Distribution Differences in the EPSPS Gene in Chromosomes Between Glyphosate-Resistant and -Susceptible Goosegrass (Eleusine indica)

Weed Science ◽  
2019 ◽  
pp. 1-28
Author(s):  
Jingchao Chen ◽  
Hailan Cui ◽  
Xiaoyan Ma ◽  
Yan Ma ◽  
Xiangju Li
Keyword(s):  
Resistance Index ◽  
Cotton Field ◽  
Metaphase Chromosomes ◽  
Susceptible Population ◽  
Homologous Chromosomes ◽  
Eleusine Indica ◽  
Epsps Gene ◽  
Copy Numbers ◽  
Resistant Individual ◽  
Cotton Fields

Abstract Glyphosate is a popular herbicide used to control goosegrass [Eleusine indica (L.) Gaertn.], one of the most troublesome weeds in cotton fields. However, high selection pressure has led to some populations being difficult to control in cotton fields in China. In this study, levels of glyphosate resistance were quantified and 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) amplification was confirmed. In addition, distribution of the EPSPS gene among the chromosomes was also investigated using fluorescence in situ hybridization (FISH) methodology. One population (AHCZ) was confirmed to be glyphosate resistant with a resistance index of 3.4 and significantly reduced shikimate accumulation compared to susceptible population. All examined individuals exhibited no mutations in the EPSPS gene in AHCZ. Expression and copy numbers of EPSPS in the AHCZ population were 5.7 and 15.4 times higher, respectively, than in the susceptible population. A positive correlation was identified between signal intensities of primary anti-EPSPS antibody and copy numbers of the EPSPS protein, as indicated by immunoblot analysis. FISH results revealed that, in mitotic metaphase chromosomes, signals were observed dispersed across two sets of homologous chromosomes in a resistant individual (copy number = 31), while in susceptible individuals, signals were only partially detected in one set of homologous chromosomes. In interphase nuclei, EPSPS signals were brightest in resistant individual compared to those that were susceptible. In conclusion, one E. indica population from a cotton field in the Anhui Province has evolved resistance to glyphosate, and EPSPS gene amplification was confirmed as the resistant mechanism.

scholarly journals Repetitive DNA sequences accelerate molecular cytogenetic research in plants with small chromosomes

2019 ◽  
Vol 24 (2) ◽  
pp. 82
Author(s):  
Agus Budi Setiawan ◽  
Ari Wibowo ◽  
Chee How Teo ◽  
Shinji Kikuchi ◽  
Takato Koba
Keyword(s):  
Repetitive Dna ◽  
Dna Sequences ◽  
5S Rdna ◽  
Repetitive Dna Sequences ◽  
Type I ◽  
Chromosome Identification ◽  
Metaphase Chromosomes ◽  
Homologous Chromosomes ◽  
Centromeric Sequence ◽  
Subtelomeric Sequence

Repetitive DNA sequences are highly abundant in plant genomes and are favorable probes for chromosome identification in plants. However, it is difficult to conduct studies on the details of metaphase chromosome structures in plants with small chromosomes due to their highly condensed status. Therefore, identification of homologous chromosomes for karyotyping and analyzing chromosome structures is a challenging issue for cytogeneticists without specific probes and precise chromosome stages. In this study, five repetitive DNA probes, i.e., 5S and 45S ribosomal DNAs (rDNAs), melon centromeric sequence (Cmcent), cucumber subtelomeric sequence (Type I), and microsatellite (CT)10 repeats, were used to identify primary constrictions and homologous chromosomes for karyotyping. Four and two loci of 45S rDNA were respectively observed on metaphase and pachytene chromosomes of Abelia × grandiflora. Cmcent was detected on both primary constrictions of melon pachytene and metaphase chromosomes. Furthermore, one pair of 5S rDNA signals were hybridized on melon metaphase chromosomes. Eight and two loci of 45S and 5S rDNA were respectively detected on cucumber chromosomes. Type I and (CT)10 probes were specifically hybridized on subtelomeric and interstitial regions on the chromosomes, respectively. These results suggest that repetitive DNA sequences are versatile probes for chromosome identification in plants with small chromosomes, particularly for karyotyping analyses.

Confirmation and characterization of cyhalofop-butyl–resistant Chinese sprangletop (Leptochloa chinensis) populations from China

Weed Science ◽  
2020 ◽  
Vol 68 (3) ◽  
pp. 253-259
Author(s):  
Yajun Peng ◽  
Lang Pan ◽  
Ducai Liu ◽  
Xiaomei Cheng ◽  
Guolan Ma ◽  
...  
Keyword(s):  
Resistance Index ◽  
Resistance Mechanisms ◽  
The Other ◽  
Susceptible Population ◽  
Acetyl Coenzyme A ◽  
Target Site Resistance ◽  
High Level ◽  
Acetyl Coenzyme A Carboxylase ◽  
Grass Weed

AbstractChinese sprangletop [Leptochloa chinensis (L.) Nees] is one grass weed severely affecting rice (Oryza sativa L.) growth in paddies in China. Cyhalofop-butyl is the main herbicide used to control grass weeds in Chinese paddy fields, especially for controlling L. chinensis; however, L. chinensis has evolved resistance to cyhalofop-butyl due to continuous and extensive application. To investigate cyhalofop-butyl resistance levels and mechanisms in L. chinensis in some of the Chinese rice areas, 66 field populations were collected and treated with cyhalofop-butyl. Of these tested populations, 10 showed a high level of resistance to cyhalofop-butyl; the 50% effective dose ranged within 108.4 to 1,443.5 g ai ha−1 with resistance index values of 9.1 to 121.8 when compared with the susceptible population. Acetyl-coenzyme A carboxylase genes (ACCase) of susceptible and all 10 resistant populations were amplified and sequenced. Among them, Ile-1781-Leu, Trp-2027-Cys, Trp-2027-Ser, and Ile-2041-Asn mutations were found in five resistant populations. No known resistance-related mutations were found in the other five resistant populations, indicating that resistance to cyhalofop-butyl in these populations was likely to be endowed by non–target site resistance mechanisms. Notably, the Ile-1781-Leu and Trp-2027-Cys substitutions have previously been reported, but this is the first report of Trp-2027-Ser and Ile-2041-Asn mutations in L. chinensis. Furthermore, three derived cleaved amplified polymorphic sequence methods were developed to rapidly detect these mutations in L. chinensis.

scholarly journals First Report of Glyphosate-Resistant Biotype of Eleusine Indica (L.) Gaertn. in Europe

Agronomy ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1692
Author(s):  
Donato Loddo ◽  
Gaetano Imperatore ◽  
Andrea Milani ◽  
Silvia Panozzo ◽  
Silvia Farinati ◽  
...  
Keyword(s):  
Weight Reduction ◽  
Southern Italy ◽  
Resistance Index ◽  
Resistance Mechanisms ◽  
Fresh Weight ◽  
Eleusine Indica ◽  
Dna Analyses ◽  
Plant Nursery ◽  
Resistant Population ◽  
Target Site Resistance

Glyphosate-resistant biotypes of Eleusine indica (L.) Gaertn. have been detected in Asia, the Americas but not in Europe. The aim of this study was to evaluate resistance levels and possible target site resistance mechanisms of an E. indica biotype (19-1) collected from a plant nursery in Southern Italy where poor glyphosate efficacy was reported. Two dose-response experiments were conducted to evaluate the sensitivity of biotype 19-1 to glyphosate in comparison with two susceptible checks. 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) sequencing was performed to identify possible mutations conferring the resistance. The susceptible biotypes were completely controlled at the glyphosate recommended field dose of 360 g ae ha−1, while 50% of the plants of biotype 19-1 survived at 1440 g ae ha−1. The resistance index of biotype 19-1 ranged between 5.8 and 7.3 for the response variables of fresh weight reduction and plant survival, respectively. All the plants surviving glyphosate application and sampled for DNA analyses had the point mutation P106A. The biotype 19-1 can be confirmed as glyphosate-resistant, representing the first glyphosate-resistant population of E. indica in Europe.

scholarly journals The Triple Amino Acid Substitution TAP-IVS in the EPSPS Gene Confers High Glyphosate Resistance to the Superweed Amaranthus hybridus

2019 ◽  
Vol 20 (10) ◽  
pp. 2396 ◽  
Author(s):  
Maria J. García ◽  
Candelario Palma-Bautista ◽  
Antonia M. Rojano-Delgado ◽  
Enzo Bracamonte ◽  
João Portugal ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Substitution ◽  
Glyphosate Resistance ◽  
Wild Type ◽  
Triple Mutant ◽  
Resistance Level ◽  
Amaranthus Hybridus ◽  
Susceptible Population ◽  
Epsps Gene ◽  
Wide Range

The introduction of glyphosate-resistant (GR) crops revolutionized weed management; however, the improper use of this technology has selected for a wide range of weeds resistant to glyphosate, referred to as superweeds. We characterized the high glyphosate resistance level of an Amaranthus hybridus population (GRH)—a superweed collected in a GR-soybean field from Cordoba, Argentina—as well as the resistance mechanisms that govern it in comparison to a susceptible population (GSH). The GRH population was 100.6 times more resistant than the GSH population. Reduced absorption and metabolism of glyphosate, as well as gene duplication of 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) or its overexpression did not contribute to this resistance. However, GSH plants translocated at least 10% more 14C-glyphosate to the rest of the plant and roots than GRH plants at 9 h after treatment. In addition, a novel triple amino acid substitution from TAP (wild type, GSH) to IVS (triple mutant, GRH) was identified in the EPSPS gene of the GRH. The nucleotide substitutions consisted of ATA102, GTC103 and TCA106 instead of ACA102, GCG103, and CCA106, respectively. The hydrogen bond distances between Gly-101 and Arg-105 positions increased from 2.89 Å (wild type) to 2.93 Å (triple-mutant) according to the EPSPS structural modeling. These results support that the high level of glyphosate resistance of the GRH A. hybridus population was mainly governed by the triple mutation TAP-IVS found of the EPSPS target site, but the impaired translocation of herbicide also contributed in this resistance.

scholarly journals Meiotic crossovers characterized by haplotype-specific chromosome painting in maize

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Lívia do Vale Martins ◽  
Fan Yu ◽  
Hainan Zhao ◽  
Tesia Dennison ◽  
Nick Lauter ◽  
...  
Keyword(s):  
Recombinant Inbred Lines ◽  
Critical Role ◽  
Fish Analysis ◽  
Recombinant Chromosome ◽  
Metaphase Chromosomes ◽  
Chromosome 10 ◽  
Homologous Chromosomes ◽  
Proximal Half ◽  
Maize Inbreds

Abstract Meiotic crossovers (COs) play a critical role in generating genetic variation and maintaining faithful segregation of homologous chromosomes during meiosis. We develop a haplotype-specific fluorescence in situ hybridization (FISH) technique that allows visualization of COs directly on metaphase chromosomes. Oligonucleotides (oligos) specific to chromosome 10 of maize inbreds B73 and Mo17, respectively, are synthesized and labeled as FISH probes. The parental and recombinant chromosome 10 in B73 x Mo17 F1 hybrids and F2 progenies can be unambiguously identified by haplotype-specific FISH. Analysis of 58 F2 plants reveals lack of COs in the entire proximal half of chromosome 10. However, we detect COs located in regions very close to the centromere in recombinant inbred lines from an intermated B73 x Mo17 population, suggesting effective accumulation of COs in recombination-suppressed chromosomal regions through intermating and the potential to generate favorable allelic combinations of genes residing in these regions.

scholarly journals Performance evaluation of Border irrigation method for cotton field

2018 ◽  
Vol 10 (1) ◽  
pp. 222-229
Author(s):  
Amandeep Singh ◽  
R. K. Jhorar ◽  
Sanjay Kumar ◽  
Narender Kumar
Keyword(s):  
Performance Evaluation ◽  
Water Distribution ◽  
Sandy Loam ◽  
Infiltration Rate ◽  
Cotton Field ◽  
Water Application ◽  
Canal Irrigation ◽  
Irrigation Method ◽  
Cotton Fields ◽  
Distribution Efficiency

Performance evaluation of Border irrigation method was carried out for cotton field in village Kirarkot, Sirsa (Haryana). Water application, storage and distribution efficiency were estimated using measurements of soil moisture (%), infiltration rate (cm/hr), water advance and recession time (minute) during different irrigation events. The advance time increased during the growing season due to increased infiltration rate and increased resistance to flow by the growing crops. The water application efficiency of cotton field was 100 per cent as average applied depth (8.26 cm for canal irrigation and 9.06 cm for tubewell irrigation) of irrigation was less than the average required depth (10.30 cm for canal irrigation and 10.98 cm for tubewell irrigation) throughout the field plots. The observed water storage efficiency in different cotton fields varied from 72.92 - 90.08 per cent indicating under irrigation. Water distribution efficiency of cotton fields (97.8 -99.2per cent) indicated a relatively high degree of uniformity of water application. Stratified soil profile (sandy loam: 0-30 cm and sandy clay loam: 30-120 cm) of the selected fields reduced the infiltration rate to relatively very low value after 10-15 minutes creating favourable condition for uniformity of water application under border irrigation.

scholarly journals THE PHYLOGENETIC RELATIONSHIPS OF THE MEMBERS OF THE DROSOPHILA ROBUSTA GROUP

Genetics ◽  
1973 ◽  
Vol 73 (2) ◽  
pp. 319-350
Author(s):  
Yamuna Narayanan
Keyword(s):  
Phylogenetic Relationships ◽  
Middle Miocene ◽  
Ganglion Cells ◽  
The United States ◽  
Metaphase Chromosomes ◽  
Land Bridge ◽  
X Chromosomes ◽  
Ancestral Species ◽  
Homologous Chromosomes ◽  
Drosophila Robusta

ABSTRACT The phylogenetic relationships among the species of the D. robusta group were investigated by the analysis of chromosomal differences. Six of the ten known members of the D. robusta group were available for the study: D. colorata and D. robusta from the United States, and D. sordidula,  D. pseudosordidula,  D. lacertosa, and D, moriwakii from Japan. Analysis of the metaphase chromosomes from larval ganglion cells suggests that D. moriwakii and D. colorata, with rod-shaped X-chromosomes, are the more ancestral species, while D. sordidula,  D. pseudosordidula,  D. robusta, and D. lacertosa, with Vshaped X-chromosomes, are derived. The ancestral position of D. colorata and D. moriwakii is further strengthened by the fact that these are the two species in the D. robusta group that are cytologically closest to D. nigromelanica of the related D. melanica group. Of the four derived species, D. sordidula was found to be the closest to the ancestral species. The phylogeny based on the analysis of the gene sequences in the homologous chromosomes agreed with that indicated by the metaphase chromosomes. Since all attempts to obtain hybrids were unsuccessful except for the cross involving D. moriwakii females and D. colorata males, photographic maps of the salivary chromosomes were used to determine homology between the chromosomes of the different species. Evidence is presented to indicate that the D. robusta group originated in Asia (Japan), and that there were two migrations to the New World, the first leading to D. robusta, and the second to D. colorata. It is suggested that the route of migrations was across the Bering Land Bridge, and further, that the migrations occurred during the period from late Oligocene to middle Miocene, 20-25 million years ago.

scholarly journals Monitoring Oasis Cotton Fields Expansion in Arid Zones Using the Google Earth Engine: A Case Study in the Ogan-Kucha River Oasis, Xinjiang, China

2022 ◽  
Vol 14 (1) ◽  
pp. 225
Author(s):  
Lijing Han ◽  
Jianli Ding ◽  
Jinjie Wang ◽  
Junyong Zhang ◽  
Boqiang Xie ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Drip Irrigation ◽  
Google Earth ◽  
Cotton Field ◽  
Arid Zones ◽  
Landsat 8 ◽  
Land Resource ◽  
Google Earth Engine ◽  
Cotton Fields ◽  
Sentinel 2

Rapid and accurate mapping of the spatial distribution of cotton fields is helpful to ensure safe production of cotton fields and the rationalization of land-resource planning. As cotton is an important economic pillar in Xinjiang, accurate and efficient mapping of cotton fields helps the implementation of rural revitalization strategy in Xinjiang region. In this paper, based on the Google Earth Engine cloud computing platform, we use a random forest machine-learning algorithm to classify Landsat 5 and 8 and Sentinel 2 satellite images to obtain the spatial distribution characteristics of cotton fields in 2011, 2015 and 2020 in the Ogan-Kucha River oasis, Xinjiang. Unlike previous studies, the mulching process was considered when using cotton field phenology information as a classification feature. The results show that both Landsat 5, Landsat 8 and Sentinel 2 satellites can successfully classify cotton field information when the mulching process is considered, but Sentinel 2 satellite classification results have the best user accuracy of 0.947. Sentinel 2 images can distinguish some cotton fields from roads well because they have higher spatial resolution than Landsat 8. After the cotton fields were mulched, there was a significant increase in spectral reflectance in the visible, red-edge and near-infrared bands, and a decrease in the short-wave infrared band. The increase in the area of oasis cotton fields and the extensive use of mulched drip-irrigation water saving facilities may lead to a decrease in the groundwater level. Overall, the use of mulch as a phenological feature for classification mapping is a good indicator in cotton-growing areas covered by mulch, and mulch drip irrigation may lead to a decrease in groundwater levels in oases in arid areas.

scholarly journals Meiotic effects of MSH4 copy number variation support an adaptive role for post-polyploidy gene loss

2018 ◽  
Author(s):  
Adrián Gonzalo ◽  
Marie-Odile Lucas ◽  
Catherine Marquis ◽  
Andrew Lloyd ◽  
Eric Jenczewski
Keyword(s):  
Chromosome Segregation ◽  
Meiotic Recombination ◽  
Copy Number ◽  
Gene Loss ◽  
Duplicate Gene ◽  
Single Copy ◽  
Homologous Chromosomes ◽  
Evolutionary Forces ◽  
Copy Numbers ◽  
Number Variation

ABSTRACTMany eukaryotes descend from polyploid ancestors that experienced massive duplicate gene loss. This genomic erosion is particularly strong for duplicated (meiotic) recombination genes that return to a single copy more rapidly than genome average following polyploidy. To better understand the evolutionary forces underlying duplicate loss, we analysed how varying copy numbers of MSH4, an essential meiotic recombination gene, influences crossover formation in allotetraploid Brassica napus. We show that faithful chromosome segregation and crossover frequencies between homologous chromosomes are unchanged with MSH4 duplicate loss; by contrast, crossovers between homoeologous chromosomes (which result in genomic rearrangements) decrease with reductions in MSH4 copy number. We also found that inter-homoeologue crossovers originate almost exclusively from the MSH4-dependent crossover pathway. Limiting the efficiency of this pathway by decreasing the copy number of key meiotic recombination genes could therefore contribute to adaptation to polyploidy, by promoting regular chromosome segregation and genomic stability.

scholarly journals Cluster analysis of karyotype similarity coefficients in Epimedium (Berberidaceae): insights in the systematics and evolution

PhytoKeys ◽  
2020 ◽  
Vol 161 ◽  
pp. 11-26
Author(s):  
Lin-Jiao Wang ◽  
Meng-Di Gao ◽  
Mao-Yin Sheng ◽  
Jie Yin
Keyword(s):  
Genetic Diversity ◽  
Cluster Analysis ◽  
Geographical Distribution ◽  
Karyotype Analysis ◽  
Resource Utilisation ◽  
Mitotic Metaphase ◽  
Interspecific Relationship ◽  
Similarity Coefficients ◽  
Metaphase Chromosomes ◽  
Homologous Chromosomes

In order to evaluate the genome evolution and systematics, karyotype analysis of mitotic metaphase chromosomes in 51 taxa of Epimedium and two species of Vancouveria was conducted. The 53 taxa were clustered, based on their karyotype similarity coefficients. Results showed that the 53 taxa studied were all diploid with 12 chromosomes (2n = 2x = 12). Each taxon had one pair of satellites located on pair I of homologous chromosomes. Moreover, the karyotype types of the 53 taxa studied were all type 1A or 2A of Stebbins. It can be concluded that the karyotypes between species are indeed very similar and the genome of Epimedium was conservative in evolution. The cluster analysis of karyotype similarity coefficients could provide valuable clues for the systematics and taxonomy of Epimedium. Results of the cluster analysis strongly supported the previous taxonomic division of E. subg. Rhizophyllum and E. subg. Epimedium. The results also showed that the interspecific relationship was closely correlated with geographical distribution in E. subg. Epimedium and the taxa native to east Asia had the highest genetic diversity in Epimedium. Finally, the origin of the modern geographical distribution of Epimedium was inferred. Results of the present study have significant scientific values in further studies on resource utilisation, taxonomy and phylogeny in Epimedium.

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