The goal
of my research is to understand the genetic bases of plant host-pathogen
interactions, at both the molecular and population levels. This information
will be used to increase the level of resistance in cereal crops to
foliar diseases caused by fungi.
Septoria
disease of wheat, caused by the two fungi Mycosphaerella graminicola
(anamorph Septoria tritici) and Phaeosphaeria (Septoria) nodorum,
is an economically important disease that occurs throughout the world.
Analyses of the population genetics of these pathogens in Indiana are
being conducted to reveal the primary sources of inoculum, the extent
of gene flow among populations and the modes of reproduction during
epidemics. Methods for genetic analyses of P. nodorum have been
developed recently and are being applied to elucidate the genetic basis
of pathogenicity. The number of genes involved in pathogenicity and
their mode of action are still not known. Molecular markers (including
RFLP, RAPD, AFLP and microsatellite technologies) are being used to
develop genetic maps and identify the chromosomal locations for pathogenicity
genes and other traits of biological interest. Another aspect of my
research is to use phylogenetic analyses to determine the evolutionary
relationships among both septoria pathogens and their nearest relatives.
Understanding the mechanisms of speciation in pathogenic fungi could
indicate new approaches for developing improved disease management strategies.
Work with
the host is focused on identifying genes for resistance in wheat, and
on finding molecular markers that are closely linked to resistance genes.
Molecular markers that tag known resistance genes will be used to facilitate
the incorporation of resistance into wheat through plant breeding programs.
Genetic analyses of resistance and of molecular markers will aid the
eventual cloning and molecular characterization of plant genes for resistance
to foliar fungal pathogens.
Goodwin, S. B., C. Waalwijk, G. H. J. Kema, J.
R. Cavaletto, and G. Zhang. 2003. Cloning and analysis of the mating-type
idiomorphs from the barley pathogen Septoria passerinii. Molecular
Genetics and Genomics 269: 1-12.
Grünwald,
N. J., S. B. Goodwin, M. G. Milgroom,
and W. E. Fry. 2003. Analysis of genotypic diversity data for populations
of microorganisms. Phytopathology 93: 738-746.
Adhikari,
T. B., J. M. Anderson, and S. B. goodwin.
2003. Identification and molecular mapping of a
gene in wheat conferring resistance to Mycosphaerella graminicola. Phytopathology 93:
1158-1164.
Ray, S., J. M. Anderson, F. I. Urmeev, and S. B. Goodwin.
2003. Rapid induction of a protein disulfide isomerase and defense-related
genes in wheat in response to the hemibiotrophic fungal pathogen Mycosphaerella
graminicola. Plant Molecular Biology 53: 741-754.
Adhikari,
T. B., H. Wallwork, and S. B. Goodwin.
2004. Microsatellite markers linked to the Stb2 and Stb3 genes
for resistance to septoria tritici blotch in wheat. Crop Science 44:
1403-1411.
Goodwin, S. B. 2004. Minimum
phylogenetic coverage: an additional criterion to guide the selection
of microbial pathogens for initial genomic sequencing efforts.Phytopathology 94:
800-804.
Adhikari,
T. B., X. Yang, J. R. Cavaletto, X. Hu, G. Buechley, H. W. Ohm, G.
Shaner, and S. B. Goodwin. 2004. Molecular
mapping of Stb1, a potentially durable gene for resistance
to septoria tritici blotch in wheat. Theoretical and Applied
Genetics 109: 944-953.
Adhikari, T. B., J. R. Cavaletto, J. Dubcovsky, J. Gieco, A. R.
Schlatter, and S. B. Goodwin. 2004. Molecular mapping
of the Stb4 geneforresistance to septoria tritici blotch
in wheat. Phytopathology 94: 1198-1206.
Goodwin, S. B., T. A. J. van der Lee, J. R. Cavaletto,
B. te Lintel-Hekkert, C. F. Crane, and G. H. J. Kema. 2007. Identification
and genetic mapping of highly polymorphic microsatellite loci from
an EST database of the septoria tritici blotch pathogen Mycosphaerella
graminicola. Fungal Genetics and Biology 44:
398-414.
Faculty