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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.

  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

    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.

  4. 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

  5. Cotton bollworm resistance to Bt transgenic cotton: a case analysis.

    PubMed

    Liu, ChenXi; Li, YunHe; Gao, YuLin; Ning, ChangMing; Wu, KongMing

    2010-08-01

    Cotton bollworm (Helicoverpa armigera) is one of the most serious insect pests of cotton. Transgenic cotton expressing Cry toxins derived from a soil bacterium, Bacillus thuringiensis (Bt), has been produced to target this pest. Bt cotton has been widely planted around the world, and this has resulted in efficient control of bollworm populations with reduced use of synthetic insecticides. However, evolution of resistance by this pest threatens the continued success of Bt cotton. To date, no field populations of bollworm have evolved significant levels of resistance; however, several laboratory-selected Cry-resistant strains of H. armigera have been obtained, which suggests that bollworm has the capacity to evolve resistance to Bt. The development of resistance to Bt is of great concern, and there is a vast body of research in this area aimed at ensuring the continued success of Bt cotton. Here, we review studies on the evolution of Bt resistance in H. armigera, focusing on the biochemical and molecular basis of Bt resistance. We also discuss resistance management strategies, and monitoring programs implemented in China, Australia, and India.

  6. [Distribution of Bt protein in transgenic cotton soils].

    PubMed

    Fu, Qing-Ling; Chen, Su-Wan; Hu, Hong-Qing; Li, Zhen; Han, Xiao-Fang; Wang, Pu

    2011-06-01

    A pot experiment with red soil, yellow brown soil, and yellow cinnamon soil was conducted to detect the Bt protein content in rhizosphere and non-rhizosphere soils at different growth stages of transgenic Bt cotton and common cotton by using enzyme linked immunosorbent assay (ELISA). With the planting of transgenic Bt cotton, the Bt protein content in rhizosphere soil was significantly higher than that in non-rhizosphere soil; while in common cotton soils, there was no significant difference in the Bt protein content between rhizosphere soil and non-rhizosphere soil. At bud stage of transgenic Bt cotton, the Bt protein content in rhizosphere soil was in the order of yellow cinnamon soil > yellow brown soil > red soil, being 144% 121%, and 238% of that in common cotton rhizosphere soil; at florescence stage of transgenic Bt cotton, the Bt protein content in rhizosphere soil was in the order of yellow brown soil > yellow cinnamon soil > red soil, being 156% , 116% , and 197% of that in common cotton rhizosphere soil, respectively. Regardless of planting Bt cotton or common cotton, the Bt protein content in rhizosphere and non-rhizosphere soils had an initial increase with the growth of cotton, peaked at florescence stage, and then decreased. Throughout the whole cotton growth period, the Bt protein content in transgenic Bt cotton rhizosphere soil was higher than that in Bt cotton non-rhizosphere soil, and also, higher than that in common cotton rhizosphere soil, indicating that transgenic Bt cotton could release its Bt protein to rhizosphere soil.

  7. 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

    2015-06-01

    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.

  8. 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...

  9. 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…

  10. The halo effect: suppression of pink bollworm on non-Bt cotton by Bt cotton in China.

    PubMed

    Wan, Peng; Huang, Yunxin; 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.

  11. Helicoverpa zea and Bt cotton in the United States.

    PubMed

    Luttrell, Randall G; Jackson, Ryan E

    2012-01-01

    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-resistance prone Heliothis virescens (F.), tobacco budworm. Immature stages of the two species are difficult to separate in field environments. Tobacco budworm is very susceptible to most Bt toxins, and Bt cotton is considered to be "high dose." Bollworm is less susceptible to Bt toxins, and Bt cotton is not "high dose" for this pest. Bt cotton is routinely sprayed with traditional insecticides for bollworm control. Assays of bollworm field populations for susceptibility to Bt toxins expressed in Bt cotton have produced variable results since pre-deployment of Bt cottons in 1988 and 1992. Analyses of assay response trends have been used by others to suggest that field resistance has evolved to Bt toxins in bollworm, but disagreement exists on definitions of field resistance and confidence of variable assay results to project changes in susceptibility of field populations. Given historical variability in bollworm response to Bt toxins, erratic field control requiring supplemental insecticides since early field testing of Bt cottons, and dramatic increases in corn acreage in cotton growing areas of the Southern US, continued vigilance and concern for resistance evolution are warranted.

  12. 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...

  13. 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.

  14. 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.

  15. Impacts of Bt transgenic cotton on integrated pest management.

    PubMed

    Naranjo, Steven E

    2011-06-08

    Transgenic cotton that produced one or more insecticidal proteins of Bacillus thuringiensis (Bt) was planted on over 15 million hectares in 11 countries in 2009 and has contributed to a reduction of over 140 million kilograms of insecticide active ingredient between 1996 and 2008. As a highly selective form of host plant resistance, Bt cotton effectively controls a number of key lepidopteran pests and has become a cornerstone in overall integrated pest management (IPM). Bt cotton has led to large reductions in the abundance of targeted pests and benefited non-Bt cotton adopters and even producers of other crops affected by polyphagous target pests. Reductions in insecticide use have enhanced biological control, which has contributed to significant suppression of other key and sporadic pests in cotton. Although reductions in insecticide use in some regions have elevated the importance of several pest groups, most of these emerging problems can be effectively solved through an IPM approach.

  16. 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 ...

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

    PubMed

    Tetreau, Guillaume; Wang, Ran; Wang, Ping

    2017-03-08

    Development of resistance to the insecticidal toxins from Bacillus thuringiensis (Bt) in insects is the major threat to the continued success of transgenic Bt crops in agriculture. The fitness of Bt-resistant insects on Bt and non-Bt plants is a key parameter that determines the development of Bt resistance in insect populations. In this study, a comprehensive analysis of the fitness of Bt-resistant Trichoplusia ni strains on Bt cotton leaves was conducted. The Bt-resistant T. ni strains carried two genetically independent mechanisms of resistance to Bt toxins Cry1Ac and Cry2Ab. The effects of the two resistance mechanisms, individually and in combination, on the fitness of the T. ni strains on conventional non-Bt cotton and on transgenic Bt cotton leaves expressing a single-toxin Cry1Ac (Bollgard I) or two Bt toxins Cry1Ac and Cry2Ab (Bollgard II) were examined. The presence of Bt toxins in plants reduced the fitness of resistant insects, indicated by decreased net reproductive rate (R0 ) and intrinsic rate of increase (r). The reduction in fitness in resistant T. ni on Bollgard II leaves was greater than that on Bollgard I leaves. A 12.4-day asynchrony of adult emergence between the susceptible T. ni grown on non-Bt cotton leaves and the dual-toxin-resistant T. ni on Bollgard II leaves was observed. Therefore, multitoxin Bt plants not only reduce the probability for T. ni to develop resistance but also strongly reduce the fitness of resistant insects feeding on the plants.

  18. 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

  19. 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.

  20. 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.

  1. 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...

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

    PubMed

    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.

  3. 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

  4. Effects of transgenic Bt cotton on overwintering characteristics and survival of Helicoverpa armigera.

    PubMed

    Ouyang, Fang; Liu, Zhudong; Yin, Jin; Su, Jianwei; Wang, Chenzhu; Ge, Feng

    2011-01-01

    The effects of transgenic Bt cotton on the overwintering generation of the cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), are unknown. We hypothesized that a Bt cotton diet may adversely affect fitness of this generation and examined fresh weight, lipids, glycogens, low-molecular-weight sugars and SCPs (supercooling points) of pupae, as well as survival of larvae, diapausing pupae and adult emergence in comparison with controls. Field and laboratory experiments showed that larvae fed on Bt cotton had a decreased pupation rate, and fewer entered diapause and emerged as adults compared with larvae fed non-Bt cotton. Furthermore, larvae fed Bt cotton had reduced pupal weight, glycogen content and trehalose levels both in diapausing and in non-diapausing pupae, and only diapausing pupae had an increased SCP compared to controls. The SCPs of diapausing pupae reared on Bt cotton were significantly higher than those reared on non-Bt cotton. The trehalose levels of diapausing pupae reared on Bt cotton were significantly lower than those of larvae reared on non-Bt cotton. Thus, these results suggest that a Bt cotton diet weakens the preparedness of cotton bollworm for overwintering and reduces survival of the overwintering generation, which will in turn reduce the density of the first generation in the following year. Effects of transgenic Bt cotton on the overwintering generation of cotton bollworm appear to have significantly contributed to the suppression of cotton bollworm observed throughout northern China in the past decade.

  5. Early detection of field-evolved resistance to Bt cotton in China: cotton bollworm and pink bollworm.

    PubMed

    Tabashnik, Bruce E; Wu, Kongming; Wu, Yidong

    2012-07-01

    Transgenic crops producing Bacillus thuringiensis (Bt) toxins kill some major insect pests, but pests can evolve resistance and thereby reduce the effectiveness of such Bt crops. The main approach for slowing 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 cotton producing Bt toxin Cry1Ac, several 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. This strategy is designed for cotton bollworm (Helicoverpa armigera), which attacks many crops and is the primary target of Bt cotton in China, but it does not apply to pink bollworm (Pectinophora gossypiella), which feeds almost entirely on cotton in China. Here we review evidence of field-evolved resistance to Cry1Ac by cotton bollworm in northern China and by pink bollworm in the Yangtze River Valley of China. For both pests, results of laboratory diet bioassays reveal significantly decreased susceptibility of field populations to Cry1Ac, yet field control failures of Bt cotton have not been reported. The early detection of resistance summarized here may spur countermeasures such as planting Bt cotton that produces two or more distinct toxins, increased planting of non-Bt cotton, and integration of other management tactics together with Bt cotton.

  6. 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.

  7. 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

  8. Regulation of the seasonal population patterns of Helicoverpa armigera moths by Bt cotton planting.

    PubMed

    Gao, Yu-Lin; Feng, Hong-Qiang; Wu, Kong-Ming

    2010-08-01

    Transgenic cotton expressing the Bacillus thuringiensis (Bt) Cry1Ac toxin has been commercially cultivated in China since 1997, and by 2000 Bt cotton had almost completely replaced non-transgenic cotton cultivars. To evaluate the impact of Bt cotton planting on the seasonal population patterns of cotton bollworm, Helicoverpa armigera, the dynamics of H. armigera moths were monitored with light traps from four locations (Xiajin, Linqing and Dingtao of Shandong Province; Guantao of Hebei Province) in high Bt density region and five locations (Anci and Xinji of Hebei Province; Dancheng and Fengqiu of Henan Province; Gaomi of Shandong Province) in low Bt density region from 1996 to 2008. A negative correlation was found between moth densities of H. armigera and the planting years of Bt cotton in both high and low Bt density areas. These data indicate that the moth population density of H. armigera was reduced with the introduction of Bt cotton in northern China. Three generations of moths occurred between early June and late September in the cotton regions. Interestingly, second-generation moths decreased and seemed to vanish in recent years in high Bt density region, but this tendency was not found in low Bt density region. The data suggest that the planting of Bt cotton in high Bt density region was effective in controlling the population density of second-generation moths. Furthermore, the seasonal change of moth patterns associated with Bt cotton planting may regulate the regional occurrence and population development of this migratory insect.

  9. 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...

  10. [Effects of high temperature and humidity on leaf Bt protein expression of transgenic Bt cotton].

    PubMed

    Zhang, Xiang; Wang, Gui-Xia; Gu, Chao; Han, Yong; Xu, Ying-Fei; Chen, Yuan; Chen, De-Hua

    2012-11-01

    Different origins Bt cotton cultivars, including DP410B (conventional cultivar) and Daiza No. 1 (hybridized cultivar) from US and Sikang No. 1 (conventional cultivar) and Sikang No. 3 (hybridized cultivar) from China, were taken as the test materials to investigate the effects of high temperature (37 degrees C) and different humidity (50%, 70%, and 90%) on the leaf Bt protein expression of Bt cotton. At high temperature, temperature and humidity had no significant effects on the leaf Bt protein expression of the cultivars at peak squaring stage. At peak flowering stage, as compared with the control (25-30 degrees C and 60%-70% humidity), 37 degrees C and 50% humidity decreased the leaf Bt protein content of conventional cultivars significantly by 2.6%-3.0%. At peak bolling stage, compared with the control, 37 degrees C and 50% humidity decreased the leaf Bt protein content of DP410B, Sikang No. 1, and Sikang No. 3 significantly by 3.3%-5.8%. Among the four cultivars, DP410B and Daiza No. 1 had the highest leaf Bt protein content, while Sikang No. 1 had the lowest one.

  11. Supplemental Control with Diamides for Heliothines1 in Bt Cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Supplemental control of bollworm, Helicoverpa zea (Boddie), in Bt cotton with diamides is becoming more frequent, but there is little information on the net returns to growers. Seven locations were established across the MS Delta cropping region between 2014 and 2015 to examine the value of spraying...

  12. 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.

  13. 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...

  14. 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.

  15. 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...

  16. Widespread adoption of Bt cotton and insecticide decrease promotes biocontrol services.

    PubMed

    Lu, Yanhui; Wu, Kongming; Jiang, Yuying; Guo, Yuyuan; Desneux, Nicolas

    2012-07-19

    Over the past 16 years, vast plantings of transgenic crops producing insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) have helped to control several major insect pests and reduce the need for insecticide sprays. Because broad-spectrum insecticides kill arthropod natural enemies that provide biological control of pests, the decrease in use of insecticide sprays associated with Bt crops could enhance biocontrol services. However, this hypothesis has not been tested in terms of long-term landscape-level impacts. On the basis of data from 1990 to 2010 at 36 sites in six provinces of northern China, we show here a marked increase in abundance of three types of generalist arthropod predators (ladybirds, lacewings and spiders) and a decreased abundance of aphid pests associated with widespread adoption of Bt cotton and reduced insecticide sprays in this crop. We also found evidence that the predators might provide additional biocontrol services spilling over from Bt cotton fields onto neighbouring crops (maize, peanut and soybean). Our work extends results from general studies evaluating ecological effects of Bt crops by demonstrating that such crops can promote biocontrol services in agricultural landscapes.

  17. 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...

  18. Astylus atromaculatus (Coleoptera: Melyridae): abundance and role in pollen dispersal in Bt and non-Bt cotton in South Africa.

    PubMed

    Pierre, Jacqueline; Hofs, Jean-Luc

    2010-10-01

    In South Africa, modified Bt (Cry1 Ac) cotton cultivars and organic ones coexist. This raises the question of the risk of dissemination of genetically modified (GM) pollen to non-GM crops by visiting insects. We inventoried the flower-visiting insects in Bt and non-Bt cotton fields of the South African Highveld region and investigated their role in pollen dispersal. Their diversity and abundance varied slightly among sites, with Astylus atromaculatus as the predominant insect on both Bt and non-Bt cotton flowers. The other major flower-visiting species were Apis mellifera and solitary Apidae. No differences were found in the abundance of each taxum between Bt and non-Bt cotton except for Scoliidae and Nitidulidae, which were scarce overall (<0.5%) but more abundant on the non-Bt flowers in the central area of the field at one site. The pollen load on A. atromaculatus was as high as on Apis mellifera. Cage tests showed that A. atromaculatus can pollinate female cotton plants by transferring pollen from male donor plants. In the field, the flight range of this insect was generally short (25 m), but it can occasionally reach up to 200 m or even more. This study therefore highlights that A. atromaculatus, commonly regarded as a pest, could be an unexpected but efficient pollinator. Because its population density can be high, this species could mediate unwanted cotton pollen flow when distances between coexiting fields are not sufficient.

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

    PubMed

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

    2015-01-01

    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.

  20. Effects of transgenic Bt cotton on soil fertility and biology under field conditions in subtropical inceptisol.

    PubMed

    Singh, Raman Jeet; Ahlawat, I P S; Singh, Surender

    2013-01-01

    Although there is large-scale adoption of Bt cotton by the farmers because of immediate financial gain, there is concern that Bt crops release Bt toxins into the soil environment which reduces soil chemical and biological activities. However, the majorities of such studies were mainly performed under pot experiments, relatively little research has examined the direct and indirect effects of associated cover crop of peanut with fertilization by combined application of organic and inorganic sources of nitrogen under field conditions. We compared soil chemical and biological parameters of Bt cotton with pure crop of peanut to arrive on a valid conclusion. Significantly higher dehydrogenase enzyme activity and KMnO(4)-N content of soil were observed in Bt cotton with cover crop of peanut over pure Bt cotton followed by pure peanut at all the crop growth stages. However, higher microbial population was maintained by pure peanut over intercropped Bt cotton, but these differences were related to the presence of high amount of KMnO(4)-N content of soil. By growing cover crop of peanut between Bt cotton rows, bacteria, fungi, and actinomycetes population increased by 60%, 14%, and 10%, respectively, over Bt cotton alone. Bt cotton fertilized by combined application of urea and farm yard manure (FYM) maintained higher dehydrogenase enzyme activity, KMnO(4)-N content of soil and microbial population over urea alone. Significant positive correlations were observed for dry matter accumulation, dehydrogenase enzyme activity, KMnO(4)-N content, and microbial population of soil of Bt cotton, which indicates no harmful effects of Bt cotton on soil biological parameters and associated cover crop. Our results suggest that inclusion of cover crop of peanut and FYM in Bt cotton enhanced soil chemical and biological parameters which can mask any negative effect of the Bt toxin on microbial activity and thus on enzymatic activities.

  1. Field evaluation of Bt cotton crop impact on nontarget pests: cotton aphid and boll weevil.

    PubMed

    Sujii, E R; Togni, P H B; de A Ribeiro, P; de A Bernardes, T; Milane, P V G N; Paula, D P; Pires, C S S; Fontes, E M G

    2013-02-01

    Bt cotton plants expressing Cry1Ac protein have high specificity for the control of lepidopteran larvae. However, studies conducted in several countries have shown these plants have a differential impact on nontarget herbivores. The aim of this study was to compare the colonization rates and population abundance of the cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae) and the boll weevil, Anthonomus grandis Boheman (Coleoptera: Curculionidae), in plots of Bt (Nuopal) and non-Bt cotton (Delta Opal) in an experimental field in Brasilia, DF, Brazil. No difference was observed in the preference and colonization by winged aphids to plants from the two treatments. There was no significant difference in abundance of wingless aphids or in the production of winged aphids between treatments. Apparently, the parameters that control factors such as fecundity, survival, and dispersal were similar on both Bt and non-Bt plants. Monitoring of plants for coccinellids, a specialist predator of aphids, and ants that act on the dispersal of aphids among plants showed no significant difference between Bt and non-Bt plants, supporting the inference above. Regarding the effect on boll weevil, there was also no significant difference between treatments in the total number of fruiting structures attacked in each plot, the percentage of fruiting structures attacked per plant or on the number of weevils emerging from fruits with boll weevil damage from egg-laying, when damaged fruit samples were held in the laboratory. Based on these results, we conclude that there is no impact of Bt cotton crop expressing Cry1Ac on the nontarget herbivores tested under field conditions.

  2. Transgenic Bt Cotton Does Not Disrupt the Top-Down Forces Regulating the Cotton Aphid in Central China

    PubMed Central

    Yao, Yong-Sheng; Han, Peng; Niu, Chang-Ying; Dong, Yong-Cheng; Gao, Xi-Wu; Cui, Jin-Jie; Desneux, Nicolas

    2016-01-01

    Top-down force is referred to arthropod pest management delivered by the organisms from higher trophic levels. In the context of prevalent adoption of transgenic Bt crops that produce insecticidal Cry proteins derived from Bacillus thuringiensis (Bt), it still remains elusive whether the top-down forces are affected by the insect-resistant traits that introduced into the Bt crops. We explored how Bt cotton affect the strength of top-down forces via arthropod natural enemies in regulating a non-target pest species, the cotton aphid Aphis gossypii Glover, using a comparative approach (i.e. Bt cotton vs. conventional cotton) under field conditions. To determine top-down forces, we manipulated predation/parasitism exposure of the aphid to their natural enemies using exclusion cages. We found that the aphid population growth was strongly suppressed by the dominant natural enemies including Coccinellids, spiders and Aphidiines parasitoids. Coccinellids, spiders and the assemblage of other arthropod natural enemies (mainly lacewings and Hemipteran bugs) are similarly abundant in both plots, but with the parasitoid mummies less abundant in Bt cotton plots compared to the conventional cotton plots. However, the lower abundance of parasitoids in Bt cotton plots alone did not translate into differential top-down control on A. gossypii populations compared to conventional ones. Overall, the top-down forces were equally strong in both plots. We conclude that transgenic Bt cotton does not disrupt the top-down forces regulating the cotton aphid in central China. PMID:27870914

  3. Transgenic Bt Cotton Does Not Disrupt the Top-Down Forces Regulating the Cotton Aphid in Central China.

    PubMed

    Yao, Yong-Sheng; Han, Peng; Niu, Chang-Ying; Dong, Yong-Cheng; Gao, Xi-Wu; Cui, Jin-Jie; Desneux, Nicolas

    2016-01-01

    Top-down force is referred to arthropod pest management delivered by the organisms from higher trophic levels. In the context of prevalent adoption of transgenic Bt crops that produce insecticidal Cry proteins derived from Bacillus thuringiensis (Bt), it still remains elusive whether the top-down forces are affected by the insect-resistant traits that introduced into the Bt crops. We explored how Bt cotton affect the strength of top-down forces via arthropod natural enemies in regulating a non-target pest species, the cotton aphid Aphis gossypii Glover, using a comparative approach (i.e. Bt cotton vs. conventional cotton) under field conditions. To determine top-down forces, we manipulated predation/parasitism exposure of the aphid to their natural enemies using exclusion cages. We found that the aphid population growth was strongly suppressed by the dominant natural enemies including Coccinellids, spiders and Aphidiines parasitoids. Coccinellids, spiders and the assemblage of other arthropod natural enemies (mainly lacewings and Hemipteran bugs) are similarly abundant in both plots, but with the parasitoid mummies less abundant in Bt cotton plots compared to the conventional cotton plots. However, the lower abundance of parasitoids in Bt cotton plots alone did not translate into differential top-down control on A. gossypii populations compared to conventional ones. Overall, the top-down forces were equally strong in both plots. We conclude that transgenic Bt cotton does not disrupt the top-down forces regulating the cotton aphid in central China.

  4. Diminishing returns from increased percent Bt cotton: the case of pink bollworm.

    PubMed

    Huang, Yunxin; Wan, Peng; Zhang, Huannan; Huang, Minsong; Li, Zhaohua; Gould, Fred

    2013-01-01

    Regional suppression of pests by transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt) has been reported in several cropping systems, but little is known about the functional relationship between the ultimate pest population density and the pervasiveness of Bt crops. Here we address this issue by analyzing 16 years of field data on pink bollworm (Pectinophora gossypiella) population density and percentage of Bt cotton in 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 find that as the percent Bt cotton increased over the years, the cross-year growth rate of pink bollworm from the last generation of one year to the first generation of the next year decreased. However, as the percent Bt cotton increased, the within-year growth rate of pink bollworm from the first to last generation of the same year increased, with a slope approximately opposite to that of the cross-year rates. As a result, we did not find a statistically significant decline in the annual growth rate of pink bollworm as the percent Bt cotton increased over time. Consistent with the data, our modeling analyses predict that the regional average density of pink bollworm declines as the percent Bt cotton increases, but the higher the percent Bt cotton, the slower the decline in pest density. Specifically, we find that 95% Bt cotton is predicted to cause only 3% more reduction in larval density than 80% Bt cotton. The results here suggest that density dependence can act against the decline in pest density and diminish the net effects of Bt cotton on suppression of pink bollworm in the study region. The findings call for more studies of the interactions between pest density-dependence and Bt crops.

  5. Next-generation transgenic cotton: pyramiding RNAi and Bt counters insect resistance.

    PubMed

    Ni, Mi; Ma, Wei; Wang, Xiaofang; Gao, Meijing; Dai, Yan; Wei, Xiaoli; Zhang, Lei; Peng, Yonggang; Chen, Shuyuan; Ding, Lingyun; Tian, Yue; Li, Jie; Wang, Haiping; Wang, Xiaolin; Xu, Guowang; Guo, Wangzhen; Yang, Yihua; Wu, Yidong; Heuberger, Shannon; Tabashnik, Bruce E; Zhang, Tianzhen; Zhu, Zhen

    2017-02-15

    Transgenic crops producing insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) are extensively cultivated worldwide. To counter rapidly increasing pest resistance to crops that produce single Bt toxins, transgenic plant 'pyramids' producing two or more Bt toxins that kill the same pest have been widely adopted. However, cross-resistance and antagonism between Bt toxins limit the sustainability of this approach. Here we describe development and testing of the first pyramids of cotton combining protection from a Bt toxin and RNA interference (RNAi). We developed two types of transgenic cotton plants producing double-stranded RNA (dsRNA) from the global lepidopteran pest Helicoverpa armigera designed to interfere with its metabolism of juvenile hormone (JH). We focused on suppression of JH acid methyltransferase (JHAMT), which is crucial for JH synthesis, and JH-binding protein (JHBP), which transports JH to organs. In 2015 and 2016, we tested larvae from a Bt-resistant strain and a related susceptible strain of H. armigera on seven types of cotton: two controls, Bt cotton, two types of RNAi cotton (targeting JHAMT or JHBP) and two pyramids (Bt cotton plus each type of RNAi). Both types of RNAi cotton were effective against Bt-resistant insects. Bt cotton and RNAi acted independently against the susceptible strain. In computer simulations of conditions in northern China, where millions of farmers grow Bt cotton as well as abundant non-transgenic host plants of H. armigera, pyramided cotton combining a Bt toxin and RNAi substantially delayed resistance relative to using Bt cotton alone.

  6. Diminishing Returns from Increased Percent Bt Cotton: The Case of Pink Bollworm

    PubMed Central

    Zhang, Huannan; Huang, Minsong; Li, Zhaohua; Gould, Fred

    2013-01-01

    Regional suppression of pests by transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt) has been reported in several cropping systems, but little is known about the functional relationship between the ultimate pest population density and the pervasiveness of Bt crops. Here we address this issue by analyzing 16 years of field data on pink bollworm (Pectinophora gossypiella) population density and percentage of Bt cotton in 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 find that as the percent Bt cotton increased over the years, the cross-year growth rate of pink bollworm from the last generation of one year to the first generation of the next year decreased. However, as the percent Bt cotton increased, the within-year growth rate of pink bollworm from the first to last generation of the same year increased, with a slope approximately opposite to that of the cross-year rates. As a result, we did not find a statistically significant decline in the annual growth rate of pink bollworm as the percent Bt cotton increased over time. Consistent with the data, our modeling analyses predict that the regional average density of pink bollworm declines as the percent Bt cotton increases, but the higher the percent Bt cotton, the slower the decline in pest density. Specifically, we find that 95% Bt cotton is predicted to cause only 3% more reduction in larval density than 80% Bt cotton. The results here suggest that density dependence can act against the decline in pest density and diminish the net effects of Bt cotton on suppression of pink bollworm in the study region. The findings call for more studies of the interactions between pest density-dependence and Bt crops. PMID:23874678

  7. Bt cotton and farmer suicides in India: an evidence-based assessment.

    PubMed

    Gruère, Guillaume; Sengupta, Debdatta

    2011-01-01

    Bt cotton is accused of being responsible for an increase of farmer suicides in India. In this article, we provide a comprehensive review of evidence on Bt cotton and farmer suicides. Available data show no evidence of a 'resurgence' of farmer suicides. Moreover, Bt cotton technology has been very effective overall in India. Nevertheless, in specific districts and years, Bt cotton may have indirectly contributed to farmer indebtedness, leading to suicides, but its failure was mainly the result of the context or environment in which it was planted.

  8. 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.

  9. Effect of farm management practices in the Bt toxin production by Bt cotton: evidence from farm fields in China.

    PubMed

    Huang, Jikun; Mi, Jianwei; Chen, Ruijian; Su, Honghua; Wu, Kongming; Qiao, Fangbin; Hu, Ruifa

    2014-06-01

    Based on farm field plot level survey data and laboratory test, we examine the determinants of the expression of Bt toxin in China's Bt cotton production. The results show that the expression of Bt toxin differs significantly among varieties. Even for the same variety the expression of Bt toxin also varies substantially among villages and among farmers in the same village. Econometric analyses show that after controlling for the effects of varieties and locations (or villages), farm management, particular applications of phosphate and potash fertilizers, and manure, has significant positive effects on Bt toxin expression in farmer's fields. In contrast to previous studies which showed that nitrogen fertilizer has a positive impact on expression of Bt toxin, this study shows that nitrogen fertilizer has no significant impact on expression of Bt toxin in farmer's fields. On the other hand, the expression of Bt toxin has a positive relationship with phosphate fertilizer, potash fertilizer and manure application.

  10. Effectiveness of Microbial and Chemical Insecticides for Supplemental Control of Bollworm on Bt and non-Bt cottons

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Laboratory and field experiments were conducted to determine the effectiveness of microbial and chemical insecticides for supplemental control of bollworm (Helicoverpa zea Boddie) on non-Bt (DP1441®) and Bt (DP1321®) cottons. Neonate and 3rd instar larvae survival were evaluated on leaf tissue treat...

  11. 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

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

    PubMed

    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.

  13. Yield and fibre quality associated with cotton leaf curl disease of Bt-cotton in Punjab.

    PubMed

    Singh, Daljeet; Gill, J S; Gumber, R K; Singh, Ramandeep; Singh, Satnam

    2013-01-01

    Cotton leaf curl disease (CLCuD), caused by Gemini virus and transmitted through whitefly (Bemisia tabaci) is a serious problem in Northern India, affecting the productivity to a great extent. Depending upon the severity of infection in susceptible varieties, the disease can cause upto 90.0 % yield losses besides this, it also causes deterioration in fibre quality. The objective of the present study was to determine the effect of cotton leaf curl disease on seed cotton yield and fibre characters of two popular Bt-cotton hybrids in Punjab. The disease caused 52.7% reduction in number of bolls and 54.2 % in boll weight in Bt cotton hybrid RCH 134. Similarly, it reduced the fibre length from 29.1 to 26.2 mm (9.9%); fibre uniformity from 68.9 to 68.1% (1.1%); fibre strength from 29.1 to 26.9 g per texture (7.5%) and miconaire value from 5.2 to 5.0 g inch(-1) (3.8%). Similar results were reported in Bt cotton hybrid MRC 6304, where the disease reduced the boll number and boll weight by 46.1 and 43.4%, respectively. However, to the fibre quality was not much affected by varying level of disease severity. The studies clearly reflect the adverse impact of CLCuD on yield and fibre quality especially 2.5% span length. Thus suggesting the management of disease using integrated disease management strategies to avoid quantitative and qualitative losses.

  14. Resistance allele frequency to bt cotton in field populations of helicoverpa armigera (Lepidoptera: Noctuidae) in China.

    PubMed

    Liu, Fengyi; Xu, Zhiping; Chang, Juhua; Chen, Jin; Meng, Fengxia; Zhu, Yu Cheng; Shen, Jinliang

    2008-06-01

    Resistance evolution in target insects to Bacillus thurningiensis (Bt) cotton, Gossypium hirsutum L., is a main threat to Bt cotton technology. An increasing trend of population density of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) has been observed since 2001 in Qiuxian County (Hebei, China), where Bt cotton has been planted dominantly since 1998. This region was selected in 2006 and 2007 for estimating frequency of gene alleles conferring resistance to Bt cotton by screening the F1 progeny from single-pair cross between field-collected male and laboratory female of the Bt-resistant strain of H. armigera (F1 screen). F1 offspring from each single-pair line were screened for resistance alleles based on larval growth, development, and survival on Bt cotton leaves for 5 d. Two-year results indicated that approximately equal to 20% of field-collected males carried resistance alleles. The conservative estimate of the resistance allele frequency was 0.094 (95% CI, 0.044-0.145) for 2006 and 0.107 (95% CI, 0.055-0.159) for 2007. This is the first report of resistance allele frequency increase to such a high level in the field in China. Long-term adoption of Bt sprays, dominant planting of single-toxin-producing Bt cotton, and lack of conventional cotton refuge system might accelerate the resistance evolution in the region.

  15. 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.

  16. Oviposition on and mining in bolls of Bt and non-Bt cotton by resistant and susceptible pink bollworm (Lepidoptera: Gelechiidae).

    PubMed

    Liu, Yong-Biao; Tabashnik, Bruce E; Dennehy, Timothy J; Carrière, Yves; Sims, Maria A; Meyer, Susan K

    2002-02-01

    Transgenic cotton that produces insecticidal crystal protein Cry1Ac of Bacillus thuringiensis (Bt) has been effective in controlling pink bollworm, Pectinophora gossypiella (Saunders). We compared responses to bolls of Bt cotton and non-Bt cotton by adult females and neonates from susceptible and Cry1Ac-resistant strains of pink bollworm. In choice tests on caged cotton plants in the greenhouse, neither susceptible nor resistant females laid fewer eggs on Bt cotton bolls than on non-Bt cotton bolls, indicating that the Bt toxin did not deter oviposition. Multiple regression revealed that the number of eggs laid per boll was negatively associated with boll age and positively associated with boll diameter. Females also laid more eggs per boll on plants with more bolls. The distribution of eggs among bolls of Bt cotton and non-Bt cotton was clumped, indicating that boll quality rather than avoidance of previously laid eggs was a primary factor in oviposition preference. Parallel to the results from oviposition experiments, in laboratory no-choice tests with 10 neonates per boll, the number of entrance holes per boll did not differ between Bt cotton and non-Bt cotton for susceptible and resistant neonates. Also, like females, neonates preferred younger bolls and larger bolls. Thus, acceptance of bolls by females for oviposition and by neonates for mining was affected by boll age and diameter, but not by Bt toxin in bolls. The lack of discrimination between Bt and non-Bt cotton bolls by pink bollworm from susceptible and resistant strains indicates that oviposition and mining initiation are independent of susceptibility to Cry1Ac.

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

    PubMed

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

    2013-05-07

    The rapid adoption of genetically engineered (GE) plants that express insecticidal Cry proteins derived from Bacillus thuringiensis (Bt) has raised concerns about their potential impact on non-target organisms. This includes the possibility that non-target herbivores develop into pests. Although studies have now reported increased populations of non-target herbivores in Bt cotton, the underlying mechanisms are not fully understood. We propose that lack of herbivore-induced secondary metabolites in Bt cotton represents a mechanism that benefits non-target herbivores. We show that, because of effective suppression of Bt-sensitive lepidopteran herbivores, Bt cotton contains reduced levels of induced terpenoids. We also show that changes in the overall level of these defensive secondary metabolites are associated with improved performance of a Bt-insensitive herbivore, the cotton aphid, under glasshouse conditions. These effects, however, were not as clearly evident under field conditions as aphid populations were not correlated with the amount of terpenoids measured in the plants. Nevertheless, increased aphid numbers were visible in Bt cotton compared with non-Bt cotton on some sampling dates. Identification of this mechanism increases our understanding of how insect-resistant crops impact herbivore communities and helps underpin the sustainable use of GE varieties.

  18. Oviposition site selection and survival of susceptible and resistant larvae of Helicoverpa armigera (Lepidoptera: Noctuidae) on Bt and non-Bt cotton.

    PubMed

    Luong, T T A; Downes, S J; Cribb, B; Perkins, L E; Zalucki, M P

    2016-12-01

    In Australia Bt cotton has been planted since 1996, and has greatly improved the control of its key target Helicoverpa armigera (Hübner). There is no strong evidence that genetically modified cotton has been selected for significant physiological resistance to Bt toxin in field populations. There are many possible explanations for the lack of apparent selection that range from high compliance with the resistance management strategy for this technology to a lack of behavioral preference in key traits such as oviposition that could favor survival. To date most experiments that test oviposition of H. armigera on Bt cotton vs. conventional cotton have been done with susceptible moths. We determine the oviposition preference of a field isolated Bt resistant line of H. armigera and a susceptible counterpart when given a choice of non-Bt cotton and Bt-cotton with the same genetic background, and test whether there is any relationship between oviposition site selection (different plant structures) and the survival of the first instar larvae. Within cotton plants, our experiments consistently showed that both resistant and susceptible moths did not choose plants or plant parts that were less toxic in terms of Bt toxin on which to lay eggs. There was one exception in that susceptible moths were more likely to lay eggs on squares of Bt cotton plants than squares of non-Bt cotton. As expected, the mortality of susceptible H. armigera neonates was significantly higher on structures of Bt cotton plants than on those structures of conventional cotton, and survival was greater on flowers than on other structures of Bt cotton. This confirms opportunities for selection for resistance, and demonstrates no advantage in this respect to carrying resistance genes that might overcome the Bt toxins.

  19. Leaf surface factors of transgenic Bt cotton associated with the feeding behaviors of cotton aphids: a case study on non-target effects.

    PubMed

    Xue, Kun; Deng, Su; Wang, RongJiang; Yan, FengMing; Xu, ChongRen

    2008-02-01

    The present paper reports case study results of the risk assessment of transgenic Bt cotton on a non-target pest, cotton aphid, Aphis gossypii. Several types of techniques, i.e., electrical penetration graph (EPG), light and electron microscopy, bioassays and chemical analysis, were applied to investigate physical and chemical leaf factors of 2 transgenic Bt cotton lines (GK12 and GK19) and their parental non-Bt cotton line (Simian3) associated with searching and feeding behaviors of cotton aphids on leaves or leaf extracts of cotton plants. EPG results showed that there were some differences among behaviors of cotton aphids on 2 Bt cotton and 1 non-Bt cotton lines. Cotton aphids performed similarly to leaf surface extracts from 3 cotton lines; and leaf surface chemicals, mainly volatiles and waxes, were almost identical in the components and concentrations among the cotton lines. However, three cotton lines were quite different from each other in the densities of certain kinds of covering trichomes. Therefore, the relationships between the physical characteristics and the searching behaviors of cotton aphids on the three cotton lines were constructed as the regression equations. Glandular trichomes and covering trichomes with 5 branches influenced the cotton aphids' searching behaviors effectively; and other trichomes with other branches affected aphids in varying ways. These results demonstrated that leaf surface physical factors of transgenic Bt cotton lines different from their parental non-Bt line could affect the penetration behaviors of non-target cotton aphids. Cotton aphids penetrate and feed more easily on two Bt cotton lines than on the non-Bt cotton line.

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

    PubMed

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

    2015-05-07

    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.

  1. 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

  2. Effects of Soil Salinity on the Expression of Bt Toxin (Cry1Ac) and the Control Efficiency of Helicoverpa armigera in Field-Grown Transgenic Bt Cotton

    PubMed Central

    Luo, Jun-Yu; Zhang, Shuai; Peng, Jun; Zhu, Xiang-Zhen; Lv, Li-Min; Wang, Chun-Yi; Li, Chun-Hua; Zhou, Zhi-Guo; Cui, Jin-Jie

    2017-01-01

    An increasing area of transgenic Bacillus thuringiensis (Bt) cotton is being planted in saline-alkaline soil in China. The Bt protein level in transgenic cotton plants and its control efficiency can be affected by abiotic stress, including high temperature, water deficiency and other factors. However, how soil salinity affects the expression of Bt protein, thus influencing the control efficiency of Bt cotton against the cotton bollworm (CBW) Helicoverpa armigera (Hübner) in the field, is poorly understood. Our objective in the present study was to investigate the effects of soil salinity on the expression of Bt toxin (Cry1Ac) and the control efficiency of Helicoverpa armigera in field-grown transgenic Bt cotton using three natural saline levels (1.15 dS m-1 [low soil-salinity], 6.00 dS m-1 [medium soil-salinity] and 11.46 dS m-1 [high soil-salinity]). We found that the Bt protein content in the transgenic Bt cotton leaves and the insecticidal activity of Bt cotton against CBW decreased with the increasing soil salinity in laboratory experiments during the growing season. The Bt protein content of Bt cotton leaves in the laboratory were negatively correlated with the salinity level. The CBW populations were highest on the Bt cotton grown in medium-salinity soil instead of the high-salinity soil in field conditions. A possible mechanism may be that the relatively high-salinity soil changed the plant nutritional quality or other plant defensive traits. The results from this study may help to identify more appropriate practices to control CBW in Bt cotton fields with different soil salinity levels. PMID:28099508

  3. Effects of Soil Salinity on the Expression of Bt Toxin (Cry1Ac) and the Control Efficiency of Helicoverpa armigera in Field-Grown Transgenic Bt Cotton.

    PubMed

    Luo, Jun-Yu; Zhang, Shuai; Peng, Jun; Zhu, Xiang-Zhen; Lv, Li-Min; Wang, Chun-Yi; Li, Chun-Hua; Zhou, Zhi-Guo; Cui, Jin-Jie

    2017-01-01

    An increasing area of transgenic Bacillus thuringiensis (Bt) cotton is being planted in saline-alkaline soil in China. The Bt protein level in transgenic cotton plants and its control efficiency can be affected by abiotic stress, including high temperature, water deficiency and other factors. However, how soil salinity affects the expression of Bt protein, thus influencing the control efficiency of Bt cotton against the cotton bollworm (CBW) Helicoverpa armigera (Hübner) in the field, is poorly understood. Our objective in the present study was to investigate the effects of soil salinity on the expression of Bt toxin (Cry1Ac) and the control efficiency of Helicoverpa armigera in field-grown transgenic Bt cotton using three natural saline levels (1.15 dS m-1 [low soil-salinity], 6.00 dS m-1 [medium soil-salinity] and 11.46 dS m-1 [high soil-salinity]). We found that the Bt protein content in the transgenic Bt cotton leaves and the insecticidal activity of Bt cotton against CBW decreased with the increasing soil salinity in laboratory experiments during the growing season. The Bt protein content of Bt cotton leaves in the laboratory were negatively correlated with the salinity level. The CBW populations were highest on the Bt cotton grown in medium-salinity soil instead of the high-salinity soil in field conditions. A possible mechanism may be that the relatively high-salinity soil changed the plant nutritional quality or other plant defensive traits. The results from this study may help to identify more appropriate practices to control CBW in Bt cotton fields with different soil salinity levels.

  4. Sustained susceptibility of pink bollworm to Bt cotton in the United States.

    PubMed

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

    2012-01-01

    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 producing Bt toxin Cry1Ac in several countries for more than a decade. In China, the frequency of resistance to Cry1Ac has increased, but control failures have not been reported. In western India, pink bollworm resistance to Cry1Ac has caused widespread control failures of Bt cotton. By contrast, in the state of Arizona in the southwestern United States, monitoring data from bioassays and DNA screening demonstrate sustained susceptibility to Cry1Ac for 16 y. From 1996-2005, the main factors that delayed resistance in Arizona appear to be abundant refuges of non-Bt cotton, recessive inheritance of resistance, fitness costs associated with resistance and incomplete resistance. From 2006-2011, refuge abundance was greatly reduced in Arizona, while mass releases of sterile pink bollworm moths were made to delay resistance as part of a multi-tactic eradication program. Sustained susceptibility of pink bollworm to Bt cotton in Arizona has provided a cornerstone for the pink bollworm eradication program and for integrated pest management in cotton. Reduced insecticide use against pink bollworm and other cotton pests has yielded economic benefits for growers, as well as broad environmental and health benefits. We encourage increased efforts to combine Bt crops with other tactics in integrated pest management programs.

  5. Effects of Resistance to Bt Cotton on Diapause in the Pink Bollworm, Pectinophora gossypiella

    PubMed Central

    Carrière, Yves; Ellers-Kirk, Christa; Biggs, Robert W.; Sims, Maria A.; Dennehy, Timothy J.; Tabashnik, Bruce E.

    2007-01-01

    Fitness costs associated with resistance to Bacillus thuringiensis (Bt) crops are expected to delay the evolution of resistance. In a previous study where pink bollworm, Pectinophora gossypiella (Lepidoptera: Gelechiidae), larvae overwintered in outdoor insectaries, individuals from Bt-resistant strains had lower survival than individuals from Bt-susceptible strains or F1 progeny from crosses between resistant and susceptible adults. To investigate the physiological basis of such recessive cost, diapause duration was experimentally manipulated in the laboratory. Compared to a Bt-susceptible strain and F1 progeny, we hypothesized that Bt-resistant strains could exhibit a lower propensity or intensity of diapause, faster weight loss during overwintering, lower initial weight of diapausing larvae, and reduced longevity of moths emerging from diapause. Results were as expected for initial weight of diapausing larvae and longevity of overwintered male moths or female moths remaining in diapause for a short period. However, a higher diapause induction and intensity and slower weight loss occurred in F1 progeny and Bt-resistant strains than in a Bt-susceptible strain. Moreover, F1 progeny had greater overwintering survival than the Bt-resistant and Bt-susceptible strains, and F1 female moths had the greatest longevity after sustaining long diapausing periods. All of these unexpected results may be explained by pleiotropic effects of resistance to Bt cotton that increased the strength of diapause in the F1 progeny and Bt-resistant strains. Incomplete resistance was reflected in disadvantages suffered by Bt-resistant individuals feeding on a Bt diet instead of a non-Bt diet, including lower diapause propensity, lower diapause intensity and reduced longevity of overwintered male moths. While this study suggests that the evolution of resistance to Bt cotton and feeding on a Bt diet in Bt-resistant individuals have pervasive effects on several traits associated with diapause

  6. 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

  7. 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.

  8. 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

  9. [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.

  10. 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...

  11. 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

    2016-04-14

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

  12. 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

  13. Inheritance of transgenes in transgenic Bt lines resistance to Helicoerpa armigera in upland cotton.

    PubMed

    Zhang, Baolong; Guo, Wangzhen; Zhang, Tianzhen

    2013-01-01

    Six transgenic Bt cotton cultivars (lines) including GKsu12, GK19, MR1, GK5, 109B, and SGK1 are highly resistant to bollworm from the seedling to boll-setting stages in bioassays with detached cotton leaves, though there are differences in resistant level and Bt toxin content in these transgenic cottons. Genetics analysis reveals that the resistance to Helicoverpa armigera in these six transgenic Bt cotton cultivars (lines) are controlled by one pair of dominant genes. Allelic tests further demonstrate some populations are in Mendel segregation for two nonallelic genes, i.e., the inserted Bt gene in GKsu12 is nonallelic to that of SGK1, GK5, 109B, and GK19 and Bt genes in GK19 and SGK1 are likely inserted in the same or in close proximity (genetically closely linked), while some F(2) produce abnormal segregation patterns, with a segregation of resistance to Helicoerpa armigera vary between 15:1 and 3:1, though their Bt segregation fit into 15:1 by PCR analysis, suggesting Bt gene silence in these populations. Two genes silence may occur in these populations due to the homologous sequence by crossing since the silenced individuals accounted for 1/16 of the F(2) populations for allelic test. To those silenced populations, one of their parents all showed high resistance to bollworm.

  14. 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

    2015-11-12

    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.

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

    PubMed Central

    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. Bt cotton and employment effects for female agricultural laborers in Pakistan.

    PubMed

    Kouser, Shahzad; Abedullah; Qaim, Matin

    2017-01-25

    The literature about economic and social impacts of Bt cotton adoption on farm households in developing countries is growing. Yet, there is still uncertainty about wider implications of this technology for rural development, including effects for landless rural laborers. Bt-related yield advantages may lead to intensified production and higher demand for labor. Building on farm survey data collected in Pakistan and using double-hurdle regression models, we analyze employment effects of Bt cotton adoption. Model estimates show that Bt adoption has increased the demand for hired labor by 55%. Manual harvesting, which is common in Pakistan, is a labor-intensive activity primarily carried out by female laborers. Accordingly, gender disaggregation shows that the employment-generating effects are particularly strong for women, who often belong to the most disadvantaged groups of rural societies. These results suggest that Bt technology can contribute to additional employment income for the poor and to more equitable rural development.

  17. 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...

  18. 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

  19. 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.

  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.

  1. Temporal allocation of metabolic tolerance to transgenic Bt cotton in beet armyworm, Spodoptera exigua (Hübner).

    PubMed

    Guo, JianYing; Wu, Gang; Wan, FangHao

    2011-02-01

    Digestive and detoxification enzyme activity and nutrient composition were examined in the body of fourth instar beet armyworms, Spodoptera exigua (Hübner), fed on transgenic Bacillus thuringiensis (Bt) and non-Bt cotton for different time periods. Nutrient composition and specific enzyme activities differed significantly between the S. exigua fed Bt vs. non-Bt cotton. At 1, 6 and 24 h, free fatty acid and glucose levels were significantly lower in S. exigua fed on Bt cotton than those fed on non-Bt cotton. S. exigua fed on Bt cotton had significantly higher trypsin and total superoxide dismutase (T-SOD) activities and significantly lower lipase, carboxylesterase and acetylcholinesterase activities than non-Bt fed worms for all feeding time periods. Differences were also observed among feeding times within each cotton variety group. Significantly lower free fatty acid and total amino acid were observed in S. exigua fed on Bt cotton for 24 h than in those fed for 1 h. Significantly lower activities of lipase and trypsin were detected in S. exigua fed on Bt cotton for 24 h than those for 1 and 4 h. However, carboxylesterase and acetylcholinesterase activities in S. exigua fed on Bt cotton for 24 h were significantly higher than those for 1, 4 and 6 h. The interaction between cotton variety and feeding time significantly affected the activities of lipase, trypsin, acetylcholinesterase and T-SOD enzymes in S. exigua. Measuring the temporal allocation of protection and detoxification enzyme activities in the body of S. exigua in response to B. thuringiensis can provide a meaningful evaluation on the metabolic tolerance of herbivorous insects under the continuous selection pressure of a toxic protein.

  2. 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...

  3. Population dynamics of Spodoptera litura (Lepidoptera: Noctuidae) on Bt cotton in the Yangtze River Valley of China.

    PubMed

    Wan, Peng; Wu, Kongming; Huang, Minsong; Yu, Dazhao; Wu, Jinping

    2008-08-01

    Genetically modified cotton that produces a crystalline protein from Bacillus thuringiensis subsp. kurstaki (Berliner) (Bt) has been widely deployed to manage lepidopteran insect pests in cotton growing areas worldwide. However, susceptibility of different insect species to Bt protein varies, which may affect lepidopteran pest populations in the field. Studies on effects of two transgenic cotton lines (BG1560 and GK19) carrying a Cry1A gene on common cutworm Spodoptera litura F. (Lepidoptera: Noctuidae), were conducted during 2002-2005 in the cotton planting region of the Yangtze River valley of China. Results showed that common cutworm larvae had low susceptibility to Bt cotton. There was no significant difference in larval population densities in conventional and Bt cotton fields. However, the larval populations of the insect on conventional plants treated with chemical insecticides for control of target pest of Bt cotton were significantly lower than that in Bt cotton fields. These results indicated that the common cutworm was the potential to become a major and alarming pest in Bt cotton fields, and therefore efforts to develop an effective alternative management strategy are needed.

  4. Genetic diversity analysis of Bt cotton genotypes in Pakistan using simple sequence repeat markers.

    PubMed

    Ullah, I; Iram, A; Iqbal, M Z; Nawaz, M; Hasni, S M; Jamil, S

    2012-03-14

    The popularity of genetically modified insect resistant (Bt) cotton has promoted large scale monocultures, which is thought to worsen the problem of crop genetic homogeneity. Information on genetic diversity among Bt cotton varieties is lacking. We evaluated genetic divergence among 19 Bt cotton genotypes using simple sequence repeat (SSR) markers. Thirty-seven of 104 surveyed primers were found informative. Fifty-two primers selected on the basis of reported intra-hirsutum polymorphism in a cotton marker database showed a high degree of polymorphism, 56% compared to 13% for randomly selected primers. A total of 177 loci were amplified, with an average of 1.57 loci per primer, generating 38 markers. The amplicons ranged in size from 98 to 256 bp. The genetic similarities among the 19 genotypes ranged from 0.902 to 0.982, with an average of 0.947, revealing a lack of diversity. Similarities among genotypes from public sector organizations were higher than genotypes developed by private companies. Hybrids were found to be more distant compared to commercial cultivars and advanced breeding lines. Cluster analysis grouped the 19 Bt cotton genotypes into three major clusters and two independent entries. Cultivars IR-3701, Ali Akbar-802 and advanced breeding line VH-259 grouped in subcluster B2, with very narrow genetic distances despite dissimilar parentage. We found a very high level of similarity among Pakistani-bred Bt cotton varieties, which means that genetically diverse recurrent parents should be included to enhance genetic diversity. The intra-hirsutum polymorphic SSRs were found to be highly informative for molecular genetic diversity studies in these cotton varieties.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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...

  10. Transgenic Bacillus thuringiensis (Bt) cotton (Gossypium hirsutum) allomone response to cotton aphid, Aphis gossypii, in a closed-dynamics CO(2) chamber (CDCC).

    PubMed

    Wu, Gang; Chen, Fa Jun; Ge, Feng; Sun, Yu-Cheng

    2007-11-01

    Allocation of allomones of transgenic Bacillus thuringiensis Gossypium hirsutum (Bt cotton) (cv. GK-12) and non-Bt-transgenic cotton (cv. Simian-3) grown in elevated CO(2) in response to infestation by cotton aphid, Aphis gossypii Glover, was studied in a closed-dynamics CO(2) chamber. Significant increases in foliar condensed tannin and carbon/nitrogen ratio for GK-12 and Simian-3 were observed in elevated CO(2) relative to ambient CO(2,) as partially supported by the carbon nutrient balance hypothesis, owing to limiting nitrogen and excess carbon in cotton plants in response to elevated CO(2). The CO(2) level significantly influenced the foliar nutrients and allomones in the cotton plants. Aphid infestation significantly affected foliar nitrogen and allomone compounds in the cotton plants. Allomone allocation patterns in transgenic Bt cotton infested by A. gossypii may have broader implications across a range of plant and herbivorous insects as CO(2) continues to rise.

  11. Effects of root exudates of bivalent transgenic cotton (Bt+CpTI) plants on antioxidant proteins and growth of conventional cotton (Xinluhan 33).

    PubMed

    Wu, Hong-Sheng; Shi, Xue; Li, Ji; Wu, Tian-Yu; Ren, Qian-Qi; Zhang, Zhen-Hua; Wang, Ming-Yan; Shang, Xiao-Xia; Liu, Yan; Xiao, Song-Hua

    2016-01-01

    A greenhouse experiment was conducted to assess the adverse impact of transgenic cotton on ecosystem and environment via effect of transgenic Bt+CpTI cotton root exudates on growth and antioxidant activity of conventional parental cotton. Results showed elevated reductive and oxidative species activities in the leaves of conventional parental cotton seedlings treated with varying concentrations of transgenic cotton root exudates. Compared to control, 14.9% to 39.9% increase in catalase, 8.8% to 114% increase in for peroxidase, 21.3% to 59.7% increase in phenylalanine ammonia-lyase and 5.8 to 19.5 fold in ascorbate specific peroxidase was observed. However, biomass and height of conventional cotton seedlings were not affected by any concentration of transgenic cotton root exudates. These results suggested that cultivation of transgenic Bt+CpTI cotton plants poses little risk to conventional parental cotton based on their root interactions.

  12. 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.

  13. Successes and challenges of managing resistance in Helicoverpa armigera to Bt cotton in Australia.

    PubMed

    Downes, Sharon; Mahon, Rod

    2012-01-01

    Bt cotton has been gradually released and adopted by Australian growers since 1996. It was initially deployed in Australia primarily to control the polyphagous pest Helicoverpa armigera (Hübner), which in the 1990s became increasingly difficult to control due to widespread resistance to synthetic chemical insecticides. Bt-cotton has become a key tool in a program of integrated pest management for the production system that reduces pesticide dependence and the problems associated with its use. Herein we overview the deployment of Bt cotton in Australia including its performance and the approaches used to prolong the evolution of resistance to it by H. armigera. An integral component of this approach is monitoring resistance in this pest. We outline resistance screening methods, as well as the characteristics of resistant strains of H. armigera that have been isolated from field populations, or selected in the laboratory. We then highlight the successes and challenges for Bt cotton in Australia by way of discussing adaptive resistance management in light of potential changes in resistance.

  14. 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 ...

  15. 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...

  16. 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...

  17. Bt-transgenic cotton is more sensitive to CeO₂ nanoparticles than its parental non-transgenic cotton.

    PubMed

    Li, Xuguang; Gui, Xin; Rui, Yukui; Ji, Weikang; Van Nhan, Le; Yu, Zihan; Peng, Shengnan

    2014-06-15

    Because genetically modified crops are developing widely in the world while nanoparticles (NPs) are being synthesized and applied in various fields, they will have many opportunities for interactions in the future. The effects of NPs on genetically modified crops therefore require investigation. In the present study, CeO2 NPs were revealed to have toxic effects on root biomass of Bt 29317 at 100 and 500 mg L(-1), but had no toxic effects on Jihe 321. Besides, we also studied the effects of CeO2 NPs on nutrient element uptake in transgenic cotton, and found that contents of most nutrient elements (Fe, Ca, Mg, Zn and Na) in roots of Bt 29317 were affected at lower NP concentrations (100 mg L(-1)) compared with Jihe 321. In addition, ICP-MS analysis revealed that CeO2 NPs were more heavily adsorbed by roots of Bt 29317 than Jihe 321, whereas fewer CeO2 NPs were transported from roots to shoots of Bt 29317 than its non-transgenic counterpart. These data confirm that Bt 29317 is more sensitive to CeO2 NPs than its parental non-transgenic cotton, indicating that nanomaterials are potentially more detrimental to transgenic plants than conventional ones.

  18. 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

  19. Effect of pyramiding Bt and CpTI genes on resistance of cotton to Helicoverpa armigera (Lepidoptera: Noctuidae) under laboratory and field conditions.

    PubMed

    Cui, Jinjie; Luo, Junyu; Van Der Werf, Wopke; Ma, Yan; Xia, Jingyuan

    2011-04-01

    Transgenic cotton (Cossypium hirsutum L.) varieties, adapted to China, have been bred that express two genes for resistance to insects, the CrylAc gene from Bacillus thuringiensis (Berliner) (Bt), and a trypsin inhibitor gene from cowpea (CpTI). Effectiveness of the double gene modification in conferring resistance to cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), was studied in laboratory and field experiments. In each experiment, performance of Bt+CpTI cotton was compared with Bt cotton and to a conventional nontransgenic variety. Larval survival was lower on both types of transgenic variety, compared with the conventional cotton. Survival of first-, second-, and third-stage larvae was lower on Bt+CpTI cotton than on Bt cotton. Plant structures differed in level of resistance, and these differences were similar on Bt and Bt + CpTI cotton. Likewise, seasonal trends in level of resistance in different plant structures were similar in Bt and Bt+CpTI cotton. Both types of transgenic cotton interfered with development of sixth-stage larvae to adults, and no offspring was produced by H. armigera that fed on Bt or Bt+CpTI cotton from the sixth stage onward. First-, second-, and third-stage larvae spent significantly less time feeding on transgenic cotton than on conventional cotton, and the reduction in feeding time was significantly greater on Bt+CpTI cotton than on Bt cotton. Food conversion efficiency was lower on transgenic varieties than on conventional cotton, but there was no significant difference between Bt and Bt+CpTI cotton. In 3-yr field experimentation, bollworm densities were greatly suppressed on transgenic as compared with conventional cotton, but no significant differences between Bt and Bt+CpTI cotton were found. Overall, the results from laboratory work indicate that introduction of the CpTI gene in Bt cotton raises some components of resistance in cotton against H. armigera, but enhanced control of H. armigera under field

  20. Plant growth regulation of Bt-cotton through Bacillus species.

    PubMed

    Pindi, Pavan Kumar; Sultana, Tasleem; Vootla, Praveen Kumar

    2014-06-01

    Deccan plateau in India periodically experiences droughts due to irregular rain fall and the soil in many parts of the region is considered to be poor for farming. Plant growth promoting rhizobacteria are originally defined as root-colonizing bacteria, i.e., Bacillus that cause either plant growth promotion or biological control of plant diseases. The study aims at the isolation of novel Bacillus species and to assess the biotechnological potential of the novel species as a biofertilizer, with respect to their plant growth promoting properties as efficient phosphate-solubilizing bacteria. Seven different strains of Bacillus were isolated from cotton rhizosphere soil near boys' hostel of Palamuru University which belongs to Deccan plateau. Among seven isolated strains, Bacillus strain-7 has shown maximum support for good growth of eight cotton cultivars. This bacterial species is named Bacillus sp. PU-7 based on the phenotypic and phylogenetic analysis. Among eight cotton cultivars, Mahyco has shown high levels of IAA, proteins, chlorophyll, sugars and low level of proline. Efficacy of novel Bacillus sp. PU-7 with Mahyco cultivar has been checked experimentally at field level in four different cotton grown agricultural soils. The strains supported plant growth in almost all the cases, especially in the deep black soil, with a clear evidence of maximum plant growth by increased levels of phytohormone production and biochemical analysis, followed by shallow black soil. Hence, it is inferred that the novel isolate can be used as bioinoculant in the cotton fields.

  1. Broad-scale suppression of cotton bollworm, Helicoverpa armigera (Lepidoptera: Noctuidae), associated with Bt cotton crops in Northern New South Wales, Australia.

    PubMed

    Baker, G H; Tann, C R

    2017-04-01

    The cotton bollworm, Helicoverpa armigera, is a major pest of many agricultural crops in several countries, including Australia. Transgenic cotton, expressing a single Bt toxin, was first used in the 1990s to control H. armigera and other lepidopteran pests. Landscape scale or greater pest suppression has been reported in some countries using this technology. However, a long-term, broad-scale pheromone trapping program for H. armigera in a mixed cropping region in eastern Australia caught more moths during the deployment of single Bt toxin cotton (Ingard®) (1996-2004) than in previous years. This response can be attributed, at least in part, to (1) a precautionary cap (30% of total cotton grown, by area) being applied to Ingard® to restrict the development of Bt resistance in the pest, and (2) during the Ingard® era, cotton production greatly increased (as did that of another host plant, sorghum) and H. armigera (in particular the 3rd and older generations) responded in concert with this increase in host plant availability. However, with the replacement of Ingard® with Bollgard II® cotton (containing two different Bt toxins) in 2005, and recovery of the cotton industry from prevailing drought, H. armigera failed to track increased host-plant supply and moth numbers decreased. Greater toxicity of the two gene product, introduction of no cap on Bt cotton proportion, and an increase in natural enemy abundance are suggested as the most likely mechanisms responsible for the suppression observed.

  2. 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...

  3. 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

  4. Recent evaluations of Bt and non-Bt cotton in the Mississippi Delta

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since the introduction of the first transgenic cotton for the control of caterpillar pests 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, five location...

  5. Impact of single and stacked insect-resistant Bt-cotton on the honey bee and silkworm.

    PubMed

    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 3(rd) day of 5(th) B. mori instar larvae was observed only at the two highest pollen densities (approximately 900 and 8000 grains/cm(2)), 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.

  6. Reproductive biology of two nontarget insect species, Aphis gossypii (Homoptera: Aphididae) and Orius sauteri (Hemiptera: Anthocoridae), on Bt and non-Bt cotton cultivars.

    PubMed

    Zhang, Gui-Fen; Wan, Fang-Hao; Murphy, Sean T; Guo, Jian-Ying; Liu, Wan-Xue

    2008-08-01

    Transgenic Bt cotton, engineered to continuously produce activated delta-endotoxins of the soil bacteria Bacillus thuringiensis, holds great promise in controlling Helicoverpa armigera and other lepidopteran pests. However, it also may impact the invertebrate community, which needs to be clarified. The effects of Bt cotton on two nontarget insects, Aphis gossypii and Orius sauteri, were assessed under semifield and laboratory conditions. Mean total duration of nymphal stages of A. gossypii was shorter (5.9 versus 6.3 d), and rm was higher (0.418 versus 0.394) on conventional Simian 3 (the most frequently planted non-Bt cotton in northern China) than on Bt transgenic NuCOTN 33B (the first Bt cotton commercially planted in China). Mean duration of fourth-instar O. sauteri was significantly longer on transgenic GK-12 (3.7 d) than on NuCOTN 33B (3.2 d), but no different from Simian 3. Mean total mortality was significantly lower on Simian 3 (3.7%) than on GK-12 (14.8%). During the fourth instar, the predator consumed a significantly higher number of prey on Simian 3 (202.3 prey) than on NuCOTN 33B (159.0), whereas the mean total number of A. gossypii prey consumed during the nymphal stage was significantly higher on Simian 3 (336.8 prey) and GK-12 (330.3 prey) than on NuCOTN 33B (275.7). No detrimental effects were detected on development (nymphs, adults, and progeny eggs), fecundity, longevity, and egg viability of O. sauteri on Bt cotton aphids compared with non-Bt cotton aphids. These results suggest that Bt cotton cultivars GK-12 and NuCOTN 33B have no direct effect on nontargets A. gossypii and O. sauteri. Germplasm divergence may account for the negative effects observed on A. gossypii and O. sauteri when reared on NuCOTN 33B or NuCOTN 33B-fed aphids. The biological meanings of the small difference observed between GK-12 and Simian 3 on survival of O. sauteri will require close monitoring over longer time periods.

  7. [Ecological regionalization of cotton varieties based on GGE biplot].

    PubMed

    Xu, Nai-Yin; Zhang, Guo-Wei; Li, Jian; Zhou, Zhi-guo

    2013-03-01

    By using the heritability-adjusted GGE biplot analysis method, and taking the trial sites Anqing, Nanyang, Huanggang, Jingzhou, Wuhan, Xiangyang, Changde, Yueyang, Nanjing, Nantong, Yancheng, Jiujiang, Jianyang, Shehong, and Cixi as the representative cotton-planting areas in the Yangtze River basin, the ecological regionalization of cotton varieties in the basin was made based on the lint cotton yield, and the regionalization results were adjusted by the information ratio (IR) method, aimed to provide scientific basis for the selection of cotton varieties in the cotton-planting areas of the basin. The cotton-planting areas in the Yangtze River basin could be divided into three ecological regions, i.e., the "Sichuan basin cotton region" with Jianyang and Shehong as the representative, the "Nan-Xiang basin cotton region" with Xiangyang and Nanyang as the representative, and the "majority complex cotton region in the Yangtze River basin" including all the other sites in the basin.

  8. Synergistic interactions between Cry1Ac and natural cotton defenses limit survival of Cry1Ac-resistant Helicoverpa zea (Lepidoptera: Noctuidae) on Bt cotton.

    PubMed

    Anilkumar, Konasale J; Sivasupramaniam, Sakuntala; Head, Graham; Orth, Robert; Van Santen, Edzard; Moar, William J

    2009-07-01

    Larvae of the bollworm Helicoverpa zea (Boddie) show some tolerance to Bacillus thuringiensis (Bt) Cry1Ac, and can survive on Cry1Ac-expressing Bt cotton, which should increase resistance development concerns. However, field-evolved resistance has not yet been observed. In a previous study, a population of H. zea was selected for stable resistance to Cry1Ac toxin. In the present study, we determined in laboratory bioassays if larvae of the Cry1Ac toxin-resistant H. zea population show higher survival rates on field-cultivated Bt cotton squares (= flower buds) collected prebloom-bloom than susceptible H. zea. Our results show that Cry1Ac toxin-resistant H. zea cannot complete larval development on Cry1Ac-expressing Bt cotton, despite being more than 150-fold resistant to Cry1Ac toxin and able to survive until pupation on Cry1Ac toxin concentrations greater than present in Bt cotton squares. Since mortality observed for Cry1Ac-resistant H. zea on Bt cotton was higher than expected, we investigated whether Cry1Ac interacts with gossypol and or other compounds offered with cotton powder in artificial diet. Diet incorporation bioassays were conducted with Cry1Ac toxin alone, and with gossypol and 4% cotton powder in the presence and absence of Cry1Ac. Cry1Ac toxin was significantly more lethal to susceptible H. zea than to resistant H. zea, but no difference in susceptibility to gossypol was observed between strains. However, combinations of Cry1Ac with gossypol or cotton powder were synergistic against resistant, but not against susceptible H. zea. Gossypol concentrations in individual larvae showed no significant differences between insect strains, or between larvae fed gossypol alone vs. those fed gossypol plus Cry1Ac. These results may help explain the inability of Cry1Ac-resistant H. zea to complete development on Bt cotton, and the absence of field-evolved resistance to Bt cotton by this pest.

  9. A perspective on management of Helicoverpa armigera: transgenic Bt cotton, IPM, and landscapes.

    PubMed

    Downes, Sharon; Kriticos, Darren; Parry, Hazel; Paull, Cate; Schellhorn, Nancy; Zalucki, Myron P

    2017-03-01

    Helicoverpa armigera is a major pest of agriculture, horticulture and floriculture throughout the Old World and recently invaded parts of the New World. We overview of the evolution in thinking about the application of area-wide approaches to assist with its control by the Australian Cotton Industry to highlight important lessons and future challenges to achieving the same in the New World. An over-reliance of broad-spectrum insecticides led to Helicoverpa spp. in Australian cotton rapidly became resistant to DDT, synthetic pyrethroids, organophosphates, carbamates and endosulfan. Voluntary strategies were developed to slow the development of insecticide resistance, which included rotating chemistries and basing spray decisions on thresholds. Despite adoption of these practices, insecticide resistance continued to develop until the introduction of genetically modified cotton provided a platform for augmenting Integrated Pest Management in the Australian cotton industry. Compliance with mandatory resistance management plans for Bt cotton necessitated a shift from pest control at the level of individual fields or farms towards a coordinated area-wide landscape approach. Our take-home message for control of H. armigera is that resistance management is essential in genetically modified crops and must be season long and area-wide to be effective. © 2016 Society of Chemical Industry.

  10. Impact of water content and temperature on the degradation of Cry1Ac protein in leaves and buds of Bt cotton in the soil.

    PubMed

    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.

  11. Decaplex and real-time PCR based detection of MON531 and MON15985 Bt cotton events.

    PubMed

    Randhawa, Gurinder Jit; Chhabra, Rashmi; Singh, Monika

    2010-09-22

    The genetically modified (GM) Bt crops expressing delta-endotoxins from Bacillus thuringiensis provide protection against a wide range of lepidopteron insect pests throughout the growing season of the plant. Bt cotton is the only commercialized crop in India that is planted on an area of 7.6 million hectares. With the increase in development and commercialization of transgenic crops, it is necessary to develop appropriate qualitative and quantitative methods for detection of different transgenic events. The present study reports on the development of a decaplex polymerase chain reaction (PCR) assay for simultaneous detection of transgene sequences, specific transgene constructs, and endogenous stearoyl acyl desaturase (Sad1) gene in two events of Bt cotton, i.e., MON531 and MON15985. The decaplex PCR assay is an efficient tool to identify and discriminate the two major commercialized events of Bt cotton, i.e., MON531 and MON15985, in India. Real-time PCR assays were also developed for quantification of cry1Ac and cry2Ab genes being employed in these two events. The quantitative method was developed using seven serial dilutions containing different levels of Bt cotton DNA mixed with a non-Bt counterpart ranging from 0.01 to 100%. The results revealed that the biases from the true value and the relative standard deviations were all within the range of ±20%. The limit of quantification (LOQ) of the developed real-time PCR method has also been established up to 0.01%.

  12. 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

  13. Nutrient omission in Bt cotton affects soil organic carbon and nutrients status

    NASA Astrophysics Data System (ADS)

    Aladakatti, Y. R.; Biradar, D. P.; Satyanarayana, T.; Majumdar, K.; Shivamurthy, D.

    2012-04-01

    Studies carried out at the University of Agricultural Sciences, Dharwad, India, in medium black soils assessed the effect of nutrient omission in Bt cotton and its effect on the soil organic carbon (SOC) and available nutrients at the end of second consecutive year of nutrient omission. The study also assessed the extent of contribution of the macro and micronutrients towards seed cotton yield. The experiment consisting 11 treatments omitting a nutrient in each treatment including an absolute control without any nutrients was conducted in a Randomised Block Design with three replications. Cotton crop sufficiently fertilized with macro and micro nutrients (165 : 75 : 120 NPK kg ha-1 and 20 kg each of CaSO4, and MgSO4, 10 kg of S, 20 kg each of ZnSO4, FeSO4 and 0.1 per cent Boron twice as foliar spray) was taken as a standard check to assess the contribution of each nutrient in various nutrient omission treatments. Soils of each treatment were analysed initially and after each crop of cotton for SOC and available nutrient status. Results indicated that the SOC decreased after each crop of cotton in absolute control where no nutrients were applied (0.50 % to 0.38 %) and also in the N omission treatment (0.50 % to 0.35 %). But there was no significant impact of omission of P, K and other nutrients on soil organic carbon. Soil available N, P and K in the soil were reduced as compared to the initial soil status after first and second crop of cotton in the respective treatment where these nutrients were omitted. The soil available N, P and K were reduced to the extent of 61 kg ha-1, 7.1 kg ha-1 and 161.9 kg ha-1 in the respective nutrient omission treatment at end of second crop of cotton as compared to the initial status of these nutrients in the soil. This might be due to the mining of these nutrients from the soil nutrient pool with out addition of these nutrients extraneously. The nutrient status of N, P and K remained almost similar in omission of other nutrients

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

    PubMed

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

    2015-01-14

    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.

  15. 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

  16. [Effects of high temperature on Bt proteins expression and nitrogen metabolic physiology in square of Bt cotton at the peak squaring stage].

    PubMed

    Chen, Yuan; Han, Yong; Wang, Jun; Hua, Ming-Ming; Gu, Chao; Li, Guo-Sheng; Zhang, Xiang; Chen, De-Hua

    2014-09-01

    Taking Bt cotton Sikang 1 (a conventional cultivar), Sikang 3 (a hybrid cultivar) from China and 99B (a conventional cultivar), Daiza 1 (a hybrid cultivar) from USA as test materials, the effects of different high temperatures on thesquare Bt proteins expression and nitrogen metabolic physiology were investigated. The results showed that the square Bt protein contents of the four cultivars decreased significantly above 38 °C compared with that at 32 °C. The higher the temperature was above 38 °C, the greater the reduction extent of the Bt protein content was. The square Bt protein contents of the hybrid cultivars were higher than that of the conventional cultivars, and were less reduced under the high temperature stress. The cultivars with bigger reductions in Bt protein content also showed greater reductions in the square soluble protein contents, pyruvic transaminase activities and glutamic oxaloacetic transaminase activities, while larger increments were detected for the square free amino acid contents, proteinsase activities and peptidase activities.

  17. 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.

  18. [Effect of plantation of transgenic Bt cotton on the amount of rhizospheric soil microorganism and bacterial diversity in the cotton region of Yellow River basin].

    PubMed

    Na, Ri-Su; Yu, Hong; Yang, Dian-Lin; Zhao, Jian-Ning; Li, Gang; Na, Bu-Qi; Liu, Ling

    2011-01-01

    Traditional culture-dependent method and PCR-DGGE were adopted to investigate the amount of microorganism and bacterial diversity in rhizospheric soil of transgenic Bt cotton in four provinces of Yellow River basin at four growth stages, i.e., 30, 60, 90, and 120 days after sowing. In the same province and at the same growth stage, no significant difference was observed in the amount of microorganism in rhizospheric soils of transgenic and non-transgenic Bt cottons. Within the same province the amount of microorganism was mainly affected by growth stage; while in different provinces, it was greatly affected by regional conditions. In the four provinces, the bacterial diversity in rhizospheric soil of transgenic Bt cotton was abundant; and in the same province and at the same growth stage, there were no significant differences in the Shannon index, evenness, and richness of bacteria in rhizospheric soils of transgenic and non-transgenic Bt cottons. In different provinces, the bacterial diversity in rhizospheric soils was dependent on regional conditions, but the difference was rather small.

  19. [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

  20. DNA-based diagnostics for genetically modified cotton: decaplex PCR assay to differentiate MON531 and MON15985 Bt cotton events.

    PubMed

    Randhawa, Gurinder Jit; Singh, Monika; Chhabra, Rashmi

    2013-01-01

    The adoption rate and global area under cultivation of genetically modified (GM) crops is dramatically increasing in recent past. GM cotton has occupied 25.0 million hectares (mha) comprising 15.6% of the global area under GM cultivation. Bt cotton, expressing delta-endotoxins from Bacillus thuringiensis (Bt), is the only commercialized crop in India that is planted on an area of 10.6 mha. With the increase in development and commercialization of GM crops, it is necessary to develop appropriate qualitative and quantitative methods for detection of different GM events. Robust diagnostics for GM detection need to be developed and implemented to monitor and detect different events of GM cotton in India. This chapter summarizes the methods based on polymerase chain reaction (PCR) being employed for detection of different GM events of cotton. We describe a decaplex PCR method for identification and differentiation of two major commercialized events of Bt cotton, i.e., MON531 and MON15985, in India.

  1. 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.

  2. 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

  3. Current status of insecticide resistance in Helicoverpa armigera after 15 years of Bt cotton planting in China.

    PubMed

    Yang, Yihua; Li, Yapeng; Wu, Yidong

    2013-02-01

    Insecticide resistance was an important factor responsible for outbreaks of Helicoverpa armigera (Hübner) in China in the early 1990s. Bt cotton has been adopted in China since 1997, and has resulted in a reduction of insecticide use for H. armigera control. After 15 yr of Bt cotton planting, in 2011 we surveyed resistance to fenvalerate, phoxim, and emamectin benzoate in 16 field populations of H. armigera collected from major cotton production areas of China. Fourteen populations from northern China showed very strong resistance to fenvalerate (from 43- to 830-fold) and low levels of resistance to phoxim (3.0- to 8.9-fold) when compared with the susceptible SCD strain of H. armigera, whereas two populations from northwestern China showed low levels of resistance to fenvalerate (3.0- and 10-fold) and no resistance to phoxim (0.7- and 0.9-fold). Synergist bioassays demonstrated that oxidase-based detoxification was involved in fenvalerate resistance and esterase-based detoxification in phoxim resistance in the resistant field populations. In comparison with the resistance in field populations before Bt cotton adoption, we observed a maintenance of high levels of fenvalerate resistance, but a reversion of phoxim resistance from high levels to low levels in the field populations of H. armigera from northern China. All 16 field populations from both northern China and northwestern China were susceptible to emamectin benzoate (with about two-fold variations in LD50s among populations), but the SCD strain has an inherent tolerance of 11-fold compared with the most susceptible field population (Xiajin-1). Emamectin benzoate is not cross resistant to fenvalerate and may provide an alternative option for H. armigera control in China, if the efficacy of Bt cotton is compromised by Bt resistance in the field.

  4. Effects of transgenic Bt cotton on the population density, oviposition behavior, development, and reproduction of a nontarget pest, Adelphocoris suturalis (Hemiptera: Miridae).

    PubMed

    Li, Guoping; Feng, Hongqiang; Chen, Peiyu; Wu, Shaoying; Liu, Bing; Qiu, Feng

    2010-08-01

    Transgenic cotton has shown great promise for the control of target pest insects; however, frequent outbreaks of nontarget pest mirids has been recorded in recent years in northern China. To test the hypothesis that transgenic cotton contributes to nontarget pest outbreaks, we studied the impact of transgenic Bt cottons (both Bt and Bt + CpTI) on the fitness of nontarget pest Adelphocoris suturalis Jakovlev. No significant differences were detected between population densities of A. suturalis in unsprayed nontransgenic cottons and in unsprayed transgenic Bt cottons in 2007, 2008, and 2009. No difference in preferred oviposition site or egg production was detected between transgenic and nontransgenic cottons in both free choice and no choice tests. No difference in life table parameters was detected for A. suturalis between Bt cottons and nontransgenic cottons. All these results indicated that transgenic crops did not contribute to the nontarget pest outbreaks when being compared with their parental lines. The possible reasons for intensified pest status of A. suturalis, such as decrease of pesticide application, deficient natural enemies, and area-wide shift of cotton varieties, were discussed.

  5. Difference in leaf water use efficiency/photosynthetic nitrogen use efficiency of Bt-cotton and its conventional peer

    PubMed Central

    Guo, Ruqing; Sun, Shucun; Liu, Biao

    2016-01-01

    This study is to test the effects of Bt gene introduction on the foliar water/nitrogen use efficiency in cotton. We measured leaf stomatal conductance, photosynthetic rate, and transpiration rate under light saturation condition at different stages of a conventional cultivar (zhongmian no. 16) and its counterpart Bt cultivar (zhongmian no. 30) that were cultured on three levels of fertilization, based on which leaf instantaneous water use efficiency was derived. Leaf nitrogen concentration was measured to calculate leaf photosynthetic nitrogen use efficiency, and leaf δ13C was used to characterize long term water use efficiency. Bt cultivar was found to have lower stomatal conductance, net photosynthetic rates and transpiration rates, but higher instantaneous and long time water use efficiency. In addition, foliar nitrogen concentration was found to be higher but net photosynthetic rate was lower in the mature leaves of Bt cultivar, which led to lower photosynthetic nitrogen use efficiency. This might result from the significant decrease of photosynthetic rate due to the decrease of stomatal conductance. In conclusion, our findings show that the introduction of Bt gene should significantly increase foliar water use efficiency but decrease leaf nitrogen use efficiency in cotton under no selective pressure. PMID:27628897

  6. Difference in leaf water use efficiency/photosynthetic nitrogen use efficiency of Bt-cotton and its conventional peer.

    PubMed

    Guo, Ruqing; Sun, Shucun; Liu, Biao

    2016-09-15

    This study is to test the effects of Bt gene introduction on the foliar water/nitrogen use efficiency in cotton. We measured leaf stomatal conductance, photosynthetic rate, and transpiration rate under light saturation condition at different stages of a conventional cultivar (zhongmian no. 16) and its counterpart Bt cultivar (zhongmian no. 30) that were cultured on three levels of fertilization, based on which leaf instantaneous water use efficiency was derived. Leaf nitrogen concentration was measured to calculate leaf photosynthetic nitrogen use efficiency, and leaf δ(13)C was used to characterize long term water use efficiency. Bt cultivar was found to have lower stomatal conductance, net photosynthetic rates and transpiration rates, but higher instantaneous and long time water use efficiency. In addition, foliar nitrogen concentration was found to be higher but net photosynthetic rate was lower in the mature leaves of Bt cultivar, which led to lower photosynthetic nitrogen use efficiency. This might result from the significant decrease of photosynthetic rate due to the decrease of stomatal conductance. In conclusion, our findings show that the introduction of Bt gene should significantly increase foliar water use efficiency but decrease leaf nitrogen use efficiency in cotton under no selective pressure.

  7. 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

  8. 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.

  9. Visual and Real-Time Event-Specific Loop-Mediated Isothermal Amplification Based Detection Assays for Bt Cotton Events MON531 and MON15985.

    PubMed

    Randhawa, Gurinder Jit; Chhabra, Rashmi; Bhoge, Rajesh K; Singh, Monika

    2015-01-01

    Bt cotton events MON531 and MON15985 are authorized for commercial cultivation in more than 18 countries. In India, four Bt cotton events have been commercialized; more than 95% of total area under genetically modified (GM) cotton cultivation comprises events MON531 and MON15985. The present study reports on the development of efficient event-specific visual and real-time loop-mediated isothermal amplification (LAMP) assays for detection and identification of cotton events MON531 and MON15985. Efficiency of LAMP assays was compared with conventional and real-time PCR assays. Real-time LAMP assay was found time-efficient and most sensitive, detecting up to two target copies within 35 min. The developed real-time LAMP assays, when combined with efficient DNA extraction kit/protocol, may facilitate onsite GM detection to check authenticity of Bt cotton seeds.

  10. Non-recessive Bt toxin resistance conferred by an intracellular cadherin mutation in field-selected populations of cotton bollworm.

    PubMed

    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.

  11. Tri-trophic interactions between Bt cotton, the herbivore Aphis gossypii Glover (Homoptera: Aphididae), and the predator Chrysopa pallens (Rambur) (Neuroptera: Chrysopidae).

    PubMed

    Guo, Jian-Ying; Wan, Fang-Hao; Dong, Liang; Lövei, Gábor L; Han, Zhao-Jun

    2008-02-01

    Tri-trophic impacts of transgenic Bacillus thuringiensis (Bt) cotton GK12 and NuCOTN 99B were studied using a predator, the great lacewing Chrysopa pallens (Rambur), and its prey, the cotton aphid Aphis gossypii Glover, in laboratory feeding experiments. The parental nontransgenic cotton cultivar of GK12 was used as control. The predator was fed with uniform (aphids from a single cultivar) or mixed prey (aphids from the three cotton cultivars provided on alternate days). Mortality and development of the immature stages, pupal body mass, adult sex ratio, fecundity, and egg viability of C. pallens were measured. When fed GK12-originated aphid prey, pupal body mass of C. pallens was significantly higher than that of the control, more females emerged, and these females laid significantly more eggs. Other parameters were not impacted. Females emerging from larvae maintained on NuCOTN 99B-originated prey laid fewer eggs than those maintained on GK12. Other measurements did not differ significantly between the two Bt cotton cultivars. Compared with the control, mixed feeding significantly prolonged pupal development time and increased pupal body mass and percentage of females but did not affect other parameters. These results indicate that C. pallens is sensitive to aphid prey from different cotton cultivars. Transgenic Bt cotton GK12-originated aphid prey has no adverse impact on survival, development, and fecundity of C. pallens. Between the two Bt cotton cultivars, NuCOTN 99B-originated aphid prey provided to C. pallens in the larval stage may lower female fecundity. Mixed feeding of C. pallens with the two Bt cotton-originated prey and non-Bt prey may have some adverse impacts on pupal development.

  12. 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...

  13. 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...

  14. Effective dominance of resistance of Spodoptera frugiperda to Bt maize and cotton varieties: implications for resistance management

    NASA Astrophysics Data System (ADS)

    Horikoshi, Renato J.; Bernardi, Daniel; Bernardi, Oderlei; Malaquias, José B.; Okuma, Daniela M.; Miraldo, Leonardo L.; Amaral, Fernando S. De A. E.; Omoto, Celso

    2016-10-01

    The resistance of fall armyworm (FAW), Spodoptera frugiperda, has been characterized to some Cry and Vip3A proteins of Bacillus thuringiensis (Bt) expressed in transgenic maize in Brazil. Here we evaluated the effective dominance of resistance based on the survival of neonates from selected Bt-resistant, heterozygous, and susceptible (Sus) strains of FAW on different Bt maize and cotton varieties. High survival of strains resistant to the Cry1F (HX-R), Cry1A.105/Cry2Ab (VT-R) and Cry1A.105/Cry2Ab/Cry1F (PW-R) proteins was detected on Herculex, YieldGard VT PRO and PowerCore maize. Our Vip3A-resistant strain (Vip-R) exhibited high survival on Herculex, Agrisure Viptera and Agrisure Viptera 3 maize. However, the heterozygous from HX-R × Sus, VT-R × Sus, PW-R × Sus and Vip-R × Sus had complete mortality on YieldGard VT PRO, PowerCore, Agrisure Viptera, and Agrisure Viptera 3, whereas the HX-R × Sus and Vip-R × Sus strains survived on Herculex maize. On Bt cotton, the HX-R, VT-R and PW-R strains exhibited high survival on Bollgard II. All resistant strains survived on WideStrike, but only PW-R and Vip-R × Sus survived on TwinLink. Our study provides useful data to aid in the understanding of the effectiveness of the refuge strategy for Insect Resistance Management of Bt plants.

  15. Effective dominance of resistance of Spodoptera frugiperda to Bt maize and cotton varieties: implications for resistance management.

    PubMed

    Horikoshi, Renato J; Bernardi, Daniel; Bernardi, Oderlei; Malaquias, José B; Okuma, Daniela M; Miraldo, Leonardo L; Amaral, Fernando S de A E; Omoto, Celso

    2016-10-10

    The resistance of fall armyworm (FAW), Spodoptera frugiperda, has been characterized to some Cry and Vip3A proteins of Bacillus thuringiensis (Bt) expressed in transgenic maize in Brazil. Here we evaluated the effective dominance of resistance based on the survival of neonates from selected Bt-resistant, heterozygous, and susceptible (Sus) strains of FAW on different Bt maize and cotton varieties. High survival of strains resistant to the Cry1F (HX-R), Cry1A.105/Cry2Ab (VT-R) and Cry1A.105/Cry2Ab/Cry1F (PW-R) proteins was detected on Herculex, YieldGard VT PRO and PowerCore maize. Our Vip3A-resistant strain (Vip-R) exhibited high survival on Herculex, Agrisure Viptera and Agrisure Viptera 3 maize. However, the heterozygous from HX-R × Sus, VT-R × Sus, PW-R × Sus and Vip-R × Sus had complete mortality on YieldGard VT PRO, PowerCore, Agrisure Viptera, and Agrisure Viptera 3, whereas the HX-R × Sus and Vip-R × Sus strains survived on Herculex maize. On Bt cotton, the HX-R, VT-R and PW-R strains exhibited high survival on Bollgard II. All resistant strains survived on WideStrike, but only PW-R and Vip-R × Sus survived on TwinLink. Our study provides useful data to aid in the understanding of the effectiveness of the refuge strategy for Insect Resistance Management of Bt plants.

  16. Effective dominance of resistance of Spodoptera frugiperda to Bt maize and cotton varieties: implications for resistance management

    PubMed Central

    Horikoshi, Renato J.; Bernardi, Daniel; Bernardi, Oderlei; Malaquias, José B.; Okuma, Daniela M.; Miraldo, Leonardo L.; Amaral, Fernando S. de A. e; Omoto, Celso

    2016-01-01

    The resistance of fall armyworm (FAW), Spodoptera frugiperda, has been characterized to some Cry and Vip3A proteins of Bacillus thuringiensis (Bt) expressed in transgenic maize in Brazil. Here we evaluated the effective dominance of resistance based on the survival of neonates from selected Bt-resistant, heterozygous, and susceptible (Sus) strains of FAW on different Bt maize and cotton varieties. High survival of strains resistant to the Cry1F (HX-R), Cry1A.105/Cry2Ab (VT-R) and Cry1A.105/Cry2Ab/Cry1F (PW-R) proteins was detected on Herculex, YieldGard VT PRO and PowerCore maize. Our Vip3A-resistant strain (Vip-R) exhibited high survival on Herculex, Agrisure Viptera and Agrisure Viptera 3 maize. However, the heterozygous from HX-R × Sus, VT-R × Sus, PW-R × Sus and Vip-R × Sus had complete mortality on YieldGard VT PRO, PowerCore, Agrisure Viptera, and Agrisure Viptera 3, whereas the HX-R × Sus and Vip-R × Sus strains survived on Herculex maize. On Bt cotton, the HX-R, VT-R and PW-R strains exhibited high survival on Bollgard II. All resistant strains survived on WideStrike, but only PW-R and Vip-R × Sus survived on TwinLink. Our study provides useful data to aid in the understanding of the effectiveness of the refuge strategy for Insect Resistance Management of Bt plants. PMID:27721425

  17. 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.

  18. A comprehensive assessment of the effects of Bt cotton on Coleomegilla maculata demonstrates no detrimental effects by Cry1Ac and Cry2Ab.

    PubMed

    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.

  19. 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

  20. Insect Control Without Bt

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding potential to grow conventional cottons that do not express Bt insecticidal proteins requires an appreciation for the historical impact of Bt cotton on cotton insects. Insects have long been exposed to Bacillus thuringiensis, a common soil-borne bacterium. Commercial deployment of B...

  1. 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

  2. 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

    2016-06-15

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

  3. The substantive equivalence of transgenic (Bt and Chi) and non-transgenic cotton based on metabolite profiles.

    PubMed

    Modirroosta, Bentol Hoda; Tohidfar, Masoud; Saba, Jalal; Moradi, Foad

    2014-03-01

    Compositional studies comparing transgenic with non-transgenic counterpart plants are almost universally required by governmental regulatory bodies. In the present study, two T(2) transgenic cotton lines containing chitinase (Line 11/57) and Bt lines (Line 61) were compared with non-transgenic counterpart. To do this, biochemical characteristics of leaves and seeds, including amino acids, fatty acids, carbohydrates, anions, and cations contents of the studied lines were analyzed using GC/MS, high-performance liquid chromatography (HPLC), and ion chromatography (IC) analyzers, respectively. polymerase chain reaction (PCR) and Western blot analyses confirmed the presence and expression of Chi and Bt genes in the studied transgenic lines. Although, compositional analysis of leaves contents confirmed no significant differences between transgenic and non-transgenic counterpart lines, but it was shown that glucose content of chitinase lines, fructose content of transgenic lines (Bt and chitinase) and asparagine and glutamine of chitinase lines were significantly higher than the non-transgenic counterpart plants. Both the transgenic lines (Bt and chitinase) showed significant decrease in the amounts of sodium in comparison to the non-transgenic counterpart plants. The experiments on the seeds showed that histidine, isoleucine, leucine, and phenylalanine contents of all transgenic and non-transgenic lines were the same, whereas other amino acids were significantly increased in the transgenic lines. Surprisingly, it was observed that the concentrations of stearic acid, myristic acid, oleic acid, and linoleic acid in the chitinase line were significantly different than those of non-transgenic counterpart plants, but these components were the same in both Bt line and its non-transgenic counterpart. It seems that more changes observed in the seed contents than leaves is via this point that seeds are known as metabolites storage organs, so they show greater changes in the

  4. [Comparison between transgenic insect-resistant cotton expressing Cry1Ac protein and its parental variety in rhizospheric fungal diversity].

    PubMed

    Pan, Jian-Gang; Jiao, Hai-Hua; Bai, Zhi-Hui; Qi, Hong-Yan; Ma, An-Zhou; Zhuang, Guo-qiang; Zhang, Hong-xun

    2014-11-01

    The dynamics of rhizospheric fungal diversity and biomass at different sampling stages associated with two transgenic insectresistant cottons expressing Cry1Ac protein and their control varieties were studied under greenhouse conditions, followed by PCR-denaturing gradient gel electrophoresis (PCR-DGGE) and quantitative real-time polymerase chain reaction (Q-PCR), in order to evaluate the ecological security of planting transgenic cotton expressing Cry1Ac protein. The results indicated that the fungal superior bands in rhizosphere of transgenic Bt cotton were similar with that of control cotton at four sampling stages, the more obvious difference in the blurred bands among transgenic Bt cotton, JM20 and SHIYUAN321 was detected. The rhizospheric fungal biomass of transgenic Bt cotton SGK321 was significantly lower than that of its parental control cotton at seedling stage, while the slight decrease in fungal biomass of transgenic Bt cotton XP188 was detected at boll forming stage, the ill-defined decrease, even growing tendency in two transgenic Bt cottons was detected at other stages. However, the difference of rhizospheric fungal community compositions and biomass was not only existed between transgenic cotton and its control, but also between SHIYUAN321 and JM20, and the same phenomenon was also detected between transgenic Bt cotton SGK321 and XP188. Hence, Bt protein is not the only incentive resulting in the difference in fungal community composition and diversity, the decrease in biomass between transgenic cotton and untransgenic cotton, different cotton varieties has an effect on them.

  5. 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

  6. Farm-scale evaluation of the impacts of transgenic cotton on biodiversity, pesticide use, and yield.

    PubMed

    Cattaneo, Manda G; Yafuso, Christine; Schmidt, Chris; Huang, Cho-ying; Rahman, Magfurar; Olson, Carl; Ellers-Kirk, Christa; Orr, Barron J; Marsh, Stuart E; Antilla, Larry; Dutilleul, Pierre; Carrière, Yves

    2006-05-16

    Higher yields and reduced pesticide impacts are needed to mitigate the effects of agricultural intensification. A 2-year farm-scale evaluation of 81 commercial fields in Arizona show that use of transgenic Bacillus thuringiensis (Bt) cotton reduced insecticide use, whereas transgenic cotton with Bt protein and herbicide resistance (BtHr) did not affect herbicide use. Transgenic cotton had higher yield than nontransgenic cotton for any given number of insecticide applications. However, nontransgenic, Bt and BtHr cotton had similar yields overall, largely because higher insecticide use with nontransgenic cotton improved control of key pests. Unlike Bt and BtHr cotton, insecticides reduced the diversity of nontarget insects. Several other agronomic and ecological factors also affected biodiversity. Nevertheless, pairwise comparisons of diversity of nontarget insects in cotton fields with diversity in adjacent noncultivated sites revealed similar effects of cultivation of transgenic and nontransgenic cotton on biodiversity. The results indicate that impacts of agricultural intensification can be reduced when replacement of broad-spectrum insecticides by narrow-spectrum Bt crops does not reduce control of pests not affected by Bt crops.

  7. Farm-scale evaluation of the impacts of transgenic cotton on biodiversity, pesticide use, and yield

    PubMed Central

    Cattaneo, Manda G.; Yafuso, Christine; Schmidt, Chris; Huang, Cho-ying; Rahman, Magfurar; Olson, Carl; Ellers-Kirk, Christa; Orr, Barron J.; Marsh, Stuart E.; Antilla, Larry; Dutilleul, Pierre; Carrière, Yves

    2006-01-01

    Higher yields and reduced pesticide impacts are needed to mitigate the effects of agricultural intensification. A 2-year farm-scale evaluation of 81 commercial fields in Arizona show that use of transgenic Bacillus thuringiensis (Bt) cotton reduced insecticide use, whereas transgenic cotton with Bt protein and herbicide resistance (BtHr) did not affect herbicide use. Transgenic cotton had higher yield than nontransgenic cotton for any given number of insecticide applications. However, nontransgenic, Bt and BtHr cotton had similar yields overall, largely because higher insecticide use with nontransgenic cotton improved control of key pests. Unlike Bt and BtHr cotton, insecticides reduced the diversity of nontarget insects. Several other agronomic and ecological factors also affected biodiversity. Nevertheless, pairwise comparisons of diversity of nontarget insects in cotton fields with diversity in adjacent noncultivated sites revealed similar effects of cultivation of transgenic and nontransgenic cotton on biodiversity. The results indicate that impacts of agricultural intensification can be reduced when replacement of broad-spectrum insecticides by narrow-spectrum Bt crops does not reduce control of pests not affected by Bt crops. PMID:16675554

  8. 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...

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

    PubMed

    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.

  10. 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

    2016-02-01

    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.

  11. 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

  12. Ultra-structure and histochemistry of digestive cells of Podisus nigrispinus (Hemiptera: Pentatomidae) fed with prey reared on bt-cotton.

    PubMed

    da Cunha, Franklin M; Caetano, Flávio H; Wanderley-Teixeira, Valéria; Torres, Jorge B; Teixeira, Alvaro A C; Alves, Luiz C

    2012-02-01

    The toxic effects of Bt proteins from the body of the prey/host to predators and parasitoids have been investigated as a route of impact on non-target insects of Bt crops. This research aimed to analyze ultrastructural changes and histochemistry in digestive cells of the middle region of the midgut of Podisus nigrispinus fed, since its second instar, with Spodoptera frugiperda reared on Bt cotton variety Acala90 B, which expresses the toxin Cry 1Ac, and its non-Bt isoline Acala 90. Fragments of the midgut of P. nigrispinus were analyzed by electron microscopy. For the histochemical analysis, Bromophenol Blue, Periodic Acid Schiff von Kossa, Alcian Blue pH 2.5 and Sudan Black were used. The Cry1Ac toxin of Bt cotton ingested by S. frugiperda promotes a disorganization in the perimicrovillar matrix of P. nigrispinus (third trophic level), thus generating ultrastructural changes in the digestive cells, as elongation of microvilli, presence of spherocrystals and granules of different electron densities, in addition to altering the distribution pattern of glycogen, lipids and calcium of these cells in the median region of the midgut. Thus, we conclude that species moderately susceptible to Cry1Ac toxin, such as S. frugiperda, can acquire this toxin and expose it to P. nigrispinus, which can interfere with your ability to predation.

  13. 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...

  14. 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 ...

  15. 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

  16. 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.

  17. 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...

  18. 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.

  19. 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.

  20. Cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton is a significant agricultural commodity throughout the world that is used primarily for its fibers to manufacture textiles, but with notable secondary value for its seeds. As cotton oil mills began to operate and products other than whole cottonseed became available, the value of cottonseed ...

  1. Diversity of arthropod community in transgenic poplar-cotton ecosystems.

    PubMed

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

    2015-12-02

    Poplar-cotton agro-ecosystems are the main agricultural planting modes of plain cotton fields in China. Here, we performed a systematic survey of the diversity and population of arthropod communities in four different combination of poplar-cotton eco-systems, including I) non-transgenic poplar and non-transgenic cotton fields; II) non-transgenic poplar and transgenic cotton fields [Bacillus thuringiensis (Bt) cotton]; III) Bt transgenic poplar (high insect resistant strain Pb29) and non-transgenic cotton; and IV) transgenic poplar and transgenic cotton fields, over a period of 3 years. Based on the statistical methods used to investigate community ecology, the effects of transgenic ecosystems on the whole structure of the arthropod community, on the structure of arthropods in the nutritive layer, and on the similarity of arthropod communities were evaluated. The main results were as follows: the transgenic poplar-cotton ecosystem has a stronger inhibitory effect on insect pests and has no impact on the structure of the arthropod community, and therefore, maintains the diversity of the arthropod community. The character index of the community indicated that the structure of the arthropod community of the transgenic poplar-cotton ecosystem was better than that of the poplar-cotton ecosystem, and that system IV had the best structure. As for the abundance of nutritional classes, the transgenic poplar-cotton ecosystem was also better than that of the non-transgenic poplar-cotton ecosystem. The cluster analysis and similarity of arthropod communities between the four different transgenic poplar-cotton ecosystems illustrated that the structure of the arthropod community excelled in the small sample of the transgenic poplar-cotton ecosystems.

  2. 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.

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

    PubMed Central

    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. 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.

  5. 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.

  6. Stink bug host preferences: colonization, oviposition, and feeding on cotton.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Relative colonization rates of stink bug species among host crops grown in the Southeastern US are needed to parameterize a landscape model that seeks to predict stink bug populations in Bt cotton. We sampled stink bugs in Bt cotton, non-Bt cotton, soybean and peanuts over 3 years and 3 sites in the...

  7. 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...

  8. Brazilian free-tailed bats as insect pest regulators in transgenic and conventional cotton crops.

    PubMed

    Federico, Paula; Hallam, Thomas G; McCracken, Gary F; Purucker, S Thomas; Grant, William E; Correa-Sandoval, A Nelly; Westbrook, John K; Medellin, Rodrigo A; Cleveland, Cutler J; Sansone, Chris G; López, Juan D; Betke, Margrit; Moreno-Valdez, Arnulfo; Kunz, Thomas H

    2008-06-01

    During the past 12000 years agricultural systems have transitioned from natural habitats to conventional agricultural regions and recently to large areas of genetically engineered (GE) croplands. This GE revolution occurred for cotton in a span of slightly more than a decade during which a switch occurred in major cotton production areas from growing 100% conventional cotton to an environment in which 95% transgenics are grown. Ecological interactions between GE targeted insects and other insectivorous insects have been investigated. However, the relationships between ecological functions (such as herbivory and ecosystem transport) and agronomic benefits of avian or mammalian insectivores in the transgenic environment generally remain unclear, although the importance of some agricultural pest management services provided by insectivorous species such as the Brazilian free-tailed bat, Tadarida brasiliensis, have been recognized. We developed a dynamic model to predict regional-scale ecological functions in agricultural food webs by using the indicators of insect pest herbivory measured by cotton boll damage and insect emigration from cotton. In the south-central Texas Winter Garden agricultural region we find that the process of insectivory by bats has a considerable impact on both the ecology and valuation of harvest in Bacillus thuringiensis (Bt) transgenic and nontransgenic cotton crops. Predation on agricultural pests by insectivorous bats may enhance the economic value of agricultural systems by reducing the frequency of required spraying and delaying the ultimate need for new pesticides. In the Winter Garden region, the presence of large numbers of insectivorous bats yields a regional summer dispersion of adult pest insects from Bt cotton that is considerably reduced from the moth emigration when bats are absent in either transgenic or non-transgenic crops. This regional decrease of pest numbers impacts insect herbivory on a transcontinental scale. With a few

  9. Fifty years of the integrated control concept: the role of landscape ecology in IPM in San Joaquin valley cotton.

    PubMed

    Goodell, Peter B

    2009-12-01

    In defining the integrated control concept, Stern, Smith, van den Bosch and Hagan described 'understanding the ecosystem' as a key underpinning of the concept. In following years, Stern and van den Bosch continued to refine and expand the role of the ecological landscape. They and their colleagues developed cultural practices that took advantage of this understanding to limit the need of pesticide intervention in cotton in the San Joaquin Valley during the 1960s and 1970s. Research and extension activities in the intervening years built upon those fundamental concepts using geospatial tools and analytical techniques to refine current understanding and develop ecological landscape level approaches to manage Lygus hesperus (Knight) in San Joaquin Valley cotton, Gossypium hirsutum (L.) and more recently G. barbadense (L.). The result has been a significant drop in insecticide use against L. hesperus, with less than one application per season during the 1990 s and early 2000s.

  10. 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.

  11. 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

  12. 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.

  13. Effects of proportion and configuration of Bacillus thuringiensis cotton on pest abundance, damage, and yield.

    PubMed

    Chilcutt, Charles F

    2007-08-01

    Bacillus thuringiensis (Bt) transgenic cotton, Gossypium hirsutum L., kills several economically important pests, reducing injury and increasing yields. Refuges of non-Bt cotton are currently planted with Bt cotton in different designs to slow pest resistance evolution. To compare the effects of differences in Bt/non-Bt plant heterogeneity found in different refuge designs on square (flower bud) damage, abscissions, sap-feeding herbivore densities, and yield in cotton, four types of 24-row cotton plots were planted in 2001 and 2002: 1) seed mixtures of Bt and non-Bt varieties, 2) 12-row strips of Bt and non-Bt, 3) solid Bt, and 4) solid non-Bt. For both years cotton bollworm, Helicoverpa zea (Boddie), damage was less in solid Bt plots than strips and mixtures and all were less than solid non-Bt plots. Cotton fleahopper, Pseudatomoscelis seriatus (Reuter), damage was affected by refuge, but only in 2002 when damage was greater in solid Bt plots than all other plots and greater in strips than solid non-Bt plots. Abscissions were least in solid non-Bt plots, and less in mixtures and strips than solid Bt plots. In 2001, western flower thrips, Frankliniella occidentalis (Pergande), density was greatest in mixtures, whereas sweetpotato whitefly, Bemisia tabaci (Gennadius), was greatest in solid Bt plots, and greater in mixtures than solid non-Bt plots. Yield also was affected by refuge, it was greater for solid Bt plots than for solid non-Bt plots and mixtures in 2001, but the reverse was true in 2002.

  14. Competitive release of an agricultural insect pest: The case of stink bug outbreaks in transgenic Bt cotton in the southeast US

    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 ex...

  15. 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.

  16. 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.

  17. Heliocides as markers in selection of insect resistant cotton varieties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Development of insect resistance cotton varieities is an important goal in cotton genetics and in making selections in breeding programs. Presently, the use of genetically modified cottons containing Bt genes derived from the soil bacterium Bacillus thurengensis, are extensively utilized. An alter...

  18. Predicting the potential geographic distribution of cotton mealybug Phenacoccus solenopsis in India based on MAXENT ecological niche model.

    PubMed

    Fand, Babasaheb B; Kumar, Mahesh; Kamble, Ankush L

    2014-09-01

    Mealybug, Phenacoccus solenopsis Tinsley has recently emerged as a serious insect pest of cotton in India. This study demonstrates the use of Maxent algorithm for modeling the potential geographic distribution of P. solenopsis in India with presence-only data. Predictions were made based on the analysis of the relationship between 111 occurrence records for P. solenopsis and the corresponding current and future climate data defined on the study area. The climate data from worldclim database for current (1950-2000) and future (SRES A2 emission scenario for 2050) conditions were used. DIVA-GIS, an open source software for conducting spatial analysis was used for mapping the predictions from Maxent. The algorithm provided reasonable estimates of the species range indicating better discrimination of suitable and unsuitable areas for its occurrence in India under both present and future climatic conditions. The fit for the model as measured by AUC was high, with value of 0.930 for the training data and 0.895 for the test data, indicating the high level of discriminatory power for the Maxent. A Jackknife test for variable importance indicated that mean temperature of coldest quarter with highest gain value was the most important environmental variable determining the potential geographic distribution of P. solenopsis. The approaches used for delineating the ecological niche and prediction of potential geographic distribution are described briefly. Possible applications and limitations of the present modeling approach in future research and as a decision making tool in integrated pest management are discussed.

  19. Risk assessment and ecological effects of transgenic Bacillus thuringiensis crops on non-target organisms.

    PubMed

    Yu, Hui-Lin; Li, Yun-He; Wu, Kong-Ming

    2011-07-01

    The application of recombinant DNA technology has resulted in many insect-resistant varieties by genetic engineering (GE). Crops expressing Cry toxins derived from Bacillus thuringiensis (Bt) have been planted worldwide, and are an effective tool for pest control. However, one ecological concern regarding the potential effects of insect-resistant GE plants on non-target organisms (NTOs) has been continually debated. In the present study, we briefly summarize the data regarding the development and commercial use of transgenic Bt varieties, elaborate on the procedure and methods for assessing the non-target effects of insect-resistant GE plants, and synthetically analyze the related research results, mostly those published between 2005 and 2010. A mass of laboratory and field studies have shown that the currently available Bt crops have no direct detrimental effects on NTOs due to their narrow spectrum of activity, and Bt crops are increasing the abundance of some beneficial insects and improving the natural control of specific pests. The use of Bt crops, such as Bt maize and Bt cotton, results in significant reductions of insecticide application and clear benefits on the environment and farmer health. Consequently, Bt crops can be a useful component of integrated pest management systems to protect the crop from targeted pests.

  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.

  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. Large-scale test of the natural refuge strategy for delaying insect resistance to transgenic Bt crops.

    PubMed

    Jin, Lin; Zhang, Haonan; Lu, Yanhui; Yang, Yihua; Wu, Kongming; Tabashnik, Bruce E; Wu, Yidong

    2015-02-01

    The 'natural refuge strategy" for delaying insect resistance to transgenic cotton that produces insecticidal proteins from Bacillus thuringiensis (Bt) relies on refuges of host plants other than cotton that do not make Bt toxins. We tested this widely adopted strategy by comparing predictions from modeling with data from a four-year field study of cotton bollworm (Helicoverpa armigera) resistance to transgenic cotton producing Bt toxin Cry1Ac in six provinces of northern China. Bioassay data revealed that the percentage of resistant insects increased from 0.93% in 2010 to 5.5% in 2013. Modeling predicted that the percentage of resistant insects would exceed 98% in 2013 without natural refuges, but would increase to only 1.1% if natural refuges were as effective as non-Bt cotton refuges. Therefore, the results imply that natural refuges delayed resistance, but were not as effective as an equivalent area of non-Bt cotton refuges. The percentage of resistant insects with nonrecessive inheritance of resistance increased from 37% in 2010 to 84% in 2013. Switching to Bt cotton producing two or more toxins and integrating other control tactics could slow further increases in resistance.

  4. Large-Scale Evaluation of Association Between Pheromone Trap Captures and Cotton Boll Infestation for Pink Bollworm (Lepidoptera: Gelechiidae).

    PubMed

    Carrière, Yves; Antilla, Larry; Liesner, Leighton; Tabashnik, Bruce E

    2017-03-16

    Although transgenic cotton producing insecticidal proteins from Bacillus thuringiensis (Bt) is a cornerstone for pink bollworm control in some countries, integrated pest management remains important for bolstering sustainability of Bt cotton and is critical for controlling pink bollworm where Bt cotton is not available or where this pest has evolved resistance to Bt cotton. Here, we used data on moth captures in gossyplure-baited pheromone traps and boll infestations for 163 Bt and 152 non-Bt cotton fields from Arizona to evaluate accuracy of chemical control decisions relying on moth trapping data and capacity of Bt cotton to suppress survival of offspring produced by moths. Assuming an economic injury level of 12% boll infestation, the accuracy of decisions based on moth captures corresponding to economic thresholds of 6%, 8%, and 10% boll infestation increased from 44.7% to 67.1%. The association between moth captures and boll infestation was positive and significant for non-Bt cotton fields but was not significant for Bt cotton fields. Although chemical control decisions based on trapping data were only moderately accurate, pheromone traps could still be valuable for determining when moth populations are high enough to trigger boll sampling to more rigorously evaluate the need for insecticide sprays.

  5. 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.

  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. 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.

  8. Statement on Bt10

    EPA Pesticide Factsheets

    The United States Environmental Protection Agency regulates pesticidal substances produced in plants and the genetic material necessary for the plant to make those substances. This page describes the review and status of Bt 10.

  9. 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...

  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. [Effects of transgenic Bt crops on non-target soil animals].

    PubMed

    Yuan, Yi-gang; Ge, Feng

    2010-05-01

    Transgenic Bt crops are widely planted around the world. With the quick development and extension of genetically modified crops, it is needed to make a deep study on the effects of Bt crops on soil ecosystem. This paper reviewed the research progress on the effects of transgenic Bt crops on the population dynamics and community structure of soil animals, e.g., earthworm, nematode, springtail, mite, and beetle, etc. The development history of Bt crops was introduced, the passway the Bt protein comes into soil as well as the residual and degradation of Bt protein in soil were analyzed, and the critical research fields about the ecological risk analysis of transgenic Bt crops on non-target soil animals in the future were approached, which would provide a reference for the research of the effects of transgenic Bt crops on non-target soil animals.

  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. 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.…

  14. Review: biosafety assessment of Bt rice and other Bt crops using spiders as example for non-target arthropods in China.

    PubMed

    Yang, Huilin; Peng, Yuande; Tian, Jianxiang; Wang, Juan; Hu, Jilin; Song, Qisheng; Wang, Zhi

    2017-04-01

    Since the birth of transgenic crops expressing Bacillus thuringiensis (Bt) toxin for pest control, the public debate regarding ecological and environmental risks as well as benefits of Bt crops has continued unabated. The impact of Bt crops, especially on non-target invertebrates, has received particular attention. In this review, we summarize and analyze evidences for non-target effects of Bt rice on spiders, major predators in rice fields. Bt rice has been genetically modified to express the Bt protein, which has been shown to be transferred and accumulate in spiders as part of their food chain. Moreover, the Bt protein exhibits unintended effects on the physiology of spiders and spreads to higher trophic levels. Spiders possess unique physiological and ecological characteristics, revealing traits of surrogate species, and are thus considered to be excellent non-target arthropod model systems for study of Bt protein impacts. Due to the complexities of Bt protein transfer and accumulation mechanisms, as well as the apparent lack of information about resulting physiological, biochemical, and ecological effects on spiders, we raise questions and provide recommendations for promising further research.

  15. Nutrition affects insect susceptibility to Bt toxins

    NASA Astrophysics Data System (ADS)

    Deans, Carrie A.; Behmer, Spencer T.; Tessnow, Ashley E.; Tamez-Guerra, Patricia; Pusztai-Carey, Marianne; Sword, Gregory A.

    2017-01-01

    Pesticide resistance represents a major challenge to global food production. The spread of resistance alleles is the primary explanation for observations of reduced pesticide efficacy over time, but the potential for gene-by-environment interactions (plasticity) to mediate susceptibility has largely been overlooked. Here we show that nutrition is an environmental factor that affects susceptibility to Bt toxins. Protein and carbohydrates are two key macronutrients for insect herbivores, and the polyphagous pest Helicoverpa zea self-selects and performs best on diets that are protein-biased relative to carbohydrates. Despite this, most Bt bioassays employ carbohydrate-biased rearing diets. This study explored the effect of diet protein-carbohydrate content on H. zea susceptibility to Cry1Ac, a common Bt endotoxin. We detected a 100-fold increase in LC50 for larvae on optimal versus carbohydrate-biased diets, and significant diet-mediated variation in survival and performance when challenged with Cry1Ac. Our results suggest that Bt resistance bioassays that use ecologically- and physiologically-mismatched diets over-estimate susceptibility and under-estimate resistance.

  16. Nutrition affects insect susceptibility to Bt toxins

    PubMed Central

    Deans, Carrie A.; Behmer, Spencer T.; Tessnow, Ashley E.; Tamez-Guerra, Patricia; Pusztai-Carey, Marianne; Sword, Gregory A.

    2017-01-01

    Pesticide resistance represents a major challenge to global food production. The spread of resistance alleles is the primary explanation for observations of reduced pesticide efficacy over time, but the potential for gene-by-environment interactions (plasticity) to mediate susceptibility has largely been overlooked. Here we show that nutrition is an environmental factor that affects susceptibility to Bt toxins. Protein and carbohydrates are two key macronutrients for insect herbivores, and the polyphagous pest Helicoverpa zea self-selects and performs best on diets that are protein-biased relative to carbohydrates. Despite this, most Bt bioassays employ carbohydrate-biased rearing diets. This study explored the effect of diet protein-carbohydrate content on H. zea susceptibility to Cry1Ac, a common Bt endotoxin. We detected a 100-fold increase in LC50 for larvae on optimal versus carbohydrate-biased diets, and significant diet-mediated variation in survival and performance when challenged with Cry1Ac. Our results suggest that Bt resistance bioassays that use ecologically- and physiologically-mismatched diets over-estimate susceptibility and under-estimate resistance. PMID:28045087

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

    PubMed

    Ives, Anthony R; Paull, Cate; Hulthen, Andrew; Downes, Sharon; Andow, David A; Haygood, Ralph; Zalucki, Myron P; Schellhorn, Nancy A

    2017-01-01

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

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

    PubMed Central

    Ives, Anthony R.; Paull, Cate; Hulthen, Andrew; Downes, Sharon; Andow, David A.; Haygood, Ralph; Zalucki, Myron P.; Schellhorn, Nancy A.

    2017-01-01

    Transgenic crops that express insecticide genes from Bacillus thuringiensis (Bt) are used worldwide against moth and beetle pests. Because these engineered plants can kill over 95% of susceptible larvae, they can rapidly select for resistance. Here, we use a model for a pyramid two-toxin Bt crop to explore the consequences of spatio-temporal variation in the area of Bt crop and non-Bt refuge habitat. We show that variability over time in the proportion of suitable non-Bt breeding habitat, Q, or in the total area of Bt and suitable non-Bt habitat, K, can increase the overall rate of resistance evolution by causing short-term surges of intense selection. These surges can be exacerbated when temporal variation in Q and/or K cause high larval densities in refuges that increase density-dependent mortality; this will give resistant larvae in Bt fields a relative advantage over susceptible larvae that largely depend on refuges. We address the effects of spatio-temporal variation in a management setting for two bollworm pests of cotton, Helicoverpa armigera and H. punctigera, and field data on landscape crop distributions from Australia. Even a small proportion of Bt fields available to egg-laying females when refuges are sparse may result in high exposure to Bt for just a single generation per year and cause a surge in selection. Therefore, rapid resistance evolution can occur when Bt crops are rare rather than common in the landscape. These results highlight the need to understand spatio-temporal fluctuations in the landscape composition of Bt crops and non-Bt habitats in order to design effective resistance management strategies. PMID:28046073

  19. Field-evolved insect resistance to Bt crops: definition, theory, and data.

    PubMed

    Tabashnik, Bruce E; Van Rensburg, J B J; Carrière, Yves

    2009-12-01

    Transgenic crops producing Bacillus thuringiensis (Bt) toxins for insect pest control have been successful, but their efficacy is reduced when pests evolve resistance. Here we review the definition of field-evolved resistance, the relationship between resistance and field control problems, the theory underlying strategies for delaying resistance, and resistance monitoring methods. We also analyze resistance monitoring data from five continents reported in 41 studies that evaluate responses of field populations of 11 lepidopteran pests to four Bt toxins produced by Bt corn and cotton. After more than a decade since initial commercialization of Bt crops, most target pest populations remain susceptible, whereas field-evolved resistance has been documented in some populations of three noctuid moth species: Spodoptera frugiperda (J. E. Smith) to Cry1F in Bt corn in Puerto Rico, Busseola fusca (Fuller) to CrylAb in Bt corn in South Africa, and Helicoverpa zea (Boddie) to CrylAc and Cry2Ab in Bt cotton in the southeastern United States. Field outcomes are consistent with predictions from theory, suggesting that factors delaying resistance include recessive inheritance of resistance, abundant refuges of non-Bt host plants, and two-toxin Bt crops deployed separately from one-toxin Bt crops. The insights gained from systematic analyses of resistance monitoring data may help to enhance the durability of transgenic insecticidal crops. We recommend continued use of the longstanding definition of resistance cited here and encourage discussions about which regulatory actions, if any, should be triggered by specific data on the magnitude, distribution, and impact of field-evolved resistance.

  20. Bt maize and integrated pest management--a European perspective.

    PubMed

    Meissle, Michael; Romeis, Jörg; Bigler, Franz

    2011-09-01

    The European corn borer (Ostrinia nubilalis), the Mediterranean corn borer (Sesamia nonagrioides) and the western corn rootworm (Diabrotica virgifera virgifera) are the main arthropod pests in European maize production. Practised pest control includes chemical control, biological control and cultural control such as ploughing and crop rotation. A pest control option that is available since 1996 is maize varieties that are genetically engineered (GE) to produce insecticidal compounds. GE maize varieties available today express one or several genes from Bacillus thuringiensis (Bt) that target corn borers or corn rootworms. Incentives to growing Bt maize are simplified farm operations, high pest control efficiency, improved grain quality and ecological benefits. Limitations include the risk of resistance evolution in target pest populations, risk of secondary pest outbreaks and increased administration to comply with licence agreements. Growers willing to plant Bt maize in the European Union (EU) often face the problem that authorisation is denied. Only one Bt maize transformation event (MON810) is currently authorised for commercial cultivation, and some national authorities have banned cultivation. Spain is the only EU member state where Bt maize adoption levels are currently delivering farm income gains near full potential levels. In an integrated pest management (IPM) context, Bt maize can be regarded as a preventive (host plant resistance) or a responsive pest control measure. In any case, Bt maize is a highly specific tool that efficiently controls the main pests and allows combination with other preventive or responsive measures to solve other agricultural problems including those with secondary pests.

  1. 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, ...

  2. Modeling the invasion of recessive Bt-resistant insects: an impact on transgenic plants.

    PubMed

    Medvinsky, Alexander B; Morozov, Andrew Y; Velkov, Vassili V; Li, Bai-Lian; Sokolov, Mikhail S; Malchow, Horst

    2004-11-07

    There is a growing public concern on ecological and evolutionary consequence of the use of genetically modified organisms. We study the impact of Bt-resistant pests on genetically modified Bt crops. We develop and analyse a conceptual reaction-diffusion model of the Bt crop-Bt-susceptible insects-Bt-resistant insects to simulate the invasion of Bt-resistant insects. We show by means of computer simulations that there is a key parameter, which we define as the growth number that characterizes the insects' fitness. We also show that the Bt-resistant insect invasion can lead to inhomogeneity in plant and insect spatial distributions. The plant biomass is found to be essentially dependent on the duration of the Bt-resistant insect reproduction period. There are two types of this dependence. One of them exhibits, respectively, higher plant biomass in comparison with another. The ambiguity in the response of the Bt crop-Bt-susceptible insects system to the invasion of Bt-resistant insects can lead to serious complications in attempts to regulate the dynamics of the system.

  3. The design and implementation of insect resistance management programs for Bt crops.

    PubMed

    Head, Graham P; Greenplate, John

    2012-01-01

    Cotton and corn plants with insect resistance traits introduced through biotechnological methods and derived from the bacterium Bacillus thuringiensis (Bt) have been widely adopted since they were first introduced in 1996. Because of concerns about resistance evolving to these Bt crops, they have been released with associated IRM programs that employ multiple components and reflect the input of academic, industrial and regulatory experts. This paper summarizes the current status of Bt crop technologies in cotton and corn, the principles of IRM for Bt crops and what they mean for the design of IRM programs. It describes how these IRM programs have been implemented and some of the key factors affecting successful implementation. Finally, it suggests how they may evolve to properly steward these traits in different geographies around the world. The limited number of reported cases of resistance after more than 15 years of intensive global use of Bt crops suggest that this exercise has been broadly successful. Where resistance issues have been observed, they have been associated with first generation technologies and incomplete or compromised IRM programs (i.e., inadequate structured refuge). Next generation technologies with multiple pyramided modes of action, together with the implementation of IRM strategies that are more dependent upon manufacturing and less dependent upon grower behavior, such as seed mixes, should further enhance IRM programs for Bt crops.

  4. 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.

  5. 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 ...

  6. 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.

  7. Transgenic cotton expressing Cry10Aa toxin confers high resistance to the cotton boll weevil.

    PubMed

    Ribeiro, Thuanne Pires; Arraes, Fabricio Barbosa Monteiro; Lourenço-Tessutti, Isabela Tristan; Silva, Marilia Santos; Lisei-de-Sá, Maria Eugênia; Lucena, Wagner Alexandre; Macedo, Leonardo Lima Pepino; Lima, Janaina Nascimento; Santos Amorim, Regina Maria; Artico, Sinara; Alves-Ferreira, Márcio; Mattar Silva, Maria Cristina; Grossi-de-Sa, Maria Fatima

    2017-01-12

    Genetically modified (GM) cotton plants that effectively control cotton boll weevil (CBW), which is the most destructive cotton insect pest in South America, are reported here for the first time. This work presents the successful development of a new GM cotton with high resistance to CBW conferred by Cry10Aa toxin, a protein encoded by entomopathogenic Bacillus thuringiensis (Bt) gene. The plant transformation vector harbouring cry10Aa gene driven by the cotton ubiquitination-related promoter uceA1.7 was introduced into a Brazilian cotton cultivar by biolistic transformation. Quantitative PCR (qPCR) assays revealed high transcription levels of cry10Aa in both T0 GM cotton leaf and flower bud tissues. Southern blot and qPCR-based 2(-ΔΔCt) analyses revealed that T0 GM plants had either one or two transgene copies. Quantitative and qualitative analyses of Cry10Aa protein expression showed variable protein expression levels in both flower buds and leaves tissues of T0 GM cotton plants, ranging from approximately 3.0 to 14.0 μg g(-1) fresh tissue. CBW susceptibility bioassays, performed by feeding adults and larvae with T0 GM cotton leaves and flower buds, respectively, demonstrated a significant entomotoxic effect and a high level of CBW mortality (up to 100%). Molecular analysis revealed that transgene stability and entomotoxic effect to CBW were maintained in T1 generation as the Cry10Aa toxin expression levels remained high in both tissues, ranging from 4.05 to 19.57 μg g(-1) fresh tissue, and the CBW mortality rate remained around 100%. In conclusion, these Cry10Aa GM cotton plants represent a great advance in the control of the devastating CBW insect pest and can substantially impact cotton agribusiness.

  8. 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

  9. 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…

  10. Similar genetic basis of resistance to Bt toxin Cry1Ac in Boll-selected and diet-selected strains of pink bollworm.

    PubMed

    Fabrick, Jeffrey A; Tabashnik, Bruce E

    2012-01-01

    Genetically engineered cotton and corn plants producing insecticidal Bacillus thuringiensis (Bt) toxins kill some key insect pests. Yet, evolution of resistance by pests threatens long-term insect control by these transgenic Bt crops. We compared the genetic basis of resistance to Bt toxin Cry1Ac in two independently derived, laboratory-selected strains of a major cotton pest, the pink bollworm (Pectinophora gossypiella [Saunders]). The Arizona pooled resistant strain (AZP-R) was started with pink bollworm from 10 field populations and selected with Cry1Ac in diet. The Bt4R resistant strain was started with a long-term susceptible laboratory strain and selected first with Bt cotton bolls and later with Cry1Ac in diet. Previous work showed that AZP-R had three recessive mutations (r1, r2, and r3) in the pink bollworm cadherin gene (PgCad1) linked with resistance to Cry1Ac and Bt cotton producing Cry1Ac. Here we report that inheritance of resistance to a diagnostic concentration of Cry1Ac was recessive in Bt4R. In interstrain complementation tests for allelism, F(1) progeny from crosses between AZP-R and Bt4R were resistant to Cry1Ac, indicating a shared resistance locus in the two strains. Molecular analysis of the Bt4R cadherin gene identified a novel 15-bp deletion (r4) predicted to cause the loss of five amino acids upstream of the Cry1Ac-binding region of the cadherin protein. Four recessive mutations in PgCad1 are now implicated in resistance in five different strains, showing that mutations in cadherin are the primary mechanism of resistance to Cry1Ac in laboratory-selected strains of pink bollworm from Arizona.

  11. 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, ...

  12. 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...

  13. 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...

  14. On risk and regulation: Bt crops in India

    PubMed Central

    Herring, Ronald J

    2014-01-01

    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

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

    PubMed

    Herring, Ronald J

    2014-07-03

    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.

  16. 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

  17. 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...

  18. 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

    2015-07-27

    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.

  19. Variation among conventional cultivars could be used as a criterion for environmental safety assessment of Bt rice on nontarget arthropods

    NASA Astrophysics Data System (ADS)

    Wang, Fang; Dang, Cong; Chang, Xuefei; Tian, Junce; Lu, Zengbin; Chen, Yang; Ye, Gongyin

    2017-02-01

    The current difficulty facing risk evaluations of Bacillus thuringiensis (Bt) crops on nontarget arthropods (NTAs) is the lack of criteria for determining what represents unacceptable risk. In this study, we investigated the biological parameters in the laboratory and field population abundance of Nilaparvata lugens (Hemiptera: Delphacidae) on two Bt rice lines and the non-Bt parent, together with 14 other conventional rice cultivars. Significant difference were found in nymphal duration and fecundity of N. lugens fed on Bt rice KMD2, as well as field population density on 12 October, compared with non-Bt parent. However, compared with the variation among conventional rice cultivars, the variation of each parameter between Bt rice and the non-Bt parent was much smaller, which can be easily seen from low-high bar graphs and also the coefficient of variation value (C.V). The variation among conventional cultivars is proposed to be used as a criterion for the safety assessment of Bt rice on NTAs, particularly when statistically significant differences in several parameters are found between Bt rice and its non-Bt parent. Coefficient of variation is suggested as a promising parameter for ecological risk judgement of IRGM rice on NTAs.

  20. Variation among conventional cultivars could be used as a criterion for environmental safety assessment of Bt rice on nontarget arthropods

    PubMed Central

    Wang, Fang; Dang, Cong; Chang, Xuefei; Tian, Junce; Lu, Zengbin; Chen, Yang; Ye, Gongyin

    2017-01-01

    The current difficulty facing risk evaluations of Bacillus thuringiensis (Bt) crops on nontarget arthropods (NTAs) is the lack of criteria for determining what represents unacceptable risk. In this study, we investigated the biological parameters in the laboratory and field population abundance of Nilaparvata lugens (Hemiptera: Delphacidae) on two Bt rice lines and the non-Bt parent, together with 14 other conventional rice cultivars. Significant difference were found in nymphal duration and fecundity of N. lugens fed on Bt rice KMD2, as well as field population density on 12 October, compared with non-Bt parent. However, compared with the variation among conventional rice cultivars, the variation of each parameter between Bt rice and the non-Bt parent was much smaller, which can be easily seen from low-high bar graphs and also the coefficient of variation value (C.V). The variation among conventional cultivars is proposed to be used as a criterion for the safety assessment of Bt rice on NTAs, particularly when statistically significant differences in several parameters are found between Bt rice and its non-Bt parent. Coefficient of variation is suggested as a promising parameter for ecological risk judgement of IRGM rice on NTAs. PMID:28167821

  1. Vip3Aa tolerance response of Helicoverpa armigera populations from a Cry1Ac cotton planting region.

    PubMed

    An, Jingjie; Gao, Yulin; Wu, Kongming; Gould, Fred; Gao, Jianhua; Shen, Zhicheng; Lei, Chaoliang

    2010-12-01

    Transgenic cotton, Gossypium hirsutum L., that expresses the Bacillus thuringiensis (Bt) Cry1Ac toxin, holds great promise in controlling target insect pests. Evolution of resistance by target pests is the primary threat to the continued efficacy of Bt cotton. To thwart pest resistance evolution, a transgenic cotton culitvar that produces two different Bt toxins, cry1Ac and vip3A genes, was proposed as a successor of cry1Ac cotton. This article reports on levels of Vip3Aa tolerance in Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) populations from the Cry1Ac cotton planting region in China based on bioassays of the F1 generation of isofemale lines. In total, 80 isofemale families of H. armigera from Xiajin county of Shandong Province (an intensive Bt cotton planting area) and 93 families from Anci county of Hebei Province (a multiple-crop system including corn [Zea mays L.] , soybean [Glycine max (L.) Merr.], peanut (Arachis hypogaea L.), and Bt cotton) were screened with a discriminating concentration of both Cry1Ac- and Vip3A-containing diets in 2009. From data on the relative average development rates and percentage of larval weight inhibition of F1 full-sib families tested simultaneously on Cry1Ac and Vip3Aa, results indicate that responses to Cry1Ac and Vip3Aa were not genetically correlated in field population ofH. armigera. This indicates that the threat of cross-resistance between Cry1Ac and Vip3A is low in field populations of H. armigera. Thus, the introduction of Vip3Aa/Cry1Ac-producing lines could delay resistance evolution in H. armigera in Bt cotton planting area of China.

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

    2016-02-02

    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.

  8. 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.

  9. 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

    2016-07-18

    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.

  10. 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

  11. 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.

  12. 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

  13. Heterosis and correlation in interspecific and intraspecific hybrids of cotton.

    PubMed

    Munir, S; Hussain, S B; Manzoor, H; Quereshi, M K; Zubair, M; Nouman, W; Shehzad, A N; Rasul, S; Manzoor, S A

    2016-06-24

    Interspecific and intraspecific hybrids show varying degrees of heterosis for yield and yield components. Yield-component traits have complex genetic relationships with each other. To determine the relationship of yield-component traits and fiber traits with seed cotton yield, six lines (Bt. CIM-599, CIM-573, MNH-786, CIM-554, BH-167, and GIZA-7) and three test lines (MNH-886, V4, and CIM-557) were crossed in a line x tester mating design. Heterosis was observed for seed cotton yield, fiber traits, and for other yield-component traits. Heterosis in interspecific hybrids for seed cotton yield was more prominent than in intraspecific hybrids. The interspecific hybrid Giza-7 x MNH-886 had the highest heterosis (114.77), while among intraspecific hybrids, CIM-554 x CIM-557 had the highest heterosis (61.29) for seed cotton yield. A major trait contributing to seed cotton yield was bolls/plant followed by boll weight. Correlation studies revealed that bolls/plant, boll weight, lint weight/boll, lint index, seed index, lint/seed, staple length, and staple strength were significantly and positively associated with seed cotton yield. Selection based on boll weight, boll number, lint weight/boll, and lint index will be helpful for improving cotton seed yield.

  14. Impacts of Bt rice expressing Cry1C or Cry2A protein on the performance of nontarget leafhopper, Nephotettix cincticeps (Hemiptera: Cicadellidae), under laboratory and field conditions.

    PubMed

    Lu, Z B; Tian, J C; Wang, W; Xu, H X; Hu, C; Guo, Y Y; Peng, Y F; Ye, G Y

    2014-02-01

    Transgenic rice expressing Bacillus thuringiensis Berliner (Bt) protein can effectively control target insects including stem borers and leaf folders. However, the potential effects of Bt rice on nontarget organisms including nontarget herbivores have not been fully evaluated. In the current study, ecological fitness parameters of the nontarget herbivore, Nephotettix cincticeps (Uhler) (Hemiptera: Cicadellidae), fed on T1C-19 (Cry1C) or T2A-1 (Cry2A) rice were compared with non-Bt rice (MH63) under laboratory conditions. A 2-yr field trial was also conducted to monitor the population dynamics of N. cincticeps in the Bt and control rice plots using the vacuum-suction machine and yellow sticky card traps. Laboratory results showed that there were no significant differences in some of biological parameters including egg developmental duration, adult fresh weight, adult longevity, and oviposition period when N. cincticeps fed on Bt or non-Bt rice was compared. However, the survival rate of N. cincticeps nymphs fed on T2A-1 Bt rice plants was significantly higher than that on the control. When N. cincticeps fed on T1C-19 Bt rice plants, its nymphal duration was significantly longer and fecundity significantly lower compared with those fed on both T2A-1 Bt and non-Bt rice plants; the preoviposition period of N. cincticeps fed on T1C-19 and T2A-1 Bt rice was also significantly shorter than those on non-Bt rice. Nonetheless, both seasonal density and population dynamics of N. cincticeps adults and nymphs were similar between Bt (T1C-19 and T2A-1) and non-Bt rice plots under field conditions. In conclusion, our results indicate that our two tested Bt rice lines would not lead to higher population of N. cincticeps. Long-term experiments to monitor the population dynamics of N. cincticeps at large scale need to be carried out to confirm the current results.

  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. Insect resistance management for Syngenta's VipCot transgenic cotton.

    PubMed

    Kurtz, Ryan W; McCaffery, Alan; O'Reilly, David

    2007-07-01

    Syngenta is seeking commercial registration for VipCot cotton, a pyramided transgenic cotton trait that expresses two insecticidal proteins derived from Bacillus thuringiensis Vip3A and Cry1Ab. Both proteins are highly effective against two key cotton pests, Helicoverpa zea cotton bollworm; and Heliothis virescens, tobacco budworm. To investigate the role of VipCot cotton in delaying the development of resistance in these pests to transgenic Bt traits, Syngenta has performed studies to determine the dose of proteins expressed in VipCot and evaluate the potential for cross-resistance between the component proteins. Following United States Environmental Protection Agency (US EPA) high dose methods 1 and 4, VipCot was shown to express a high dose of proteins for H. zea and H. virescens. VipCot was also confirmed to express a high dose of proteins for H. zea through US EPA Method 5. Additionally, all the data collected to date verify a lack of cross-resistance between Vip3A and Cry proteins. These two key pieces of information indicate that VipCot cotton should be very durable under the currently mandated high dose plus refuge insect resistance management strategy.

  19. 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 ...

  20. Seed cotton unloading systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this article was to review the literature and describe the current technology used by U.S. cotton gins for seed cotton unloading. Unloading systems supply the gin with raw material. Their essential functions are 1) to remove non-cotton materials such as protective covers used duri...

  1. Long-term regional suppression of pink bollworm by Bacillus thuringiensis cotton

    PubMed Central

    Carrière, Yves; Ellers-Kirk, Christa; Sisterson, Mark; Antilla, Larry; Whitlow, Mike; Dennehy, Timothy J.; Tabashnik, Bruce E.

    2003-01-01

    Despite the potentially profound impact of genetically modified crops on agriculture and the environment, we know little about their long-term effects. Transgenic crops that produce toxins from Bacillus thuringiensis (Bt) to control insects are grown widely, but rapid evolution of resistance by pests could nullify their benefits. Here, we present theoretical analyses showing that long-term suppression of pest populations is governed by interactions among reproductive rate, dispersal propensity, and regional abundance of a Bt crop. Supporting this theory, a 10-year study in 15 regions across Arizona shows that Bt cotton suppressed a major pest, pink bollworm (Pectinophora gossypiella), independent of demographic effects of weather and variation among regions. Pink bollworm population density declined only in regions where Bt cotton was abundant. Such long-term suppression has not been observed with insecticide sprays, showing that transgenic crops open new avenues for pest control. The debate about putative benefits of Bt crops has focused primarily on short-term decreases in insecticide use. The present findings suggest that long-term regional pest suppression after deployment of Bt crops may also contribute to reducing the need for insecticide sprays. PMID:12571355

  2. Transgenic cotton expressing synthesized scorpion insect toxin AaHIT gene confers enhanced resistance to cotton bollworm (Heliothis armigera) larvae.

    PubMed

    Wu, Jiahe; Luo, Xiaoli; Wang, Zhian; Tian, Yingchuan; Liang, Aihua; Sun, Yi

    2008-03-01

    A synthetic scorpion Hector Insect Toxin (AaHIT) gene, under the control of a CaMV35S promoter, was cloned into cotton via Agrobacterium tumefaciens-mediated transformation. Southern blot analyses indicated that integration of the transgene varied from one to more than three estimated copies per genome; seven homozygous transgenic lines with one copy of the T-DNA insert were then selected by PCR and Southern blot analysis. AaHIT expression was from 0.02 to 0.43% of total soluble protein determined by western blot. These homozygous transgenic lines killed larvae of cotton bollworm (Heliothis armigera) by 44-98%. The AaHIT gene could used therefore an alternative to Bt toxin and proteinase inhibitor genes for producing transgenic cotton crops with effective control of bollworm.

  3. Bt crops producing Cry1Ac, Cry2Ab and Cry1F do not harm the green lacewing, Chrysoperla rufilabris.

    PubMed

    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.

  4. 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...

  5. A comparison of spider communities in Bt and non-Bt rice fields.

    PubMed

    Lee, Sue Yeon; Kim, Seung Tae; Jung, Jong Kook; Lee, Joon-Ho

    2014-06-01

    To assess the potential adverse effects of a Bt rice line (Japonica rice cultivar, Nakdong) expressing a synthetic cry1Ac1 gene, C7-1-9-1-B, which was highly active against all larval stages of Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Crambidae), we investigated the community structure of spiders in Bt and non-Bt rice fields during the rice-growing season in 2007 and 2008 in Chungcheongnam-do, Korea. Spiders were surveyed with a sweep net and suction device. Suction sampling captured more spiders, measured in terms of species level and abundance, than sweeping. Araneidae and Thomisidae were captured more by sweeping, and certain species were captured only by sweeping. These findings show that both suction and sweep sampling methods should be used because these methods are most likely complementary. In total, 29 species in 23 genera and nine families were identified from the 4,937 spiders collected, and both Bt and non-Bt rice fields showed a typical Korean spider assemblage. The temporal patterns of spider species richness and spider abundance were very similar between Bt and non-Bt rice, although significant differences in species richness were observed on a few occasions. Overall, spider community structure, including diversity, the dominant species, and abundance did not differ between Bt and non-Bt rice. The results of the study indicated that the transgenic Cry1Ac rice lines tested in this study had no adverse effects on the spider community structure of the rice fields.

  6. Construction of a standard reference plasmid containing seven target genes for the detection of transgenic cotton.

    PubMed

    Wang, Xujing; Tang, Qiaoling; Dong, Lei; Dong, Yufeng; Su, Yueyan; Jia, Shirong; Wang, Zhixing

    2014-07-01

    Insect resistance and herbicide tolerance are the dominant traits of commercialized transgenic cotton. In this study, we constructed a general standard reference plasmid for transgenic cotton detection. Target genes, including the cowpea trypsin gene cptI, the insect resistance gene cry1Ab/1Ac, the herbicide tolerance gene cp4-epsps, the Agrobacterium tumefaciens nopaline synthase (Nos) terminator that exists in transgenic cotton and part of the endogenous cotton SadI gene were amplified from plasmids pCPT1, pBT, pCP4 and pBI121 and from DNA of the nontransgenic cotton line K312, respectively. The genes cry1Ab/1Ac and cptI, as well as cp4-epsps and the Nos terminator gene, were ligated together to form the fusion genes cptI-Bt and cp4-Nos, respectively, by overlapping PCR. We checked the validity of genes Sad1, cptI-Bt and cp4-Nos by DNA sequencing. Then, positive clones of cptI-Bt, cp4-Nos and Sad1 were digested with the corresponding restriction enzymes and ligated sequentially into vector pCamBIA2300, which contains the CAMV 35S promoter and nptII gene, to form the reference plasmid pMCS. Qualitative detection showed that pMCS is a good positive control for transgenic cotton detection. Real-time PCR detection efficiencies with pMCS as a calibrator ranged from 94.35% to 98.67% for the standard curves of the target genes (R(2)⩾0.998). The relative standard deviation of the mean value for the known sample was 11.95%. These results indicate that the strategy of using the pMCS plasmid as a reference material is feasible and reliable for the detection of transgenic cotton. Therefore, this plasmid can serve as a useful reference tool for qualitative and quantitative detection of single or stacked trait transgenic cotton, thus paving the way for the identification of various products containing components of transgenic cotton.

  7. 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...

  8. Long-term changes in the numbers of Helicoverpa punctigera (Lepidoptera: Noctuidae) in a cotton production landscape in northern New South Wales, Australia.

    PubMed

    Baker, G H; Tann, C R

    2017-04-01

    Two noctuid moths, Helicoverpa punctigera and Helicoverpa armigera, are pests of several agricultural crops in Australia, most notably cotton. Cotton is a summer crop, grown predominantly in eastern Australia. The use of transgenic (Bt) cotton has reduced the damage caused by Helicoverpa spp., but the development of Bt resistance in these insects remains a threat. In the past, large populations of H. punctigera have built up in inland Australia, following autumn-winter rains. Moths have then migrated to the cropping regions in spring, when their inland host plants dried off. To determine if there have been any long-term changes in this pattern, pheromone traps were set for H. punctigera throughout a cropping landscape in northern New South Wales from 1992 to 2015. At least three generations of moths were caught from spring to autumn. The 1st generation (mostly spring migrants) was the most numerous. Trap captures varied between sites and decreased in time, especially for moths in the 1st generation. Nearby habitat type influenced the size of catch and there was some evidence that local weather also influenced the numbers of moths caught. There was no correlation between trap catches in the cropping region and rainfall in the inland. In addition, there was little evidence that Bt cotton has reduced the abundance of H. punctigera at landscape scale. The apparent decline in the number of presumably Bt susceptible moths arriving each spring in the cropping regions from inland habitats is of concern in relation to the management of Bt resistance.

  9. Cannibalism of Helicoverpa zea (Lepidoptera: Noctuidae) from Bacillus thuringiensis (Bt) transgenic corn versus non-Bt corn.

    PubMed

    Chilcutt, Charles F

    2006-06-01

    Because of the importance of cannibalism in population regulation of Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) in corn, Zea mays L., it is useful to understand the interactions between Bacillus thuringiensis (Bt) transgenic corn and cannibalism. To determine the effects of Bt corn on cannibalism in H. zea, pairs of the same or different instars were taken from Bt or non-Bt corn and placed on artificial diet in proximity. Cannibalism occurred in 91% of pairs and was approximately 7% greater for pairs of larvae reared from Bt transgenic corn (95%) than from non-Bt corn (88%). Also, first instar by first instar pairs had a lower rate of cannibalism than other pairs. Time until cannibalism was not different for larvae from Bt corn versus non-Bt corn. Pupation rate of cannibals and surviving victims was not different for pairs from Bt corn versus non-Bt corn. Finally, cannibalism increased pupation rate of cannibals from both Bt and non-Bt corn by approximately 23 and 12%, respectively, although the increases were not significant. Thus, negative effects of Bt on larvae were compensated by increased cannibalism in comparison with larvae reared on non-Bt corn, which increased larval survival to levels comparable with larvae reared on non-Bt plants.

  10. 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

  11. Type of fitness cost influences the rate of evolution of resistance to transgenic Bt crops.

    PubMed

    Hackett, Sean C; Bonsall, Michael B

    2016-10-01

    The evolution of resistance to pesticides by insect pests is a significant challenge for sustainable agriculture. For transgenic crops expressing Bacillus thuringiensis (Bt), crystalline (Cry) toxins resistance evolution may be delayed by the high-dose/refuge strategy in which a non-toxic refuge is planted to promote the survival of susceptible insects. The high-dose/refuge strategy may interact with fitness costs associated with resistance alleles to further delay resistance. However, while a diverse range of fitness costs are reported in the field, they are typically represented as a fixed reduction in survival or viability which is insensitive to ecological conditions such as competition. Furthermore, the potential dynamic consequences of restricting susceptible insects to a refuge which represents only a fraction of the available space have rarely been considered.We present a generalized discrete time model which utilizes dynamic programming methods to derive the optimal management decisions for the control of a theoretical insect pest population exposed to Bt crops. We consider three genotypes (susceptible homozygotes, resistant homozygotes and heterozygotes) and implement fitness costs of resistance to Bt toxins as either a decrease in the relative competitive ability of resistant insects or as a penalty on fecundity. Model analysis is repeated and contrasted for two types of density dependence: uniform density dependence which operates equally across the landscape and heterogeneous density dependence where the intensity of competition scales inversely with patch size and is determined separately for the refuge and Bt crop.When the planting of Bt is decided optimally, fitness costs to fecundity allow for the planting of larger areas of Bt crops than equivalent fitness costs that reduce the competitive ability of resistant insects.Heterogeneous competition only influenced model predictions when the proportional area of Bt planted in each season was decided

  12. $1+ Cotton? New Thresholds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton is a major crop in Arizona and is affected by multiple insect pests. A highly effective and economically efficient integrated pest management program has been developed for the major pests of cotton. The program utilizes sampling to determine the abundance of pest insects in the field and eco...

  13. Keeping Cotton Green

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton is a major crop in Arizona and is affected by multiple insect pests. A highly effective and economically efficient integrated pest management program has been developed for the major pests of cotton. The program utilizes sampling to determine the abundance of pest insects in the field and eco...

  14. 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...

  15. No evidence for change in oviposition behaviour of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) after widespread adoption of transgenic insecticidal cotton.

    PubMed

    Zalucki, M P; Cunningham, J P; Downes, S; Ward, P; Lange, C; Meissle, M; Schellhorn, N A; Zalucki, J M

    2012-08-01

    Cotton growing landscapes in Australia have been dominated by dual-toxin transgenic Bt varieties since 2004. The cotton crop has thus effectively become a sink for the main target pest, Helicoverpa armigera. Theory predicts that there should be strong selection on female moths to avoid laying on such plants. We assessed oviposition, collected from two cotton-growing regions, by female moths when given a choice of tobacco, cotton and cabbage. Earlier work in the 1980s and 1990s on populations from the same geographic locations indicated these hosts were on average ranked as high, mid and low preference plants, respectively, and that host rankings had a heritable component. In the present study, we found no change in the relative ranking of hosts by females, with most eggs being laid on tobacco, then cotton and least on cabbage. As in earlier work, some females laid most eggs on cotton and aspects of oviposition behaviour had a heritable component. Certainly, cotton is not avoided as a host, and the implications of these finding for managing resistance to Bt cotton are discussed.

  16. 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

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. Effect of Bt broccoli and resistant genotype of Plutella xylostella (Lepidoptera: Plutellidae) on development and host acceptance of the parasitoid Diadegma insulare (Hymenoptera: Ichneumonidae).

    PubMed

    Liu, Xiaoxia; Chen, Mao; Onstad, David; Roush, Rick; Shelton, Anthony M

    2011-08-01

    The ecological implications on biological control of insecticidal transgenic plants, which produce crystal (Cry) proteins from the soil bacterium Bacillus thuringiensis (Bt), remain a contentious issue and affect risk assessment decisions. In this study, we used a unique system of resistant insects, Bt plants and a parasitoid to critically evaluate this issue. The effects of broccoli type (normal or expressing Cry1Ac protein) and insect genotype (susceptible or Cry1Ac-resistant) of Plutella xylostella L. (Lepidoptera: Plutellidae) were examined for their effects on the development and host foraging behavior of the parasitoid, Diadegma insulare (Cresson) (Hymenoptera: Ichneumonidae) over two generations. Parasitism rate and development of D. insulare were not significantly different when different genotypes (Bt-resistant or susceptible) of insect host larvae fed on non-Bt broccoli plants. D. insulare could not discriminate between resistant and susceptible genotypes of P. xylostella, nor between Bt and normal broccoli plants with different genotypes of P. xylostella feeding on them. No D. insulare could emerge from Bt broccoli-fed susceptible and heterozygous P. xylostella larvae because these larvae were unable to survive on Bt broccoli. The parasitism rate, developmental period, pupal and adult weights of D. insulare that had developed on Bt broccoli-fed Cry1Ac-resistant P. xylostella larvae were not significantly different from those that developed on non-Bt broccoli-fed larvae. Female D. insulare emerged from Cry1Ac-resistant P. xylostella that fed on Bt plants could successfully parasitize P. xylostella larvae. The life parameters of the subsequent generation of D. insulare from P. xylostella reared on Bt broccoli were not significantly different from those from non-Bt broccoli. The Cry1Ac protein was detected in P. xylostella and in D. insulare when hosts fed on Bt broccoli. These results are the first to indicate that Cry1Ac did not harm the development or

  2. 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...

  3. 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...

  4. 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...

  5. 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

  6. Development of Bt Rice and Bt Maize in China and Their Efficacy in Target Pest Control

    PubMed Central

    Liu, Qingsong; Hallerman, Eric; Peng, Yufa; Li, Yunhe

    2016-01-01

    Rice and maize are important cereal crops that serve as staple foods, feed, and industrial material in China. Multiple factors constrain the production of both crops, among which insect pests are an important one. Lepidopteran pests cause enormous yield losses for the crops annually. In order to control these pests, China plays an active role in development and application of genetic engineering (GE) to crops, and dozens of GE rice and GE maize lines expressing insecticidal proteins from the soil bacterium Bacillus thuringiensis (Bt) have been developed. Many lines have entered environmental release, field testing, and preproduction testing, and laboratory and field experiments have shown that most of the Bt rice and Bt maize lines developed in China exhibited effective control of major target lepidopteran pests on rice (Chilo suppressalis, Scirpophaga incertulas, and Cnaphalocrocis medinalis) and maize (Ostrinia furnacalis), demonstrating bright prospects for application. However, none of these Bt lines has yet been commercially planted through this writing in 2016. Challenges and perspectives for development and application of Bt rice and maize in China are discussed. This article provides a general context for colleagues to learn about research and development of Bt crops in China, and may shed light on future work in this field. PMID:27763554

  7. 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 ...

  8. 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.

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  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. Tradeoff between reproduction and resistance evolution to Bt-toxin in Helicoverpa armigera: regulated by vitellogenin gene expression.

    PubMed

    Zhang, W N; Xiao, H J; Liang, G M; Guo, Y Y; Wu, K M

    2014-08-01

    Evolution of resistance to insecticides usually has fitness tradeoffs associated with adaptation to the stress. The basic regulation mechanism of tradeoff between reproduction and resistance evolution to Bacillus thuringiensis (Bt) toxin in the cotton bollworm, Helicoverpa armigera (Ha), based on the vitellogenin (Vg) gene expression was analyzed here. The full-length cDNA of the Vg gene HaVg (JX504706) was cloned and identified. HaVg has 5704 base pairs (bp) with an open reading frame (ORF) of 5265 bp, which encoded 1756 amino acid protein with a predicted molecular mass of 197.28 kDa and a proposed isoelectric point of 8.74. Sequence alignment analysis indicated that the amino acid sequence of HaVg contained all of the conserved domains detected in the Vgs of the other insects and had a high similarity with the Vgs of the Lepidoptera insects, especially Noctuidae. The resistance level to Cry1Ac Bt toxin and relative HaVg mRNA expression levels among the following four groups: Cry1Ac-susceptible strain (96S), Cry1Ac-resistant strain fed on artificial diet with Bt toxin for 135 generations (BtR stands for the Cry1Ac Bt resistance), progeny of the Cry1Ac-resistant strain with a non-Bt-toxin artificial diet for 38 generations (CK1) and the direct descendants of the 135th-generation resistant larvae which were fed on an artificial diet without the Cry1Ac protein (CK2) were analyzed. Compared with the 96S strain, the resistance ratios of the BtR strain, the CK1 strain and the CK2 strain were 2917.15-, 2.15- and 2037.67-fold, respectively. The maximum relative HaVg mRNA expression levels of the BtR strain were approximately 50% less than that of the 96S strain, and the coming of maximum expression was delayed for approximately 4 days. The overall trend of the HaVg mRNA expression levels in the CK1 strain was similar to that in the 96S strain, and the overall trend of the HaVg mRNA expression levels in the CK2 strain was similar to that in the BtR strain. Our results

  16. 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.

  17. Effects of transgenic Cry1Ac + CpTI cotton on non-target mealybug pest Ferrisia virgata and its predator Cryptolaemus montrouzieri.

    PubMed

    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.

  18. 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

  19. 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

  20. 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.

  1. 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

  2. Nitenpyram, Dinotefuran, and Thiamethoxam Used as Seed Treatments Act as Efficient Controls against Aphis gossypii via High Residues in Cotton Leaves.

    PubMed

    Zhang, Zhengqun; Zhang, Xuefeng; Wang, Yao; Zhao, Yunhe; Lin, Jin; Liu, Feng; Mu, Wei

    2016-12-14

    The effects of eight neonicotinoid seed treatments against the cotton aphid Aphis gossypii and its natural enemies in Bt cotton fields were evaluated, and the concentrations of these neonicotinoids in cotton leaves and soil were also investigated. The results showed that all neonicotinoid seed treatments efficiently reduced A. gossypii populations throughout the cotton seedling stage. The percentages of curly leaf plants in all of the neonicotinoid seed treatments were below the threshold for economic loss. Among the eight tested neonicotinoid seed treatments, nitenpyram, dinotefuran, and thiamethoxam showed high control efficiency against A. gossypii. Residues of the three neonicotinoids were higher than those of other neonicotinoids in cotton leaves. Moreover, residues of dinotefuran and nitenpyram remained at low levels in the soil. However, the abundance of natural enemies in the cotton field was to some extent influenced by neonicotinoid seed treatments. Therefore, neonicotinoids nitenpyram, dinotefuran, and thiamethoxam used as seed treatment can provide effective protection that should play an important role in the management of early-season A. gossypii in Bt cotton fields; however, the risks of neonicotinoids to the environment should also be considered.

  3. 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...

  4. 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 ...

  5. Fusarium verticillioides and fumonisin contamination in Bt and non-Bt maize cultivated in Brazil.

    PubMed

    Barroso, Vinícius M; Rocha, Liliana O; Reis, Tatiana A; Reis, Gabriela M; Duarte, Aildson P; Michelotto, Marcos D; Correa, Benedito

    2017-03-06

    Fusarium verticillioides is one of the main pathogens of maize, causing ear and stalk rots. This fungus is also able to produce high levels of fumonisins, which have been linked to various illnesses in humans and animals. Previous studies have shown that maize hybrids genetically modified with the cry genes from the bacterium Bacillus thuringiensis (Bt) presented lower incidence of F. verticillioides and fumonisin levels, presumably through the reduction of insects, which could act as vectors of fungi. The aim of this study was to assess the incidence of F. verticillioides and the concentration of fumonisins in Bt and isogenic non-Bt hybrids (2B710Hx, 30F35YG, 2B710, and 30F35, respectively). The samples of 2B710Hx and 30F35YG presented lower F. verticillioides frequency than 2B710 and 30F35 samples. However, there was no statistical difference between fumonisin contamination when Bt and non-Bt samples were compared (P > 0.05). The results suggest that other environmental parameters could possibly trigger fumonisin production during plant development in the field; consequently, other management strategies should be applied to aid controlling fumonisin contamination in maize.

  6. 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

  7. 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.

  8. 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...

  9. Decreased whorl and ear damage in nine mon810 Bacillus thuringiensis (Bt)-transgenic corn hybrids compared with their non-Bt counterparts.

    PubMed

    Chilcutt, Charles F; Odvody, Gary N; Correa, J Carlos; Remmers, Jeff; Parker, Roy D

    2006-12-01

    We examined nine pairs of near-isogenic hybrids of Bacillus thuringiensis (Bt) and non-Bt corn, Zea mays L., at two locations in 1999 and three locations in 2000 to compare the effects of Bt toxins on damage caused by Helicoverpa zea (Boddie) to whorl stage field corn, and ear damage at harvest, as well as yield. We found that whorl damage was less in all Bt hybrids compared with their non-Bt counterparts each year and at each location. Differences in ear damage between Bt and non-Bt hybrids, however, differed in 1999 and 2000. In 1999, only one Bt hybrid, NC+5788Bt, had less ear damage than its non-Bt counterpart at the dryland site, whereas four Bt hybrids, C8120Bt, P31B13Bt, P33VO8Bt, and NC+5788Bt, had less damage at the irrigated site. In 2000, most Bt hybrids had less ear damage than their non-Bt counterparts at each location. Differences in whorl damage did not translate into yield differences. However, variations in ear damage were partially reflected in yield differences. In 1999, P31B13Bt and P33V08Bt had higher yields than their non-Bt counterparts at both sites, whereas in 2000 all Bt hybrids had higher yields. Also, although whorl damage was not correlated with yield, ear damage was negatively correlated with yield; increasing ear damage by H. zea decreased yield for Bt and non-Bt hybrids alike. Overall, depending on location and year, each centimeter of H. zea ear damage reduced yield by between 2 and 13%.

  10. 75 FR 24373 - Cotton Research and Promotion Program: Designation of Cotton-Producing States

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-05

    ... Service 7 CFR Part 1205 RIN 0581-AC84 Cotton Research and Promotion Program: Designation of Cotton... Marketing Service (AMS) is amending the Cotton Research and Promotion Order (Cotton Order) following a... Bill) that amended the Cotton Research and Promotion Act (Cotton Act). The 2008 Farm Bill provided...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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.

  2. 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.

  3. 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.

  4. Cotton insect pest management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton production is challenged worldwide by a diversity of arthropod pests that require management to prevent or reduce crop damage. Advances in arthropod control technologies and improved insect and crop management systems have dramatically reduced levels of arthropod damage and the need for inse...

  5. 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)

  6. 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 ...

  7. Fabricating Cotton Analytical Devices.

    PubMed

    Lin, Shang-Chi; Hsu, Min-Yen; Kuan, Chen-Meng; Tseng, Fan-Gang; Cheng, Chao-Min

    2016-08-30

    A robust, low-cost analytical device should be user-friendly, rapid, and affordable. Such devices should also be able to operate with scarce samples and provide information for follow-up treatment. Here, we demonstrate the development of a cotton-based urinalysis (i.e., nitrite, total protein, and urobilinogen assays) analytical device that employs a lateral flow-based format, and is inexpensive, easily fabricated, rapid, and can be used to conduct multiple tests without cross-contamination worries. Cotton is composed of cellulose fibers with natural absorptive properties that can be leveraged for flow-based analysis. The simple but elegant fabrication process of our cotton-based analytical device is described in this study. The arrangement of the cotton structure and test pad takes advantage of the hydrophobicity and absorptive strength of each material. Because of these physical characteristics, colorimetric results can persistently adhere to the test pad. This device enables physicians to receive clinical information in a timely manner and shows great potential as a tool for early intervention.

  8. 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...

  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 evaluated ...

  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 conducted ...

  11. 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

  12. 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.

  13. Insect Resistance Management in Bt Maize: Wild Host Plants of Stem Borers Do Not Serve as Refuges in Africa.

    PubMed

    Van den Berg, J

    2017-02-01

    Resistance evolution by target pests threatens the sustainability of Bt maize in Africa where insect resistance management (IRM) strategies are faced by unique challenges. The assumptions, on which current IRM strategies for stem borers are based, are not all valid for African maize stem borer species. The high dose-refuge strategy which is used to delay resistance evolution relies heavily on the presence of appropriate refuges (non-Bt plants) where pests are not under selection pressure and where sufficient numbers of Bt-susceptible individuals are produced to mate with possible survivors on the Bt maize crop. Misidentification of stem borer species and inaccurate reporting on wild host plant diversity over the past six decades created the perception that grasses will contribute to IRM strategies for these pests in Africa. Desired characteristics of refuge plants are that they should be good pest hosts, implying that larval survival is high and that it produces sufficient numbers of high-quality moths. Refuge plants should also have large cover abundance in areas where Bt maize is planted. While wild host plants may suffice in IRM strategies for polyphagous pests, this is not the case with stenophagous pests. This review discusses data of ecological studies and stem borer surveys conducted over the past decade and shows that wild host plants are unsuitable for development and survival of sufficient numbers of stem borer individuals. These grasses rather act as dead-end-trap plants and do not comply with refuge requirements of producing 500 susceptible individuals for every one resistant individual that survives on Bt maize.

  14. Monitoring of resistance development to Bt cotton in field populations of Helicoverpa armigera (Lepidoptera: noctuidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Evolution of resistance threatens the continuing success of transgenic crops expressing insecticidal proteins. One of the key factors for a successful resistance management is the timely implementation of monitoring program to detect early changes of resistance frequency in field populations and imp...

  15. 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...

  16. 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.

  17. 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...

  18. 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...

  19. 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 ...

  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 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…

  2. Removal of methylene blue from aqueous solution using cotton stalk, cotton waste and cotton dust.

    PubMed

    Ertaş, Murat; Acemioğlu, Bilal; Alma, M Hakkı; Usta, Mustafa

    2010-11-15

    In this study, cotton stalk (CS), cotton waste (CW) and cotton dust (CD) was used as sorbents to remove methylene blue (MB) from aqueous solution by batch sorption technique. Effects of initial dye concentration, solution pH, solution temperature and sorbent dose on sorption were studied. It was seen that the removal of methylene blue increased with increasing initial dye concentration (from 25 to 100 mg/l), solution pH (from 5 to 10), solution temperature (from 20 to 50°C) and sorbent dose (from 0.25 to 1.50 g/50 ml). The maximum dye removal was reached at 90 min. Sorption isotherms were analyzed by Langmuir and Freundlich models at different temperatures of 20, 30, 40 and 50°C, and the results were discussed in detail. Moreover, the thermodynamics of sorption were also studied. It was found that the values of standard free energy (ΔG°) were positive for cotton stalk and negative for cotton waste and cotton dust. The values of standard enthalpy (ΔH°) and entropy (ΔS°) were found to be positive, and the obtained results were interpreted in detail. The results of this study showed that cotton stalk, cotton waste and cotton dust could be employed as effective and low-cost materials for the removal of dyes from aqueous solution.

  3. Ingestion of Bt rice pollen does not reduce the survival or hypopharyngeal gland development of Apis mellifera adults.

    PubMed

    Wang, Yuanyuan; Dai, Pingli; Chen, Xiuping; Romeis, Jörg; Shi, Jianrong; Peng, Yufa; Li, Yunhe

    2016-10-07

    Because of its ecological and economic importance, the honey bee Apis mellifera is commonly used to assess the environmental risk of insect-resistant, genetically modified plants. In the current laboratory study, feeding-exposure experiments were used to determine whether pollen from transgenic rice harms A. mellifera worker bee. In one experiment, the survival and mean acinus diameter of hypopharyngeal glands of adult bees were similar when bees were fed on pollen from Bt rice lines or from a non-Bt rice line, but bee survival was significantly reduced when they received pollen that was mixed with potassium arsenate as a positive control. In a second experiment, bee survival and hypopharyngeal gland development were not reduced when adult bees were fed on non-Bt pollen and a sucrose solution supplemented with Cry2A at 400 µg/g, Cry1C at 50 µg/g, or bovine serum albumin (BSA) at 400 µg/g diet, but bee survival and hypopharyngeal gland development were reduced when the diet was supplemented with soybean trypsin inhibitor (SBTI) as a positive control. In both experiments, the uptake of Cry proteins by adult bees was confirmed. Overall, the results indicate that the planting of Bt rice lines expressing Cry2A or Cry1C protein poses a negligible risk to A. mellifera worker bees. This article is protected by copyright. All rights reserved.

  4. 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...

  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, 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...

  7. 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...

  8. 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...

  9. Evaluation of the BT-1 serum assay for breast cancer.

    PubMed

    Whitehurst, M M; Aldenderfer, P H; Sooy, M M; Strelkauskas, A J

    1999-01-01

    The BT-1 assay which identifies a novel breast tumor associated serum analyte was performed for 143 patients previously diagnosed with breast cancer. Mucin tumor markers CA15-3/CA27-29 values were available for 50 patients and there was very minor overlap between patients positive by both tests. Patients' follow-up clinical status at sample draw was compared to BT-1 assay results. 27% of patients originally diagnosed as Stage II and 20% patients originally diagnosed as Stage III who were evaluated 'no disease' had positive BT-1 values. 8% patients diagnosed as Stage II had negative BT-1 results in samples drawn within 90 days of chemotherapy initiation, whereas 23% of patients diagnosed as Stage III cancer were BT-1 test positive within 90 days of chemotherapy initiation. 50% of patients tested before initial breast cancer surgery had positive BT-1 values, suggesting that the BT-1 assay may be useful in identification women with more advanced disease at diagnosis.

  10. 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...

  11. 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...

  12. 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 ...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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

  5. Harmonia axyridis (Coleoptera: Coccinellidae) exhibits no preference between Bt and non-Bt maize fed Spodoptera frugiperda (Lepidoptera: Noctuidae).

    PubMed

    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.

  6. Developing Analytic Rating Guides for "TOEFL iBT"® Integrated Speaking Tasks. "TOEFL iBT"® Research Report, TOEFL iBT-20. ETS Research Report. RR-13-13

    ERIC Educational Resources Information Center

    Jamieson, Joan; Poonpon, Kornwipa

    2013-01-01

    Research and development of a new type of scoring rubric for the integrated speaking tasks of "TOEFL iBT"® are described. These "analytic rating guides" could be helpful if tasks modeled after those in TOEFL iBT were used for formative assessment, a purpose which is different from TOEFL iBT's primary use for admission…

  7. [Ecology and ecologies].

    PubMed

    Valera, Luca

    2011-01-01

    Ecology (from the Greek words οιχοσ, "house" and λογια "study of") is the science of the "house", since it studies the environments where we live. There are three main ways of thinking about Ecology: Ecology as the study of interactions (between humans and the environment, between humans and living beings, between all living beings, etc.), Ecology as the statistical study of interactions, Ecology as a faith, or rather as a science that requires a metaphysical view. The history of Ecology shows us how this view was released by the label of "folk sense" to gain the epistemological status of science, a science that strives to be interdisciplinary. So, the aim of Ecology is to study, through a scientific methodology, the whole natural world, answering to very different questions, that arise from several fields (Economics, Biology, Sociology, Philosophy, etc.). The plurality of issues that Ecology has to face led, during the Twentieth-century, to branch off in several different "ecologies". As a result, each one of these new approaches chose as its own field a more limited and specific portion of reality.

  8. 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

  9. Vip3A resistance alleles exist at high levels in Australian targets before release of cotton expressing this toxin.

    PubMed

    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.

  10. 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.

  11. 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).

  12. Functional analysis of a reproductive organ predominant expressing promoter in cotton plants.

    PubMed

    Ren, Maozhi; Chen, Quanjia; Li, Li; Zhang, Rui; Guo, Sandui

    2005-10-01

    Transgenic Bt insect-resistant cotton plants have high insect resistance in the early stage of development, but relatively low resistance in the late stage. Substituting a reproductive organ-specific promoter for the CaMV35S promoter presently being used could be an ideal solution. For the first time, the promoter sequence of ADP-ribosylation factor 1 (arf1) gene was isolated from Gossypium hirsutumY18 by means of inverse PCR. The sequencing result discovered the unique structure of the arf1 promoter, including four promoter-specific elements, the initiator, TATA box, CAAT box and GC box, and also an intron in 5'-untranslation region. Four plant expression vectors were constructed for functional analysis of the promoter. Based on the pBl121 plant expression vector, four truncated arf1 promoters took the place of the CaMV35S promoter. These vectors were different only in their promoter regions. They were introduced into cotton plants via pollen tube pathway. Histochemical GUS staining and fluorescence quantitative analyses were performed to examine the expression patterns of the GUS gene driven by the 4 arf1 truncated promoters in transgenic cotton plants respectively. The results showed that the arf1 promoter was a typical reproductive organ-specific promoter. Hopefully, the arf1 promoter can be a regulatory element for designing cotton reproductive organs with desired characteristics.

  13. Autonomous cotton module forming system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton producers often have difficulty finding adequate labor during harvest. Module builder operators are often inexperienced and may build poorly shaped modules. Equipment manufacturers have recently introduced harvesters with on-board module building capabilities to reduce labor requirements; h...

  14. Antiquity of American Polyploid Cotton.

    PubMed

    Smith, C E; Macneish, R S

    1964-02-14

    Fragments of a boll of Gossypium hirsutum L. from archeological excavations near Tehuacán, Mexico, prove that this species existed in 5800 B. C. No doubt remains that American tetraploid cotton species originated through natural hiybridization.

  15. In situ synthesis of silver nanoparticles on the cotton fabrics modified by plasma induced vapor phase graft polymerization of acrylic acid for durable multifunction

    NASA Astrophysics Data System (ADS)

    Wang, C. X.; Ren, Y.; Lv, J. C.; Zhou, Q. Q.; Ma, Z. P.; Qi, Z. M.; Chen, J. Y.; Liu, G. L.; Gao, D. W.; Lu, Z. Q.; Zhang, W.; Jin, L. M.

    2017-02-01

    A practical and ecological method for preparing the multifunctional cotton fabrics with excellent laundering durability was explored. Cotton fabrics were modified by plasma induced vapor phase graft polymerization (PIVPGP) of acrylic acid (AA) and subsequently silver nanoparticles (AgNPs) were in situ synthesized on the treated cotton fabrics. The AgNP loaded cotton fabrics were characterized by scanning electron microscope (SEM), energy dispersive X-ray (EDX), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), antibacterial activity, self-cleaning activity, thermal stability and laundering durability, respectively. SEM observation and EDX, XPS and XRD analysis demonstrated the much more AgNPs deposition on the cotton fabrics modified by PIVPGP of AA. The AgNP loaded cotton fabrics also exhibited better antibacterial activity, self-cleaning activity, thermal stability and laundering durability. It was concluded that the surface modification of the cotton fabrics by PIVPGP of AA could increase the loading efficiency and binding fastness of AgNPs on the treated cotton fabrics, which could fabricate the cotton fabrics with durable multifunction. In addition, the mechanism of in situ synthesis of AgNPs on the cotton fabrics modified by PIVPGP of AA was proposed.

  16. 7 CFR 28.451 - Below Color Grade Cotton.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Below Color Grade Cotton. 28.451 Section 28.451... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Below Color Grade Cotton § 28.451 Below Color Grade Cotton. Below color grade cotton is American Upland cotton which is lower in color grade than...

  17. 7 CFR 28.451 - Below Color Grade Cotton.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Below Color Grade Cotton. 28.451 Section 28.451... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Below Color Grade Cotton § 28.451 Below Color Grade Cotton. Below color grade cotton is American Upland cotton which is lower in color grade than...

  18. 7 CFR 28.451 - Below Color Grade Cotton.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Below Color Grade Cotton. 28.451 Section 28.451... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Below Color Grade Cotton § 28.451 Below Color Grade Cotton. Below color grade cotton is American Upland cotton which is lower in color grade than...

  19. 7 CFR 28.451 - Below Color Grade Cotton.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Below Color Grade Cotton. 28.451 Section 28.451... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Below Color Grade Cotton § 28.451 Below Color Grade Cotton. Below color grade cotton is American Upland cotton which is lower in color grade than...

  20. 7 CFR 28.451 - Below Color Grade Cotton.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Below Color Grade Cotton. 28.451 Section 28.451... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Below Color Grade Cotton § 28.451 Below Color Grade Cotton. Below color grade cotton is American Upland cotton which is lower in color grade than...

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  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 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  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, 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...

  18. 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...

  19. Nanowire-functionalized cotton textiles.

    PubMed

    Zhukovskyi, Maksym; Sanchez-Botero, Lina; McDonald, Matthew P; Hinestroza, Juan; Kuno, Masaru

    2014-02-26

    We show the general functionalization of cotton fabrics using solution-synthesized CdSe and CdTe nanowires (NWs). Conformal coatings onto individual cotton fibers have been achieved through various physical and chemical approaches. Some involve the electrostatic attraction of NWs to cotton charged positively with a Van de Graaff generator or via 2,3-epoxypropyltrimethylammonium chloride treatments. Resulting NW-functionalized textiles consist of dense, conformal coatings and have been characterized for their UV-visible absorption as well as Raman activity. We demonstrate potential uses of these functionalized textiles through two proof-of-concept applications. The first entails barcoding cotton using the unique Raman signature of the NWs. We also demonstrate the surface-enhancement of their Raman signatures using codeposited Au. A second demonstration takes advantage of the photoconductive nature of semiconductor NWs to create cotton-based photodetectors. Apart from these illustrations, NW-functionalized cotton textiles may possess other uses in the realm of medical, anticounterfeiting, and photocatalytic applications.

  20. [Arachnofauna (araneae: Araneae) in transgenic and conventional cotton crops (Gossypium hirsutum) in the North of Santa Fe, Argentina].

    PubMed

    Almada, Melina Soledad; Sosa, María Ana; González, Alda

    2012-06-01

    Spiders have considerable potential importance for their role as predators to some pests in agricultural systems. The composition of spiders in transgenic and conventional cotton at the Research Station of INTA Reconquista (Santa Fe) was studied during the 2005-2006 season. The experiment was a complete randomized block design with three replications and three treatments: transgenic Bt cotton (ALBt), conventional cotton without chemical control (ALCSC), and conventional cotton with chemical control (ALCCC). Weekly, spiders were collected using nets, vertical cloth and pitfall-traps. A total of 1255 specimens (16 families, and 32 species) were collected. Seven families were found in all the treatments, mainly Thomisidae (n=1 51, 84.04%) and Araneidae (n=83, 6.64%). The Hunting spiders guild ambushers (n=1053, 83.91%), "Orb weavers" (n=85, 6.77%) and "Stalkers" (n=53, 4.22%) were more abundant. There were no significant differences in the indexes diversity between treatments. Spiders were presented during the whole crop season, with peaks about flowering and boll maturity, with the highest abundance in ALBt. This work is part of the first set of data registered in Argentina about spider's community in cotton crops.

  1. Defining terms for proactive management of resistance to Bt crops and pesticides.

    PubMed

    Tabashnik, Bruce E; Mota-Sanchez, David; Whalon, Mark E; Hollingworth, Robert M; Carrière, Yves

    2014-04-01

    Evolution of pest resistance to pesticides is an urgent global problem with resistance recorded in at least 954 species of pests, including 546 arthropods, 218 weeds, and 190 plant pathogens. To facilitate understanding and management of resistance, we provide definitions of 50 key terms related to resistance. We confirm the broad, long-standing definition of resistance, which is a genetically based decrease in susceptibility to a pesticide, and the definition of "field-evolved resistance," which is a genetically based decrease in susceptibility to a pesticide in a population caused by exposure to the pesticide in the field. The impact of field-evolved resistance on pest control can vary from none to severe. We define "practical resistance" as field-evolved resistance that reduces pesticide efficacy and has practical consequences for pest control. Recognizing that resistance is not "all or none" and that intermediate levels of resistance can have a continuum of effects on pest control, we describe five categories of field-evolved resistance and use them to classify 13 cases of field-evolved resistance to five Bacillus thuringiensis (Bt) toxins in transgenic corn and cotton based on monitoring data from five continents for nine major pest species. We urge researchers to publish and analyze their resistance monitoring data in conjunction with data on management practices to accelerate progress in determining which actions will be most useful in response to specific data on the magnitude, distribution, and impact of resistance.

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

    PubMed

    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.

  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. 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

  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. 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...

  7. 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.

  8. 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

  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. [Effects of drought and re-watering on endogenous hormone contents of cotton roots and leaves under drip irrigation with mulch].

    PubMed

    Luo, Hong-hai; Han, Huan-yong; Zhang, Ya-li; Zhang, Wang-feng

    2013-04-01

    Under the climatic and ecological conditions of Xingjiang, Northwest China, different degrees of drought stress were installed during the growth stages of cotton, and the drip irrigation with mulch was adopted, aimed to study the effects of drought stress and re-watering on the endogenous hormones (abscisic acid, ABA; and zeatins, ZRs) contents of cotton roots and leaves and the stomatal conductance (gs) of cotton leaves. With the increase of drought stress at different growth stages, the ABA contents of cotton roots and leaves increased, while the ZRs contents of cotton roots and leaves and the gsand photosynthetic rate (Pn) of cotton leaves decreased, with greater decrements in the treatment of soil moisture content being 40% -45% of field capacity at early flowering-full flowering stage. After re-watering, the ABA contents of cotton roots and leaves d:d not have a decrease with the improvement of soil moisture regime, while the ZRs contents of cotton roots recovered rapidly or exceeded the control after 1-3 days of re-watering. There was a positive correlation between the ZRs contents of cotton roots and the gs of cotton leaves. In the treatment of soil moisture content being 50% -55% of field capacity at full budding-early flowering stage, the ZRs contents and gs of cotton leaves recovered more quickly and with greater increments. It was suggested that the higher ZRs contents of cotton roots after re-watering could be the main cause for the higher stomatal conductance and photosynthetic rate of cotton leaves.

  11. 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.

  12. 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

  13. 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…

  14. 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 ...

  15. Biobased polymeric materials prepared from cotton byproducts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton burr and cottonseed hull are relatively inexpensive natural renewable materials from cotton and cottonseed processing. Recently several new polymer applications have been reported involving these cotton byproducts. These new developments are briefly reviewed in this article. In the first a...

  16. 77 FR 19925 - Upland Cotton Base Quality

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-03

    ... Corporation 7 CFR Part 1427 RIN 0560-AI16 Upland Cotton Base Quality AGENCY: Commodity Credit Corporation and... Commodity Credit Corporation (CCC) upland cotton marketing assistance loan (MAL) regulations to revise... further specification. CCC uses base quality to calculate upland cotton loan rates, Adjusted World...

  17. 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...

  18. 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 ...

  19. 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...

  20. 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...

  1. 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.

  2. Acute, Sublethal, and Combination Effects of Azadirachtin and Bacillus thuringiensis on the Cotton Bollworm, Helicoverpa armigera

    PubMed Central

    Abedi, Zahra; Saber, Moosa; Vojoudi, Samad; Mahdavi, Vahid; Parsaeyan, Ehsan

    2014-01-01

    The cotton bollworm, Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) is a polyphagous and cosmopolitan insect pest that causes damage to various plants. In this study, the lethal and sublethal effects of azadirachtin and Bacillus thuringiensis Berliner sub sp. kurstaki (Bacillales: Bacillaceae) were evaluated on third instar H. armigera under laboratory conditions. The LC50 values of azadirachtin and Bt were 12.95 and 96.8 µg a.i./mL, respectively. A total mortality of 56.7% was caused on third instar larvae when LC20 values of the insecticides were applied in combination with each other. The LT50 values of azadirachtin and Bt were 4.8 and 3.6 days, respectively. The results of the sublethal study showed that the application of LC30 value of azadirachtin and Bt reduced the larval and pupal weight and increased larval and pupal duration of H. armigera. The longevity and fecundity of female adults were affected significantly by the insecticides. Female fecundity was reduced by the treatments, respectively. The lowest adult emergence ratio and pupation ratio were observed in the azadirachtin treatment. The results indicated that both insecticides have high potential for controlling of the pest. PMID:25373177

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. Multifunctional finishing of cotton using chitosan extracted from bio-waste.

    PubMed

    Teli, M D; Sheikh, Javed; Bhavsar, Parag

    2013-03-01

    In the current work, chitosan extracted from waste shrimp shells was used in finishing formulation for cotton fabric, along with DMDHEU and other chemicals, imparting multiple performance characteristics such as wrinkle free, antibacterial and flame retardant properties. The finished fabrics were evaluated for textile properties like tensile strength, bending length, yellowness index and functional properties like crease recovery angle, antibacterial activity and flame retardancy and also for the ecological properties like formaldehyde release. The finished fabric showed excellent crease recovery, antibacterial property and flame retardancy which were retained to a moderate extent even after 20 washes. Besides formaldehyde scavenging action, chitosan clearly showed its positive role in imparting multifunctional properties to cotton.

  8. 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)

  9. Graphene oxide nanostructures modified multifunctional cotton fabrics

    NASA Astrophysics Data System (ADS)

    Krishnamoorthy, Karthikeyan; Navaneethaiyer, Umasuthan; Mohan, Rajneesh; Lee, Jehee; Kim, Sang-Jae

    2012-06-01

    Surface modification of cotton fabrics using graphene oxide (GO) nanostructures was reported. Scanning electron microscopic (SEM) investigations revealed that the GO nanostructure was coated onto the cotton fabric. The molecular level interaction between the graphene oxide and the cotton fabric is studied in detail using the Fourier transform infra-red (FTIR) spectra. Thermogravimetric analysis (TGA) showed that GO loaded cotton fabrics have enhanced thermal stability compared to the bare cotton fabrics. The photocatalytic activity of the GO-coated cotton fabrics was investigated by measuring the photoreduction of resazurin (RZ) into resorufin (RF) under UV light irradiation. The antibacterial activity was evaluated against both Gram-negative and Gram-positive bacteria and the results indicated that the GO-coated cotton fabrics are more toxic towards the Gram-positive ones. Our results provide a way to develop graphene oxide-based devices for the biomedical applications for improving health care.

  10. Cutinase promotes dry esterification of cotton cellulose.

    PubMed

    Xiaoman, Zhao; Teresa, Matama; Artur, Ribeiro; Carla, Silva; Jing, Wu; Jiajia, Fu; Artur, Cavaco-Paulo

    2016-01-01

    Cutinase from Thermobifida fusca was used to esterify the hydroxyl groups of cellulose with the fatty acids from triolein. Cutinase and triolein were pre-adsorbed on cotton and the reaction proceeded in a dry state during 48 h at 35°C. The cutinase-catalyzed esterification of the surface of cotton fabric resulted in the linkage of the oleate groups to the glycoside units of cotton cellulose. The superficial modification was confirmed by performing ATR-FTIR on treated cotton samples and by MALDI-TOF analysis of the liquors from the treatment of the esterified cotton with a crude cellulase mixture. Modified cotton fabric also showed a significant increase of hydrophobicity. This work proposes a novel bio-based approach to obtain hydrophobic cotton.

  11. Field-based assessment of resistance to Bt Corn by Western Corn Rootworm (Coleoptera: Chrysomelidae)

    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. Cadherin Gene Expression and Effects of Bt Resistance on Sperm Transfer in Pink Bollworm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cadherin proteins bind Bacillus thuringiensis (Bt) toxins in lepidopteran midguts but their inherent function remains unclear. In pink bollworm, Pectinophora gossypiella, three recessive mutations in a cadherin gene (BtR) are tightly linked with resistance to Bt toxin Cry1Ac. Here we examined patt...

  13. Endophytic fungi alter sucking bug responses to cotton reproductive structures.

    PubMed

    Sword, Gregory A; Tessnow, Ashley; Ek-Ramos, Maria Julissa

    2017-03-22

    All plants including cotton host a wide range of microorganisms as endophytes. There is a growing appreciation of the prevalence, ecological significance and management potential of facultative fungal endophytes in protecting plants from pests, pathogens and environmental stressors. Hemipteran sucking bugs have emerged as major pests across the US cotton belt, reducing yields directly by feeding on developing reproductive structures and indirectly by vectoring plant pathogens. We used no-choice and simultaneous choice assays to examine the host selection behavior of western tarnished plant bugs (Lygus hesperus) and southern green stink bugs (Nezara viridula) in response to developing flower buds and fruits from cotton plants colonized by one of two candidate beneficial fungal endophytes, Phialemonium inflatum or Beauveria bassiana. Both insect species exhibited strong negative responses to flower buds (L. hesperus) and fruits (N. viridula) from plants that had been colonized by candidate endophytic fungi relative to control plants under both no-choice and choice conditions. Behavioral responses of both species indicated that the insects were deterred prior to contact with plant tissues from endophyte-colonized plants, suggesting a putative role for volatile compounds in mediating the negative response. Our results highlight the role of fungal endophytes as plant mutualists that can have positive effects on plant resistance to pests. This article is protected by copyright. All rights reserved.

  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. 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 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...

  17. 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...

  18. 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...

  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 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  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 28.105 - 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 28.40 - Terms defined; cotton classification.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 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 28.106 - 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  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 27.73 - 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. Cotton moisture – its importance, measurements and impacts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton moisture impacts cotton from field to fabric. The proper control, and measurement to allow for control, of cotton moisture is essential to maintaining and preserving fiber quality. Cotton color, length and strength; as well as other properties, are all impacted by cotton moisture content. ...

  2. Progress in the Cotton Industry

    ERIC Educational Resources Information Center

    Training Officer, 1974

    1974-01-01

    The training needs of the cotton industry have fostered a movement within that industry to develop more trainers and improve management training. Since 1966, through seminars, training programs, grants programs and proper recruitment, 6,000 more qualified training instructors have been added to the industry. (DS)

  3. Towards Sequencing Cotton (Gossypium) Genomes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite rapidly decreasing costs and innovative technologies, sequencing of angiosperm genomes is not yet undertaken lightly. Generating larger amounts of sequence data more quickly does not address the difficulties of sequencing and assembling complex genomes de novo. The cotton genomes represent a...

  4. 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 ...

  5. 6-Benzyladenine enhancement of cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The influence of applied plant growth regulators (PGR) on growth, development and yield in cotton (Gossypium hirsutum L. and Gossypium barbadense L.) has been studied for over half a century. Studies of PGR containing cytokinin alone or in combination with gibbererillins applied at the pinhead squa...

  6. 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...

  7. 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 ...

  8. 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...

  9. Microwave Imaging of Cotton Bales

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Modern moisture restoration systems are increasingly capable of adding water to cotton bales. However, research has identified large variations in internal moisture within bales that are not readily monitored by current systems. While microwave moisture sensing systems can measure average bale moist...

  10. 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...

  11. 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

  12. 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.

  13. 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…

  14. Investigating the Value of Section Scores for the "TOEFL iBT"® Test. "TOEFL iBT"® Research Report. TOEFL iBT-21. ETS Research Report RR-13-35

    ERIC Educational Resources Information Center

    Sawaki, Yasuyo; Sinharay, Sandip

    2013-01-01

    This study investigates the value of reporting the reading, listening, speaking, and writing section scores for the "TOEFL iBT"® test, focusing on 4 related aspects of the psychometric quality of the TOEFL iBT section scores: reliability of the section scores, dimensionality of the test, presence of distinct score profiles, and the…

  15. Discourse Characteristics of Writing and Speaking Task Types on the "TOEFL iBT"® Test: A Lexico-Grammatical Analysis. "TOEFL iBT"® Research Report. TOEFL iBT-19. Research Report. RR-13-04

    ERIC Educational Resources Information Center

    Biber, Douglas; Gray, Bethany

    2013-01-01

    One of the major innovations of the "TOEFL iBT"® test is the incorporation of integrated tasks complementing the independent tasks to which examinees respond. In addition, examinees must produce discourse in both modes (speech and writing). The validity argument for the TOEFL iBT includes the claim that examinees vary their discourse in…

  16. Detection methods for biotech cotton MON 15985 and MON 88913 by PCR.

    PubMed

    Lee, Seong-Hun; Kim, Jin-Kug; Yi, Bu-Young

    2007-05-02

    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.

  17. 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

  18. Optimizing pyramided transgenic Bt crops for sustainable pest management.

    PubMed

    Carrière, Yves; Crickmore, Neil; Tabashnik, Bruce E

    2015-02-01

    Transgenic crop pyramids producing two or more Bacillus thuringiensis (Bt) toxins that kill the same insect pest have been widely used to delay evolution of pest resistance. To assess the potential of pyramids to achieve this goal, we analyze data from 38 studies that report effects of ten Bt toxins used in transgenic crops against 15 insect pests. We find that compared with optimal low levels of insect survival, survival on currently used pyramids is often higher for both susceptible insects and insects resistant to one of the toxins in the pyramid. Furthermore, we find that cross-resistance and antagonism between toxins used in pyramids are common, and that these problems are associated with the similarity of the amino acid sequences of domains II and III of the toxins, respectively. This analysis should assist in future pyramid design and the development of sustainable resistance management strategies.

  19. 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.

  20. 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...