Occurrence and Molecular Characterization of Acetolactate Synthase (ALS) Inhibitor–Resistant Kochia (Kochia scoparia) in Western Canada

2011 ◽  
Vol 25 (1) ◽  
pp. 170-175 ◽  
Author(s):  
Hugh J. Beckie ◽  
Suzanne I. Warwick ◽  
Connie A. Sauder ◽  
Chris Lozinski ◽  
Scott Shirriff
Keyword(s):  
Molecular Characterization ◽  
Sequence Data ◽  
Acetolactate Synthase ◽  
Western Canada ◽  
Kochia Scoparia ◽  
Mean Frequency ◽  
Auxin Resistance ◽  
The Mean ◽  
Als Inhibitor

A survey of 109 fields was conducted across western Canada in spring 2007 to determine the extent of ALS-inhibitor and dicamba (synthetic auxin) resistance in kochia. Weed seedlings were collected from fields in three provinces of western Canada and transplanted into the greenhouse. Seeds were harvested from selfed plants, and the F1progeny were screened for resistance to the ALS-inhibitor mixture thifensulfuron–tribenuron or dicamba. All kochia populations were susceptible to dicamba. ALS inhibitor–resistant kochia was found in 85% of the fields surveyed in western Canada: 80 of 95 fields in Alberta, six of seven fields in Saskatchewan, and all seven fields in Manitoba. For the 93 ALS inhibitor–resistant populations, the mean frequency (±SE) of parental plants classified as resistant was 61 ± 3%. Most of the resistant populations (87%) were heterogeneous and contained both resistant and susceptible individuals.ALSsequence data (Pro197and Asp376mutations) and genotyping data (Trp574mutation) obtained for 87 kochia parental (i.e., field-collected) plants confirmed the presence of all three target-site mutations as well as two mutational combinations (Pro197+ Trp574, Asp376+ Trp574) in resistant individuals.

Response of glyphosate-resistant kochia (Kochia scoparia L. Schrad.) to alternative herbicides

2014 ◽  
Vol 94 (8) ◽  
pp. 1407-1411 ◽  
Author(s):  
Nikki Burton ◽  
Scott W. Shirriff ◽  
Hugh J. Beckie
Keyword(s):  
Acetolactate Synthase ◽  
Shoot Biomass ◽  
Western Canada ◽  
Weed Species ◽  
Kochia Scoparia ◽  
Oilseed Crops ◽  
Greenhouse Study ◽  
Herbicide Treatments ◽  
Chemical Fallow ◽  
Als Inhibitor

Burton, N., Shirriff, S. W. and Beckie, H. J. 2014. Response of glyphosate-resistant kochia (Kochia scoparia L. Schrad.) to alternative herbicides. Can. J. Plant Sci. 94: 1407–1411. A greenhouse study was conducted to examine the response of glyphosate-resistant (GR) plus acetolactate synthase (ALS) inhibitor-resistant kochia to five post-emergence herbicide treatments commonly used to control the weed species in chemical fallow, cereals, or oilseed crops in western Canada. The treatments, which were applied to two GR kochia biotypes and one non-GR (susceptible) biotype, included the labeled rate of dicamba, dicamba/fluroxypyr, dicamba/diflufenzopyr, MCPA/bromoxynil, and glufosinate. Both GR and non-GR biotypes responded similarly to each of the herbicide treatments. Although both GR biotypes were sensitive to the herbicides, MCPA/bromoxynil was the most effective treatment in reducing shoot biomass 3 wk after application (99%), followed by glufosinate (91%) then the dicamba mixtures (82%). Dicamba alone only suppressed kochia biomass (76% reduction).

Pollen- and Seed-Mediated Gene Flow in Kochia (Kochia scoparia)

Weed Science ◽  
2016 ◽  
Vol 64 (4) ◽  
pp. 624-633 ◽  
Author(s):  
Hugh J. Beckie ◽  
Robert E. Blackshaw ◽  
Linda M. Hall ◽  
Eric N. Johnson
Keyword(s):  
Gene Flow ◽  
Acetolactate Synthase ◽  
Western Canada ◽  
Kochia Scoparia ◽  
Hub And Spoke ◽  
Herbicide Resistant ◽  
Prevailing Wind Direction ◽  
Seed Mediated ◽  
Als Inhibitor ◽  
Natural Dispersal

Efficient natural dispersal of herbicide-resistance alleles via seed and pollen can markedly accelerate the incidence of herbicide-resistant weed populations across an agroecoregion. Studies were conducted in western Canada in 2014 and 2015 to investigate pollen- and seed-mediated gene flow in kochia. Pollen-mediated gene flow (PMGF) from glyphosate-resistant (GR) to non-GR kochia was quantified in a field trial (hub and spoke design) at Saskatoon, Saskatchewan. Seed-mediated gene flow of acetolactate synthase (ALS) inhibitor-resistant kochia as a function of tumbleweed speed and distance was estimated in cereal stubble fields at Lethbridge, Alberta and Scott, Saskatchewan. Regression analysis indicated that outcrossing from GR to adjacent non-GR kochia ranged from 5.3 to 7.5%, declining exponentially to 0.1 to 0.4% at 96 m distance. However, PMGF was significantly influenced by prevailing wind direction during pollination (maximum of 11 to 17% outcrossing down-wind). Seed dropped by tumbleweeds varied with distance and plant speed, approaching 90% or more (ca. 100,000 seeds or more) at distances of up to 1,000 m and plant speeds of up to 300 cm s–1. This study highlights the efficient proximal (pollen) and distal (seed) gene movement of this important GR weed.

Prevalence and Molecular Characterization of Microbial Contaminants in Raw Cow Milk of Tangail District in Bangladesh

2021 ◽  
Vol 17 ◽  
Author(s):  
Shahin Mahmud ◽  
Md. Firoz Ali ◽  
Md. Omar Faruque ◽  
Muhammad Wasim ◽  
Fatematuz Zuhura Evamoni ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Raw Milk ◽  
Health Impact ◽  
Cow Milk ◽  
Milk Consumption ◽  
Salmonella Spp ◽  
Mean Values ◽  
The Mean ◽  
Quality Of Milk

Objectives: The aim of this study is to evaluate the microbial quality and associated health Methodology: An intensive study was carried out from January¬ to October 2019 at the Tangail district of Bangladesh to assess bacterial contamination of raw milk. A total of 60 samples were examined by following the standard bacteriological methods and the health impact was evaluated with the help of a semi-structured-based questionnaire. Molecular characterization of isolated bacteria was carried out by PCR. Results: Results revealed the mean values of TVC and TCC in raw milk, udder, oil, and utensil samples were 7.6×106, 8.8×106, 4.6×106, and 1.3×106 cfu/ml and 3.7×105, 1.4×106, 4.4×105, and 8.9×104 cfu/ml, respectively. The yeast and mold in raw milk, udder, and oil were 1.5×103, 1.8×103, and 1.3×102cfu/ml, respectively, and the mean values of E. coli in the above-mentioned samples were 1.9×103, 1.8×104, 2.1×103, and 1.6×103cfu/ml, respectively. On the other hand, the mean values of Salmonella spp. in raw milk, udder, oil, and utensil samples were 2.4×102, 7.9×102, 1.5×102, and 1.1×102cfu/ml, respectively. Some selected isolates confirmed by molecular identification were tested for their sensitivity against some common antibiotics used in Bangladesh. Escherichia coli showed 70% resistance to Amoxicillin and 90% sensitivity to Ciprofloxacin whereas Salmonella spp. And Staphylococcus aureus showed 90% resistance to Ampicillin and both were 80% and 90% sensitive to Ciprofloxacin, respectively. Conclusion, Significance, and Impact of Study: Milk producers should be appropriately trained to monitor the overall hygienic conditions surrounding the production and handling of milk until it reaches the consumer. Frequent monitoring of the milk production facility, occasional testing of raw milk, and minimal use of antibiotics will ensure the quality of milk. Consumption of quality milk and avoidance of raw milk consumption will reduce the health risk of the consumers.

scholarly journals Neurophysiological Characterization of Thalamic Nuclei in Epileptic Anaesthetized Patients

2019 ◽  
Vol 9 (11) ◽  
pp. 312 ◽  
Author(s):  
Vega-Zelaya ◽  
Torres ◽  
Navas ◽  
Pastor
Keyword(s):  
General Anesthesia ◽  
Interspike Interval ◽  
The Other ◽  
Electrode Placement ◽  
Thalamic Nuclei ◽  
Mean Frequency ◽  
The Mean ◽  
Tonic Pattern ◽  
Deep Brain

Deep brain stimulation (DBS) requires precise localization, which is especially difficult at the thalamus, and even more difficult in anesthetized patients. We aimed to characterize the neurophysiological properties of the ventral intermediate (V.im), ventral caudal (V.c), and centromedian parvo (Ce.pc) and the magnocellular (Ce.mc) thalamic nuclei. We obtained microelectrode recordings from five patients with refractory epilepsy under general anesthesia. Somatosensory evoked potentials recorded by microelectrodes were used to identify the V.c nucleus. Trajectories were reconstructed off-line to identify the nucleus recorded, and the amplitude of the action potential (AP) and the tonic (i.e., mean frequency, density, probability of interspike interval) and phasic (i.e., burst index, pause index, and pause ratio) properties of the pattern discharges were analyzed. The Mahalanobis metric was used to evaluate the similarity of the patterns. The mean AP amplitude was higher for the V.im nucleus (172.7 ± 7.6 µV) than for the other nuclei, and the mean frequency was lower for the Ce.pc nucleus (7.2 ± 0.8 Hz) and higher for the V.c nucleus (11.9 ± 0.8 Hz) than for the other nuclei. The phasic properties showed a bursting pattern for the V.c nucleus and a tonic pattern for the centromedian and V.im nuclei. The Mahalanobis distance was the shortest for the V.im/V.c and Ce.mp/Ce.pc pairs. Therefore, the different properties of the thalamic nuclei, even for patients under general anesthesia, can be used to positively define the recorded structure, improving the exactness of electrode placement in DBS.

scholarly journals Ampelographic and molecular diversity among grapevine (Vitis spp.) cultivars

2009 ◽  
Vol 45 (No. 4) ◽  
pp. 160-168 ◽  
Author(s):  
A. Sabir ◽  
S. Tangolar ◽  
S. Buyukalaca ◽  
S. Kafkas
Keyword(s):  
Molecular Characterization ◽  
Molecular Diversity ◽  
Genetic Distances ◽  
Mean Values ◽  
Issr Analysis ◽  
Geographic Origins ◽  
The Mean ◽  
Vitis Spp

This study presents the ampelographic and molecular characterization of 44 grapevine cultivars. Ampelographic data were obtained during two vegetation periods using the latest version of the descriptors. Based on the mean values transformed by the method indicated in IBPGR publications, a dendrogram was constructed. ISSR analysis was also employed to characterize the genotypes at the DNA level. Twenty primers, selected on the basis of their discriminating potential, generated a total of 157 bands, of which 140 were polymorphic. The dendrograms constructed by the two approaches were largely similar in both the clustering position and divergence of varietal groups. The least distance was observed between Yuvarlak Cekirdeksiz and Superior Seedless. The clustering position of cultivars throughout the dendrograms was basically related to the genetic distances and main uses, as well as to geographic origins.

Glyphosate- and Acetolactate Synthase Inhibitor–Resistant Kochia (Kochia scoparia) in Western Canada

Weed Science ◽  
2013 ◽  
Vol 61 (2) ◽  
pp. 310-318 ◽  
Author(s):  
Hugh J. Beckie ◽  
Robert E. Blackshaw ◽  
Ryan Low ◽  
Linda M. Hall ◽  
Connie A. Sauder ◽  
...  
Keyword(s):  
Dose Response ◽  
Best Management Practices ◽  
Management Practices ◽  
Acetolactate Synthase ◽  
Glyphosate Resistance ◽  
Western Canada ◽  
Wild Oat ◽  
Green Foxtail ◽  
Inhibitor Resistance ◽  
Als Inhibitor

In summer, 2011, we investigated suspected glyphosate-resistant (GR) kochia in three chem-fallow fields (designated F1, F2, F3, each farmed by a different grower) in southern Alberta. This study characterizes glyphosate resistance in those populations, based on data from dose–response experiments. In a greenhouse experiment, the three populations exhibited a resistance factor ranging from 4 to 6 based on shoot biomass response (GR50ratios), or 5 to 7 based on survival response (LD50ratios). Similar results were found in a field dose–response experiment at Lethbridge, AB, in spring 2012 using the F2 kochia population. In fall 2011, we surveyed 46 fields within a 20-km radius of the three chem-fallow fields for GR kochia. In the greenhouse, populations were screened with glyphosate at 900 g ae ha−1. Seven populations were confirmed as GR, the farthest site located about 13 km from the three originally confirmed populations. An additional GR population more than 100 km away was later confirmed. Populations were screened for acetolactate synthase (ALS)–inhibitor (thifensulfuron : tribenuron) and dicamba resistance in the greenhouse, with molecular characterization of ALS-inhibitor resistance in the F1, F2, and F3 populations. All GR populations were resistant to the ALS-inhibiting herbicide, but susceptible to dicamba. ALS-inhibitor resistance in kochia was conferred by Pro197, Asp376, or Trp574amino acid substitutions. Based upon a simple empirical model with a parameter for selection pressure, calculated from weed relative abundance and glyphosate efficacy, and a parameter for seedbank longevity, kochia, wild oat, and green foxtail were the top three weeds, respectively, predicted at risk of selection for glyphosate resistance in the semiarid Grassland region of the Canadian prairies; wild oat, green foxtail, and cleavers species were predicted at greatest risk in the subhumid Parkland region. This study confirms the first occurrence of a GR weed in western Canada. Future research on GR kochia will include monitoring, biology and ecology, fitness, mechanism of resistance, and best management practices.

Molecular Characterization of Genes Coding for Wild-Type and Sulfonylurea-Resistant Acetolactate Synthase in the Cyanobacterium Synechococcus PC C7942

1990 ◽  
Vol 45 (5) ◽  
pp. 538-543 ◽  
Author(s):  
D. Friedberg ◽  
J. Seijffers
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Molecular Characterization ◽  
Amino Acid Level ◽  
Acetolactate Synthase ◽  
Mutant Gene ◽  
Wild Type ◽  
E Coli

We present here the isolation and molecular characterization of acetolactate synthase (ALS) genes from the cyanobacterium Synechococcus PCC7942 which specify a sulfonylurea-sensitive enzyme and from the sulfonylurea-resistant mutant SM3/20, which specify resistance to sulfonylurea herbicides. The ALS gene was cloned and mapped by complementation of an Escherichia coli ilv auxotroph that requires branched-chain amino acids for growth and lacks ALS activity. The cyanobacterial gene is efficiently expressed in this heterologous host. The ALS gene codes for 612 amino acids and shows high sequence homology (46%) at the amino acid level with ALS III of E. coli and with the tobacco ALS. The resistant phenotype is a consequence of proline to serine substitution in residue 115 of the deduced amino acid sequence. Functional expression of the mutant gene in wild-type Synechococcus and in E. coli confirmed that this amino-acid substitution is responsible for the resistance. Yet the deduced amino-acid sequence as compared with othjer ALS proteins supports the notion that the amino-acid context of the substitution is important for the resistance.

Sign in / Sign up

Export Citation Format

Share Document