Monitoring of spirodiclofen susceptibility in field populations of European red mites, Panonychus ulmi (Koch) (Acari: Tetranychidae), and the cross-resistance pattern of a laboratory-selected strain

2011 ◽  
Vol 67 (10) ◽  
pp. 1285-1293 ◽  
Author(s):  
Tina Kramer ◽  
Ralf Nauen
Keyword(s):  
Panonychus Ulmi ◽  
Cross Resistance ◽  
Resistance Pattern ◽  
The Cross

Cross-resistance and Fitness Cost Analysis of Resistance to Thiamethoxam in Melon and Cotton Aphid (Hemiptera: Aphididae)

2020 ◽  
Vol 113 (4) ◽  
pp. 1946-1954 ◽  
Author(s):  
Huihui Zhang ◽  
Anqi Chen ◽  
Tisheng Shan ◽  
Wenyang Dong ◽  
Xueyan Shi ◽  
...  
Keyword(s):  
Juvenile Hormone ◽  
Resistant Strain ◽  
Fitness Cost ◽  
Relative Fitness ◽  
Cross Resistance ◽  
Resistance Pattern ◽  
Continuous Exposure ◽  
Cotton Aphid ◽  
Developmental Duration ◽  
The Cross

Abstract The melon/cotton aphid, Aphis gossypii Glover, is a notorious pest in many crops. The neonicotinoid insecticide thiamethoxam is widely used for A. gossypii control. To evaluate thiamethoxam resistance risk, a melon/cotton aphid strain with an extremely high level of resistance to thiamethoxam (>2,325.6-fold) was established after selection with thiamethoxam for 24 generations. Additionally, the cross-resistance pattern to other neonicotinoids and fitness were analyzed. The cross-resistance results showed the thiamethoxam-resistant strain had extremely high levels of cross-resistance against clothianidin (>311.7-fold) and nitenpyram (299.9-fold), high levels of cross-resistance against dinotefuran (142.3-fold) and acetamiprid (76.6-fold), and low cross-resistance against imidacloprid (9.3-fold). Compared with the life table of susceptible strain, the thiamethoxam-resistant strain had a relative fitness of 0.950, with significant decreases in oviposition days and fecundity and prolonged developmental duration. The molecular mechanism for fitness costs was studied by comparing the mRNA expression levels of juvenile hormone acid O-methyltransferase (JHAMT), juvenile hormone-binding protein (JHBP), juvenile hormone epoxide hydrolase (JHEH), ecdysone receptor (EcR), ultraspiracle protein (USP), and Vitellogenin (Vg) in the susceptible and thiamethoxam-resistant strains. Significant overexpression of JHEH and JHBP and downregulation of EcR and Vg expression were found in the thiamethoxam-resistant strain. These results indicate that A. gossypii has the potential to develop extremely high resistance to thiamethoxam after continuous exposure, with a considerable fitness cost and cross-resistance to other neonicotinoids.

Efficacy of some pyrethroids against a strain of the rabbit ear mite ( Psoroptes cuniculi  ): an unusual cross-resistance pattern

1997 ◽  
Vol 83 (2) ◽  
pp. 203-205 ◽  
Author(s):  
László Pap ◽  
Péter Sárközy ◽  
Róbert Farkas ◽  
Edit Bleicher ◽  
András Szegö
Keyword(s):  
Cross Resistance ◽  
Resistance Pattern ◽  
Psoroptes Cuniculi ◽  
Rabbit Ear

First report of molecular basis of resistance to imazethapyr in common lambsquarters (Chenopodium album)

Weed Science ◽  
2019 ◽  
pp. 1-6
Author(s):  
Zhaofeng Huang ◽  
Xinxin Zhou ◽  
Chaoxian Zhang ◽  
Cuilan Jiang ◽  
Hongjuan Huang ◽  
...  
Keyword(s):  
Herbicide Resistance ◽  
Chenopodium Album ◽  
Acetolactate Synthase ◽  
Amino Acid Position ◽  
Cross Resistance ◽  
Resistance Pattern ◽  
Susceptible Population ◽  
First Report ◽  
Common Lambsquarters

Abstract Common lambsquarters (Chenopodium album L.) is one of the most troublesome weeds in soybean [Glycine max (L.) Merr.] and corn (Zea mays L.) fields in northeast China. In 2017, a C. album population that survived imazethapyr at the recommended field rate was collected from a soybean field in Heilongjiang Province in China. Experiments were conducted to determine the basis of resistance to imazethapyr and investigate the herbicide-resistance pattern in C. album. Dose–response tests showed that the resistant population (R) displayed high resistance to imazethapyr (20-fold) compared with the susceptible population (S). An in vitro acetolactate synthase (ALS) activity assay indicated that the ALS of the R population was resistant to imazethapyr compared with the ALS of the S population. Sequence analysis of the ALS gene revealed that the GCA was replaced by ACA at amino acid position 122, which resulted in an alanine to threonine substitution (Ala-122-Thr) in the R population. The R population displayed cross-resistance to thifensulfuron-methyl and flumetsulam but susceptibility to bispyribac-sodium, flucarbazone, glyphosate, mesotrione, and fomesafen. These results confirmed that the basis of imazethapyr resistance in C. album was conferred by the Ala-122-Thr substitution in the ALS enzyme. This is the first report of the target-site basis of ALS-inhibiting herbicide resistance in C. album.

Detection and fitness of dicarboximide-resistant isolates of Alternaria alternata from Dendrobium officinale, a Chinese indigenous medicinal herb.

Plant Disease ◽  
2020 ◽  
Author(s):  
Weicheng Zhao ◽  
Chunxia Sun ◽  
Lingling Wei ◽  
Wenchan Chen ◽  
Bingran Wang ◽  
...  
Keyword(s):  
Alternaria Alternata ◽  
Mycelial Growth ◽  
Medicinal Herb ◽  
Dendrobium Officinale ◽  
Cross Resistance ◽  
Resistance Pattern ◽  
Amino Acid Sequence Alignment ◽  
Group I ◽  
Black Spots ◽  
Significant Difference

Black spots caused by Alternaria Alternata poses a sever threat to the industry of Dendrobium officinale, a Chinese indigenous medicinal herb. Dicarboximide fungicides (DCFs) are intensively used to control this disease for decades in China, and offering excellent efficacy. The resistance of phytopathogenic pathogens against DCFs are reportedly selected in fields; however, the DCF-resistance of A. alternata from D. officinale is not well understood. The low procymidone-resistant (ProLR) isolates of A. alternata were detected in the commercial orchards of D. officinale in China in 2018 and biochemically characterized in this study. The result showed that the low procymidone-resistant (ProLR) isolates were selected in the commercial orchards with the resistance frequency of 100 %, and no significant difference in mycelial growth, sporulation and virulence was observed among the ProLR and ProS isolates. A positive cross-resistance pattern was exhibited between procymidone and iprodione. Amino acid sequence alignment results of AaOS-1 from the tested isolates showed that all the ProLR genotypes could be categorized into two groups, including group I (mutations at AaOs-1) and group II (no mutation). On procymidone (5.0 μg/ml) treatment condition, the AaOs-1 expression levels increased in the ProS isolates ranged from 2.94~3.69 folds higher than those on procymidone-free condition, while the AaOs-1 expressions of the ProLR isolates were significantly lower than those in the ProS isolates on the same conditions. The data indicated that the mutations at AaOs-1 are involved in the DCF-resistance of A. alternata selected in the D. officinale orchards.

scholarly journals The cross-resistance patterns and biochemical characteristics of an imidacloprid-resistant strain of the cotton aphid

2015 ◽  
Vol 40 (2) ◽  
pp. 55-59 ◽  
Author(s):  
Xiaokun Chen ◽  
Xugen Shi ◽  
Hongyan Wang ◽  
Jie Wang ◽  
Kaiyun Wang ◽  
...  
Keyword(s):  
Resistant Strain ◽  
Cross Resistance ◽  
Cotton Aphid ◽  
Biochemical Characteristics ◽  
Resistance Patterns ◽  
The Cross

A Rare Ile-2041-Thr Mutation in the ACCase Gene Confers Resistance to ACCase-inhibiting Herbicides in Shortawn Foxtail (Alopecurus aequalis)

Weed Science ◽  
2017 ◽  
Vol 65 (2) ◽  
pp. 239-246 ◽  
Author(s):  
Wenlei Guo ◽  
Lele Zhang ◽  
Hengzhi Wang ◽  
Qi Li ◽  
Weitang Liu ◽  
...  
Keyword(s):  
Herbicide Resistance ◽  
Control Strategies ◽  
Cross Resistance ◽  
Resistance Pattern ◽  
Susceptible Population ◽  
Dcaps Marker ◽  
Heterozygous Plant ◽  
Repeated Use ◽  
Moderate Resistance ◽  
Whole Plants

Understanding the mechanism of herbicide resistance is fundamental for designing sustainable weed control strategies and exploiting herbicides rationally. Shortawn foxtail is a problem grass weed infesting several important crops in China. The repeated use of acetyl-CoA carboxylase (ACCase)-inhibiting herbicides has resulted in herbicide resistance in this weed. The ACCase gene of resistant individuals of a shortawn foxtail population (JSLS-1) has an Ile-2041-Thr mutation. F2 generation seeds, originated from the same heterozygous plant, were harvested, and two homozygous mutant (JSLS-1RR) and wild (JSLS-1SS) populations for the Ile-2041-Thr mutation were obtained. In whole plants, the JSLS-1RR population conferred high resistance to fenoxaprop and clodinafop, moderate resistance to haloxyfop, low resistance to pinoxaden, and no obvious resistance to clethodim and sethoxydim, compared with JSLS-1SS and a proven susceptible population (HNXY-1). A derived cleaved amplified polymorphic sequence (dCAPS) marker was developed to rapidly detect the rare Ile-2041-Thr mutation in the shortawn foxtail population. This is the first report of the cross-resistance pattern of Ile-2041-Thr mutation, and the robust dCAPS marker could quickly detect this mutation in shortawn foxtail.

scholarly journals Cross-Resistance of Pink Bollworm (Pectinophora gossypiella) to Bacillus thuringiensis Toxins

2000 ◽  
Vol 66 (10) ◽  
pp. 4582-4584 ◽  
Author(s):  
Bruce E. Tabashnik ◽  
Yong-Biao Liu ◽  
Ruud A. de Maagd ◽  
Timothy J. Dennehy
Keyword(s):  
Bacillus Thuringiensis ◽  
Pink Bollworm ◽  
Pectinophora Gossypiella ◽  
Cross Resistance ◽  
Mechanism Of Resistance ◽  
Narrow Spectrum ◽  
Target Sites ◽  
The Cross

ABSTRACT Two strains of pink bollworm (Pectinophora gossypiella) selected in the laboratory for resistance to Bacillus thuringiensis toxin Cry1Ac had substantial cross-resistance to Cry1Aa and Cry1Ab but not to Cry1Bb, Cry1Ca, Cry1Da, Cry1Ea, Cry1Ja, Cry2Aa, Cry9Ca, H04, or H205. The narrow spectrum of resistance and the cross-resistance to activated toxin Cry1Ab suggest that reduced binding of toxin to midgut target sites could be an important mechanism of resistance.

scholarly journals Disruption of a Cadherin Gene Associated with Resistance to Cry1Ac δ-Endotoxin of Bacillus thuringiensis in Helicoverpa armigera

2005 ◽  
Vol 71 (2) ◽  
pp. 948-954 ◽  
Author(s):  
Xinjun Xu ◽  
Liangying Yu ◽  
Yidong Wu
Keyword(s):  
Bacillus Thuringiensis ◽  
Helicoverpa Armigera ◽  
Stop Codon ◽  
Premature Stop Codon ◽  
Recessive Gene ◽  
Laboratory Strain ◽  
Cross Resistance ◽  
Resistance Pattern ◽  
Bt Cotton ◽  
Helicoverpa Armígera

ABSTRACT A laboratory strain (GY) of Helicoverpa armigera (Hübner) was established from surviving larvae collected from transgenic cotton expressing a Bacillus thuringiensis var. kurstaki insecticidal protein (Bt cotton) in Gaoyang County, Hebei Province, People's Republic of China, in 2001. The GYBT strain was derived from the GY strain through 28 generations of selection with activated Cry1Ac delivered by diet surface contamination. When resistance to Cry1Ac in the GYBT strain increased to 564-fold after selection, we detected high levels of cross-resistance to Cry1Aa (103-fold) and Cry1Ab (>46-fold) in the GYBT strain with reference to those in the GY strain. The GYBT strain had a low level of cross-resistance to B. thuringiensis var. kurstaki formulation (Btk) (5-fold) and no cross-resistance to Cry2Aa (1.4-fold). Genetic analysis showed that Cry1Ac resistance in the GYBT strain was controlled by one autosomal and incompletely recessive gene. The cross-resistance pattern and inheritance mode suggest that the Cry1Ac resistance in the GYBT strain of H. armigera belongs to “mode 1,” the most common type of lepidopteran resistance to B. thuringiensis toxins. A cadherin gene was cloned and sequenced from both the GY and GYBT strains. Disruption of the cadherin gene by a premature stop codon was associated with a high level of Cry1Ac resistance in H. armigera. Tight linkage between Cry1Ac resistance and the cadherin locus was observed in a backcross analysis. Together with previous evidence found with Heliothis virescens and Pectinophora gossypiella, our results confirmed that the cadherin gene is a preferred target for developing DNA-based monitoring of B. thuringiensis resistance in field populations of lepidopteran pests.

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