Efforts are underway to restore the American chestnut, Castanea dentata (Marsh.) Borkh, to its original range within the United States. The American Chestnut Foundation has traditionally focused on introducing blight resistance of the Chinese chestnut, C. mollissima Blume, into their breeding stock. Now, however, they are encountering problems with a root rot caused by Phytophthora cinnamomi Rands, and the threat of a potential disease caused by Phytophthora ramorum Werres, De Cock, and Man in?t Venld. In order for the Foundation to breed for resistance against the effects of these pathogens, much more needs to be discovered regarding their interactions within Castanea. This thesis is part of the effort to understand these interactions. The first chapter provides a literature review of interactions for two Phytophthora species and Castanea spp. The second chapter presents experiments investigating the mode of inheritance and number of loci controlling resistance to each of these Phytophthora species. Initial experimentation appears to suggest that resistance to P. cinnamomi may be controlled by a single dominant gene in chestnut, but conclusive evidence from subsequent experiments was not found; possible causes are discussed. A series of screening assays based on leaf disk assays using P. ramorum also failed to provide conclusive evidence that a single locus controls the degree of response, but statistically significant differences were noted among seedlots in each trial, suggesting some level of genetic control. The third chapter presents a genetic linkage map developed from amplified fragment length polymorphic (AFLP) markers for the F1 parent in a backcross family ((C. mollissima ?Mahogany? x C. dentata ?RCF1? = ?KY115?) x C. dentata ?WB348?). This purpose of this map is to correlate future resistance segregation patterns from controlled P. cinnamomi inoculation trials with specific marker loci. This would provide a foundation for future genetic research regarding the number of loci controlling resistance to root rot caused by P. cinnamomi and its relationship with other traits of interest in chestnuts.
| Identifer | oai:union.ndltd.org:NCSU/oai:NCSU:etd-08162006-093218 |
| Date | 13 September 2006 |
| Creators | Bowles, Mollie Ellen |
| Contributors | Dr. John Frampton, Dr. Henry Amerson, Dr. Larry Grand |
| Publisher | NCSU |
| Source Sets | North Carolina State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://www.lib.ncsu.edu/theses/available/etd-08162006-093218/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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