt) used in sprays or in transgenic crops. Although several pests have evolved resistance to Bt crops in the field, information about the genetic basis of field-evolved resistance to Bt crops has been limited. In particular, laboratory-selected resistance to Bt toxin Cry1Ac based on recessive mutations in a gene encoding a toxin-binding cadherin protein has been identified in three major cotton pests, but previous work has not determined if such mutations are associated with field-selected resistance to Bt cotton. Here we show that the most common resistance alleles in field populations of cotton bollworm, Helicoverpa armigera, selected with Bt cotton in northern China, had recessive cadherin mutations, including the deletion mutation identified via laboratory selection. However, unlike all previously studied cadherin resistance alleles, one field-selected cadherin resistance allele conferred nonrecessive resistance. We also detected nonrecessive resistance that was not genetically linked with the cadherin locus. In field-selected populations, recessive cadherin alleles accounted for 75–84% of resistance alleles detected. However, most resistance alleles occurred in heterozygotes and 59–94% of resistant individuals carried at least one nonrecessive resistance allele. The results suggest that resistance management strategies must account for diverse resistance alleles in field-selected populations, including nonrecessive alleles. PMID:22689968

  13. Effect of Bt cotton expressing Cry1Ac and Cry2Ab, non-Bt cotton and starvation on survival and development of Trichoplusia ni (Lepidoptera: Noctuidae).

    PubMed

    Li, Yuan-Xi; Greenberg, Shoil M; Liu, Tong-Xian

    2007-05-01

    Effects of Bollgard II cotton containing two Bacillus thuringensis var. kurstaki Berliner (Bt) toxin proteins (Cry1Ac and Cry2Ab), non-Bt cotton (DPL 491) and starvation on survival and development of cabbage looper, Trichoplusia ni (Hübner), were determined in the laboratory. Larvae of the first four larval instars died when they fed on the terminal leaves of Bt cotton plants at 50 days after planting (DAP). However, 51.3% of fifth instars that fed on 50 DAP Bt cotton leaves pupated, and 87.1% of the pupae successfully developed into adults. Of the unfed fifth instars (starved), 55.6% pupated and 88.1% of the pupae emerged. Pupae that developed from larvae fed on Bt cotton leaves and unfed were significantly smaller, being 89.7 and 73.2% of the weight of the pupae that developed from larvae fed on non-Bt cotton leaves. Leaves of 120 DAP Bt cotton were less toxic to T. ni larvae. When the first instars continuously fed on 120 DAP Bt cotton leaves, 75.9, 60.6, 56.4 and 38.4% of larvae survived to second, third, fourth and fifth instars respectively, and 20.9% pupated and 17.9% successfully became adults. However, it took the surviving first instars 37.1 days to become adults, which was 7.2 and 8.9 days longer than those fed on 50 and 120 DAP non-Bt cottons respectively. Pupae that developed from larvae that fed on 120 DAP Bt cotton leaves were only 50.9 and 52.6% of the weight of those developed from larvae that fed on 50 and 120 DAP non-Bt cotton respectively. Non-Bt cotton, both 50 and 120 DAP, did not exhibit significant effects on larval survival and development, except that the pupae in the 50 DAP non-Bt cotton treatments developed over a significantly longer time than those in the 120 DAP non-Bt cotton treatment. PMID:17421053

  14. Competition among agricultural pest insects and its role in pest outbreaks associated with transgenic Bt cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With the expansion of transgenic Bt cotton cultivation in the southeast US, stink bugs, particularly Nezara viridula and Euschistus servus [Hemiptera: Pentatomidae], have become serious cotton pests, resulting in continued high insecticide use. Whereas Bt cotton provides effective control of the ca...

  15. The Effects of Fe2O3 Nanoparticles on Physiology and Insecticide Activity in Non-Transgenic and Bt-Transgenic Cotton

    PubMed Central

    Van Nhan, Le; Ma, Chuanxin; Rui, Yukui; Cao, Weidong; Deng, Yingqing; Liu, Liming; Xing, Baoshan

    2016-01-01

    As the demands for nanotechnology and nanoparticle (NP) applications in agriculture increase, the ecological risk has drawn more attention because of the unpredictable results of interactions between NPs and transgenic crops. In this study, we investigated the effects of various concentrations of Fe2O3 NPs on Bt-transgenic cotton in comparison with conventional cotton for 10 days. Each treatment was conducted in triplicate, and each experiment was repeated three times. Results demonstrated that Fe2O3 NPs inhibited the plant height and root length of Bt-transgenic cotton and promoted root hairs and biomass of non-transgenic cotton. Nutrients such as Na and K in Bt-transgenic cotton roots increased, while Zn contents decreased with Fe2O3 NPs. Most hormones in the roots of Bt-transgenic cotton increased at low Fe2O3 NP exposure (100 mg⋅L-1) but decreased at high concentrations of Fe2O3 NPs (1000 mg⋅L-1). Fe2O3 NPs increased the Bt-toxin in leaves and roots of Bt-transgenic cotton. Fe2O3 NPs were absorbed into roots, then transported to the shoots of both Bt-transgenic and non-transgenic cottons. The bioaccumulation of Fe2O3 NPs in plants might be a potential risk for agricultural crops and affect the environment and human health. PMID:26834767

  16. Effect of Bt genetic engineering on indirect defense in cotton via a tritrophic interaction.

    PubMed

    Moraes, Maria Carolina Blassioli; Laumann, Raul Alberto; Aquino, Michely Ferreira Santos; Paula, Débora Pires; Borges, Miguel

    2011-02-01

    We present a tritrophic analysis of the potential non-intended pleiotropic effects of cry1Ac gene derived from Bacillus thurigiensis (Bt) insertion in cotton (DeltaPine 404 Bt Bollgard® variety) on the emission of herbivore induced volatile compounds and on the attraction of the egg parasitoid Trichogramma pretisoum (Hymenoptera: Trichogrammatidae). Both the herbivore damaged Bt variety and its non-Bt isoline (DeltaPine DP4049 variety) produced volatiles in higher quantity when compared to undamaged plants and significantly attracted the egg parasitoids (T. pretiosum) when compared to undamaged plants. However, Trichogramma pretiosum did not differentiate between the transgenic and nontransgenic varieties, suggesting that the ratios between the compounds released by herbivory damaged -Bt cotton and herbivory damaged-non Bt cotton did not change significantly. Finally, no detrimental effect of the Bt genetic engineering was detected related to the volatile compounds released by Bollgard cotton on the behavior of the natural enemy studied. PMID:20521103

  17. Insecticide Treated and Untreated Bt and Conventional cottons Under High Insect Pressure in Large Field Cages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As a component of studies to compare performance of commercial Bt and non-Bt (conventional) cottons under different insect management systems, seven cotton varieties were exposed to extreme densities of bollworm (Helicoverpa zea Boddie) and tobacco budworm (Heliothis virescens F.) in large (1/8 acre...

  18. Aphid Honeydew Quality as a Food Source for Parasitoids Is Maintained in Bt Cotton

    PubMed Central

    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. PMID:25226521

  19. DNA screening reveals pink bollworm resistance to Bt cotton remains rare after a decade of exposure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transgenic crops producing toxins from the bacterium Bacillus thuringiensis (Bt) kill insect pests and can reduce reliance on insecticide sprays. Although Bt cotton and Bt corn covered 25 million ha worldwide in 2005, their success could be cut short by evolution of pest resistance. Monitoring the e...

  20. FROM Qutn TO Bt COTTON: DEVELOPMENT, ADOPTION AND PROSPECTS. A REVIEW.

    PubMed

    Maik, W; Abid, M A; Cheema, H M N; Khan, A A; Iqbal, M Z; Qayyum, A; Hanif, M; Bibi, N; Yuan, S N; Yasmeen, A; Mahmood, A; Ashraf, J

    2015-01-01

    Cotton has unique history of domestication, diversification, and utilization. Globally it is an important cash crop that provides raw material for textile industry. The story of cotton started from human civilization and the climax arrived with the efforts of developing transgenic cotton for various traits. Though conventional breeding brought steady improvement in developing resistance against biotic stresses but recent success story of gene transferfrom Bacillus thuringiensis into cotton showed game changing effects on cotton cultivation. Amongst various families of insecticidal proteins Bt Cry-toxins received more attention because of specificity against receptors on the cell membranes of insect midgut epithelial cells. Rapid Bt cotton adoption by farmers due to its economic and environmental benefits has changed the landscape of cotton cultivation in many countries. But the variable expression of Bt transgene in the newly developed Bt cotton genotypes in tropical environment is questionable. Variability of toxin level in different plant parts at various life stage of plant is an outcome of genotypic interaction with environmental factors. Temporal gene expression of Cry1Ac is also blamed for the epigenetic background in which transgene has been inserted. The presence of genotypes with sub-lethal level of Bt toxin might create resistance in Lepidopteron insects, limiting the use of Bt cotton in future, with the opportunityfor other resistance development strategies to get more attention like gene stacking. Until the farmers get access to more recent technology, best option is to delay the development of resistance by applying Insect Resistance Management (IRM) strategies. PMID:26841496

  1. Pest trade-offs in technology: reduced damage by caterpillars in Bt cotton benefits aphids

    PubMed Central

    Hagenbucher, Steffen; Wäckers, Felix L.; Wettstein, Felix E.; Olson, Dawn M.; Ruberson, John R.; Romeis, Jörg

    2013-01-01

    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. PMID:23486438

  2. A seed mixture increases dominance of resistance to Bt cotton in Helicoverpa zea.

    PubMed

    Brévault, Thierry; Tabashnik, Bruce E; Carrière, Yves

    2015-01-01

    Widely grown transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt) can benefit agriculture, but adaptation by pests threatens their continued success. Refuges of host plants that do not make Bt toxins can promote survival of susceptible insects and delay evolution of resistance, particularly if resistance is inherited as a recessive trait. However, data have been lacking to compare the dominance of resistance when Bt and non-Bt seeds are planted in random mixtures versus separate blocks. Here we report results from greenhouse experiments with transgenic cotton producing Bt toxin Cry1Ac and the bollworm, Helicoverpa zea, showing that the dominance of resistance was significantly higher in a seed mixture relative to a block of Bt cotton. The proportion of larvae on non-Bt cotton plants in the seed mixture was also significantly higher than expected under the null hypothesis of random distribution. In simulations based on observed survival, resistance evolved 2- to 4.5-fold faster in the seed mixture relative to separate blocks of Bt and non-Bt cotton. These findings support previous modelling results indicating that block refuges may be more effective than seed mixtures for delaying resistance in pests with mobile larvae and inherently low susceptibility to the toxins in Bt crops. PMID:25950459

  3. A seed mixture increases dominance of resistance to Bt cotton in Helicoverpa zea

    PubMed Central

    Brévault, Thierry; Tabashnik, Bruce E.; Carrière, Yves

    2015-01-01

    Widely grown transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt) can benefit agriculture, but adaptation by pests threatens their continued success. Refuges of host plants that do not make Bt toxins can promote survival of susceptible insects and delay evolution of resistance, particularly if resistance is inherited as a recessive trait. However, data have been lacking to compare the dominance of resistance when Bt and non-Bt seeds are planted in random mixtures versus separate blocks. Here we report results from greenhouse experiments with transgenic cotton producing Bt toxin Cry1Ac and the bollworm, Helicoverpa zea, showing that the dominance of resistance was significantly higher in a seed mixture relative to a block of Bt cotton. The proportion of larvae on non-Bt cotton plants in the seed mixture was also significantly higher than expected under the null hypothesis of random distribution. In simulations based on observed survival, resistance evolved 2- to 4.5-fold faster in the seed mixture relative to separate blocks of Bt and non-Bt cotton. These findings support previous modelling results indicating that block refuges may be more effective than seed mixtures for delaying resistance in pests with mobile larvae and inherently low susceptibility to the toxins in Bt crops. PMID:25950459

  4. Fate of Southern Green Stink Bug Egg Masses in Bt-Cotton, Round-up Ready Cotton, Soybeans and Peanuts.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is a need to characterize the mechanisms underlying population dynamics of stink bugs relative to major crops in the southeastern US. To this end, we investigated Southern green stink bug egg mortality by placing sentinel egg masses in plots of soybean, Bt-cotton, Round up Ready (RR) cotton a...

  5. Fate of southern green stink-bug eggs in Bt-cotton, Round-up ready cotton, soybeans and peanuts.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is a need to determine the life history of stink bugs relative to major crops in the area. To this end, we investigated Southern green stink bug egg mortality by placing sentinel egg masses in plots of soybean, Bt-cotton, Round up Ready (RR) cotton and peanut plants in the Southeast. Egg mass...

  6. Assessing beet armyworm damage on Bt and non-Bt cottons by visual observations and remote sensing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We evaluated damage, survival, and yield of beet armyworm, Spodoptera exigua (Hubner), populations on Bollgard II (ST 4357 BGII/RRF and AMX 1532RGII/RR), WideStrike™ (Phy 485 WRF), Bollgard® (DPL 444 BRRR), and non-Bt cottons (AMX 262R, Phy 425 RF) in the Lower Rio Grande Valley (LRGV) of Texas. Ex...

  7. Dominant resistance to Bt cotton and minor cross-resistance to Bt toxin Cry2Ab in cotton bollworm from China

    PubMed Central

    Jin, Lin; Wei, Yiyun; Zhang, Lei; Yang, Yihua; Tabashnik, Bruce E; Wu, Yidong

    2013-01-01

    Evolution of resistance by insect pests threatens the long-term benefits of transgenic crops that produce insecticidal proteins from Bacillus thuringiensis (Bt). Previous work has detected increases in the frequency of resistance to Bt toxin Cry1Ac in populations of cotton bollworm, Helicoverpa armigera, from northern China where Bt cotton producing Cry1Ac has been grown extensively for more than a decade. Confirming that trend, we report evidence from 2011 showing that the percentage of individuals resistant to a diagnostic concentration of Cry1Ac was significantly higher in two populations from different provinces of northern China (1.4% and 2.3%) compared with previously tested susceptible field populations (0%). We isolated two resistant strains: one from each of the two field-selected populations. Relative to a susceptible strain, the two strains had 460- and 1200-fold resistance to Cry1Ac, respectively. Both strains had dominant resistance to a diagnostic concentration of Cry1Ac in diet and to Bt cotton leaves containing Cry1Ac. Both strains had low, but significant cross-resistance to Cry2Ab (4.2- and 5.9-fold), which is used widely as the second toxin in two-toxin Bt cotton. Compared with resistance in other strains of H. armigera, the resistance in the two strains characterized here may be especially difficult to suppress. PMID:24478804

  8. Assessment of biological and biochemical indicators in soil under transgenic Bt and non-Bt cotton crop in a sub-tropical environment.

    PubMed

    Sarkar, Binoy; Patra, Ashok K; Purakayastha, T J; Megharaj, Mallavarapu

    2009-09-01

    There is concern that transgenic Bt-crops carry genes that could have undesirable effects on natural and agro-ecosystem functions. We investigated the effect of Bt-cotton (expressing the Cry 1Ac protein) on several microbial and biochemical indicators in a sandy loam soil. Bt-cotton (MRC-6301Bt) and its non-transgenic near-isoline (MRC-6301) were grown in a net-house on a sandy clay loam soil. Soil and root samples were collected 60, 90, and 120 days after sowing. Soil from a control (no-crop) treatment was also included. Samples were analysed for microbial biomass C, N and P (MBC, MBN, MBP), total organic carbon (TOC), and several soil enzyme activities. The microbial quotient (MQ) was calculated as the ratio of MBC-to-TOC. The average of the three sampling events revealed a significant increase in MBC, MBN, MBP and MQ in the soil under Bt-cotton over the non-Bt isoline. The TOC was similar in Bt and non-Bt systems. Potential N mineralization, nitrification, nitrate reductase, and acid and alkaline phosphatase activities were all higher in the soil under Bt-cotton. Root dry weights were not different (P > 0.05), but root volume of Bt-cotton was higher on 90 and 120 days than that of non-Bt cotton. The time of sampling strongly affected the above parameters, with most being highest on 90 days after sowing. We concluded from the data that there were some positive or no negative effects of Bt-cotton on the studied indicators, and therefore cultivation of Bt-cotton appears to be no risk to soil ecosystem functions. PMID:18720017

  9. Soil microflora and enzyme activities in rhizosphere of Transgenic Bt cotton hybrid under different intercropping systems and plant protection schedules

    NASA Astrophysics Data System (ADS)

    Biradar, D. P.; Alagawadi, A. R.; Basavanneppa, M. A.; Udikeri, S. S.

    2012-04-01

    Field experiments were conducted over three rainy seasons of 2005-06 to 2007-08 on a Vertisol at Dharwad, Karnataka, India to study the effect of intercropping and plant protection schedules on productivity, soil microflora and enzyme activities in the rhizosphere of transgenic Bt cotton hybrid. The experiment consisted of four intercropping systems namely, Bt cotton + okra, Bt cotton + chilli, Bt cotton + onion + chilli and Bt cotton + redgram with four plant protection schedules (zero protection, protection for Bt cotton, protection for intercrop and protection for both crops). Observations on microbial populations and enzyme activities were recorded at 45, 90, 135 and 185 (at harvest) days after sowing (DAS). Averaged over years, Bt cotton + okra intercropping had significantly higher total productivity than Bt cotton + chilli and Bt cotton + redgram intercropping system and was similar to Bt cotton + chilli + onion intercropping system. With respect to plant protection schedules for bollworms, protection for both cotton and intercrops recorded significantly higher yield than the rest of the treatments. Population of total bacteria, fungi, actinomycetes, P-solubilizers, free-living N2 fixers as well as urease, phosphatase and dehydrogenase enzyme activities increased up to 135 days of crop growth followed by a decline. Among the intercropping systems, Bt cotton + chilli recorded significantly higher population of microorganisms and enzyme activities than other cropping systems. While Bt cotton with okra as intercrop recorded the least population of total bacteria and free-living N2 fixers as well as urease activity. Intercropping with redgram resulted in the least population of actinomycetes, fungi and P-solubilizers, whereas Bt cotton with chilli and onion recorded least activities of dehydrogenase and phosphatase. Among the plant protection schedules, zero protection recorded maximum population of microorganisms and enzyme activities. This was followed by the

  10. [Effects of high temperature on Bt protein content and nitrogen metabolic physiology in boll wall of Bt cotton].

    PubMed

    Wang, Jun; Abidallah, Eltayib H M A; Hua, Ming-ming; Heng, Li; Lyu, Chun-hua; Chen, De-hua

    2015-10-01

    Bt cotton cultivar Sikang 1 (a conventional cultivar) and Sikang 3 (a hybrid cultivar) from China, and 99B (a conventional cultivar) and Daiza 1 (a hybrid cultivar) from USA were selected as experimental materials, the ball wall Bt protein content and nitrogen metabolic physiology were investigated under different high temperature levels at peak boll stage. The results showed that the Bt protein content of boll wall decreased with the increasing temperature. Compared with the control (32 °C, the boll wall Bt protein content decreased significantly when the temperature was above 38 °C for the conventional cultivars and above 40 °C for the hybrid cultivars. The Bt protein contents of cultivar Sikang 1 and 99B decreased by 53.0% and 69.5% respectively with the temperature at 38 °C, and that of cultivar Sikang 3 and Daiza 1 decreased by 64.8% and 54.1% respectively with the temperature at 40 °C. Greater reductions in the boll wall soluble protein contents and GPT activities, larger increments for the boll wall free amino acid contents and proteinsase activities were also observed when the boll wall Bt protein content was significantly reduced. Therefore, high temperature resulted in the reduction of Bt protein synthesis and increase of the insecticidal protein degradation in the boll wall significantly, which caused the reductions in boll wall Bt protein content and insect resistance. PMID:26995932

  11. Pink Bollworm Resistance to Bt Cotton: Still Rare After All These Years.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transgenic crops producing Bacillus thuringiensis (Bt) toxins reduce reliance on insecticides, but evolution of resistance by pests could cut short their usefulness. Pink bollworm is a major pest that has experienced intense selection for resistance to Bt cotton in Arizona since 1997. Unexpectedly...

  12. Sustained susceptibility of Pink Bollworm to Bt cotton in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Evolution of resistance by pests can reduce the benefits of transgenic crops that produce toxins from Bacillus thuringiensis (Bt) for insect control. One of the world's most important cotton pests, pink bollworm (Pectinophora gossypiella), has been targeted for control by transgenic cotton producin...

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

    PubMed Central

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

    2016-01-01

    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. PMID:27075171

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

    PubMed

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

    2016-01-01

    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. PMID:27075171

  15. Multi-Toxin Resistance Enables Pink Bollworm Survival on Pyramided Bt Cotton.

    PubMed

    Fabrick, Jeffrey A; Unnithan, Gopalan C; Yelich, Alex J; DeGain, Ben; Masson, Luke; Zhang, Jie; Carrière, Yves; Tabashnik, Bruce E

    2015-01-01

    Transgenic crops producing Bacillus thuringiensis (Bt) proteins kill key insect pests, providing economic and environmental benefits. However, the evolution of pest resistance threatens the continued success of such Bt crops. To delay or counter resistance, transgenic plant "pyramids" producing two or more Bt proteins that kill the same pest have been adopted extensively. Field populations of the pink bollworm (Pectinophora gossypiella) in the United States have remained susceptible to Bt toxins Cry1Ac and Cry2Ab, but field-evolved practical resistance to Bt cotton producing Cry1Ac has occurred widely in India. Here we used two rounds of laboratory selection to achieve 18,000- to 150,000-fold resistance to Cry2Ab in pink bollworm. Inheritance of resistance to Cry2Ab was recessive, autosomal, conferred primarily by one locus, and independent of Cry1Ac resistance. We created a strain with high resistance to both toxins by crossing the Cry2Ab-resistant strain with a Cry1Ac-resistant strain, followed by one selection with Cry2Ab. This multi-toxin resistant strain survived on field-collected Bt cotton bolls producing both toxins. The results here demonstrate the risk of evolution of resistance to pyramided Bt plants, particularly when toxins are deployed sequentially and refuges are scarce, as seen with Bt cotton and pink bollworm in India. PMID:26559899

  16. Suppressing Resistance to Bt Cotton with Sterile Insect Releases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transgenic plants producing insecticidal proteins from Bacillus thuringiensis (Bt) are grown widely to control pests, but evolution of insect resistance can reduce their efficacy. The predominant strategy for delaying insect resistance to Bt crops requires refuges of non-Bt host plants to provide s...

  17. Evolutionary ecology of insect adaptation to Bt crops

    PubMed Central

    Carrière, Yves; Crowder, David W; Tabashnik, Bruce E

    2010-01-01

    Transgenic crops producing Bacillus thuringiensis (Bt) toxins are used worldwide to control major pests of corn and cotton. Development of strategies to delay the evolution of pest resistance to Bt crops requires an understanding of factors affecting responses to natural selection, which include variation in survival on Bt crops, heritability of resistance, and fitness advantages associated with resistance mutations. The two main strategies adopted for delaying resistance are the refuge and pyramid strategies. Both can reduce heritability of resistance, but pyramids can also delay resistance by reducing genetic variation for resistance. Seasonal declines in the concentration of Bt toxins in transgenic cultivars, however, can increase the heritability of resistance. The fitness advantages associated with resistance mutations can be reduced by agronomic practices, including increasing refuge size, manipulating refuges to increase fitness costs, and manipulating Bt cultivars to reduce fitness of resistant individuals. Manipulating costs and fitness of resistant individuals on transgenic insecticidal crops may be especially important for thwarting evolution of resistance in haplodiploid and parthenogenetic pests. Field-evolved resistance to Bt crops in only five pests during the last 14 years suggests that the refuge strategy has successfully delayed resistance, but the accumulation of resistant pests could accelerate. PMID:25567947

  18. Determining the major Bt refuge crops for cotton bollworm in North China.

    PubMed

    Ye, Le-Fu; Fu, Xue; Ouyang, Fang; Xie, Bao-Yu; Ge, Feng

    2015-12-01

    Evaluation of the effectiveness of refuge strategies involved in cotton bollworm Bt resistance management would be aided by technologies that allow monitoring and quantification of key factors that affect the process under field conditions. We hypothesized that characterization of stable carbon and nitrogen isotopes in adult bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) moths may aid in determining the larval host that they developed upon. We found moths reared from larvae fed on peanut, soybean or cotton, respectively, could be differentiated using isotopic analyses that also corresponded to their respective larval host origins. These techniques were then used to classify feral second-generation bollworm moths caught in Bt cotton (Gossypium hirsutum) fields into different populations based on their isotopic signatures. In 2006-2007 feral moths captured in Bt cotton fields predominantly correlated with the peanut (Arachis hypogea) having served as their larval host, indicating this is the most important refuge crop for Bt-susceptible bollworm individuals (providing 58%-64% individuals) during independent moth peaks for the second generation in North China. The remaining feral moths correlated with soybean (Glycine max) (0-10%); other C3 plant (20%-22%) and non-C3 plant (12%-14%) host types also provided some Bt-sensitive moths. Field observations showed that peanut constitutes the primary refuge crop contributing to sustaining Bt-susceptible moths dispersing into cotton in North China. These results suggest that peanut may be a more effective refuge to sustain Bt-susceptible bollworm individuals and reduce the risk of development of a Bt-resistant biotype. PMID:25196072

  19. Comparative benefit of Bt and Non-Bt cotton under different insect management strategies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transgenic cotton varieties expressing insecticidal proteins from the soil bacterium, Bacillus thuringiensis, have revolutionized caterpillar control, particularly for tobacco budworm. However, these transgenic cottons have never produced a high dose of toxin for control of bollworm. Even second g...

  20. Target and nontarget effects of novel "triple-stacked" Bt-transgenic cotton 1: canopy arthropod communities.

    PubMed

    Whitehouse, M E A; Wilson, L J; Davies, A P; Cross, D; Goldsmith, P; Thompson, A; Harden, S; Baker, G

    2014-02-01

    Transgenic cotton varieties (Bollgard II) expressing two proteins (Cry1Ac and Cry2Ab) from Bacillus thuringiensis (Bt) have been widely adopted in Australia to control larvae of Helicoverpa. A triple-stacked Bt-transgenic cotton producing Cry1Ac, Cry2Ab, and Vip3A proteins (Genuity Bollgard III) is being developed to reduce the chance that Helicoverpa will develop resistance to the Bt proteins. Before its introduction, nontarget effects on the agro-ecosystem need to be evaluated under field conditions. By using beatsheet and suction sampling methods, we compared the invertebrate communities of unsprayed non-Bt-cotton, Bollgard II, and Bollgard III in five experiments across three sites in Australia. We found significant differences between invertebrate communities of non-Bt and Bt (Bollgard II and Bollgard III) cotton only in experiments where lepidopteran larval abundance was high. In beatsheet samples where lepidopterans were absent (Bt crops), organisms associated with flowers and bolls in Bt-cotton were more abundant. In suction samples, where Lepidoptera were present (i.e., in non-Bt-cotton), organisms associated with damaged plant tissue and frass were more common. Hence in our study, Bt- and non-Bt-cotton communities only differed when sufficient lepidopteran larvae were present to exert both direct and indirect effects on species assemblages. There was no overall significant difference between Bollgard II and III communities, despite the addition of the Vip gene in Bollgard III. Consequently, the use of Bollgard III in Australian cotton provides additional protection against the development of resistance by Helicoverpa to Bt toxins, while having no additional effect on cotton invertebrate communities. PMID:24472211

  1. Economic impacts and impact dynamics of Bt (Bacillus thuringiensis) cotton in India

    PubMed Central

    Kathage, Jonas; Qaim, Matin

    2012-01-01

    Despite widespread adoption of genetically modified crops in many countries, heated controversies about their advantages and disadvantages continue. Especially for developing countries, there are concerns that genetically modified crops fail to benefit smallholder farmers and contribute to social and economic hardship. Many economic studies contradict this view, but most of them look at short-term impacts only, so that uncertainty about longer-term effects prevails. We address this shortcoming by analyzing economic impacts and impact dynamics of Bt cotton in India. Building on unique panel data collected between 2002 and 2008, and controlling for nonrandom selection bias in technology adoption, we show that Bt has caused a 24% increase in cotton yield per acre through reduced pest damage and a 50% gain in cotton profit among smallholders. These benefits are stable; there are even indications that they have increased over time. We further show that Bt cotton adoption has raised consumption expenditures, a common measure of household living standard, by 18% during the 2006–2008 period. We conclude that Bt cotton has created large and sustainable benefits, which contribute to positive economic and social development in India. PMID:22753493

  2. Economic impacts and impact dynamics of Bt (Bacillus thuringiensis) cotton in India.

    PubMed

    Kathage, Jonas; Qaim, Matin

    2012-07-17

    Despite widespread adoption of genetically modified crops in many countries, heated controversies about their advantages and disadvantages continue. Especially for developing countries, there are concerns that genetically modified crops fail to benefit smallholder farmers and contribute to social and economic hardship. Many economic studies contradict this view, but most of them look at short-term impacts only, so that uncertainty about longer-term effects prevails. We address this shortcoming by analyzing economic impacts and impact dynamics of Bt cotton in India. Building on unique panel data collected between 2002 and 2008, and controlling for nonrandom selection bias in technology adoption, we show that Bt has caused a 24% increase in cotton yield per acre through reduced pest damage and a 50% gain in cotton profit among smallholders. These benefits are stable; there are even indications that they have increased over time. We further show that Bt cotton adoption has raised consumption expenditures, a common measure of household living standard, by 18% during the 2006-2008 period. We conclude that Bt cotton has created large and sustainable benefits, which contribute to positive economic and social development in India. PMID:22753493

  3. Effects of Bt cotton on Thrips tabaci (Thysanoptera: Thripidae) and its predator, Orius insidiosus (Hemiptera: Anthocoridae).

    PubMed

    Kumar, Rishi; Tian, Jun-Ce; Naranjo, Steven E; Shelton, Anthony M

    2014-06-01

    Laboratory studies were conducted to investigate tritrophic transfer of insecticidal Cry proteins from transgenic cotton to an herbivore and its predator, and to examine effects of these proteins on the predator's development, survival, and reproduction. Cry1Ac and Cry2Ab proteins from the bacterium Bacillus thuringiensis (Bt) produced in Bollgard-II (BG-II, Event 15985) cotton plants were acquired by Thrips tabaci Lindeman (Thysanoptera: Thripidae), an important sucking pest of cotton, and its generalist predator, Orius insidiosus (Say) (Hemiptera: Anthocoridae). The average protein titers in BG-II cotton leaves were 1,256 and 43,637 ng Cry1Ac and Cry2Ab per gram fresh leaf tissue, respectively. At the second trophic level, larvae of T. tabaci reared on BG-II cotton for 48-96 h had 22.1 and 2.1% of the Cry1Ac and Cry2Ab levels expressed in leaves, respectively. At the third trophic level, O. insidiosus that fed on T. tabaci larvae had 4.4 and 0.3% of the Cry1Ac and Cry2Ab protein levels, respectively, expressed in BG-II plants. O. insidiosus survivorship, time of nymphal development, adult weight, preoviposition and postoviposition periods, fecundity, and adult longevity were not adversely affected owing to consumption of T. tabaci larvae that had fed on BG-II cotton compared with non-Bt cotton. Our results indicate that O. insidiosus, a common predator of T. tabaci, is not harmed by BG-II cotton when exposed to Bt proteins through its prey. Thus, O. insidiosus can continue to provide important biological control services in the cotton ecosystem when BG-II cotton is used to control primary lepidopteran pests. PMID:25026649

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

    PubMed

    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. PMID:25170907

  5. Identification of Top-Down Forces Regulating Cotton Aphid Population Growth in Transgenic Bt Cotton in Central China

    PubMed Central

    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. PMID:25170907

  6. Mortality of bollworm and tobacco budworm larvae exposed to microbial and chemical insecticides in treated Bt and non-Bt cotton assays

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Laboratory colonies of bollworm (Helicoverpa zea Boddie) and tobacco budworm (Heliothis virescens F.) were exposed to microbial and chemical insecticides on non-Bt (DP1441) and Bt (DP1321) cotton leaves in spray-table and field-plot experiments. The microbial insecticides included commercial formula...

  7. Monitoring and adaptive resistance management in Australia for Bt-cotton: current status and future challenges.

    PubMed

    Downes, Sharon; Mahon, Rod; Olsen, Karen

    2007-07-01

    In the mid-1990 s the Australian Cotton industry adopted an insect-resistant variety of cotton (Ingard) which expresses the Bt toxin Cry1Ac that is specific to a group of insects including the target Helicoverpa armigera. A conservative resistance management plan (RMP), that restricted the area planted to Ingard, was implemented to preserve the efficacy of Cry1Ac until two-gene transgenic cotton was available. In 2004/05 Bollgard II replaced Ingard as the transgenic cotton available in Australia. It improves on Ingard by incorporating an additional insecticidal protein (Cry2Ab). If an appropriate refuge is grown, there is no restriction on the area planted to Bollgard II. In 2004/05 and 2005/06 the Bollgard II acreage represented approximately 80 of the total area planted to cotton in Australia. The sensitivity of field-collected populations of H. armigera to Bt products was assayed before and subsequent to the widespread deployment of Ingard cotton. In 2002 screens against Cry2Ab were developed in preparation for replacement of Ingard with Bollgard II. There have been no reported field failures of Bollgard II due to resistance. However, while alleles that confer resistance to H. armigera in the field are rare for Cry1Ac, they are surprisingly common for Cry2Ab. We present an overview of the current approach adopted in Australia to monitor and adaptively manage resistance to Bt-cotton in field populations of H. armigera and discuss the implications of our findings to date. We also highlight future challenges for resistance management in Australia, many of which extend to other Bt-crop and pest systems. PMID:17470372

  8. Reduced foliage herbivory in Bt cotton benefits phloem-feeding insects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetically modified cotton plants that express Lepidoptera-active Cry toxins from Bacillus thuringiensis (Bt) are grown on 15 millions hectares worldwide. Numerous studies have established that these plants pose a negligible risk to non-target arthropods due to the narrow spectrum of activity of th...

  9. Effectiveness of transgenic Bt cottons against noctuids in the Lower Rio Grande Valley of Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Evaluations of the comparative efficacy of Bacillus thuringiensis Bollgard, Bollgard II and non-Bt traits expressing cottons for control of the noctuid complex composed of bollworms, Helicoverpa zea (Boddie), fall armyworms, Spodoptera frugiperda (J.E. Smith), beet armyworms, Spodoptera exigua (Hübn...

  10. Reduced foliage herbivory in Bt cotton benefits phloem-feeding insects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetically engineered cotton plants that express Lepidoptera-active Cry toxins from Bacillus thuringiensis (Bt) are grown on 15 millions hectares worldwide. Numerous studies have established that these plants pose a negligible risk to non-target arthropods due to the narrow spectrum of activity of ...

  11. Release of the first BT Acala cotton cultivar, Acala 1517-99W

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Acala 1517-99W (Widestrike) is a trademark of Dow AgroSciences LLC for its proprietary Bt cotton trait expressing Cry1F and Cry1Ac insecticidal proteins from Bacillus thuringiensis. This Widestrike trait is intended to offer season long protection against a broad spectrum of insect pests including b...

  12. Fitness Cost of Resistance to Bt Cotton Linked with Increased Gossypol Content in Pink Bollworm Larvae

    PubMed Central

    Williams, Jennifer L.; Ellers-Kirk, Christa; Orth, Robert G.; Gassmann, Aaron J.; Head, Graham; Tabashnik, Bruce E.; Carrière, Yves

    2011-01-01

    Fitness costs of resistance to Bacillus thuringiensis (Bt) crops occur in the absence of Bt toxins, when individuals with resistance alleles are less fit than individuals without resistance alleles. As costs of Bt resistance are common, refuges of non-Bt host plants can delay resistance not only by providing susceptible individuals to mate with resistant individuals, but also by selecting against resistance. Because costs typically vary across host plants, refuges with host plants that magnify costs or make them less recessive could enhance resistance management. Limited understanding of the physiological mechanisms causing fitness costs, however, hampers attempts to increase costs. In several major cotton pests including pink bollworm (Pectinophora gossypiella), resistance to Cry1Ac cotton is associated with mutations altering cadherin proteins that bind this toxin in susceptible larvae. Here we report that the concentration of gossypol, a cotton defensive chemical, was higher in pink bollworm larvae with cadherin resistance alleles than in larvae lacking such alleles. Adding gossypol to the larval diet decreased larval weight and survival, and increased the fitness cost affecting larval growth, but not survival. Across cadherin genotypes, the cost affecting larval growth increased as the gossypol concentration of larvae increased. These results suggest that increased accumulation of plant defensive chemicals may contribute to fitness costs associated with resistance to Bt toxins. PMID:21738799

  13. Efficacy of various Bt Cotton against the Black Cutworm.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Laboratory bioassays, field cages, and large experimental plots were utilized to determine the relative efficacy of Bollgard®, Bollgard II®, and WideStrike™ against the black cutworm. In most studies, WideStrike™ caused the highest mortality to all instars examined compared to non-Bt, Bollgard®, or...

  14. Fourteen Years of Bt Cotton Advances IPM in Arizona

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The pink bollworm, Pectinophora gossypiella (Saunders) first invaded Arizona in 1926 and has been a key pest of cotton since the early 1960’s. A broad range of tactics have been developed to manage this pest including a variety of cultural methods, mating disruption via pheromones, sterile insect re...

  15. Comparative studies on the effects of Bt-transgenic and nontransgenic cotton on arthropod diversity, seedcotton yield and bollworms control.

    PubMed

    Dhillon, M K; Sharma, H C

    2013-01-01

    The effectiveness of commercial Bt-cotton in pest management, influence on arthropod diversity, natural enemies, and toxin flow in the insect fauna under field conditions were studied keeping in view the need to assess bioefficacy and biosafety of Bt-transgenic cotton. There were no significant differences in oviposition by Helicoverpa armigera on Bt-transgenic and non-transgenic cottons (9.2 versus 9.6 eggs plants(-100)), while the numbers of H. armigera larvae were significantly more on non-transgenic than on Bt-transgenic (10.4 versus 4.0 larvae plants(-100)) cotton. The Bt-cotton had significantly more number of mature opened bolls (9.6 versus 4.4 bolls plant(-1)), lower bollworm damage (12.8 versus 40.2% bolls damaged), and higher seedcotton yield (667.7 versus 231.7 kg ha 1). Population of cotton leafhopper, Amrasca biguttula biguttula was lower (582.2 versus 732.2 leafhoppers plants(-100)), while that of whitefly, Bemisia tabaci was higher on Bt-transgenic (65.2 versus 45.6 whiteflies plants(-100)) than on non-transgenic cotton. There was no significant influence of Bt-transgenic cotton on abundance of natural enemies of crop pests - chrysopids (9.6 versus 8.4 chrysopids plants(-100), ladybird beetles (16.0 versus 10.8 ladybirds plants(-100)), and spiders (128.4 versus 142.8 spiders plants(-100)). There were no significant differences in H. ormigera egg (19.8 versus 20.9%), larval (7.4 versus 9.6%), and larval-pupal (1.3 versus 2.9%) parasitism on Bt-transgenic and non-transgenic cottons in the farmer's fields. The parasitism in larvae of H. armigera was far lower than that of the eggs, which might be because of early mortality of H. armigera prior to parasitoid development in the host larvae. Although, Cry1Ac Bt toxin was detected in Cheilomenes sexmoculatus, chrysopids, A. bigutulla bigutulla, Thrips taboci, Myllocerus sp., Oxycarenus laetus, Dysdercus koenigii, spiders, bugs, and grasshoppers, no significant differences were observed in their abundance on

  16. Impact of Single and Stacked Insect-Resistant Bt-Cotton on the Honey Bee and Silkworm

    PubMed Central

    Niu, Lin; Ma, Yan; Mannakkara, Amani; Zhao, Yao; Ma, Weihua; Lei, Chaoliang; Chen, Lizhen

    2013-01-01

    Transgenic insect-resistant cotton (Bt cotton) has been extensively planted in China, but its effects on non-targeted insect species such as the economically important honey bee (Apis mellifera) and silkworm (Bombyx mori) currently are unknown. In this study, pollen from two Bt cotton cultivars, one expressing Cry1Ac/EPSPS and the other expressing Cry1Ac/Cry2Ab, were used to evaluate the effects of Bt cotton on adult honey bees and silkworm larvae. Laboratory feeding studies showed no adverse effects on the survival, cumulative consumption, and total hemocyte count (THC) of A. mellifera fed with Bt pollen for 7 days. No effects on the survival or development of B. mori larvae were observed either. A marginally significant difference between Cry1Ac/Cry2Ab cotton and the conventional cotton on the THC of the 3rd day of 5th B. mori instar larvae was observed only at the two highest pollen densities (approximately 900 and 8000 grains/cm2), which are much higher than the pollen deposition that occurs under normal field conditions. The results of this study show that pollen of the tested Bt cotton varieties carried no lethal or sublethal risk for A. mellifera, and the risk for B. mori was negligible. PMID:24039838

  17. Impact of Water Content and Temperature on the Degradation of Cry1Ac Protein in Leaves and Buds of Bt Cotton in the Soil

    PubMed Central

    Zhang, Mei-jun; Feng, Mei-chen; Xiao, Lu-jie; Song, Xiao-yan; Yang, Wu-de; Ding, Guang-wei

    2015-01-01

    Determining the influence of soil environmental factors on degradation of Cry1Ac protein from Bt cotton residues is vital for assessing the ecological risks of this commercialized transgenic crop. In this study, the degradation of Cry1Ac protein in leaves and in buds of Bt cotton in soil was evaluated under different soil water content and temperature settings in the laboratory. An exponential model and a shift-log model were used to fit the degradation dynamics of Cry1Ac protein and estimate the DT50 and DT90 values. The results showed that Cry1Ac protein in the leaves and buds underwent rapid degradation in the early stage (before day 48), followed by a slow decline in the later stage under different soil water content and temperature. Cry1Ac protein degraded the most rapidly in the early stage at 35°C with 70% soil water holding capacity. The DT50 values were 12.29 d and 10.17 d and the DT90 values were 41.06 d and 33.96 d in the leaves and buds, respectively. Our findings indicated that the soil temperature was a major factor influencing the degradation of Cry1Ac protein from Bt cotton residues. Additionally, the relative higher temperature (25°C and 35°C) was found to be more conducive to degradation of Cry1Ac protein in the soil and the greater water content (100%WHC) retarded the process. These findings suggested that under appropriate soil temperature and water content, Cry1Ac protein from Bt cotton residues will not persist and accumulate in soil. PMID:25559638

  18. Incipient Resistance of Helicoverpa punctigera to the Cry2Ab Bt Toxin in Bollgard II® Cotton

    PubMed Central

    Downes, Sharon; Parker, Tracey; Mahon, Rod

    2010-01-01

    Combinations of dissimilar insecticidal proteins (“pyramids”) within transgenic plants are predicted to delay the evolution of pest resistance for significantly longer than crops expressing a single transgene. Field-evolved resistance to Bacillus thuringiensis (Bt) transgenic crops has been reported for first generation, single-toxin varieties and the Cry1 class of proteins. Our five year data set shows a significant exponential increase in the frequency of alleles conferring Cry2Ab resistance in Australian field populations of Helicoverpa punctigera since the adoption of a second generation, two-toxin Bt cotton expressing this insecticidal protein. Furthermore, the frequency of cry2Ab resistance alleles in populations from cropping areas is 8-fold higher than that found for populations from non-cropping regions. This report of field evolved resistance to a protein in a dual-toxin Bt-crop has precisely fulfilled the intended function of monitoring for resistance; namely, to provide an early warning of increases in frequencies that may lead to potential failures of the transgenic technology. Furthermore, it demonstrates that pyramids are not ‘bullet proof’ and that rapid evolution to Bt toxins in the Cry2 class is possible. PMID:20830203

  19. Incipient resistance of Helicoverpa punctigera to the Cry2Ab Bt toxin in Bollgard II cotton.

    PubMed

    Downes, Sharon; Parker, Tracey; Mahon, Rod

    2010-01-01

    Combinations of dissimilar insecticidal proteins ("pyramids") within transgenic plants are predicted to delay the evolution of pest resistance for significantly longer than crops expressing a single transgene. Field-evolved resistance to Bacillus thuringiensis (Bt) transgenic crops has been reported for first generation, single-toxin varieties and the Cry1 class of proteins. Our five year data set shows a significant exponential increase in the frequency of alleles conferring Cry2Ab resistance in Australian field populations of Helicoverpa punctigera since the adoption of a second generation, two-toxin Bt cotton expressing this insecticidal protein. Furthermore, the frequency of cry2Ab resistance alleles in populations from cropping areas is 8-fold higher than that found for populations from non-cropping regions. This report of field evolved resistance to a protein in a dual-toxin Bt-crop has precisely fulfilled the intended function of monitoring for resistance; namely, to provide an early warning of increases in frequencies that may lead to potential failures of the transgenic technology. Furthermore, it demonstrates that pyramids are not 'bullet proof' and that rapid evolution to Bt toxins in the Cry2 class is possible. PMID:20830203

  20. Cross-resistance and interactions between Bt toxins Cry1Ac and Cry2Ab against the cotton bollworm

    PubMed Central

    Wei, Jizhen; Guo, Yuyuan; Liang, Gemei; Wu, Kongming; Zhang, Jie; Tabashnik, Bruce E.; Li, Xianchun

    2015-01-01

    To delay evolution of pest resistance to transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt), the "pyramid" strategy uses plants that produce two or more toxins that kill the same pest. We conducted laboratory diet experiments with the cotton bollworm, Helicoverpa armigera, to evaluate cross-resistance and interactions between two toxins in pyramided Bt cotton (Cry1Ac and Cry2Ab). Selection with Cry1Ac for 125 generations produced 1000-fold resistance to Cry1Ac and 6.8-fold cross-resistance to Cry2Ab. Selection with Cry2Ab for 29 generations caused 5.6-fold resistance to Cry2Ab and 61-fold cross-resistance to Cry1Ac. Without exposure to Bt toxins, resistance to both toxins decreased. For each of the four resistant strains examined, 67 to 100% of the combinations of Cry1Ac and Cry2Ab tested yielded higher than expected mortality, reflecting synergism between these two toxins. Results showing minor cross-resistance to Cry2Ab caused by selection with Cry1Ac and synergism between these two toxins against resistant insects suggest that plants producing both toxins could prolong the efficacy of Bt cotton against this pest in China. Including toxins against which no cross-resistance occurs and integrating Bt cotton with other control tactics could also increase the sustainability of management strategies. PMID:25586723

  1. Spatial Distribution of Eggs of Alabama argillacea Hübner and Heliothis virescens Fabricius (Lepidoptera: Noctuidae) on Bt and non-Bt Cotton.

    PubMed

    Rodrigues, Tatiana R; Fernandes, Marcos G; Degrande, Paulo E; Mota, Thiago A

    2015-01-01

    Among the options to control Alabama argillacea (Hübner, 1818) and Heliothis virescens (Fabricius, 1781) on cotton, insecticide spraying and biological control have been extensively used. The GM'Bt' cotton has been introduced as an extremely viable alternative, but it is yet not known how transgenic plants affect populations of organisms that are interrelated in an agroecosystem. For this reason, it is important to know how the spatial arrangement of pests and beneficial insect are affected, which may call for changes in the methods used for sampling these species. This study was conducted with the goal to investigate the pattern of spatial distribution of eggs of A. argillacea and H. virescens in DeltaOpal™ (non-Bt) and DP90B™ Bt cotton cultivars. Data were collected during the agricultural year 2006/2007 in two areas of 5,000 m2, located in in the district of Nova América, Caarapó municipality. In each sampling area, comprising 100 plots of 50 m2, 15 evaluations were performed on two plants per plot. The sampling consisted in counting the eggs. The aggregation index (variance/mean ratio, Morisita index and exponent k of the negative binomial distribution) and chi-square fit of the observed and expected values to the theoretical frequency distribution (Poisson, Binomial and Negative Binomial Positive), showed that in both cultivars, the eggs of these species are distributed according to the aggregate distribution model, fitting the pattern of negative binomial distribution. PMID:26628025

  2. [Advances in effects of insecticidal crystal proteins released from transgenic Bt crops on soil ecology].

    PubMed

    Zhou, Xue-Yong; Liu, Ning; Zhao, Man; Li, He; Zhou, Lang; Tang, Zong-Wen; Cao, Fei; Li, Wei

    2011-05-01

    With the large scale cultivation of transgenic crops expressing Bacillus thuringiensis (Bt) insecticidal crystal proteins in the world, the problem of environmental safety caused by these Bt crops has received extensive attention. These insecticidal crystal proteins can be released into the soil continuously in the growing period of Bt plants. If their accumulation of the insecticidal crystal proteins exceeds consumption by insect larvae and degradation by the environmental factors, these insecticidal crystal proteins could constitute a hazard to non-target insects and soil microbiota. There are three main ways to release insecticidal crystal proteins into soil for Bt plants: root exudates, pollen falling, and crop reside returning. The Bt insecticidal crystal proteins released into soil can be adsorbed rapidly by active soil particles and the absorption equilibrium attained within 1-3 h. The adsorption protects Bt insecticidal crystal proteins against soil microbial degradation or enzyme degradation, which leads to remarkable prolong of the persistence of insecticidal activity. The change of soil microorganism species is an important index for evaluating the effect of Bt plants on soil ecology. The research showed that these insecticidal crystal proteins released by the Bt plant root exudates or Bt organism had no toxicity to the soil earthworms, nematodes, protozoa, bacteria and fungi; however, it could reduce the mycelium length of the arbuscular mycorrhizal fungi (AMF) and restrain AMF to form invasion unit. The influencing degree of Bt protein on soil enzyme activity varied with the releasing modes or growth period of Bt crops. Bt Cry1Ab protein can be taken up from soil by parts of following crops; however, different results were obtained with different commercial kits. To better understand the soil ecological evaluation about the insecticidal crystal proteins released from transgenic Bt crops, this review provides a comprehensive overview about the release

  3. Influence of Dual-Bt Protein Corn on Bollworm, Helicoverpa zea (Boddie), Survivorship on Bollgard II Cotton

    PubMed Central

    Gore, J.; Catchot, A.; Cook, D.; Musser, F.; Caprio, M.

    2016-01-01

    Similar Cry proteins are expressed in both Bt corn, Zea mays L., and cotton, Gossypium hirsutum (L.), commercial production systems. At least one generation of corn earworm, Helicoverpa zea (Boddie), completes development on field corn in the Mid-South before dispersing across the landscape into other crop hosts like cotton. A concern is that Bt corn hybrids may result in selection for H. zea populations with a higher probability of causing damage to Bt cotton. The objective of this study was to determine the susceptibility of H. zea offspring from moths that developed on non-Bt and VT Triple Pro (VT3 PRO) field corn to lyophilized Bollgard II cotton tissue expressing Cry1Ac and Cry2Ab. Offspring of individuals reared on VT3 PRO expressing Cry1A.105 and Cry2Ab had a significantly higher LC50 two out of the three years this study was conducted. Excess larvae were placed on artificial diet and allowed to pupate to determine if there were any inheritable fitness costs associated with parental development on VT3 PRO corn. Offspring resulting from males collected from VT3 PRO had significantly lower pupal weight and longer pupal duration compared with offspring of individuals collected from non-Bt corn. However, offspring from females collected from VT3 PRO were not different from non-Bt offspring. Paternal influence on offspring in insects is not commonly observed, but illustrates the side effects of development on a transgenic plant expressing less than a high dose, 25 times the concentration needed to kill susceptible larvae. PMID:26809264

  4. Influence of Dual-Bt Protein Corn on Bollworm, Helicoverpa zea (Boddie), Survivorship on Bollgard II Cotton.

    PubMed

    Von Kanel, M B; Gore, J; Catchot, A; Cook, D; Musser, F; Caprio, M

    2016-04-01

    Similar Cry proteins are expressed in both Bt corn, Zea mays L., and cotton, Gossypium hirsutum (L.), commercial production systems. At least one generation of corn earworm, Helicoverpa zea (Boddie), completes development on field corn in the Mid-South before dispersing across the landscape into other crop hosts like cotton. A concern is that Bt corn hybrids may result in selection for H. zea populations with a higher probability of causing damage to Bt cotton. The objective of this study was to determine the susceptibility of H. zea offspring from moths that developed on non-Bt and VT Triple Pro (VT3 PRO) field corn to lyophilized Bollgard II cotton tissue expressing Cry1Ac and Cry2Ab. Offspring of individuals reared on VT3 PRO expressing Cry1A.105 and Cry2Ab had a significantly higher LC50 two out of the three years this study was conducted. Excess larvae were placed on artificial diet and allowed to pupate to determine if there were any inheritable fitness costs associated with parental development on VT3 PRO corn. Offspring resulting from males collected from VT3 PRO had significantly lower pupal weight and longer pupal duration compared with offspring of individuals collected from non-Bt corn. However, offspring from females collected from VT3 PRO were not different from non-Bt offspring. Paternal influence on offspring in insects is not commonly observed, but illustrates the side effects of development on a transgenic plant expressing less than a high dose, 25 times the concentration needed to kill susceptible larvae. PMID:26809264

  5. Frequency of Bt resistance alleles in Helicoverpa armigera in the Xinjiang cotton-planting region of China.

    PubMed

    Li, Guoping; Feng, Hongqiang; Gao, Yulin; Wyckhuys, Kris A G; Wu, Kongming

    2010-10-01

    Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) is a key insect pest of cotton in Xinjiang cotton-planting region of northwest China. In this region, cotton is grown on average ≈ 1.65 million ha (1.53 ≈ 1.80 million ha) annually in largely monoculture agricultural landscapes, similarly to cropping systems in the United States or Australia. Under such cropping regimes, naturally occurring refuges (with non-Bt crops) may be insufficient to prevent H. armigera resistance development to Bt toxins. Therefore, we assessed frequency of alleles conferring resistance to Cry1Ac toxin of F(1) and F(2) offspring of H. armigera isofemale lines from two distinct localities in the region during 2005-2009. More specifically, a total of 224 isofemale lines was collected from Korla County (≈ 70% Bt cotton adoption) and 402 lines from Shache County (≈ 5% Bt cotton planting). Subsequent offspring was screened on Cry1Ac artificial diet. From 2005 to 2009, resistance gene frequency in Korla fluctuated between 0.0000 and 0.0040, while being 0.0000-0.0008 in individuals collected from Shache, and there were no significant increases in both counties from 2005 to 2009. Relative average development rates (RADRs) of larvae in F(1) tests showed significant increases from Korla, but not in Shache. RADR of F(1) larvae is significantly correlated with RADR of F(2) offspring, indicating genetic variation in response to toxin in field H. armigera population. Although the occurrence of Cry1Ac resistance alleles was low in Xinjiang cotton-planting region of China, particular attention should be given to H. armigera resistance development in Korla County. PMID:22546469

  6. Influence of one or two Bt genes transgenic cotton free living nitrogen fixers and p-solubilising microorganisms in vertisols and alfisols

    NASA Astrophysics Data System (ADS)

    Sudha, T.; Babu, R.; Biradar, D. P.; Patil, V. C.; Shirnalli, G.

    2012-04-01

    India, the largest cotton grower in the world benefited from the cultivation of genetically modified Bt transgenic cotton. Bt cotton with the single gene (cry 1Ac) contributed to increased productivity over the last eight years. But in the recent years, there has been an increasing trend to adopt two genes (cry 1Ac and cry 2Ab) transgenic cotton in India. The two gene Bt cotton hybrids were planted over a large area (57%) during 2009 than the single gene Bt cotton hybrids. In this context, the field experiments were conducted in farmers field in both Vertisols and Alfisols during monsoon season of 2009 to study the effect of a single gene Bt hybrid (RCH-2Bt, JK-99Bt, Mallika Bt, MRC-6918 Bt, Brahma Bt, RCH-708 Bt, Bunny Bt) as well as two gene Bt hybrids (RCH-2 BGII Bt, Bunny BGII Bt) compared with the non genetically modified (non-Bt) hybrid (DHH-11) on the population of free living nitrogen fixing microorganisms (Azospirillum and methylotrophs) and P-solubilizers in two different soil types under rainfed situation. Observations on microbial population were recorded at flowering and at harvest in both the soil types. Results indicated a higher population of Azospirillum, methylotrophs and P-solubilisers in the rhizosphere grown with single or two gene Bt hybrid and non-Bt hybrid at flowering stage in both the soil types. In Vertisol, significantly higher population of methylotrophs in MRC-6918 Bt (30 x 102/g of soil), P-solubilizers in RCH-2 Bt (31x103/g of soil) and Azospirillum in RCH-708 Bt (0.79 x 106 /g of soil) was recorded as compared to non-Bt hybrid DHH-11 (2 x 102/g of soil, 12 x 103/g of soil, 0.54 x 106/g of soil), respectively. Whereas, in Alfisol, significantly higher population of methylotrophs in RCH-2 Bt (13x 102/g of soil), P-solubilisers in JK-99 Bt (38 x 103/g of soil) and Azospirillum in RCH-2Bt (0.57 x 106/g of soil) was recorded over non Bt hybrid DHH-11 (2x 102/g of soil, 13x 103/g of soil and 0.17 x106/g of soil) respectively. Our results

  7. Transgenic Bt cotton driven by the green tissue-specific promoter shows strong toxicity to lepidopteran pests and lower Bt toxin accumulation in seeds.

    PubMed

    Wang, Qing; Zhu, Yi; Sun, Lin; Li, Lebin; Jin, Shuangxia; Zhang, Xianlong

    2016-02-01

    A promoter of the PNZIP (Pharbitis nil leucine zipper) gene (1.459 kb) was cloned from Pharbitis nil and fused to the GUS (β-glucuronidase) and Bacillus thuringiensis endotoxin (Cry9C) genes. Several transgenic PNZIP::GUS and PNZIP::Cry9C cotton lines were developed by Agrobacterium-mediated transformation. Strong GUS staining was detected in the green tissues of the transgenic PNZIP::GUS cotton plants. In contrast, GUS staining in the reproductive structures such as petals, anther, and immature seeds of PNZIP::GUS cotton was very faint. Two transgenic PNZIP::Cry9C lines and one transgenic cauliflower mosaic virus (CaMV) 35S::Cry9C line were selected for enzyme-linked immunosorbent assay (ELISA) and insect bioassays. Expression of the Cry9C protein in the 35S::Cry9C line maintained a high level in most tissues ranging from 24.6 to 45.5 μg g(-1) fresh weight. In green tissues such as the leaves, boll rinds, and bracts of the PNZIP::Cry9C line, the Cry9C protein accumulated up to 50.2, 39.7, and 48.3 μg g(-1) fresh weight respectively. In contrast, seeds of the PNZIP::Cry9C line (PZ1.3) accumulated only 0.26 μg g(-1) fresh weight of the Cry9C protein, which was 100 times lower than that recorded for the seeds of the CaMV 35S::Cry9C line. The insect bioassay showed that the transgenic PNZIP::Cry9C cotton plant exhibited strong resistance to both the cotton bollworm and the pink bollworm. The PNZIP promoter could effectively drive Bt toxin expression in green tissues of cotton and lower accumulated levels of the Bt protein in seeds. These features should allay public concerns about the safety of transgenic foods. We propose the future utility of PNZIP as an economical, environmentally friendly promoter in cotton biotechnology. PMID:26728504

  8. Non-Recessive Bt Toxin Resistance Conferred by an Intracellular Cadherin Mutation in Field-Selected Populations of Cotton Bollworm

    PubMed Central

    Zhang, Haonan; Wu, Shuwen; Yang, Yihua; Tabashnik, Bruce E.; Wu, Yidong

    2012-01-01

    Transgenic crops producing Bacillus thuringiensis (Bt) toxins have been planted widely to control insect pests, yet evolution of resistance by the pests can reduce the benefits of this approach. Recessive mutations in the extracellular domain of toxin-binding cadherin proteins that confer resistance to Bt toxin Cry1Ac by disrupting toxin binding have been reported previously in three major lepidopteran pests, including the cotton bollworm, Helicoverpa armigera. Here we report a novel allele from cotton bollworm with a deletion in the intracellular domain of cadherin that is genetically linked with non-recessive resistance to Cry1Ac. We discovered this allele in each of three field-selected populations we screened from northern China where Bt cotton producing Cry1Ac has been grown intensively. We expressed four types of cadherin alleles in heterologous cell cultures: susceptible, resistant with the intracellular domain mutation, and two complementary chimeric alleles with and without the mutation. Cells transfected with each of the four cadherin alleles bound Cry1Ac and were killed by Cry1Ac. However, relative to cells transfected with either the susceptible allele or the chimeric allele lacking the intracellular domain mutation, cells transfected with the resistant allele or the chimeric allele containing the intracellular domain mutation were less susceptible to Cry1Ac. These results suggest that the intracellular domain of cadherin is involved in post-binding events that affect toxicity of Cry1Ac. This evidence is consistent with the vital role of the intracellular region of cadherin proposed by the cell signaling model of the mode of action of Bt toxins. Considered together with previously reported data, the results suggest that both pore formation and cell signaling pathways contribute to the efficacy of Bt toxins. PMID:23285292

  9. Evaluation of Bt-cotton Genotypes for Resistance to Cotton Leaf Curl Disease under High Inoculum Pressure in the Field and Using Graft Inoculation in Glasshouse

    PubMed Central

    Akhtar, Khalid Pervaiz; Hussain, Manzoor; Mahmood-Ul-Hassan; Sarwar, Muhammad; Sarwar, Nighat

    2015-01-01

    Bt-cotton germplasm, consisting of 75 genotypes was evaluated against cotton leaf curl disease (CLCuD) under high inoculum pressure in the field and using graft inoculation in glasshouse by visual symptom scoring assessments. None of the tested genotype was found disease free under both evaluation tests. Under field conditions in 2011, 3 genotypes were found resistant, 4 moderately resistant, 3 tolerant, 2 moderately susceptible and one susceptible; in 2012, 3 genotypes were tolerant, 7 moderately susceptible, 5 susceptible and 38 highly susceptible; in 2013, one was moderately susceptible and 51 were highly susceptible with varying degree of percent disease index (PDI) and severity index (SI). However, through graft evaluation in glasshouse, none of the graft inoculated plant was symptomless. All tested genotypes showed disease symptoms with SI values ranging between 5.0 and 6.0, and latent period between 12 and 14 days. Of the 75 genotypes evaluated using graft inoculation, 11 were found susceptible with SI values of 5.0 to 5.4 while remaining 64 were highly susceptible with SI values of 5.5 to 6.0. Inoculated plants of all tested genotypes exhibited severe disease symptoms within 10 days after the appearance of initial symptoms. No reduction in SI value was observed until the end of the experiment i.e., 90 days after grafting. Information generated under the present study clearly demonstrates that no sources of resistance to CLCuD are available among the tested Bt-cotton genotypes. So, a breeding programme is needed to introgress the CLCuD-resistance from other resistant sources to agronomically suitable Bt-cotton genotypes. PMID:26060432

  10. Economic comparisons of Bt and non-Bt cotton under different insecticide regimens in the MS Delta

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since the introduction of the first transgenic cotton for the control of caterpillar pests, Bollgard®, in 1996, there has been interest in evaluating the cost of control and the resulting yields of these transgenic traits in both sprayed and unsprayed environments. During the 2011 growing season, f...

  11. Multi-toxin resistance enables pink bollworm survival on pyramided Bt cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transgenic crops producing Bacillus thuringiensis (Bt) proteins kill key insect pests, providing economic and environmental benefits. However, the evolution of pest resistance threatens the continued success of such Bt crops. To delay or counter resistance, transgenic plant "pyramids" producing tw...

  12. Survival and Development of Spodoptera frugiperda and Chrysodeixis includens (Lepidoptera: Noctuidae) on Bt Cotton and Implications for Resistance Management Strategies in Brazil.

    PubMed

    Sorgatto, Rodrigo J; Bernardi, Oderlei; Omoto, Celso

    2015-02-01

    In Brazil, Spodoptera frugiperda (J. E. Smith) and Chrysodeixis includens (Walker) are important cotton pests and target of control of Bollgard II (Cry1Ac/Cry2Ab2) and WideStrike (Cry1Ac/Cry1F) cotton technologies. To subsidize an insect resistance management program, we conducted laboratory studies to evaluate the toxicity of these Bt cotton plants throughout larval development of S. frugiperda and C. includens. In bioassays with leaf disc, the efficacy of both Bt cotton plants against neonates was >80% for S. frugiperda and 100% for C. includens. However, S. frugiperda larvae that survived on Bt cotton had >76% of growth inhibition and stunting. In bioassays with S. frugiperda and C. includens larvae fed on non-Bt near-isoline during different time period (from 3 to 18 d) and then transferred to Bollgard II or WideStrike leaves showed that larval susceptibility decreased as larval age increased. For Bollgard II cotton, in all S. frugiperda instars, there were larvae that reached the pupal and adult stages. In contrast, on WideStrike cotton, a few larvae in fifth and sixth instar completed the biological cycle. For C. includens, some larvae in sixth instar originated adults in both Bt cotton plants. In conclusion, Bollgard II and WideStrike cotton technologies showed high efficacy against neonates of S. frugiperda and C. includens. However, the mortality of these species decreases as larval age increase, allowing insect survival in a possible seed mixture environment and favoring the resistance evolution. PMID:26308821

  13. A Comprehensive Assessment of the Effects of Bt Cotton on Coleomegilla maculata Demonstrates No Detrimental Effects by Cry1Ac and Cry2Ab

    PubMed Central

    Li, Yunhe; Romeis, Jörg; Wang, Ping; Peng, Yufa; Shelton, Anthony M.

    2011-01-01

    The ladybird beetle, Coleomegilla maculata (DeGeer), is a common and abundant predator in many cropping systems. Its larvae and adults are predaceous, feeding on aphids, thrips, lepidopteran larvae and plant tissues, such as pollen. Therefore, this species is exposed to insecticidal proteins expressed in insect-resistant, genetically engineered cotton expressing Cry proteins derived from Bacillus thuringiensis (Bt). A tritrophic bioassay was conduced to evaluate the potential impact of Cry2Ab- and Cry1Ac-expressing cotton on fitness parameters of C. maculata using Bt-susceptible and -resistant larvae of Trichoplusia ni as prey. Coleomegilla maculata survival, development time, adult weight and fecundity were not different when they were fed with resistant T. ni larvae reared on either Bt or control cotton. To ensure that C. maculata were not sensitive to the tested Cry toxins independent from the plant background and to add certainty to the hazard assessment, C. maculata larvae were fed artificial diet incorporated with Cry2Ab, Cry1Ac or both at >10 times higher concentrations than in cotton tissue. Artificial diet containing E-64 was included as a positive control. No differences were detected in any life-table parameters between Cry protein-containing diet treatments and the control diet. In contrast, larvae of C. maculata fed the E-64 could not develop to the pupal stage and the 7-d larval weight was significantly negatively affected. In both feeding assays, the stability and bioactivity of Cry proteins in the food sources were confirmed by ELISA and sensitive-insect bioassays. Our results show that C. maculata is not affected by Bt cotton and is not sensitive to Cry2Ab and Cry1Ac at concentrations exceeding the levels in Bt cotton, thus demonstrating that Bt cotton will pose a negligible risk to C. maculata. More importantly, this study demonstrates a comprehensive system for assessing the risk of genetically modified plants on non-target organisms. PMID

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

    PubMed Central

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

    2016-01-01

    Transgenic crops producing Bacillus thuringiensis (Bt) proteins have become a primary tool in pest management. Due to the intensive use of Bt crops, resistance of the fall armyworm, Spodoptera frugiperda, to Cry1F maize has occurred in Puerto Rico, Brazil, and some areas of the southeastern U.S. The sustainability of Bt crops faces a great challenge because the Cry1F-maize resistant S. frugiperda may also infest other Bt crops in multiple cropping ecosystems. Here we examined the survival and plant injury of a S. frugiperda population selected with Cry1F maize on three single-gene and five pyramided Bt cotton products. Larvae of Cry1F-susceptible (SS), -heterozygous (RS), and -resistant (RR) genotypes of S. frugiperda were all susceptible to the pyramided cotton containing Cry1Ac/Cry2Ab, Cry1Ac/Cry1F/Vip3A, Cry1Ab/Cry2Ae, or Cry1Ab/Cry2Ae/Vip3A, and the single-gene Cry2Ae cotton. Pyramided cotton containing Cry1Ac/Cry1F was effective against SS and RS, but not for RR. These findings show that the Cry1F-maize selected S. frugiperda can cause cross-crop resistance to other Bt crops expressing similar insecticidal proteins. Resistance management and pest management programs that utilize diversify mortality factors must be implemented to ensure the sustainability of Bt crops. This is especially important in areas where resistance to single-gene Bt crops is already widespread. PMID:27301612

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

    PubMed

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

    2016-01-01

    Transgenic crops producing Bacillus thuringiensis (Bt) proteins have become a primary tool in pest management. Due to the intensive use of Bt crops, resistance of the fall armyworm, Spodoptera frugiperda, to Cry1F maize has occurred in Puerto Rico, Brazil, and some areas of the southeastern U.S. The sustainability of Bt crops faces a great challenge because the Cry1F-maize resistant S. frugiperda may also infest other Bt crops in multiple cropping ecosystems. Here we examined the survival and plant injury of a S. frugiperda population selected with Cry1F maize on three single-gene and five pyramided Bt cotton products. Larvae of Cry1F-susceptible (SS), -heterozygous (RS), and -resistant (RR) genotypes of S. frugiperda were all susceptible to the pyramided cotton containing Cry1Ac/Cry2Ab, Cry1Ac/Cry1F/Vip3A, Cry1Ab/Cry2Ae, or Cry1Ab/Cry2Ae/Vip3A, and the single-gene Cry2Ae cotton. Pyramided cotton containing Cry1Ac/Cry1F was effective against SS and RS, but not for RR. These findings show that the Cry1F-maize selected S. frugiperda can cause cross-crop resistance to other Bt crops expressing similar insecticidal proteins. Resistance management and pest management programs that utilize diversify mortality factors must be implemented to ensure the sustainability of Bt crops. This is especially important in areas where resistance to single-gene Bt crops is already widespread. PMID:27301612

  16. Effects of Transgenic Bt Cotton on Insecticide Use and Predatory Insect Abundance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Considerable effort has been expended to determine if crops genetically engineered to produce Bacillus thuringiensis (Bt) toxins harm non-target arthropods. However, if Bt crops kill target pests and thereby reduce insecticide use, this could benefit some non-target arthropods. We analyzed data fr...

  17. Yield response of dual-toxin Bt cotton to Helicoverpa zea infestations.

    PubMed

    Gore, J; Adamczyk, J J; Catchot, A; Jackson, R

    2008-10-01

    Field cage experiments were conducted to determine the impact of bollworms, Helicoverpa zea (Boddie), on yields of Bollgard II and Widestrike cotton, Gossypium hirsutum L. One-day-old bollworm larvae were infested in white flowers of Bollgard II and in white flowers and terminals of Widestrike cotton. The infestation levels included 0, 50, and 100% of white flowers for each type of cotton. Terminal infestations included one or two larvae per terminal on Widestrike cotton. Larvae were placed in flowers of Bollgard II cotton each day for 1 to 4 wk during the first 4 wk of flowering during 2003, 2004, and 2005 seasons and in the flowers or terminals of Widestrike cotton each day for 1 to 3 wk. Averaged across years and durations of infestation, yields of Bollgard II cotton were significantly reduced compared with noninfested Bollgard II cotton when 100% of white flowers were infested. For Widestrike cotton, there was a reduction in yield when 100% of white flowers were infested in 2005, but not in 2006. There was a significant relationship for cumulative numbers of white flowers infested on seedcotton yield of Bollgard II during one of the 3 yr of the experiment. The regression equation during that year had a slope of -0.77. No significant relationships were observed for cumulative numbers of white flowers infested on yields of Widestrike cotton. Results of the current experiment suggest bollworms will rarely cause yield losses of Bollgard II and Widestrike cotton. Future research will need to focus on developing specific thresholds for bollworms on Bollgard II and Widestrike cotton. PMID:18950041

  18. Adaptive management of pest resistance by Helicoverpa species (Noctuidae) in Australia to the Cry2Ab Bt toxin in Bollgard II® cotton

    PubMed Central

    Downes, Sharon; Mahon, Rodney J; Rossiter, Louise; Kauter, Greg; Leven, Tracey; Fitt, Gary; Baker, Geoff

    2010-01-01

    In Australia, monitoring Helicoverpa species for resistance to the Cry2Ab toxin in second generation Bacillus thuringiensis (Bt) cotton has precisely fulfilled its intended function: to warn of increases in resistance frequencies that may lead to field failures of the technology. Prior to the widespread adoption of two-gene Bt cotton, the frequency of Cry2Ab resistance alleles was at least 0.001 in H. armigera and H. punctigera. In the 5 years hence, there has been a significant and apparently exponential increase in the frequency of alleles conferring Cry2Ab resistance in field populations of H. punctigera. Herein we review the history of deploying and managing resistance to Bt cotton in Australia, outline the characteristics of the isolated resistance that likely impact on resistance evolution, and use a simple model to predict likely imminent resistance frequencies. We then discuss potential strategies to mitigate further increases in resistance frequencies, until the release of a third generation product. These include mandating larger structured refuges, applying insecticide to crops late in the season, and restricting the area of Bollgard II® cotton. The area planted to Bt-crops is anticipated to continue to rise worldwide; therefore the strategies being considered in Australia are likely to relate to other situations. PMID:25567948

  19. Adaptive management of pest resistance by Helicoverpa species (Noctuidae) in Australia to the Cry2Ab Bt toxin in Bollgard II® cotton.

    PubMed

    Downes, Sharon; Mahon, Rodney J; Rossiter, Louise; Kauter, Greg; Leven, Tracey; Fitt, Gary; Baker, Geoff

    2010-09-01

    In Australia, monitoring Helicoverpa species for resistance to the Cry2Ab toxin in second generation Bacillus thuringiensis (Bt) cotton has precisely fulfilled its intended function: to warn of increases in resistance frequencies that may lead to field failures of the technology. Prior to the widespread adoption of two-gene Bt cotton, the frequency of Cry2Ab resistance alleles was at least 0.001 in H. armigera and H. punctigera. In the 5 years hence, there has been a significant and apparently exponential increase in the frequency of alleles conferring Cry2Ab resistance in field populations of H. punctigera. Herein we review the history of deploying and managing resistance to Bt cotton in Australia, outline the characteristics of the isolated resistance that likely impact on resistance evolution, and use a simple model to predict likely imminent resistance frequencies. We then discuss potential strategies to mitigate further increases in resistance frequencies, until the release of a third generation product. These include mandating larger structured refuges, applying insecticide to crops late in the season, and restricting the area of Bollgard II® cotton. The area planted to Bt-crops is anticipated to continue to rise worldwide; therefore the strategies being considered in Australia are likely to relate to other situations. PMID:25567948

  20. PINK BOLLWORM AND CABBAGE LOOPER MORTALITIES AND NUCOTN 33B (BT) CRY1AC CONTENTS IN COTTON FRUITING FORMS AND LEAVES ON INCREASING NUMBERS OF DAYS AFTER PLANTING

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Studies were conducted to follow seasonal susceptibility of feral pink bollworm (PBW), Pectinophora gossypiella (Saunders) larvae to NuCOTN 33B (Bt) and Deltapine (DPL) 5414 in furrow and furrow plus supplementary drip-irrigated cotton field plots. Laboratory bioassays of laboratory - reared PBW la...

  1. Update on monitoring of resistance to Bt cotton in key lepidopteran pests in the USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Producers sprayed more Bollgard II to control target lepidopteran pests in 2010 than in previous years, and therefore concerns have been expressed that the susceptibility of the target lepidopteran pests to the Bt Cry1Ac and Cry2Ab proteins in Bollgard II has significantly decreased. However, resist...

  2. Alternative Splicing and Highly Variable Cadherin Transcripts Associated with Field-Evolved Resistance of Pink Bollworm to Bt Cotton in India

    PubMed Central

    Fabrick, Jeffrey A.; Ponnuraj, Jeyakumar; Singh, Amar; Tanwar, Raj K.; Unnithan, Gopalan C.; Yelich, Alex J.; Li, Xianchun; Carrière, Yves; Tabashnik, Bruce E.

    2014-01-01

    Evolution of resistance by insect pests can reduce the benefits of insecticidal proteins from Bacillus thuringiensis (Bt) that are used extensively in sprays and transgenic crops. Despite considerable knowledge of the genes conferring insect resistance to Bt toxins in laboratory-selected strains and in field populations exposed to Bt sprays, understanding of the genetic basis of field-evolved resistance to Bt crops remains limited. In particular, previous work has not identified the genes conferring resistance in any cases where field-evolved resistance has reduced the efficacy of a Bt crop. Here we report that mutations in a gene encoding a cadherin protein that binds Bt toxin Cry1Ac are associated with field-evolved resistance of pink bollworm (Pectinophora gossypiella) in India to Cry1Ac produced by transgenic cotton. We conducted laboratory bioassays that confirmed previously reported resistance to Cry1Ac in pink bollworm from the state of Gujarat, where Bt cotton producing Cry1Ac has been grown extensively. Analysis of DNA from 436 pink bollworm from seven populations in India detected none of the four cadherin resistance alleles previously reported to be linked with resistance to Cry1Ac in laboratory-selected strains of pink bollworm from Arizona. However, DNA sequencing of pink bollworm derived from resistant and susceptible field populations in India revealed eight novel, severely disrupted cadherin alleles associated with resistance to Cry1Ac. For these eight alleles, analysis of complementary DNA (cDNA) revealed a total of 19 transcript isoforms, each containing a premature stop codon, a deletion of at least 99 base pairs, or both. Seven of the eight disrupted alleles each produced two or more different transcript isoforms, which implicates alternative splicing of messenger RNA (mRNA). This represents the first example of alternative splicing associated with field-evolved resistance that reduced the efficacy of a Bt crop. PMID:24840729

  3. Bt proteins Cry1Ah and Cry2Ab do not affect cotton aphid Aphis gossypii and ladybeetle Propylea japonica

    PubMed Central

    Zhao, Yao; Zhang, Shuai; Luo, Jun-Yu; Wang, Chun-Yi; Lv, Li-Min; Wang, Xiao-Ping; Cui, Jin-Jie; Lei, Chao-Liang

    2016-01-01

    Plant varieties expressing the Bt (Bacillus thuringiensis) insecticidal proteins Cry1Ah and Cry2Ab have potential commercialization prospects in China. However, their potential effects on non-target arthropods (NTAs) remain uncharacterized. The cotton aphid Aphis gossypii is a worldwide pest that damages various important crops. The ladybeetle Propylea japonica is a common and abundant natural enemy in many cropping systems in East Asia. In the present study, the effects of Cry1Ah and Cry2Ab proteins on A. gossypii and P. japonica were assessed from three aspects. First, neither of the Cry proteins affected the growth or developmental characteristics of the two test insects. Second, the expression levels of the detoxification-related genes of the two test insects did not change significantly in either Cry protein treatment. Third, neither of the Cry proteins had a favourable effect on the expression of genes associated with the amino acid metabolism of A. gossypii and the nutrition utilization of P. japonica. In conclusion, the Cry1Ah and Cry2Ab proteins do not appear to affect the cotton aphid A. gossypii or the ladybeetle P. japonica. PMID:26829252

  4. Bt proteins Cry1Ah and Cry2Ab do not affect cotton aphid Aphis gossypii and ladybeetle Propylea japonica.

    PubMed

    Zhao, Yao; Zhang, Shuai; Luo, Jun-Yu; Wang, Chun-Yi; Lv, Li-Min; Wang, Xiao-Ping; Cui, Jin-Jie; Lei, Chao-Liang

    2016-01-01

    Plant varieties expressing the Bt (Bacillus thuringiensis) insecticidal proteins Cry1Ah and Cry2Ab have potential commercialization prospects in China. However, their potential effects on non-target arthropods (NTAs) remain uncharacterized. The cotton aphid Aphis gossypii is a worldwide pest that damages various important crops. The ladybeetle Propylea japonica is a common and abundant natural enemy in many cropping systems in East Asia. In the present study, the effects of Cry1Ah and Cry2Ab proteins on A. gossypii and P. japonica were assessed from three aspects. First, neither of the Cry proteins affected the growth or developmental characteristics of the two test insects. Second, the expression levels of the detoxification-related genes of the two test insects did not change significantly in either Cry protein treatment. Third, neither of the Cry proteins had a favourable effect on the expression of genes associated with the amino acid metabolism of A. gossypii and the nutrition utilization of P. japonica. In conclusion, the Cry1Ah and Cry2Ab proteins do not appear to affect the cotton aphid A. gossypii or the ladybeetle P. japonica. PMID:26829252

  5. Effects of Bt cotton on Thrips tabaci and its predator, Orius insidiosus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Laboratory studies were conducted to investigate tritrophic transfer of insecticidal Cry proteins from transgenic cotton to a herbivore and its predator, and to examine effects of these proteins on the predator’s development, survival and reproduction. Cry1Ac and Cry2Ab proteins from the bacterium ...

  6. Reduced foliage herbivory in Bt cotton benefits phloem-feeding insects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetically modified cotton plants that express Lepidoptera-active toxins from Bacillus thuringiensis are grown on 15.5 millions hectares worldwide. Numerous studies have established that these plants pose a negligible risk to non-target arthropods due to the narrow spectrum of activity of the expre...

  7. Activation of Bt Protoxin Cry1Ac in Resistant and Susceptible Cotton Bollworm

    PubMed Central

    Liang, Gemei; Wang, Bingjie; Zhong, Feng; Chen, Lin; Khaing, Myint Myint; Zhang, Jie; Guo, Yuyuan; Wu, Kongming; Tabashnik, Bruce E.

    2016-01-01

    Crystalline (Cry) proteins from Bacillus thuringiensis (Bt) are used extensively for insect control in sprays and transgenic plants, but their efficacy is reduced by evolution of resistance in pests. Here we evaluated reduced activation of Cry1Ac protoxin as a potential mechanism of resistance in the invasive pest Helicoverpa armigera. Based on the concentration killing 50% of larvae (LC50) for a laboratory-selected resistant strain (LF120) divided by the LC50 for its susceptible parent strain (LF), the resistance ratio was 1600 for Cry1Ac protoxin and 1200 for trypsin-activated Cry1Ac toxin. The high level of resistance to activated toxin as well as to protoxin indicates reduced activation of protoxin is not a major mechanism of resistance to Cry1Ac in LF120. For both insect strains, treatment with either the trypsin inhibitor N-a-tosyl-L-lysine chloromethyl ketone (TLCK) or the chymotrypsin inhibitor N-a-tosyl-L-phenylalanine chloromethyl ketone (TPCK) did not significantly affect the LC50 of Cry1Ac protoxin. Enzyme activity was higher for LF than LF120 for trypsin-like proteases, but did not differ between strains for chymotrypsin-like proteases. The results here are consistent with previous reports indicating that reduced activation of protoxin is generally not a major mechanism of resistance to Bt proteins. PMID:27257885

  8. Efficacy evaluation of selected herbicides on weed control and productivity evaluation of Bt cotton in Punjab.

    PubMed

    Singh, Kulvir; Rathore, Pankaj

    2015-07-01

    Field experiments were conducted during Kharif 2012 and 2013 to evaluate the efficacy of different herbicides for weed management in cotton. Highest seed cotton yield (3537.3 kg ha(-1)) was recorded in weed free plots followed by pendimethalin @1.0 kg a.i ha(-1) as Pre.em.+quizalofopethyl @50 g a.i ha(-1) post-em at 2-4 weed leaf stage + one hoeing (3318.9 kg ha") owing to improved number of bolls per plant and boll weight. Statistically least yield was recorded underweedy check (1435.4 kg ha(-1)). Application of pyrithiobac sodium could not express any visible toxic effect on crop indicating its selectivity for cotton, although none of the tested new chemicals i.e., pyrithiobac sodium@ 62.5g a.i ha(-1) and quizalofopethyl @50g a.i ha(-1) when applied alone could not outperform the existing recommended chemicals for weed management. Yield losses to the extent of 6.2-59.4% were recorded due to weed competition. Weed control efficiency (WCE) was highest under weed free check (86.8%) followed by pendimethalin @1.0 kg a.i ha(-1) as Pre. em.+quizalofopethyl @50g a.i ha(-1), at 2-4 weed leaf stage + one hoeing (73.7%), whereas minimum values were for weedy check (24.7%). Though net returns (r94660 ha(-1)) were highest for weed free check but higher B:C ratio (2:11) was observed for pendimethalin @1.0 kg a.i ha(-1) as Pre em.+quizalofopethyl @50 g a.i ha(-1) post-em at 2-4 weed leaf stage+one hoeing. Therefore, for reasons such as labor shortage besides their timely availability, using these herbicides in combination with cultural practices could be the practical solution foreconomically efficient and effective weed management. PMID:26364480

  9. Mosquito Larvicidal Potential of Gossypium hirsutum (Bt cotton) Leaves Extracts against Aedes aegypti and Anopheles stephensi larvae

    PubMed Central

    Patil, Chandrashekhar D; Borase, Hemant P; Salunkhe, Rahul B; Suryawanshi, Rahul K; Narkhade, Chandrakant P; Salunke, Bipinchandra K; Patil, Satish V

    2014-01-01

    Background: We aimed to extract the ingredients from leaves of Gossypium hirsutum (Bt cotton) using different solvents and evaluate for potential use to control different larval stages of mosquito species, Aedes aegypti and Anopheles stephensi. Methods: Qualitative and quantitative estimation of ingredients from Go. hirsutum (Bt) plant extract was carried out and their inhibitory action against mosquito larvae was determined using mosquito larvicidal assay. Results: LC50 values of water, ethanol, ethyl acetate and hexane extracts for Ae. aegypti were 211.73±21.49, 241.64±19.92, 358.07±32.43, 401.03±36.19 and 232.56±26.00, 298.54±21.78, 366.50±30.59, 387.19±31.82 for 4th instar of An. stephensi, respectively. The water extract displayed lowest LC50 value followed by ethanol, ethyl acetate and hexane. Owing to the comparatively better activity of water extract, its efficacy was further evaluated for mosquito larvicidal activity, which exhibited LC50 values of 133.95±12.79, 167.65±11.34 against 2nd and 3rd instars of Ae. aegypti and 145.48±11.76, 188.10±12.92 against 2nd and 3rd instars of An. stephensi, respectively. Crude protein from the water extract was precipitated using acetone and tested against 2nd, 3rd and 4th instars of Ae. aegypti and An. stephensi. It revealed further decrease in LC50 values as 105.72±25.84, 138.23±23.18, 126.19±25.65, 134.04±04 and 137.88±17.59, 154.25±16.98 for 2nd, 3rd and 4th instars of Ae. aegypti and An. stephensi, respectively. Conclusion: Leaves extracts of Go. hirsutum (Bt) is potential mosquito larvicide and can be used as a potent alternative to chemical insecticides in integrated pest management. PMID:25629069

  10. Cis-mediated down-regulation of a trypsin gene associated with Bt resistance in cotton bollworm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transgenic plants producing insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) are useful for pest control, but their efficacy is reduced when pests evolve resistance. Previously identified mechanisms of resistance to Bt toxins include reduced binding of activated Bt toxins to m...

  11. Capturing the interaction types of two Bt toxins Cry1Ac and Cry2Ab on suppressing the cotton bollworm by using multi-exponential equations.

    PubMed

    Shi, Pei-Jian; Wei, Ji-Zhen; Sandhu, Hardev S; Liang, Ge-Mei

    2016-08-01

    Transgenic crops are increasingly promoted for their practical effects on suppressing certain insect pests, but all transgenic crops are not equally successful. The insect pests can easily develop resistance against single Bacillus thuringiensis (Bt) toxin transgenic crops. Therefore, transgenic crops including two or more mixed Bt-toxins can solve this problem by delaying the resistance development and killing the majority of targeted pests before the evolution of resistance. It is important to test the controlling effects of transgenic crops including multiple mixed toxins on a particular insect pest. Previous research has checked the cross-resistance and interactions between Bt toxins Cry1Ac and Cry2Ab against one susceptible and four resistant strains of cotton bollworm. The results showed that independence was the main interaction type between two toxins for the susceptible strain, whereas synergism was the main interaction type for any one resistant strain. However, the optimal combinations of two toxins were not obtained. In the present study, we developed two multi-exponential equations (namely bi- and tri-exponential equations) to describe the combination effects of two Bt toxins. Importantly, the equations can provide predictions of combination effects of different continuous concentrations of two toxins. We compared these two multi-exponential equations with the generalized linear model (GLM) in describing the combination effects, and found that the bi- and tri-exponential equations are better than GLM. Moreover, the bi-exponential equation can also provide the optimal dose combinations for two toxins. PMID:26314801

  12. Impact of Fall Armyworm Survival in Bt Crops on Survival and Damage Potential of Subsequent Generations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fall armyworm, Spodoptera frugiperda (J. E. Smith), colonies were compared to determine whether development on Bt corn or Bt cotton impacted survival and damage potential of subsequent generations on Bt or non-Bt cotton. Late instars of fall armyworm were collected from Bt and non-Bt sweet corn to ...

  13. Imidacloprid affects the functional response of predator Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) to strains of Spodoptera frugiperda (J.E. Smith) on Bt cotton.

    PubMed

    Malaquias, J B; Ramalho, F S; Omoto, C; Godoy, W A C; Silveira, R F

    2014-03-01

    Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) is one of the most common asopine species in the neotropical region and its occurrence was reported in several countries of South and Central America, as an important biological control agent for many crops. This study was carried out to identify the imidacloprid impacts on the functional response of predator P. nigrispinus fed on Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) strain resistant to lambda-cyhalothrin, on Bt cotton expressing Cry1Ac (Bollgard(®)). Spodoptera frugiperda larvae were used in the following conditions: resistant (1) and susceptible (2) strains to lambda-cyhalothrin fed on Bollgard(®) cotton leaves (DP 404 BG); and resistant (3) and susceptible (4) strains to lambda-cyhalothrin fed on non-genetically modified cotton leaves (cultivar DP4049). The predatory behavior of P. nigrispinus was affected by imidacloprid and the type II asymptotic curve was the one that best described the functional response data. Handling time (T h ) of predator females did not differ among treatments in the presence of imidacloprid. The attack rate did decrease, however, due to an increase in the density of larvae offered. Regardless of the treatment (S. frugiperda strain or cotton cultivar), the predation of P. nigrispinus females on S. frugiperda larvae was significantly lower when exposed to imidacloprid, especially at a density of 16 larvae/predator. The predation behavior of P. nigrispinus on S. frugiperda larvae is affected by the insecticide imidacloprid showing that its applications should be used in cotton crop with caution. PMID:24352830

  14. Outcrossed Cottonseed and Adventitious Bt Plants in Arizona Refuges

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding how transgenes enter and perpetuate in conventional fields is an important step towards reducing transgene contamination. Here we report hemizygous (Bt/non-Bt) and homozygous (Bt) cotton plants in non-Bt fields, and rogue transgenes in seed bags of conventional cotton. Our results pr...

  15. F1 Screening for Resistance Gene Alleles to Bt Cotton in Helicoverpa armigera: How to Differentiate S and R Genotypes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The F1 screening method relies on the availability in the laboratory of an insecticide-resistant insect strain that is used to detect resistance alleles at the same loci in field populations. This technique was used in this study to survey a field population of Helicoverpa armigera for Bt-resistant ...

  16. Distribution and Metabolism of Bt-Cry1Ac Toxin in Tissues and Organs of the Cotton Bollworm, Helicoverpa armigera

    PubMed Central

    Zhao, Zhuoya; Li, Yunhe; Xiao, Yutao; Ali, Abid; Dhiloo, Khalid Hussain; Chen, Wenbo; Wu, Kongming

    2016-01-01

    Crystal (Cry) proteins derived from Bacillus thuringiensis (Bt) have been widely used in transgenic crops due to their toxicity against insect pests. However, the distribution and metabolism of these toxins in insect tissues and organs have remained obscure because the target insects do not ingest much toxin. In this study, several Cry1Ac-resistant strains of Helicoverpa armigera, fed artificial diets containing high doses of Cry1Ac toxin, were used to investigate the distribution and metabolism of Cry1Ac in their bodies. Cry1Ac was only detected in larvae, not in pupae or adults. Also, Cry1Ac passed through the midgut into other tissues, such as the hemolymph and fat body, but did not reach the larval integument. Metabolic tests revealed that Cry1Ac degraded most rapidly in the fat body, followed by the hemolymph, peritrophic membrane and its contents. The toxin was metabolized slowly in the midgut, but was degraded in all locations within 48 h. These findings will improve understanding of the functional mechanism of Bt toxins in target insects and the biotransfer and the bioaccumulation of Bt toxins in arthropod food webs in the Bt crop ecosystem. PMID:27399776

  17. Distribution and Metabolism of Bt-Cry1Ac Toxin in Tissues and Organs of the Cotton Bollworm, Helicoverpa armigera.

    PubMed

    Zhao, Zhuoya; Li, Yunhe; Xiao, Yutao; Ali, Abid; Dhiloo, Khalid Hussain; Chen, Wenbo; Wu, Kongming

    2016-01-01

    Crystal (Cry) proteins derived from Bacillus thuringiensis (Bt) have been widely used in transgenic crops due to their toxicity against insect pests. However, the distribution and metabolism of these toxins in insect tissues and organs have remained obscure because the target insects do not ingest much toxin. In this study, several Cry1Ac-resistant strains of Helicoverpa armigera, fed artificial diets containing high doses of Cry1Ac toxin, were used to investigate the distribution and metabolism of Cry1Ac in their bodies. Cry1Ac was only detected in larvae, not in pupae or adults. Also, Cry1Ac passed through the midgut into other tissues, such as the hemolymph and fat body, but did not reach the larval integument. Metabolic tests revealed that Cry1Ac degraded most rapidly in the fat body, followed by the hemolymph, peritrophic membrane and its contents. The toxin was metabolized slowly in the midgut, but was degraded in all locations within 48 h. These findings will improve understanding of the functional mechanism of Bt toxins in target insects and the biotransfer and the bioaccumulation of Bt toxins in arthropod food webs in the Bt crop ecosystem. PMID:27399776

  18. Field-evolved resistance to Bt toxins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transgenic cotton expressing Bacillus thuringiensis Cry1Ac (Bt cotton) has been used commercially in the United States since 1996. An article by Tabashnik et al. 2008, Nature Biotechnology 26:199-202, states that, for the first time, there is field-evolved Bt resistance in bollworm, Helicoverpa zea...

  19. Cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton is a woody, perennial, indeterminate plant with the C3 photosynthesis pathway, that is grown in warm and some temperate climates for fiber, but also for its seed from which oil and protein are important products. Of the four cultivated forms of cotton, the dominant species in production is Go...

  20. Laboratory assessment of the impacts of transgenic Bt rice on the ecological fitness of the soil non-target arthropod, Folsomia candida (Collembola: Isotomidae).

    PubMed

    Yuan, Yiyang; Xiao, Nengwen; Krogh, Paul Henning; Chen, Fajun; Ge, Feng

    2013-08-01

    Transgenic rice expressing Bacillus thuringiensis (Bt) endotoxins (Bt rice) for pest control is considered an important solution to food security in China. However, tests for potential effects on non-target soil organisms are required for environmental risk assessment. The soil collembolan Folsomia candida L. (Collembola: Isotomidae) is a potential non-target arthropod that is often used as a biological indicator in bio-safety assessments of transgenic crops. In the present study, the roots, stems, and leaves of Bt rice were exposed to F. candida under laboratory conditions, with survival, reproduction and growth of the collembolan as ecological fitness parameters. Significant differences in ecological fitness were found among the different treatments, including differences in the plant parts and varieties of non-Bt rice, presumably as the result of three factors: gene modification, plant parts and rice varieties. The fitness of F. candida was less affected by the different diets than by the exposure to the same materials mixed with soil. Our results clearly showed that there was no negative effect of different Bt rice varieties on the fitness of F. candida through either diet or soil exposure. PMID:23322316

  1. A point mutation (L1015F) of the voltage-sensitive sodium channel gene associated with lambda-cyhalothrin resistance in Apolygus lucorum (Meyer-Dür) population from the transgenic Bt cotton field of China.

    PubMed

    Zhen, Congai; Gao, Xiwu

    2016-02-01

    In China, the green mirid bug, Apolygus lucorum (Meyer-Dür), has caused severe economic damage to many kinds of crops, especially the cotton and jujubes. Pyrethroid insecticides have been widely used for controlling this pest in the transgenic Bt cotton field. Five populations of A. lucorum collected from cotton crops at different locations in China were evaluated for lambda-cyhalothrin resistance. The results showed that only the population collected from Shandong Province exhibited 30-fold of resistance to lambda-cyhalothrin. Neither PBO nor DEF had obvious synergism when compared the synergistic ratio between SS and RR strain which was originated from the Shandong population. Besides, there were no statistically significant differences (p>0.05) in the carboxylesterase, glutathione S-transferase, or 7-ethoxycoumarin O-deethylase activities between the Shandong population and the laboratory susceptible strain (SS). The full-length sodium channel gene named AlVSSC encoding 2028 amino acids was obtained by RT-PCR and rapid amplification of cDNA ends (RACE). One single point mutation L1015F in the AlVSSC was detected only in the Shandong population. Our results revealed that the L1015F mutation associated with pyrethroid resistance was identified in A. lucorum populations in China. These results will be useful for the rational chemical control of A. lucorum in the transgenic Bt cotton field. PMID:26821662

  2. Competition among agricultural pest insects and its role in pest outbreaks associated with trasgenic Bt-cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Empirical studies on the ecological causes of agricultural pest outbreaks have focused primarily on two biotic factors—release from natural enemies and changes in host plant quality. Release from competition, on the other hand, has been theorized as a potential cause but never tested. With the exp...

  3. Food safety knowledge on the Bt mutant protein Cry8Ka5 employed in the development of coleopteran-resistant transgenic cotton plants.

    PubMed

    Farias, Davi F; Peijnenburg, Ad A C M; Grossi-de-Sá, Maria F; Carvalho, Ana F U

    2015-01-01

    Insecticidal Cry proteins from Bacillus thuringiensis (Bt) have been exploited in the development of genetically modified (GM) crops for pest control. However, several pests are still difficult to control such as the coleopteran boll weevil Anthonomus grandis. By applying in vitro molecular evolution to the cry8Ka1 gene sequence, variants were generated with improved activity against A. grandis. Among them, Cry8Ka5 mutant protein showed coleoptericidal activity 3-fold higher (LC50 2.83 μg/mL) than that of the original protein (Cry8Ka1). Cry8Ka5 has been used in breeding programs in order to obtain coleopteran-resistant cotton plants. Nevertheless, there is some concern in relation to the food safety of transgenic crops, especially to the heterologously expressed proteins. In this context, our research group has performed risk assessment studies on Cry8Ka5, using the tests recommended by Codex as well as tests that we proposed as alternative and/or complementary approaches. Our results on the risk analysis of Cry8Ka5 taken together with those of other Cry proteins, point out that there is a high degree of certainty on their food safety. It is reasonable to emphasize that most safety studies on Cry proteins have essentially used the Codex approach. However, other methodologies would potentially provide additional information such as studies on the effects of Cry proteins and derived peptides on the indigenous gastrointestinal microbiota and on intestinal epithelial cells of humans. Additionally, emerging technologies such as toxicogenomics potentially will offer sensitive alternatives for some current approaches or methods. PMID:26513483

  4. Sources, sinks, and spatial ecology of cotton mice in longleaf pine stands undergoing restoration

    USGS Publications Warehouse

    Sharp, N.W.; Mitchell, M.S.; Grand, J.B.

    2009-01-01

    The Fire and Fire Surrogate studya replicated, manipulative experimentsought the most economically and ecologically efficient way to restore the nation's fire-maintained ecosystems. As part of this study, we conducted a 3-year markrecapture study, comprising 105,000 trap-nights, to assess demographic responses of cotton mice (Peromyscus gossypinus) to Fire and Fire Surrogate treatments at the Gulf Coastal Plain site, where longleaf pine was the ecosystem to be restored. We compared competing models to evaluate restoration effects on variation in apparent survival and recruitment over time, space, and treatment, and incorporated measures of available source habitat for cotton mice with reverse-time modeling to infer immigration from outside the study area. The top-ranked survival model contained only variation over time, but the closely ranked 2nd and 3rd models included variation over space and treatment, respectively. The top 4 recruitment models all included effects for availability of source habitat and treatments. Burning appeared to degrade habitat quality for cotton mice, showing demographic characteristics of a sink, but treatments combining fire with thinning of trees or application of herbicide to the understory appeared to improve habitat quality, possibly creating sources. Bottomland hardwoods outside the study also acted as sources by providing immigrants to experimental units. Models suggested that population dynamics operated over multiple spatial scales. Treatments applied to 15-ha stands probably only caused local variation in vital rates within the larger population. ?? 2009 American Society of Mammalogists.

  5. Alternative splicing and highly variable cadherin transcripts associated with field-evolved resistance of pink bollworm to Bt cotton in India

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Evolution of resistance by insect pests can reduce the benefits of insecticidal proteins from Bacillus thuringiensis (Bt) that are used extensively in sprays and transgenic crops. Despite considerable knowledge of the genes conferring insect resistance to Bt toxins in laboratory-selected strains an...

  6. Ecology, Behavior and Bionomics: First Genotyping of Spodoptera frugiperda (J. E. Smith)(Lepidoptera: Noctuidae) Progeny from Crosses between Bt-Resistant and Bt-Susceptible Populations, and 65-Locus Discrimination of Isofami

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Simple sequence repeat (SSR) markers from Spodoptera frugiperda (J. E. Smith) were analyzed in crosses of this species between Bacillus thuringiensis (Berliner) (Bacillales: Bacillaceae) (Bt) resistant and susceptible populations to determine a possible association between markers and Bt resistance....

  7. Potential use of proteinase inhibitors and avidin for insect control and Bt resistance management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Complete Bt cotton system puts heavy selection pressure on Lepidoptera insects. Potential development of Bt resistance is major concern over Bt cotton technology. Another emerging problem is shift of pest status due to reduced number of sprays and resistance development in some sucking insects, espe...

  8. Survey of organophosphate resistance and an Ala216Ser substitution of acetylcholinesterase-1 gene associated with chlorpyrifos resistance in Apolygus lucorum (Meyer-Dür) collected from the transgenic Bt cotton fields in China.

    PubMed

    Zhen, Congai; Miao, Ling; Liang, Pei; Gao, Xiwu

    2016-09-01

    The mirid bug is frequently controlled by the application of organophosphorus insecticides in the transgenic Bt cotton field of China. A topical bioassay method was performed to evaluate the toxicities of chlorpyrifos and malathion towards field-collected Chinese populations of Apolygus lucorum from transgenic Bt cotton fields. For chlorpyrifos, the resistance ratios ranged from 0.8 to 9.4-fold compared to a susceptible strain. For malathion, the resistance levels relative to the susceptible strain ranged from 1.2 to 14.4-fold. Compared to a susceptible strain, the Cangzhou population from Hebei province showed the highest resistance ratios towards these insecticides. A comparison of the detoxifying and target enzyme activities between the Cangzhou population and a susceptible strain revealed that altered acetylcholinesterase possibly account for the chlorpyrifos and malathion resistance in the Cangzhou population. Two acetylcholinesterase (AChE-encoding) genes (designated Alace1 and Alace2) from the green mirid bug (A. lucorum) were identified. The Alace1 and Alace2 genes encoded 597 and 645 amino acids, respectively. Both AChE proteins had conserved motifs including a catalytic triad, a choline-binding site, and an acyl pocket. Quantitative real-time PCR analysis showed that Alace1 had a much higher transcriptional level than Alace2, for the expression profiles of both spatial and time distributions. One amino acid substitution, Ala216Ser in Alace1, was found in the Cangzhou population. These results suggest that the mutation Ala216Ser should be most likely involved in organophosphorus resistance in A. lucorum. PMID:27521910

  9. Orientation behavior, development and survival of Trichoplusia ni (Lepidoptera: Noctuidae) larvae on cotton expressing Cry1Ac and Cry2Ab and conventional cotton.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was conducted to determine the effects of Bt cotton (Bollgard II) or a mixture of Bt+non-Bt cotton leaves on larval orientation behavior, survival and development of Trichoplusia ni in the laboratory. Results indicate that in a no-choice test, more first and fifth instars remained on Bt...

  10. Ecological study of the larger black flour beetle in cotton gin trash.

    PubMed

    Nansen, Christian; James, Jacob; Bowling, David; Parajulee, Megha N; Porter, Patrick

    2008-12-01

    The larger black flour beetle Cynaeus angustus (Leconte) thrives in cotton gin trash piles on the Southern High Plains of Texas and sometimes becomes a nuisance after invading public and private structures. For better understanding of the basic larger black flour beetle ecology in gin trash piles, we conducted a series of laboratory and semirealistic field trials. We showed (1) in naturally infested gin trash piles, that similar trap captures were obtained in three cardinal directions; (2) in a laboratory study, late-instar larvae stayed longer in larval stage in moist soil compared with drier soil; (3) in both horizontal and vertical choice experiments, late instars preferred soil with low moisture content; and (4) specifically larger black flour beetle adults, but most larvae as well, responded negatively to high moisture content in gin trash. The results presented are consistent with reports of larger black flour beetle living in decaying yucca palms in deserts and suggest that maintaining gin trash piles with high moisture content may be an important component in an integrated control strategy. PMID:19161678

  11. Detrimental effect of expression of Bt endotoxin Cry1Ac on in vitro regeneration, in vivo growth and development of tobacco and cotton transgenics.

    PubMed

    Rawat, Preeti; Singh, Amarjeet Kumar; Ray, Krishna; Chaudhary, Bhupendra; Kumar, Sanjeev; Gautam, Taru; Kanoria, Shaveta; Kaur, Gurpreet; Kumar, Paritosh; Pental, Deepak; Burma, Pradeep Kumar

    2011-06-01

    High levels of expression of the cry1Ac gene from Bacillus thuringiensis cannot be routinely achieved in transgenic plants despite modifications made in the gene to improve its expression. This has been attributed to the instability of the transcript in a few reports. In the present study, based on the genetic transformation of cotton and tobacco, we show that the expression of the Cry1Ac endotoxin has detrimental effects on both the in vitro and in vivo growth and development of transgenic plants. A number of experiments on developing transgenics in cotton with different versions of cry1Ac gene showed that the majority of the plants did not express any Cry1Ac protein. Based on Southern blot analysis, it was also observed that a substantial number of lines did not contain the cry1Ac gene cassette although they contained the marker gene nptII. More significantly, all the lines that showed appreciable levels of expression were found to be phenotypically abnormal. Experiments on transformation of tobacco with different constructs expressing the cry1Ac gene showed that in vitro regeneration was inhibited by the encoded protein. Further, out of a total of 145 independent events generated with the different cry1Ac gene constructs in tobacco, only 21 showed expression of the Cry1Ac protein, confirming observations made in cotton that regenerants that express high levels of the Cry1Ac protein are selected against during regeneration of transformed events. This problem was circumvented by targeting the Cry1Ac protein to the chloroplast, which also significantly improved the expression of the protein. PMID:21654089

  12. Regional Assessment of Helicoverpa zea (Lepidoptera: Noctuidae) Populations on Cotton and Non-Cotton Crop Hosts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selection pressure on bollworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), by cotton, Gossypium hirsutum (L.) (Malvaceae), that produces one or more Bacillus thuringiensis (Bt) Berliner proteins is reduced by plantings of non-Bt refuge cotton that produce non-selected individuals. However, ...

  13. Current situation of pests targeted by Bt crops in Latin America.

    PubMed

    Blanco, C A; Chiaravalle, W; Dalla-Rizza, M; Farias, J R; García-Degano, M F; Gastaminza, G; Mota-Sánchez, D; Murúa, M G; Omoto, C; Pieralisi, B K; Rodríguez, J; Rodríguez-Maciel, J C; Terán-Santofimio, H; Terán-Vargas, A P; Valencia, S J; Willink, E

    2016-06-01

    Transgenic crops producing Bacillus thuringiensis- (Bt) insecticidal proteins (Bt crops) have provided useful pest management tools to growers for the past 20 years. Planting Bt crops has reduced the use of synthetic insecticides on cotton, maize and soybean fields in 11 countries throughout Latin America. One of the threats that could jeopardize the sustainability of Bt crops is the development of resistance by targeted pests. Governments of many countries require vigilance in measuring changes in Bt-susceptibility in order to proactively implement corrective measures before Bt-resistance is widespread, thus prolonging the usefulness of Bt crops. A pragmatic approach to obtain information on the effectiveness of Bt-crops is directly asking growers, crop consultants and academics about Bt-resistance problems in agricultural fields, first-hand information that not necessarily relies on susceptibility screens performed in laboratories. This type of information is presented in this report. Problematic pests of cotton and soybeans in five Latin American countries currently are effectively controlled by Bt crops. Growers that plant conventional (non-Bt) cotton or soybeans have to spray synthetic insecticides against multiple pests that otherwise are controlled by these Bt crops. A similar situation has been observed in six Latin American countries where Bt maize is planted. No synthetic insecticide applications are used to control corn pests because they are controlled by Bt maize, with the exception of Spodoptera frugiperda. While this insect in some countries is still effectively controlled by Bt maize, in others resistance has evolved and necessitates supplemental insecticide applications and/or the use of Bt maize cultivars that express multiple Bt proteins. Partial control of S. frugiperda in certain countries is due to its natural tolerance to the Bt bacterium. Of the 31 pests targeted and controlled by Bt crops in Latin America, only S. frugiperda has shown

  14. Identification of semiochemicals released by cotton, Gossypium hirsutum, upon infestation by the cotton aphid, Aphis gossypii.

    PubMed

    Hegde, Mahabaleshwar; Oliveira, Janser N; da Costa, Joao G; Bleicher, Ervino; Santana, Antonio E G; Bruce, Toby J A; Caulfield, John; Dewhirst, Sarah Y; Woodcock, Christine M; Pickett, John A; Birkett, Michael A

    2011-07-01

    The cotton aphid, Aphis gossypii (Homoptera: Aphididae), is increasing in importance as a pest worldwide since the introduction of Bt-cotton, which controls lepidopteran but not homopteran pests. The chemical ecology of interactions between cotton, Gossypium hirsutum (Malvaceae), A. gossypii, and the predatory lacewing Chrysoperla lucasina (Neuroptera: Chrysopidae), was investigated with a view to providing new pest management strategies. Behavioral tests using a four-arm (Pettersson) olfactometer showed that alate A. gossypii spent significantly more time in the presence of odor from uninfested cotton seedlings compared to clean air, but significantly less time in the presence of odor from A. gossypii infested plants. A. gossypii also spent significantly more time in the presence of headspace samples of volatile organic compounds (VOCs) obtained from uninfested cotton seedlings, but significantly less time with those from A. gossypii infested plants. VOCs from uninfested and A. gossypii infested cotton seedlings were analyzed by gas chromatography (GC) and coupled GC-mass spectrometry (GC-MS), leading to the identification of (Z)-3-hexenyl acetate, (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), methyl salicylate, and (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene (TMTT), which were produced in larger amounts from A. gossypii infested plants compared to uninfested plants. In behavioral tests, A. gossypii spent significantly more time in the control (solvent) arms when presented with a synthetic blend of these four compounds, with and without the presence of VOCs from uninfested cotton. Coupled GC-electroantennogram (EAG) recordings with the lacewing C. lucasina showed significant antennal responses to VOCs from A. gossypii infested cotton, suggesting they have a role in indirect defense and indicating a likely behavioral role for these compounds for the predator as well as the aphid. PMID:21671083

  15. Increased Frequency of Pink Bollworm Resistance to Bt Toxin Cry1Ac in China

    PubMed Central

    Wan, Peng; Huang, Yunxin; Wu, Huaiheng; Huang, Minsong; Cong, Shengbo; Tabashnik, Bruce E.; Wu, Kongming

    2012-01-01

    Transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt) kill some key insect pests, but evolution of resistance by pests can reduce their efficacy. The main approach for delaying pest adaptation to Bt crops uses non-Bt host plants as “refuges” to increase survival of susceptible pests. To delay evolution of pest resistance to transgenic cotton producing Bt toxin Cry1Ac, the United States and some other countries have required refuges of non-Bt cotton, while farmers in China have relied on “natural” refuges of non-Bt host plants other than cotton. The “natural” refuge strategy focuses on cotton bollworm (Helicoverpa armigera), the primary target of Bt cotton in China that attacks many crops, but it does not apply to another major pest, pink bollworm (Pectinophora gossypiella), which feeds almost entirely on cotton in China. Here we report data showing field-evolved resistance to Cry1Ac by pink bollworm in the Yangtze River Valley of China. Laboratory bioassay data from 51 field-derived strains show that the susceptibility to Cry1Ac was significantly lower during 2008 to 2010 than 2005 to 2007. The percentage of field populations yielding one or more survivors at a diagnostic concentration of Cry1Ac increased from 0% in 2005–2007 to 56% in 2008–2010. However, the median survival at the diagnostic concentration was only 1.6% from 2008 to 2010 and failure of Bt cotton to control pink bollworm has not been reported in China. The early detection of resistance reported here may promote proactive countermeasures, such as a switch to transgenic cotton producing toxins distinct from Cry1A toxins, increased planting of non-Bt cotton, and integration of other management tactics together with Bt cotton. PMID:22238687

  16. Increasing the cotton yield and improving the ecology in cotton fields by utilizing the properties of natural resources in Xinjiang, China

    NASA Astrophysics Data System (ADS)

    Tian, Changyan; Lu, Zhaozhi; Song, Yudong; Zhang, Henian

    2003-07-01

    The area of aeolian sand soil in Xinjiang is 3.7189×107 hm2 and occupies 25% of the total land area. Traditionally, it is considered that aeolian sand soil has low yield of crops due to its poor retention power of soil moisture and soil fertility. However, the stems of cotton growing on aeolian sand soil are small and their fictile shape is easy to be controlled. Thus, a culture mode of "increasing stems and bolls, double-layer and double-stem" of cotton is developed by scientific irrigation and fertilizer spread as well as artificial control of fictile shape based on the growth laws of cotton and the properties of aeolian sand soil, and a lint yield of over 3,750 kg/hm2 has been reaped in successive 3 years. Currently, the cotton culture in Xinjiang is rapidly developed, the proportion of cotton-culture areas occupies 40~60%, the cultivating areas of other crops are reduced, the ecosystems are simplified, and the natural enemies in cotton fields are reduced. Alfalfa belts of 8~10 m in width are planted in the zones affected by shelter forests, the occurrence of Therioaphis maculata (Buckton) in alfalfa belts is 10~15 days earlier than that of cotton aphids (Aphis gossypii Glover), and in the alfalfa belts the quantity of herioaphis maculata (Buckton), the natural enemies, is 13.65 times of that in cotton fields when the cotton aphids occur. To resect the alfalfa this moment makes the natural enemies in the alfalfa belts enter the cotton fields and eat cotton aphids, which has good effects for preventing and controlling cotton aphids.

  17. Bt resistance in Australian insect pest species.

    PubMed

    Downes, Sharon; Walsh, Tom; Tay, Wee Tek

    2016-06-01

    Bt cotton was initially deployed in Australia in the mid-1990s to control the polyphagous pest Helicoverpa armigera (Hübner) which was intractably resistant to synthetic chemistries. A conservative strategy was enforced and resistance to first generation single toxin technology was managed. A decade later, shortly after the release of dual toxin cotton, high baseline frequencies of alleles conferring resistance to one of its components prompted a reassessment of the thinking behind the potential risks to this technology. Several reviews detail the characteristics of this resistance and the nuances of deploying first and second generation Bt cotton in Australia. Here we explore recent advances and future possibilities to estimate Bt resistance in Australian pest species and define what we see as the critical data for enabling effective pre-emptive strategies. We also foreshadow the imminent deployment of three toxin (Cry1Ac, Cry2Ab, Vip3A) Bollgard 3 cotton, and examine aspects of resistance to its novel component, Vip3A, that we believe may impact on its stewardship. PMID:27436735

  18. A Black (White) Hole in the Global Spread of GM Cotton.

    PubMed

    Burkitbayeva, Saule; Qaim, Matin; Swinnen, Johan

    2016-04-01

    Bt (Bacillus thuringiensis) cotton has been widely adopted, notably by smallholder farmers in developing countries. However, it has not been used in Central Asia, an important cotton-producing region. We discuss possible reasons and hypothesize that the most likely explanation is limited local demand for Bt owing to low levels of pest infestation. This would imply that global Bt cotton adoption rates may already be close to 100% when considering real demand for insect-resistant varieties. PMID:27017312

  19. Development of transgenic Acala 1517 cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Through backcross breeding, insect resistant Bt genes (W and BGII) and herbicide resistant Roundup Ready genes (RR and RF) have been introduced into Acala 1517 cotton, resulting in the development of one Acala cultivar 1517-99W and a number of elite breeding lines. Acala 1517 germplasm with two Bt g...

  20. Mantis BT Cluster Support

    Energy Science and Technology Software Center (ESTSC)

    2009-06-05

    The software is a modidication to the Mantis BT V1.5 open source application provided by the mantis BT group to support cluster web servers. It also provides various cosmetic modifications used a LLNL.

  1. The present and future role of insect-resistant GM cotton in IPM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transgenic cottons producing Cry toxins from Bacillus thuringiensis (Bt) control lepidopteran pests and were first commercially grown in Australia, Mexico and the USA in 1996. As of 2007, six additional countries (Argentina, Brazil, China, Colombia, India, and South Africa) now grow Bt cotton on a t...

  2. Fall Armyworm (Lepidoptera: Noctuidae) Development, Survivorship, and Damage on Cotton Plants Expressing Insecticidal Plant-Incorporated Protectants.

    PubMed

    Hardke, Jarrod T; Jackson, Ryan E; Leonard, B Rogers; Temple, Joshua H

    2015-06-01

    Cotton, Gossypium hirsutum (L.), plants expressing insecticidal crystal (Cry) proteins of Bacillus thuringiensis (Bt) Berliner are planted on significant acreage across the southern region of the United States. Fall armyworm, Spodoptera frugiperda (J. E. Smith), can be a significant cotton pest in some years, but this species has not been a primary target of Bt cotton technologies. The objective of this study was to quantify fall armyworm larval survivorship and fruiting form injury on transgenic cotton lines expressing Cry1Ac (Bollgard), Cry1Ac+Cry2Ab (Bollgard II), and Cry1Ac+Cry1F (WideStrike) Bt proteins. Larval survivorship and fruiting form damage of fall armyworm on Bollgard, Bollgard II, WideStrike, and non-Bt (control) cotton lines were evaluated in no-choice field studies. Fall armyworm (third instars) were placed on flower buds (squares), white flowers, and bolls, enclosed within a nylon mesh exclusion cage, and evaluated at selected intervals after infestation. Exposure of fall armyworm larvae to Bollgard cotton lines generally resulted in no significant effects on survivorship compared with larvae exposed to the non-Bt cotton line. Survivorship and plant injury by fall armyworm on Bollgard II cotton lines was variable compared with that on non-Bt cotton lines, and significant differences between treatments were inconsistent. Fall armyworm had significantly lower survivorship and caused less plant injury on WideStrike cotton lines than on non-Bt cotton lines across all plant structures. Development and survivorship of fall armyworm larvae on these cotton lines also were evaluated in no-choice laboratory assays by offering the previously described fruiting forms to third instars. Bollgard II and WideStrike cotton lines significantly reduced fall armyworm development and survivorship compared with those larvae offered non-Bt tissue. These results suggest that differences exist among selected Bt cotton technologies in their performance against fall

  3. Bacillus thuringiensis (Bt)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Bacillus thuringiensis (Bt), a natural bacteria found all over the Earth, has a fairly novel way of getting rid of unwanted insects. Bt forms a protein substance (shown on the right) that is not harmful to humans, birds, fish or other vertebrates. When eaten by insect larvae the protein causes a fatal loss of appetite. For over 25 years agricultural chemical companies have relied heavily upon safe Bt pesticides. New space based research promises to give the insecticide a new dimension in effectiveness and applicability. Researchers from the Consortium for Materials Development in Space along with industrial affiliates such as Abott Labs and Pern State University flew Bt on a Space Shuttle mission in the fall of 1996. Researchers expect that the Shuttle's microgravity environment will reveal new information about the protein that will make it more effective against a wider variety of pests.

  4. Cotton (Gossypium hirsutum L.).

    PubMed

    Rathore, Keerti S; Campbell, LeAnne M; Sherwood, Shanna; Nunes, Eugenia

    2015-01-01

    Cotton continues to be a crop of great economic importance in many developing and some developed countries. Cotton plants expressing the Bt gene to deter some of the major pests have been enthusiastically and widely accepted by the farmers in three of the major producing countries, i.e., China, India, and the USA. Considering the constraints related to its production and the wide variety of products derived from the cotton plant, it offers several target traits that can be improved through genetic engineering. Thus, there is a great need to accelerate the application of biotechnological tools for cotton improvement. This requires a simple, yet robust gene delivery/transformant recovery system. Recently, a protocol, involving large-scale, mechanical isolation of embryonic axes from germinating cottonseeds followed by direct transformation of the meristematic cells has been developed by an industrial laboratory. However, complexity of the mechanical device and the patent restrictions are likely to keep this method out of reach of most academic laboratories. In this chapter, we describe the method developed in our laboratory that has undergone further refinements and involves Agrobacterium-mediated transformation of cotton cells, selection of stable transgenic callus lines, and recovery of plants via somatic embryogenesis. PMID:25416245

  5. Bt crops: predicting effects of escaped transgenes on the fitness of wild plants and their herbivores.

    PubMed

    Letourneau, Deborah K; Robinson, Gaden S; Hagen, Joy A

    2003-01-01

    One prominent concern about genetically modified crops is the possibility of environmental impacts from the movement of fitness-enhancing traits to wild plant populations. Decisions to deregulate Bt crops in the USA have relied strongly on arguments that these crops will not interbreed with wild relatives in the permitted growing regions. Limited attention therefore has been directed to analyses of the consequences of gene flow. To provide a transparent evaluation process for risks associated with insecticidal transgene escape, we crafted a series of questions designed to guide this aspect of the risk assessment. We then explored the current knowledge base available for answering such risk-related questions for three Bt crops (cotton, rapeseed, and rice). First, we generated a list of wild relatives of these crops. A definitive list of potential transgene recipients is not yet possible for some crops. Sufficient data are not available for some crops to eliminate certain related plant species from consideration of fertile hybrid formation, thus making lists for these crops subject to speculation. Second, we queried the HOSTS database (UK) to obtain a worldwide listing of lepidopteran species that feed on these crops and their wild relatives, and to determine the host range of the larvae. To our knowledge, this list of 502 lepidopteran species is the first such list published for these crops and wild crop relatives. Third, we used a data set maintained by the Canadian Forest Service to assess Bt toxin susceptibility for these lepidopterans. Only 3% of those species have been tested for susceptibility; and the literature suggests that generalizations about susceptibility among taxa are difficult due to the variability within families. Fourth, we consulted the literature to interpret what is known about the ability of lepidopterans to regulate plant fitness or invasiveness. We could not eliminate the possibility of ecological release due to plant resistance against

  6. Cotton and its interaction with cotton morphology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The morphological plasticity of the cotton plant enables it to be produced in a wide variety of agro-ecological regions (Oosterhuis and Jernstedt 1999). This plasticity essentially translates to the lengthening, shortening, or interruption of its effective flowering period in response to season leng...

  7. Novel Pink Bollworm Resistance to the Bt Toxin:Cryl Ac: Effects on Mating, Oviposition, Larval Development, and Survival.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bt cotton plants are genetically engineered to produce insecticidal toxins from the Bacillus thuringiensis (Bt) bacterium and target key lepidopteran pests. At least four strains of pink bollworm, Pectinophora gossypiella (Saunders), have been selected in the laboratory for resistance to insecticid...

  8. Transgenic Cotton-Fed Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) Affects the Parasitoid Encarsia desantisi Viggiani (Hymenoptera: Aphelinidae) Development.

    PubMed

    Pessoa, R; Rossi, G D; Busoli, A C

    2016-02-01

    Cotton cultivars expressing Cry proteins are widely used to control lepidopteran pests. The effects of transgenic plants containing insecticidal Cry proteins on non-target species must be comprehended for a better and rational use of this technology for pest management. We investigated the influence of the Bt cotton cultivars NuOPAL and FM 975 on biological parameters of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), a non-target pest of Bt cotton cultivars and on its parasitoid Encarsia desantisi Viggiani (Hymenoptera: Aphelinidae). The experiments were conducted in a climatized room, and the non-transgenic near isolines were used for rearing whiteflies as control hosts. The effects of the Bt cotton cultivars on the period of embryonic and larval development and the percentage of adult emergence of B. tabaci were assessed. The period required for embryonic, larval, and pupal development and the percentage of emergence and longevity of E. desantisi females were determined using Bt cotton-fed and non-Bt cotton-fed B. tabaci as hosts. Both Bt cotton cultivars resulted in a decrease of approximately 20% of adult emergence of B. tabaci. Differently, an increase of approximately 10% of adult emergence of E. desantisi was observed for parasitoids that used hosts fed with both Bt cotton cultivars. However, female parasitoid longevity decreased when their hosts were fed on Bt cotton cultivars. Our data suggest that the use of Bt cotton cultivars in association with the biological control agent E. desantisi could be functional for the management of B. tabaci in Bt cotton crops. PMID:26431703

  9. Noctuid Survivorship and Damage in Widestrike, Bollgard, and Bollgard II Cottons in the Lower Rio Grande Valley of Texas.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2004-2006, Bt and non-Bt cottons were evaluated for control of bollworms, tobacco budworms, beet armyworms, and cabbage loopers in a small block trial. Results indicated less cotton damage and greater larval mortality for both dual gene products (Bollgard II® and WideStrike™) compared with Bollg...

  10. Pollen- and Seed-Mediated Transgene Flow in Commercial Cotton Seed Production Fields

    PubMed Central

    Heuberger, Shannon; Ellers-Kirk, Christa; Tabashnik, Bruce E.; Carrière, Yves

    2010-01-01

    Background Characterizing the spatial patterns of gene flow from transgenic crops is challenging, making it difficult to design containment strategies for markets that regulate the adventitious presence of transgenes. Insecticidal Bacillus thuringiensis (Bt) cotton is planted on millions of hectares annually and is a potential source of transgene flow. Methodology/Principal Findings Here we monitored 15 non-Bt cotton (Gossypium hirsutum, L.) seed production fields (some transgenic for herbicide resistance, some not) for gene flow of the Bt cotton cry1Ac transgene. We investigated seed-mediated gene flow, which yields adventitious Bt cotton plants, and pollen-mediated gene flow, which generates outcrossed seeds. A spatially-explicit statistical analysis was used to quantify the effects of nearby Bt and non-Bt cotton fields at various spatial scales, along with the effects of pollinator abundance and adventitious Bt plants in fields, on pollen-mediated gene flow. Adventitious Bt cotton plants, resulting from seed bags and planting error, comprised over 15% of plants sampled from the edges of three seed production fields. In contrast, pollen-mediated gene flow affected less than 1% of the seed sampled from field edges. Variation in outcrossing was better explained by the area of Bt cotton fields within 750 m of the seed production fields than by the area of Bt cotton within larger or smaller spatial scales. Variation in outcrossing was also positively associated with the abundance of honey bees. Conclusions/Significance A comparison of statistical methods showed that our spatially-explicit analysis was more powerful for understanding the effects of surrounding fields than customary models based on distance. Given the low rates of pollen-mediated gene flow observed in this study, we conclude that careful planting and screening of seeds could be more important than field spacing for limiting gene flow. PMID:21152426

  11. E.QUALITY@BT...

    ERIC Educational Resources Information Center

    Macmillan, Roderick H.

    1996-01-01

    Describes a management system developed by BT Laboratories (United Kingdom) that is based on ISO 9001 using the World Wide Web, a hypermedia system, and part of the Internet. Subject matter is presented as an alphabetical list of linked entries, numerous navigational techniques are available, and searching options function within an index file.…

  12. Deerskins and Cotton. Ecological impacts of historical land use in the Central Savannah River Area of the Southeastern US before 1950.

    SciTech Connect

    D.L. White

    2004-01-01

    White, D.L. 2004. Deerskins and Cotton. Ecological impacts of historical land use in the Central Savannah River Area of the Southeastern US before 1950. Final Report. USDA Forest Service, Savannah River, Aiken, SC. 324 pp. Abstract: The history of land use for an area is the history of the way in which humans have manipulated or altered the environment. Most land use activities can be viewed as disturbance to ecosystems. Within a given climatic regime, the interaction of the disturbance regime with vegetation, soil, and landform factors largely determines the distribution and composition of plant and associated animal communities. For these reasons, a greater understanding of the ecological impacts of both human and non-human related disturbance is needed to improve our ability to make natural resource management decisions. This document outlines the land use history of the Savannah River Site and surrounding areas from about 1780 thru 1950, when the site was converted to a government facility for the purposes of national defense.

  13. Resistance monitoring of Heliothis virescens to pyramided cotton varieties with a hydrateable, artificial cotton leaf bioassay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proof of concept was demonstrated for a practical, off the shelf bioassay to monitor for tobacco budworm resistance to pyramided Bt cotton using plant eluants. The bioassay was based on a previously described feeding disruption test using hydrateable artificial diet containing a blue indicator dye, ...

  14. Development and commercial use of Bollgard cotton in the USA--early promises versus today's reality.

    PubMed

    Perlak, F J; Oppenhuizen, M; Gustafson, K; Voth, R; Sivasupramaniam, S; Heering, D; Carey, B; Ihrig, R A; Roberts, J K

    2001-09-01

    Bollgard cotton is the trademark given to a number of varieties of cotton bio-engineered to produce an insecticidal protein from Bacillus thuringiensis (Bt). When produced by the modified cotton plants, this protein controls certain lepidopterous cotton insect pests. Commercially available since 1996, these cotton varieties are purchased under a license agreement in which the growers pay a fee and agree to abide by the terms, which include a 1-year license to use the technology and agreement to participate in an insect resistance management program. Today, Bollgard cotton is grown on more than one-third of all cotton acreage in the USA. This product has reduced cotton production costs and insecticide use by providing an effective alternative to chemical insecticides for the control of tobacco budworm, Heliothis virescens; cotton bollworm, Helicoverpa zea; and pink bollworm, Pectinophora gossypiella. The specificity and safety profile of the Bt protein produced in planta in cotton was maintained. It has retained its selectivity for lepidopterous insects and lacks the characteristics found in potential allergenic proteins. Fiber quality, the agronomic characteristics of the plant and seed composition remain unchanged. New cotton technology is being developed to provide improved insect control and a wider spectrum of activity. These future products could further reduce insecticide use in the production of cotton, while maintaining the high level of safety and reliability that has been demonstrated by five seasons of Bollgard cotton use. PMID:11576434

  15. [Compared biology and behavior of Tetranychus urticae Koch (Acari: Tetranychidae) and Phytoseiulus macropilis (Banks) (Acari: Phytoseiidae) on Bollgard and non-transgenic isoline cotton].

    PubMed

    Esteves Filho, Alberto B; de Oliveira, José V; Torres, Jorge B; Gondim, Manoel G C

    2010-01-01

    The two spotted spider mite, Tetranychus urticae Koch, is a nontarget herbivore of Bt-cotton, but acquires and accumulates higher levels of Cry toxin than that expressed by transgenic plants. This work investigated the development and reproduction of T. urticae and of the predator Phytoseiulus macropilis Banks, during three successive generations looking for potential nontarget effect. In addition, behavioral studies on feeding preference, oviposition, and predation were carried out on Bt and non-Bt cottons. The development and reproduction of T. urticae and P. macropilis was conducted using leaf discs of Bt and non-Bt cottons. Arena containing leaf discs from both cotton types connected by a slide coverslip were also used in the behavioral studies. Averages of the three generations showed that the Bt-cotton does not affect the development, survival of immature stages, and reproductive output of T. urticae and of the predator P. macropilis. Furthermore, the preference for feeding and oviposition of T. urticae and P. macropilis were similar on both cotton types. In addition, P. macropilis exhibited similar predatory behavior on T. urticae fed on both cotton types. Levels of Cry1Ac toxin in T. urticae was 3.97 times greater than that found in the Bt-cotton plants as determined using a ELISA test. Despite of the amount of toxin acquired by the prey (T. urticae), no detectable levels of Cry1Ac were found in the predatory mite P. macropilis. PMID:20676505

  16. Does the growing of Bt maize change populations or ecological functions of non-target animals compared to the growing of conventional non-GM maize? A systematic review protocol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since 1996, genetically modified (GM) crops have been grown on an ever increasing area worldwide. Maize producing a Cry protein from the bacterium Bacillus thuringiensis (Bt) was among the first GM crops released for commercial production and it is the only GM crop currently cultivated in Europe. A ...

  17. Development of a novel-type transgenic cotton plant for control of cotton bollworm.

    PubMed

    Yue, Zhen; Liu, Xiaoguang; Zhou, Zijing; Hou, Guangming; Hua, Jinping; Zhao, Zhangwu

    2016-08-01

    The transgenic Bt cotton plant has been widely planted throughout the world for the control of cotton budworm Helicoverpa armigera (Hubner). However, a shift towards insect tolerance of Bt cotton is now apparent. In this study, the gene encoding neuropeptide F (NPF) was cloned from cotton budworm H. armigera, an important agricultural pest. The npf gene produces two splicing mRNA variants-npf1 and npf2 (with a 120-bp segment inserted into the npf1 sequence). These are predicted to form the mature NPF1 and NPF2 peptides, and they were found to regulate feeding behaviour. Knock down of larval npf with dsNPF in vitro resulted in decreases of food consumption and body weight, and dsNPF also caused a decrease of glycogen and an increase of trehalose. Moreover, we produced transgenic tobacco plants transiently expressing dsNPF and transgenic cotton plants with stably expressed dsNPF. Results showed that H. armigera larvae fed on these transgenic plants or leaves had lower food consumption, body size and body weight compared to controls. These results indicate that NPF is important in the control of feeding of H. armigera and valuable for production of potential transgenic cotton. PMID:26841044

  18. Comparative diversity of arthropods on Bt maize and non-Bt maize in two different cropping systems in South Africa.

    PubMed

    Truter, J; Van Hamburg, H; Van Den Berg, J

    2014-02-01

    The biodiversity of an agroecosystem is not only important for its intrinsic value but also because it influences ecological functions that are vital for crop production in sustainable agricultural systems and the surrounding environment. A concern about genetically modified (GM) crops is the potential negative impact that such crops could have on diversity and abundance of nontarget organisms, and subsequently on ecosystem functions. Therefore, it is essential to assess the potential environmental risk of the release of a GM crop and to study its effect on species assemblages within that ecosystem. Assessment of the impact of Bt maize on the environment is hampered by the lack of basic checklists of species present in maize agroecosystems. The aims of the study were to compile a checklist of arthropods that occur on maize in South Africa and to compare the diversity and abundance of arthropods and functional groups on Bt maize and non-Bt maize. Collections of arthropods were carried out during two growing seasons on Bt maize and non-Bt maize plants at two localities. Three maize fields were sampled per locality during each season. Twenty plants, each of Bt maize and non-Bt maize, were randomly selected from the fields at each site. The arthropods collected during this study were classified to morphospecies level and grouped into the following functional groups: detritivores, herbivores, predators, and parasitoids. Based on feeding strategy, herbivores and predators were further divided into sucking herbivores or predators (piercing-sucking mouthparts) and chewing herbivores or predators (chewing mouthparts). A total of 8,771 arthropod individuals, comprising 288 morphospecies and presenting 20 orders, were collected. Results from this short-term study indicated that abundance and diversity of arthropods in maize and the different functional guilds were not significantly affected by Bt maize, either in terms of diversity or abundance. PMID:24472209

  19. Measuring gene flow in the cultivation of transgenic cotton (Gossypium hirsutum L.).

    PubMed

    Zhang, Bao-Hong; Pan, Xiao-Ping; Guo, Teng-Long; Wang, Qing-Lian; Anderson, Todd A

    2005-09-01

    Transgenic Bt cotton NewCott 33B and transgenic tfd A cotton TFD were chosen to evaluate pollen dispersal frequency and distance of transgenic cotton (Gossypium hirsutum L.) in the Huanghe Valley Cotton-producing Zone, China. The objective was to evaluate the efficacy of biosafety procedures used to reduce pollen movement. A field test plot of transgenic cotton (6 x 6 m) was planted in the middle of a nontransgenic field measuring 210 x 210 m. The results indicated that the pollen of Bt cotton or tfd A cotton could be dispersed into the environment. Out-crossing was highest within the central test plot where progeny from nontransgenic plants, immediately adjacent to transgenic plants, had resistant plant progeny at frequencies up to 10.48%. Dispersal frequency decreased significantly and exponentially as dispersal distance increased. The flow frequency and distance of tfd A and Bt genes were similar, but the pollen-mediated gene flow of tfd A cotton was higher and further to the transgenic block than that of Bt cotton (chi2 = 11.712, 1 degree of freedom, p < 0.001). For the tfd A gene, out-crossing ranged from 10.13% at 1 m to 0.04% at 50 m from the transgenic plants. For the Bt gene, out-crossing ranged from 8.16% at 1 m to 0.08% at 20 m from the transgenic plants. These data were fit to a power curve model: y = 10.1321x-1.4133 with a correlation coefficient of 0.999, and y = 8.0031x-1.483 with a correlation coefficient of 0.998, respectively. In this experiment, the farthest distance of pollen dispersal from transgenic cotton was 50 m. These results indicate that a 60-m buffer zone would serve to limit dispersal of transgenic pollen from small-scale field tests. PMID:16118411

  20. Effects of CuO nanoparticles on insecticidal activity and phytotoxicity in conventional and transgenic cotton.

    PubMed

    Van, Nhan Le; Ma, Chuanxin; Shang, Jianying; Rui, Yukui; Liu, Shutong; Xing, Baoshan

    2016-02-01

    Nanoparticles and transgenic plants are recent scientific developments that require systematic study to understand their potential risks to human health. The effects of CuO nanoparticles (NPs) on Bt-transgenic cotton and conventional cotton are reported here. CuO NPs inhibited the growth, development, nutrient content, and indole-3-acetic acid (IAA) and abscisic acid (ABA) concentrations of transgenic and conventional cotton. Transmission electron microscopy (TEM) images showed CuO NPs aggregated on the epidermis of conventional cotton leaves, whereas it had reached into the cells of transgenic cotton leaves by endocytosis. Most CuO NPs aggregates were found on the root outer epidermis and the rest were located in intercellular spaces of both conventional and Bt-transgenic cottons. CuO NPs enhanced the expression of the exogenous gene encoding of Bt toxin protein in leaves and roots, especially at low CuO NP concentrations, providing an important benefit for Bt cotton insect resistance. PMID:26408972

  1. SOURCE ASSESSMENT: COTTON GINS

    EPA Science Inventory

    This report describes a study of air pollutants from cotton gins. Cotton gins separate cotton fibers from cottonseed and trash. During the 1976 crop year, 2.6 x 10 to the 6th power metric tons of lint cotton were ginned. Particulates composed of cotton dust, cotton lint, fine-lea...

  2. Carbon contributions from roots in cotton based rotations

    NASA Astrophysics Data System (ADS)

    Tan, D. K. Y.; Hulugalle, N. R.

    2012-04-01

    Most research on the decline in soil organic carbon (SOC) stocks in Australian cotton farming systems has focussed on the inputs from above-ground crop residues, with contribution from roots being less studied. This paper aims to outline the contribution of cotton roots and roots of other crops to soil carbon stocks in furrow-irrigated Vertisols in several cotton (Gossypium hirsutum L.)-based rotations. Data was collected from cotton-based rotation systems: cotton monoculture, cotton-vetch (Vicia benghalensis) Roth.), cotton-wheat (Triticum aestivum L.), cotton-wheat-vetch, cotton-corn, corn-corn, cotton-sorghum (Sorghum bicolor L.) and from BollgardTM II (Bt) and non-Bt cotton. Land management systems were permanent beds, with or without standing stubble, and conventional tillage. Root growth in the surface 0.10 m was measured with the core-break method, and that in the 0.10 to 1.0 m depth with a minirhizotron and I-CAP image capture system. These measurements were used to derive root C added to soil through intra-seasonal root death (Clost), C in roots remaining at the end of season (Croot), and total root C added to soil (Ctotal = Croot + Clost). Ctotal in non-Bt cotton (Sicot 80RRF, 0.9 t C/ha/year) was higher than in Bt cotton (Sicot 80RRF, 0.6 t C/ha/year). Overall, Ctotal from cotton roots ranges between 0.5 to 5 t C/ha/year, with Clost contributing 25-70%. Ctotal was greater with vetch than with wheat and was in the order of vetch in cotton-wheat-vetch (5.1 t C/ha/year) > vetch in cotton-vetch (1.9 t C/ha/year) > wheat in cotton-wheat (1.6 t C/ha/year) = wheat in cotton-wheat-vetch (1.7 t C/ha/year). Intra-seasonal root mortality accounted for 12% of total root carbon in vetch and 36% in wheat. Average corn Ctotal with monoculture was 9.3 t/ha and with cotton-corn 5.0 t/ha. Ctotal averaged between both treatments was, thus, of the order of 7.7 t C/ha/year and average Clost 0.04 t/ha/yr. Sorghum roots contributed less carbon with conventional tillage (8.2 t

  3. The Bug Problem in Cotton-Can We Manage Bugs and Boll-Rotting Pathogens Without a Crystal Ball?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As cotton varieties with single-protein (i.e. Bollgard®) protection from caterpillar pests, provided by genetic insertions from Bacillus thuringiensis (Bt) var. kurstaki, are phased out after 2010 and dual-protein (i.e. Bollgard II®, WideStrike®, etc.) transgenic Bt varieties become the only options...

  4. Ecology.

    ERIC Educational Resources Information Center

    National Audubon Society, New York, NY.

    This set of teaching aids consists of nine Audubon Nature Bulletins, providing teachers and students with informational reading on various ecological topics. The bulletins have these titles: Schoolyard Laboratories, Owls and Predators, The Forest Community, Life in Freshwater Marshes, Camouflage in the Animal World, Life in the Desert, The…

  5. On risk and regulation: Bt crops in India.

    PubMed

    Herring, Ronald J

    2014-07-01

    Genetic engineering in agriculture raises contentious politics unknown in other applications of molecular technology. Controversy originated and persists for inter-related reasons; these are not primarily, as frequently assumed, differences over scientific findings, but rather about the relationship of science to 'risk.' First, there are inevitably differences in how to interpret 'risk' in situations in which there are no established findings of specific hazard; 'Knightian uncertainty' defines this condition. Science claims no method of resolution in such cases of uncertainty. Second, science has no claim about risk preferences in a normative sense. In genetic engineering, Knightian uncertainty is pervasive; declaring uncertainty to constitute 'risk' enables a precautionary politics in which no conceivable evidence from science can confirm absence of risk. This is the logic of the precautionary state. The logic of the developmental state is quite different: uncertainty is treated as an inevitable component of change, and therefore a logic of acceptable uncertainty, parallel to acceptable risk of the sort deployed in cost-benefit analysis in other spheres of behavior, dominates policy. India's official position on agricultural biotechnology has been promotional, as expected from a developmental state, but regulation of Bt crops has rested in a section of the state operating more on precautionary than developmental logic. As a result, notwithstanding the developmental success of Bt cotton, Bt brinjal [eggplant, aubergine] encountered a moratorium on deployment despite approval by the regulatory scientific body designated to assess biosafety. PMID:25437239

  6. The presence of Bt-transgenic oilseed rape in wild mustard populations affects plant growth.

    PubMed

    Liu, Yongbo; Stewart, C Neal; Li, Junsheng; Huang, Hai; Zhang, Xitao

    2015-12-01

    The adventitious presence of transgenic plants in wild plant populations is of ecological and regulatory concern, but the consequences of adventitious presence are not well understood. Here, we introduced Bacillus thuringiensis Cry1Ac (Bt)-transgenic oilseed rape (Bt OSR, Brassica napus) with various frequencies into wild mustard (Brassica juncea) populations. We sought to better understand the adventitious presence of this transgenic insecticidal crop in a wild-relative plant population. We assessed the factors of competition, resource availability and diamondback moth (Plutella xylostella) infestation on plant population dynamics. As expected, Bt OSR performed better than wild mustard in mixed populations under herbivore attack in habitats with enough resources, whereas wild mustard had higher fitness when Bt OSR was rarer in habitats with limited resources. Results suggest that the presence of insect-resistant transgenic plants could decrease the growth of wild mustard and Bt OSR plants and their populations, especially under high herbivore pressure. PMID:26338267

  7. Artificial infestations of transgenic cotton with beet armyworm (Lepidoptera: Noctuidae) and evaluation of insect mortality and damage under field conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transgenic cottons containing Bollgard(R), Bollgard II(R), and Widestrike(TM) traits along with nonBt cotton were grown during 2005-2009, to examine efficacy against beet armyworm, Spodoptera exigua (Hubner), and (BAW) in field performance using natural and artificial infestations. Damage and morta...

  8. Efficacy of Cry1F insecticidal protein in maize and cotton for control of fall armyworm (Lepidoptera: Noctuidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Efficacy of maize, Zea mays L., hybrids and cotton, Gossypium hirsutum (L.), varieties expressing Cry1F insecticidal crystal protein of Bacillus thuringiensis (Bt) var. aizawai Berliner (transformation event TC1507 in corn and event DAS-24236-5 in cotton) was evaluated for control of fall armyworm, ...

  9. Fall armyworm (Lepidoptera: Noctuidae) development survivorship and damage on cotton plants expressing insecticidal plant-incorporated protectants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton, Gossypium hirsutum (L.), plants expressing insecticidal crystal (Cry) proteins of Bacillus thuringiensis (Bt) Berliner are planted on significant acreage across the Southern region of the United States. Fall armyworm, Spodoptera frugiperda (J. E. Smith), can be a significant cotton pest in ...

  10. Pentatomid cotton pests in southeastern United States: Shifting pest status and the role of microbes in crop damage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pentatomid stink bug pests, namely Nezara viridula and Euschistus servus, have become the most serious pest groups for cotton production in the southeastern United States in the last few decades. The widespread adoption of transgenic Bt cotton in the region has likely contributed to Pentatomid outb...

  11. Chloroplast-targeted expression of recombinant crystal-protein gene in cotton: an unconventional combat with resistant pests.

    PubMed

    Kiani, Sarfraz; Mohamed, Bahaeldeen Babiker; Shehzad, Kamran; Jamal, Adil; Shahid, Muhammad Naveed; Shahid, Ahmad Ali; Husnain, Tayyab

    2013-07-10

    Plants transformed with single Bt gene are liable to develop insect resistance and this has already been reported in a number of studies carried out around the world where Bt cotton was cultivated on commercial scale. Later, it was envisaged to transform plants with more than one Bt genes in order to combat with resistant larvae. This approach seems valid as various Bt genes possess different binding domains which could delay the likely hazards of insect resistance against a particular Bt toxin. But it is difficult under field conditions to develop homozygous plants expressing all Bt genes equally after many generations without undergoing recombination effects. A number of researches claiming to transform plants from three to seven transgenes in a single plant were reported during the last decade but none has yet applied for patent of homozygous transgenic lines. A better strategy might be to use hybrid-Bt gene(s) modified for improved lectin-binding domains to boost Bt receptor sites in insect midgut. These recombinant-Bt gene(s) would express different lectin domains in a single polypeptide and it is relatively easy to develop homozygous transgenic lines under field conditions. Enhanced chloroplast-localized expression of hybrid-Bt gene would leave no room for insects to develop resistance. We devised and successfully applied this strategy in cotton (Gossypium hirsutum) and data up to T3 generation showed that our transgenic cotton plants were displaying enhanced chloroplast-targeted Cry1Ac-RB expression. Laboratory and field bioassays gave promising results against American bollworm (Heliothis armigera), pink bollworm (Pictinophora scutigera) and fall armyworm (Spodoptera frugiperda) that otherwise, were reported to have evolved resistance against Cry1Ac toxin. Elevated levels of hybrid-Bt toxin were confirmed by ELISA of chloroplast-enriched protein samples extracted from leaves of transgenic cotton lines. While, localization of recombinant Cry1Ac-RB protein in

  12. Frequency of Bt resistance alleles in H. armigera during 2006-2008 in Northern China.

    PubMed

    Gao, Yulin; Wu, Kongming; Gould, Fred

    2009-08-01

    Helicoverpa armigera is an important lepidopteran pest of cotton in China. From 2002, the frequency of Bt resistance alleles and quantitative shifts in larval Cry1Ac tolerance of field H. armigera population were monitored using bioassays of F(1) and F(2) offspring of isofemale lines from Xiajin County of Shandong Province (an intensive Bt cotton planting area) and Anci County of Hebei Province (a multiple-crop system including corn, soybean, peanut, and Bt cotton) in northern China. During 2006-2008, a total of 2,306 isofemale lines from the Xiajin population and a total of 1,270 isofemale lines from the Anci population were successfully screened on Cry1Ac diets. For each year, it was estimated that the major resistance gene frequency in Xiajin population in 2006, 2007, and 2008 was 0, 0.00022, and 0.00033, respectively. No major alleles conferring resistance to Cry1Ac were found in the Anci population; the frequency of resistance alleles for Cry1Ac was 0. Based on the relative average development rates (RADRs) of H. armigera larvae in F(1) tests, no substantial increase in Cry1Ac tolerance was found in either location over the 3-yr period. There were also significantly positive correlations between RADR of lines in the F(1) generation and the RADR of their F(2) offspring, indicating genetic variation in response to toxin. The low frequency of resistance alleles found in this study and in our previous results from 2002 to 2005 suggest the frequency of resistance alleles has remained low and that natural refugia resistance management strategy maybe effective for delaying resistance evolution in H. armigera to Bt cotton in northern China. PMID:19689916

  13. Impacts of transgenic poplar-cotton agro-ecosystems upon target pests and non-target insects under field conditions.

    PubMed

    Zhang, D J; Liu, J X; Lu, Z Y; Li, C L; Comada, E; Yang, M S

    2015-01-01

    Poplar-cotton agro-ecosystems are the main agricultural planting modes of cotton fields in China. With increasing acres devoted to transgenic insect-resistant poplar and transgenic insect-resistant cotton, studies examining the effects of transgenic plants on target and non-target insects become increasingly important. We systematically surveyed populations of both target pests and non-target insects for 4 different combinations of poplar-cotton eco-systems over 3 years. Transgenic Bt cotton strongly resisted the target insects Fall webworm moth [Hyphantria cunea (Drury)], Sylepta derogata Fabrieius, and American bollworm (Heliothis armigera), but no clear impact on non-target insect cotton aphids (Aphis gossypii). Importantly, intercrops containing transgenic Pb29 poplar significantly increased the inhibitory effects of Bt cotton on Fall webworm moth in ecosystem IV. Highly resistant Pb29 poplar reduced populations of the target pests Grnsonoma minutara Hubner and non-target insect poplar leaf aphid (Chaitophorus po-pulialbae), while Fall webworm moth populations were unaffected. We determined the effects of Bt toxin from transgenic poplar and cotton on target and non-target pests in different ecosystems of cotton-poplar intercrops and identified the synergistic effects of such combinations toward both target and non-target insects. PMID:26345739

  14. Cotton Harvesting

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton harvesting is performed in the US using either a spindle picker or brush-roll stripper. This presentation discusses the environmental, economic, geographic, and cultivar specific reasons behind a grower's choice to use either machine. The development of each machine system was discussed. A...

  15. Potential shortfall of pyramided transgenic cotton for insect resistance management

    PubMed Central

    Brévault, Thierry; Heuberger, Shannon; Zhang, Min; Ellers-Kirk, Christa; Ni, Xinzhi; Masson, Luke; Li, Xianchiun; Tabashnik, Bruce E.; Carrière, Yves

    2013-01-01

    To delay evolution of pest resistance to transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt), the “pyramid” strategy uses plants that produce two or more toxins that kill the same pest. In the United States, this strategy has been adopted widely, with two-toxin Bt cotton replacing one-toxin Bt cotton. Although two-toxin plants are likely to be more durable than one-toxin plants, the extent of this advantage depends on several conditions. One key assumption favoring success of two-toxin plants is that they kill insects selected for resistance to one toxin, which is called “redundant killing.” Here we tested this assumption for a major pest, Helicoverpa zea, on transgenic cotton producing Bt toxins Cry1Ac and Cry2Ab. Selection with Cry1Ac increased survival on two-toxin cotton, which contradicts the assumption. The concentration of Cry1Ac and Cry2Ab declined during the growing season, which would tend to exacerbate this problem. Furthermore, analysis of results from 21 selection experiments with eight species of lepidopteran pests indicates that some cross-resistance typically occurs between Cry1A and Cry2A toxins. Incorporation of empirical data into simulation models shows that the observed deviations from ideal conditions could greatly reduce the benefits of the pyramid strategy for pests like H. zea, which have inherently low susceptibility to Bt toxins and have been exposed extensively to one of the toxins in the pyramid before two-toxin plants are adopted. For such pests, the pyramid strategy could be improved by incorporating empirical data on deviations from ideal assumptions about redundant killing and cross-resistance. PMID:23530245

  16. Potential shortfall of pyramided transgenic cotton for insect resistance management.

    PubMed

    Brévault, Thierry; Heuberger, Shannon; Zhang, Min; Ellers-Kirk, Christa; Ni, Xinzhi; Masson, Luke; Li, Xianchiun; Tabashnik, Bruce E; Carrière, Yves

    2013-04-01

    To delay evolution of pest resistance to transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt), the "pyramid" strategy uses plants that produce two or more toxins that kill the same pest. In the United States, this strategy has been adopted widely, with two-toxin Bt cotton replacing one-toxin Bt cotton. Although two-toxin plants are likely to be more durable than one-toxin plants, the extent of this advantage depends on several conditions. One key assumption favoring success of two-toxin plants is that they kill insects selected for resistance to one toxin, which is called "redundant killing." Here we tested this assumption for a major pest, Helicoverpa zea, on transgenic cotton producing Bt toxins Cry1Ac and Cry2Ab. Selection with Cry1Ac increased survival on two-toxin cotton, which contradicts the assumption. The concentration of Cry1Ac and Cry2Ab declined during the growing season, which would tend to exacerbate this problem. Furthermore, analysis of results from 21 selection experiments with eight species of lepidopteran pests indicates that some cross-resistance typically occurs between Cry1A and Cry2A toxins. Incorporation of empirical data into simulation models shows that the observed deviations from ideal conditions could greatly reduce the benefits of the pyramid strategy for pests like H. zea, which have inherently low susceptibility to Bt toxins and have been exposed extensively to one of the toxins in the pyramid before two-toxin plants are adopted. For such pests, the pyramid strategy could be improved by incorporating empirical data on deviations from ideal assumptions about redundant killing and cross-resistance. PMID:23530245

  17. Cotton Production Practices Change Soil Properties

    NASA Astrophysics Data System (ADS)

    Blaise, D.; Singh, J. V.

    2012-04-01

    Historically, indigenous Asiatic cottons (Gossypium arboreum) were cultivated with minimal inputs in India. The introduction of the Upland cottons (G. hirsutum) and later the hybrid (H-4) triggered a whole set of intensified agronomic management with reliance on high doses of fertilisers and pesticide usage. In 2002, the transgenic Bt cotton hybrids were introduced and released for commercial cultivation. Presently, more than 95% of the nearly 12.2 million hectares of cotton area is under the Bt transgenic hybrids. These hybrids are not only high yielding but have reduced the dependence on pesticide because of an effective control of the lepidopteran pests. Thus, a change in the management practices is evident over the years. In this paper, we discuss the impact of two major agronomic management practices namely, nutrient management and tillage besides organic cotton cultivation in the rainfed cotton growing regions of central India characterized by sub-humid to semi-arid climate and dominated by Vertisols. Long-term studies at Nagpur, Maharashtra indicated the importance of integrated nutrient management (INM) wherein a part of the nutrient needs through fertiliser was substituted with organic manures such as farmyard manure (FYM). With the application of mineral fertilisers alone, soils became deficient in micronutrients. This was not observed with the FYM amended plots. Further, the manure amended plots had a better soil physical properties and the water holding capacity of the soil improved due to improvements in soil organic matter (SOM). Similarly, in a separate experiment, an improvement in SOM was observed in the organically managed fields because of continuous addition of organic residues. Further, it resulted in greater biological activity compared to the conventionally managed fields. Conservation tillage systems such as reduced tillage (RT) are a means to improve soil health and crop productivity. Long-term studies on tillage practices such as

  18. The impact of secondary pests on Bacillus thuringiensis (Bt) crops.

    PubMed

    Catarino, Rui; Ceddia, Graziano; Areal, Francisco J; Park, Julian

    2015-06-01

    The intensification of agriculture and the development of synthetic insecticides enabled worldwide grain production to more than double in the last third of the 20th century. However, the heavy dependence and, in some cases, overuse of insecticides has been responsible for negative environmental and ecological impacts across the globe, such as a reduction in biodiversity, insect resistance to insecticides, negative effects on nontarget species (e.g. natural enemies) and the development of secondary pests. The use of recombinant DNA technology to develop genetically engineered insect-resistant crops could mitigate many of the negative side effects of insecticides. One such genetic alteration enables crops to express toxic crystalline (Cry) proteins from the soil bacteria Bacillus thuringiensis (Bt). Despite the widespread adoption of Bt crops, there are still a range of unanswered questions concerning longer term agro-ecosystem interactions. For instance, insect species that are not susceptible to the expressed toxin can develop into secondary pests and cause significant damage to the crop. Here, we review the main causes surrounding secondary pest dynamics in Bt crops and the impact of such outbreaks. Regardless of the causes, if nonsusceptible secondary pest populations exceed economic thresholds, insecticide spraying could become the immediate solution at farmers' disposal, and the sustainable use of this genetic modification technology may be in jeopardy. Based on the literature, recommendations for future research are outlined that will help to improve the knowledge of the possible long-term ecological trophic interactions of employing this technology. PMID:25832330

  19. Cry2Ab tolerance response of Helicoverpa armigera (Lepidoptera: Noctuidae) populations from CrylAc cotton planting region.

    PubMed

    Gao, Yulin; Wu, Kongming; Gould, Fred; Shen, Zhicheng

    2009-06-01

    Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is an important lepidopteran pest of cotton, Gossypium hirsutum L., in Asia. Transgenic cotton expressing the cry1Ac gene from Bacillus thuringiensis (Bt) has been widely planted for control of this pest. For managing the potential risk from resistance evolution in this pest, a new transgenic Bt cotton containing cry1Ac and cry2Ab genes (gene pyramided strategy) was designed as a successor of cry1Ac cotton. This article reports on levels of Cry2Ab tolerance in H. armigera populations from CrylAc cotton planting region in China based on bioassays of F1 and F2 offspring of isofemale lines. In total, 572 isofemale families of H. armigera from Xiajin County of Shandong Province (an intensive Bt cotton-planting area) and 124 families from Anci County of Hebei Province [a multiple-crop system, including corn (Zea mays L.), soybean (Gycine max (L.) Merr., peanut (Arachis spp.), and Bt cotton] were screened with both Cry1Ac- and Cry2Ab-containing diets in 2008. The bioassays results indicated that relative average development rates (RADR) of F1 full-sib families from field-collected female moths on Cry1Ac- and Cry2Ab-containing diet were positively correlated. The same correlation was found in the F2 generation, indicating cross-tolerance between Cry1Ac and Cry2Ab in field populations of H. armigera in Yellow River cotton-farming region of China. This cross-tolerance must be considered in evaluating the utility of pyramiding Bt genes in cotton for delaying evolution of resistance. PMID:19610441

  20. Yield and Economic Performance of Organic and Conventional Cotton-Based Farming Systems – Results from a Field Trial in India

    PubMed Central

    Forster, Dionys; Andres, Christian; Verma, Rajeev; Zundel, Christine; Messmer, Monika M.; Mäder, Paul

    2013-01-01

    The debate on the relative benefits of conventional and organic farming systems has in recent time gained significant interest. So far, global agricultural development has focused on increased productivity rather than on a holistic natural resource management for food security. Thus, developing more sustainable farming practices on a large scale is of utmost importance. However, information concerning the performance of farming systems under organic and conventional management in tropical and subtropical regions is scarce. This study presents agronomic and economic data from the conversion phase (2007–2010) of a farming systems comparison trial on a Vertisol soil in Madhya Pradesh, central India. A cotton-soybean-wheat crop rotation under biodynamic, organic and conventional (with and without Bt cotton) management was investigated. We observed a significant yield gap between organic and conventional farming systems in the 1st crop cycle (cycle 1: 2007–2008) for cotton (−29%) and wheat (−27%), whereas in the 2nd crop cycle (cycle 2: 2009–2010) cotton and wheat yields were similar in all farming systems due to lower yields in the conventional systems. In contrast, organic soybean (a nitrogen fixing leguminous plant) yields were marginally lower than conventional yields (−1% in cycle 1, −11% in cycle 2). Averaged across all crops, conventional farming systems achieved significantly higher gross margins in cycle 1 (+29%), whereas in cycle 2 gross margins in organic farming systems were significantly higher (+25%) due to lower variable production costs but similar yields. Soybean gross margin was significantly higher in the organic system (+11%) across the four harvest years compared to the conventional systems. Our results suggest that organic soybean production is a viable option for smallholder farmers under the prevailing semi-arid conditions in India. Future research needs to elucidate the long-term productivity and profitability, particularly of

  1. Yield and economic performance of organic and conventional cotton-based farming systems--results from a field trial in India.

    PubMed

    Forster, Dionys; Andres, Christian; Verma, Rajeev; Zundel, Christine; Messmer, Monika M; Mäder, Paul

    2013-01-01

    The debate on the relative benefits of conventional and organic farming systems has in recent time gained significant interest. So far, global agricultural development has focused on increased productivity rather than on a holistic natural resource management for food security. Thus, developing more sustainable farming practices on a large scale is of utmost importance. However, information concerning the performance of farming systems under organic and conventional management in tropical and subtropical regions is scarce. This study presents agronomic and economic data from the conversion phase (2007-2010) of a farming systems comparison trial on a Vertisol soil in Madhya Pradesh, central India. A cotton-soybean-wheat crop rotation under biodynamic, organic and conventional (with and without Bt cotton) management was investigated. We observed a significant yield gap between organic and conventional farming systems in the 1(st) crop cycle (cycle 1: 2007-2008) for cotton (-29%) and wheat (-27%), whereas in the 2(nd) crop cycle (cycle 2: 2009-2010) cotton and wheat yields were similar in all farming systems due to lower yields in the conventional systems. In contrast, organic soybean (a nitrogen fixing leguminous plant) yields were marginally lower than conventional yields (-1% in cycle 1, -11% in cycle 2). Averaged across all crops, conventional farming systems achieved significantly higher gross margins in cycle 1 (+29%), whereas in cycle 2 gross margins in organic farming systems were significantly higher (+25%) due to lower variable production costs but similar yields. Soybean gross margin was significantly higher in the organic system (+11%) across the four harvest years compared to the conventional systems. Our results suggest that organic soybean production is a viable option for smallholder farmers under the prevailing semi-arid conditions in India. Future research needs to elucidate the long-term productivity and profitability, particularly of cotton and

  2. Mode of inheritance for biochemical traits in genetically engineered cotton under water stress.

    PubMed

    Abid, Muhammad Ali; Malik, Waqas; Yasmeen, Azra; Qayyum, Abdul; Zhang, Rui; Liang, Chengzhen; Guo, Sandui; Ashraf, Javaria

    2016-01-01

    Drought is an abiotic environmental stress that can significantly reduce crop productivity. We examined the mode of inheritance for different biochemical traits including total soluble proteins, chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, total phenolic contents and enzymatic antioxidants (superoxide dismutase, peroxidase and catalase), and their relationship with Bacillus thuringiensis (Bt) toxin under control and drought conditions. Eight genetically diverse cotton genotypes were selfed for two generations to ensure homozygosity. Fifteen F1 hybrids were developed by crossing five non-Bt female lines with three Bt male testers. The F1 hybrids and eight parents were finally evaluated under control (100 % field capacity (FC)) and drought (50 % FC) conditions in 2013. The biochemical traits appeared to be controlled by non-additive gene action with low narrow sense heritability estimates. The estimates of general combining ability and specific combining ability for all biochemical traits were significant under control and drought conditions. The genotype-by-trait biplot analysis showed the better performance of Bt cotton hybrids when compared with their parental genotypes for various biochemical traits under control and drought conditions. The biplot and path coefficient analyses revealed the prevalence of different relationships between Cry1Ac toxin and biochemical traits in the control and drought conditions. In conclusion, biochemical traits could serve as potential biochemical markers for breeding Bt cotton genotypes without compromising the optimal level of Bt toxin. PMID:26839284

  3. Mode of inheritance for biochemical traits in genetically engineered cotton under water stress

    PubMed Central

    Abid, Muhammad Ali; Malik, Waqas; Yasmeen, Azra; Qayyum, Abdul; Zhang, Rui; Liang, Chengzhen; Guo, Sandui; Ashraf, Javaria

    2016-01-01

    Drought is an abiotic environmental stress that can significantly reduce crop productivity. We examined the mode of inheritance for different biochemical traits including total soluble proteins, chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, total phenolic contents and enzymatic antioxidants (superoxide dismutase, peroxidase and catalase), and their relationship with Bacillus thuringiensis (Bt) toxin under control and drought conditions. Eight genetically diverse cotton genotypes were selfed for two generations to ensure homozygosity. Fifteen F1 hybrids were developed by crossing five non-Bt female lines with three Bt male testers. The F1 hybrids and eight parents were finally evaluated under control (100 % field capacity (FC)) and drought (50 % FC) conditions in 2013. The biochemical traits appeared to be controlled by non-additive gene action with low narrow sense heritability estimates. The estimates of general combining ability and specific combining ability for all biochemical traits were significant under control and drought conditions. The genotype-by-trait biplot analysis showed the better performance of Bt cotton hybrids when compared with their parental genotypes for various biochemical traits under control and drought conditions. The biplot and path coefficient analyses revealed the prevalence of different relationships between Cry1Ac toxin and biochemical traits in the control and drought conditions. In conclusion, biochemical traits could serve as potential biochemical markers for breeding Bt cotton genotypes without compromising the optimal level of Bt toxin. PMID:26839284

  4. [Potential effects of Bt transgenic rice on soil micro-ecosystem].

    PubMed

    Wang, Zhonghua

    2005-12-01

    With the increasing commercial use of genetically modified crops (GMCs), it is quite important to assess their potential ecological risk. The likelihood of genes dispersal from GMCs to related wild species, the tolerance of insects to insect-resistant GMCs, and the potential impact of GMCs on biodiversity have been extensively investigated. This article reviewed the potential ecological risk assessment of transgenic Bt rice-expressed products, including the persistence characteristics of Bt insecticidal crystal proteins in soil, and their effects on soil culturable microbial flora and soil enzyme activities, which could provide useful information for related researches. PMID:16515209

  5. CottonDB: Cotton Genome Database

    Technology Transfer Automated Retrieval System (TEKTRAN)

    CottonDB (www.cottondb.org) is the first and most comprehensive source of cotton genome information. CottonDB is maintained at the Southern Plains Agricultural Research Center in College Station, TX. The project includes a website and database creating a repository of information for over 355,000 ...

  6. The food and environmental safety of Bt crops

    PubMed Central

    Koch, Michael S.; Ward, Jason M.; Levine, Steven L.; Baum, James A.; Vicini, John L.; Hammond, Bruce G.

    2015-01-01

    Bacillus thuringiensis (Bt) microbial pesticides have a 50-year history of safety in agriculture. Cry proteins are among the active insecticidal ingredients in these pesticides, and genes coding for Cry proteins have been introduced into agricultural crops using modern biotechnology. The Cry gene sequences are often modified to enable effective expression in planta and several Cry proteins have been modified to increase biological activity against the target pest(s). Additionally, the domains of different but structurally conserved Cry proteins can be combined to produce chimeric proteins with enhanced insecticidal properties. Environmental studies are performed and include invertebrates, mammals, and avian species. Mammalian studies used to support the food and feed safety assessment are also used to support the wild mammal assessment. In addition to the NTO assessment, the environmental assessment includes a comparative assessment between the Bt crop and the appropriate conventional control that is genetically similar but lacks the introduced trait to address unintended effects. Specific phenotypic, agronomic, and ecological characteristics are measured in the Bt crop and the conventional control to evaluate whether the introduction of the insect resistance has resulted in any changes that might cause ecological harm in terms of altered weed characteristics, susceptibility to pests, or adverse environmental impact. Additionally, environmental interaction data are collected in field experiments for Bt crop to evaluate potential adverse effects. Further to the agronomic and phenotypic evaluation, potential movement of transgenes from a genetically modified crop plants into wild relatives is assessed for a new pest resistance gene in a new crop. This review summarizes the evidence for safety of crops containing Cry proteins for humans, livestock, and other non-target organisms. PMID:25972882

  7. The food and environmental safety of Bt crops.

    PubMed

    Koch, Michael S; Ward, Jason M; Levine, Steven L; Baum, James A; Vicini, John L; Hammond, Bruce G

    2015-01-01

    Bacillus thuringiensis (Bt) microbial pesticides have a 50-year history of safety in agriculture. Cry proteins are among the active insecticidal ingredients in these pesticides, and genes coding for Cry proteins have been introduced into agricultural crops using modern biotechnology. The Cry gene sequences are often modified to enable effective expression in planta and several Cry proteins have been modified to increase biological activity against the target pest(s). Additionally, the domains of different but structurally conserved Cry proteins can be combined to produce chimeric proteins with enhanced insecticidal properties. Environmental studies are performed and include invertebrates, mammals, and avian species. Mammalian studies used to support the food and feed safety assessment are also used to support the wild mammal assessment. In addition to the NTO assessment, the environmental assessment includes a comparative assessment between the Bt crop and the appropriate conventional control that is genetically similar but lacks the introduced trait to address unintended effects. Specific phenotypic, agronomic, and ecological characteristics are measured in the Bt crop and the conventional control to evaluate whether the introduction of the insect resistance has resulted in any changes that might cause ecological harm in terms of altered weed characteristics, susceptibility to pests, or adverse environmental impact. Additionally, environmental interaction data are collected in field experiments for Bt crop to evaluate potential adverse effects. Further to the agronomic and phenotypic evaluation, potential movement of transgenes from a genetically modified crop plants into wild relatives is assessed for a new pest resistance gene in a new crop. This review summarizes the evidence for safety of crops containing Cry proteins for humans, livestock, and other non-target organisms. PMID:25972882

  8. A transgenic approach for controlling Lygus in cotton.

    PubMed

    Gowda, Anilkumar; Rydel, Timothy J; Wollacott, Andrew M; Brown, Robert S; Akbar, Waseem; Clark, Thomas L; Flasinski, Stanislaw; Nageotte, Jeffrey R; Read, Andrew C; Shi, Xiaohong; Werner, Brent J; Pleau, Michael J; Baum, James A

    2016-01-01

    Lygus species of plant-feeding insects have emerged as economically important pests of cotton in the United States. These species are not controlled by commercial Bacillus thuringiensis (Bt) cotton varieties resulting in economic losses and increased application of insecticide. Previously, a Bt crystal protein (Cry51Aa2) was reported with insecticidal activity against Lygus spp. However, transgenic cotton plants expressing this protein did not exhibit effective protection from Lygus feeding damage. Here we employ various optimization strategies, informed in part by protein crystallography and modelling, to identify limited amino-acid substitutions in Cry51Aa2 that increase insecticidal activity towards Lygus spp. by >200-fold. Transgenic cotton expressing the variant protein, Cry51Aa2.834_16, reduce populations of Lygus spp. up to 30-fold in whole-plant caged field trials. One transgenic event, designated MON88702, has been selected for further development of cotton varieties that could potentially reduce or eliminate insecticide application for control of Lygus and the associated environmental impacts. PMID:27426014

  9. A transgenic approach for controlling Lygus in cotton

    PubMed Central

    Gowda, Anilkumar; Rydel, Timothy J.; Wollacott, Andrew M.; Brown, Robert S.; Akbar, Waseem; Clark, Thomas L.; Flasinski, Stanislaw; Nageotte, Jeffrey R.; Read, Andrew C.; Shi, Xiaohong; Werner, Brent J.; Pleau, Michael J.; Baum, James A.

    2016-01-01

    Lygus species of plant-feeding insects have emerged as economically important pests of cotton in the United States. These species are not controlled by commercial Bacillus thuringiensis (Bt) cotton varieties resulting in economic losses and increased application of insecticide. Previously, a Bt crystal protein (Cry51Aa2) was reported with insecticidal activity against Lygus spp. However, transgenic cotton plants expressing this protein did not exhibit effective protection from Lygus feeding damage. Here we employ various optimization strategies, informed in part by protein crystallography and modelling, to identify limited amino-acid substitutions in Cry51Aa2 that increase insecticidal activity towards Lygus spp. by >200-fold. Transgenic cotton expressing the variant protein, Cry51Aa2.834_16, reduce populations of Lygus spp. up to 30-fold in whole-plant caged field trials. One transgenic event, designated MON88702, has been selected for further development of cotton varieties that could potentially reduce or eliminate insecticide application for control of Lygus and the associated environmental impacts. PMID:27426014

  10. Dictionary of cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton is an essential commodity for textiles and has long been an important item of trade in the world’s economy. Cotton is currently grown in over 100 countries by an estimated 100 producers. The basic unit of the cotton trade is the cotton bale which consists of approximately 500 pounds of raw c...

  11. Partnership and Workplace Learning at BT

    ERIC Educational Resources Information Center

    Education & Training, 2002

    2002-01-01

    Explores BT's partnership with the Communication Workers' Union and London University's Queen Mary and Westfield College and examines its significance for the development of a degree level programme of workplace learning. Describes the programme's philosophy, aims, funding and effectiveness. Incorporates interviews with BT managers, trade union…

  12. Does Bt Corn Really Produce Tougher Residues

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bt corn hybrids produce insecticidal proteins that are derived from a bacterium, Bacillus thuringiensis. There have been concerns that Bt corn hybrids produce residues that are relatively resistant to decomposition. We conducted four experiments that examined the decomposition of corn residues und...

  13. Bt Crop Effects on Functional Guilds of Non-target Arthropods: A Meta-Analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Uncertainty continues to persist over the potential environmental effects of crops genetically engineered to produce the insecticidal Cry toxins of Bacillus thuringiensis (Bt). Little work has examined broader impacts on ecological function of non-target species within agroecosystems. Here we use me...

  14. Nutrition as a neglected factor in insect herbivore susceptibility to Bt toxins.

    PubMed

    Deans, C A; Sword, G A; Behmer, S T

    2016-06-01

    The widespread global adoption of Bt crops elevates concerns about the evolution of Bt resistance in insect pest species. Current insecticide resistance management (IRM) strategies focus solely on genetic variation as a causal factor in the evolution of resistance, but ignore the role that environmental factors, such as nutrition, may play. In this opinion paper, we discuss the benefits that insect herbivores gain from consuming foods with protein-carbohydrate content that matches their self-selected protein-carbohydrate intake, and show that even within monocultures there is amply opportunity for insect herbivores to regulate their macronutrient intake. Next we review new data that show that dietary protein and carbohydrates can: firstly, have predictably strong effects on the survival and performance of caterpillars challenged with Bt toxins, and secondly, mediate plasticity in susceptibility to Cry1Ac, which can account for large differences in LC50 values. Nutrition-Bt interactions such as these have important implications for IRM, particularly given that diet-incorporated Bt bioassays commonly use artificial diets that vary substantially from their self-selected optimal diets, which likely results in underestimates of resistance in the field. Failing to bioassay larvae on ecologically-relevant diets can seriously confound the results of Bt resistance monitoring bioassays and undermine our ability to detect resistance in the field. PMID:27436738

  15. The Present and Future Role of Insect-Resistant GM Crops in Cotton IPM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transgenic cottons producing Cry toxins from Bacillus thuringiensis (Bt) provide for control of lepidopteran pests and were first commercially grown in Australia, Mexico and the USA in 1996. As of 2006, a total of six additional countries (Argentina, Brazil, China, Colombia, India, and South Africa...

  16. Smart textiles: Tough cotton

    NASA Astrophysics Data System (ADS)

    Avila, Alba G.; Hinestroza, Juan P.

    2008-08-01

    Cotton is an important raw material for producing soft textiles and clothing. Recent discoveries in functionalizing cotton fibres with nanotubes may offer a new line of tough, wearable, smart and interactive garments.

  17. Interactions of Bacillus thuringiensis Cry1Ac toxin in genetically engineered cotton with predatory heteropterans.

    PubMed

    Torres, Jorge B; Ruberson, John R

    2008-06-01

    A number of cotton varieties have been genetically transformed with genes from Bacillus thuringiensis (Bt) to continuously produce Bt endotoxins, offering whole plant and season-long protection against many lepidopteran larvae. Constant whole-plant toxin expression creates a significant opportunity for non-target herbivores to acquire and bio-accumulate the toxin for higher trophic levels. In the present study we investigated movement of Cry1Ac toxin from the transgenic cotton plant through specific predator-prey pairings, using omnivorous predators with common cotton pests as prey: (1) the beet armyworm, Spodoptera exigua (Lepidoptera: Noctuidae), with the predator Podisus maculiventris (Heteroptera: Pentatomidae); (2) the two-spotted spider mite, Tetranychus urticae (Acarina: Tetranychidae), with the predatory big-eyed bug Geocoris punctipes (Heteroptera: Geocoridae) and (3) with the predatory damsel bug Nabis roseipennis (Heteropera: Nabidae); and (4) the thrips Frankliniella occidentalis (Thysanoptera: Thripidae) with the predatory pirate bug Orius insidiosus (Heteroptera: Anthocoridae). We quantified Cry1Ac toxin in the cotton plants, and in the pests and predators, and the effects of continuous feeding on S. exigua larvae fed either Bt or non-Bt cotton on life history traits of P. maculiventris. All three herbivores were able to convey Cry1Ac toxin to their respective predators. Among the herbivores, T. urticae exhibited 16.8 times more toxin in their bodies than that expressed in Bt-cotton plant, followed by S. exigua (1.05 times), and F. occidentalis immatures and adults (0.63 and 0.73 times, respectively). Of the toxin in the respective herbivorous prey, 4, 40, 17 and 14% of that amount was measured in the predators G. punctipes, P. maculiventris, O. insidiosus, and N. roseipennis, respectively. The predator P. maculiventris exhibited similar life history characteristics (developmental time, survival, longevity, and fecundity) regardless of the prey's food

  18. Behavior of bollworm (Lepidoptera: Noctuidae) larvae on genetically engineered cotton.

    PubMed

    Gore, J; Leonard, B R; Church, G E; Cook, D R

    2002-08-01

    Reports of bollworm, Helicoverpa zea (Boddie), larvae feeding in white flowers of Bollgard cotton have been relatively common since the commercialization of this technology in 1996. Field studies were conducted in Louisiana to determine if differences in bollworm larval behavior occuron non-Bollgard (cultivar 'Deltapine 5415') and Bacillus thuringiensis (Bt), Bollgard ('NuCOTN 33B') cottons. Larvae were placed on the terminal foliage of either single cotton plants or on all plants within 1-m row micro-plots. On preflowering cotton plants, significantly more bollworms moved from the site of infestation (terminal) on Bollgard plants compared with that on non-Bollgard plants. On individual flowering plants, the number of nodes larvae moved from the terminal and the number of infested bolls was greater on Bollgard cotton plants. Similar differences between Bollgard and non-Bollgard plants in the percentage of infested terminals and squares were observed at 48-h after infestation when 1-m rows were infested. These data will be used to refine scouting protocols for bollworm larvae on Bollgard cotton. PMID:12216818

  19. Nematode Management in Cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The five most important cotton-producing countries are China, United States, India, Pakistan, and Brazil. There are many other important cotton producing regions in Asia, Australia, Africa, and the Americas. Cotton is grown entirely in tropical, subtropical, and warm-temperature climates, and the ...

  20. Dictionary of Cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Dictionary of Cotton has over 2,000 terms and definitions that were compiled by 33 researchers. It reflects the ongoing commitment of the International Cotton Advisory Committee, through its Technical Information Section, to the spread of knowledge about cotton to all those who have an interest ...

  1. CottonDB enhancement

    Technology Transfer Automated Retrieval System (TEKTRAN)

    CottonDB (www.cottondb.org) was initiated in 1995. It is a database that contains genomic, genetic, and taxonomic information for cotton (Gossypium spp.). It serves both as an archival database and as a dynamic database, which incorporates new data and user resources. CottonDB is maintained at th...

  2. Bt Crops Producing Cry1Ac, Cry2Ab and Cry1F Do Not Harm the Green Lacewing, Chrysoperla rufilabris

    PubMed Central

    Tian, Jun-Ce; Wang, Xiang-Ping; Long, Li-Ping; Romeis, Jörg; Naranjo, Steven E.; Hellmich, Richard L.; Wang, Ping; Earle, Elizabeth D.; Shelton, Anthony M.

    2013-01-01

    The biological control function provided by natural enemies is regarded as a protection goal that should not be harmed by the application of any new pest management tool. Plants producing Cry proteins from the bacterium, Bacillus thuringiensis (Bt), have become a major tactic for controlling pest Lepidoptera on cotton and maize and risk assessment studies are needed to ensure they do not harm important natural enemies. However, using Cry protein susceptible hosts as prey often compromises such studies. To avoid this problem we utilized pest Lepidoptera, cabbage looper (Trichoplusia ni) and fall armyworm (Spodoptera frugiperda), that were resistant to Cry1Ac produced in Bt broccoli (T. ni), Cry1Ac/Cry2Ab produced in Bt cotton (T. ni), and Cry1F produced in Bt maize (S. frugiperda). Larvae of these species were fed Bt plants or non-Bt plants and then exposed to predaceous larvae of the green lacewing Chrysoperla rufilabris. Fitness parameters (larval survival, development time, fecundity and egg hatch) of C. rufilabris were assessed over two generations. There were no differences in any of the fitness parameters regardless if C. rufilabris consumed prey (T. ni or S. frugiperda) that had consumed Bt or non-Bt plants. Additional studies confirmed that the prey contained bioactive Cry proteins when they were consumed by the predator. These studies confirm that Cry1Ac, Cry2Ab and Cry1F do not pose a hazard to the important predator C. rufilabris. This study also demonstrates the power of using resistant hosts when assessing the risk of genetically modified plants on non-target organisms. PMID:23544126

  3. Overexpression of the Bacillus thuringiensis (Bt) Cry2Aa2 protein in chloroplasts confers resistance to plants against susceptible and Bt-resistant insects

    PubMed Central

    Kota, Madhuri; Daniell, Henry; Varma, Sam; Garczynski, Stephen F.; Gould, Fred; Moar, William J.

    1999-01-01

    Evolving levels of resistance in insects to the bioinsecticide Bacillus thuringiensis (Bt) can be dramatically reduced through the genetic engineering of chloroplasts in plants. When transgenic tobacco leaves expressing Cry2Aa2 protoxin in chloroplasts were fed to susceptible, Cry1A-resistant (20,000- to 40,000-fold) and Cry2Aa2-resistant (330- to 393-fold) tobacco budworm Heliothis virescens, cotton bollworm Helicoverpa zea, and the beet armyworm Spodoptera exigua, 100% mortality was observed against all insect species and strains. Cry2Aa2 was chosen for this study because of its toxicity to many economically important insect pests, relatively low levels of cross-resistance against Cry1A-resistant insects, and its expression as a protoxin instead of a toxin because of its relatively small size (65 kDa). Southern blot analysis confirmed stable integration of cry2Aa2 into all of the chloroplast genomes (5,000–10,000 copies per cell) of transgenic plants. Transformed tobacco leaves expressed Cry2Aa2 protoxin at levels between 2% and 3% of total soluble protein, 20- to 30-fold higher levels than current commercial nuclear transgenic plants. These results suggest that plants expressing high levels of a nonhomologous Bt protein should be able to overcome or at the very least, significantly delay, broad spectrum Bt-resistance development in the field. PMID:10051556

  4. Bt Toxin Modification for Enhanced Efficacy

    PubMed Central

    Deist, Benjamin R.; Rausch, Michael A.; Fernandez-Luna, Maria Teresa; Adang, Michael J.; Bonning, Bryony C.

    2014-01-01

    Insect-specific toxins derived from Bacillus thuringiensis (Bt) provide a valuable resource for pest suppression. Here we review the different strategies that have been employed to enhance toxicity against specific target species including those that have evolved resistance to Bt, or to modify the host range of Bt crystal (Cry) and cytolytic (Cyt) toxins. These strategies include toxin truncation, modification of protease cleavage sites, domain swapping, site-directed mutagenesis, peptide addition, and phage display screens for mutated toxins with enhanced activity. Toxin optimization provides a useful approach to extend the utility of these proteins for suppression of pests that exhibit low susceptibility to native Bt toxins, and to overcome field resistance. PMID:25340556

  5. Efficacy of insecticides of different chemistries against Helicoverpa zea (Lepidoptera: Noctuidae) in transgenic Bacillus thuringiensis and conventional cotton.

    PubMed

    Brickle, D S; Turnipseed, S G; Sullivan, M J

    2001-02-01

    Six insecticides of different chemistries were evaluated against the cotton bollworm, Helicoverpa zea (Boddie), in non-B.t. (Deltapine 'DP 5415', Deltapine 'DP 5415RR') and transgenic Bacillus thuringiensis (Berliner) (B.t.) (Deltapine 'NuCOTN 33B', Deltapine 'DP 458 B/RR') cotton. In 1998, treatments consisted of three rates each of a pyrethroid (lambda-cyhalothrin), spinosyn (spinosad), carbamate (thiodicarb), pyrrole (chlorfenapyr), oxadiazine (indoxacarb), and avermectin (emamectin benzoate) in a nonirrigated field. In 1999, treatments consisted of three rates each of lambda-cyhalothrin, spinosad, thiodicarb, and indoxacarb in an irrigated and a nonirrigated (dryland) field. The highest rate of each insecticide corresponded to normal grower-use rates. Spinosad and thiodicarb controlled H. zea in non-B.t. cotton, whereas other materials were less effective. Even though H. zea is becoming increasingly resistant to pyrethroid insecticides, lambda-cyhalothrin was highly effective in dryland B. thuringiensis cotton. Spinosad and thiodicarb were equally effective. Data indicated that reduced rates of lambda-cyhalothrin, spinosad, and thiodicarb could be used for control of H. zea in dryland B.t. cotton systems. However, reduced rates of these insecticides in a heavily irrigated B.t. cotton system did not provide adequate control. PMID:11233138

  6. Delaying corn rootworm resistance to Bt corn.

    PubMed

    Tabashnik, Bruce E; Gould, Fred

    2012-06-01

    Transgenic crops producing Bacillus thuringiensis (Bt) toxins for insect control have been successful, but their efficacy is reduced when pests evolve resistance. To delay pest resistance to Bt crops, the U.S. Environmental Protection Agency (EPA) has required refuges of host plants that do not produce Bt toxins to promote survival of susceptible pests. Such refuges are expected to be most effective if the Bt plants deliver a dose of toxin high enough to kill nearly all hybrid progeny produced by matings between resistant and susceptible pests. In 2003, the EPA first registered corn, Zea mays L., producing a Bt toxin (Cry3Bb1) that kills western corn rootworm, Diabrotica virgifera virgifera LeConte, one of the most economically important crop pests in the United States. The EPA requires minimum refuges of 20% for Cry3Bb1 corn and 5% for corn producing two Bt toxins active against corn rootworms. We conclude that the current refuge requirements are not adequate, because Bt corn hybrids active against corn rootworms do not meet the high-dose standard, and western corn rootworm has rapidly evolved resistance to Cry3Bb1 corn in the laboratory, greenhouse, and field. Accordingly, we recommend increasing the minimum refuge for Bt corn targeting corn rootworms to 50% for plants producing one toxin active against these pests and to 20% for plants producing two toxins active against these pests. Increasing the minimum refuge percentage can help to delay pest resistance, encourage integrated pest management, and promote more sustainable crop protection. PMID:22812111

  7. Using resistant prey demonstrates that Bt plants producing Cry1Ac, Cry2Ab, and Cry1F have no negative effects on Geocoris punctipes and Orius insidiosus.

    PubMed

    Tian, Jun-Ce; Long, Li-Ping; Wang, Xiang-Ping; Naranjo, Steven E; Romeis, Jörg; Hellmich, Richard L; Wang, Ping; Shelton, Anthony M

    2014-02-01

    Geocoris punctipes (Say) and Orius insidiosus (Say) are generalist predators found in a wide range of crops, including cotton (Gossypium hirsutum L.) and maize (Zea mays L.), where they provide important biological control services by feeding on an array of pests, including eggs and small larvae of caterpillars. A high percentage of cotton and maize in the United States and several other countries are transgenic cultivars that produce one or more of the insecticidal Cry proteins of Bacillus thuringiensis Berliner (Bt). Here we quantify effects of three Cry proteins on the life history of these predators over two generations when they are exposed to these Cry proteins indirectly through their prey. To eliminate the confounding prey quality effects that can be introduced by Bt-susceptible prey, we used Cry1Ac/Cry2Ab-resistant Trichoplusia ni (Hübner) and Cry1 F-resistant Spodoptera frugiperda (J.E. Smith) in a series of tri-trophic studies. Survival, development, adult mass, fecundity, and fertility were similar when predators consumed larvae feeding on Cry1Ac/Cry2Ab cotton or Cry1 F maize compared with prey feeding on isogenic or near-isogenic cotton or maize. Repeated exposure of the same initial cohort over a second generation also resulted in no differences in life-history traits when feeding on non-Bt- or Bt-fed prey. Enzyme-linked immunosorbent assay showed that predators were exposed to Bt Cry proteins from their prey and that these proteins became increasingly diluted as they moved up the food chain. Results show a clear lack of effect of three common and widespread Cry proteins on these two important predator species. The use of resistant insects to eliminate prey quality effects provides a robust and meaningful assessment of exposure and hazard. PMID:24472212

  8. Evaluating cotton stripper field performance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton strippers are used primarily in the Southern High Plains due to the specific cotton varieties grown. Typically, cotton strippers cost about two-thirds the price of a cotton picker and range from one-half to one-fourth the horsepower. A cotton stripper also has a higher field and harvesting ef...

  9. Effects of Bt maize-fed prey on the generalist predator Poecilus cupreus L. (Coleoptera: Carabidae).

    PubMed

    Meissle, Michael; Vojtech, Eva; Poppy, Guy M

    2005-04-01

    We investigated the effects of transgenic maize (Zea mays) expressing Bacillus thuringienses toxin (Bt maize) on larval and adult Poecilus cupreus carabid beetles in laboratory studies. In no-choice trials, neonate P. cupreus larvae were fed exclusively with Spodoptera littoralis caterpillars, which had been raised on Bt maize. S. littoralis raised on conventional maize or "high quality" Calliphora sp. pupae were fed to the beetle larvae in two control treatments. Bt-maize-fed caterpillar prey increased mortality to 100% within 40 days. The experiment was repeated with 10-day-old beetle larvae. Bt treatment resulted in fewer pupae than in both controls, and in a higher mortality than in the Calliphora control. S. littoralis was suitable as exclusive prey in no-choice tests, at least for 40 days, although prey quality seemed to be low compared to Calliphora pupae. The observed effects are most likely indirect effects due to further reduced nutritional prey quality. However, direct effects cannot be excluded. In the second part of the study, exposure of P. cupreus to Bt intoxicated prey was examined in paired-choice tests. Adult beetles were offered a choice between different prey conditions (frozen and thawed, freshly killed or living), prey types (S. littoralis caterpillars, Calliphora sp. pupae, cereal aphids) and prey treatments (raised on Bt or conventional maize). Living prey was preferred to frozen and dead prey. Caterpillars were only preferred to fly pupae and aphids when living. Prey treatment seemed to be least important for prey selection. The tests showed that P. cupreus ingested caterpillars readily and there was no evidence of them avoiding Bt containing prey, which means exposure in the field could occur. The presented protocols are a first step towards ecological risk assessment for carabid beetles. PMID:16022384

  10. Susceptibility to Bt proteins not required for Agrotis ipsilon aversion to Bt maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although Bacillus thuringiensis (Bt) maize has been widely adopted in diverse regions around the world, relatively little is known about the susceptibility and behavioral response of certain insect pests to Bt maize in countries where this maize is not currently cultivated. These are important facto...

  11. Decomposition of Bt and non-Bt corn hybrid residues in the field

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Results of one laboratory study indicated that six transgenic crops expressing the Cry1Ab insecticidal protein from Bacillus thuringiensis (Bt) decomposed at a slower rate than their respective non-Bt isolines. Consequently, litter decomposition rates, nitrogen cycling, and carbon pools may change i...

  12. Comparative production of Helicoverpa zea (Lepidoptera: Noctuidae) from transgenic cotton expressing either one or two Bacillus thuringiensis proteins with and without insecticide oversprays.

    PubMed

    Jackson, R E; Bradley, J R; Van Duyn, J W; Gould, F

    2004-10-01

    Transgenic cotton, Gossypium hirsutum (L.), expressing either one or two Bacillus thuringiensis ssp. kurstaki Berliner (Bt) proteins was compared with the conventional sister line in field experiments with regard to production of bollworm, Helicoverpa zea (Boddie), and bolls damaged by bollworm. The relative numbers of bollworms that developed on Bollgard (Monsanto Co., St. Louis, MO), Bollgard II (Monsanto Co.), and conventional cotton were estimated under nontreated conditions in 2000 and both insecticide-treated and nontreated conditions in 2001-2002 in North Carolina tests. Averaged across seven field studies under nontreated conditions, Bollgard cotton generated statistically similar numbers of large (L4-L5) bollworm larvae compared with the conventional variety; however, Bollgard cotton produced significantly fewer damaged bolls and bollworm adults than the conventional variety. Production of large larvae, damaged bolls, and adults was decreased dramatically by Bollgard II cotton as compared with Bollgard and conventional varieties. When comparing insecticide-treated and nontreated cotton genotypes, both Bt cotton sustained less boll damage than the conventional variety averaged across insecticide regimes; furthermore, Bollgard II cotton had fewer damaged bolls than the Bollgard variety. When averaged across cotton genotypes, pyrethroid oversprays reduced the numbers of damaged bolls compared with the nontreated cotton. Insecticide-treated Bollgard cotton, along with insecticide-treated and nontreated Bollgard II cotton reduced production of bollworm larvae, pupae, and adults. However, the addition of pyrethroid oversprays to Bollgard II cotton seemed to be the best resistance management strategy available for bollworm because no bollworms were capable of completing development under these conditions. PMID:15568364

  13. Comparison of the physiological characteristics of transgenic insect-resistant cotton and conventional lines

    PubMed Central

    Li, Xiaogang; Ding, Changfeng; Wang, Xingxiang; Liu, Biao

    2015-01-01

    The introduction of transgenic insect-resistant cotton into agricultural ecosystems has raised concerns regarding its ecological effects. Many studies have been conducted to compare the differences in characteristics between transgenic cotton and conventional counterparts. However, few studies have focused on the different responses of transgenic cotton to stress conditions, especially to the challenges of pathogens. The aim of this work is to determine the extent of variation in physiological characteristics between transgenic insect-resistant cotton and the conventional counterpart infected by cotton soil-borne pathogens. The results showed that the difference in genetic backgrounds is the main factor responsible for the effects on biochemical characteristics of transgenic cotton when incubating with cotton Fusarium oxysporum. However, genetic modification had a significantly greater influence on the stomatal structure of transgenic cotton than the effects of cotton genotypes. Our results highlight that the differences in genetic background and/or genetic modifications may introduce variations in physiological characteristics and should be considered to explore the potential unexpected ecological effects of transgenic cotton. PMID:25737015

  14. Effect of Larvae Treated with Mixed Biopesticide Bacillus thuringiensis - Abamectin on Sex Pheromone Communication System in Cotton Bollworm, Helicoverpa armigera

    PubMed Central

    Shen, Li-Ze; Chen, Peng-Zhou; Xu, Zhi-Hong; Deng, Jian-Yu; Harris, Marvin-K; Wanna, Ruchuon; Wang, Fu-Min; Zhou, Guo-Xin; Yao, Zhang-Liang

    2013-01-01

    Third instar larvae of the cotton bollworm (Helicoverpa armigera) were reared with artificial diet containing a Bacillus thuringiensis - abamectin (BtA) biopesticide mixture that resulted in 20% mortality (LD20). The adult male survivors from larvae treated with BtA exhibited a higher percentage of “orientation” than control males but lower percentages of “approaching” and “landing” in wind tunnel bioassays. Adult female survivors from larvae treated with BtA produced higher sex pheromone titers and displayed a lower calling percentage than control females. The ratio of Z-11-hexadecenal (Z11–16:Ald) and Z-9-hexadecenal (Z9–16:Ald) in BtA-treated females changed and coefficients of variation (CV) of Z11–16:Ald and Z9–16:Ald were expanded compared to control females. The peak circadian calling time of BtA-treated females occurred later than that of control females. In mating choice experiment, both control males and BtA-treated males preferred to mate with control females and a portion of the Bt-A treated males did not mate whereas all control males did. Our Data support that treatment of larvae with BtA had an effect on the sex pheromone communication system in surviving H.armigera moths that may contribute to assortative mating. PMID:23874751

  15. Cotton-based nonwovens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This article is an abbreviated description of a new cotton-based nonwovens research program at the Southern Regional Research Center, which is one of the four regional research centers of the Agricultural Research Service, U.S. Department of Agriculture. Since cotton is a significant cash crop inte...

  16. Cotton-based nonwovens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This article is an abbreviated description of a new cotton-based nonwovens research program at the Southern Regional Research Center, which is one of the four regional research centers of the Agricultural Research Service, U.S. Department of Agriculture. Since cotton is a significant cash crop inter...

  17. CottonDB Enhancement

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The cotton genome database, CottonDB, was developed under a United States Department of Agriculture (USDA) Agricultural Research Service (ARS) project as part of a national program to develop plant genome databases for all agricultural commodities. This first and most extensively used database for ...

  18. BELTWIDE COTTON QUALITY STUDY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A two year, belt-wide commercial cotton gin sampling project was initiated in 2005 for the 2005-06 and 2006-07 ginning seasons to assess the changes in upland cotton quality throughout the ginning process and the ginning season with the ultimate goal of identifying areas where improvements can be ma...

  19. Agrometeorology and cotton production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton is a deciduous, indeterminate perennial plant that is cultivated as an annual in modern production systems. While the amount of time that the ambient air temperature remains within an optimum range (approximately 15.5 to 32.2 degrees C) is a principal factor determining the pace of cotton gr...

  20. COTTON TRASH CONSTITUENTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A series of cotton plant trash samples were sequentially extracted using toluene, methanol, propanol, and water to detect botanical differences. The United States currently produces around 20 million bales of cotton that is subsequently classed (length, strength, fineness, color, and trash) for mar...

  1. Field Performance of Bt Eggplants (Solanum melongena L.) in the Philippines: Cry1Ac Expression and Control of the Eggplant Fruit and Shoot Borer (Leucinodes orbonalis Guenée).

    PubMed

    Hautea, Desiree M; Taylo, Lourdes D; Masanga, Anna Pauleen L; Sison, Maria Luz J; Narciso, Josefina O; Quilloy, Reynaldo B; Hautea, Randy A; Shotkoski, Frank A; Shelton, Anthony M

    2016-01-01

    Plants expressing Cry proteins from the bacterium, Bacillus thuringiensis (Bt), have become a major tactic for controlling insect pests in maize and cotton globally. However, there are few Bt vegetable crops. Eggplant (Solanum melongena) is a popular vegetable grown throughout Asia that is heavily treated with insecticides to control the eggplant fruit and shoot borer, Leucinodes orbonalis (EFSB). Herein we provide the first publicly available data on field performance in Asia of eggplant engineered to produce the Cry1Ac protein. Replicated field trials with five Bt eggplant open-pollinated (OP) lines from transformation event EE-1 and their non-Bt comparators were conducted over three cropping seasons in the Philippines from 2010-2012. Field trials documented levels of Cry1Ac protein expressed in plants and evaluated their efficacy against the primary target pest, EFSB. Cry1Ac concentrations ranged from 0.75-24.7 ppm dry weight with the highest in the terminal leaves (or shoots) and the lowest in the roots. Cry1Ac levels significantly increased from the vegetative to the reproductive stage. Bt eggplant lines demonstrated excellent control of EFSB. Pairwise analysis of means detected highly significant differences between Bt eggplant lines and their non-Bt comparators for all field efficacy parameters tested. Bt eggplant lines demonstrated high levels of control of EFSB shoot damage (98.6-100%) and fruit damage (98.1-99.7%) and reduced EFSB larval infestation (95.8-99.3%) under the most severe pest pressure during trial 2. Moths that emerged from larvae collected from Bt plants in the field and reared in their Bt eggplant hosts did not produce viable eggs or offspring. These results demonstrate that Bt eggplant lines containing Cry1Ac event EE-1 provide outstanding control of EFSB and can dramatically reduce the need for conventional insecticides. PMID:27322533

  2. Field Performance of Bt Eggplants (Solanum melongena L.) in the Philippines: Cry1Ac Expression and Control of the Eggplant Fruit and Shoot Borer (Leucinodes orbonalis Guenée)

    PubMed Central

    Hautea, Desiree M.; Taylo, Lourdes D.; Masanga, Anna Pauleen L.; Sison, Maria Luz J.; Narciso, Josefina O.; Quilloy, Reynaldo B.; Hautea, Randy A.; Shotkoski, Frank A.; Shelton, Anthony M.

    2016-01-01

    Plants expressing Cry proteins from the bacterium, Bacillus thuringiensis (Bt), have become a major tactic for controlling insect pests in maize and cotton globally. However, there are few Bt vegetable crops. Eggplant (Solanum melongena) is a popular vegetable grown throughout Asia that is heavily treated with insecticides to control the eggplant fruit and shoot borer, Leucinodes orbonalis (EFSB). Herein we provide the first publicly available data on field performance in Asia of eggplant engineered to produce the Cry1Ac protein. Replicated field trials with five Bt eggplant open-pollinated (OP) lines from transformation event EE-1 and their non-Bt comparators were conducted over three cropping seasons in the Philippines from 2010–2012. Field trials documented levels of Cry1Ac protein expressed in plants and evaluated their efficacy against the primary target pest, EFSB. Cry1Ac concentrations ranged from 0.75–24.7 ppm dry weight with the highest in the terminal leaves (or shoots) and the lowest in the roots. Cry1Ac levels significantly increased from the vegetative to the reproductive stage. Bt eggplant lines demonstrated excellent control of EFSB. Pairwise analysis of means detected highly significant differences between Bt eggplant lines and their non-Bt comparators for all field efficacy parameters tested. Bt eggplant lines demonstrated high levels of control of EFSB shoot damage (98.6–100%) and fruit damage (98.1–99.7%) and reduced EFSB larval infestation (95.8–99.3%) under the most severe pest pressure during trial 2. Moths that emerged from larvae collected from Bt plants in the field and reared in their Bt eggplant hosts did not produce viable eggs or offspring. These results demonstrate that Bt eggplant lines containing Cry1Ac event EE-1 provide outstanding control of EFSB and can dramatically reduce the need for conventional insecticides. PMID:27322533

  3. The Cry1Ab Protein Has Minor Effects on the Arbuscular Mycorrhizal Fungal Communities after Five Seasons of Continuous Bt Maize Cultivation.

    PubMed

    Zeng, Huilan; Tan, Fengxiao; Shu, Yinghua; Zhang, Yanyan; Feng, Yuanjiao; Wang, Jianwu

    2015-01-01

    The cultivation of genetically modified plants (GMP) has raised concerns regarding the plants' ecological safety. A greenhouse experiment was conducted to assess the impact of five seasons of continuous Bt (Bacillus thuringiensis) maize cultivation on the colonisation and community structure of the non-target organisms arbuscular mycorrhizal fungi (AMF) in the maize roots, bulk soils and rhizospheric soils using the terminal restriction fragment length polymorphism (T-RFLP) analysis of the 28S ribosomal DNA and sequencing methods. AMF colonisation was significantly higher in the two Bt maize lines that express Cry1Ab, 5422Bt1 (event Bt11) and 5422CBCL (MON810) than in the non-Bt isoline 5422. No significant differences were observed in the diversity of the AMF community between the roots, bulk soils and rhizospheric soils of the Bt and non-Bt maize cultivars. The AMF genus Glomus was dominant in most of the samples, as detected by DNA sequencing. A clustering analysis based on the DNA sequence data suggested that the sample types (i.e., the samples from the roots, bulk soils or rhizospheric soils) might have greater influence on the AMF community phylotypes than the maize cultivars. This study indicated that the Cry1Ab protein has minor effects on the AMF communities after five seasons of continuous Bt maize cultivation. PMID:26717324

  4. The Cry1Ab Protein Has Minor Effects on the Arbuscular Mycorrhizal Fungal Communities after Five Seasons of Continuous Bt Maize Cultivation

    PubMed Central

    Shu, Yinghua; Zhang, Yanyan; Feng, Yuanjiao; Wang, Jianwu

    2015-01-01

    The cultivation of genetically modified plants (GMP) has raised concerns regarding the plants’ ecological safety. A greenhouse experiment was conducted to assess the impact of five seasons of continuous Bt (Bacillus thuringiensis) maize cultivation on the colonisation and community structure of the non-target organisms arbuscular mycorrhizal fungi (AMF) in the maize roots, bulk soils and rhizospheric soils using the terminal restriction fragment length polymorphism (T-RFLP) analysis of the 28S ribosomal DNA and sequencing methods. AMF colonisation was significantly higher in the two Bt maize lines that express Cry1Ab, 5422Bt1 (event Bt11) and 5422CBCL (MON810) than in the non-Bt isoline 5422. No significant differences were observed in the diversity of the AMF community between the roots, bulk soils and rhizospheric soils of the Bt and non-Bt maize cultivars. The AMF genus Glomus was dominant in most of the samples, as detected by DNA sequencing. A clustering analysis based on the DNA sequence data suggested that the sample types (i.e., the samples from the roots, bulk soils or rhizospheric soils) might have greater influence on the AMF community phylotypes than the maize cultivars. This study indicated that the Cry1Ab protein has minor effects on the AMF communities after five seasons of continuous Bt maize cultivation. PMID:26717324

  5. Binding and Oligomerization of Modified and Native Bt Toxins in Resistant and Susceptible Pink Bollworm

    PubMed Central

    Ocelotl, Josue; Sánchez, Jorge; Arroyo, Raquel; García-Gómez, Blanca I.; Gómez, Isabel; Unnithan, Gopalan C.; Tabashnik, Bruce E.; Bravo, Alejandra; Soberón, Mario

    2015-01-01

    Insecticidal proteins from Bacillus thuringiensis (Bt) are used extensively in sprays and transgenic crops for pest control, but their efficacy is reduced when pests evolve resistance. Better understanding of the mode of action of Bt toxins and the mechanisms of insect resistance is needed to enhance the durability of these important alternatives to conventional insecticides. Mode of action models agree that binding of Bt toxins to midgut proteins such as cadherin is essential for toxicity, but some details remain unresolved, such as the role of toxin oligomers. In this study, we evaluated how Bt toxin Cry1Ac and its genetically engineered counterpart Cry1AcMod interact with brush border membrane vesicles (BBMV) from resistant and susceptible larvae of Pectinophora gossypiella (pink bollworm), a global pest of cotton. Compared with Cry1Ac, Cry1AcMod lacks 56 amino acids at the amino-terminus including helix α-1; previous work showed that Cry1AcMod formed oligomers in vitro without cadherin and killed P. gossypiella larvae harboring cadherin mutations linked with >1000-fold resistance to Cry1Ac. Here we found that resistance to Cry1Ac was associated with reduced oligomer formation and insertion. In contrast, Cry1AcMod formed oligomers in BBMV from resistant larvae. These results confirm the role of cadherin in oligomerization of Cry1Ac in susceptible larvae and imply that forming oligomers without cadherin promotes toxicity of Cry1AcMod against resistant P. gossypiella larvae that have cadherin mutations. PMID:26633693

  6. Superhydrophobic antibacterial cotton textiles.

    PubMed

    Shateri Khalil-Abad, Mohammad; Yazdanshenas, Mohammad E

    2010-11-01

    We present a facile and effective method to prepare superhydrophobic cotton textiles. Silver particles were produced on cotton fibers by treatment with aqueous KOH and AgNO(3), followed by reduction treatment with ascorbic acid in the presence of a polymeric steric stabilizer to generate a dual-size surface roughness. Further modification of the particle-containing cotton textiles with octyltriethoxysilane led to hydrophobic surfaces. Surfaces prepared showed a sticky property, which exhibits a static water contact angle of 151 degrees for a 10 microL droplet that water drop did not slid off even when the sample was held upside down. The modified cotton has potent antibacterial activity toward both Gram-positive and Gram-negative bacteria. The Ag particles were uniformly and stably distributed on the substrate surface and killed bacteria. These modified cotton textiles are potentially useful; as superhydrophobic antibacterial fabrics in a wide variety of biomedical and general use applications. PMID:20709327

  7. Can Pyramids and Seed Mixtures Delay Resistance to Bt Crops?

    PubMed

    Carrière, Yves; Fabrick, Jeffrey A; Tabashnik, Bruce E

    2016-04-01

    The primary strategy for delaying the evolution of pest resistance to transgenic crops that produce insecticidal proteins from Bacillus thuringiensis (Bt) entails refuges of plants that do not produce Bt toxins and thus allow survival of susceptible pests. Recent advances include using refuges together with Bt crop 'pyramids' that make two or more Bt toxins effective against the same pest, and planting seed mixtures yielding random distributions of pyramided Bt and non-Bt corn plants within fields. We conclude that conditions often deviate from those favoring the success of pyramids and seed mixtures, particularly against pests with low inherent susceptibility to Bt toxins. For these problematic pests, promising approaches include using larger refuges and integrating Bt crops with other pest management tactics. PMID:26774592

  8. Dictionary of cotton: Picking & ginning

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton is an essential commodity for textiles and has long been an important item of trade in the world’s economy. Cotton is currently grown in over 100 countries by an estimated 100 producers. The basic unit of the cotton trade is the cotton bale which consists of approximately 500 pounds of raw c...

  9. Cotton source/sink relationships

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Metabolite source/sink relationships govern assimilate partitioning, developmental rates and fruit abscission in cotton. This subject is, therefore, of primary importance in the improvement of cotton plant types and in cotton culture. Historically, cotton has been among the most valuable of agrono...

  10. Dusky sap beetles (Coleoptera: Nitidulidae) and other kernel damaging insects in Bt and non-Bt sweet corn in Illinois.

    PubMed

    Dowd, P F

    2000-12-01

    Bt and non-Bt sweet corn hybrids (Rogers 'Empire' Bt and non-Bt, respectively) were compared for distribution of kernel damaging insect pests in central Illinois in 1998 and 1999. The occurrence and damage by caterpillars [primarily Helicoverpa zea (Boddie)] were reduced by at least 80% in each year for the Bt compared with the non-Bt hybrid. However, the incidence of sap beetle adults (primarily Carpophilus lugubris Murray) was higher, and larvae, lower for the Bt versus non-Bt in 1999. The incidence of ears with more than five kernels damaged by sap beetles was higher for the Bt compared with non-Bt hybrid in 1998 (13.8 versus 5.5%), but nearly equivalent in 1999 (15.3 versus 15.1%, respectively). Distribution of predators on plants (primarily Coccinelidae) and harvested ears (primarily Orius spp.) were not significantly different on Bt versus non-Bt hybrids. Ears with husks flush with the ear tip or with ear tips exposed had significantly higher sap beetle damage for both hybrids, and the Bt hybrids had significantly higher incidence of exposed ear tips in both years. Sap beetle numbers determined by scouting were often proportional to numbers of beetles captured in baited traps, increasing and decreasing at about the same time. However, values determined with traps were typically less variable than when scouted, and time of sampling was typically four times more rapid for each trap than for each 10 plant scout sample when measured in 1999. PMID:11142303

  11. Use and impact of Bt maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This is an invited article for a free science library and personal training tool sponsored by Nature Publishing Group, which will be included under the topics Agriculture and Biotechnology (http://www.nature.com/scitable). The focus of this article is on Bacillus thuringiensis (Bt) maize. Growers of...

  12. Risk Assessment and Stewardship of Bt Crops

    EPA Science Inventory

    Registration of Bt crops as part of the FIFRA requirements involves the assessment of environmental risk associated with the new crop variety. The assessment analysis stipulates that the seed producer provide clear and unambiguous information relating to certain risk categories a...

  13. A Toxin-Binding Alkaline Phosphatase Fragment Synergizes Bt Toxin Cry1Ac against Susceptible and Resistant Helicoverpa armigera

    PubMed Central

    Xiao, Yutao; Zhang, Dandan; Zhang, Yongdong; Li, Xianchun; Tabashnik, Bruce E.; Wu, Kongming

    2015-01-01

    Evolution of resistance by insects threatens the continued success of pest control using insecticidal crystal (Cry) proteins from the bacterium Bacillus thuringiensis (Bt) in sprays and transgenic plants. In this study, laboratory selection with Cry1Ac yielded five strains of cotton bollworm, Helicoverpa armigera, with resistance ratios at the median lethal concentration (LC50) of activated Cry1Ac ranging from 22 to 1700. Reduced activity and reduced transcription of an alkaline phosphatase protein that binds Cry1Ac was associated with resistance to Cry1Ac in the four most resistant strains. A Cry1Ac-binding fragment of alkaline phosphatase from H. armigera (HaALP1f) was not toxic by itself, but it increased mortality caused by Cry1Ac in a susceptible strain and in all five resistant strains. Although synergism of Bt toxins against susceptible insects by toxin-binding fragments of cadherin and aminopeptidase N has been reported previously, the results here provide the first evidence of synergism of a Bt toxin by a toxin-binding fragment of alkaline phosphatase. The results here also provide the first evidence of synergism of a Bt toxin by any toxin-binding peptide against resistant insects. PMID:25885820

  14. Roles of insect midgut cadherin in Bt intoxication and resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetically engineered crops producing Bacillus thuringiensis (Bt) proteins for insect control target major insect pests. Bt crops have improved yield and reduced risks associated with conventional insecticides; however, the evolution of resistance to Bt toxins by target pests threatens the long-ter...

  15. Potential application of entomopathogens in resistance management for Bt crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Adaptation by pest insects to the bacterium Bacillus thuringiensis (Bt) can alter their susceptibility to other pathogens. As the number of acres planted in crops engineered to produce Bt toxin increases, many key agricultural pests are under strong selection to evolve resistance to Bt. In conjunc...

  16. A Critical Assessment of the Effects of Bt Transgenic Plants on Parasitoids

    PubMed Central

    Chen, Mao; Zhao, Jian-Zhou; Collins, Hilda L.; Earle, Elizabeth D.; Cao, Jun; Shelton, Anthony M.

    2008-01-01

    The ecological safety of transgenic insecticidal plants expressing crystal proteins (Cry toxins) from the bacterium Bacillus thuringiensis (Bt) continues to be debated. Much of the debate has focused on nontarget organisms, especially predators and parasitoids that help control populations of pest insects in many crops. Although many studies have been conducted on predators, few reports have examined parasitoids but some of them have reported negative impacts. None of the previous reports were able to clearly characterize the cause of the negative impact. In order to provide a critical assessment, we used a novel paradigm consisting of a strain of the insect pest, Plutella xylostella (herbivore), resistant to Cry1C and allowed it to feed on Bt plants and then become parasitized by Diadegma insulare, an important endoparasitoid of P. xylostella. Our results indicated that the parasitoid was exposed to a biologically active form of the Cy1C protein while in the host but was not harmed by such exposure. Parallel studies conducted with several commonly used insecticides indicated they significantly reduced parasitism rates on strains of P. xylostella resistant to these insecticides. These results provide the first clear evidence of the lack of hazard to a parasitoid by a Bt plant, compared to traditional insecticides, and describe a test to rigorously evaluate the risks Bt plants pose to predators and parasitoids. PMID:18523682

  17. ASSESSING CHANGES IN SOIL MICROBIAL COMMUNITIES AND CARBON MINERALIZATION IN BT AND NON-BT CORN RESIDUE-AMENDED SOILS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of Bt corn (Zea mays L.) residue on soil microbial communities and rates of C mineralization were investigated. The Bt corn residue had a higher lignin content (12%) and lignin/N (9.9) ratio compared with its non-Bt near-isoline (10% lignin; lignin/N = 8.6). We examined the relationships...

  18. Frequency of alleles conferring resistance to the Bt toxins Cry1Ac and Cry2Ab in Australian populations of Helicoverpa armigera (Lepidoptera: Noctuidae).

    PubMed

    Mahon, R J; Olsen, K M; Downes, S; Addison, S

    2007-12-01

    Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is an important lepidopteran pest of cotton (Gossypium spp.) in Australia and the Old World. From 2002, F2 screens were used to examine the frequency of resistance alleles in Australian populations of H. armigera to Bacillus thuringiensis (Bt) CrylAc and Cry2Ab, the two insecticidal proteins present in the transgenic cotton Bollgard II. At that time, Ingard (expressing Cry1Ac) cotton had been grown in Australia for seven seasons, and Bollgard II was about to be commercially released. The principal objective of our study was to determine whether sustained exposure caused an elevated frequency of alleles conferring resistance to Cry1Ac in a species with a track record of evolving resistance to conventional insecticides. No major alleles conferring resistance to Cry1Ac were found. The frequency of resistance alleles for Cry1Ac was <0.0003, with a 95% credibility interval between 0 and 0.0009. In contrast, alleles conferring resistance to Cry2Ab were found at a frequency of 0.0033 (0.0017, 0.0055). The first isolation of this allele was found before the widespread deployment of Bollgard II. For both toxins the experiment-wise detection probability was 94.4%. Our results suggest that alleles conferring resistance to Cry1Ac are rare and that a relatively high baseline frequency of alleles conferring resistance to Cry2Ab existed before the introduction of Bt cotton containing this toxin. PMID:18232402

  19. Natural Enemies Delay Insect Resistance to Bt Crops

    PubMed Central

    Liu, Xiaoxia; Chen, Mao; Collins, Hilda L.; Onstad, David W.; Roush, Richard T.; Zhang, Qingwen; Earle, Elizabeth D.; Shelton, Anthony M.

    2014-01-01

    We investigated whether development of resistance to a Bt crop in the presence of a natural enemy would be slower than without the natural enemy and whether biological control, in conjunction with a Bt crop, could effectively suppress the pest population. Additionally, we investigated whether insecticide-sprayed refuges of non-Bt crops would delay or accelerate resistance to the Bt crop. We used a system of Bt broccoli expressing Cry1Ac, a population of the pest Plutella xylostella with a low frequency of individuals resistant to Cry1Ac and the insecticide spinosad, and a natural enemy, Coleomegilla maculata, to conduct experiments over multiple generations. The results demonstrated that after 6 generations P. xylostella populations were very low in the treatment containing C. maculata and unsprayed non-Bt refuge plants. Furthermore, resistance to Bt plants evolved significantly slower in this treatment. In contrast, Bt plants with no refuge were completely defoliated in treatments without C. maculata after 4–5 generations. In the treatment containing sprayed non-Bt refuge plants and C. maculata, the P. xylostella population was low, although the speed of resistance selection to Cry1Ac was significantly increased. These data demonstrate that natural enemies can delay resistance to Bt plants and have significant implications for integrated pest management (IPM) with Bt crops. PMID:24595158

  20. BT's adoption of customer centric design.

    PubMed

    Chamberlain, Mark; Esquivel, Jacqueline; Miller, Fiona; Patmore, Jeff

    2015-01-01

    Between 2005 and 2010 BT underwent a major transformation from a company with a special section devoted to 'older and disabled consumers' to a company with an inclusive design strategy. The mainstreaming of these issues responded to a demand for better, more user-friendly communications products and growing awareness of the importance of previously marginalised consumer groups. It also took place alongside the development and publication of BS7000-6, a guide to inclusive design management. Based on several product design case studies, this paper reflects on how and why this transformation was seen as necessary for future success, and how the transformation was achieved. The evolution of BT's approach has continued since, but this paper looks back in time, and documents the transformation up to 2010 and reflects the state of the company in 2010 rather than at the time of publication. PMID:24268467

  1. ALTERNATIVE COTTON HARVEST PREPARATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Organic production practices, urban encroachment and the presence of certain protected crops on adjacent fields presently restrict the use of defoliant chemicals in some cotton acreage. New legislation or stricter interpretation of existing environmental regulations may greatly increase the amount ...

  2. Superoleophobic cotton textiles.

    PubMed

    Leng, Boxun; Shao, Zhengzhong; de With, Gijsbertus; Ming, Weihua

    2009-02-17

    Common cotton textiles are hydrophilic and oleophilic in nature. Superhydrophobic cotton textiles have the potential to be used as self-cleaning fabrics, but they typically are not super oil-repellent. Poor oil repellency may easily compromise the self-cleaning property of these fabrics. Here, we report on the preparation of superoleophobic cotton textiles based on a multilength-scale structure, as demonstrated by a high hexadecane contact angle (153 degrees for 5 microL droplets) and low roll-off angle (9 degrees for 20 microL droplets). The multilength-scale roughness was based on the woven structure, with additional two layers of silica particles (microparticles and nanoparticles, respectively) covalently bonded to the fiber. Superoleophobicity was successfully obtained by incorporating perfluoroalkyl groups onto the surface of the modified cotton. It proved to be essential to add the nanoparticle layer in achieving superoleophobicity, especially in terms of low roll-off angles for hexadecane. PMID:19199744

  3. A nebula around Nova BT Monocerotis

    NASA Technical Reports Server (NTRS)

    Marsh, T. R.; Oke, J. B.; Wade, R. A.

    1983-01-01

    H-alpha observations of Nova BT Mon obtained on December 15, 1981 using an 800x800-pixel CCD detector on the double spectrograph of the 5-m Hale telescope at Palomar Observatory are reported. The reciprocal dispersion at H-alpha was 6.04 A/pixel and the angular scale along the 1.0-arcsec-wide east-west slit was 0.58 arcsec/pixel; resolution of the combined, processed image is about 12 A. A ring-shaped nebular emission with a center displaced slightly from the stellar image and an expansion distance to BT Mon of about 1800 pc was detected. The velocity diameter is found to be about 1500 km/sec along the ridge line and 2100 km/sec along the 10-unit contour. The mass of the visible nebula is estimated as 0.00003 solar mass, similar to the BT Mon ejection mass determined by Schaefer and Patterson (1983).

  4. 7 CFR 1205.304 - Cotton.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Cotton. 1205.304 Section 1205.304 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.304 Cotton. Cotton means: (a) All Upland cotton...

  5. 7 CFR 1205.304 - Cotton.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Cotton. 1205.304 Section 1205.304 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.304 Cotton. Cotton means: (a) All Upland cotton...

  6. 7 CFR 1205.304 - Cotton.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Cotton. 1205.304 Section 1205.304 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.304 Cotton. Cotton means: (a) All Upland cotton...

  7. 7 CFR 1205.304 - Cotton.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Cotton. 1205.304 Section 1205.304 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.304 Cotton. Cotton means: (a) All Upland cotton...

  8. 7 CFR 1205.304 - Cotton.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Cotton. 1205.304 Section 1205.304 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.304 Cotton. Cotton means: (a) All Upland cotton...

  9. FLAMMABILITY OF COTTON GIN TRASH/BURRS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seed cotton is removed from the field by a harvester and taken to the cotton gin to finish the harvesting process by separating the incoming seed cotton into four products: cotton fiber/lint, cottonseed, motes and cotton gin trash. Disposal of the cotton gin trash/burrs can be accomplished by sprea...

  10. Production and characterization of Bacillus thuringiensis Cry1Ac-resistant cotton bollworm Helicoverpa zea (Boddie).

    PubMed

    Anilkumar, Konasale J; Rodrigo-Simón, Ana; Ferré, Juan; Pusztai-Carey, Marianne; Sivasupramaniam, Sakuntala; Moar, William J

    2008-01-01

    Laboratory-selected Bacillus thuringiensis-resistant colonies are important tools for elucidating B. thuringiensis resistance mechanisms. However, cotton bollworm, Helicoverpa zea, a target pest of transgenic corn and cotton expressing B. thuringiensis Cry1Ac (Bt corn and cotton), has proven difficult to select for stable resistance. Two populations of H. zea (AR and MR), resistant to the B. thuringiensis protein found in all commercial Bt cotton varieties (Cry1Ac), were established by selection with Cry1Ac activated toxin (AR) or MVP II (MR). Cry1Ac toxin reflects the form ingested by H. zea when feeding on Bt cotton, whereas MVP II is a Cry1Ac formulation used for resistance selection and monitoring. The resistance ratio (RR) for AR exceeded 100-fold after 11 generations and has been maintained at this level for nine generations. This is the first report of stable Cry1Ac resistance in H. zea. MR crashed after 11 generations, reaching only an RR of 12. AR was only partially cross-resistant to MVP II, suggesting that MVP II does not have the same Cry1Ac selection pressure as Cry1Ac toxin against H. zea and that proteases may be involved with resistance. AR was highly cross-resistant to Cry1Ab toxin but only slightly cross-resistant to Cry1Ab expressing corn leaf powder. AR was not cross-resistant to Cry2Aa2, Cry2Ab2-expressing corn leaf powder, Vip3A, and cypermethrin. Toxin-binding assays showed no significant differences, indicating that resistance was not linked to a reduction in binding. These results aid in understanding why this pest has not evolved B. thuringiensis resistance, and highlight the need to choose carefully the form of B. thuringiensis protein used in experiments. PMID:18024681

  11. Transgene Expression and Bt Protein Content in Transgenic Bt Maize (MON810) under Optimal and Stressful Environmental Conditions

    PubMed Central

    Trtikova, Miluse; Wikmark, Odd Gunnar; Zemp, Niklaus; Widmer, Alex; Hilbeck, Angelika

    2015-01-01

    Bt protein content in transgenic insect resistant (Bt) maize may vary between tissues within plants and between plants growing under different environmental conditions. However, it is unknown whether and how Bt protein content correlates with transgene expression, and whether this relationship is influenced by stressful environmental conditions. Two Bt maize varieties containing the same transgene cassette (MON 810) were grown under optimal and stressful conditions. Before and during stress exposure, the upper leaves were analysed for transgene expression using quantitative RT-PCR and for Bt content using ELISA. Under optimal conditions there was no significant difference in the transgene expression between the two investigated Bt maize varieties whereas Bt protein content differed significantly. Transgene expression was correlated with Bt protein content in only one of the varieties. Under stressful environmental conditions we found similar transgene expressions as under optimal conditions but Bt content responded differently. These results suggest that Bt content is not only controlled by the transgene expression but is also dependent on the genetic background of the maize variety. Under stressful conditions the concentration of Bt protein is even more difficult to predict. PMID:25853814

  12. Transgene expression and Bt protein content in transgenic Bt maize (MON810) under optimal and stressful environmental conditions.

    PubMed

    Trtikova, Miluse; Wikmark, Odd Gunnar; Zemp, Niklaus; Widmer, Alex; Hilbeck, Angelika

    2015-01-01

    Bt protein content in transgenic insect resistant (Bt) maize may vary between tissues within plants and between plants growing under different environmental conditions. However, it is unknown whether and how Bt protein content correlates with transgene expression, and whether this relationship is influenced by stressful environmental conditions. Two Bt maize varieties containing the same transgene cassette (MON 810) were grown under optimal and stressful conditions. Before and during stress exposure, the upper leaves were analysed for transgene expression using quantitative RT-PCR and for Bt content using ELISA. Under optimal conditions there was no significant difference in the transgene expression between the two investigated Bt maize varieties whereas Bt protein content differed significantly. Transgene expression was correlated with Bt protein content in only one of the varieties. Under stressful environmental conditions we found similar transgene expressions as under optimal conditions but Bt content responded differently. These results suggest that Bt content is not only controlled by the transgene expression but is also dependent on the genetic background of the maize variety. Under stressful conditions the concentration of Bt protein is even more difficult to predict. PMID:25853814

  13. Effects of Transgenic Cry1Ac + CpTI Cotton on Non-Target Mealybug Pest Ferrisia virgata and Its Predator Cryptolaemus montrouzieri

    PubMed Central

    Wu, Hongsheng; Zhang, Yuhong; Liu, Ping; Xie, Jiaqin; He, Yunyu; Deng, Congshuang; De Clercq, Patrick; Pang, Hong

    2014-01-01

    Recently, several invasive mealybugs (Hemiptera: Pseudococcidae) have rapidly spread to Asia and have become a serious threat to the production of cotton including transgenic cotton. Thus far, studies have mainly focused on the effects of mealybugs on non-transgenic cotton, without fully considering their effects on transgenic cotton and trophic interactions. Therefore, investigating the potential effects of mealybugs on transgenic cotton and their key natural enemies is vitally important. A first study on the effects of transgenic cotton on a non-target mealybug, Ferrisia virgata (Cockerell) (Hemiptera: Pseudococcidae) was performed by comparing its development, survival and body weight on transgenic cotton leaves expressing Cry1Ac (Bt toxin) + CpTI (Cowpea Trypsin Inhibitor) with those on its near-isogenic non-transgenic line. Furthermore, the development, survival, body weight, fecundity, adult longevity and feeding preference of the mealybug predator Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae) was assessed when fed F. virgata maintained on transgenic cotton. In order to investigate potential transfer of Cry1Ac and CpTI proteins via the food chain, protein levels in cotton leaves, mealybugs and ladybirds were quantified. Experimental results showed that F. virgata could infest this bivalent transgenic cotton. No significant differences were observed in the physiological parameters of the predator C. montrouzieri offered F. virgata reared on transgenic cotton or its near-isogenic line. Cry1Ac and CpTI proteins were detected in transgenic cotton leaves, but no detectable levels of both proteins were present in the mealybug or its predator when reared on transgenic cotton leaves. Our bioassays indicated that transgenic cotton poses a negligible risk to the predatory coccinellid C. montrouzieri via its prey, the mealybug F. virgata. PMID:24751821

  14. Cotton and Protein Interactions

    SciTech Connect

    Goheen, Steven C.; Edwards, J. V.; Rayburn, Alfred R.; Gaither, Kari A.; Castro, Nathan J.

    2006-06-30

    The adsorbent properties of important wound fluid proteins and cotton cellulose are reviewed. This review focuses on the adsorption of albumin to cotton-based wound dressings and some chemically modified derivatives targeted for chronic wounds. Adsorption of elastase in the presence of albumin was examined as a model to understand the interactive properties of these wound fluid components with cotton fibers. In the chronic non-healing wound, elastase appears to be over-expressed, and it digests tissue and growth factors, interfering with the normal healing process. Albumin is the most prevalent protein in wound fluid, and in highly to moderately exudative wounds, it may bind significantly to the fibers of wound dressings. Thus, the relative binding properties of both elastase and albumin to wound dressing fibers are of interest in the design of more effective wound dressings. The present work examines the binding of albumin to two different derivatives of cotton, and quantifies the elastase binding to the same derivatives following exposure of albumin to the fiber surface. An HPLC adsorption technique was employed coupled with a colorimetric enzyme assay to quantify the relative binding properties of albumin and elastase to cotton. The results of wound protein binding are discussed in relation to the porosity and surface chemistry interactions of cotton and wound proteins. Studies are directed to understanding the implications of protein adsorption phenomena in terms of fiber-protein models that have implications for rationally designing dressings for chronic wounds.

  15. The interaction of two-spotted spider mites, Tetranychus urticae Koch, with Cry protein production and predation by Amblyseius andersoni (Chant) in Cry1Ac/Cry2Ab cotton and Cry1F maize.

    PubMed

    Guo, Yan-Yan; Tian, Jun-Ce; Shi, Wang-Peng; Dong, Xue-Hui; Romeis, Jörg; Naranjo, Steven E; Hellmich, Richard L; Shelton, Anthony M

    2016-02-01

    Crops producing insecticidal crystal (Cry) proteins from the bacterium, Bacillus thuringiensis (Bt), are an important tool for managing lepidopteran pests on cotton and maize. However, the effects of these Bt crops on non-target organisms, especially natural enemies that provide biological control services, are required to be addressed in an environmental risk assessment. Amblyseius andersoni (Acari: Phytoseiidae) is a cosmopolitan predator of the two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae), a significant pest of cotton and maize. Tri-trophic studies were conducted to assess the potential effects of Cry1Ac/Cry2Ab cotton and Cry1F maize on life history parameters (survival rate, development time, fecundity and egg hatching rate) of A. andersoni. We confirmed that these Bt crops have no effects on the biology of T. urticae and, in turn, that there were no differences in any of the life history parameters of A. andersoni when it fed on T. urticae feeding on Cry1Ac/Cry2Ab or non-Bt cotton and Cry1F or non-Bt maize. Use of a susceptible insect assay demonstrated that T. urticae contained biologically active Cry proteins. Cry proteins concentrations declined greatly as they moved from plants to herbivores to predators and protein concentration did not appear to be related to mite density. Free-choice experiments revealed that A. andersoni had no preference for Cry1Ac/Cry2Ab cotton or Cry1F maize-reared T. urticae compared with those reared on non-Bt cotton or maize. Collectively these results provide strong evidence that these crops can complement other integrated pest management tactics including biological control. PMID:26545599

  16. Diversity of Bacillus thuringiensis in the rice field soils of different ecologies in India.

    PubMed

    Das, J; Dangar, T K

    2007-12-01

    Diversity of the Bacillus thuringiensis (Bt) in the rice field soils of different ecologies viz. the island (Port Blair), the Himalayan (Srinagar), brackish water (Mahe) and coastal mesophilic (Mangalore) habitats was analyzed by phenotypic characterization of 5, 66, 14 and 54 Bt isolates, respectively. The Bt isolates produced either monotypic (bipyramidal or spherical) or heterotypic (polymorphic-bipyramidal or bipyramidal-rhomboidal) crystals. The organisms were generally resistant to the penicillin group of antibiotics, tolerated 5-12% NaCl and 0.5M Na-acetate. The Bt isolates contained 1-5 plasmids of 0.89-58.61 kbp sizes. The plasmid profiles had no correlation with crystal morphology or salt tolerance of different bacteria. Each soil was inhabited by different types of Bt. Two Bt strains of Mangalore and one strain each of the other places were phenotypically similar. One Bt strain each of Port Blair and Srinagar was different from all other strains. PMID:23100691

  17. 43. COTTON VACUUM, WHICH WAS USED TO MOVE COTTON INTO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    43. COTTON VACUUM, WHICH WAS USED TO MOVE COTTON INTO PICKER ROOM. 2nd FLOOR PICKER ROOM, MILL NO. 2. - Prattville Manufacturing Company, Number One, 242 South Court Street, Prattville, Autauga County, AL

  18. Testing Pollen of Single and Stacked Insect-Resistant Bt-Maize on In vitro Reared Honey Bee Larvae

    PubMed Central

    Hendriksma, Harmen P.; Härtel, Stephan; Steffan-Dewenter, Ingolf

    2011-01-01

    The ecologically and economic important honey bee (Apis mellifera) is a key non-target arthropod species in environmental risk assessment (ERA) of genetically modified (GM) crops. Honey bee larvae are directly exposed to transgenic products by the consumption of GM pollen. But most ERA studies only consider responses of adult bees, although Bt-proteins primarily affect the larval phases of target organisms. We adopted an in vitro larvae rearing system, to assess lethal and sublethal effects of Bt-pollen consumption in a standardized eco-toxicological bioassay. The effects of pollen from two Bt-maize cultivars, one expressing a single and the other a total of three Bt-proteins, on the survival and prepupae weight of honey bee larvae were analyzed. The control treatments included pollen from three non-transgenic maize varieties and of Heliconia rostrata. Three days old larvae were fed the realistic exposure dose of 2 mg pollen within the semi-artificial diet. The larvae were monitored over 120 h, until the prepupal stage, where larvae terminate feeding and growing. Neither single nor stacked Bt-maize pollen showed an adverse effect on larval survival and the prepupal weight. In contrast, feeding of H. rostrata pollen caused significant toxic effects. The results of this study indicate that pollen of the tested Bt-varieties does not harm the development of in vitro reared A. mellifera larvae. To sustain the ecosystem service of pollination, Bt-impact on A. mellifera should always be a crucial part of regulatory biosafety assessments. We suggest that our approach of feeding GM pollen on in vitro reared honey bee larvae is well suited of becoming a standard bioassay in regulatory risk assessments schemes of GM crops. PMID:22194811

  19. Testing pollen of single and stacked insect-resistant Bt-maize on in vitro reared honey bee larvae.

    PubMed

    Hendriksma, Harmen P; Härtel, Stephan; Steffan-Dewenter, Ingolf

    2011-01-01

    The ecologically and economic important honey bee (Apis mellifera) is a key non-target arthropod species in environmental risk assessment (ERA) of genetically modified (GM) crops. Honey bee larvae are directly exposed to transgenic products by the consumption of GM pollen. But most ERA studies only consider responses of adult bees, although Bt-proteins primarily affect the larval phases of target organisms. We adopted an in vitro larvae rearing system, to assess lethal and sublethal effects of Bt-pollen consumption in a standardized eco-toxicological bioassay. The effects of pollen from two Bt-maize cultivars, one expressing a single and the other a total of three Bt-proteins, on the survival and prepupae weight of honey bee larvae were analyzed. The control treatments included pollen from three non-transgenic maize varieties and of Heliconia rostrata. Three days old larvae were fed the realistic exposure dose of 2 mg pollen within the semi-artificial diet. The larvae were monitored over 120 h, until the prepupal stage, where larvae terminate feeding and growing. Neither single nor stacked Bt-maize pollen showed an adverse effect on larval survival and the prepupal weight. In contrast, feeding of H. rostrata pollen caused significant toxic effects. The results of this study indicate that pollen of the tested Bt-varieties does not harm the development of in vitro reared A. mellifera larvae. To sustain the ecosystem service of pollination, Bt-impact on A. mellifera should always be a crucial part of regulatory biosafety assessments. We suggest that our approach of feeding GM pollen on in vitro reared honey bee larvae is well suited of becoming a standard bioassay in regulatory risk assessments schemes of GM crops. PMID:22194811

  20. CottonDB: A database for cotton research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    CottonDB, established in 1995, was among the first plant genome databases established by the USDA-ARS. The goal of CottonDB is to serve both as an archival and a dynamic database that incorporates data from all major categories of genetic and genomic information created by the cotton research commu...

  1. CottonDB: A resource for cotton genome research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    CottonDB (http://cottondb.org/) is a database and web resource for cotton genomic and genetic research. Created in 1995, CottonDB was among the first plant genome databases established by the USDA-ARS. Accessed through a website interface, the database aims to be a convenient, inclusive medium of ...

  2. Mining cotton germplasm resources to fight Cotton Leaf Curl Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    CLCuV (Cotton Leaf Curl Virus) is a major threat to cotton production in Pakistan and parts of India and has been reported in cotton producing countries in Africa, as well as China and Uzbekistan. Identifying sources of resistance to CLCuV helps not only countries such as Pakistan where the virus is...

  3. Effect of larvae treated with mixed biopesticide Bacillus thuringiensis-abamectin on sex pheromone communication system in cotton bollworm, Helicoverpa armigera.

    PubMed

    Shen, Li-Ze; Chen, Peng-Zhou; Xu, Zhi-Hong; Deng, Jian-Yu; Harris, Marvin-K; Wanna, Ruchuon; Wang, Fu-Min; Zhou, Guo-Xin; Yao, Zhang-Liang

    2013-01-01

    Third instar larvae of the cotton bollworm (Helicoverpa armigera) were reared with artificial diet containing a Bacillus thuringiensis-abamectin (BtA) biopesticide mixture that resulted in 20% mortality (LD20). The adult male survivors from larvae treated with BtA exhibited a higher percentage of "orientation" than control males but lower percentages of "approaching" and "landing" in wind tunnel bioassays. Adult female survivors from larvae treated with BtA produced higher sex pheromone titers and displayed a lower calling percentage than control females. The ratio of Z-11-hexadecenal (Z11-16:Ald) and Z-9-hexadecenal (Z9-16:Ald) in BtA-treated females changed and coefficients of variation (CV) of Z11-16:Ald and Z9-16:Ald were expanded compared to control females. The peak circadian calling time of BtA-treated females occurred later than that of control females. In mating choice experiment, both control males and BtA-treated males preferred to mate with control females and a portion of the Bt-A treated males did not mate whereas all control males did. Our Data support that treatment of larvae with BtA had an effect on the sex pheromone communication system in surviving H. armigera moths that may contribute to assortative mating. PMID:23874751

  4. Picking Cotton - and Nothing Else

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The picking of cotton by mechanical means includes the collection of extensive foreign matter that seriously affects the cotton grade and thus the price per bale. Rapid identification of the nature of the extraneous matter in cotton at each stage of cleaning and processing is necessary to permit act...

  5. Advancements in Cotton Harvesting Research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton harvesting research within USDA ARS is focused on improving harvest productivity, cotton quality, and producer profitability. In recent years, our work has encompassed efforts to improve both spindle picker and brush-roll stripper harvesting systems. Specifically, work with cotton pickers i...

  6. TMD factorization and evolution at large $b_T$

    SciTech Connect

    Collins, John; Rogers, Ted

    2015-07-20

    In using transverse-momentum-dependent (TMD) parton densities and fragmentation functions, important non-perturbative information is at large transverse position $b_T$. This concerns both the TMD functions and their evolution. Fits to high energy data tend to predict too rapid evolution when extrapolated to low energies where larger values of $b_T$ dominate. I summarize a new analysis of the issues. It results in a proposal for much weaker $b_T$ dependence at large $b_T$ for the evolution kernel, while preserving the accuracy of the existing fits. The results are particularly important for using transverse-spin-dependent functions like the Sivers function.

  7. Effects of BT-11 on memory in healthy humans.

    PubMed

    Lee, Jun-Young; Kim, Ka Young; Shin, Ki Young; Won, Beom Young; Jung, Hee Yeon; Suh, Yoo-Hun

    2009-04-24

    We previously reported that BT-11, the extract of dried roots of Polygala tenuifolia Willdenow, had neuroprotective effects and improved scopolamine- and stress-induced amnesia in rats. It also blocked the activity of acetylcholinesterase and enhanced glucose utilization in the rat brain. Therefore, we examined whether BT-11 could enhance memory in healthy humans. This study was a randomized, double-blind, placebo-controlled, parallel-group study of BT-11 in healthy adults. The participants were given capsules of BT-11 or placebo 3 times daily for 4 weeks. The Korean version of the California Verbal Learning Test (K-CVLT) and the Self-Ordered Pointing Test (SOPT) were used to assess verbal memory and working memory, respectively. The subjects in BT-11-treated group showed more significant increases in immediate recall on the K-CVLT than those in the placebo-treated group. In a comparison within each group, the subjects' scores on most subtests of the K-CVLT were significantly increased by both placebo and BT-11 treatment. Interestingly, the subjects' scores on the recognition subtest of the K-CVLT were significantly increased by BT-11 treatment but not by placebo treatment. Also, BT-11 treatment significantly reduced the number of errors on the SOPT, whereas placebo treatment did not. We are the first to show that BT-11 has memory-enhancing effects and may be a memory-enhancing drug in healthy adults. PMID:19429065

  8. The development and status of Bt rice in China.

    PubMed

    Li, Yunhe; Hallerman, Eric M; Liu, Qingsong; Wu, Kongming; Peng, Yufa

    2016-03-01

    Multiple lines of transgenic rice expressing insecticidal genes from the bacterium Bacillus thuringiensis (Bt) have been developed in China, posing the prospect of increases in production with decreased application of pesticides. We explore the issues facing adoption of Bt rice for commercial production in China. A body of safety assessment work on Bt rice has shown that Bt rice poses a negligible risk to the environment and that Bt rice products are as safe as non-Bt control rice products as food. China has a relatively well-developed regulatory system for risk assessment and management of genetically modified (GM) plants; however, decision-making regarding approval of commercial production has become politicized, and two Bt rice lines that otherwise were ready have not been allowed to enter the Chinese agricultural system. We predict that Chinese farmers would value the prospect of increased yield with decreased use of pesticide and would readily adopt production of Bt rice. That Bt rice lines may not be commercialized in the near future we attribute to social pressures, largely due to the low level of understanding and acceptance of GM crops by Chinese consumers. Hence, enhancing communication of GM crop science-related issues to the public is an important, unmet need. While the dynamics of each issue are particular to China, they typify those in many countries where adoption of GM crops has been not been rapid; hence, the assessment of these dynamics might inform resolution of these issues in other countries. PMID:26369652

  9. Field Studies to Evaluate Potential Differences between Bt and non-Bt Corn Residue

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Some reports suggest that the genetically-modified Bt corn residue may have higher lignin content and that the residue may be more resistant to decomposition. If true, then there are implications for both farming practices, e.g., tillage and planting, as well as global carbon budgets. We conducted ...

  10. Field Studies to Evaluate Potential Differences between Bt and non-Bt Corn Residue

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Some reports suggest that the genetically-modified Bt corn residue may have higher lignin content and that the residue may be more resistant to decomposition. If true, then there are implications for both farming practices, e.g., tillage and planting, as well as global carbon budgets. We evaluated ...

  11. Food safety assessment of Cry8Ka5 mutant protein using Cry1Ac as a control Bt protein.

    PubMed

    Farias, Davi Felipe; Viana, Martônio Ponte; Oliveira, Gustavo Ramos; Santos, Vanessa Olinto; Pinto, Clidia Eduarda Moreira; Viana, Daniel Araújo; Vasconcelos, Ilka Maria; Grossi-de-Sa, Maria Fátima; Carvalho, Ana Fontenele Urano

    2015-07-01

    Cry8Ka5 is a mutant protein from Bacillus thuringiensis (Bt) that has been proposed for developing transgenic plants due to promising activity against coleopterans, like Anthonomus grandis (the major pest of Brazilian cotton culture). Thus, an early food safety assessment of Cry8Ka5 protein could provide valuable information to support its use as a harmless biotechnological tool. This study aimed to evaluate the food safety of Cry8Ka5 protein following the two-tiered approach, based on weights of evidence, proposed by ILSI. Cry1Ac protein was used as a control Bt protein. The history of safe use revealed no convincing hazard reports for Bt pesticides and three-domain Cry proteins. The bioinformatics analysis with the primary amino acids sequence of Cry8Ka5 showed no similarity to any known toxic, antinutritional or allergenic proteins. The mode of action of Cry proteins is well understood and their fine specificity is restricted to insects. Cry8Ka5 and Cry1Ac proteins were rapidly degraded in simulated gastric fluid, but were resistant to simulated intestinal fluid and heat treatment. The LD50 for Cry8Ka5 and Cry1Ac was >5000 mg/kg body weight when administered by gavage in mice. Thus, no expected relevant risks are associated with the consumption of Cry8Ka5 protein. PMID:25890087

  12. Field Evaluation of Arbuscular Mycorrhizal Fungal Colonization in Bacillus thuringiensis Toxin-Expressing (Bt) and Non-Bt Maize

    PubMed Central

    Cruzan, Mitchell B.; Rosenstiel, Todd N.

    2013-01-01

    The cultivation of genetically engineered Bacillus thuringiensis toxin-expressing (Bt) maize continues to increase worldwide, yet the effects of Bt crops on arbuscular mycorrhizal fungi (AMF) in soil are poorly understood. In this field experiment, we investigated the impact of seven different genotypes of Bt maize and five corresponding non-Bt parental cultivars on AMF and evaluated plant growth responses at three different physiological time points. Plants were harvested 60 days (active growth), 90 days (tasseling and starting to produce ears), and 130 days (maturity) after sowing, and data on plant growth responses and percent AMF colonization of roots at each harvest were collected. Spore abundance and diversity were also evaluated at the beginning and end of the field season to determine whether the cultivation of Bt maize had a negative effect on AMF propagules in the soil. Plant growth and AMF colonization did not differ between Bt and non-Bt maize at any harvest period, but AMF colonization was positively correlated with leaf chlorophyll content at the 130-day harvest. Cultivation of Bt maize had no effect on spore abundance and diversity in Bt versus non-Bt plots over one field season. Plot had the most significant effect on total spore counts, indicating spatial heterogeneity in the field. Although previous greenhouse studies demonstrated that AMF colonization was lower in some Bt maize lines, our field study did not yield the same results, suggesting that the cultivation of Bt maize may not have an impact on AMF in the soil ecosystem under field conditions. PMID:23624473

  13. Extrapolating non-target risk of Bt crops from laboratory to field.

    PubMed

    Duan, Jian J; Lundgren, Jonathan G; Naranjo, Steve; Marvier, Michelle

    2010-02-23

    The tiered approach to assessing ecological risk of insect-resistant transgenic crops assumes that lower tier laboratory studies, which expose surrogate non-target organisms to high doses of insecticidal proteins, can detect harmful effects that might be manifested in the field. To test this assumption, we performed meta-analyses comparing results for non-target invertebrates exposed to Bacillus thuringiensis (Bt) Cry proteins in laboratory studies with results derived from independent field studies examining effects on the abundance of non-target invertebrates. For Lepidopteran-active Cry proteins, laboratory studies correctly predicted the reduced field abundance of non-target Lepidoptera. However, laboratory studies incorporating tri-trophic interactions of Bt plants, herbivores and parasitoids were better correlated with the decreased field abundance of parasitoids than were direct-exposure assays. For predators, laboratory tri-trophic studies predicted reduced abundances that were not realized in field studies and thus overestimated ecological risk. Exposure to Coleopteran-active Cry proteins did not significantly reduce the laboratory survival or field abundance of any functional group examined. Our findings support the assumption that laboratory studies of transgenic insecticidal crops show effects that are either consistent with, or more conservative than, those found in field studies, with the important caveat that laboratory studies should explore all ecologically relevant routes of exposure. PMID:19740894

  14. Current trends in Bt crops and their fate on associated microbial community dynamics: a review.

    PubMed

    Singh, Amit Kishore; Dubey, Suresh Kumar

    2016-05-01

    Cry protein expressing insect-resistant trait is mostly deployed to control major devastating pests and minimize reliance on the conventional pesticides. However, the ethical and environmental issues are the major constraints in their acceptance, and consequently, the cultivation of genetically modified (GM) crops has invited intense debate. Since root exudates of Bacillus thuringiensis (Bt) crops harbor the insecticidal protein, there is a growing concern about the release and accumulation of soil-adsorbed Cry proteins and their impact on non-target microorganisms and soil microbial processes. This review pertains to reports from the laboratory studies and field trials to assess the Bt toxin proteins in soil microbes and the processes determining the soil quality in conjunction with the existing hypothesis and molecular approaches to elucidate the risk posed by the GM crops. Ecological perturbations hinder the risk aspect of soil microbiota in response to GM crops. Therefore, extensive research based on in vivo and interpretation of results using high-throughput techniques such as NGS on risk assessment are imperative to evaluate the impact of Bt crops to resolve the controversy related to their commercialization. But more studies are needed on the risk associated with stacked traits. Such studies would strengthen our knowledge about the plant-microbe interactions. PMID:26560114

  15. Understanding successful resistance management: the European corn borer and Bt corn in the United States.

    PubMed

    Siegfried, Blair D; Hellmich, Richard L

    2012-01-01

    The European corn borer, Ostrinia nubilalis Hübner (Lepidoptera: Crambidae) has been a major pest of corn and other crops in North America since its accidental introduction nearly a hundred years ago. Wide adoption of transgenic corn hybrids that express toxins from Bacillus thuringiensis, referred to as Bt corn, has suppressed corn borer populations and reduced the pest status of this insect in parts of the Corn Belt. Continued suppression of this pest, however, will depend on managing potential resistance to Bt corn, currently through the high-dose refuge (HDR) strategy. In this review, we describe what has been learned with regard to O. nubilalis resistance to Bt toxins either through laboratory selection experiments or isolation of resistance from field populations. We also describe the essential components of the HDR strategy as they relate to O. nubilalis biology and ecology. Additionally, recent developments in insect resistance management (IRM) specific to O. nubilalis that may affect the continued sustainability of this technology are considered. PMID:22688691

  16. 7 CFR 1205.308 - Cotton Board.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Cotton Board. 1205.308 Section 1205.308 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.308 Cotton Board. Cotton Board means the...

  17. 7 CFR 1205.308 - Cotton Board.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Cotton Board. 1205.308 Section 1205.308 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.308 Cotton Board. Cotton Board means the...

  18. 7 CFR 1205.308 - Cotton Board.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Cotton Board. 1205.308 Section 1205.308 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.308 Cotton Board. Cotton Board means the...

  19. 7 CFR 1205.308 - Cotton Board.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Cotton Board. 1205.308 Section 1205.308 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.308 Cotton Board. Cotton Board means the...

  20. 7 CFR 1205.308 - Cotton Board.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Cotton Board. 1205.308 Section 1205.308 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.308 Cotton Board. Cotton Board means the...

  1. 7 CFR 1205.305 - Upland cotton.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Upland cotton. 1205.305 Section 1205.305 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.305 Upland cotton. Upland cotton means all...

  2. 7 CFR 1205.305 - Upland cotton.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Upland cotton. 1205.305 Section 1205.305 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.305 Upland cotton. Upland cotton means all...

  3. 7 CFR 1205.305 - Upland cotton.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Upland cotton. 1205.305 Section 1205.305 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.305 Upland cotton. Upland cotton means all...

  4. 7 CFR 1205.305 - Upland cotton.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Upland cotton. 1205.305 Section 1205.305 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.305 Upland cotton. Upland cotton means all...

  5. 7 CFR 1205.305 - Upland cotton.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Upland cotton. 1205.305 Section 1205.305 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.305 Upland cotton. Upland cotton means all...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  7. Potential for Entomopathogens to Delay Resistance to Bt Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The past decade has witnessed a continual increase in the use of crops genetically modified to produce insecticidal toxins from the bacterium Bacillus thuringiensis (Bt). This presents the challenge of designing agricultural systems to manage pests and the evolution of resistance to Bt. Currently,...

  8. Challenges to monitoring Bt resistance in Helicoverpa zea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transgenic crops that produce insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) are widely grown in many countries for the control of lepidopteran pests. The evolution of resistance in these pests to transgenic crops producing Bt toxins threatens the prolonged success of this imp...

  9. Metal analysis of cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seven varieties of cotton were investigated for 8 metal ions (K, Na, Mg, Ca, Fe, Cu, Zn, and Mn) using Inductively Coupled Plasma-Optical Emission Spectroscopy. All of the varieties were grown at the same location. Half of the samples were dry (rain fed only) and the other were well-watered (irrigat...

  10. Cotton Pickin' Good Time.

    ERIC Educational Resources Information Center

    Gentry, Carol

    2000-01-01

    Describes the creation and development of a project at Lake Mary High School in Seminole County, Florida, in which students grew cotton in order to help them experience the production of the art material from the seed to the finished product. (CMK)

  11. Cotton thermal defoliation economics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton harvest-aid chemical and application expenses are justified by increased quantity and value of harvested fiber, and decreased harvest costs. Chemical use may be restricted in certain production situations. Harvest preparation costs and producer returns were compared for thermal defoliation ...

  12. Cotton Arthropod IPM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton is the world’s most important natural source of fiber, accounting for almost 40% of total worldwide production. The crop is grown in more than 75 countries with a total production in 2006 of 25.4 billion kg. The U.S. produced 21.7 million bales in 2006 in a diversity of production environmen...

  13. Competitive release and outbreaks of non-target pests associated with transgenic Bt cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study tests a competitive release hypothesis that Helicoverpa zea larval herbivory will 1) deter oviposition and increase leaving rates of the stink bugs, Euchistus servus and Nezara viridula and that 2) that these effects will be stronger for E. servus than for N. viridula. By spatially separa...

  14. Areawide suppression of European corn borer with Bt maize reaps savings to non-Bt maize growers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transgenic maize, engineered to express insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) has become one of the most widely adopted pest management technologies in U.S. agriculture. In 2009, Bt maize was planted on more than 22.2 million ha, comprising 63% of the U.S. crop. The te...

  15. Consequences for Protaphorura armata (Collembola: Onychiuridae) following exposure to genetically modified Bacillus thuringiensis (Bt) maize and non-Bt maize.

    PubMed

    Heckmann, Lars-Henrik; Griffiths, Bryan S; Caul, Sandra; Thompson, Jacqueline; Pusztai-Carey, Marianne; Moar, William J; Andersen, Mathias N; Krogh, Paul Henning

    2006-07-01

    Studies on the effect of genetically modified Bacillus thuringiensis (Bt) crops on true soil dwelling non-target arthropods are scarce. The objective of this study was to assess the influence of a 4-week exposure to two Bt maize varieties (Cry1Ab) Cascade and MEB307 on the collembolan Protaphorura armata. For comparison three non-Bt maize varieties, Rivaldo (isogenic to Cascade), Monumental (isogenic to MEB307) and DK242, and two control diets based on baker's yeast (uncontaminated and contaminated with Bt toxin Cry1Ab) were also tested. Due to a lower C:N ratio, individuals reared on yeast performed significantly better in all of the measured endpoints than those reared on maize. P. armata performed equally well when reared on two Bt and three non-Bt maize varieties. Although there were no negative effects of Bt maize in this experiment, we recommend future studies on Bt crops to focus on species interactions in long-term, multi-species experiments. PMID:16310913

  16. Antibiotics influence the toxicity of the delta endotoxins of Bacillus thuringiensis towards the cotton bollworm, Helicoverpa armigera

    PubMed Central

    2014-01-01

    Background The cotton bollworm, Helicoverpa armigera is one of the most important crop pests worldwide. It has developed high levels of resistance to synthetic insecticides, and hence, Bacillus thuringiensis (Bt) formulations are used as a safer pesticide and the Bt genes have been deployed in transgenic crops for controlling this pest. There is an apprehension that H. armigera might develop resistance to transgenic crops in future. Therefore, we studied the role of gut microbes by eliminating them with antibiotics in H. armigera larvae on the toxicity of Bt toxins against this pest. Results Commercial formulation of Bt (Biolep®) and the pure Cry1Ab and Cry1Ac toxin proteins were evaluated at ED50, LC50, and LC90 dosages against the H. armigera larvae with and without antibiotics (which removed the gut microbes). Lowest H. armigera larval mortality due to Bt formulation and the Bt toxins Cry1Ab and Cry1Ac was recorded in insects reared on diets with 250 and 500 μg ml−1 diet of each of the four antibiotics (gentamicin, penicillin, rifampicin, and streptomycin), while the highest larval mortality was recorded in insects reared on diets without the antibiotics. Mortality of H. armigera larvae fed on diets with Bt formulation and the δ-endotoxins Cry1Ab and Cry1Ac was inversely proportional to the concentration of antibiotics in the artificial diet. Nearly 30% reduction in larval mortality was observed in H. armigera larvae from F1 to F3 generation when the larvae were reared on diets without antibiotics (with gut microbes) and fed on 0.15% Bt or 12 μg Cry1Ab or Cry1Ac ml−1 diet, indicating development of resistance to Bt in the presence of gut microflora. However, there were no differences in larval mortality due to Bt, Cry1Ab or Cry1Ac across generations in insects when they were reared on diets with 250 μg of each antibiotic ml−1 diet (without gut microflora). Conclusions The results suggested that antibiotics which eliminated gut microflora

  17. Feeding cotton products to cattle.

    PubMed

    Rogers, Glenn M; Poore, Matthew H; Paschal, Joe C

    2002-07-01

    Despite the potential for gossypol toxicosis (particularly in pre-ruminants) and risk factors associated with impaired fertility in bulls, cottonseed products offer a safe alternative feed for cattle producers when fed at recommended levels. Beef producers seeking to lower production costs should consider using cotton byproducts in their feeding programs. If carefully incorporated, cotton byproduct feeds can reduce feed costs while maintaining or increasing the level of cattle performance. Cottonseed meal will remain a standard protein supplement for beef cattle throughout the country. Whole cottonseed has much potential for Southern producers near cotton gins if it is purchased in a timely fashion and fed according to recommendations. Cotton gin trash, cottonseed hulls, and cotton textile mill waste also have potential economic benefits, especially to producers located near cotton and cottonseed processing facilities. PMID:12235661

  18. Characterization of directly transformed weedy Brassica rapa and introgressed B. rapa with Bt cry1Ac and gfp genes.

    PubMed

    Moon, Hong S; Halfhill, Matthew D; Good, Laura L; Raymer, Paul L; Neal Stewart, C

    2007-07-01

    Crop to weed transgene flow, which could result in more competitive weed populations, is an agricultural biosafety concern. Crop Brassica napus to weedy Brassica rapa hybridization has been extensively characterized to better understand the transgene flow and its consequences. In this study, weedy accessions of B. rapa were transformed with Bacillus thuringiensis (Bt) cry1Ac- and green fluorescence protein (gfp)-coding transgenes using Agrobacterium to assess ecological performance of the wild biotype relative to introgressed hybrids in which the transgenic parent was the crop. Regenerated transgenic B. rapa events were characterized by progeny analysis, Bt protein enzyme-linked immunosorbent assay (ELISA), Southern blot analysis, and GFP expression assay. GFP expression level and Bt protein concentration were significantly different between independent transgenic B. rapa events. Similar reproductive productivity was observed in comparison between transgenic B. rapa events and B. rapa x B. napus introgressed hybrids in greenhouse and field experiments. In the greenhouse, Bt transgenic plants experienced significantly less herbivory damage from the diamondback moth (Plutella xylostella). No differences were found in the field experiment under ambient, low, herbivore pressure. Directly transformed transgenic B. rapa plants should be a helpful experimental control to better understand crop genetic load in introgressed transgenic weeds. PMID:17333014

  19. Stable Bacillus thuringiensis (Bt) toxin content in interspecific F1 and backcross populations of wild Brassica rapa after Bt gene transfer.

    PubMed

    Zhu, B; Lawrence, J R; Warwick, S I; Mason, P; Braun, L; Halfhill, M D; Stewart, C N

    2004-01-01

    Stable expression of a transgene may lead to increased fitness for wild plants after acquiring the transgene via crop-weed hybridization. Here, we investigate the stability of Bt toxin content in wild Brassica rapa acquiring the Bt gene from Bt Brassica napus. The Bt toxin content in nine Bt-expressing B. napus lines was 0.80-1.70 micro g/g leaf tissue throughout the growing season. These nine lines were crossed with three accessions of wild B. rapa and the Bt gene was successfully transferred to interspecific hybrids (F1) and successive backcross generations (BC1 to BC4). The Bt toxin level in F1 and BC progenies containing the Bt gene remained at 0.90-3.10 micro g/g leaf tissue. This study indicates that the Bt gene can persist and be stably expressed in wild B. rapa. PMID:14653804

  20. Cotton 2K-Management tools for irrigated cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of simulation models to manage crops was a concept introduced in the 1980’s. For example, the cotton simulation model known as GOSSYM was made available in 1989 and was used by both producers and consultants to manage cotton in real time. More recently, Dr. Avi Marani, Professor Emeritus, Sc...

  1. Cotton-Harvester-Flow Simulator for Testing Cotton Yield Monitor

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An experimental system was developed to simulate the pneumatic flow arrangement found in picker-type cotton harvesters. The simulation system was designed and constructed for testing a prototype cotton yield monitor developed at Mississippi State University. The simulation system was constructed to ...

  2. Cotton and Sustainability: Impacting Student Learning through Sustainable Cotton Summit

    ERIC Educational Resources Information Center

    Ha-Brookshire, Jung; Norum, Pamela

    2011-01-01

    Purpose: The purpose of this paper is to examine the effect of intensive extra-curricular learning opportunities on students' knowledge, skills, and attitudes regarding cotton and sustainability. Design/methodology/approach: A three-phase extra-curricular learning opportunity was designed to include a Sustainable Cotton Summit; pre-summit and…

  3. 7 CFR 27.43 - Validity of cotton class certificates.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Validity of cotton class certificates. 27.43 Section... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Cotton Class Certificates § 27.43 Validity of cotton class certificates. Each cotton class certificate for cotton...

  4. 7 CFR 27.43 - Validity of cotton class certificates.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Validity of cotton class certificates. 27.43 Section... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Cotton Class Certificates § 27.43 Validity of cotton class certificates. Each cotton class certificate for cotton...

  5. 7 CFR 27.43 - Validity of cotton class certificates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Validity of cotton class certificates. 27.43 Section... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Cotton Class Certificates § 27.43 Validity of cotton class certificates. Each cotton class certificate for cotton...

  6. 7 CFR 27.43 - Validity of cotton class certificates.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Validity of cotton class certificates. 27.43 Section... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Cotton Class Certificates § 27.43 Validity of cotton class certificates. Each cotton class certificate for cotton...

  7. 7 CFR 27.43 - Validity of cotton class certificates.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Validity of cotton class certificates. 27.43 Section... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Cotton Class Certificates § 27.43 Validity of cotton class certificates. Each cotton class certificate for cotton...

  8. Harmonia axyridis (Coleoptera: Coccinellidae) Exhibits No Preference between Bt and Non-Bt Maize Fed Spodoptera frugiperda (Lepidoptera: Noctuidae)

    PubMed Central

    Dutra, Carla C.; Koch, Robert L.; Burkness, Eric C.; Meissle, Michael; Romeis, Joerg; Hutchison, William D.; Fernandes, Marcos G.

    2012-01-01

    A recent shift in managing insect resistance to genetically engineered (GE) maize consists of mixing non-GE seed with GE seed known as “refuge in a bag”, which increases the likelihood of predators encountering both prey fed Bt and prey fed non-Bt maize. We therefore conducted laboratory choice-test feeding studies to determine if a predator, Harmonia axyridis, shows any preference between prey fed Bt and non-Bt maize leaves. The prey species was Spodoptera frugiperda, which were fed Bt maize (MON-810), expressing the single Cry1Ab protein, or non-Bt maize. The predators were third instar larvae and female adults of H. axyridis. Individual predators were offered Bt and non-Bt fed prey larvae that had fed for 24, 48 or 72 h. Ten and 15 larvae of each prey type were offered to third instar and adult predators, respectively. Observations of arenas were conducted at 1, 2, 3, 6, 15 and 24 h after the start of the experiment to determine the number and type of prey eaten by each individual predator. Prey larvae that fed on non-Bt leaves were significantly larger than larvae fed Bt leaves. Both predator stages had eaten nearly all the prey by the end of the experiment. However, in all combinations of predator stage and prey age, the number of each prey type consumed did not differ significantly. ELISA measurements confirmed the presence of Cry1Ab in leaf tissue (23–33 µg/g dry weight) and S. frugiperda (2.1–2.2 µg/g), while mean concentrations in H. axyridis were very low (0.01–0.2 µg/g). These results confirm the predatory status of H. axyridis on S. frugiperda and that both H. axyridis adults and larvae show no preference between prey types. The lack of preference between Bt-fed and non-Bt-fed prey should act in favor of insect resistance management strategies using mixtures of GE and non-GE maize seed. PMID:23024772

  9. CottonGen: a genomics, genetics and breeding database for cotton research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    CottonGen (http://www.cottongen.org) is a curated and integrated web-based relational database providing access to publicly available genomic, genetic and breeding data for cotton. CottonGen supercedes CottonDB and the Cotton Marker Database, with enhanced tools for easier data sharing, mining, vis...

  10. Exploring biomedical applications of cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of cotton as a biomaterial for design of improved wound dressings, and other non-implantable medical textiles will be considered. The research and development of cotton-based wound dressings, which possess a mechanism-based mode of action, has entered a new level of understanding in recent ...

  11. COTTON FIBER CHEMISTRY AND TECHNOLOGY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Annual cotton production exceeds 25 million metric tons and accounts for more than 40 percent of the textile fiber consumed worldwide. A key textile fiber for over 5000 years, this complex carbohydrate is also one of the leading crops to benefit from genetic engineering. Cotton Fiber Chemistry and...

  12. Natural cotton and flax fibers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The origins of cotton (Gossypium barbadense L. or Gossypium hirsutum L.) and flax (Linum usitatissimum L.) are somewhat of a mystery. Cotton currently maintains a 65 % share of the consumer textile market while flax maintains about 2-3 %. Cellulose is a major component in these crops ranging from ...

  13. Exploring biomedical ppplications of cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of cotton as a biomaterial for design of improved wound dressings, and other non-implantable medical textiles will be considered. The research and development of cotton-based wound dressings, which possess a mechanism-based mode of action, has entered a new level of understanding in recent y...

  14. The Spindle Type Cotton Harvester

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The spindle type cotton picker was commercialized during the mid 1900’s and is currently produced by two US agricultural equipment manufacturers, John Deere and CaseIH. Picking is the predominate machine harvest method used throughout the US and world. Harvesting efficiency of a spindle type cotton ...

  15. Microwave drying of seed cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A small lab dryer was designed for use in drying seed cotton with components of a microwave generator mounted thereon. The magnetron emitted radiation directly into the seed cotton and a fan directed air cross-flow to the radiation direction. The microwave components were a 1.1 kW magnetron, trans...

  16. No Evidence that Bt Genes and their Products Influence the Susceptibility of Corn Residue to Decomposition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Continuing speculation concerning slower residue decomposition for Bt corn (Zea mays L.) hybrids compared to non-Bt corn hybrids has prompted a search for potential explanations. To determine if the genetics (Bt or non-Bt) of growing or senescing corn plants may influence the decomposition of co-ex...

  17. Effects of pink bollworm resistance to Bt on phenoloxidase activity and susceptibility to entomopathogenic nematodes.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Widespread planting of crops genetically engineered to produce insecticidal toxins from the bacterium Bacillus thuringiensis (Bt) imposes selection on many key agricultural pests to evolve resistance to Bt. Fitness costs of Bt resistance can slow the evolution of Bt resistance. We examined effects...

  18. 7 CFR 1205.13 - Upland cotton.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Upland cotton. 1205.13 Section 1205.13 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Procedures for Conduct of Sign-up Period Definitions § 1205.13 Upland cotton. The term Upland cotton...

  19. 7 CFR 1205.12 - Cotton.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Cotton. 1205.12 Section 1205.12 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Procedures for Conduct of Sign-up Period Definitions § 1205.12 Cotton. The term cotton means all...

  20. 7 CFR 1205.12 - Cotton.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Cotton. 1205.12 Section 1205.12 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Procedures for Conduct of Sign-up Period Definitions § 1205.12 Cotton. The term cotton means all...

  1. 7 CFR 1205.13 - Upland cotton.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Upland cotton. 1205.13 Section 1205.13 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Procedures for Conduct of Sign-up Period Definitions § 1205.13 Upland cotton. The term Upland cotton...

  2. 7 CFR 1205.13 - Upland cotton.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Upland cotton. 1205.13 Section 1205.13 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Procedures for Conduct of Sign-up Period Definitions § 1205.13 Upland cotton. The term Upland cotton...

  3. 7 CFR 1205.12 - Cotton.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Cotton. 1205.12 Section 1205.12 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Procedures for Conduct of Sign-up Period Definitions § 1205.12 Cotton. The term cotton means all...

  4. 7 CFR 1205.12 - Cotton.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Cotton. 1205.12 Section 1205.12 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Procedures for Conduct of Sign-up Period Definitions § 1205.12 Cotton. The term cotton means all...

  5. 7 CFR 1205.13 - Upland cotton.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Upland cotton. 1205.13 Section 1205.13 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Procedures for Conduct of Sign-up Period Definitions § 1205.13 Upland cotton. The term Upland cotton...

  6. 7 CFR 1205.12 - Cotton.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Cotton. 1205.12 Section 1205.12 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Procedures for Conduct of Sign-up Period Definitions § 1205.12 Cotton. The term cotton means all...

  7. 7 CFR 1205.13 - Upland cotton.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Upland cotton. 1205.13 Section 1205.13 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Procedures for Conduct of Sign-up Period Definitions § 1205.13 Upland cotton. The term Upland cotton...

  8. COMMERCIAL COTTON VARIETY SPINNING STUDY QUALITY INDICES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The USDA-ARS Cotton Quality Research Station has completed a comprehensive study studying the relationship of cotton fiber properties to the quality of spun yarn. Cotton was spun into yarn at the CQRS laboratory by each of three spinning methods (ring, vortex and rotor spinning). Cotton in this st...

  9. Cotton Quality Indices of Spun Yarn

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton was spun into yarn at the Cotton Quality Research Station by each of three spinning methods (ring, vortex, and open end spinning) to determine if a relationship exits between cotton fiber properties and the quality of spun yarn. Cotton was grown and harvested in 2001-2005 from three of the l...

  10. Bt brinjal in India: a long way to go.

    PubMed

    Kumar, Sandeep; Misra, Amita; Verma, Alok Kumar; Roy, Ruchi; Tripathi, Anurag; Ansari, Kausar M; Das, Mukul; Dwivedi, Premendra D

    2011-01-01

    Brinjal occupies the major proportion amongst all vegetable crops in India and is vulnerable to many diseases caused by insect-pests, fungus, bacteria and virus. Brinjal production is extensively affected by the insect brinjal fruit and shoot borer. Use of conventional chemical pesticides not only damage environment including the biotic and abiotic components but, also affect human health. Bt Brinjal was developed to combat brinjal fruit and shoot borer that has an advantage minimizing use of chemical pesticides. Extensive biosafety investigations, nutritional studies, substantial equivalence studies, relative toxicity and allergenicity assessment using animal models like Sprague Dawley rats, Brown Norway rats, rabbit, fish, chicken, goats, etc. revealed no significant differences between genetically modified brinjal and its native counterpart. Bt brinjal could effectively control the target pest and was found to be safe for environment and human health. In spite of all the scientific studies, release of Bt Brinjal has been put under moratorium. Indian government has constituted an expert committee to address this issue. In this review we have tried to explore the facts related to Bt Brinjal including its production, use of Bt toxin, use of chemical pesticides in controlling the FSB in native brinjal, along with perspective of public opinion and government initiatives. Key words: Bt Brinjal, agriculture, insecticides, GM foods, agrobacterium, transgenic crops. PMID:21865863

  11. Spodoptera frugiperda (J.E. Smith) with field-evolved resistance to Bt maize are susceptible to Bt pesticides.

    PubMed

    Jakka, S R K; Knight, V R; Jurat-Fuentes, J L

    2014-10-01

    Field-evolved resistance to maize event TC1507 expressing the Cry1Fa toxin from Bacillus thuringiensis (Bt) was detected in populations of Spodoptera frugiperda from Puerto Rico. We tested for cross-resistance to purified Cry1A toxins and commercial Bt pesticides in susceptible (Benzon) and TC1507-resistant (456) strains of S. frugiperda. Larvae from the 456 strain exhibited cross-resistance to Cry1Ab and Cry1Ac toxins, while no differences in susceptibility to XenTari WG and DiPel ES pesticides were detected. These data support cross-resistance to toxins that share binding sites with Cry1Fa and no cross-resistance to Bt pesticides in S. frugiperda with field-evolved resistance to Bt maize. PMID:25218399

  12. Soil microbial communities associated with Bt and non-Bt corn in three soils.

    PubMed

    Blackwood, Christopher B; Buyer, Jeffrey S

    2004-01-01

    The effects of expression of Cry endotoxin by Bt corn (transgenic corn engineered to express Bacillus thuringiensis toxin) on soil microbial community structure were assessed in a growth chamber experiment. Two lines of transgenic corn expressing different Cry endotoxins were compared with their respective non-transgenic isolines in three soil types with differing textures. Phospholipid fatty acid (PLFA) profiles from bulk soil and community-level physiological profiles (CLPP) from the rhizosphere community were used to assess community structure. Differences in PLFA profiles due to soil type were significant, accounting for 73% of the total variability in the dataset. Differences in bacterial and fungal CLPP profiles due to soil type were statistically significant, but probably not biologically important, accounting for 6.3 and 3.8% of the total variability, respectively. Neither expression of Cry endotoxin nor corn line had a significant effect on microbial profiles, except in the high-clay soil where both factors significantly affected bacterial CLPP profiles (accounting for 6.6 and 6.1% of the variability in that soil, respectively). Expression of Cry endotoxin also significantly reduced the presence of eukaryotic PLFA biomarker in bulk soils, although it is unclear which groups of eukaryotes were affected. We conclude that the effects of transgenic Bt corn in this short-term experiment are small, and longer-term investigations are necessary. PMID:15224917

  13. Occurrence and field densities of Coleoptera in the maize herb layer: implications for Environmental Risk Assessment of genetically modified Bt-maize.

    PubMed

    Rauschen, Stefan; Schaarschmidt, Frank; Gathmann, Achim

    2010-10-01

    Beetles (Coleoptera) are a diverse and ecologically important group of insects in agricultural systems. The Environmental Risk Assessment (ERA) of genetically modified Bt-crop varieties with insect resistances thus needs to consider and assess the potential negative impacts on non-target organisms belonging to this group. We analysed data gathered during 6 years of field-release experiments on the impact of two genetically modified Bt-maize varieties (Ostrinia-resistant MON810 and Diabrotica-resistant MON88017) on the occurrence and field densities of Coleoptera, especially the two families Coccinellidae and Chrysomelidae. Based on a statistical analysis aimed at establishing whether Bt-maize varieties are equivalent to their near-isogenic counterparts, we discuss the limitations of using field experiments to assess the effects of Bt-maize on these two beetle families. The densities of most of the beetle families recorded in the herb layer were very low in all growing seasons. Coccinellidae and Chrysomelidae were comparatively abundant and diverse, but still low in numbers. Based on their role as biological control agents, Coccinellidae should be a focus in the ERA of Bt-plants, but given the large natural variability in ladybird densities in the field, most questions need to be addressed in low-tier laboratory tests. Chrysomelidae should play a negligible role in the ERA of Bt-plants, since they occur on-crop as secondary pests only. Species occurring off-crop, however, can be addressed in a similar fashion as non-target Lepidoptera in Cry1Ab expressing Bt-maize. PMID:20012775

  14. Bt rice does not disrupt the host-searching behavior of the parasitoid Cotesia chilonis

    PubMed Central

    Liu, Qingsong; Romeis, Jörg; Yu, Huilin; Zhang, Yongjun; Li, Yunhe; Peng, Yufa

    2015-01-01

    We determined whether plant volatiles help explain why Cotesia chilonis (a parasitoid of the target pest Chilo suppressalis) is less abundant in Bt than in non-Bt rice fields. Olfactometer studies revealed that C. chilonis females responded similarly to undamaged Bt and non-Bt rice plants. Parasitoids preferred rice plants damaged by 3rd-instar larvae of C. suppressalis, but did not differentiate between caterpillar-infested Bt and non-Bt plants. According to GC-MS analyses of rice plant volatiles, undamaged Bt and non-Bt rice plants emitted the same number of volatile compounds and there were no significant differences in the quantity of each volatile compound between the treatments. When plants were infested with and damaged by C. suppressalis larvae, both Bt and non-Bt rice plants emitted higher numbers and larger amounts of volatile compounds than undamaged plants, but there were no significant differences between Bt and non-Bt plants. These results demonstrate that the volatile-mediated interactions of rice plants with the parasitoid C. chilonis were not disrupted by the genetic engineering of the plants. We infer that parasitoid numbers are lower in Bt than in non-Bt fields because damage and volatile induction by C. suppressalis larvae are greatly reduced in Bt fields. PMID:26470012

  15. Modeling the impact of alternative hosts on Helicoverpa zea adaptation to bollgard cotton.

    PubMed

    Gustafson, David I; Head, Graham P; Caprio, Michael A

    2006-12-01

    For highly polyphagous cotton, Gossypium hirsutum L., pests such as Helicoverpa zea (Boddie), a substantial portion of the larval population develops on noncotton alternative hosts. These noncotton hosts potentially provide a natural refuge for H. zea, thereby slowing the evolution of resistance to the Bacillus thuringiensis Berliner (Bt)-derived Cry1Ac protein present in Bollgard cotton. Here, we demonstrate how the measured contribution of such alternative hosts can be included in estimating the "effective refuge" present for H. zea and in modeling resistance evolution in this species. A single-gene, two-compartment model was used in which one compartment represented corn, Zea mays L., and cotton that express the Cry1Ac protein or similar proteins, and the other compartment was the effective refuge, made up of a weighted average of non-Bt cotton and noncotton hosts. The effective refuge was estimated for each of six generations of H. zea based upon available data on larval population densities on different hosts and cropping patterns. Model runs were performed for regions centered on three states: Georgia, Mississippi, and North Carolina. Three sets of fitness cost assumptions for the putative resistance gene were used: none, low, and moderate, with either recessive or additive inheritance for resistance and fitness costs. For Georgia and North Carolina, resistance was predicted to take >30 yr to evolve except in the absence of fitness costs. For Mississippi, results were sensitive to fitness costs: >30 yr with moderate costs, 7-14 yr with low costs, and 6-10 yr without such costs. PMID:17195681

  16. Vip3A Resistance Alleles Exist at High Levels in Australian Targets before Release of Cotton Expressing This Toxin

    PubMed Central

    Mahon, Rod J.; Downes, Sharon J.; James, Bill

    2012-01-01

    Crops engineered to produce insecticidal crystal (Cry) proteins from the soil bacterium Bacillus thuringiensis (Bt) have revolutionised pest control in agriculture. However field-level resistance to Bt has developed in some targets. Utilising novel vegetative insecticidal proteins (Vips), also derived from Bt but genetically distinct from Cry toxins, is a possible solution that biotechnical companies intend to employ. Using data collected over two seasons we determined that, before deployment of Vip-expressing plants in Australia, resistance alleles exist in key targets as polymorphisms at frequencies of 0.027 (n = 273 lines, 95% CI = 0.019–0.038) in H. armigera and 0.008 (n = 248 lines, 0.004–0.015) in H. punctigera. These frequencies are above mutation rates normally encountered. Homozygous resistant neonates survived doses of Vip3A higher than those estimated in field-grown plants. Fortunately the resistance is largely, if not completely, recessive and does not confer resistance to the Bt toxins Cry1Ac or Cry2Ab already deployed in cotton crops. These later characteristics are favourable for resistance management; however the robustness of Vip3A inclusive varieties will depend on resistance frequencies to the Cry toxins when it is released (anticipated 2016) and the efficacy of Vip3A throughout the season. It is appropriate to pre-emptively screen key targets of Bt crops elsewhere, especially those such as H. zea in the USA, which is not only closely related to H. armigera but also will be exposed to Vip in several varieties of cotton and corn. PMID:22761737

  17. [Change of Bt protein in soil after growing Bt corns and returning corn straws to soil and its effects on soil nutrients].

    PubMed

    Zeng, Ping; Feng, Yuan-Jiao; Zhang, Wan-Chun; Zhang, Yan-Fei; Dong, Wen-Chao; Wang, Jian-Wu

    2014-07-01

    The spatiotemporal dynamics of Bt protein in soil and the change of soil nutrients in rhizosphere soil, root surface soil and soils at 0-20, 20-40 and 40-60 cm were measured in greenhouse experiments. Two Bt corns, 5422Bt1 and 5422CBCL, and their near isogenic non-Bt variety 5422 were grown for 90 days and the crop residues were retained to soil. Results showed that 1.59 and 2.78 ng x g(-1) Bt protein were detected in the rhizosphere soil with Bt corns 5422Bt1 and 5422CBCL immediately after harvest. However, there were only trace amounts of Bt protein (< 0.5 ng x g(-1)) were detected in root surface soil after 90 days and in bulk soil in the two Bt corn treatments after 30, 60 and 90 days. When corn residues returned to soil, Bt protein declined rapidly within 3 days and only trace amounts of Bt protein were measured after 7 days. There were no sig- nificant differences in organic matter, available nutrient (alkaline hydrolytic N, available P, available K) or total nutrient (total N, total P, total K) in root surface soils and soils at 0-20 cm, 20-40 cm and 40-60 cm among the Bt and non-Bt corns after 90 days. Sixty days after returning crop residues of 5422Btl to soil, the contents of organic matter and total N increased and the content of available K reduced significantly in the 0-20 cm soil depth. There were no significant differences in any other parameter at the 0-20 cm depth, neither for any parameter in the 20-40 cm and 40-60 cm soil depths compared to those in the non-Bt corn 5422 treatment. There were no significant differences in soil nutrient contents in Bt corn 5422CBCL treatment compared to those in non-Bt corn 5422 treatment except that available phosphorus content was reduced in root surface soils, and total P content increased at the 0-20 cm soil depth after 90 days. When crop residues of Bt corn 5422 CBCL were returned to soil, only available P content in the 0-20 cm soil layer was evidently higher compared to the soil receiving crop residues of

  18. A cotton dust study unmasked.

    PubMed

    Levine, C

    1984-08-01

    The Dan River Company, citing news reports damaging to its image, has abandoned a proposed study to test a theory that byssinosis (brown lung disease) is caused by a bacterium growing in cotton rather than by inhalation of cotton dust. With state approval to exceed federal standards on cotton dust exposure, the company submitted the study to the Occupational Safety and Health Administration as a "variance," not as human subjects research. Levine contends that the proposal violated all major criteria of the federal regulations for protection of research subjects--scientific objectivity, balanced risks and benefits, and voluntary and informed consent. PMID:6480334

  19. Preprocessing cotton to prevent byssinosis

    PubMed Central

    Merchant, James A.; Lumsden, John C.; Kilburn, Kaye H.; Germino, Victor H.; Hamilton, John D.; Lynn, William S.; Byrd, H.; Baucom, D.

    1973-01-01

    Merchant, J. A., Lumsden, J. C., Kilburn, K. H., Germino, V. H., Hamilton, J. D., Lynn, W. S., Byrd, H., and Baucom, D. (1973).British Journal of Industrial Medicine,30, 237-247. Preprocessing cotton to prevent byssinosis. A fundamental approach of cleaning or deactivating cotton prior to manufacturing has long been advocated to prevent byssinosis, but no trial had been conducted to test the feasibility of such an approach. In the study described, it was possible to be directed by both biological observations and the results of manufacturing trials. An exposure chamber was built in a cotton textile mill which had been previously studied as part of a large cross-sectional survey. The chamber was provided with an independent air conditioning system and a carding machine which served as a dust generator. Sixteen subjects, who had shown reductions in expiratory flow rate with exposure to cotton dust, were chosen to form a panel for exposure to raw cottons and cottons which had been preprocessed by heating, washing, and steaming. Indicators of effects were symptoms of chest tightness and/or dyspnoea, change in FEV1·0, and fine dust levels over 6 hours of exposure. Exposure of the panel to no cotton dust resulted in no change in FEV1·0 and served as the control for subsequent trials. Exposure to strict middling cotton resulted in a byssinosis symptom prevalence of 22%, a significant decrement in FEV1·0 of 2·9%, and a fine dust level of 0·26 mg/m3. Exposure to strict low middling cotton resulted in a byssinosis symptom prevalence of 79%, a decrement in FEV1·0 of 8·5%, and a fine dust level of 0·89 mg/m3. Oven heating strict low middling cotton resulted in a byssinosis symptom prevalence of 56% and a relatively greater drop in FEV1·0 of 8·3% for 0·48 mg/m3 of fine dust. Washing the strict low grade cotton eliminated detectable biological effects with a symptom prevalence of 8%, an increase of 1·4% in FEV1·, and a dust level of 0·16 mg/m3, but the cotton

  20. Field and laboratory evaluations of transgenic cottons expressing one or two Bacillus thuringiensis var. kurstaki Berliner proteins for management of noctuid (Lepidoptera) pests.

    PubMed

    Chitkowski, R L; Turnipseed, S G; Sullivan, M J; Bridges, W C

    2003-06-01

    Field studies were conducted from 1999 to 2001 to evaluate the efficacy of the transgenic cotton, Gossypium hirsutum (L.), genotype, Bollgard II (Monsanto 15985), which expresses two Bacillus thuringiensis Berliner (Bt) proteins (Cry1Ac + Cry2Ab) that are active against lepidopterous pests. Bollgard II was compared with Bollgard (DP50B), which expresses only one Bt protein (Cry1Ac), and, in all tests, the conventional variety, DP50, was used as a non-Bt control. Larval populations of the bollworm, Helicoverpa zea (Boddie), and the soybean looper, Pseudoplusia includens (Walker), were significantly lower in Bollgard II than in Bollgard and conventional cotton, and the proportion of fruit damaged by H. zea was also lower. Fall armyworm, Spodoptera frugiperda (J. E. Smith), populations were lower in Bollgard II than in Bollgard, although not significantly. Field tests were supplemented with laboratory bioassays in 2001 to compare mortality of S. frugiperda, and beet armyworms, Spodoptera exigua (Hübner), feeding on these genotypes. Mortality of both species was significantly greater on Bollgard II plant material than on either Bollgard or conventional cotton. This study demonstrated that the dual-toxin Bollgard II genotype is highly effective against lepidopterous pests that are not adequately controlled by the current single-toxin Bollgard varieties. If toxin expression in future Bollgard II varieties remains consistent with that of Monsanto 15985, supplemental insecticides will be reduced, and may be eliminated for lepidopterous pests in South Carolina. PMID:12852613

  1. Transgenic Bacillus thuringiensis (Bt) rice is safer to aquatic ecosystems than its non-transgenic counterpart.

    PubMed

    Li, Guangsheng; Wang, Yongmo; Liu, Biao; Zhang, Guoan

    2014-01-01

    Rice lines genetically modified with the crystal toxin genes from Bacillus thuringiensis (Bt) have experienced rapid development, with biosafety certificates for two Bt rice lines issued in 2009. There has still been no commercial release of these lines yet due to public concerns about human health and environmental risks. Some studies confirmed that Bt rice was as safe as conventional rice to non-target organisms when pesticides were not applied, however, pesticides are still required in Bt rice to control non-lepidopteran pests. In this study, we assessed the environmental effects of two Bt rice lines expressing either the cry1Ab/1Ac or cry2A genes, respectively, by using zooplanktons as indicator species under normal field management practices using pesticides when required. In the whole rice growing season, non-Bt rice was sprayed 5 times while Bt rice was sprayed 2 times, which ensured both rice achieved a normal yield. Field investigations showed that rice type (Bt and non-Bt) significantly influenced zooplankton abundance and diversity, which were up to 95% and 80% lower in non-Bt rice fields than Bt rice fields. Laboratory rearing showed that water from non-Bt rice fields was significantly less suitable for the survival and reproduction of Daphnia magna and Paramecium caudatum in comparison with water from Bt rice fields. Higher pesticide residues were detected in the water from non-Bt than Bt rice fields, accounting for the bad performance of zooplankton in non-Bt field water. Our results demonstrate that Bt rice is safer to aquatic ecosystems than non-Bt rice, and its commercialization will be beneficial for biodiversity restoration in rice-based ecosystems. PMID:25105299

  2. Transgenic Bacillus thuringiensis (Bt) Rice Is Safer to Aquatic Ecosystems than Its Non-Transgenic Counterpart

    PubMed Central

    Li, Guangsheng; Wang, Yongmo; Liu, Biao; Zhang, Guoan

    2014-01-01

    Rice lines genetically modified with the crystal toxin genes from Bacillus thuringiensis (Bt) have experienced rapid development, with biosafety certificates for two Bt rice lines issued in 2009. There has still been no commercial release of these lines yet due to public concerns about human health and environmental risks. Some studies confirmed that Bt rice was as safe as conventional rice to non-target organisms when pesticides were not applied, however, pesticides are still required in Bt rice to control non-lepidopteran pests. In this study, we assessed the environmental effects of two Bt rice lines expressing either the cry1Ab/1Ac or cry2A genes, respectively, by using zooplanktons as indicator species under normal field management practices using pesticides when required. In the whole rice growing season, non-Bt rice was sprayed 5 times while Bt rice was sprayed 2 times, which ensured both rice achieved a normal yield. Field investigations showed that rice type (Bt and non-Bt) significantly influenced zooplankton abundance and diversity, which were up to 95% and 80% lower in non-Bt rice fields than Bt rice fields. Laboratory rearing showed that water from non-Bt rice fields was significantly less suitable for the survival and reproduction of Daphnia magna and Paramecium caudatum in comparison with water from Bt rice fields. Higher pesticide residues were detected in the water from non-Bt than Bt rice fields, accounting for the bad performance of zooplankton in non-Bt field water. Our results demonstrate that Bt rice is safer to aquatic ecosystems than non-Bt rice, and its commercialization will be beneficial for biodiversity restoration in rice-based ecosystems. PMID:25105299

  3. Cross-resistance to toxins used in pyramided Bt crops and resistance to Bt sprays in Helicoverpa zea.

    PubMed

    Welch, Kara L; Unnithan, Gopalan C; Degain, Ben A; Wei, Jizhen; Zhang, Jie; Li, Xianchun; Tabashnik, Bruce E; Carrière, Yves

    2015-11-01

    To delay evolution of resistance by insect pests, farmers are rapidly increasing their use of transgenic crops producing two or more Bacillus thuringiensis (Bt) toxins that kill the same pest. A key condition favoring durability of these "pyramided" crops is the absence of cross-resistance between toxins. Here we evaluated cross-resistance in the major lepidopteran pest Helicoverpa zea (Boddie) to Bt toxins used in pyramids. In the laboratory, we selected a strain of this pest with Bt toxin Cry1Ac followed by selection with MVP II, a formulation containing a hybrid protoxin that is identical to Cry1Ac in the active portion of the toxin and 98.5% identical overall. We calculated the resistance ratio as the EC50 (concentration causing mortality or failure to develop beyond the first instar of 50% of larvae) for the laboratory-selected strain divided by the EC50 for its field-derived parent strain that was not selected in the laboratory. The resistance ratio was 20.0-33.9 (mean=27.0) for MVP II, 57.0 for Cry1Ac, 51.3 for Cry1A.105, 22.4 for Cry1Ab, 3.3 for Cry2Ab, 1.8 for Cry1Fa, and 1.6 for Vip3Aa. Resistance ratios were 2.9 for DiPel ES and 2.0 for Agree VG, which are commercial Bt spray formulations containing Cry1Ac, other Bt toxins, and Bt spores. By the conservative criterion of non-overlap of 95% fiducial limits, the EC50 was significantly higher for the selected strain than its parent strain for MVP II, Cry1Ac, Cry1A.105, Cry1Ab, Cry2Ab and DiPel ES. For Cry1Fa, Vip3Aa, and Agree VG, significantly lower susceptibility to a high concentration indicated low cross-resistance. The resistance ratio for toxins other than Cry1Ac was associated with their amino acid sequence similarity to Cry1Ac in domain II. Resistance to Cry1Ac and the observed cross-resistance to other Bt toxins could accelerate evolution of H. zea resistance to currently registered Bt sprays and pyramided Bt crops. PMID:26458274

  4. 7 CFR 1205.341 - Certification of cotton producer organization.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Certification of cotton producer organization. 1205... COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Certification of Cotton Producer Organization § 1205.341 Certification of cotton producer organization. Any cotton producer organization...

  5. 7 CFR 27.44 - Invalidity of cotton class certificates.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Invalidity of cotton class certificates. 27.44 Section... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Cotton Class Certificates § 27.44 Invalidity of cotton class certificates. Any cotton class certificate shall become...

  6. 7 CFR 1205.341 - Certification of cotton producer organization.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Certification of cotton producer organization. 1205... COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Certification of Cotton Producer Organization § 1205.341 Certification of cotton producer organization. Any cotton producer organization...

  7. 7 CFR 27.73 - Supervision of transfers of cotton.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Supervision of transfers of cotton. 27.73 Section 27... REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Transfers of Cotton § 27.73 Supervision of transfers of cotton. Whenever the owner of any cotton inspected and sampled for...

  8. 7 CFR 1205.341 - Certification of cotton producer organization.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Certification of cotton producer organization. 1205... COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Certification of Cotton Producer Organization § 1205.341 Certification of cotton producer organization. Any cotton producer organization...

  9. 7 CFR 28.471 - Below Leaf Grade Cotton.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Below Leaf Grade Cotton. 28.471 Section 28.471... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Below Leaf Grade Cotton § 28.471 Below Leaf Grade Cotton. Below leaf grade cotton is American Upland cotton which is lower in leaf grade than...

  10. 7 CFR 27.73 - Supervision of transfers of cotton.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Supervision of transfers of cotton. 27.73 Section 27... REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Transfers of Cotton § 27.73 Supervision of transfers of cotton. Whenever the owner of any cotton inspected and sampled for...

  11. 7 CFR 1205.341 - Certification of cotton producer organization.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Certification of cotton producer organization. 1205... COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Certification of Cotton Producer Organization § 1205.341 Certification of cotton producer organization. Any cotton producer organization...

  12. 7 CFR 28.471 - Below Leaf Grade Cotton.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Below Leaf Grade Cotton. 28.471 Section 28.471... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Below Leaf Grade Cotton § 28.471 Below Leaf Grade Cotton. Below leaf grade cotton is American Upland cotton which is lower in leaf grade than...

  13. 7 CFR 27.44 - Invalidity of cotton class certificates.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Invalidity of cotton class certificates. 27.44 Section... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Cotton Class Certificates § 27.44 Invalidity of cotton class certificates. Any cotton class certificate shall become...

  14. 7 CFR 1205.341 - Certification of cotton producer organization.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Certification of cotton producer organization. 1205... COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Certification of Cotton Producer Organization § 1205.341 Certification of cotton producer organization. Any cotton producer organization...

  15. 7 CFR 27.44 - Invalidity of cotton class certificates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Invalidity of cotton class certificates. 27.44 Section... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Cotton Class Certificates § 27.44 Invalidity of cotton class certificates. Any cotton class certificate shall become...

  16. 7 CFR 27.44 - Invalidity of cotton class certificates.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Invalidity of cotton class certificates. 27.44 Section... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Cotton Class Certificates § 27.44 Invalidity of cotton class certificates. Any cotton class certificate shall become...

  17. 7 CFR 28.471 - Below Leaf Grade Cotton.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Below Leaf Grade Cotton. 28.471 Section 28.471... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Below Leaf Grade Cotton § 28.471 Below Leaf Grade Cotton. Below leaf grade cotton is American Upland cotton which is lower in leaf grade than...

  18. 7 CFR 27.73 - Supervision of transfers of cotton.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Supervision of transfers of cotton. 27.73 Section 27... REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Transfers of Cotton § 27.73 Supervision of transfers of cotton. Whenever the owner of any cotton inspected and sampled for...

  19. 7 CFR 28.471 - Below Leaf Grade Cotton.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Below Leaf Grade Cotton. 28.471 Section 28.471... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Below Leaf Grade Cotton § 28.471 Below Leaf Grade Cotton. Below leaf grade cotton is American Upland cotton which is lower in leaf grade than...

  20. 7 CFR 27.44 - Invalidity of cotton class certificates.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Invalidity of cotton class certificates. 27.44 Section... CONTAINER REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Cotton Class Certificates § 27.44 Invalidity of cotton class certificates. Any cotton class certificate shall become...

  1. 7 CFR 28.471 - Below Leaf Grade Cotton.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Below Leaf Grade Cotton. 28.471 Section 28.471... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Below Leaf Grade Cotton § 28.471 Below Leaf Grade Cotton. Below leaf grade cotton is American Upland cotton which is lower in leaf grade than...

  2. Market Forces and Technological Substitutes Cause Fluctuations in the Value of Bat Pest-Control Services for Cotton

    PubMed Central

    López-Hoffman, Laura; Wiederholt, Ruscena; Sansone, Chris; Bagstad, Kenneth J.; Cryan, Paul; Diffendorfer, Jay E.; Goldstein, Joshua; LaSharr, Kelsie; Loomis, John; McCracken, Gary; Medellín, Rodrigo A.; Russell, Amy; Semmens, Darius

    2014-01-01

    Critics of the market-based, ecosystem services approach to biodiversity conservation worry that volatile market conditions and technological substitutes will diminish the value of ecosystem services and obviate the “economic benefits” arguments for conservation. To explore the effects of market forces and substitutes on service values, we assessed how the value of the pest-control services provided by Mexican free-tailed bats (Tadarida brasiliensis mexicana) to cotton production in the southwestern U.S. has changed over time. We calculated service values each year from 1990 through 2008 by estimating the value of avoided crop damage and the reduced social and private costs of insecticide use in the presence of bats. Over this period, the ecosystem service value declined by 79% ($19.09 million U.S. dollars) due to the introduction and widespread adoption of Bt (Bacillus thuringiensis) cotton transgenically modified to express its own pesticide, falling global cotton prices and the reduction in the number of hectares in the U.S. planted with cotton. Our results demonstrate that fluctuations in market conditions can cause temporal variation in ecosystem service values even when ecosystem function – in this case bat population numbers – is held constant. Evidence is accumulating, however, of the evolution of pest resistance to Bt cotton, suggesting that the value of bat pest-control services may increase again. This gives rise to an economic option value argument for conserving Mexican free-tailed bat populations. We anticipate that these results will spur discussion about the role of ecosystem services in biodiversity conservation in general, and bat conservation in particular. PMID:24498400

  3. Market forces and technological substitutes cause fluctuations in the value of bat pest-control services for cotton

    USGS Publications Warehouse

    López-Hoffman, Laura; Wiederholt, Ruscena; Sansone, Chris; Bagstad, Kenneth J.; Cryan, Paul M.; Diffendorfer, James E.; Goldstein, Joshua; LaSharr, Kelsie; Loomis, John; McCracken, Gary; Medellin, Rodrigo A.; Russell, Amy; Semmens, Darius J.

    2014-01-01

    Critics of the market-based, ecosystem services approach to biodiversity conservation worry that volatile market conditions and technological substitutes will diminish the value of ecosystem services and obviate the “economic benefits” arguments for conservation. To explore the effects of market forces and substitutes on service values, we assessed how the value of the pest-control services provided by Mexican free-tailed bats (Tadarida brasiliensis mexicana) to cotton production in the southwestern U.S. has changed over time. We calculated service values each year from 1990 through 2008 by estimating the value of avoided crop damage and the reduced social and private costs of insecticide use in the presence of bats. Over this period, the ecosystem service value declined by 79% ($19.09 million U.S. dollars) due to the introduction and widespread adoption of Bt (Bacillus thuringiensis) cotton transgenically modified to express its own pesticide, falling global cotton prices and the reduction in the number of hectares in the U.S. planted with cotton. Our results demonstrate that fluctuations in market conditions can cause temporal variation in ecosystem service values even when ecosystem function – in this case bat population numbers – is held constant. Evidence is accumulating, however, of the evolution of pest resistance to Bt cotton, suggesting that the value of bat pest-control services may increase again. This gives rise to an economic option value argument for conserving Mexican free-tailed bat populations. We anticipate that these results will spur discussion about the role of ecosystem services in biodiversity conservation in general, and bat conservation in particular.

  4. Resistance of Trichoplusia ni populations selected by Bacillus thuringiensis sprays to cotton plants expressing pyramided Bacillus thuringiensis toxins Cry1Ac and Cry2Ab.

    PubMed

    Kain, Wendy; Song, Xiaozhao; Janmaat, Alida F; Zhao, Jian-Zhou; Myers, Judith; Shelton, Anthony M; Wang, Ping

    2015-03-01

    Two populations of Trichoplusia ni that had developed resistance to Bacillus thuringiensis sprays (Bt sprays) in commercial greenhouse vegetable production were tested for resistance to Bt cotton (BollGard II) plants expressing pyramided Cry1Ac and Cry2Ab. The T. ni colonies resistant to Bacillus thuringiensis serovar kurstaki formulations were not only resistant to the Bt toxin Cry1Ac, as previously reported, but also had a high frequency of Cry2Ab-resistant alleles, exhibiting ca. 20% survival on BollGard II foliage. BollGard II-resistant T. ni strains were established by selection with BollGard II foliage to further remove Cry2Ab-sensitive alleles in the T. ni populations. The BollGard II-resistant strains showed incomplete resistance to BollGard II, with adjusted survival values of 0.50 to 0.78 after 7 days. The resistance to the dual-toxin cotton plants was conferred by two genetically independent resistance mechanisms: one to Cry1Ac and one to Cry2Ab. The 50% lethal concentration of Cry2Ab for the resistant strain was at least 1,467-fold that for the susceptible T. ni strain. The resistance to Cry2Ab in resistant T. ni was an autosomally inherited, incompletely recessive monogenic trait. Results from this study indicate that insect populations under selection by Bt sprays in agriculture can be resistant to multiple Bt toxins and may potentially confer resistance to multitoxin Bt crops. PMID:25480752

  5. Resistance of Trichoplusia ni Populations Selected by Bacillus thuringiensis Sprays to Cotton Plants Expressing Pyramided Bacillus thuringiensis Toxins Cry1Ac and Cry2Ab

    PubMed Central

    Kain, Wendy; Song, Xiaozhao; Janmaat, Alida F.; Zhao, Jian-Zhou; Myers, Judith; Shelton, Anthony M.

    2014-01-01

    Two populations of Trichoplusia ni that had developed resistance to Bacillus thuringiensis sprays (Bt sprays) in commercial greenhouse vegetable production were tested for resistance to Bt cotton (BollGard II) plants expressing pyramided Cry1Ac and Cry2Ab. The T. ni colonies resistant to Bacillus thuringiensis serovar kurstaki formulations were not only resistant to the Bt toxin Cry1Ac, as previously reported, but also had a high frequency of Cry2Ab-resistant alleles, exhibiting ca. 20% survival on BollGard II foliage. BollGard II-resistant T. ni strains were established by selection with BollGard II foliage to further remove Cry2Ab-sensitive alleles in the T. ni populations. The BollGard II-resistant strains showed incomplete resistance to BollGard II, with adjusted survival values of 0.50 to 0.78 after 7 days. The resistance to the dual-toxin cotton plants was conferred by two genetically independent resistance mechanisms: one to Cry1Ac and one to Cry2Ab. The 50% lethal concentration of Cry2Ab for the resistant strain was at least 1,467-fold that for the susceptible T. ni strain. The resistance to Cry2Ab in resistant T. ni was an autosomally inherited, incompletely recessive monogenic trait. Results from this study indicate that insect populations under selection by Bt sprays in agriculture can be resistant to multiple Bt toxins and may potentially confer resistance to multitoxin Bt crops. PMID:25480752

  6. Utilization of Bt corn residues by grazing beef steers and Bt corn silage and grain by growing beef cattle and lactating dairy cows.

    PubMed

    Folmer, J D; Grant, R J; Milton, C T; Beck, J

    2002-05-01

    Three experiments were conducted to evaluate the impact of the Bacillus thuringiensis (Bt)-11 transformation event in two parental corn hybrids differing in date of maturity on beef and dairy cattle performance. Sixteen lactating Holstein dairy cows in replicated 4 x 4 Latin squares were assigned to four diets in a 2 x 2 factorial arrangement: Bt vs non-Bt trait and early- vs late-maturing corn hybrids. The diets contained 40% of the test corn silage plus 28% corn grain from the same corn hybrid (DM basis). There was no effect of the Bt trait on efficiency of milk production, ruminal pH, acetate:propionate ratio, or in situ digestion kinetics of NDF. The early-maturing corn hybrids resulted in greater total VFA concentrations in the rumen and efficiency of 4% fat-corrected milk production than the later-maturing hybrids (P < 0.05). Sixty-seven steer calves were used in a 70-d corn residue grazing trial for the late-maturing corn hybrids only. Daily BW gain of steers was similar for those grazing Bt and non-Bt corn residues, and the steers exhibited no grazing preference between Bt and non-Bt corn residue. One hundred twenty-eight steer calves were assigned to four silage-based growing diets in a 2 x 2 factorial arrangement: Bt vs non-Bt trait and early- vs late-maturing corn hybrids. The diets contained 90% corn silage and 10% supplement (DM basis). The DMI was higher for steers fed Bt compared with non-Bt hybrids (P < 0.02). An interaction (P < 0.03) was observed for feed efficiency between hybrid genotype and incorporation of the Bt trait. Feed efficiency was greater (P < 0.05) for steers fed the later-maturing non-Bt hybrid compared with the later-maturing Bt hybrid; however, feed efficiency was similar between steers fed early-maturing Bt and non-Bt corn silages. Steers fed the early-maturing hybrid gained 11% faster and were 7% more efficient compared with those fed the late-maturing hybrid. These latter results agree with the dairy experiment in which the

  7. Field efficacy and seasonal expression profiles for terminal leaves of single and double Bacillus thuringiensis toxin cotton genotypes.

    PubMed

    Adamczyk, J J; Adams, L C; Hardee, D D

    2001-12-01

    Examination of commercial Cry1Ac transgenic Bacillus thuringiensis Berliner (Bt) cotton varieties (Bollgard, Monsanto, St. Louis, MO) and an experimental Cry1Ac + Cry2Ab transgenic Bt cotton variety (Bollgard II, Monsanto) for lepidopteran field efficacy was conducted during the 2000 growing season. In addition, a commercially available (Envirologix, Portland, ME) quantification assay (ELISA) was used to measure and profile the expression levels of Cry proteins in two of these varieties ['DP50B, Bollgard'; 'DP50BII, Bollgard II' (Delta & Pine Land, Scott, MS)]. Populations of beet army worms, Spodoptera exigua (Hübner), and soybean loopers, Pseudoplusia includens (Walker), were significantly lower (P < 0.05) in Bollgard II plots compared with Bollgard. Population numbers for fall army worms, Spodoptera frugiperda (J. E. Smith), and salt marsh caterpillars, Estigmene acrea (Drury), were lower in Bollgard II plots compared with Bollgard but means did not differ significantly (P > 0.05). Single and dual-toxin genotypes remained superior (P < 0.05) compared with conventional cotton against the tobacco budworm, Heliothis virescens (F.). The addition of Cry2Ab had no significant (P > 0.05) impact on Cry1Ac expression in Bollgard II compared with Cry1Ac expression in Bollgard. Furthermore, throughout the season Cry2Ab was present at much higher levels in the plant compared with Cry1Ac for Bollgard II plants. Possible species-specific reasons for increased efficacy of Bollgard II over Bollgard are discussed. PMID:11777069

  8. Crop-specific mortality of southern green stink-bug eggs in Bt- and non-Bt cotton, soybean, and peanut

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is a need to characterize the mechanisms underlying population dynamics of stink bugs relative to major crops in the southeastern US. To this end, we investigated predation and parasitism of Southern green stink bug eggs and the agents causing mortality by placing sentinel egg masses in plots ...

  9. A 2-Year Field Study Shows Little Evidence That the Long-Term Planting of Transgenic Insect-Resistant Cotton Affects the Community Structure of Soil Nematodes

    PubMed Central

    Li, Xiaogang; Liu, Biao

    2013-01-01

    Transgenic insect-resistant cotton has been released into the environment for more than a decade in China to effectively control the cotton bollworm (Helicoverpa armigera) and other Lepidoptera. Because of concerns about undesirable ecological side-effects of transgenic crops, it is important to monitor the potential environmental impact of transgenic insect-resistant cotton after commercial release. Our 2-year study included 1 cotton field where non-transgenic cotton had been planted continuously and 2 other cotton fields where transgenic insect-resistant cotton had been planted for different lengths of time since 1997 and since 2002. In 2 consecutive years (2009 and 2010), we took soil samples from 3 cotton fields at 4 different growth stages (seedling, budding, boll-forming and boll-opening stages), collected soil nematodes from soil with the sugar flotation and centrifugation method and identified the soil nematodes to the genus level. The generic composition, individual densities and diversity indices of the soil nematodes did not differ significantly between the 2 transgenic cotton fields and the non-transgenic cotton field, but significant seasonal variation was found in the individual densities of the principal trophic groups and in the diversity indices of the nematodes in all 3 cotton fields. The study used a comparative perspective to monitor the impact of transgenic insect-resistant cotton grown in typical ‘real world’ conditions. The results of the study suggested that more than 10 years of cultivation of transgenic insect-resistant cotton had no significant effects–adverse or otherwise–on soil nematodes. This study provides a theoretical basis for ongoing environmental impact monitoring of transgenic plants. PMID:23613899

  10. Agrobacterium rhizogenes-induced cotton hairy root culture as an alternative tool for cotton functional genomics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although well-accepted as the ultimate method for cotton functional genomics, Agrobacterium tumefaciens-mediated cotton transformation is not widely used for functional analyses of cotton genes and their promoters since regeneration of cotton in tissue culture is lengthy and labor intensive. In cer...

  11. Efficacy of transgenic cotton expressing Cry1Ac and Cry1F insecticidal protein against heliothines (Lepidoptera: Noctuidae).

    PubMed

    Siebert, M Willrich; Nolting, S; Leonard, B R; Braxton, L B; All, J N; Van Duyn, J W; Bradley, J R; Bacheler, J; Huckaba, R M

    2008-12-01

    Cotton, Cossypium hirsutum L, plants expressing Cry1Ac and Cry1F (Phytogen 440W) insecticidal crystal proteins of Bacillus thuringiensis (Bt) Berliner, were evaluated against natural populations of tobacco budworm, Heliothis virescens (F.), and bollworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), across 13 southern U.S. locations that sustained low, moderate, and high infestations. The intrinsic activity of Phytogen 440W was compared with nontreated non-Bt cotton (PSC355) and with management strategies in which supplemental insecticides targeting heliothines were applied to Phytogen 440W and to PSC355 cotton. Infestations were composed primarily of bollworm, which is the least sensitive of the heliothine complex to Cry toxins. Therefore, damage recorded in these studies was primarily due to bollworm. Greater than 75% of all test sites sustained heliothine infestations categorized as moderate to high (10.6-64.0% peak damaged bolls in nontreated PSC355). Phytogen 440W, alone or managed with supplemental insecticide applications, reduced heliothine-damaged plant terminals, squares (flower buds), flowers, and bolls equal to or better (1.0-79.0-fold) than managing a non-Bt cotton variety with foliar insecticides across all infestation environments. Rarely (frequency of < or = 11% averaged across structures), sprayed Phytogen 440W reduced damaged structures compared with nontreated Phytogen 440W. Protection against heliothine-induced plant damage was similar across the three levels of infestation for each viable management strategy, with exception to damaged squares for nontreated Phytogen 440W. In situations of moderate to high heliothine infestations, cotton plants expressing Cry1Ac and Cry1F may sustain higher levels of damage compared with that same variety in low infestations. No significant difference in yield was observed among heliothine management strategies within each infestation level, indicating cotton plants may compensate for those levels of plant

  12. Comparing Gene Expression Profiles Between Bt and non-Bt Rice in Response to Brown Planthopper Infestation

    PubMed Central

    Wang, Fang; Ning, Duo; Chen, Yang; Dang, Cong; Han, Nai-Shun; Liu, Yu'e; Ye, Gong-Yin

    2015-01-01

    Bt proteins are the most widely used insecticidal proteins in transgenic crops for improving insect resistance. We previously observed longer nymphal developmental duration and lower fecundity in brown planthopper (BPH) fed on Bt rice line KMD2, although Bt insecticidal protein Cry1Ab could rarely concentrate in this non-target rice pest. In the present study, we performed microarray analysis in an effort to detect Bt-independent variation, which might render Bt rice more defensive and/or less nutritious to BPH. We detected 3834 and 3273 differentially expressed probe-sets in response to BPH infestation in non-Bt parent Xiushui 11 and Bt rice KMD2, respectively, only 439 of which showed significant differences in expression between rice lines. Our analysis revealed a shift from growth to defense responses in response to BPH infestation, which was also detected in many other studies of plants suffering biotic and abiotic stresses. Chlorophyll biosynthesis and basic metabolism pathways were inhibited in response to infestation. IAA and GA levels decreased as a result of the repression of biosynthesis-related genes or the induction of inactivation-related genes. In accordance with these observations, a number of IAA-, GA-, BR-signaling genes were downregulated in response to BPH. Thus, the growth of rice plants under BPH attack was reduced and defense related hormone signaling like JA, SA and ET were activated. In addition, growth-related hormone signaling pathways, such as GA, BR, and auxin signaling pathways, as well as ABA, were also found to be involved in BPH-induced defense. On the other side, 51 probe-sets (represented 50 genes) that most likely contribute to the impact of Bt rice on BPH were identified, including three early nodulin genes, four lipid metabolic genes, 14 stress response genes, three TF genes and genes with other functions. Two transcription factor genes, bHLH and MYB, together with lipid transfer protein genes LTPL65 and early nodulin gene ENOD

  13. Regulatory considerations surrounding the deployment of Bt-expressing cowpea in Africa: report of the deliberations of an expert panel.

    PubMed

    Huesing, Joseph; Romeis, Jörg; Ellstrand, Norman; Raybould, Alan; Hellmich, Richard; Wolt, Jeff; Ehlers, Jeff; Dabiré, Clémentine; Fatokun, Christian; Hokanson, Karen; Ishiyaku, Mohammad F; Margam, Venu; Obokoh, Nompumelelo; Mignouna, Jacob; Nangayo, Francis; Ouedraogo, Jeremy; Pasquet, Rémy; Pittendrigh, Barry; Schaal, Barbara; Stein, Jeff; Tamò, Manuele; Murdock, Larry

    2011-01-01

    Cowpea (Vigna unguiculata spp unguiculata) is adapted to the drier agro-ecological zones of West Africa where it is a major source of dietary protein and widely used as a fodder crop. Improving the productivity of cowpea can enhance food availability and security in West Africa. Insect predation--predominately from the legume pod borer (Maruca vitrata), flower thrips (Megalurothrips sjostedti) and a complex of pod-sucking bugs (e.g., Clavigralla spp)--is a major yield-limiting factor in West African cowpea production. Dramatic increases in yield are shown when M. vitrata is controlled with insecticides. However, availability, costs, and safety considerations limit pesticides as a viable option for boosting cowpea production. Development of Bt-cowpea through genetic modification (GM) to control the legume pod borer is a promising approach to cowpea improvement. Cowpea expressing the lepidopteran-active Cry1Ab protein from Bacillus thuringiensis is being developed as a first generation Bt-cowpea crop for West Africa. Appropriate stewardship of Bt-cowpea to assure its sustainability under West African conditions is critical to its successful development. A first step in this process is an environmental risk assessment to determine the likelihood and magnitude of adverse effects of the Cry1Ab protein on key environmental protection goals in West Africa. Here we describe the results of an expert panel convened in 2009 to develop the problem formulation phase for Bt-cowpea and to address specific issues around gene flow, non-target arthropods, and insect resistance management. PMID:22179194

  14. Eco-physiological response of two marine bivalves to acute exposition to commercial Bt-based pesticide.

    PubMed

    Manachini, B; Arizza, V; Rinaldi, A; Montalto, V; Sarà, G

    2013-02-01

    Microbial products based on the entomopathogenic bacterium Bacillus thuringiensis (Bt) are among the most common biopesticides used worldwide to suppress insect pests in forests, horticulture and agricultural crops. Some of the effects of commercial Bt have been recorded for terrestrial and freshwater non-target organisms but little research is available on marine fauna. Nevertheless, due to the contiguity of agro-ecosystems and coastal habitats, marine fauna may be highly influenced by this control method. We studied the effect of a commercial Bt product on the physiological and ecological responses and the energy budget of two of the most frequent marine intertidal bivalves in the Mediterranean, the native Mytilaster minimus and the invasive Brachidontes pharaonis. To test the effects experimentally, we simulated the worst scenarios possible using the average dose applied to fields and a hypothetical accumulation dose. The results showed the feeding rates of both species were affected detrimentally by the different experimental conditions; higher concentrations led to higher respiration rates, however neither species showed any significant difference in excretion rates. The biopesticide had a significant effect on the energy budget, the values decreasing with doses. In addition, it led to high mortality for the worst treatments and, in both species, induced significantly higher cardiac activity than in the controls. These results indicate a measurable effect of Bt commercial products on marine organisms, and great attention should be paid to biopesticides composed by entomopathogenic bacteria and addictive compounds. In addition, the results highlight the urgent need to study not only the effects of anthropogenic pressures on target organisms but also to extend our view to other ecosystems not expected to be influenced. Gaining data at the organismal level should help increase the sustainability of pest control and reduce the consequences of side-effects. PMID

  15. Perspectives of the International Cotton Genome Initiative

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton (Gossypium spp.), an immensely important crop worldwide, has lacked representation by an international research organization that could facilitate global collaboration and coordination, and it has lagged behind other major crops in genome research. For these reasons, the International Cotton...

  16. Administrative Ecology

    ERIC Educational Resources Information Center

    McGarity, Augustus C., III; Maulding, Wanda

    2007-01-01

    This article discusses how all four facets of administrative ecology help dispel the claims about the "impossibility" of the superintendency. These are personal ecology, professional ecology, organizational ecology, and community ecology. Using today's superintendency as an administrative platform, current literature describes a preponderance of…

  17. 46 CFR 15.1105 - Familiarization and basic training (BT).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... the provisions of 46 CFR part 28 on instructions, drills, and safety orientation are deemed to be in... (BT). (a) Onboard a seagoing vessel to which this subpart applies, no person may assign any person to... onboard about elementary safety matters and understand informational symbols, signs, and alarm...

  18. Status of the global cotton germplasm resources

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The cultivated Gossypium spp. (cotton) represents the single most important, natural fiber crop in the world. In addition to its fiber, the oil and protein portion of the cottonseed also represents significant economic value. To protect the world-wide economic value of cotton fiber and cotton byprod...

  19. Spindle speed effects on cotton fiber quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three cotton varieties were grown under furrow-irrigated conditions in southern New Mexico and hand-harvested in a way that kept individual bolls intact. The cotton bolls were conditioned in a controlled atmosphere and then subjected to a single cotton picker spindle operating at a speed of 1000 to...

  20. RETROSPECTIVE VIEW OF COTTON GIN DRYERS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper reviews gin dryer designs and compiles most of the significant research conducted on the drying of seed cotton at cotton gins since about 1928. it describes the operation of various types of dryers and gives a critical appraisal of dryer designs that may be useful at current cotton gins....

  1. Bioinspiration and Biomimicry: Possibilities for Cotton Byproducts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The byproducts from cotton gins have commonly been referred to as cotton gin trash or cotton gin waste primarily because the lint and seed were the main focus of the operation and the byproducts were a financial liability that did not have a consistent market. Even though the byproducts were called ...

  2. Toward cotton molecular breeding: challenges and opportunities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton (Gossypium spp) is the leading natural fiber in the global textile market, but progress in the development and applications of molecular tools to improve cotton lags behind other major crop plants. The slow progress is in part due to cotton's large complex allotetraploid genome of 26 partial...

  3. Trash particle distribution measurements in ginned cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A beltwide commercial cotton gin sampling project was initiated for the 2005-06 and 2006-07 ginning seasons to assess the changes in upland cotton quality during the ginning process and throughout the ginning season. The Cotton Trash Identification System (CTIS) developed at the USDA-ARS Southwester...

  4. Greige cotton comber noils for sustainable nonwovens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To increase utilization of cotton in value-added nonwoven products, a study was conducted to examine the feasibility of utilizing cotton textile processing/combing bye-product known as griege cotton comber noils. The study was conducted on a commercial-grade, textile-cum-nonwovens pilot plant and ha...

  5. Global view of cotton germplasm resources

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper reports the status of several large cotton germplasm collections present across the world. Cotton germplasm collections discussed include those from the US, India, France, China, Australia, Uzbekistan, and Brazil. These collections represent a large portion of the curated cotton germpla...

  6. Microbial control of the cotton leafworm Spodoptera littoralis (Boisd.) by Egyptian Bacillus thuringiensis isolates.

    PubMed

    Alfazairy, Ahlam A; El-Ahwany, Amani M D; Mohamed, Eman A; Zaghloul, Heba A H; El-Helow, Ehab R

    2013-03-01

    Four local Bacillus thuringiensis (Bt) isolates that had been serologically identified as Bt var. kurstaki (Btk2, Btk3, and Btk66) and Bt var. mexicanensis (Btm27), in addition to two reference strains (4D20 and 4AC1), were laboratory assayed as microbial control agents against the Egyptian cotton leafworm Spodoptera littoralis (Boisd.). Polymerase chain reaction (PCR) amplification analysis revealed that each of the six experimental strains carries, at least, a cry1 type gene which expresses a protein toxin active against lepidopterous insects. Additionally, PCR amplification results demonstrated that 4D20 and Btk66 contain the Lepidoptera- and Diptera-active cry2 type gene and that Btk66 contains Coleoptera-active cry7 and cry8 genes. Among the six strains, Btk66 and Btm27 were the most promising microbial control agents against S. littoralis. The present findings were the first to report that Btm27 (classified as B. thuringiensis var. mexicanensis) is a very potent microbial control agent against S. littoralis-tested larvae. For more characterization of these two isolates, the sspO gene was investigated as a molecular chronometer. The DNA sequencing results proved that Btk66 and Btm27 carry sspO open reading frames with identical nucleotide sequences, suggesting a strong phylogenetic relationship between the two strains. PMID:22983675

  7. Organic cotton systems improved soil properties vis-a-vis the modern systems

    NASA Astrophysics Data System (ADS)

    Blaise, D.; Venugopalan, M. V.; Singh, J. V.; Narkhedkar, N. G.; Velmourougane, K.

    2012-04-01

    India is the largest cotton growing country in the world. Traditionally, cotton in India was grown with minimal inputs and resources available on farm were put to efficient use. Advent of hybrids and Bt cotton revolutionized cotton production in the country and lead to heavy reliance on external inputs. However, there is a growing awareness of the detrimental effects of excessive use of pesticides and fertilizers. This is leading to growing interest in organic cultivation of crops. An organic system (OS) was compared with the modern systems (MS) for changes in the soil physical, chemical and biological properties in field experiments conducted both on station and farmers fields in Maharashtra, India on rain dependent cotton grown on Vertisols. Soil samples of the organic plots had significantly greater C content than the MS plots relying on mineral fertilizers and pesticides. Similarly, other nutrients were also greater in the OS than the MS across locations. Most of the increases were noticed in the top 30 cm of the soil profile. Interestingly, enrichment of the soil at lower depths was noticed in the OS which could be due to the surface creep of soils through the cracks in the Vertisols. With regard to the physical properties, water-stable aggregates and mean weight diameter in the MS were significantly lesser than the OS. Differences were restricted to the top 20 cm. Soil biological properties of the two systems were compared through the enzyme assays such as the dehydrogenase, glucosidase, phosphatase, sulfatase periodically during the crop growing season. All the enzyme assays indicated greater activities in the OS than the MS. Further, microfauna (nematodes) monitored indicated less of plant parasitic nematodes in the OS than the MS. Excessive tillage followed in the MS did bring about a reduction in the nematode numbers. But the systems had more parasitic nematodes.

  8. Genetic markers for western corn rootworm resistance to Bt toxin.

    PubMed

    Flagel, Lex E; Swarup, Shilpa; Chen, Mao; Bauer, Christopher; Wanjugi, Humphrey; Carroll, Matthew; Hill, Patrick; Tuscan, Meghan; Bansal, Raman; Flannagan, Ronald; Clark, Thomas L; Michel, Andrew P; Head, Graham P; Goldman, Barry S

    2015-03-01

    Western corn rootworm (WCR) is a major maize (Zea mays L.) pest leading to annual economic losses of more than 1 billion dollars in the United States. Transgenic maize expressing insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt) are widely used for the management of WCR. However, cultivation of Bt-expressing maize places intense selection pressure on pest populations to evolve resistance. Instances of resistance to Bt toxins have been reported in WCR. Developing genetic markers for resistance will help in characterizing the extent of existing issues, predicting where future field failures may occur, improving insect resistance management strategies, and in designing and sustainably implementing forthcoming WCR control products. Here, we discover and validate genetic markers in WCR that are associated with resistance to the Cry3Bb1 Bt toxin. A field-derived WCR population known to be resistant to the Cry3Bb1 Bt toxin was used to generate a genetic map and to identify a genomic region associated with Cry3Bb1 resistance. Our results indicate that resistance is inherited in a nearly recessive manner and associated with a single autosomal linkage group. Markers tightly linked with resistance were validated using WCR populations collected from Cry3Bb1 maize fields showing significant WCR damage from across the US Corn Belt. Two markers were found to be correlated with both diet (R2 = 0.14) and plant (R2 = 0.23) bioassays for resistance. These results will assist in assessing resistance risk for different WCR populations, and can be used to improve insect resistance management strategies. PMID:25566794

  9. Genetic Markers for Western Corn Rootworm Resistance to Bt Toxin

    PubMed Central

    Flagel, Lex E.; Swarup, Shilpa; Chen, Mao; Bauer, Christopher; Wanjugi, Humphrey; Carroll, Matthew; Hill, Patrick; Tuscan, Meghan; Bansal, Raman; Flannagan, Ronald; Clark, Thomas L.; Michel, Andrew P.; Head, Graham P.; Goldman, Barry S.

    2015-01-01

    Western corn rootworm (WCR) is a major maize (Zea mays L.) pest leading to annual economic losses of more than 1 billion dollars in the United States. Transgenic maize expressing insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt) are widely used for the management of WCR. However, cultivation of Bt-expressing maize places intense selection pressure on pest populations to evolve resistance. Instances of resistance to Bt toxins have been reported in WCR. Developing genetic markers for resistance will help in characterizing the extent of existing issues, predicting where future field failures may occur, improving insect resistance management strategies, and in designing and sustainably implementing forthcoming WCR control products. Here, we discover and validate genetic markers in WCR that are associated with resistance to the Cry3Bb1 Bt toxin. A field-derived WCR population known to be resistant to the Cry3Bb1 Bt toxin was used to generate a genetic map and to identify a genomic region associated with Cry3Bb1 resistance. Our results indicate that resistance is inherited in a nearly recessive manner and associated with a single autosomal linkage group. Markers tightly linked with resistance were validated using WCR populations collected from Cry3Bb1 maize fields showing significant WCR damage from across the US Corn Belt. Two markers were found to be correlated with both diet (R2 = 0.14) and plant (R2 = 0.23) bioassays for resistance. These results will assist in assessing resistance risk for different WCR populations, and can be used to improve insect resistance management strategies. PMID:25566794

  10. Spatiotemporal patterns and dispersal of stink bugs (Heteroptera: Pentatomidae) in peanut-cotton farmscapes.

    PubMed

    Tillman, P G; Northfield, T D; Mizell, R F; Riddle, T C

    2009-08-01

    In the southeast United States, a field of peanuts, Arachis hypogaea L., is often closely associated with a field of cotton, Gossypium hirsutum L. The objective of this 4-yr on-farm study was to examine and compare the spatiotemporal patterns and dispersal of the southern green stink bug, Nezara viridula L., and the brown stink bug, Euschistus servus (Say), in six of these peanut-cotton farmscapes. GS(+) Version 9 was used to generate interpolated estimates of stink bug density by inverse distance weighting. Interpolated stink bug population raster maps were constructed using ArcMap Version 9.2. This technique was used to show any change in distribution of stink bugs in the farmscape over time. SADIE (spatial analysis by distance indices) methodology was used to examine spatial aggregation of individual stink bug species and spatial association of the two stink bug species in the individual crops. Altogether, the spatiotemporal analyses for the farmscapes showed that some N. viridula and E. servus nymphs and adults that develop in peanuts disperse into cotton. When these stink bugs disperse from peanuts into cotton, they aggregate in cotton at the interface, or common boundary, of the two crops while feeding on cotton bolls. Therefore, there is a pronounced edge effect observed in the distribution of stink bugs as they colonize the new crop, cotton. The driving force for the spatiotemporal distribution and dispersal of both stink bug species in peanut-cotton farmscapes seems to be availability of food in time and space mitigated by landscape structure. Thus, an understanding of farmscape ecology of stink bugs and their natural enemies is necessary to strategically place, in time and space, biologically based management strategies that control stink bug populations while conserving natural enemies and the environment and reducing off-farm inputs. PMID:19689882

  11. Field-based assessment of resistance to Bt Corn by Western Corn Rootworm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Western corn rootworm, Diabrotica virgifera virgifera LeConte, is a serious pest of corn and is managed with Bt corn that produce insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt). Beginning in 2009, severe injury to Bt corn producing Cry3Bb1 was observed in some cornfields ...

  12. Effects of Transgenic Bt Rice on Nontarget Rhopalosiphum maidis (Homoptera: Aphididae).

    PubMed

    Ren, Shao-Peng; Yang, Fan; Gao, Ming-Qing; Pu, De-Qiang; Shi, Min; Ye, Gong-Yin; Shen, Zhi-Cheng; Chen, Xue-Xin

    2016-08-01

    The effects of three transgenic Bacillus thuringiensis (Bt) rice lines, KMD1, KMD2, and G8-7, on biological parameters and population dynamics of nontarget insect, Rhopalosiphum maidis (Fitch) (Homoptera: Aphididae), were investigated in the laboratory and field. No significant differences were found between Bt and non-Bt rice lines for aphid survival. The developmental time of R. maidis that fed on KMD1 and KMD2 did not differ significantly from those of the individuals feeding on the parental variety Xiushui11, but significantly prolonged developmental time was observed on G8-7 as compared with its parental variety Xiushui110. Aphid fecundity was significantly higher on Bt than on parental rice. A 2-yr field survey indicated that Bt rice did not significantly affect the population dynamics of R. maidis in comparison with non-Bt rice. Additionally, guttation droplets of Bt rice and aphids feeding on Bt rice were analyzed for presence of Cry1Ab using ELISA. No Cry1Ab protein was found in aphid adults feeding on Bt rice lines both in the laboratory and field. By using the guttation droplets from the top of rice seedlings, we designed a novel method to collect phloem sap, and found that relatively low concentrations were detected in the guttation droplets from Bt rice lines. In conclusion, although the Bt rice lines tested in this study stimulate the fecundity of R. maidis, the aphid population density did not increase in Bt rice fields. PMID:27389683

  13. Ecological Schoolyards.

    ERIC Educational Resources Information Center

    Danks, Sharon Gamson

    2000-01-01

    Presents design guidelines and organizational and site principles for creating schoolyards where students can learn about ecology. Principles for building schoolyard ecological systems are described. (GR)

  14. Test Takers' Attitudes about the TOEFL iBT[TM]. TOEFL iBT Research Report. RR-10-2

    ERIC Educational Resources Information Center

    Stricker, Lawrence J.; Attali, Yigal

    2010-01-01

    The principal aims of this study, a conceptual replication of an earlier investigation of the TOEFL[R] computer-based test, or TOEFL CBT, in Buenos Aires, Cairo, and Frankfurt, were to assess test takers' reported acceptance of the TOEFL Internet-based test, or TOEFL iBT[TM], and its associations with possible determinants of this acceptance and…

  15. FUM Gene Expression Profile and Fumonisin Production by Fusarium verticillioides Inoculated in Bt and Non-Bt Maize

    PubMed Central

    Rocha, Liliana O.; Barroso, Vinícius M.; Andrade, Ludmila J.; Pereira, Gustavo H. A.; Ferreira-Castro, Fabiane L.; Duarte, Aildson P.; Michelotto, Marcos D.; Correa, Benedito

    2016-01-01

    This study aimed to determine the levels of fumonisins produced by Fusarium verticillioides and FUM gene expression on Bt (Bacillus thuringiensis) and non-Bt maize, post harvest, during different periods of incubation. Transgenic hybrids 30F35 YG, 2B710 Hx and their isogenic (30F35 and 2B710) were collected from the field and a subset of 30 samples selected for the experiments. Maize samples were sterilized by gamma radiation at a dose of 20 kGy. Samples were then inoculated with F. verticillioides and analyzed under controlled conditions of temperature and relative humidity for fumonisin B1 and B2 (FB1 and FB2) production and FUM1, FUM3, FUM6, FUM7, FUM8, FUM13, FUM14, FUM15, and FUM19 expression. 2B710 Hx and 30F35 YG kernel samples were virtually intact when compared to the non-Bt hybrids that came from the field. Statistical analysis showed that FB1 production was significantly lower in 30F35 YG and 2B710 Hx than in the 30F35 and 2B710 hybrids (P < 0.05). However, there was no statistical difference for FB2 production (P > 0.05). The kernel injuries observed in the non-Bt samples have possibly facilitated F. verticillioides penetration and promoted FB1 production under controlled conditions. FUM genes were expressed by F. verticillioides in all of the samples. However, there was indication of lower expression of a few FUM genes in the Bt hybrids; and a weak association between FB1 production and the relative expression of some of the FUM genes were observed in the 30F35 YG hybrid. PMID:26779158

  16. FUM Gene Expression Profile and Fumonisin Production by Fusarium verticillioides Inoculated in Bt and Non-Bt Maize.

    PubMed

    Rocha, Liliana O; Barroso, Vinícius M; Andrade, Ludmila J; Pereira, Gustavo H A; Ferreira-Castro, Fabiane L; Duarte, Aildson P; Michelotto, Marcos D; Correa, Benedito

    2015-01-01

    This study aimed to determine the levels of fumonisins produced by Fusarium verticillioides and FUM gene expression on Bt (Bacillus thuringiensis) and non-Bt maize, post harvest, during different periods of incubation. Transgenic hybrids 30F35 YG, 2B710 Hx and their isogenic (30F35 and 2B710) were collected from the field and a subset of 30 samples selected for the experiments. Maize samples were sterilized by gamma radiation at a dose of 20 kGy. Samples were then inoculated with F. verticillioides and analyzed under controlled conditions of temperature and relative humidity for fumonisin B1 and B2 (FB1 and FB2) production and FUM1, FUM3, FUM6, FUM7, FUM8, FUM13, FUM14, FUM15, and FUM19 expression. 2B710 Hx and 30F35 YG kernel samples were virtually intact when compared to the non-Bt hybrids that came from the field. Statistical analysis showed that FB1 production was significantly lower in 30F35 YG and 2B710 Hx than in the 30F35 and 2B710 hybrids (P < 0.05). However, there was no statistical difference for FB2 production (P > 0.05). The kernel injuries observed in the non-Bt samples have possibly facilitated F. verticillioides penetration and promoted FB1 production under controlled conditions. FUM genes were expressed by F. verticillioides in all of the samples. However, there was indication of lower expression of a few FUM genes in the Bt hybrids; and a weak association between FB1 production and the relative expression of some of the FUM genes were observed in the 30F35 YG hybrid. PMID:26779158

  17. Relevance of Bt toxin interaction studies for environmental risk assessment of genetically modified crops.

    PubMed

    De Schrijver, Adinda; De Clercq, Patrick; de Maagd, Ruud A; van Frankenhuyzen, Kees

    2015-12-01

    In recent years, different Bacillus thuringiensis (Bt) toxin-encoding genes have been combined or 'stacked' in genetically modified (GM) crops. Synergism between Bt proteins may occur and thereby increase the impact of the stacked GM event on nontarget invertebrates compared to plants expressing a single Bt gene. On the basis of bioassay data available for Bt toxins alone or in combination, we argue that the current knowledge of Bt protein interactions is of limited relevance in environmental risk assessment (ERA). PMID:26032006

  18. Utilizing the assassin bug, Pristhesancus plagipennis (Hemiptera: Reduviidae), as a biological control agent within an integrated pest management programme for Helicoverpa spp. (Lepidoptera: Noctuidae) and Creontiades spp. (Hemiptera: Miridae) in cotton.

    PubMed

    Grundy, P R

    2007-06-01

    Helicoverpa spp. and mirids, Creontiades spp., have been difficult to control biologically in cotton due to their unpredictable temporal abundance combined with a cropping environment often made hostile by frequent usage of broad spectrum insecticides. To address this problem, a range of new generation insecticides registered for use in cotton were tested for compatibility with the assassin bug, Pristhesancus plagipennis (Walker), a potential biological control agent for Helicoverpa spp. and Creontiades spp. Indoxacarb, pyriproxifen, buprofezin, spinosad and fipronil were found to be of low to moderate toxicity on P. plagipennis whilst emamectin benzoate, abamectin, diafenthiuron, imidacloprid and omethaote were moderate to highly toxic. Inundative releases of P. plagipennis integrated with insecticides identified as being of low toxicity were then tested and compared with treatments of P. plagipennis and the compatible insecticides used alone, conventionally sprayed usage practice and an untreated control during two field experiments in cotton. The biological control provided by P. plagipennis nymphs when combined with compatible insecticides provided significant (P<0.001) reductions in Helicoverpa and Creontiades spp. on cotton and provided equivalent yields to conventionally sprayed cotton with half of the synthetic insecticide input. Despite this, the utilization of P. plagipennis in cotton as part of an integrated pest management programme remains unlikely due to high inundative release costs relative to other control technologies such as insecticides and transgenic (Bt) cotton varieties. PMID:17524159

  19. The Speaking Section of the TOEFL iBT[TM] (SSTiBT): Test-Takers' Reported Strategic Behaviors. TOEFL iBT[TM] Research Report. RR-09-30

    ERIC Educational Resources Information Center

    Swain, Merrill; Huang, Li-Shih; Barkaoui, Khaled; Brooks, Lindsay; Lapkin, Sharon

    2009-01-01

    This study responds to the Test of English as a Foreign Language[TM] (TOEFL[R]) research agenda concerning the need to understand the processes and knowledge that test-takers utilize. Specifically, it investigates the strategic behaviors test-takers reported using when taking the Speaking section of the TOEFL iBT[TM] (SSTiBT). It also investigates…

  20. The effect of Bt-transgene introgression on plant growth and reproduction in wild Brassica juncea.

    PubMed

    Liu, Yong-Bo; Darmency, Henry; Stewart, C Neal; Wei, Wei; Tang, Zhi-Xi; Ma, Ke-Ping

    2015-06-01

    This study aims to investigate the relative plant growth and reproduction of insect-resistant and susceptible plants following the introgression of an insect-resistance Bt-transgene from Brassica napus, oilseed rape, to wild Brassica juncea. The second backcrossed generation (BC2) from a single backcross family was grown in pure and mixed stands of Bt-transgenic and non-transgenic siblings under two insect treatments. Various proportions of Bt-transgenic plants were employed in mixed stands to study the interaction between resistant and susceptible plants. In the pure stands, Bt-transgenic BC2 plants performed better than non-transgenic plants with or without insect treatments. In mixed stands, Bt-transgenic BC2 plants produced fewer seeds than their non-Bt counterparts at low proportions of Bt-transgenic BC2 plants in the absence of insects. Reproductive allocation of non-transgenic plants marginally increased with increasing proportions of Bt-transgenic plants under herbivore pressure, which resulted in increased total biomass and seed production per stand. The results showed that the growth of non-transgenic plants was protected by Bt-transgenic plants under herbivore pressure. The Bt-transgene might not be advantageous in mixed stands of backcrossed hybrids; thus transgene introgression would not be facilitated when herbivorous insects are not present. However, a relatively large initial population of Bt-transgenic plants might result in transgene persistence when target herbivores are present. PMID:25487040

  1. The Cotton Ginning Industry: Past, Present, and Future

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The cotton ginning industry has adopted many changes in cotton production, processing and marketing over the past years. Current trends show reduced cotton acreage, shifts in cotton production regions, and changes in cotton markets. To be competitive, gins must look for every opportunity to improv...

  2. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature on demand by CCC but no later than May 31...

  3. 7 CFR 1427.165 - Eligible seed cotton.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Eligible seed cotton. 1427.165 Section 1427.165... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.165 Eligible seed cotton. (a) Seed cotton pledged as collateral for a loan must be tendered to CCC by...

  4. 7 CFR 1205.314 - Cotton-producing State.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Cotton-producing State. 1205.314 Section 1205.314... AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.314 Cotton-producing State. Cotton-producing...

  5. 7 CFR 27.46 - Cotton withdrawn from storage.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Cotton withdrawn from storage. 27.46 Section 27.46... REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Cotton Class Certificates § 27.46 Cotton withdrawn from storage. The exchange inspection agency under the supervision or control...

  6. 7 CFR 1427.9 - Classification of cotton.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Classification of cotton. 1427.9 Section 1427.9... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Nonrecourse Cotton Loan and Loan Deficiency Payments § 1427.9 Classification of cotton. (a) All cotton tendered for loan and loan...

  7. 7 CFR 27.46 - Cotton withdrawn from storage.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Cotton withdrawn from storage. 27.46 Section 27.46... REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Cotton Class Certificates § 27.46 Cotton withdrawn from storage. The exchange inspection agency under the supervision or control...

  8. 7 CFR 27.37 - Cotton reduced in grade.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Cotton reduced in grade. 27.37 Section 27.37... REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Classification and Micronaire Determinations § 27.37 Cotton reduced in grade. If cotton be reduced in grade, by reason of the presence...

  9. 7 CFR 1205.314 - Cotton-producing State.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Cotton-producing State. 1205.314 Section 1205.314... AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.314 Cotton-producing State. Cotton-producing...

  10. 7 CFR 28.106 - Universal cotton standards.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Universal cotton standards. 28.106 Section 28.106... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Regulations Under the United States Cotton Standards Act Practical Forms of Cotton Standards § 28.106 Universal cotton standards. Whenever any of the official...

  11. 7 CFR 28.178 - Submission of cotton samples.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Submission of cotton samples. 28.178 Section 28.178... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Classification for Foreign Growth Cotton § 28.178 Submission of cotton samples. Samples of cotton submitted to a Classing Office for classification...

  12. 7 CFR 1205.342 - Certification of cotton importer organizations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Certification of cotton importer organizations. 1205... COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Certification of Cotton Producer Organization § 1205.342 Certification of cotton importer organizations. Any importer organization may...

  13. 7 CFR 28.105 - Practical forms of cotton standards.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Practical forms of cotton standards. 28.105 Section 28... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Regulations Under the United States Cotton Standards Act Practical Forms of Cotton Standards § 28.105 Practical forms of cotton standards. (a) Practical forms of...

  14. 7 CFR 1205.314 - Cotton-producing State

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Cotton-producing State 1205.314 Section 1205.314... AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.314 Cotton-producing State Cotton-producing...

  15. 7 CFR 28.39 - Cotton reduced in grade.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Cotton reduced in grade. 28.39 Section 28.39... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Regulations Under the United States Cotton Standards Act Classification § 28.39 Cotton reduced in grade. If cotton be reduced in grade, by reason of the presence...

  16. 7 CFR 1205.342 - Certification of cotton importer organizations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Certification of cotton importer organizations. 1205... COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Certification of Cotton Producer Organization § 1205.342 Certification of cotton importer organizations. Any importer organization may...

  17. 7 CFR 28.40 - Terms defined; cotton classification.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Terms defined; cotton classification. 28.40 Section 28... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Regulations Under the United States Cotton Standards Act Classification § 28.40 Terms defined; cotton classification. For the purposes of classification of any cotton...

  18. 7 CFR 28.39 - Cotton reduced in grade.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Cotton reduced in grade. 28.39 Section 28.39... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Regulations Under the United States Cotton Standards Act Classification § 28.39 Cotton reduced in grade. If cotton be reduced in grade, by reason of the presence...

  19. 7 CFR 1205.342 - Certification of cotton importer organizations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Certification of cotton importer organizations. 1205... COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Certification of Cotton Producer Organization § 1205.342 Certification of cotton importer organizations. Any importer organization may...

  20. 7 CFR 1205.402 - Determination of Cotton Board membership.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Determination of Cotton Board membership. 1205.402... COTTON RESEARCH AND PROMOTION Members of Cotton Board § 1205.402 Determination of Cotton Board membership. (a) In determining whether any cotton-producing state is entitled to be represented by more than...

  1. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature on demand by CCC but no later than May 31...

  2. 7 CFR 27.73 - Supervision of transfers of cotton.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Supervision of transfers of cotton. 27.73 Section 27... REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Postponed Classification § 27.73 Supervision of transfers of cotton. Whenever the owner of any cotton inspected and sampled...

  3. 7 CFR 28.178 - Submission of cotton samples.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Submission of cotton samples. 28.178 Section 28.178... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Classification for Foreign Growth Cotton § 28.178 Submission of cotton samples. Samples of cotton submitted to a Classing Office for classification...

  4. 7 CFR 1205.342 - Certification of cotton importer organizations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Certification of cotton importer organizations. 1205... COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Certification of Cotton Producer Organization § 1205.342 Certification of cotton importer organizations. Any importer organization may...

  5. 7 CFR 28.106 - Universal cotton standards.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Universal cotton standards. 28.106 Section 28.106... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Regulations Under the United States Cotton Standards Act Practical Forms of Cotton Standards § 28.106 Universal cotton standards. Whenever any of the official...

  6. 7 CFR 1427.9 - Classification of cotton.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Classification of cotton. 1427.9 Section 1427.9... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Nonrecourse Cotton Loan and Loan Deficiency Payments § 1427.9 Classification of cotton. (a) All cotton tendered for loan and loan...

  7. 7 CFR 1427.165 - Eligible seed cotton.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Eligible seed cotton. 1427.165 Section 1427.165... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.165 Eligible seed cotton. (a) Seed cotton pledged as collateral for a loan must be tendered to CCC by...

  8. 7 CFR 27.37 - Cotton reduced in grade.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Cotton reduced in grade. 27.37 Section 27.37... REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Classification and Micronaire Determinations § 27.37 Cotton reduced in grade. If cotton be reduced in grade, by reason of the presence...

  9. 7 CFR 27.73 - Supervision of transfers of cotton.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Supervision of transfers of cotton. 27.73 Section 27... REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Postponed Classification § 27.73 Supervision of transfers of cotton. Whenever the owner of any cotton inspected and sampled...

  10. 7 CFR 28.40 - Terms defined; cotton classification.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Terms defined; cotton classification. 28.40 Section 28... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Regulations Under the United States Cotton Standards Act Classification § 28.40 Terms defined; cotton classification. For the purposes of classification of any cotton...

  11. 7 CFR 1427.9 - Classification of cotton.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Classification of cotton. 1427.9 Section 1427.9... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Nonrecourse Cotton Loan and Loan Deficiency Payments § 1427.9 Classification of cotton. (a) All cotton tendered for loan and loan...

  12. 7 CFR 1427.165 - Eligible seed cotton.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Eligible seed cotton. 1427.165 Section 1427.165... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.165 Eligible seed cotton. (a) Seed cotton pledged as collateral for a loan must be tendered to CCC by...

  13. 7 CFR 1205.314 - Cotton-producing State.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Cotton-producing State. 1205.314 Section 1205.314... AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.314 Cotton-producing State. Cotton-producing...

  14. 7 CFR 1205.314 - Cotton-producing State.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Cotton-producing State. 1205.314 Section 1205.314... AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.314 Cotton-producing State. Cotton-producing...

  15. 7 CFR 1427.165 - Eligible seed cotton.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Eligible seed cotton. 1427.165 Section 1427.165... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.165 Eligible seed cotton. (a) Seed cotton pledged as collateral for a loan must be tendered to CCC by...

  16. 7 CFR 1205.402 - Determination of Cotton Board membership.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Determination of Cotton Board membership. 1205.402... COTTON RESEARCH AND PROMOTION Members of Cotton Board § 1205.402 Determination of Cotton Board membership. (a) In determining whether any cotton-producing state is entitled to be represented by more than...

  17. 7 CFR 28.105 - Practical forms of cotton standards.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Practical forms of cotton standards. 28.105 Section 28... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Regulations Under the United States Cotton Standards Act Practical Forms of Cotton Standards § 28.105 Practical forms of cotton standards. (a) Practical forms of...

  18. 7 CFR 27.46 - Cotton withdrawn from storage.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Cotton withdrawn from storage. 27.46 Section 27.46... REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Cotton Class Certificates § 27.46 Cotton withdrawn from storage. The exchange inspection agency under the supervision or control...

  19. 7 CFR 1205.402 - Determination of Cotton Board membership.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Determination of Cotton Board membership. 1205.402... COTTON RESEARCH AND PROMOTION Members of Cotton Board § 1205.402 Determination of Cotton Board membership. (a) In determining whether any cotton-producing state is entitled to be represented by more than...

  20. 7 CFR 28.39 - Cotton reduced in grade.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Cotton reduced in grade. 28.39 Section 28.39... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Regulations Under the United States Cotton Standards Act Classification § 28.39 Cotton reduced in grade. If cotton be reduced in grade, by reason of the presence...

  1. 7 CFR 28.106 - Universal cotton standards.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Universal cotton standards. 28.106 Section 28.106... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Regulations Under the United States Cotton Standards Act Practical Forms of Cotton Standards § 28.106 Universal cotton standards. Whenever any of the official...

  2. 7 CFR 1205.402 - Determination of Cotton Board membership.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Determination of Cotton Board membership. 1205.402... COTTON RESEARCH AND PROMOTION Members of Cotton Board § 1205.402 Determination of Cotton Board membership. (a) In determining whether any cotton-producing state is entitled to be represented by more than...

  3. 7 CFR 28.105 - Practical forms of cotton standards.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Practical forms of cotton standards. 28.105 Section 28... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Regulations Under the United States Cotton Standards Act Practical Forms of Cotton Standards § 28.105 Practical forms of cotton standards. (a) Practical forms of...

  4. 7 CFR 28.178 - Submission of cotton samples.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Submission of cotton samples. 28.178 Section 28.178... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Classification for Foreign Growth Cotton § 28.178 Submission of cotton samples. Samples of cotton submitted to a Classing Office for classification...

  5. 7 CFR 28.106 - Universal cotton standards.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Universal cotton standards. 28.106 Section 28.106... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Regulations Under the United States Cotton Standards Act Practical Forms of Cotton Standards § 28.106 Universal cotton standards. Whenever any of the official...

  6. 7 CFR 28.40 - Terms defined; cotton classification.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Terms defined; cotton classification. 28.40 Section 28... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Regulations Under the United States Cotton Standards Act Classification § 28.40 Terms defined; cotton classification. For the purposes of classification of any cotton...

  7. 7 CFR 28.178 - Submission of cotton samples.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Submission of cotton samples. 28.178 Section 28.178... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Classification for Foreign Growth Cotton § 28.178 Submission of cotton samples. Samples of cotton submitted to a Classing Office for classification...

  8. 7 CFR 27.37 - Cotton reduced in grade.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Cotton reduced in grade. 27.37 Section 27.37... REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Classification and Micronaire Determinations § 27.37 Cotton reduced in grade. If cotton be reduced in grade, by reason of the presence...

  9. 7 CFR 28.39 - Cotton reduced in grade.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Cotton reduced in grade. 28.39 Section 28.39... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Regulations Under the United States Cotton Standards Act Classification § 28.39 Cotton reduced in grade. If cotton be reduced in grade, by reason of the presence...

  10. 7 CFR 28.40 - Terms defined; cotton classification.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Terms defined; cotton classification. 28.40 Section 28... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Regulations Under the United States Cotton Standards Act Classification § 28.40 Terms defined; cotton classification. For the purposes of classification of any cotton...

  11. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature on demand by CCC but no later than May 31...

  12. 7 CFR 1427.9 - Classification of cotton.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Classification of cotton. 1427.9 Section 1427.9... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Nonrecourse Cotton Loan and Loan Deficiency Payments § 1427.9 Classification of cotton. (a) All cotton tendered for loan and loan...

  13. 7 CFR 27.46 - Cotton withdrawn from storage.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Cotton withdrawn from storage. 27.46 Section 27.46... REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Cotton Class Certificates § 27.46 Cotton withdrawn from storage. The exchange inspection agency under the supervision or control...

  14. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature on demand by CCC but no later than May 31...

  15. 7 CFR 1205.342 - Certification of cotton importer organizations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Certification of cotton importer organizations. 1205... COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Certification of Cotton Producer Organization § 1205.342 Certification of cotton importer organizations. Any importer organization may...

  16. 7 CFR 1205.402 - Determination of Cotton Board membership.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Determination of Cotton Board membership. 1205.402... COTTON RESEARCH AND PROMOTION Members of Cotton Board § 1205.402 Determination of Cotton Board membership. (a) In determining whether any cotton-producing state is entitled to be represented by more than...

  17. 7 CFR 28.39 - Cotton reduced in grade.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Cotton reduced in grade. 28.39 Section 28.39... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Regulations Under the United States Cotton Standards Act Classification § 28.39 Cotton reduced in grade. If cotton be reduced in grade, by reason of the presence...

  18. 7 CFR 28.106 - Universal cotton standards.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Universal cotton standards. 28.106 Section 28.106... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Regulations Under the United States Cotton Standards Act Practical Forms of Cotton Standards § 28.106 Universal cotton standards. Whenever any of the official...

  19. 7 CFR 27.37 - Cotton reduced in grade.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Cotton reduced in grade. 27.37 Section 27.37... REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Classification and Micronaire Determinations § 27.37 Cotton reduced in grade. If cotton be reduced in grade, by reason of the presence...

  20. 7 CFR 1427.9 - Classification of cotton.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Classification of cotton. 1427.9 Section 1427.9... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Nonrecourse Cotton Loan and Loan Deficiency Payments § 1427.9 Classification of cotton. (a) All cotton tendered for loan and loan...

  1. 7 CFR 27.37 - Cotton reduced in grade.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Cotton reduced in grade. 27.37 Section 27.37... REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Classification and Micronaire Determinations § 27.37 Cotton reduced in grade. If cotton be reduced in grade, by reason of the presence...

  2. 7 CFR 27.46 - Cotton withdrawn from storage.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Cotton withdrawn from storage. 27.46 Section 27.46... REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Cotton Class Certificates § 27.46 Cotton withdrawn from storage. The exchange inspection agency under the supervision or control...

  3. 7 CFR 28.105 - Practical forms of cotton standards.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Practical forms of cotton standards. 28.105 Section 28... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Regulations Under the United States Cotton Standards Act Practical Forms of Cotton Standards § 28.105 Practical forms of cotton standards. (a) Practical forms of...

  4. 7 CFR 28.178 - Submission of cotton samples.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Submission of cotton samples. 28.178 Section 28.178... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Classification for Foreign Growth Cotton § 28.178 Submission of cotton samples. Samples of cotton submitted to a Classing Office for classification...

  5. 7 CFR 28.105 - Practical forms of cotton standards.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Practical forms of cotton standards. 28.105 Section 28... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Regulations Under the United States Cotton Standards Act Practical Forms of Cotton Standards § 28.105 Practical forms of cotton standards. (a) Practical forms of...

  6. 7 CFR 1427.165 - Eligible seed cotton.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Eligible seed cotton. 1427.165 Section 1427.165... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.165 Eligible seed cotton. (a) Seed cotton pledged as collateral for a loan must be tendered to CCC by...

  7. 7 CFR 1427.174 - Maturity of seed cotton loans.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Maturity of seed cotton loans. 1427.174 Section 1427..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Recourse Seed Cotton Loans § 1427.174 Maturity of seed cotton loans. Seed cotton loans mature on demand by CCC but no later than May 31...

  8. Cotton Square Morphology Offers New Insights into Host Plant Resistance to Cotton Fleahopper (Hemiptera: Miridae) in Upland Cotton.

    PubMed

    McLoud, Laura Ann; Hague, Steven; Knutson, Allen; Wayne Smith, C; Brewer, Michael

    2016-02-01

    Cotton fleahopper, Pseudatomoscelis seriatus (Reuter) (Hemiptera: Miridae), is a piercing-sucking pest of cotton (Gossypium hirsutum L.) that feeds preferentially on developing flower buds, called squares. Heavy infestations cause yield reductions that result from abscission of squares damaged by the cotton fleahopper feeding. Antixenosis, or nonpreference, has been reported as a mechanism of host plant resistance in cotton to cotton fleahopper. Square structure, particularly the placement of the reproductive tissues, and stylet penetration were investigated as factors that influence resistance to cotton fleahopper in cotton lines derived from crosses with Pilose, a cultigen of upland cotton resistant to cotton fleahopper, and backcrossed with high-yielding, susceptible lines. Ovary depth varied among the lines tested and was found to be a heritable trait that affected the ability of a fleahopper's feeding stylets to penetrate the reproductive tissues in the square and might influence preference. Behavioral assays suggested antixenosis as a mechanism of host plant resistance, and the trait conferring antixenosis was found to be heritable. Results suggest ovary depth plays a role in conferring resistance to cotton fleahopper and is an exploitable trait in resistance breeding. PMID:26475922

  9. Uptake and Transfer of a Bt Toxin by a Lepidoptera to Its Eggs and Effects on Its Offspring

    PubMed Central

    Paula, Débora Pires; Andow, David A.; Timbó, Renata Velozo; Sujii, Edison R.; Pires, Carmen S. S.; Fontes, Eliana M. G.

    2014-01-01

    Research on non-target effects of transgenic crop plants has focused primarily on bitrophic, tritrophic and indirect effects of entomotoxins from Bacillus thuringiensis, but little work has considered intergenerational transfer of Cry proteins. This work reports a lepidopteran (Chlosyne lacinia) taking up a Bt entomotoxin when exposed to sublethal or low concentrations, transferring the entomotoxin to eggs, and having adverse effects on the first filial generation (F1) offspring. Two bioassays were conducted using a sublethal concentration of toxin (100.0 ng/µl Cry1Ac) for adults and a concentration equal to the LC10 (2.0 ng/µl Cry1Ac) for larvae. Cry1Ac is the most common entomotoxin expressed in Bt cotton in Brazil. In the adult diet bioassay there was no adverse effect on the parental generation (P0) adults, but the F1 larvae had higher mortality and longer development time compared to F1 larvae of parents that did not ingest Cry1Ac. For the 3rd instar larvae, there was no measurable effect on the P0 larvae, pupae and adults, but the F1 larvae had higher mortality and longer development time. Using chemiluminescent Western Blot, Cry1Ac was detected in F1 eggs laid by P0 butterflies from both bioassays. Our study indicates that, at least for this species and these experimental conditions, a ∼65 kDa insecticidal protein can be taken up and transferred to descendants where it can increase mortality and development time. PMID:24747962

  10. Dispersal behavior of neonate European corn borer (Lepidoptera: Crambidae) on Bt corn.

    PubMed

    Razze, J M; Mason, C E

    2012-08-01

    European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae), has historically been a significant economically important insect pest of corn (Zea mays L.) in the United States and Canada. The development in the 1990s of genetically modified corn expressing genes derived from Bacillus thuringiensis (Bt) that encodes insecticidal crystalline (Cry) proteins has proven to be effective in controlling this insect as well as other corn pests. The purpose of this study was to assess the movement and dispersal behavior of neonate European corn borer on Bt corn. We examined differences in neonate European corn borer dispersal behavior for the first 4 h after eclosion in the field among a stacked pyramid (Cry1F X Cry1Ab X Cry34/35Ab1) Bt corn, a Cry1F Bt corn, and a non-Bt sweet corn; and in the laboratory among a Bt corn hybrid containing Cry1F, a hybrid containing Cry1Ab, a pyramid combining these two hybrids (Cry1F X Cry1Ab), and a non-Bt near isoline corn. In field experiments, we found that dispersal was significantly higher on Bt corn compared with sweet corn. In laboratory experiments, dispersal was significantly higher on Cry1Ab Bt corn and Cry1F X Cry1Ab Bt corn than on non-Bt near isoline corn. Results indicated that neonate dispersal may be significantly greater in Bt cornfields compared with non-Bt cornfields. The findings on dispersal behavior in this study will be useful in evaluating the efficacy of a blended seed refuge system for managing European corn borer resistance in Bt corn. PMID:22928300

  11. Measurement of B(t -> Wb)/B(t -> Wq)

    SciTech Connect

    Tecchio, Monica; /Michigan U.

    2004-12-01

    The authors measure the ratio R = B(t {yields} Wb)/B(t {yields} Wq) in top-quark decays at CDF. R is determined from the relative rates of identified b jets in t{bar t} decays reconstructed both in the lepton-plus-jets and dilepton final states. They obtain R > 0.62 at the 95% CL, consistent with Standard Model expectations.

  12. Cocoa/Cotton Comparative Genomics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With genome sequence from two members of the Malvaceae family recently made available, we are exploring syntenic relationships, gene content, and evolutionary trajectories between the cacao and cotton genomes. An assembly of cacao (Theobroma cacao) using Illumina and 454 sequence technology yielded ...

  13. Canopy temperature and cotton performance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Abstract The temperature of a cotton canopy is a useful indicator of both the metabolic state and water status of the crop. Recent advances in equipment have resulted in reductions in the cost and complexity of near continuous canopy temperature monitoring. Measurements on a seasonal timeframe at a ...

  14. Remote sensing for cotton farming

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Application of remote sensing technologies in agriculture began with the use of aerial photography to identify cotton root rot in the late 1920s. From then on, agricultural remote sensing has developed gradually until the introduction of precision farming technologies in the late 1980s and biotechno...

  15. COTTON STICKINESS MITIGATION BY BACTERIA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sugars deposited on lint by late season sucking insects can make cotton difficult to spin and difficult to market. This study evaluated a lacto bacillus strain that metabolizes insect sugars under low moisture conditions. Lint with known levels of stickiness was sprayed with water containing Lasil...

  16. New Low Gossypol Cotton Germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cultivated cotton and its wild relatives typically have glands on both the reproductive and vegetative parts of the plant. These glands contain compounds that are toxic to many pests and help protect the plant from tobacco budworms (TBW), bollworms (BW), plant bugs and possibly some diseases. Unfort...

  17. Future of Cotton in Nonwovens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although cotton offers several positive attributes, such as absorbency of liquids, dyeability, transportation and dissipation of moisture for wear comfort, static-freedom, sustainability, biodegradability and bioconsumability, and the like, its use in nonwoven products has been minimal. In order to ...

  18. Anthraquinone dyes for superhydrophobic cotton.

    PubMed

    Salabert, J; Sebastián, R M; Vallribera, A

    2015-09-28

    Water-repellent, self-cleaning and stain resistant textiles are of interest for industrial applications. Anthraquinone reactive dyes were covalently grafted onto cotton fabric surfaces obtaining bright colors with good wash-fastness properties and giving rise to breathable superhydrophobic textiles with self-cleaning properties. PMID:26265296

  19. Sources of heterosis in cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Historically, re-selection, pedigree, and mass selection breeding methods have been used to develop open-pollinated cultivars of Upland cotton (Gossypium hirsutum L.). Due to the predominance of these breeding methods, we hypothesize that modern cultivars, as opposed to obsolete cultivars, have accu...

  20. Alternative nitrogen sources for cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several alternative nitrogen (N) sources, rates of N, and amendments were evaluated at Prattville, Alabama, on cotton in 2008. Nitrogen rates reported are for sidedress application only. Dry urea produced the highest yield, averaging 1100 pounds lint per acre. Ammonia volatilization was measured fr...

  1. Sustainability of insect resistance management strategies for transgenic Bt corn.

    PubMed

    Glaser, John A; Matten, Sharlene R

    2003-12-01

    Increasing interest in the responsible management of technology in the industrial and agricultural sectors of the economy has been met thorough the development of broadly applicable tools to assess the "sustainability" of new technologies. An arena ripe for application of such analysis is the deployment of transgenic crops. The new transgenic pesticidal or plant-incorporated protectant (PIP) crops have seen widespread application in the United States based on the features of higher yield, lower applications of insecticides, and control of mycotoxin content. However, open rejection of these new crops in Europe and in other countries has been a surprising message and has limited their worldwide acceptance. The US Environmental Protection Agency's (USEPA) Office of Pesticide Programs (OPP) has worked on the development and analysis of insect resistance management (IRM) strategies and has mandated specific IRM requirements for Bacillus thuringiensis (Bt) crops since 1995 under the Food, Fungicide, Insecticide, and Rodenticide Act. Improvement of data quality and sustainability of IRM strategies have been targeted in an ongoing partnership between the USEPA Office of Research and Development and the Office of Pesticide Programs that will further enhance the agency's ability to develop sustainable insect resistance management strategies for transgenic field corn (Bt corn) producing B. thuringiensis (Bt) insecticidal proteins. PMID:14623043

  2. The impact of common smut(Ustilago maydis) on aflatoxin and fumonisin in transgenic Bt and non-Bt maize (Zea mays)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Corn infected with Ustilago maydis (common smut), produces galls that are valued food in certain cultures, but may be contaminated with mycotoxins. Field studies conducted in Elizabeth, Mississippi used near-isogenic Bt and non-Bt corn hybrids. The levels of aflatoxin and fumonisin were determined ...

  3. Potential Use of Proteinase Inhibitors, Avidin, and Other Bio-reagents for Synergizing Bt Performance and Delaying Resistance Development to Bt

    Technology Transfer Automated Retrieval System (TEKTRAN)

    After being ingested by target insects, the insecticidal proteins from Bacillus thuringiensis (Bt) need to go through a proteolytic process by insect midgut proteinases to become activated. At the same time, Bt can be hydrolyzed and degraded by midgut proteinases to become non-toxic to target insect...

  4. Detection methods for biotech cotton MON 15985 and MON 88913 by PCR.

    PubMed

    Lee, Seong-Hun; Kim, Jin-Kug; Yi, Bu-Young

    2007-05-01

    Plants derived through agricultural biotechnology, or genetically modified organisms (GMOs), may affect human health and ecological environment. A living GMO is also called a living modified organism (LMO). Biotech cotton is a GMO in food or feed and also an LMO in the environment. Recently, two varieties of biotech cotton, MON 15985 and MON 88913, were developed by Monsanto Co. The detection method is an essential element for the GMO labeling system or LMO management of biotech plants. In this paper, two primer pairs and probes were designed for specific amplification of 116 and 120 bp PCR products from MON 15985 and MON 88913, respectively, with no amplification from any other biotech cotton. Limits of detection of the qualitative method were all 0.05% for MON 15985 and MON 88913. The quantitative method was developed using a TaqMan real-time PCR. A synthetic plasmid, as a reference molecule, was constructed from a taxon-specific DNA sequence of cotton and two construct-specific DNA sequences of MON 15985 and MON 88913. The quantitative method was validated using six samples that contained levels of biotech cotton mixed with conventional cotton ranging from 0.1 to 10.0%. As a result, the biases from the true value and the relative deviations were all within the range of +/-20%. Limits of quantitation of the quantitative method were all 0.1%. Consequently, it is reported that the proposed detection methods were applicable for qualitative and quantitative analyses for biotech cotton MON 15985 and MON 88913. PMID:17402745

  5. Bt crops benefit natural enemies to control non-target pests

    PubMed Central

    Tian, Jun-Ce; Yao, Ju; Long, Li-Ping; Romeis, Jörg; Shelton, Anthony M.

    2015-01-01

    Crops producing insecticidal crystal (Cry) proteins from Bacillus thuringiensis (Bt) control important lepidopteran pests. However, pests such as aphids not susceptible to Cry proteins may require other integrated pest management (IPM) tactics, including biological control. We fed aphids on Bt and non-Bt plants and analyzed the Bt protein residue in aphids and compared the effects of Bt plants and a pyrethroid, lambda-cyhalothrin, on the performance of three natural enemies (predators: Coleomegilla maculata and Eupeodes americanus; parasitoid Aphidius colemani) of the green peach aphid, Myzus persicae. No Bt protein residues in aphids were detected and no significant differences were recorded in the performance of pyrethroid-resistant aphids that fed on Bt broccoli expressing Cry1Ab or Cry1C, or on non-Bt broccoli plants treated or not treated with the pyrethroid. This indicated the aphids were not affected by the Cry proteins or the pyrethroid, thus removing any effect of prey quality. Tri-trophic experiments demonstrated that no C. maculata and E. americanus survived consumption of pyrethroid-treated aphids and that ovipositional behavior of A. colemani was impaired when provided with pyrethroid-treated aphids. In contrast, natural enemies were not affected when fed aphids reared on Bt broccoli, thus demonstrating the safety of these Bt plants for IPM. PMID:26559133

  6. COMMERCIAL COTTON VARIETY SPINNING STUDY DESCRIPTIVE STATISTICS AND DISTRIBUTIONS OF COTTON FIBER AND YARN

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Cotton Quality Research Station (CQRS) of the USDA-ARS, located in Clemson, SC has completed a comprehensive study of the relationship of cotton fiber properties to the quality of spun yarn. The five year study, began in 2001, utilized commercial variety cotton grown, harvested and ginned in ...

  7. Commercial cotton variety spinning study descriptive statistics and distributions of cotton fiber and yarn.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Cotton Quality Research Station (CQRS) of the USDA-ARS, located in Clemson, SC, has completed a comprehensive study of the relationship of cotton fiber properties to the quality of spun yarn. The five year study, began in 2001, utilized commercial variety cotton grown, harvested and ginned in e...

  8. Evaluation of modern cotton harvest systems on irrigated cotton: Yarn quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of harvest methods (cotton picker vs. cotton stripper) on yarn quality from irrigated cotton harvested on the High Plains of Texas with modern equipment was measured using multiple cultivars from six sites over three years. Few differences were detected in carded yarn quality between har...

  9. Design and evaluation of a source sampling system for cotton harvesters - Seed cotton separation system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton producers in some states across the US cotton belt are facing increased regulatory pressure with regard to air quality permit compliance and reducing fugitive PM emissions. Little accurate emission factor data from cotton picking operations are available for use in the air pollution regulator...

  10. Ecological Misconceptions.

    ERIC Educational Resources Information Center

    Munson, Bruce H.

    1994-01-01

    Presents a summary of the research literature on students' ecological conceptions and the implications of misconceptions. Topics include food webs, ecological adaptation, carrying capacity, ecosystem, and niche. (Contains 35 references.) (MKR)

  11. Functional validation of cadherin as a receptor of Bt toxin Cry1Ac in Helicoverpa armigera utilizing the CRISPR/Cas9 system.

    PubMed

    Wang, Jing; Zhang, Haonan; Wang, Huidong; Zhao, Shan; Zuo, Yayun; Yang, Yihua; Wu, Yidong

    2016-09-01

    Cadherins have been identified as receptors of Bacillus thuringiensis (Bt) Cry1A toxins in several lepidopteran insects including the cotton bollworm, Helicoverpa armigera. Disruption of the cadherin gene HaCad has been genetically linked to resistance to Bt toxin Cry1Ac in H. armigera. By using the CRISPR/Cas9 genome editing system (Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated protein 9), HaCad from the Cry1Ac-susceptible SCD strain of H. armigera was successfully knocked out. A single positive CRISPR event with a frame shift deletion of 4 nucleotides was identified and made homozygous to create a knockout line named SCD-Cad. Western blotting confirmed that HaCad was no longer expressed in the SCD-Cad line while an intact HaCad of 210 kDa was present in the parental SCD strain. Insecticide bioassays were used to show that SCD-Cad exhibited 549-fold resistance to Cry1Ac compared with SCD, but no significant change in susceptibility to Cry2Ab. Our results not only provide strong reverse genetics evidence for HaCad as a functional receptor of Cry1Ac, but also demonstrate that the CRISPR/Cas9 technique can act as a powerful and efficient genome editing tool to study gene function in a global agricultural pest, H. armigera. PMID:27343383

  12. Backyard Ecology.

    ERIC Educational Resources Information Center

    Elser, Monica; Musheno, Birgit; Saltz, Charlene

    2003-01-01

    Describes the Ecology Explorers, the community education component of Arizona State University's Central Arizona Phoenix Long-Term Ecological Research project, which offers teacher internship programs that link university researchers, K-12 teachers, and students in studying urban ecology. Explains that student neighborhoods are dynamic ecosystems…

  13. Estimation of ovular fiber production in cotton

    SciTech Connect

    Van`t Hof, J.

    1998-09-01

    The present invention is a method for rendering cotton fiber cells that are post-anthesis and pre-harvest available for analysis of their physical properties. The method includes the steps of hydrolyzing cotton fiber cells and separating cotton fiber cells from cotton ovules thereby rendering the cells available for analysis. The analysis of the fiber cells is through any suitable means, e.g., visual inspection. Visual inspection of the cells can be accomplished by placing the cells under an instrument for detection, such as microscope or other means. 4 figs.

  14. Estimation of ovular fiber production in cotton

    DOEpatents

    Van't Hof, Jack

    1998-09-01

    The present invention is a method for rendering cotton fiber cells that are post-anthesis and pre-harvest available for analysis of their physical properties. The method includes the steps of hydrolyzing cotton fiber cells and separating cotton fiber cells from cotton ovules thereby rendering the cells available for analysis. The analysis of the fiber cells is through any suitable means, e.g., visual inspection. Visual inspection of the cells can be accomplished by placing the cells under an instrument for detection, such as microscope or other means.

  15. Cotton Fever: Does the Patient Know Best?

    PubMed

    Xie, Yingda; Pope, Bailey A; Hunter, Alan J

    2016-04-01

    Fever and leukocytosis have many possible etiologies in injection drug users. We present a case of a 22-year-old woman with fever and leukocytosis that were presumed secondary to cotton fever, a rarely recognized complication of injection drug use, after an extensive workup. Cotton fever is a benign, self-limited febrile syndrome characterized by fevers, leukocytosis, myalgias, nausea and vomiting, occurring in injection drug users who filter their drug suspensions through cotton balls. While this syndrome is commonly recognized amongst the injection drug user population, there is a paucity of data in the medical literature. We review the case presentation and available literature related to cotton fever. PMID:26105678

  16. Susceptibility of Anthonomus grandis (cotton boll weevil) and Spodoptera frugiperda (fall armyworm) to a cry1ia-type toxin from a Brazilian Bacillus thuringiensis strain.

    PubMed

    Grossi-de-Sa, Maria Fatima; Quezado de Magalhaes, Mariana; Silva, Marilia Santos; Silva, Shirley Margareth Buffon; Dias, Simoni Campos; Nakasu, Erich Yukio Tempel; Brunetta, Patricia Sanglard Felipe; Oliveira, Gustavo Ramos; Neto, Osmundo Brilhante de Oliveira; Sampaio de Oliveira, Raquel; Soares, Luis Henrique Barros; Ayub, Marco Antonio Zachia; Siqueira, Herbert Alvaro Abreu; Figueira, Edson L Z

    2007-09-30

    Different isolates of the soil bacterium Bacillus thuringiensis produce multiple crystal (Cry) proteins toxic to a variety of insects, nematodes and protozoans. These insecticidal Cry toxins are known to be active against specific insect orders, being harmless to mammals, birds, amphibians, and reptiles. Due to these characteristics, genes encoding several Cry toxins have been engineered in order to be expressed by a variety of crop plants to control insectpests. The cotton boll weevil, Anthonomus grandis, and the fall armyworm, Spodoptera frugiperda, are the major economically devastating pests of cotton crop in Brazil, causing severe losses, mainly due to their endophytic habit, which results in damages to the cotton boll and floral bud structures. A cry1Ia-type gene, designated cry1Ia12, was isolated and cloned from the Bt S811 strain. Nucleotide sequencing of the cry1Ia12 gene revealed an open reading frame of 2160 bp, encoding a protein of 719 amino acid residues in length, with a predicted molecular mass of 81 kDa. The amino acid sequence of Cry1Ia12 is 99% identical to the known Cry1Ia proteins and differs from them only in one or two amino acid residues positioned along the three domains involved in the insecticidal activity of the toxin. The recombinant Cry1Ia12 protein, corresponding to the cry1Ia12 gene expressed in Escherichia coli cells, showed moderate toxicity towards first instar larvae of both cotton boll weevil and fall armyworm. The highest concentration of the recombinant Cry1Ia12 tested to achieve the maximum toxicities against cotton boll weevil larvae and fall armyworm larvae were 230 microg/mL and 5 microg/mL, respectively. The herein demonstrated insecticidal activity of the recombinant Cry1Ia12 toxin against cotton boll weevil and fall armyworm larvae opens promising perspectives for the genetic engineering of cotton crop resistant to both these devastating pests in Brazil. PMID:17927912

  17. Modeling evolution of resistance of sugarcane borer (Lepidoptera: Crambidae) to transgenic Bt corn.

    PubMed

    Kang, J; Huang, F; Onstad, D W

    2014-08-01

    Diatraea saccharalis (F.) (Lepidoptera: Crambidae) is a target pest of transgenic corn expressing Bacillus thuringiensis (Bt) protein, and the first evidence of resistance by D. saccharalis to Cry1Ab corn was detected in a field population in northeast Louisiana in 2004. We used a model of population dynamics and genetics of D. saccharalis to 1) study the effect of interfield dispersal, the first date that larvae enter diapause for overwintering, toxin mortality, the proportion of non-Bt corn in the corn patch, and the area of a crop patch on Bt resistance evolution; and 2) to identify gaps in empirical knowledge for managing D. saccharalis resistance to Bt corn. Increasing, the proportion of corn refuge did not always improve the durability of Bt corn if the landscape also contained sugarcane, sorghum, or rice. In the landscape, which consisted of 90% corn area, 5% sorghum area, and 5% rice area, the durability of single-protein Bt corn was 40 yr when the proportion of corn refuge was 0.2 but 16 yr when the proportion of corn refuge was 0.5. The Bt resistance evolution was sensitive to a change (from Julian date 260 to 272) in the first date larvae enter diapause for overwintering and moth movement. In the landscapes with Bt corn, non-Bt corn, sugarcane, sorghum, and rice, the evolution of Bt resistance accelerated when larvae entered diapause for overwintering early. Intermediate rates of moth movement delayed evolution of resistance more than either extremely low or high rates. This study suggested that heterogeneity in the agrolandscapes may complicate the strategy for managing Bt resistance in D. saccharalis, and designing a Bt resistance management strategy for D. saccharalis is challenging because of a lack of empirical data about overwintering and moth movement. PMID:24914780

  18. [Effects of transgenic Bt rice on soil dissolved organic carbon and nitrogen contents and microbiological properties].

    PubMed

    Li, Xiu-Qiang; Chen, Fa-Jun; Liu, Man-Qiang; Hu, Feng

    2012-01-01

    A two-year field experiment (2009 and 2010) was conducted to evaluate the effects of three transgenic Bt rice lines (KMD, HH1, and BtSY63) and their non-Bt lines (XSD, MH63, and SY63) on soil dissolved organic carbon (DOC) and nitrogen (DON) and microbiological properties. All the measured indices changed significantly with sampling time. Comparing with their corresponding non-Bt lines, the test transgenic Bt lines had little effects on the soil DOC, DON, and microbial biomass nitrogen (MBN). The transgenic Bt lines had significant effects on the soil microbial biomass carbon (MBC), basal respiration (BR), and microbial metabolic quotient (qCO2) in certain periods of time in the first year, but no effects in the second year. Among the soils planted with the three non-Bt rice lines, no difference was observed in the DOC, DON, and microbiological properties, whereas in the soil planted with BtSY63, the MBC and BR were significantly higher, but the qCO2 was significantly lower, as compared with those in the soils planted with KMD and HH1. In sum, two years' planting transgenic Bt rice had little effects on the soil DOC, DON, and microbiological properties, but the differences of soil microbiological properties induced by the planting of different transgenic Bt rice lines were larger than those induced by the planting of different non-Bt lines, implying that long term monitoring would help to reveal the effects of transgenic Bt rice on the structure and function of soil ecosystem. PMID:22489485

  19. Densovirus Is a Mutualistic Symbiont of a Global Crop Pest (Helicoverpa armigera) and Protects against a Baculovirus and Bt Biopesticide

    PubMed Central

    Xu, Pengjun; Liu, Yongqiang; Graham, Robert I.; Wilson, Kenneth; Wu, Kongming

    2014-01-01

    Mutualistic associations between symbiotic bacteria and their hosts are common within insect systems. However, viruses are often considered as pathogens even though some have been reported to be beneficial to their hosts. Herein, we report a novel densovirus, Helicoverpa armigera densovirus-1 (HaDNV-1) that appears to be beneficial to its host. HaDNV-1 was found to be widespread in wild populations of H. armigera adults (>67% prevalence between 2008 and 2012). In wild larval populations, there was a clear negative interaction between HaDNV-1 and H. armigera nucleopolyhedrovirus (HaNPV), a baculovirus that is widely used as a biopesticide. Laboratory bioassays revealed that larvae hosting HaDNV-1 had significantly enhanced resistance to HaNPV (and lower viral loads), and that resistance to Bacillus thuringiensis (Bt) toxin was also higher at low doses. Laboratory assays indicated that the virus was mainly distributed in the fat body, and could be both horizontally- and vertically-transmitted, though the former occurred only at large challenge doses. Densovirus-positive individuals developed more quickly and had higher fecundity than uninfected insects. We found no evidence for a negative effect of HaDNV-1 infection on H. armigera fitness-related traits, strongly suggesting a mutualistic interaction between the cotton bollworm and its densovirus. PMID:25357125

  20. Decomposition rates and residue-colonizing microbial communities of Bacillus thuringiensis insecticidal protein Cry3Bb-expressing (Bt) and non-Bt corn hybrids in the field.

    PubMed

    Xue, Kai; Serohijos, Raquel C; Devare, Medha; Thies, Janice E

    2011-02-01

    Despite the rapid adoption of crops expressing the insecticidal Cry protein(s) from Bacillus thuringiensis (Bt), public concern continues to mount over the potential environmental impacts. Reduced residue decomposition rates and increased tissue lignin concentrations reported for some Bt corn hybrids have been highlighted recently as they may influence soil carbon dynamics. We assessed the effects of MON863 Bt corn, producing the Cry3Bb protein against the corn rootworm complex, on these aspects and associated decomposer communities by terminal restriction fragment length polymorphism (T-RFLP) analysis. Litterbags containing cobs, roots, or stalks plus leaves from Bt and unmodified corn with (non-Bt+I) or without (non-Bt) insecticide applied were placed on the soil surface and at a 10-cm depth in field plots planted with these crop treatments. The litterbags were recovered and analyzed after 3.5, 15.5, and 25 months. No significant effect of treatment (Bt, non-Bt, and non-Bt+I) was observed on initial tissue lignin concentrations, litter decomposition rate, or bacterial decomposer communities. The effect of treatment on fungal decomposer communities was minor, with only 1 of 16 comparisons yielding separation by treatment. Environmental factors (litterbag recovery year, litterbag placement, and plot history) led to significant differences for most measured variables. Combined, these results indicate that the differences detected were driven primarily by environmental factors rather than by any differences between the corn hybrids or the use of tefluthrin. We conclude that the Cry3Bb corn tested in this study is unlikely to affect carbon residence time or turnover in soils receiving these crop residues. PMID:21148693