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You searched for +publisher:"Rutgers University" +contributor:("Polashock, James"). Showing records 1 – 2 of 2 total matches.

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Rutgers University

1. Behringer, Gregory. The genetic characterization of Northeastern Quercus associated Xylella fastidiosa populations.

Degree: PhD, Plant Biology, 2015, Rutgers University

Xylella fastidiosa is broad-host-range plant pathogen responsible for significant commodity crop damage in much of the Western Hemisphere. Since its description in 1892, focus has centered around disease associated with Vitis (grape) hosts. Shade tree host studies of X. fastidiosa populations, however, have been both sparse and regionally oriented, making the exploration of infected oak stands an important area for greater understanding of this phytopathogen. To describe novel genetic profiles of the oak associated pathogen, Northeastern and Mid-Atlantic populations were assessed both phylogenetically and with Principal Component Analyses (PCA) and Minimum Spanning Trees (MSN). Polymerase chain reaction (PCR) based locus recoveries identified previously undescribed genetic diversity and phylogenetically separated oak associated populations based on host geography. Expanded analysis of insertion/deletion regions associated with the oak pathogen was also conducted for fine separation of populations relative to phylogenetic recoveries. Together these provided an efficient means to track the spread of the pathogen at the population level. To further explore genetic diversity in understudied X. fastidiosa oak populations, the genome of a Northeastern Quercus palustris associated X. fastidiosa isolate, RNB1, was sequenced and analyzed. Existing isolate comparisons described several novel RNB1 genomic regions, including two potential vir genes, and a Gene Ontology procyclic repeat pathogenesis locus. This work provided the first comparative look at an oak associated X. fastidiosa genome and described its composition relative to well described isolates. A final search for novel population specific markers in X. fastidiosa colonies targeted prophage segments. Thirteen regions across nineteen genomes were qualitatively described, with phage repressor and terminase suggestive of previously confirmed phylogenetic relatedness at an integrated phage-based locus. This data was then used in several machine learning approaches and proved accurate in predicting taxonomic categories across disparate X. fastidiosa populations when trained with matrix transforms of host specific X. fastidiosa prophage regions. This final study described evolutionary significance of widely profiled prophage regions and introduced an algorithmic approach for future large-scale genetically themed X. fastidiosa based population studies. Overall, the work herein presents previously undescribed genetic aspects of oak associated X. fastidiosa populations and posits a novel method for future data synthesis.

Advisors/Committee Members: Kobayashi, Donald Y (chair), Oudemans, Peter (internal member), Gould, Ann Brooks (internal member), Zhang, Ning (internal member), Polashock, James (outside member).

Subjects/Keywords: Oak – Diseases and pests

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Behringer, G. (2015). The genetic characterization of Northeastern Quercus associated Xylella fastidiosa populations. (Doctoral Dissertation). Rutgers University. Retrieved from https://rucore.libraries.rutgers.edu/rutgers-lib/48391/

Chicago Manual of Style (16th Edition):

Behringer, Gregory. “The genetic characterization of Northeastern Quercus associated Xylella fastidiosa populations.” 2015. Doctoral Dissertation, Rutgers University. Accessed January 15, 2021. https://rucore.libraries.rutgers.edu/rutgers-lib/48391/.

MLA Handbook (7th Edition):

Behringer, Gregory. “The genetic characterization of Northeastern Quercus associated Xylella fastidiosa populations.” 2015. Web. 15 Jan 2021.

Vancouver:

Behringer G. The genetic characterization of Northeastern Quercus associated Xylella fastidiosa populations. [Internet] [Doctoral dissertation]. Rutgers University; 2015. [cited 2021 Jan 15]. Available from: https://rucore.libraries.rutgers.edu/rutgers-lib/48391/.

Council of Science Editors:

Behringer G. The genetic characterization of Northeastern Quercus associated Xylella fastidiosa populations. [Doctoral Dissertation]. Rutgers University; 2015. Available from: https://rucore.libraries.rutgers.edu/rutgers-lib/48391/


Rutgers University

2. Waller, Timothy James, 1986-. Blueberry and cranberry floral stimulation of Colletotrichum fioriniae and other fruit rotting fungi.

Degree: PhD, Plant Biology, 2019, Rutgers University

Colletotrichum fioriniae is an important hemibiotrophic pathogen limiting both highbush blueberry (Vaccinium corymbosum L.) and cranberry (V. macrocarpon Aiton) production worldwide. Since fungicide applications during bloom are most effective in both crops, the link between host floral signals and pathogen disease cycles were investigated. C. fioriniae as well as two other latent infection forming cranberry fruit rot pathogens C. fructivorum (C. gloeosporioides s.l.) and Coleophoma cylindrospora (C. empetri s.l.) and a mature fruit infecting fungi Allantophomopsis lycopodena were investigated to better describe the temporal dynamics of pathogen stimulation in response to host derived signals produced during bloom. In order quantify this relationship and visualize pathogen responses, host signals isolated via water or chloroform were utilized in extract-dependent bioassays. The results showed that blueberry and cranberry (as well as multiple other ericaceous species) floral extracts (FEs) affected two important disease cycle stages by stimulating an increased rate (+ 200%) and quantity (+ 500%) of secondary conidiation (inoculum build-up) and appressorial formation (infection structures) of C. fioriniae and all other pathogens evaluated, except A. lycopodena, linking bloom period infecting fungi to floral signals. Conidia in the presence of FEs also conferred higher levels of disease on detached fruit than conidia alone, suggesting that apparent disease was a function of increased appressorial formation. Bioactivity was readily detected in floral rainwater runoff and became more stimulatory as proximity to flowers or the bloom period increased, thus indicating both mobility of floral signals and the importance of phenology-specific cues. Chloroform-based extractions provided a chemical mirror of the host cuticles first encountered by pathogens. Characterization of multiple tissue types elucidated fatty acid derivative compositional patterns, where specific stimulatory compounds were more abundant in flower cuticular waxes. Multiple fatty acids were identified that stimulated appressorial formation, however, hexadecanoic fatty acid derivatives were concluded to be the most likely source of stimulation due to the paired bioactivity observations and occurrence of this compound within both water- and chloroform-based extraction types. This research provides strong evidence that flowers contribute substantially to the disease cycle events of replication (sporulation and secondary conidiation) and infection of fruit by C. fioriniae and other bloom period infecting fungi, thus providing evidence as to why the bloom period is often referred to as the critical disease control window.

Advisors/Committee Members: Oudemans, Peter V. (chair), Hillman, Bradley I. (internal member), Kobayashi, Donald Y. (internal member), Polashock, James J. (outside member), School of Graduate Studies.

Subjects/Keywords: Colletotrichum; Blueberries  – Diseases and pests; Cranberries  – Diseases and pests

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Waller, Timothy James, 1. (2019). Blueberry and cranberry floral stimulation of Colletotrichum fioriniae and other fruit rotting fungi. (Doctoral Dissertation). Rutgers University. Retrieved from https://rucore.libraries.rutgers.edu/rutgers-lib/61977/

Chicago Manual of Style (16th Edition):

Waller, Timothy James, 1986-. “Blueberry and cranberry floral stimulation of Colletotrichum fioriniae and other fruit rotting fungi.” 2019. Doctoral Dissertation, Rutgers University. Accessed January 15, 2021. https://rucore.libraries.rutgers.edu/rutgers-lib/61977/.

MLA Handbook (7th Edition):

Waller, Timothy James, 1986-. “Blueberry and cranberry floral stimulation of Colletotrichum fioriniae and other fruit rotting fungi.” 2019. Web. 15 Jan 2021.

Vancouver:

Waller, Timothy James 1. Blueberry and cranberry floral stimulation of Colletotrichum fioriniae and other fruit rotting fungi. [Internet] [Doctoral dissertation]. Rutgers University; 2019. [cited 2021 Jan 15]. Available from: https://rucore.libraries.rutgers.edu/rutgers-lib/61977/.

Council of Science Editors:

Waller, Timothy James 1. Blueberry and cranberry floral stimulation of Colletotrichum fioriniae and other fruit rotting fungi. [Doctoral Dissertation]. Rutgers University; 2019. Available from: https://rucore.libraries.rutgers.edu/rutgers-lib/61977/

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