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 ◽  
...  

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.

1987 ◽  
Vol 61 (1) ◽  
pp. 112-121 ◽  
Author(s):  
James H. Stitt ◽  
James F. Miller

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.


1970 ◽  
Vol 23 ◽  
pp. 258-270
Author(s):  
Adam Kubasik

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.


2020 ◽  
Vol 110 (6) ◽  
pp. 1124-1131
Author(s):  
Mary Ortiz-Castro ◽  
Terra Hartman ◽  
Teresa Coutinho ◽  
Jillian M. Lang ◽  
Kevin Korus ◽  
...  

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.


2015 ◽  
Vol 113 (4) ◽  
pp. 886-891 ◽  
Author(s):  
Todd A. Surovell ◽  
Spencer R. Pelton ◽  
Richard Anderson-Sprecher ◽  
Adam D. Myers

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.


2001 ◽  
Vol 126 (5) ◽  
pp. 579-586 ◽  
Author(s):  
J.F. Hancock ◽  
C.A. Finn ◽  
S.C. Hokanson ◽  
J.J. Luby ◽  
B.L. Goulart ◽  
...  

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.


2019 ◽  
Vol 19 ◽  
pp. 113-128
Author(s):  
Paola Viviani

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.


2004 ◽  
Vol 25 (2) ◽  
pp. 141-162
Author(s):  
Claudio López-Guerra

Tocqueville proposed that mores or what he called “habits of the heart” were the main reason why a democratic republic—characterized by the mixture of political freedom and equality—had subsisted in the United States.1 After comparing North and South America, Tocqueville went further to argue that the lack of appropriate customs accounted for the fragility of the nascent Latin American republics. This raises a fundamental question: what are the origins of republican mores? Tocqueville concluded that in the United States the social state was the most important factor.


2016 ◽  
Vol 12 (4) ◽  
pp. 20160062 ◽  
Author(s):  
Kieren J. Mitchell ◽  
Sarah C. Bray ◽  
Pere Bover ◽  
Leopoldo Soibelzon ◽  
Blaine W. Schubert ◽  
...  

The Tremarctinae are a subfamily of bears endemic to the New World, including two of the largest terrestrial mammalian carnivores that have ever lived: the giant, short-faced bears Arctodus simus from North America and Arctotherium angustidens from South America (greater than or equal to 1000 kg). Arctotherium angustidens became extinct during the Early Pleistocene, whereas Arctodus simus went extinct at the very end of the Pleistocene. The only living tremarctine is the spectacled bear ( Tremarctos ornatus ), a largely herbivorous bear that is today only found in South America. The relationships among the spectacled bears ( Tremarctos ), South American short-faced bears ( Arctotherium ) and North American short-faced bears ( Arctodus ) remain uncertain. In this study, we sequenced a mitochondrial genome from an Arctotherium femur preserved in a Chilean cave. Our molecular phylogenetic analyses revealed that the South American short-faced bears were more closely related to the extant South American spectacled bear than to the North American short-faced bears. This result suggests striking convergent evolution of giant forms in the two groups of short-faced bears ( Arctodus and Arctotherium ), potentially as an adaptation to dominate competition for megafaunal carcasses.


2020 ◽  
Vol 8 ◽  
Author(s):  
Xia Tang ◽  
Ishani Goonasekara ◽  
Ruvishika Jayawardena ◽  
Hong Jiang ◽  
Jun Li ◽  
...  

Species of the fungal genus Arthrinium (Sordariomycetes, Amphisphaeriales, Apiosporaceae) are often found on bamboo in Asia. They are endophytes, saprobes and important plant pathogens. The genus Arthrinium currently contains 92 species and is widely distributed in North and South America, Europe, Africa, Asia and Oceania. In this study, a new species, Arthrinium bambusicola sp. nov., is described and illustrated. The new taxon is characterised by oval to broadly or irregularly round, medium brown, multi-guttulate to roughened, granular conidia, with finely pale slits in the outer edges. Arthrinium bambusicola can be distinguished from the closest related species A. gutiae by its conidial characteristics. Phylogenetic analyses of a four-locus dataset (ITS, LSU, TEF1, TUB2) confirm that A. bambusicola is a distinct new species.


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