scholarly journals Genetic differentiation of Xylella fastidiosa following the introduction into Taiwan

2021 ◽  
Author(s):  
Andreina I. Castillo ◽  
Chi-Wei Tsai ◽  
Chiou-Chu Su ◽  
Ling-Wei Weng ◽  
Yu-Chen Lin ◽  
...  

The economically important plant pathogen Xylella fastidiosa has been reported in multiple regions of the globe during the last two decades, threatening a growing list of crops and industries. Xylella fastidiosa subspecies fastidiosa causes disease in grapevines (Pierce's disease of grapevines, PD), a current problem in the United States (US), Spain, and Taiwan. We studied PD-causing subsp. fastidiosa populations and compared the genome sequences of 33 isolates found in Central Taiwan with 171 isolates from the US and two from Spain. Phylogenetic relationships, haplotype network, and genetic diversity analyses confirm that subsp. fastidiosa was recently introduced into Taiwan from the Southeast US (i.e., the PD-I lineage in Georgia based on available data). Recent core genome recombination events were detected among introduced subsp. fastidiosa isolates in Taiwan and contributed to the development of genetic diversity, particularly in the Houli District of Taichung City in Central Taiwan. Unexpectedly, despite comprehensive sampling of all regions with high PD incidences in Taiwan, the genetic diversity observed include contributions through recombination from unknown donors, suggesting that higher diversity exists in the region. Nevertheless, no recombination event was detected between X. fastidiosa subsp. fastidiosa and the endemic sister species Xylella taiwanensis. In summary, this study improved our understanding of the genetic diversity of PD-causing subsp. fastidiosa after invasion to a new region.

2021 ◽  
Vol 7 (12) ◽  
Author(s):  
Andreina I. Castillo ◽  
Chi-Wei Tsai ◽  
Chiou-Chu Su ◽  
Ling-Wei Weng ◽  
Yu-Chen Lin ◽  
...  

The economically important plant pathogen Xylella fastidiosa has been reported in multiple regions of the globe during the last two decades, threatening a growing list of plants. Particularly, X. fastidiosa subspecies fastidiosa causes Pierce’s disease (PD) of grapevines, which is a problem in the USA, Spain, and Taiwan. In this work, we studied PD-causing subsp. fastidiosa populations and compared the genome sequences of 33 isolates found in Central Taiwan with 171 isolates from the USA and two from Spain. Phylogenetic relationships, haplotype networks, and genetic diversity analyses confirmed that subsp. fastidiosa was recently introduced into Taiwan from the Southeast USA (i.e. the PD-I lineage). Recent core-genome recombination events were detected among introduced subsp. fastidiosa isolates in Taiwan and contributed to the development of genetic diversity. The genetic diversity observed includes contributions through recombination from unknown donors, suggesting that higher genetic diversity exists in the region. Nevertheless, no recombination event was detected between X. fastidiosa subsp. fastidiosa and the endemic sister species Xylella taiwanensis , which is the causative agent of pear leaf scorch disease. In summary, this study improved our understanding of the genetic diversity of an important plant pathogenic bacterium after its invasion to a new region.


Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1446
Author(s):  
Lorraine Rodriguez-Bonilla ◽  
Karen A. Williams ◽  
Fabian Rodríguez Bonilla ◽  
Daniel Matusinec ◽  
Andrew Maule ◽  
...  

Knowledge of the genetic diversity in populations of crop wild relatives (CWR) can inform effective strategies for their conservation and facilitate utilization to solve agricultural challenges. Two crop wild relatives of the cultivated cranberry are widely distributed in the US. We studied 21 populations of Vaccinium macrocarpon Aiton and 24 populations of Vaccinium oxycoccos L. across much of their native ranges in the US using 32 simple sequence repeat (SSR) markers. We observed high levels of heterozygosity for both species across populations with private alleles ranging from 0 to 26. For V. macrocarpon, we found a total of 613 alleles and high levels of heterozygosity (HO = 0.99, HT = 0.75). We also observed high numbers of alleles (881) and levels of heterozygosity (HO = 0.71, HT = 0.80) in V. oxycoccos (4x). Our genetic analyses confirmed the field identification of a native population of V. macrocarpon on the Okanogan-Wenatchee National Forest in the state of Washington, far outside the previously reported range for the species. Our results will help to inform efforts of the United States Department of Agriculture Agricultural Research Service (USDA-ARS) and the United States Forest Service (USFS) to conserve the most diverse and unique wild cranberry populations through ex situ preservation of germplasm and in situ conservation in designated sites on National Forests.


Genes ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 2007
Author(s):  
A. S. M. Faridul Islam ◽  
Dean Sanders ◽  
Amit Kumar Mishra ◽  
Vijay Joshi

Olives are one of the most important fruit and woody oil trees cultivated in many parts of the world. Olive oil is a critical component of the Mediterranean diet due to its importance in heart health. Olives are believed to have been brought to the United States from the Mediterranean countries in the 18th century. Despite the increase in demand and production areas, only a few selected olive varieties are grown in most traditional or new growing regions in the US. By understanding the genetic background, new sources of genetic diversity can be incorporated into the olive breeding programs to develop regionally adapted varieties for the US market. This study aimed to explore the genetic diversity and population structure of 90 olive accessions from the USDA repository along with six popular varieties using genotyping-by-sequencing (GBS)-generated SNP markers. After quality filtering, 54,075 SNP markers were retained for the genetic diversity analysis. The average gene diversity (GD) and polymorphic information content (PIC) values of the SNPs were 0.244 and 0.206, respectively, indicating a moderate genetic diversity for the US olive germplasm evaluated in this study. The structure analysis showed that the USDA collection was distributed across seven subpopulations; 63% of the accessions were grouped into an identifiable subpopulation. The phylogenetic and principal coordinate analysis (PCoA) showed that the subpopulations did not align with the geographical origins or climatic zones. An analysis of the molecular variance revealed that the major genetic variation sources were within populations. These findings provide critical information for future olive breeding programs to select genetically distant parents and facilitate future gene identification using genome-wide association studies (GWAS) or a marker-assisted selection (MAS) to develop varieties suited to production in the US.


Plant Disease ◽  
2021 ◽  
pp. PDIS-09-20-1900
Author(s):  
Andrés Aguilar-Granados ◽  
Bárbara Hernández-Macías ◽  
Guillermo Santiago-Martínez ◽  
Roberto Ruiz-Medrano ◽  
Luis Kameyama-Kawabe ◽  
...  

Xylella fastidiosa is a xylem-inhabiting phytopathogenic bacterium that affects diverse agriculturally relevant crops. In Mexico, X. fastidiosa has been reported in the states of Baja California, Coahuila, and Querétaro. In order to determine the genetic diversity of this bacterium in Mexico, 408 grapevine samples were collected from the main producing states in México. For X. fastidiosa identification, real-time PCR and three-loci end-point PCR were employed. The genotyping of the subspecies was carried out using multilocus sequence typing and analysis, based on seven housekeeping genes: leuA, petC, malF, cysG, holC, nuoL, and gltT. The resulting sequences were compared with those present in extant databases. The presence of X. fastidiosa subsp. fastidiosa in the states of Baja California (sequence type 1), Coahuila (sequence type 1), and Querétaro was confirmed. The isolates from northern Mexico bear high similarity to grapevine isolates from the United States. However, the isolates from Querétaro showed significant differences with currently known sequences, showing that there is genetic variability among the X. fastidiosa subsp. fastidiosa populations from grapevines in northern and central Mexico.


2000 ◽  
Vol 16 (2) ◽  
pp. 107-114 ◽  
Author(s):  
Louis M. Hsu ◽  
Judy Hayman ◽  
Judith Koch ◽  
Debbie Mandell

Summary: In the United States' normative population for the WAIS-R, differences (Ds) between persons' verbal and performance IQs (VIQs and PIQs) tend to increase with an increase in full scale IQs (FSIQs). This suggests that norm-referenced interpretations of Ds should take FSIQs into account. Two new graphs are presented to facilitate this type of interpretation. One of these graphs estimates the mean of absolute values of D (called typical D) at each FSIQ level of the US normative population. The other graph estimates the absolute value of D that is exceeded only 5% of the time (called abnormal D) at each FSIQ level of this population. A graph for the identification of conventional “statistically significant Ds” (also called “reliable Ds”) is also presented. A reliable D is defined in the context of classical true score theory as an absolute D that is unlikely (p < .05) to be exceeded by a person whose true VIQ and PIQ are equal. As conventionally defined reliable Ds do not depend on the FSIQ. The graphs of typical and abnormal Ds are based on quadratic models of the relation of sizes of Ds to FSIQs. These models are generalizations of models described in Hsu (1996) . The new graphical method of identifying Abnormal Ds is compared to the conventional Payne-Jones method of identifying these Ds. Implications of the three juxtaposed graphs for the interpretation of VIQ-PIQ differences are discussed.


2009 ◽  
Vol 2 (1) ◽  
pp. 1-27
Author(s):  
Ann Abate Michelle

This essay argues that in spite of their obvious Biblically-based subject matter, clear Christian content, and undeniable evangelical perspective, the Left Behind novels for kids are not simply religious books; they are also political ones. Co-authors Tim LaHaye and Jerry B. Jenkins may claim that their narratives are interested in sharing the good news about Jesus for the sake of the future, but they are equally concerned with offering commentary on contentious US cultural issues in the present. Given the books’ adolescent readership, they are especially preoccupied with the ongoing conservative crusade concerning school prayer. As advocates for this issue, LaHaye and Jenkins make use of a potent blend of current socio-political arguments and of past events in evangelical church history: namely, the American Sunday School Movement (ASSM). These free, open-access Sabbath schools became the model for the public education system in the United States. In drawing on this history, the Left Behind series suggests that the ASSM provides an important precedent for the presence not simply of Christianity in the nation's public school system, but of evangelical faith in particular.


Author(s):  
Steven Hurst

The United States, Iran and the Bomb provides the first comprehensive analysis of the US-Iranian nuclear relationship from its origins through to the signing of the Joint Comprehensive Plan of Action (JCPOA) in 2015. Starting with the Nixon administration in the 1970s, it analyses the policies of successive US administrations toward the Iranian nuclear programme. Emphasizing the centrality of domestic politics to decision-making on both sides, it offers both an explanation of the evolution of the relationship and a critique of successive US administrations' efforts to halt the Iranian nuclear programme, with neither coercive measures nor inducements effectively applied. The book further argues that factional politics inside Iran played a crucial role in Iranian nuclear decision-making and that American policy tended to reinforce the position of Iranian hardliners and undermine that of those who were prepared to compromise on the nuclear issue. In the final chapter it demonstrates how President Obama's alterations to American strategy, accompanied by shifts in Iranian domestic politics, finally brought about the signing of the JCPOA in 2015.


2014 ◽  
Vol 23 (3) ◽  
pp. 381-388 ◽  
Author(s):  
Euan Hague ◽  
Alan Mackie

The United States media have given rather little attention to the question of the Scottish referendum despite important economic, political and military links between the US and the UK/Scotland. For some in the US a ‘no’ vote would be greeted with relief given these ties: for others, a ‘yes’ vote would be acclaimed as an underdog escaping England's imperium, a narrative clearly echoing America's own founding story. This article explores commentary in the US press and media as well as reporting evidence from on-going interviews with the Scottish diaspora in the US. It concludes that there is as complex a picture of the 2014 referendum in the United States as there is in Scotland.


2018 ◽  
Vol 47 (3) ◽  
pp. 130-134

This section, updated regularly on the blog Palestine Square, covers popular conversations related to the Palestinians and the Arab-Israeli conflict during the quarter 16 November 2017 to 15 February 2018: #JerusalemIstheCapitalofPalestine went viral after U.S. president Donald Trump recognized Jerusalem as the capital of Israel and announced his intention to move the U.S. embassy there from Tel Aviv. The arrest of Palestinian teenager Ahed Tamimi for slapping an Israeli soldier also prompted a viral campaign under the hashtag #FreeAhed. A smaller campaign protested the exclusion of Palestinian human rights from the agenda of the annual Creating Change conference organized by the US-based National LGBTQ Task Force in Washington. And, UNRWA publicized its emergency funding appeal, following the decision of the United States to slash funding to the organization, with the hashtag #DignityIsPriceless.


2019 ◽  
Vol 35 (2) ◽  
pp. 143-170
Author(s):  
Gerardo Gurza-Lavalle

This work analyses the diplomatic conflicts that slavery and the problem of runaway slaves provoked in relations between Mexico and the United States from 1821 to 1857. Slavery became a source of conflict after the colonization of Texas. Later, after the US-Mexico War, slaves ran away into Mexican territory, and therefore slaveholders and politicians in Texas wanted a treaty of extradition that included a stipulation for the return of fugitives. This article contests recent historiography that considers the South (as a region) and southern politicians as strongly influential in the design of foreign policy, putting into question the actual power not only of the South but also of the United States as a whole. The problem of slavery divided the United States and rendered the pursuit of a proslavery foreign policy increasingly difficult. In addition, the South never acted as a unified bloc; there were considerable differences between the upper South and the lower South. These differences are noticeable in the fact that southerners in Congress never sought with enough energy a treaty of extradition with Mexico. The article also argues that Mexico found the necessary leeway to defend its own interests, even with the stark differential of wealth and resources existing between the two countries. El presente trabajo analiza los conflictos diplomáticos entre México y Estados Unidos que fueron provocados por la esclavitud y el problema de los esclavos fugitivos entre 1821 y 1857. La esclavitud se convirtió en fuente de conflicto tras la colonización de Texas. Más tarde, después de la guerra Mexico-Estados Unidos, algunos esclavos se fugaron al territorio mexicano y por lo tanto dueños y políticos solicitaron un tratado de extradición que incluyera una estipulación para el retorno de los fugitivos. Este artículo disputa la idea de la historiografía reciente que considera al Sur (en cuanto región), así como a los políticos sureños, como grandes influencias en el diseño de la política exterior, y pone en tela de juicio el verdadero poder no sólo del Sur sino de Estados Unidos en su conjunto. El problema de la esclavitud dividió a Estados Unidos y dificultó cada vez más el impulso de una política exterior que favoreciera la esclavitud. Además, el Sur jamás operó como unidad: había diferencias marcadas entre el Alto Sur y el Bajo Sur. Estas diferencias se observan en el hecho de que los sureños en el Congreso jamás se esforzaron en buscar con suficiente energía un tratado de extradición con México. El artículo también sostiene que México halló el margen de maniobra necesario para defender sus propios intereses, pese a los fuertes contrastes de riqueza y recursos entre los dos países.


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