Current Understanding of the History, Global Spread, Ecology, Evolution, and Management of the Corn Bacterial Leaf Streak Pathogen, Xanthomonas vasicola pv. vasculorum

2020 ◽  
Vol 110 (6) ◽  
pp. 1124-1131
Author(s):  
Mary Ortiz-Castro ◽  
Terra Hartman ◽  
Teresa Coutinho ◽  
Jillian M. Lang ◽  
Kevin Korus ◽  
...  
Keyword(s):  
United States ◽  
South Africa ◽  
South America ◽  
The United States ◽  
Molecular Diagnostic ◽  
Diagnostic Tools ◽  
Bacterial Leaf Streak ◽  
Long Distance ◽  
North And South America ◽  
North And South

Bacterial leaf streak of corn, caused by Xanthomonas vasicola pv. vasculorum, has been present in South Africa for over 70 years, but is an emerging disease of corn in North and South America. The only scientific information pertaining to this disease on corn came from work done in South Africa, which primarily investigated host range on other African crops, such as sugarcane and banana. As a result, when the disease was first reported in the United States in 2016, there was very limited information on where this pathogen came from, how it infects its host, what plant tissue(s) it is capable of infecting, where initial inoculum comes from at the beginning of each crop season, how the bacterium spreads from plant to plant and long distance, what meteorological variables and agronomic practices favor disease development and spread, how many other plant species X. vasicola pv. vasculorum is capable of infecting or using as alternate hosts, and if the bacterium will be able to persist in all corn growing regions of the United States. There were also no rapid diagnostic assays available which initially hindered prompt identification prior to the development of molecular diagnostic tools. The goal of this synthesis is to review the history of X. vasicola pv. vasculorum and bacterial leaf streak in South Africa and its movement to North and South America, and highlight the recent research that has been done in response to the emergence of this bacterial disease.

Jujuyaspis borealis and associated trilobites and conodonts from the Lower Ordovician of Texas and Utah

1987 ◽  
Vol 61 (1) ◽  
pp. 112-121 ◽  
Author(s):  
James H. Stitt ◽  
James F. Miller
Keyword(s):  
United States ◽  
South America ◽  
North American ◽  
The United States ◽  
International Agreement ◽  
Lower Ordovician ◽  
Central Texas ◽  
North And South America ◽  
First Time ◽  
North And South

Jujuyaspis borealis is reported from earliest Ordovician (North American usage) limestones in central Texas and western Utah, the first time this species has been recognized in the United States. Jujuyaspis is a widespread olenid trilobite that occurs near the base of the Tremadoc Series in a variety of lithologies in North and South America, Europe, and Asia. When international agreement is reached on the exact horizon at or near the base of the Tremadoc Series that is to be used as the Cambrian–Ordovician boundary, Jujuyaspis will likely prove to be a very useful taxon for recognition of the boundary interval.

scholarly journals The concern of Andrey Sheptytsky, the Metropolitan bishop, about Ukrainian Emigrants in North and South America

1970 ◽  
Vol 23 ◽  
pp. 258-270
Author(s):  
Adam Kubasik
Keyword(s):  
United States ◽  
Twentieth Century ◽  
North America ◽  
South America ◽  
The United States ◽  
Immigrant Communities ◽  
Political Agitation ◽  
The Usa ◽  
North And South America ◽  
North And South

At the turn of the nineteenth and twentieth century a large group of Galician Ruthenians emigrated to North America and the United States and Canada, South America - mainly to Argentina and Brazil. Sheptytsky visited North America in 1910. He met with Ukrainian Greek Catholic immigrant communities in the United States and Canada. In 1921, he visited the USA and Canada again. In 1922 he arrived to Argentina and Brazil. He did not conduct open political agitation. However, some of his speeches have an anti-Polish character.

scholarly journals Genomic Acquisitions in Emerging Populations of Xanthomonas vasicola pv. vasculorum Infecting Corn in the United States and Argentina

2020 ◽  
Vol 110 (6) ◽  
pp. 1161-1173 ◽  
Author(s):  
Alvaro L. Perez-Quintero ◽  
Mary Ortiz-Castro ◽  
Jillian M. Lang ◽  
Adrien Rieux ◽  
Guangxi Wu ◽  
...  
Keyword(s):  
United States ◽  
South America ◽  
Phylogenetic Analyses ◽  
The United States ◽  
Virulence Determinants ◽  
Genetic Changes ◽  
Genomic Changes ◽  
Future Work ◽  
North And South America ◽  
North And South

Xanthomonas vasicola pv. vasculorum is an emerging bacterial plant pathogen that causes bacterial leaf streak on corn. First described in South Africa in 1949, reports of this pathogen have greatly increased in the past years in South America and in the United States. The rapid spread of this disease in North and South America may be due to more favorable environmental conditions, susceptible hosts and/or genomic changes that favored the spread. To understand whether genetic mechanisms exist behind the recent spread of X. vasicola pv. vasculorum, we used comparative genomics to identify gene acquisitions in X. vasicola pv. vasculorum genomes from the United States and Argentina. We sequenced 41 genomes of X. vasicola pv. vasculorum and the related sorghum-infecting X. vasicola pv. holcicola and performed comparative analyses against all available X. vasicola genomes. Time-measured phylogenetic analyses showed that X. vasicola pv. vasculorum strains from the United States and Argentina are closely related and arose from two introductions to North and South America. Gene content comparisons identified clusters of genes enriched in corn X. vasicola pv. vasculorum that showed evidence of horizontal transfer including one cluster corresponding to a prophage found in all X. vasicola pv. vasculorum strains from the United States and Argentina as well as in X. vasicola pv. holcicola strains. In this work, we explore the genomes of an emerging phytopathogen population as a first step toward identifying genetic changes associated with the emergence. The acquisitions identified may contain virulence determinants or other factors associated with the spread of X. vasicola pv. vasculorum in North and South America and will be the subject of future work.

scholarly journals Test of Martin’s overkill hypothesis using radiocarbon dates on extinct megafauna

2015 ◽  
Vol 113 (4) ◽  
pp. 886-891 ◽  
Author(s):  
Todd A. Surovell ◽  
Spencer R. Pelton ◽  
Richard Anderson-Sprecher ◽  
Adam D. Myers
Keyword(s):  
United States ◽  
South America ◽  
The United States ◽  
Small Population ◽  
Ecological Impacts ◽  
Radiocarbon Dates ◽  
Frequency Distributions ◽  
Human Colonization ◽  
North And South America ◽  
North And South

Following Martin [Martin PS (1973) Science 179:969–974], we propose the hypothesis that the timing of human arrival to the New World can be assessed by examining the ecological impacts of a small population of people on extinct Pleistocene megafauna. To that end, we compiled lists of direct radiocarbon dates on paleontological specimens of extinct genera from North and South America with the expectation that the initial decline of extinct megafauna should correspond in time with the initial evidence for human colonization and that those declines should occur first in eastern Beringia, next in the contiguous United States, and last in South America. Analyses of spacings and frequency distributions of radiocarbon dates for each region support the idea that the extinction event first commenced in Beringia, roughly 13,300–15,000 BP. For the United States and South America, extinctions commenced considerably later but were closely spaced in time. For the contiguous United States, extinction began at ca. 12,900–13,200 BP, and at ca. 12,600–13,900 BP in South America. For areas south of Beringia, these estimates correspond well with the first significant evidence for human presence and are consistent with the predictions of the overkill hypothesis.

scholarly journals A Multistate Comparison of Native Octoploid Strawberries from North and South America

2001 ◽  
Vol 126 (5) ◽  
pp. 579-586 ◽  
Author(s):  
J.F. Hancock ◽  
C.A. Finn ◽  
S.C. Hokanson ◽  
J.J. Luby ◽  
B.L. Goulart ◽  
...  
Keyword(s):  
United States ◽  
Disease Resistance ◽  
South America ◽  
Fruit Set ◽  
The United States ◽  
Fruit Color ◽  
Elite Group ◽  
North And South America ◽  
North And South ◽  
Location Interaction

An elite group of 38 strawberry accessions representing all subspecies of the beach strawberry [Fragaria chiloensis (L.) Miller] and the scarlet strawberry (F. virginiana Miller) was planted in a replicated design at five locations across the United States, and evaluated for plant vigor, flowering date, runner density, fruit set, fruit appearance, and foliar disease resistance. Considerable genotyp× location interaction was observed for many of these traits. However, a few genotypes were impressive at all locations including PI 551735 (FRA 368) with its unusually large, early fruit, and PIs 612486 (NC 95-19-1), 612493 (Frederick 9), and 612499 (RH 30), which were very vigorous and had unusually good fruit color. Genotypes that were superior at individual locations included PIs 551527 (FRA 110) and 551728 (Pigeon Pt.) in Maryland for their large fruit, and PI 612490 (Scotts Creek) in Oregon which had extremely large fruit, superior color, firmness, and flavor. The PIs 612495 (LH 50-4), 612498 (RH 23), and 612499 (RH 30) performed well as day neutrals at multiple sites.

scholarly journals Soybean Sudden Death Syndrome Species Diversity Within North and South America Revealed by Multilocus Genotyping

2010 ◽  
Vol 100 (1) ◽  
pp. 58-71 ◽  
Author(s):  
Kerry O'Donnell ◽  
Stacy Sink ◽  
María Mercedes Scandiani ◽  
Alicia Luque ◽  
Analía Colletto ◽  
...  
Keyword(s):  
Sudden Death ◽  
South America ◽  
Sudden Death Syndrome ◽  
Molecular Diagnostic ◽  
Sequence Analyses ◽  
Diagnostic Assays ◽  
Molecular Phylogenetic ◽  
Species Specific ◽  
North And South America ◽  
North And South

Sudden death syndrome (SDS) of soybean has become a serious constraint to the production of this crop in North and South America. Phenotypic and multilocus molecular phylogenetic analyses, as well as pathogenicity experiments, have demonstrated that four morphologically and phylogenetically distinct fusaria can induce soybean SDS. Published molecular diagnostic assays for the detection and identification of these pathogens have reported these pathogens as F. solani, F. solani f. sp. glycines, or F. solani f. sp. phaseoli, primarily because the species limits of these four pathogens were only recently resolved. In light of the recent discovery that soybean SDS and Phaseolus and mung bean root rot (BRR) are caused by four and two distinct species, respectively, multilocus DNA sequence analyses were conducted to assess whether any of the published molecular diagnostic assays were species-specific. Comparative DNA sequence analyses of the soybean SDS and BRR pathogens revealed that highly conserved regions of three loci were used in the design of these assays, and therefore none were species-specific based on our current understanding of species limits within the SDS–BRR clade. Prompted by this finding, we developed a high-throughput multilocus genotyping (MLGT) assay which accurately differentiated the soybean SDS and two closely related Phaseolus and mung BRR pathogens based on nucleotide polymorphism within the nuclear ribosomal intergenic spacer region rDNA and two anonymous intergenic regions designated locus 51 and 96. The single-well diagnostic assay, employing flow cytometry and a novel fluorescent microsphere array, was validated by independent multilocus molecular phylogenetic analysis of a 65 isolate design panel. The MLGT assay was used to reproducibly type a total of 262 soybean SDS and 9 BRR pathogens. The validated MLGT array provides a unique molecular diagnostic for the accurate identification and molecular surveillance of these economically important plant pathogens.

Occurrence of Stenocarpella macrospora Causing Ear Rot in Corn in the United States

2016 ◽  
Vol 17 (2) ◽  
pp. 152-154
Author(s):  
Martha P. Romero Luna ◽  
Carl A. Bradley ◽  
Heather M. Kelly ◽  
Kiersten A. Wise
Keyword(s):  
United States ◽  
South Africa ◽  
South America ◽  
The United States ◽  
Ear Rot ◽  
Stenocarpella Maydis ◽  
The U.S ◽  
Related Fungus

Diplodia ear rot of corn is primarily caused by the fungus Stenocarpella maydis in the United States. Stenocarpella macrospora is a closely related fungus present in the U.S. but primarily associated with Diplodia leaf streak. S. macrospora is recognized as a major ear rot pathogen in South America and South Africa, but has infrequently been associated with ear rot in the U.S. This brief presents the first reports of Diplodia ear rot in Illinois and Tennessee. This is also the first confirmation of S. macrospora causing ear rot in the U.S. in over 60 years. Accepted for publication 19 May 2016. Published 15 June 2016.

scholarly journals Genomics-Informed Molecular Detection of Xanthomonas vasicola pv. vasculorum Strains Causing Severe Bacterial Leaf Streak of Corn

2020 ◽  
Vol 110 (6) ◽  
pp. 1174-1179 ◽  
Author(s):  
Michael J. Stulberg ◽  
Gem Santillana ◽  
David J. Studholme ◽  
Beth Kasiborski ◽  
Mary Ortiz-Castro ◽  
...  
Keyword(s):  
United States ◽  
South Africa ◽  
Molecular Detection ◽  
Severe Disease ◽  
The United States ◽  
Whole Genome ◽  
Propidium Monoazide ◽  
Bacterial Leaf Streak ◽  
Specific Subset ◽  
Taqman Qpcr

Xanthomonas vasicola pv. vasculorum (syn. X. campestris pv. vasculorum) was initially identified as the causal agent of bacterial leaf streak of corn in South Africa. The pathovar vasculorum causes disease on sugarcane and corn, but a subset of these strains was noted for its increased disease severity in corn. This subset was reclassified as X. campestris pv. zeae in the early 1990s and was found to have slightly different biochemical and genetic properties than isolates from sugarcane. There has been an emergence of X. campestris pv. zeae-like strains of X. vasicola pv. vasculorum in both the United States and Argentina since 2010. We performed whole genome sequencing on U.S. isolates to confirm their identity. Informed by comparative genomics, we then developed specific TaqMan qPCR and loop-mediated isothermal amplification (LAMP) assays for the detection of this specific subset of X. vasicola pv. vasculorum strains. The qPCR 4909 assay was tested against 27 xanthomonads (diverse representation), 32 DNA extractions from corn leaves confirmed as positive or negative for the bacterium, 41 X. vasicola pv. vasculorum isolates from corn in the United States and Argentina, and 31 additional bacteria associated with corn, sugarcane, or sorghum. In all cases the assay was shown to be specific for the X. vasicola pv. vasculorum isolates that cause more severe disease on corn. We then tested the LAMP 166 assay against the 27 xanthomonads and 32 corn leaf DNA samples, and we found this assay was also specific for this subset of X. vasicola pv. vasculorum isolates. We also developed a live/dead cells distinction protocol using propidium monoazide prior to DNA extraction for analyzing seed washes using these assays. These two detection assays can be useful for both diagnosticians and researchers to specifically identify the X. vasicola pv. vasculorum isolates that cause more severe symptoms on corn.

scholarly journals The Requests of Syrians in America to End the Enduring Indifference of the Ottoman Authorities

2019 ◽  
Vol 19 ◽  
pp. 113-128
Author(s):  
Paola Viviani
Keyword(s):  
United States ◽  
New York ◽  
The United States ◽  
Economic Life ◽  
Western Society ◽  
The World ◽  
Critical Issues ◽  
North And South America ◽  
North And South ◽  
Insight Into

The migration of Syrians to America in the 19th and 20th centuries is a major issue which has been widely covered in both fictional and non-fictional literature. Over the same period, many Arab magazines were founded both in North and South America, or “migrated” to those countries. An example is al-Jāmiʿa, which was relocated from Alexandria, Egypt, to New York in 1906, where its founder, the renowned intellectual Faraḥ Anṭūn, was able to undertake a profound study of Western society. Not only did this give him a better insight into that society, but also helped him to better understand the critical issues in his native milieu and the tensions between Turks and Arabs, which often came to the fore, especially when the latter expected the former to help them through important phases of their social, civil, and economic life even in the land they migrated to. This paper analyses an article in al-Jāmiʿa by Nāṣīf Shiblī Damūs, previously published in the epony-mous newspaper, in which Syrian migrants in the United States, with Anṭūn supporting them, lament the indifference of the Ottoman authorities toward them and put forward a number of specific requests, using the magazine as a means of making themselves heard by the entire Arab and Ottoman community throughout the world.

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