scholarly journals Transgenic IR72 with Fused Bt Gene cry1Ab/cry1Ac from Bacillus thuringiensis is Resistant Against Four Lepidopteran Species Under Field Conditions

2001 ◽  
Vol 18 (2) ◽  
pp. 125-133 ◽  
Author(s):  
Gong-yin YE ◽  
Jumin TU ◽  
Cui HU ◽  
K. DATTA ◽  
S. K. DATTA
Keyword(s):  
Bacillus Thuringiensis ◽  
Field Conditions ◽  
Lepidopteran Species ◽  
Bt Gene

Explaining contradictory evidence regarding impacts of genetically modified crops in developing countries. Varietal performance of transgenic cotton in India

2005 ◽  
Vol 143 (1) ◽  
pp. 35-41 ◽  
Author(s):  
R. BENNETT ◽  
Y. ISMAEL ◽  
S. MORSE
Keyword(s):  
Developing Countries ◽  
Bacillus Thuringiensis ◽  
Genetically Modified Crops ◽  
Transgenic Cotton ◽  
Hybrid Vigour ◽  
Bt Cotton ◽  
Yield Performance ◽  
Contradictory Evidence ◽  
Bt Gene ◽  
Better Than

A study of the commercial growing of different varieties of Bacillus thuringiensis (Bt) cotton compares the performance of growing official and unofficial hybrid varieties of Bt cotton and conventional (non-Bt) hybrids in Gujarat by 622 farmers. Results suggest that the official Bt varieties (MECH 12 and MECH 162) significantly outperform the unofficial varieties. However, unofficial, locally produced Bt hybrids can also perform significantly better than non-Bt hybrids, although second generation (F2) Bt seed appears to have no yield advantage compared to non-Bt hybrids but can save on insecticide use. Although hybrid vigour is reduced, or even lost, with F2 seed the Bt gene still confers some advantage. The F2 seed is regarded as ‘GM’ by the farmers (and is sold as such), even though its yield performance is little better than the non-GM hybrids. The results help to explain why there is so much confusion arising from GM cotton release in India.

Insecticidal Activity of a Cry1Ca toxin of Bacillus thuringiensis Berliner (Firmicutes: Bacillaceae) and Its Synergism with the Cyt1Aa Toxin Against Aedes aegypti (Diptera: Culicidae)

2020 ◽  
Vol 57 (6) ◽  
pp. 1852-1856
Author(s):  
Sebastian E González-Villarreal ◽  
Mónica García-Montelongo ◽  
Jorge E Ibarra
Keyword(s):  
Bacillus Thuringiensis ◽  
Aedes Aegypti ◽  
Synergistic Effect ◽  
Joint Action ◽  
Recombinant Strain ◽  
Crystal Morphology ◽  
Graphical Method ◽  
Toxic Activity ◽  
Lepidopteran Species ◽  
Gene Coding

Abstract The Cry1C protein family of Bacillus thuringiensis form bipyramidal crystals, which are commonly associated with toxic activity against lepidopteran species; however, some members of this family may also be toxic to dipterans. In the present work, the Cry1Ca16 protein, synthesized by the B. thuringiensis LBIT-1217 strain, was analyzed. The gene coding for this protein was amplified, sequenced, and cloned into the pSTAB vector, which was electro-transferred into the acrystalliferous B. thuringiensis 4Q7 strain. The recombinant strain showed the expected bipyramidal crystal morphology, identical to the original LBIT-1217 strain and exhibited toxicity against larvae of Aedes aegypti (Diptera). Pure crystals from the recombinant strain were used in bioassays against Ae. aegypti larvae, estimating an LC50 of 4.61 μg/ml. Further studies on Cry1Ca16 mosquitocidal potential included joint-action tests with the Cyt1Aa protein crystals from B. thuringiensis israelensis. An LC50 using pure Cyt1Aa crystals was estimated at 0.73 μg/ml, whereas an LC50 of 0.61 μg/ml was estimated when both toxins were tested together. Data from these bioassays was analyzed using joint-action tests such as the Tammes-Bakuniak graphical method and the formula proposed by Tabashnik (1992). Both tests clearly showed a synergistic effect between these two toxins.

scholarly journals Effects of Bacillus thuringiensis HC-2 Combined with Biochar on the Growth and Cd and Pb Accumulation of Radish in a Heavy Metal-Contaminated Farmland under Field Conditions

2019 ◽  
Vol 16 (19) ◽  
pp. 3676 ◽  
Author(s):  
Zigang Li ◽  
Peng Wang ◽  
Xiaoyu Yue ◽  
Jingtao Wang ◽  
Baozeng Ren ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Bacillus Thuringiensis ◽  
Organic Matter Content ◽  
Dry Weight ◽  
Underlying Mechanism ◽  
Water Soluble ◽  
Field Conditions ◽  
Resistant Bacteria ◽  
Culture Solution ◽  
Rhizosphere Soils

The objective of this study was to explore the effect of heavy metal-resistant bacteria and biochar (BC) on reducing heavy metal accumulation in vegetables and the underlying mechanism. We tested Bacillus thuringiensis HC-2, BC, and BC+HC-2 for their ability to immobilize Cd and Pb in culture solution. We also studied the effects of these treatments on the dry weight and Cd and Pb uptake of radish in metal-contaminated soils under field conditions and the underlying mechanism. Treatment with HC-2, BC, and BC+HC-2 significantly reduced the water-soluble Cd (34–56%) and Pb (31–54%) concentrations and increased the pH and NH4+ concentration in solution compared with their vales in a control. These treatments significantly increased the dry weight of radish roots (18.4–22.8%) and leaves (37.8–39.9%) and decreased Cd (28–94%) and Pb (22–63%) content in the radish roots compared with the control. Treatment with HC-2, BC, and BC+HC-2 also significantly increased the pH, organic matter content, NH4+ content, and NH4+/NO3− ratio of rhizosphere soils, and decreased the DTPA-extractable Cd (37–58%) and Pb (26–42%) contents in rhizosphere soils of radish. Furthermore, BC+HC-2 had higher ability than the other two treatments to protect radish against Cd and Pb toxicity and increased radish biomass. Therefore, Bacillus thuringiensis HC-2 combined with biochar can ensure vegetable safety in situ for the bioremediation of heavy metal-polluted farmland.

scholarly journals Common Receptor for Bacillus thuringiensis Toxins Cry1Ac, Cry1Fa, and Cry1Ja in Helicoverpa armigera, Helicoverpa zea, and Spodoptera exigua

2005 ◽  
Vol 71 (9) ◽  
pp. 5627-5629 ◽  
Author(s):  
Carmen Sara Hernández ◽  
Juan Ferré
Keyword(s):  
Bacillus Thuringiensis ◽  
Helicoverpa Armigera ◽  
Helicoverpa Zea ◽  
Spodoptera Exigua ◽  
Cross Resistance ◽  
Binding Studies ◽  
Lepidopteran Species ◽  
Common Receptor ◽  
Binding Data ◽  
Helicoverpa Armígera

ABSTRACT Binding studies using 125I-Cry1Ac and biotinylated Cry1Fa toxins indicate the occurrence of a common receptor for Cry1Ac, Cry1Fa, and Cry1Ja in Helicoverpa armigera, Helicoverpa zea, and Spodoptera exigua. Our results, along with previous binding data and the observed cases of cross-resistance, suggest that this pattern seems to be widespread among lepidopteran species.

FIELD EVALUATION OF INSECTICIDES FOR THE CONTROL OF THE EUROPEAN SKIPPER, THYMELICUS LINEOLA (LEPIDOPTERA: HESPERIIDAE), IN QUEBEC

1979 ◽  
Vol 111 (12) ◽  
pp. 1313-1317 ◽  
Author(s):  
Michel Letendre ◽  
Jeremy N. McNeil
Keyword(s):  
Bacillus Thuringiensis ◽  
Larval Mortality ◽  
Field Evaluation ◽  
Field Conditions ◽  
Target Effects

AbstractThe efficacy of seven chemical insecticides, five commercial preparations of Bacillus thuringiensis, and two preparations containing diatom dust were tested against the European skipper, Thymelicus lineola (Ochs.), under field conditions. Satisfactory control was obtained with carbaryl, carbofuran, methomyl, permethrin, trichlorfon, Dipel 45B(=Dipel SC), Dipel WP, Thuricide 26B, Thuricide HPC, and Novabac 3 while dimethoate, chlorpyrifos, and the diatom dusts afforded little or no foliage protection. While larval mortality occurred less rapidly when B. thuringiensis preparations were applied, their use is strongly recommended as they afford the same degree of foliage protection as chemical insecticides and diminish possible undesirable off-target effects.

Litterbag decomposition of residues from Bacillus thuringiensis (Bt) rice hybrids and the parental lines under multiple field conditions

2014 ◽  
Vol 14 (10) ◽  
pp. 1669-1682 ◽  
Author(s):  
Manqiu Xiao ◽  
Changming Fang ◽  
Shanshan Dong ◽  
Xu Tang ◽  
Yi Chen ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Field Conditions ◽  
Bt Rice ◽  
Parental Lines ◽  
Multiple Field

scholarly journals Insecticidal Activity of Bacillus thuringiensis Strains on the Nettle Caterpillar, Euprosterna elaeasa (Lepidoptera: Limacodidae)

Insects ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 310
Author(s):  
Angelica Plata-Rueda ◽  
Hughes Antonio Quintero ◽  
José Eduardo Serrão ◽  
Luis Carlos Martínez
Keyword(s):  
Bacillus Thuringiensis ◽  
Pest Management ◽  
Insecticidal Activity ◽  
Oil Palm ◽  
Field Conditions ◽  
Organophosphate Insecticide ◽  
Lethal Effects ◽  
Potential Applications ◽  
Management Schemes ◽  
Nettle Caterpillar

In the present work, we evaluated the insecticidal activity of Bacillus thuringiensis (Bt) strains on Euprosterna elaeasa as an alternative for the organophosphate insecticide use in oil palm plantations in the Americas. The toxic effects of four Bt-strains (HD-1 var. kurstaki, SA-12 var. kurstaki, ABTS-1857 var. aizawai, and GC-91 var. aizawai) were evaluated against E. elaeasa caterpillars for toxicity, survival, anti-feeding, and mortality in field-controlled conditions. The Bt-strains, ABTS-1857 var. aizawai (LC50 = 0.84 mg mL−1), GC-91 var. aizawai (LC50 = 1.13 mg mL−1), and HD-1 var. kurstaki (LC50 = 1.25 mg mL−1), were the most toxic to E. elaeasa. The caterpillar survival was 99% without exposure to Bt-strains, and decreased to 52–23% in insects treated with the LC50 and 10–1% in insects exposed to LC90 after 48 h. Furthermore, Bt-strains decreased significantly the consumption of oil palm leaves of E. elaeasa 3 h after exposure. Mortality of E. elaeasa caterpillars caused by Bt-strains had similar lethal effects in the laboratory and in field conditions. Our data suggest that Bt-strains have insecticidal activity against E. elaeasa and, therefore, have potential applications in oil palm pest management schemes.

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