Non-transgenic Cotton Research Articles

From genes to fields: Environmental compatibility of herbicide tolerant transgenic cotton

IntroductionThere are several enticing reasons to use genetic engineering to develop transgenic cotton plants with economically relevant new traits. The use of transgenic cotton to protect crops from biotic stressors like weeds may prove to be a cost-effective solution. ObjectivesThe development of herbicide-resistant cotton variants is the primary motivation for gene transfer in this crop. In the current study, we conducted a battery of experiments on the herbicide-tolerant cotton variety MNH-786 to investigate its expression patterns and environmental adaptation. Material and methodsThe 35S promoter controls the expression of the codon-optimized Cp4-EPSPS gene that is present in this variety. Several different molecular approaches, such as polymerase chain reaction (PCR), Florescent In-Situ Hybridization analysis, and enzyme-linked immunosorbent assay (ELISA), are used to confirm the presence of transgenic cotton plants. The glyphosate spray assay was performed using molecular analysis, employing a dosage of 2000 ml per acre. The suitability of transgenic and non-transgenic cotton plants in four unique environments—the Multan, Vehari, Bahawalpur, and Faisalabad Districts of Punjab province, Pakistan was assessed using a comparative comparison. A gene x environment interaction (GEI) biplot was used to analyze the correlation between genes and their environments. ResultsTransgenic cotton plants screened using PCR to target 1.467 kb regions showed effective integration into cotton genomes. Results showed that Cp4-EPSPS proteins fluctuated and associated with environmental variables across all three generations (T0, T1, and T2). In the herbicide spray assay, all transgenic cotton plants survived, but non-transgenic cotton and all weeds died. According to the "which-won-where" polygon, transgenic cotton plant Events 3, 4, 5, 6, and 7 performed better in three settings, except Faisalabad. According to correlation and heat-map yield research, transgenic cotton variety MNH-786 Events 4, 5 and 6 have a higher consistency and influence in Vehari district's natural habitats. Multan and Bahawalpur also show encouraging results. In Faisalabad, no transgenic events perform well. ConclusionWe conclude that Events 4 and 5 show a substantial abundance of genetic potential that is robust over a wide range of environments thanks to our thorough study of the outcomes obtained under these conditions. SignificanceOur study emphasises the importance of transgenic cotton, its performance, and its exposure to appropriate agroecological zones. This knowledge can be advantageous for farmers in attaining optimal conditions to maximize productivity.

Differentiation of the Pathotypes in Race 29 of cotton Bacterial Leaf Blight Pathogen Xanthomonas axonopodis pv. malvacearum (Xam) and the reaction of some transgenic ( Bt ) and non-transgenic cotton varieties grown in Vidharbha region to the prevalent Xam races and pathotypes.

Differentiation of the Pathotypes in Race 29 of cotton Bacterial Leaf Blight Pathogen Xanthomonas axonopodis pv. malvacearum (Xam) and the reaction of some transgenic ( Bt ) and non-transgenic cotton varieties grown in Vidharbha region to the prevalent Xam races and pathotypes.

Development and reproduction of Tetranychus cinnabarinus (Acari: Tetranychidae) on transgenic insect-resistant cotton cultivars

Effects of transgenic insect-resistant Bt cotton Zhongkangza 5 and Lumianyan 23 and Bt + CpTI cotton sGK958 and Zhongmiansuo 45 on Tetranychus cinnabarinus growth and reproduction were compared with those of nontransgenic cotton (K836) under laboratory conditions. Developmental times of different T. cinnabarinus stages fed on transgenic Bt and Bt + CpTI cotton differed significantly from those fed on K836. Pre-oviposition (1.44 d) and oviposition (12.71 d) periods and female life span (14.11 d) were longer on K836 than on transgenic cotton. Maximum fecundity was 75.61 eggs per female on K836, while minimum fecundity was 54.68 eggs per female on sGK958. Net reproductive rate was highest with 55.00 female offspring on K836, whereas the lowest was 37.219 female offspring on Zhongkangza 5. The highest intrinsic rate of increase was 0.454 day−1 on K836, whereas the lowest was 0.246 day−1 on Zhongkangza 5. The highest finite rate of increase was 1.575 day−1 on K836, whereas the lowest was 1.278 day−1 on Zhongkangza 5. The shortest population doubling time was 1.526 d on K836, while the longest was 2.823 d on Zhongkangza 5. Thus, transgenic cotton inhibited T. cinnabarinus development and reproduction, indicating transgenic cotton could prevent damage by T. cinnabarinus or other pests.

Effects of multi-resistant ScALDH21 transgenic cotton on soil microbial communities

Transgenic crops are increasingly prevalent worldwide, and evaluating their impact on soil microbial communities is a critical aspect of upholding environmental safety. Our previous research demonstrated that overexpression of ScALDH21 from desiccant-tolerant moss, Syntrichia caninervis, in cotton revealed multi-resistance to drought, salt, and biotic stresses. We conducted metabarcoding using high-throughput sequencing to evaluate the effect of ScALDH21 transgenic cotton on soil microbial communities. We further conducted soil tests to analyze the chemical properties of transgenic and non-transgenic cotton, including the total content and availability of chemical elements (K, P, and N), organic matter, and pH value. Both transgenic and non-transgenic cotton fields exhibited soil pH values higher than 8. The presence of transgenic cotton significantly enhanced the availability of available K and the total content of total P in the soil. Alpha and beta diversity indices of soil microbiota showed no difference between two transgenic and non-transgenic cotton groups. Dominant clades of fungal and bacterial genera were equivalent at the phylum and genus levels in all three groups. The correlation analysis of microbial communities and soil environmental factors revealed the absence of significant differences between transgenic and non-transgenic cotton genotypes. Functional predictions of soil microbial communities indicated that microbial community function did not show significant differences between transgenic and non-transgenic cotton samples. These findings are essential for evaluating the environmental effects of transgenic crops and supporting the secure implementation of transgenic cotton.

Prickly Sida (Sida spinosa L.) and Cotton Response to Pre- and Early Post-Emergence Herbicides

Prickly sida is a troublesome annual weed native to the USA. It was introduced in Greece over two decades ago and has since been infesting cotton crops, where it proved difficult to control. A two-year field study (2021–2022) was conducted in a cotton field (Karditsa, central Greece) heavily infested with prickly sida to evaluate the efficacy of nine treatments against this weed, using pre-emergence (PRE) and early post-emergence (EPOST) herbicides applied at the field rate. At 8 weeks after treatment, prickly sida control was over 90% with pyrithiobac PRE (68.9 g ai ha−1) alone or in mixture with s-metolachlor (960 g ai ha−1) or with isoxaben (150 g ai ha−1) and with the application of pyrithiobac + s-metolachlor PRE (34.5 + 960 g ai ha−1) followed by pyrithiobac EPOST (34.5 g ai ha−1). Flurochloridone + fluometuron PRE (375 + 2000 g ai ha−1), flumioxazin + s-metolachlor PRE (50 + 960 g ai ha−1), or pendimethalin + terbuthylazine PRE (1500 + 750 g ai ha−1) controlled prickly sida by 89–93% in 2021 and 82–90% in 2022. Pyrithiobac EPOST alone or in mixture with trifloxysulfuron did not adequately control prickly sida. Yield was significantly lower in the weedy check and EPOST compared with the PRE treatments. None of the herbicides caused any visual injury to the crop or any reduction in cotton density. Our results can help in the successful management of prickly sida in non-transgenic cotton to maximize cotton yield and quality.

A nonsynonymous mutation in an acetolactate synthase gene (Gh_D10G1253) is required for tolerance to imidazolinone herbicides in cotton

BackgroundHerbicide tolerance in crops enables them to survive when lethal doses of herbicides are applied to surrounding weeds. Herbicide-tolerant crops can be developed through transgenic approaches or traditional mutagenesis approaches. At present, no transgenic herbicide tolerant cotton have been commercialized in China due to the genetically-modified organism (GMO) regulation law. We aim to develop a non-transgenic herbicide-tolerant cotton through ethyl methanesulfonate (EMS) mutagenesis, offering an alternative choice for weed management.ResultsSeeds of an elite cotton cultivar Lumianyan 37 (Lu37) were treated with EMS, and a mutant Lu37-1 showed strong tolerance to imidazolinone (IMI) herbicides was identified. A novel nonsynonymous substitution mutation Ser642Asn at acetolactate synthase (ALS) (Gh_D10G1253) in Lu37-1 mutant line was found to be the potential cause to the IMI herbicides tolerance in cotton. The Ser642Asn mutation in ALS did not present among the genomes of natural Gossypium species. Cleaved amplified polymorphic sequence (CAPS) markers were developed to identify the ALS mutant allele. The Arabidopsis overexpressing the mutanted ALS also showed high tolerance to IMI herbicides.ConclusionThe nonsynonymous substitution mutation Ser642Asn of the ALS gene Gh_D10G1253 is a novel identified mutation in cotton. This substitution mutation has also been identified in the orthologous ALS genes in other crops. This mutant ALS allele can be used to develop IMI herbicide-tolerant crops via a non-transgenic or transgenic approach.Graphical abstract

Transcriptome Reveals the Molecular Mechanism of the ScALDH21 Gene from the Desert Moss Syntrichia caninervis Conferring Resistance to Salt Stress in Cotton.

The desert moss Syntrichia caninervis has proven to be an excellent plant material for mining resistance genes. The aldehyde dehydrogenase 21 (ScALDH21) gene from S. caninervis has been shown to confer tolerance to salt and drought, but it is unclear how the transgene ScALDH21 regulates tolerance to abiotic stresses in cotton. In the present work, we studied the physiological and transcriptome analyses of non-transgenic (NT) and transgenic ScALDH21 cotton (L96) at 0 day, 2 days, and 5 days after salt stress. Through intergroup comparisons and a weighted correlation network analysis (WGCNA), we found that there were significant differences between NT and L96 cotton in the plant hormone, Ca2+, and mitogen-activated protein kinase (MAPK) signaling pathways as well as for photosynthesis and carbohydrate metabolism. Overexpression of ScALDH21 significantly increased the expression of stress-related genes in L96 compared to NT cotton under both normal growth and salt stress conditions. These data suggest that the ScALDH21 transgene can scavenge more reactive oxygen species (ROS) in vivo relative to NT cotton and improve cotton resistance to salt stress by increasing the expression of stress-responsive genes, responding quickly to stress stimuli, enhancing photosynthesis and improving carbohydrate metabolism. Therefore, ScALDH21 is a promising candidate gene to improve resistance to salt stress, and the application of this gene in cotton provides new insights into molecular plant breeding.

Engineering of cry genes “Cry11 and Cry1h” in cotton (Gossypium hirsutum L.) for protection against insect pest attack

Cotton is white gold and contributes significantly to the economy of the countries. The process of evolution of resistance in various cotton insects directly affects the life of people. Among the cotton insect pests, pink bollworm (Pectinophora gossypiella) and army bollworm (Spodoptera litura) have turned out to be destructive. The development of seed using gene stacking approach has tremendously reduced the applications of agrochemicals making the technology greener for society. A gene cassette containing Cry11 and Cry1H genes was constructed. The cassette was cloned into the pCAMBIA2300 plant expression vector using the CAMV3-35S promoter. The construct was transformed into cotton line FBS-222 using the shoot apex-cut Agrobacterium-mediated transformation method. The expression of the Cry genes was 3-fold higher in transgenic than the non-transgenic cotton plants using qRT-PCR. Finally, the insect bioassay with transgenic cotton showed 90% mortality against pink bollworms and 80% against cotton army bollworms. The results demonstrate the development of seeds using the gene pyramiding approach is an effective strategy to control insect pest attacks.

Influence of Transgenic (Bt) Cotton on the Productivity of Various Cotton-Based Cropping Systems in Pakistan

Cotton (Gossypium hirsutum L.) is an important fiber crop in Pakistan with significant economic importance. Transgenic, insect-resistant cotton (carrying a gene from Bacillus thuringiensis (Bt)) was inducted in the cotton-based cropping systems of Pakistan during 2002, and is now sown in >90% of cotton fields in the country. However, concerns are rising that Bt cotton would decrease the productivity of winter crops (sown after cotton), leading to decreased system productivity. This two-year field study determined the impacts of transgenic (Bt) and non-transgenic (non-Bt) cotton genotypes on the productivities of winter crops (i.e., wheat, Egyptian clover, and canola), and the overall productivities of the cropping systems including these crops. Four cotton genotypes (two Bt and two non-Bt) and three winter crops (i.e., wheat, Egyptian clover, and canola) were included in the study. Nutrient availability was assessed after the harvest of cotton and winter crops. Similarly, the yield-related traits of cotton and winter crops were recorded at their harvest. The productivities of the winter crops were converted to net economic returns, and the overall economic returns of the cropping systems with winter crops were computed. The results revealed that Bt and non-Bt cotton genotypes significantly (p < 0.05) altered nutrient availability (N, P, K, B, Zn, and Fe). However, the yield-related attributes of winter crops were not affected by cotton genotypes, whereas the overall profitability of the cropping systems varied among the cotton genotypes. Economic analyses indicated that the Bt cotton–wheat cropping system was the most profitable, with a benefit–cost ratio of 1.55 in the semi-arid region of Pakistan. It is concluded that Bt cotton could be successfully inducted into the existing cropping systems of Pakistan without any decrease to the overall productivity of the cropping system.

Development and reproduction of Tetranychus cinnabarinus (Acari: Tetranychiae) on transgenic insect-resistant cotton plants

The effects of two insect-resistant transgenic cotton strains (transgenic Bt pest-resistant cotton Zhongkangza 5 and Lumianyan 23, transgenic Bt+CpTI pest-resistant cotton sGK958 and Zhongmiansuo 45) on the growth and reproduction of Tetranychus cinnabarinus was examined in comparison with non-transgenic cotton (K836) at 70% relative humidity and 30±0.5 ℃. The results showed that T. cinnabarinus fed on transgenic Bt cotton and transgenic Bt+CpTI cotton differed significantly from those on conventional cotton in development time of various stages. Furthermore, the development times of mites on transgenic Bt cotton and transgenic Bt+CpTI cotton were the same, but the development times of T. cinnabarinus fed on transgenic Bt pest-resistant cotton Zhongkangza 5 and Lumianyan 23 were different, as well as the development times of T. cinnabarinus fed on transgenic Bt+CpTI pest-resistant cotton sGK958 and Zhongmiansuo 45. The pre-oviposition period, oviposition period and the female mite life span were longer (1.44 d, 12.71 d, and 14.11 d respectively) on non-transgenic cotton than on transgenic cotton. The maximum fecundity was 75.61 eggs per female on non-transgenic cotton and the minimum fecundity (54.68 eggs per female) was observed in mites fed on sGK958. The net reproductive rate (R0) was the highest (55.000) on non-transgenic cotton, but was the smallest (37.219) on Zhongkangza 5. The intrinsic rate of increase (rm) was the highest (0.454) on non-transgenic cotton, but was the smallest (0.246) on Zhongkangza 5. The finite rate of increase (λ) was the highest (1.575) on non-transgenic cotton, but was the smallest (1.278) on Zhongkangza 5. The population doubling time (DT) was the shortest (1.526 d) on non-transgenic cotton, but was the longest (2.823 d) on Zhongkangza 5. The results of this study indicated the negative effects of transgenic cotton on the development and reproduction of T. cinnabarinus was significant: the larvae had the lowest survival rate after feeding on five kinds of cotton, while deutonymphs had the highest survival rate; the hatching rate and deutonymph survival rate of T. cinnabarinus fed on CK were the highest, while the hatching rate and larval survival rate of the sGK958 were the lowest. Transgenic insect-resistant cotton basically showed significant effects on the development period of each stage and the whole generation of T. cinnabarinus, but there were no significant differences between univalent transgenic Bt cotton and bivalent transgenic Bt+CpTI cotton.

Retraction: The influence of transgenic (Bt) and non-transgenic (non-Bt) cotton mulches on weed dynamics, soil properties and productivity of different winter crops.

Retraction: The influence of transgenic (Bt) and non-transgenic (non-Bt) cotton mulches on weed dynamics, soil properties and productivity of different winter crops.

Development and evaluation of triple gene transgenic cotton lines expressing three genes (Cry1Ac-Cry2Ab-EPSPS) for lepidopteran insect pests and herbicide tolerance

Cotton is an international agricultural commodity and the main cash crop of Pakistan of which quality and quantity are subject to various whims of nature. Climate change, insect pest complex, and weeds are reducing its productivity. Here, we have developed triple gene cotton containing EPSPS gene along with two Bt toxin genes Cry1Ac and Cry2Ab using a strategy where all three genes are cloned in the same T-DNA, followed by successful cotton transformation via Agrobacterium-mediated transformation. This strategy has been developed to help cotton breeders in developing new cultivars by incorporating these genes into the non-transgenic or single Bt (Cry1Ac) gene cotton background where all three genes will inherit together. The expression of all three proteins was confirmed through immunostrips and was quantified through enzyme-linked immunosorbent assay (ELISA). The spatio-temporal expression of Bt protein in different parts of triple gene NIBGE cotton plants was determined. Maximum expression was found in leaves followed by seeds and boll rinds. Insect bioassays with cotton bollworms (Helicoverpa armigera), armyworms (Spodoptera litura), and pink bollworms (Pectinophora gossypiella) showed more than 90% mortality. The best performing line (NIBGE-E2) on the basis of spatiotemporal expression, glyphosate assays, and insect mortality data, was used for event characterization by using the genome sequencing approach. The event was successfully characterized and named NIBGE 20-01. A diagnostics test based on event-specific PCR was developed and its ability to distinguish NIBGE 20-01 event from other commercial transgenic cotton events was confirmed. To confirm stable expression of all three proteins in the field conditions, homozygous transgenic lines were grown in the field and the expression was confirmed through immunostrip assays. It was found that all three genes are expressed under field conditions. To show that all three genes are inherited together upon crossing with local elite cotton lines, the F1 generation was grown under glasshouse and field conditions. The expression of all three genes was confirmed under field conditions. Our results showed that transgenic cotton with three genes cloned in the same T-DNA can express all genes and can be conveniently transferred into elite cotton lines through a single cross.

Effects of transgenic cotton lines expressing dsAgCYP6CY3-P1 on the growth and detoxification ability of Aphis gossypii glover.

The pest Aphis gossypii Glover globally causes considerable economic losses on various crops by its feeding damage and disease transmission. Transgenic plants that produce double-stranded RNA (dsRNA) targeted to insect genes are being developed as a pest control strategy. In this study, we evaluated the effects of transgenic cotton-mediated RNA interference (RNAi) on the growth and detoxification ability of A. gossypii after the transgenic cotton lines expressing dsAgCYP6CY3-P1 (the TG cotton lines) were obtained on the basis of exploring the functions of CYP6CY3 in our previous research. The developmental time of third- and fourth-instar nymphs which fed on the TG cotton lines were significantly prolonged. Life table parameters showed that the fitness of cotton aphids from the TG cotton lines decreased. Additionally, the relative expression level of CYP6CY3 in cotton aphids which fed on the TG cotton lines was significantly reduced by 47.3 % at 48 h compared with that from the nontransgenic cotton (the NT cotton). Bioassay showed that silencing of CYP6CY3 increased mortality of the nymphs to imidacloprid by 28.49 % (at 24 h) and to acetamiprid by 73.77 % (at 48 h), respectively. These results indicated that the TG cotton lines delayed the growth and development of A. gossypii, but also decreased population density and increased its sensitivity to imidacloprid and acetamiprid, respectively. The results provide further support for the development and application of plant-mediated RNAi. © 2022 Society of Chemical Industry.

Large-scale evaluation of physical drift and volatility of 2,4-D choline in cotton: a four-year field study.

Cotton with resistance to 2,4-d choline, glufosinate and glyphosate allows over-the-top use of these herbicides for postemergence weed control. Nontransgenic cotton is highly responsive to low rates of 2,4-d, causing concern among farmers when the herbicide is applied near the crop. Injury to nearby cotton following application of 2,4-d choline is sometimes blamed on volatilization of the herbicide. A large-scale experiment was conducted in 2018-2021 to better understand causes of damage to nearby sensitive cotton following an application of 2,4-d choline plus glufosinate-ammonium. The herbicides were applied to 0.4ha in the center of a 4-ha non-Enlist cotton field. At 30 min after application, air samplers were established in the treated center and outside the treated area in cardinal directions. The 72-h cumulative air concentration of 2,4-d in the swath ranged from 3.3 to 7.1ng m-3 , and most volatile residues (5.0-25.5ng m-3 ) were detected in samplers established in the downwind direction directly adjacent to the treated field. Cotton plants in three downwind transects that were covered for 30 min after application were not damaged by 2,4-d, whereas noncovered plants along the downwind transects were injured. No cotton injury occurred outside the treated area, except in the downwind direction during application even though wind direction changed after application. 2,4-d choline volatilizes, but findings show that the volatilization is not sufficient to damage cotton in the neighboring area following applications, pointing to the importance of applicators understanding wind direction/shift during the application along with proximity of sensitive crops in the downwind direction. © 2022 Society of Chemical Industry.

Engineered resistance and risk assessment associated with insecticidal and weeds resistant transgenic cotton using wister rat model

Stacking multiple genes into cotton crop to cop up multiple biotic stresses such as insects and weeds is a promising tool to save crop from losses. Transgenic cotton variety, VH-289, with double Bt and cp4EPSPS genes under the control of 35S promoter was used for the expression analyses and biosafety studies. The transgenic cotton plants were screened through PCR amplification of fragments, 1.7 kb for Cry1Ac, 582 bp for Cry2A and 250 bp for cp4EPSPS; which confirmed the presence of all genes transformed in transgenic cotton. The Cry1Ac + Cry2A and cp4EPSPS proteins were quantified through ELISA in transgenic cotton plants. The Glyphosate assay performed by spraying 1900 mL per acre of glyphosate Roundup further confirmed complete survival of transgenic cotton plants as compared to the non-transgenic cotton plants and all weeds. Similarly, insect infestation data determined that almost 99% insect mortality was observed in controlled field grown transgenic cotton plants as compared to the non-transgenic control plants. Evaluation of effect of temperature and soil nutrients availability on transgene expression in cotton plants was done at two different cotton growing regions, Multan and Lahore, Pakistan and results suggested that despite of higher temperature in Multan field, an increased level of Cry and cp4EPSPS proteins was recorded due to higher soil organic matter availability compared to Lahore field. Before commercialization of any transgenic variety its biosafety study is mandatory so, a 90 days biosafety study of the transgenic cotton plants with 40% transgenic cottonseeds in standard diet showed no harmful effect on wister rat model when studied for liver function, renal function and serum electrolyte.

Effect of weather factors on the population dynamics of sucking insect pests and their natural enemies in transgenic and non-transgenic cotton

Effect of weather factors on the population dynamics of sucking insect pests and their natural enemies in transgenic and non-transgenic cotton

Transformation and Overexpression of Primary Cell Wall Synthesis-Related Zinc Finger Gene Gh_A07G1537 to Improve Fiber Length in Cotton.

Molecular interventions have helped to explore the genes involved in fiber length, fiber strength, and other quality parameters with improved characteristics, particularly in cotton. The current study is an extension and functional validation of previous findings that Gh_A07G1537 influences fiber length in cotton using a chromosomal segment substitution line MBI7747 through RNA-seq data. The recombinant Gh_A07G1537 derived from the MBI7747 line was over-expressed in CCRI24, a genotype with a low profile of fiber quality parameters. Putative transformants were selected on MS medium containing hygromycin (25mg/ml), acclimatized, and shifted to a greenhouse for further growth and proliferation. Transgene integration was validated through PCR and Southern Blot analysis. Stable integration of the transgene (ΔGh_A07G1537) was validated by tracking its expression in different generations (T0, T1, and T2) of transformed cotton plants. It was found to be 2.97-, 2.86-, and 2.92-folds higher expression in T0, T1, and T2 plants, respectively, of transgenic compared with non-transgenic cotton plants. Fiber quality parameters were also observed to be improved in the engineered cotton line. Genetic modifications of Gh_A07G1537 support the improvement in fiber quality parameters and should be appreciated for the textile industry.

Transgenic Cry1Ac + CpTI cotton does not compromise parasitoid-mediated biological control: An eight-year case study.

The on-farm deployment of genetically modified crops may negatively affect nontarget arthropods, potentially disrupting food web structure and ecosystem functions. Aphid-parasitoid interactions are well-suited to study these potential impacts in agro-ecosystems. Over the span of 8 years, we systematically compared infestation levels of the aphid Aphis gossypii, its associated parasitoid community and overall parasitism rate between transgenic Cry1Ac + CpTI cotton and nontransgenic cotton. Furthermore, we measured the impact of transgenic Cry1Ac + CpTI cotton on structural traits and interspecies interactions within quantitative aphid-parasitoid food webs. Transgenic Cry1Ac + CpTI cotton did not affect the abundance of aphids and parasitoids, or in-field parasitism rates. Despite weak interannual variability, transgenic Cry1Ac + CpTI cotton also did not alter food web architecture or biological control services. Our work not only elucidates the impact of transgenic Cry1Ac + CpTI cotton on different nontarget arthropods (i.e. aphids, parasitoids, hyperparasitoids) and their associated ecosystem services or disservices, but also diversifies the ecological risk assessment toolbox for transgenic insecticidal crops. © 2021 Society of Chemical Industry.

Susceptibility of Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) on detached plant parts of transgenic and non-transgenic cotton

Susceptibility of Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) on detached plant parts of transgenic and non-transgenic cotton

Comparative study of transgenic and nontransgenic cotton

AbstractThe environmental impact of genetically modified crops has been extensively investigated. However, few reports on the influence of transgenic traits on genetic structure have been reported in the literature. It is unknown how or if transgenic cultivars have affected genotypic variation in upland cotton (Gossypium hirsutum L.) since its rise to dominance in cotton production. In this study, the genotypic variance components, g, of lint yield (LY) and fiber quality were compared among transgenic and nontransgenic cotton in the USDA Regional High Quality (RHQ) tests from 2002 through 2018. The popular transgenic and nontransgenic cultivars/lines developed by the major private and public cotton breeding programs in the United States during this period were included. Testing cycles within the RHQ protocol consist of standardized control cultivars plus experimental entries. Variance components were dissected in each testing year within six such testing cycles. Lint yield of the transgenic cotton was generally higher than nontransgenic cotton. Fiber quality of the nontransgenic cotton was generally higher than the transgenic cotton. For LY, the proportion of g to the total variance was lower in the transgenic cotton than in the nontransgenic cotton, but the difference diminished in the recent two cycles. The proportion of g was lower in the transgenic cotton compared with the nontransgenic cotton for fiber length, fiber strength, fiber uniformity, and micronaire. The discrepancy between the two types of cotton in the RHQ tests reflects the influences of differential breeding schemes in the private and public breeding programs on means and genotypic variance of LY and fiber quality.