Bibliografias temáticas / Pink bollworm resistance to Bt Cotton

Literatura científica selecionada sobre o tema "Pink bollworm resistance to Bt Cotton"

Autor: Grafiati

Publicado: 26 de julho de 2024

Última modificação: 27 de julho de 2024

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Artigos de revistas sobre o assunto "Pink bollworm resistance to Bt Cotton"

Sun, Zhan-Bin, Ya-Feng Hu, Han-Jian Song, Sheng-Bo Cong e Ling Wang. "Cry1Ac Mixed with Gentamicin Influences the Intestinal Microbial Diversity and Community Composition of Pink Bollworms". Life 14, n.º 1 (28 de dezembro de 2023): 58. http://dx.doi.org/10.3390/life14010058.

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Pink bollworms severely affect the production of cotton. The method currently used for pink bollworm control is the planting of Bt (Bacillus thuringiensis) protein-expressing transgenic cotton. However, pink bollworms can develop strong resistance to Bt proteins in transgenic cotton because of the large planting area and long planting time of this crop, which severely affects the control of pink bollworms. Intestinal microorganisms play very important roles in insect growth, development and Bt resistance. However, the effect of intestinal microorganisms on pink bollworm Bt resistance is still unclear. The current study aimed to analyze the effect of intestinal microorganisms on the Bt resistance of pink bollworms. Intestinal microorganisms associated with Bt resistance were initially screened through Illumina MiSeq sequencing and analysis. The results showed that feeding with a mixture of gentamicin, Cry1Ac and an artificial diet could significantly increase the mortality of pink bollworm larvae compared with feeding with of a mixture of Cry1Ac and an artificial diet or an artificial diet alone. The microbial diversity, community structure and composition of the pink bollworm larval intestine were significantly influenced by feeding with a mixture of gentamicin, Cry1Ac and an artificial diet. Several intestinal bacteria with significantly altered abundances after treatment with gentamicin were preliminarily screened as potential resources for addressing Bt toxicity. This study provides useful strategies for addressing the Bt resistance of pink bollworms.

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Tabashnik, Bruce E., e Yves Carrière. "Global Patterns of Resistance to Bt Crops Highlighting Pink Bollworm in the United States, China, and India". Journal of Economic Entomology 112, n.º 6 (29 de junho de 2019): 2513–23. http://dx.doi.org/10.1093/jee/toz173.

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Abstract Crops genetically engineered to produce insecticidal proteins from Bacillus thuringiensis (Bt) have advanced pest control, but their benefits have been reduced by evolution of resistance in pests. The global monitoring data reviewed here reveal 19 cases of practical resistance to Bt crops, which is field-evolved resistance that reduces Bt crop efficacy and has practical consequences for pest control. Each case represents the responses of one pest species in one country to one Bt toxin. The results with pink bollworm (Pectinophora gossypiella) and Bt cotton differ strikingly among the world’s three leading cotton-producing nations. In the southwestern United States, farmers delayed resistance by planting non-Bt cotton refuges from 1996 to 2005, then cooperated in a program that used Bt cotton, mass releases of sterile moths, and other tactics to eradicate this pest from the region. In China, farmers reversed low levels of pink bollworm resistance to Bt cotton by planting second-generation hybrid seeds from crosses between Bt and non-Bt cotton. This approach yields a refuge of 25% non-Bt cotton plants randomly interspersed within fields of Bt cotton. Farmers adopted this tactic voluntarily and unknowingly, not to manage resistance, but apparently because of its perceived short-term agronomic and economic benefits. In India, where non-Bt cotton refuges have been scarce and pink bollworm resistance to pyramided Bt cotton producing Cry1Ac and Cry2Ab toxins is widespread, integrated pest management emphasizing shortening of the cotton season, destruction of crop residues, and other tactics is now essential.

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Fabrick, Jeffrey A., Xianchun Li, Yves Carrière e Bruce E. Tabashnik. "Molecular Genetic Basis of Lab- and Field-Selected Bt Resistance in Pink Bollworm". Insects 14, n.º 2 (17 de fevereiro de 2023): 201. http://dx.doi.org/10.3390/insects14020201.

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Transgenic crops producing insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) control some important insect pests. However, evolution of resistance by pests reduces the efficacy of Bt crops. Here we review resistance to Bt cotton in the pink bollworm, Pectinophora gossypiella, one of the world’s most damaging pests of cotton. Field outcomes with Bt cotton and pink bollworm during the past quarter century differ markedly among the world’s top three cotton-producing countries: practical resistance in India, sustained susceptibility in China, and eradication of this invasive lepidopteran pest from the United States achieved with Bt cotton and other tactics. We compared the molecular genetic basis of pink bollworm resistance between lab-selected strains from the U.S. and China and field-selected populations from India for two Bt proteins (Cry1Ac and Cry2Ab) produced in widely adopted Bt cotton. Both lab- and field-selected resistance are associated with mutations affecting the cadherin protein PgCad1 for Cry1Ac and the ATP-binding cassette transporter protein PgABCA2 for Cry2Ab. The results imply lab selection is useful for identifying genes important in field-evolved resistance to Bt crops, but not necessarily the specific mutations in those genes. The results also suggest that differences in management practices, rather than genetic constraints, caused the strikingly different outcomes among countries.

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Prasada Rao, G. M. V. "Indian scenario on the occurrence of a dreaded insect pest Pink bollworm, Pectinophora gossypiella on Bt cotton-A review". Journal of Environmental Biology 43, n.º 1 (7 de janeiro de 2022): 11–19. http://dx.doi.org/10.22438/jeb/43/1/mrn-1850.

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The pink bollworm, Pectinophora gossypiella, has become a significant production constraint on Bt cotton in India. This problem is unique to India because the pest has developed multi-fold resistance to Cry toxins in many Indian populations but not in other countries. Most Indian populations have developed multifold resistance to Cry 1 Ac and Cry 1Ac + Cry 2 Ab toxins. Year-round cultivation of long-duration Bt cotton hybrids on a large scale has a pronounced impact on the incidence. Also discussed other factors responsible for the occurrence of pink bollworm on Bt cotton in India. Insecticide Resistance Management (IRM) strategies implemented by different cotton-growing countries globally; the USA, India, and China had a significant impact on the interaction of pink bollworm on Bt cotton. Huge selection pressure resulted in resistance to Cry toxins. Time-tested IPM, if implemented on a community basis focusing on pheromones technology and closed season, will help sustain the cotton cultivation in India in the future. Thus, this review aims to congregate exhaustive information on the history, biology, resistance to Bt cotton, and Integrated Management (IPM) options for the Indian scenario, which would help researchers in their future endeavors.

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Quan, Yudong, e Kongming Wu. "Managing Practical Resistance of Lepidopteran Pests to Bt Cotton in China". Insects 14, n.º 2 (10 de fevereiro de 2023): 179. http://dx.doi.org/10.3390/insects14020179.

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China is one of the major cotton producers globally with small farmers. Lepidopteran pests have always been the main factor affecting cotton production. To reduce the occurrence of and damage caused by lepidopteran pests, China has employed a pest control method focused on planting Bt (Cry1Ac) cotton since 1997. Chinese resistance management tactics for the main target pests, the cotton bollworm and pink bollworm, were also implemented. For polyphagous (multiple hosts) and migratory pests such as the cotton bollworm (Helicoverpa armigera), the “natural refuge” strategy, consisting of non-Bt crops such as corn, soybean, vegetables, peanuts, and other host crops, was adopted in the Yellow River Region (YRR) and Northwest Region (NR). For a single host and weak migration ability pest, such as the pink bollworm (Pectinophora gossypiella), the seed mix refuge strategy yields a random mixture within fields of 25% non-Bt cotton by sowing second-generation (F2) seeds. According to field monitoring results for more than 20 years in China, practical resistance (Bt cotton failure) of target pests was avoided, and there were no cases of Bt (Cry1Ac) failure of pest control in cotton production. This indicated that this Chinese resistance management strategy was very successful. The Chinese government has decided to commercialize Bt corn, which will inevitably reduce the role of natural refuges; therefore, this paper also discusses adjustments and future directions of cotton pest resistance management strategies.

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Verma, D., M. H. Kalubarme, G. P. Saroha, K. S. Mohan, K. C. Ravi e A. N. Singh. "MONITORING CHANGES IN COTTON ACREAGE AND ALTERNATE HOST CROPS OF COTTON BOLLWORM USING REMOTE SENSING AND GIS IN MAJOR COTTON GROWING REGIONS OF INDIA". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-3/W6 (26 de julho de 2019): 525–33. http://dx.doi.org/10.5194/isprs-archives-xlii-3-w6-525-2019.

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Abstract. Cotton cultivation has made rapid strides in India since the introduction of Bt cotton, which provided effective protection against its major pest, Helicoverpa armigera and other bollworms. The presence of alternate host crops for cotton bollworms targeted by Bt cotton play a key role in resistance evolution to the in planta expressed Bt proteins. Several host crops for H. armigera such as pigeonpea, sorghum, tomato, chilli, sunflower and corn are cultivated alongside Bt cotton. Change detection in the extent of cotton and alternate host crops of cotton bollworm was conducted using IRS LISS-III data in Punjab, Haryana, Rajasthan, Gujarat, Maharashtra, Andhra Pradesh and Karnataka states. The changes in the extent of cotton and host crops were monitored using multi-temporal data of 2002, 2004 and 2008. The results indicated that Bt cotton (Hirsutum) has almost completely replaced the traditional Indian cotton (Gossypium arborium). Several alternate host crops of H. armigera were grown along with cotton. Pigeonpea was the major host crop in almost all the locations. Chilies dominated in Andhra Pradesh, sunflower in Karnataka and corn in Gujarat. These host crops serve as ‘natural’ refuge of H. armigera and possibly, for this reason this pest has not evolved resistance to the Bt expressed by Bollgard II even after 16 seasons of intensive cultivation; whereas the pink bollworm, a monophagous cotton bollworm, had developed resistance to Cry1Ac in 2009 and to Cry1Ac and Cry2Ab in 2015.

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Wang, Ling, Dong Xu, Yunxin Huang, Huazhong Zhou, Weiguo Liu, Shengbo Cong, Jintao Wang, Wenjing Li e Peng Wan. "Mutation in the Cadherin Gene Is a Key Factor for Pink Bollworm Resistance to Bt Cotton in China". Toxins 14, n.º 1 (1 de janeiro de 2022): 23. http://dx.doi.org/10.3390/toxins14010023.

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Transgenic crops producing Bacillus thuringiensis (Bt) toxins are widely planted for insect control, but their efficacy may decrease as insects evolve resistance. Understanding the genetic basis of insect resistance is essential for developing an integrated strategy of resistance management. To understand the genetic basis of resistance in pink bollworm (Pectinophora gossypiella) to Bt cotton in the Yangtze River Valley of China, we conducted an F2 screening for alleles associated with resistance to the Bt (Cry1Ac) protein for the first time. A total of 145 valid single-paired lines were screened, among which seven lines were found to carry resistance alleles. All field parents in those seven lines carried recessive resistance alleles at the cadherin locus, including three known alleles, r1, r13 and r15, and two novel alleles, r19 and r20. The overall frequency of resistance alleles in 145 lines was 0.0241 (95% CI: 0.0106–0.0512). These results demonstrated that resistance was rare and that recessive mutation in the cadherin gene was the primary mechanism of pink bollworm resistance to Bt cotton in the Yangtze River Valley of China, which will provide a scientific basis for implementing targeted resistance management statics of pink bollworm in this region.

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Vonzun, Messmer, Boller, Shrivas, Patil e Riar. "Extent of Bollworm and Sucking Pest Damage on Modern and Traditional Cotton Species and Potential for Breeding in Organic Cotton". Sustainability 11, n.º 22 (12 de novembro de 2019): 6353. http://dx.doi.org/10.3390/su11226353.

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Resistance against cotton bollworm is one of the main arguments for the use of genetically modified (GM) Bt cotton around the globe. The use of GM is prohibited in organic systems and thus the remunerative value of organic cotton cultivation depends on effective bollworm control. In this study, we investigated the extent of bollworm and sucking pest damage in 68 different hybrid and varietal lines of Gossypium hirsutum and varietal lines of G. arboreum at two different locations with contrasting soil fertility and water dynamics. The damage potential of bollworms was assessed from open capsules at two time points. Sucking pests were assessed at three time points using a scoring method. G. arboreum varietal lines and G. hirsutum hybrids were on average significantly more tolerant than G. hirsutum varietal lines to bollworm under fertile and irrigated situations. For sucking pests, the G. arboreum varietal lines were clearly more tolerant than G. hirsutum hybrids and varietal lines. Since, recently, pink bollworm (Pectinophora gossypiella) became resistant against Bt cotton and pressure of sucking pests severely increased, screening of genetic resources and systems-based cotton breeding for bollworm and sucking pest tolerance will improve sustainability of organic and conventional cotton production.

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Kong-Ming, Wu. "Environmental impact and risk management strategies of Bt cotton commercialization in China". Chinese Journal of Agricultural Biotechnology 4, n.º 2 (agosto de 2007): 93–97. http://dx.doi.org/10.1017/s1479236207001490.

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AbstractTransgenic cotton expressing the Cry1Ac toxin from Bacillus thuringiensis has been planted widely in China since 1997, and reached 70% of the total cotton area in 2006. The results of monitoring the environmental impact of Bt cotton commercialization indicated that the target pests, cotton bollworm (Helicoverpa armigera) and pink bollworm (Pectinophora gossypiella), were effectively controlled while the mirids (Hemiptera: Miridae) evolved to be key pests in the cotton system. There were no significant changes in resistance gene frequency of field populations of cotton bollworm, but a shift toward increased tolerance was apparent in the area of intensive planting of Bt cotton, indicating that the potential risk of resistance of the target pest has become a major threat for sustainable planting of Bt cotton. Considering the factors associated with the evolution of resistance, risk management strategies are discussed in this paper.

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Krishna, M. Sivarama, Y. Srujana, D. Lakshmi Kalyani, K. Venkataramanamma, K. Arun Kumar e K. Mohan Vishnuvardhan. "Evaluation and comparison of different refugia-in-bag (RIB) patterns against boll worm complex with special reference to pink boll worm in Bt cotton". Ecology, Environment and Conservation 29, suppl (2023): 392–97. http://dx.doi.org/10.53550/eec.2023.v29i06s.059.

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Field study on evaluation and comparison of different refugia-in-bag patterns (RIB) against bollworm complex with special reference to pink bollworm was conducted at RARS, Nandyal during 2021 and 2022. Among different RIB patterns evaluated pooled results of two years indicated no significant difference in green boll and locule damage due to pink bollworm among different refugia patterns. Highest yield of 1002 kg/ha was recorded in 20% structured refugia which is statistically at par with all other refugia patterns except in 100% non Bt which recorded lowest yield of 762 kg/ha. Based on foregoing results it clearly states that refugia is longer effective against pink bollworm population which had already developed resistance therefore further development of resistance can be managed in pink bollworm and can be effectively utilized for other bollworm in slowing down the building up of resistance in Bt cotton.

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Teses / dissertações sobre o assunto "Pink bollworm resistance to Bt Cotton"

Dennehy, Timothy J., Gopalan Unnithan, Sarah A. Brink, Brook D. Wood, Yves Carrière, Bruce Tabashnik, Larry Antilla e Mike Whitlow. "Update on Pink Bollworm Resistance to Bt Cotton in the Southwest". College of Agriculture, University of Arizona (Tucson, AZ), 2004. http://hdl.handle.net/10150/198135.

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Monitoring of Arizona pink bollworm (PBW), Pectinophora gossypiella, susceptibility to the Bt toxin Cry1Ac has been conducted annually since 1997. PBW were collected from cotton fields located throughout the Southwest in 2002, cultured in the laboratory, and tested for susceptibility to Cry1Ac using diet-incorporation bioassays. A total of 13 Arizona collections were successfully reared and bioassayed. Collections from California (6), New Mexico (1), and Texas (1) were also tested. Laboratory selection of pink bollworms collected from Arizona in 1997 and exposed to Cry1Ac in diet produced a strain capable of surviving on Bollgard® cotton. Subsequent studies showed that 10 g Cry1Ac/ml of insect diet was a reliable diagnostic concentration for detection of pink bollworm that were homozygous for resistance to Cry1Ac. On this basis, resistant PBW were detected in 2002 in only 2 out of 13 Arizona strains. The overall frequency of resistant PBW in 2002 for Arizona was 0.17% and ranged from 0.0 to 1.7%. One of six California collections evaluated had a single resistant survivor. No resistant pink bollworms were detected in the single New Mexico and Texas collections evaluated. Resistant PBW were significantly more abundant in Arizona in 2001 and 2002 than they were in 1998, 1999 or 2000. However, the frequency of resistant survivors in bioassays was low for 2001 and 2002, and markedly lower than in 1997. The Arizona Cotton Research and Protection Council evaluated the efficacy of Bt cotton in 2002 using adjacent pairs of Bt and non-Bt fields at 43 locations across Arizona. Pink bollworms were found in an average of 23.3% of these non-Bt boll fields. Bolls from Bt cotton fields yielded an average of 0.144% (range 0 to 1.300%) infested bolls. Of these, all but three of the pink bollworm recovered from Bt cotton plantings came from bolls that tested negative for Cry1Ac. We conclude from these findings that there is no indication that pink bollworm resistance to Cry1Ac was a problem at the locations sampled in 2002. Bt cotton continued to exhibit exceptional field performance in Arizona.

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Dennehy, Timothy J., Gopalan C. Unnithan, Virginia Harpold, Yves Carrière, Bruce Tabashnik, Larry Antilla e Mike Whitlow. "Susceptibility of Southwestern Pink Bollworm to Bt toxins Cry1Ac and Cry2Ab2 in 2005". College of Agriculture, University of Arizona (Tucson, AZ), 2007. http://hdl.handle.net/10150/198218.

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Bt cotton is an extremely important tool for integrated pest management in the Southwest. It has been a major factor in the current historic low levels of conventional insecticide use in cotton of this region. This is due to Bt cotton’s unprecedented efficacy against the pink bollworm, Pectinophora gossypiella, and its selectivity in favor of key natural enemies of arthropod pests. Due to the pivotal importance of Bt cotton and widespread concerns about the development of pest resistance to transgenic crops, a multi-agency resistance management program was established to monitor and pro-actively manage resistance development in the pink bollworm. This report constitutes results from the ninth year of this monitoring program. Larvae were obtained from bolls collected in cotton fields located throughout the Southwest, cultured in the laboratory, and offspring tested using diet-incorporation bioassays that discriminate between susceptible and resistant pink bollworm. A total of 11 Arizona and four California collections were successfully reared and tested for susceptibility to Cry1Ac using a discriminating concentration of 10 μg Cry1Ac/ml of diet. Susceptibility to Cry2Ab2 was estimated similarly for 12 strains from Arizona and four from California using diagnostic concentrations of 1.0 and 10 μg Cry2Ab2/ml of diet. Success of pink bollworm eradication in suppressing pink bollworm populations in New Mexico and Texas precluded successful collection of samples in those states. No survivors of 10 μg Cry1Ac/ml were detected in any bioassays of 2005 strains (n=5358). The grand mean frequency of PBW survival of 10 μg Cry1Ac/ml in 2005 was 0.000%. A susceptible culture, APHIS-S, used each year as an internal control, yielded 99.3% corrected mortality in tests of 10μg/ml Cry1Ac (n=490). All twelve pink bollworm strains collected in 2005 were highly susceptible to Cry2Ab2, based on contrasts with baseline data collected from 2001-2003. There were no survivors of bioassays of either 1.0 μg Cry2Ab2/ml (n=1,000) or 10 μg Cry2Ab2/ml (n=3425). The susceptible APHIS-S culture had 82.5% corrected mortality in tests of 10 μg/ml Cry2Ab2 (n=200) and 100% mortality in tests of 10 μg/ml Cry2Ab2 (n=120). Field evaluations of efficacy of Bt cotton were conducted by the Arizona Cotton Research and Protection Council in adjacent pairs of Bt and non-Bt fields at 44 Arizona locations. Statewide, large pink bollworm larvae were found in an average of 15% of non-Bt bolls sampled from borders of refuge fields. This was on the low end of the range of infestation levels observed in refuges during the past decade. Bolls from adjacent Bt cotton (Bollgard™) fields yielded an average of 0.28% infested bolls. This value was down slightly from the previous year. Over 70% of the pink bollworm recovered from collections in Bt fields were from bolls that did not express Bt toxin. We conclude that there was no indication of problems with pink bollworm resistance to Cry1Ac or Cry2Ab2 at the locations sampled in 2005. Moreover, Bt cotton continued to exhibit exceptional field performance in Arizona.

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Sims, Maria A., Timothy J. Dennehy, Amanda Patin, Yves Carrière, Yong-Biao Liu, Bruce Tabashnik, Larry Antilla e Mike Whitlow. "Arizona's Multi-agency Resistance Management Program for Bt Cotton: Sustaining the Susceptibility of Pink Bollworm". College of Agriculture, University of Arizona (Tucson, AZ), 2001. http://hdl.handle.net/10150/211325.

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Bt cotton has been used in Arizona since 1996 with exceptionally positive results in terms of economic returns to growers and reductions in insecticide use in cotton. Yet, the isolation of pink bollworm highly resistant to Bt cotton from collections made in Arizona in 1997 demonstrated the seriousness of the threat that resistance poses to transgenic Bt technology. For this reason unparalleled measures have been taken to detect and manage resistance of pink bollworm to Bt cotton in Arizona. This paper presents results of statewide monitoring of pink bollworm susceptibility to the Bt toxin, Cry1Ac, conducted from 1997 to 1999. Mean susceptibility of Arizona pink bollworm to Cry1Ac increased from 1997 to 1999. Mean corrected mortality in 1μg/ml Cry1Ac assays was 52.3% in 1997, 90.6% in 1998, and 97.9% in 1999. Mean corrected mortality in bioassays of 10 μg/ml was 94.5% in 1997, 99.8% in 1998, and 100% in 1999. Selection with Cry1Ac in the laboratory has produced from 1997 field collections a strain possessing 200 to 900-fold resistance to Cry1Ac. This resistant strain is capable of surviving on Bt cotton. We provide an overview of other components of the multi-agency collaboration to sustain efficacy of Bt cotton in Arizona. These include: 1) evaluation of the field performance of Bt cotton; 2) mapping and analysis of use of Bt and non-Bt cotton and compliance with refuge requirements; 3) effectiveness of internal versus external refuges and movement of pink bollworm moths from refuges; and 4) activities of the Arizona Bt Cotton Working Group to formulate and implement effective resistance management strategies.

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Heuberger, Shannon Marlene. "Contamination of Refuges by Transgenic Bt Cotton: Implications for Pink Bollworm (Lepidoptera: Gelechiidae) Resistance". Thesis, The University of Arizona, 2006. http://hdl.handle.net/10150/193364.

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Refuges of non-Bt cotton are used to delay Bt resistance in the pink bollworm (Pectinophora gossypiella, Lepidoptera: Gelechiidae), a pest that eats cotton seeds. Contamination of refuges by transgenic Bt cotton could threaten the efficacy of such refuges by increasing the relative survival of larvae that carry alleles for Bt resistance. Here I compared contamination levels in refuges of varying configuration and distance from Bt. I found two types of contamination at low rates in refuges: outcrossing by Bt pollen and adventitious Bt plants. Unexpectedly, outcrossing did not differ between refuge configurations, and did not decrease as distance from Bt fields increased, perhaps because Bt plants in refuges acted as the main Bt pollen source. Bioassays, conducted to evaluate the impacts of contamination on pink bollworm resistance, indicated that Bt plants in refuges may increase the frequency of resistance alleles at a higher rate than outcrossing by Bt plants.

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Knowles, Tim C., Tim J. Dennehy e Albert Rovey. "Late Season Pink Bollworm Pressure in the Top Crop of Bt and Non-Bt Cotton". College of Agriculture, University of Arizona (Tucson, AZ), 1998. http://hdl.handle.net/10150/210372.

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Green bolls (100/field) were sampled from the uppermost internodes within adjacent fields of Bt (Deltapine 33B) and non-Bt (Hyperformer HS 44) cotton experiencing severe pink bollworm pressure late in the growing season. Average top crop lint yield reductions ranging from 30 to 70% were observed in the uppermost bolls of the non-Bt cotton variety. Average top crop lint yield reductions ranging from 0 to 40% were observed in the uppermost bolls of the transgenic Bt cotton variety.

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McGinley, Susan. "Bt Cotton and Pink Bollworm: A Cooperative Research and Education Program". College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2001. http://hdl.handle.net/10150/622253.

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Wilson, F. D., e H. M. Flint. "Evaluation of Cotton for Resistance to Pink Bollworm". College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/208329.

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Cotton cultivars and germ plasm lines were screened for resistance to pink bollworm. Sixteen advanced strains were selected for resistance to pink bollworm and/or high yield potential. In a regional early maturing germ plasm lines test, only the short- season check had less seed damage caused by pink bollworm than did the long-season check. Five lines yielded more lint than both checks. In a Pima test, Pima S-6 nectariless had 14% less seed damage than Pima S-6. Seven pink-bollworm-resistant germ plasm lines will be released in the near future.

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Green bolls (100/field) were sampled from the uppermost internodes within adjacent fields of Bt (Deltapine 33B) and non-Bt refuge (Hyperformer HS 44 or Deltapine 20) experiencing severe pink bollworm pressure late in the growing season. Evidence of 3rd instar or larger pink bollworm larvae survival was higher in susceptible bolls sampled from transgenic Bt cotton late in the 1998 growing season, compared to that observed late in the 1997 growing season.

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Howell, Don R., John Palumbo, Alfonso Tellez e Humberto Hernandez. "Demonstration to Manage Pink Bollworm with BT Cottons, Yuma Valley Ag Center, 1996". College of Agriculture, University of Arizona (Tucson, AZ), 1997. http://hdl.handle.net/10150/211104.

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Transgenic cotton with the Bollgard™ gene inserted has shown great promise in controlling pink bollworm infestations in cotton. This trial was superimposed over a variety trial. Evaluations of pbw infestation indicated remarkable control even though the bolls became infested. Yields were increased in this trial when almost 100% infestation of pbw was allowed to occur. It appears that the trangenic cottons containing Bollgard™ may be an effective method of pbw control.

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Watson, Theo F., e Suzanne E. Kelly. "Status of Pink Bollworm Resistance to Insecticides in Arizona". College of Agriculture, University of Arizona (Tucson, AZ), 1991. http://hdl.handle.net/10150/208371.

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Populations of pink bollworm. Pectinophora gossypiella (Saunders), from Yuma, Casa Grande, Marana and Safford were compared with that of a susceptible laboratory (USDA) strain relative to their susceptibility to permethrin. A limited comparison was made with azinphosmethyl. All field strains were significantly more tolerant to permethrin than was the USDA susceptible strain. A comparison of the USDA and Yuma strains using azinphosmethyl indicated no difference in susceptibility between the laboratory and field strains.

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Livros sobre o assunto "Pink bollworm resistance to Bt Cotton"

Wilson, Floyd D. Innovations in the X-ray technique of evaluating cotton germplasm for resistance to pink bollworm. [Washington, D.C.?]: U.S. Dept. of Agriculture, Agricultural Research Service, 1985.

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W, George B., e United States. Agricultural Research Service., eds. Innovations in the X-ray technique of evaluating cotton germplasm for resistance to pink bollworm. [Washington, D.C.?]: U.S. Dept. of Agriculture, Agricultural Research Service, 1985.

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Pathak, Dharminder, Satnam Singh, Harish Kumar, Gomti Grover e Navneet Kaur, eds. Cotton Some: Insights. The Crop Improvement Society of India, 2023.

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Innovations in the X-ray technique of evaluating cotton germplasm for resistance to pink bollworm. [Washington, D.C.?]: U.S. Dept. of Agriculture, Agricultural Research Service, 1985.

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Capítulos de livros sobre o assunto "Pink bollworm resistance to Bt Cotton"

Deshmukh, J. M., e B. Y. Ghuge. "Analysis of Profile of Bt Cotton Growers with their Adoption of IPM Practices for Controlling Pink Bollworm". In Emerging Issues in Agricultural Sciences Vol. 1, 11–16. B P International (a part of SCIENCEDOMAIN International), 2023. http://dx.doi.org/10.9734/bpi/eias/v1/17697d.

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Trabalhos de conferências sobre o assunto "Pink bollworm resistance to Bt Cotton"

Mathew, Lolita G. "Genetic basis of resistance to Bt toxin Cry2Ab in pink bollworm, Pectinophora gossypiella". In 2016 International Congress of Entomology. Entomological Society of America, 2016. http://dx.doi.org/10.1603/ice.2016.115187.

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Yang, Yihua. "Selection with Cry2Ab confers broad-spectrum resistance to Bt Cry toxins in cotton bollworm,Helicoverpa armigera". In 2016 International Congress of Entomology. Entomological Society of America, 2016. http://dx.doi.org/10.1603/ice.2016.113472.

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Relatórios de organizações sobre o assunto "Pink bollworm resistance to Bt Cotton"

Harari, Ally R., Russell A. Jurenka, Ada Rafaeli e Victoria Soroker. Evolution of resistance to mating disruption in the pink bollworm moth evidence and possible mechanism. United States Department of Agriculture, janeiro de 2014. http://dx.doi.org/10.32747/2014.7598165.bard.

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t The pink bollworm, Pectinophoragossypiellais a key pest of cotton world-wide. In Israel mating disruption sex pheromone is used in all cotton fields and recent repeated outbreaks of the pest populations has suggested a change in the population sex pheromone characteristics. The research goals were to (1) determine the change in pheromone characteristic of PBW females after long experience to Mating Disruption (MD), (2) to test the male’s antennae response (EAG) to pheromone characteristics of laboratory, naive females, and of field collected, MD experienced females, (3) to analyse the biosynthetic pathway for possible enzyme variations, (4) to determine the male behavioural response to the pheromone blend involved in the resistance to MD. The experiments revealed that (1) MD experienced females produced pheromone blend with higher ZZ ratio than lab reared (MD naive females) that typically produced ZZ:EE ratio of 1:1. (2) Male’s origin did not affect its response to pheromone characteristics of lab or field females. (3) A transcriptome study demonstrated many gene-encode enzymes in the biosynthetic pathway, but some of the transcripts were produced in differing levels in the MD resistant populations. (4) Male origin (field or lab) influenced males’ choice of mate with strong preference to females sharing the same origin. However, when MD was applied, males of both populations were more attracted to females originated form failed MD treated fields. We conclude that in MD failed fields a change in the population mean of the ratio of the pheromone components had occurred. Males in these fields had changed their search “image” accordingly while keeping the wide range of response to all pheromone characteristics. The change in the pheromone blend is due to different level of pheromone related enzyme production.

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