Date of Award

2011

Publisher

North Dakota State University

Document Type

Dissertation

Degree Awarded

Doctor of Philosophy (PhD)

Program

Genomics and Bioinformatics

Department

Genomics, Phenomics, and Bioinformatics

College

Interdisciplinary Studies

Faculty Advisor

Faris, Justin D.

Description

Host-selective toxins, or necrotrophic effectors, are important determinants of disease in both wheat-Stagonospora nodorum and wheat- Pyrenophora tritici-repentis pathosystems. This study describes the identification, validation, and genomic analysis of compatible host gene-effector interactions in these systems. In the wheat-S. nodorum system, the Snn4-SnTox4 interaction was identified and validated using the hexaploid wheat ( Tri ti cum aestivum L.) recombinant inbred populations 'Arina' x 'Forno' ( AF) and Salamouni x 'Katepwa' (SK), respectively. The single dominant gene, Snn4, which mapped to the short arm of chromosome 1 A in both populations, governs sensitivity to the proteinaceous effector, SnTox4, which is estimated to be 10-30 kDa in size. The compatible Snn4-SnTox4 interaction played a significant role in disease development in both the AF and SK populations accounting for 41 % and 23.5% of the phenotypic variation, respectively. Effects of the additional minor QTL were largely additive in both genetic backgrounds. Molecular mapping in the SK population using microsatellites and markers developed using bin-mapped expressed sequence tags (ESTs), and from ESTs identified based on colinear studies with rice (Oryza sativa L.) and Brachypodium, delineated Tsc2 to a 3.3 cM interval and confirmed its location on 2BS of hexaploid wheat. The compatible T.~c2-Ptr ToxB interaction accounted for 54% of the disease variation in the SK population. The marker XBE44454 l, which co-segregated with Tsc2 is diagnostic of the gene and will be useful in marker-assisted selection (MAS).

Rights

NDSU policy 190.6.2

Rights Link

https://www.ndsu.edu/fileadmin/policy/190.pdf

Handle Identifier

https://hdl.handle.net/10365/33473

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