Mapping and Characterization of Phytophthora sojae and Soybean Mosaic Virus Resistance in Soybean

Phytophthora sojae, the causal organism of stem and root rot, and <i>Soybean mosaic virus</i> (SMV) cause two of the most highly destructive diseases of soybean (<i>Glycine max</i> L. Merr). <i>P. sojae</i> can be managed either through deployment of race-specific resistance or through quantitative resistance termed partial resistance. In the current study, partial resistance to <i>P. sojae</i> was mapped in an interspecific recombinant inbred line (RIL) population of <i>Glycine max</i> by <i>Glycine soja</i>. One major quantitative trait loci (QTL) on molecular linkage group (MLG)-J (chromosome 16) and two minor QTL on MLG-I (chromosome 20) and -G (chromosome 18) were mapped using conventional molecular markers. Additionally, partial resistance to <i>P. sojae</i> was mapped in the same RIL population using single feature polymorphism (SFP) markers that further fine mapped the <i>P. sojae</i> QTL and identified potential candidate genes contributing to resistance. In a separate study, race-specific resistance was characterized in PI96983 discovering a potentially new allele of <i>Rps4</i> on MLG-G. Finally, using the newly available whole-genome shotgun sequence of soybean, <i>Rsv4</i> conferring resistance to strains of SMV known in the US, was localized to an approximately 100 kb region of sequence on chromosome 2 (MLG-D1B). Newly designed PCR-based markers permit for efficient selection of <i>Rsv4</i> by breeding programs. Identified candidate genes for <i>Rsv4</i> are discussed. Genomic resources developed in all of these studies provide breeders the tools necessary for developing durable resistance to both SMV and <i>P. sojae</i>.

Name thesis:degree_name

Ph. D.

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Crop and Soil Environmental Sciences

Department dc:contributor.department

Crop and Soil Environmental Sciences

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2009

Author dc:creator

• Tucker, Dominic M.

Chair dc:contributor.committeechair

• Saghai-Maroof, Mohammad A.

Committee members dc:contributor.committeemember

• Tolin, Sue A.
• Jelesko, John G.
• Rainey, Katy Martin
• Tyler, Brett M.

• Single feature polymorphism
• Phytophthora megasperma
• Durable resistance
• Late susceptible
• Simple sequence repeat
• Marker-assisted selection

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en_US

Dc Identifier Other

etd-05042009-134450

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/79598